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Sample records for suppressor gene frequently

  1. TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Wang, Shumin; Ma, Ning; Murata, Mariko; Huang, Guangwu; Zhang, Zhe; Xiao, Xue; Zhou, Xiaoying; Huang, Tingting; Du, Chunping; Yu, Nana; Mo, Yingxi; Lin, Longde; Zhang, Jinyan

    2010-01-01

    Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, TFPI-2 was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether TFPI-2 was inactivated epigenetically in nasopharyngeal carcinoma (NPC). Transcriptional expression levels of TFPI-2 was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of TFPI-2 as a tumor suppressor gene in NPC was addressed by re-introducing TFPI-2 expression into the NPC cell line CNE2. TFPI-2 mRNA transcription was inactivated in NPC cell lines. TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. TFPI-2 expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration. Epigenetic inactivation of TFPI-2 by promoter hypermethylation is a frequent and tumor specific event in NPC. TFPI-2 might be considering as a putative tumor suppressor gene in NPC

  2. Tumor suppressor genes are frequently methylated in lymph node metastases of breast cancers

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    Xu Jia

    2010-07-01

    Full Text Available Abstract Introduction Metastasis represents a major adverse step in the progression of breast carcinoma. Lymph node invasion is the most relevant prognostic factor; however little is known on the molecular events associated with lymph node metastasis process. This study is to investigate the status and role of methylation in lymph node metastatic tumors. Materials and methods Bisulfite pyrosequencing is used to screen 6 putative tumor suppressor genes (HIN-1, RASSF1A, RIL, CDH13, RARβ2 and E-cadherin in 38 pairs of primary breast tumors and lymph node metastases. Results We found that HIN-1, CDH13, RIL, RASSF1A and RARβ2 were frequently methylated both in primary and metastatic tissues (range: 55.3%~89.5%. E-cadherin was not frequently methylated in either setting (range: 18.4%~23.7%. The methylation status of HIN-1, CDH13, RIL, and RARβ2 in lymph nodes metastasis were correlated with that in primary tumors. The Pearson correlation values ranged from 0.624 to 0.472 (p values HIN-1 methylation and hormone status in metastatic lymph nodes. Hypermethylation of HIN-1 in metastasis lymph nodes was significantly associated with expression of ER (odds ratio, 1.070; P = 0.024 and with PR (odds ratio, 1.046; P = 0.026. Conclusions This study suggests that hypermethylation of tumor suppressor genes is extended from primary to metastatic tumors during tumor progression.

  3. The potential for tumor suppressor gene therapy in head and neck cancer.

    Science.gov (United States)

    Birkeland, Andrew C; Ludwig, Megan L; Spector, Matthew E; Brenner, J Chad

    2016-01-01

    Head and neck squamous cell carcinoma remains a highly morbid and fatal disease. Importantly, genomic sequencing of head and neck cancers has identified frequent mutations in tumor suppressor genes. While targeted therapeutics increasingly are being investigated in head and neck cancer, the majority of these agents are against overactive/overexpressed oncogenes. Therapy to restore lost tumor suppressor gene function remains a key and under-addressed niche in trials for head and neck cancer. Recent advances in gene editing have captured the interest of both the scientific community and the public. As our technology for gene editing and gene expression modulation improves, addressing lost tumor suppressor gene function in head and neck cancers is becoming a reality. This review will summarize new techniques, challenges to implementation, future directions, and ethical ramifications of gene therapy in head and neck cancer.

  4. The novel RASSF6 and RASSF10 candidate tumour suppressor genes are frequently epigenetically inactivated in childhood leukaemias

    Directory of Open Access Journals (Sweden)

    Maher Eamonn R

    2009-07-01

    Full Text Available Abstract Background The Ras-assocation family (RASSF of tumour suppressor genes (TSGs contains 10 members that encode proteins containing Ras-assocation (RA domains. Several members of the RASSF family are frequently epigenetically inactivated in cancer, however, their role in leukaemia has remained largely uninvestigated. Also, RASSF10 is a predicted gene yet to be experimentally verified. Here we cloned, characterised and demonstrated expression of RASSF10 in normal human bone marrow. We also determined the methylation status of CpG islands associated with RASSF1–10 in a series of childhood acute lymphocytic leukaemias (ALL and normal blood and bone marrow samples. Results COBRA and bisulphite sequencing revealed RASSF6 and RASSF10 were the only RASSF members with a high frequency of leukaemia-specific methylation. RASSF6 was methylated in 94% (48/51 B-ALL and 41% (12/29 T-ALL, whilst RASSF10 was methylated in 16% (8/51 B-ALL and 88% (23/26 T-ALL. RASSF6 and RASSF10 expression inversely correlated with methylation which was restored by treatment with 5-aza-2'deoxycytidine (5azaDC. Conclusion This study shows the hypermethylation profile of RASSF genes in leukaemias is distinct from that of solid tumours and represents the first report of inactivation of RASSF6 or RASSF10 in cancer. These data show epigenetic inactivation of the candidate TSGs RASSF6 and RASSF10 is an extremely frequent event in the pathogenesis of childhood leukaemia. This study also warrants further investigation of the newly identified RASSF member RASSF10 and its potential role in leukaemia.

  5. A Catalog of Genes Homozygously Deleted in Human Lung Cancer and the Candidacy of PTPRD as a Tumor Suppressor Gene

    Science.gov (United States)

    Kohno, Takashi; Otsuka, Ayaka; Girard, Luc; Sato, Masanori; Iwakawa, Reika; Ogiwara, Hideaki; Sanchez-Cespedes, Montse; Minna, John D.; Yokota, Jun

    2010-01-01

    A total of 176 genes homozygously deleted in human lung cancer were identified by DNA array-based whole genome scanning of 52 lung cancer cell lines and subsequent genomic PCR in 74 cell lines, including the 52 cell lines scanned. One or more exons of these genes were homozygously deleted in one (1%) to 20 (27%) cell lines. These genes included known tumor suppressor genes, e.g., CDKN2A/p16, RB1, and SMAD4, and candidate tumor suppressor genes whose hemizygous or homozygous deletions were reported in several types of human cancers, such as FHIT, KEAP1, and LRP1B/LRP-DIP. CDKN2A/p16 and p14ARF located in 9p21 were most frequently deleted (20/74, 27%). The PTPRD gene was most frequently deleted (8/74, 11%) among genes mapping to regions other than 9p21. Somatic mutations, including a nonsense mutation, of the PTPRD gene were detected in 8/74 (11%) of cell lines and 4/95 (4%) of surgical specimens of lung cancer. Reduced PTPRD expression was observed in the majority (>80%) of cell lines and surgical specimens of lung cancer. Therefore, PTPRD is a candidate tumor suppressor gene in lung cancer. Microarray-based expression profiling of 19 lung cancer cell lines also indicated that some of the 176 genes, such as KANK and ADAMTS1, are preferentially inactivated by epigenetic alterations. Genetic/epigenetic as well as functional studies of these 176 genes will increase our understanding of molecular mechanisms behind lung carcinogenesis. PMID:20073072

  6. Putative tumour-suppressor gene DAB2 is frequently down regulated by promoter hypermethylation in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Tong, Joanna H; Lo, Kwok W; To, Ka F; Ng, David C; Chau, Shuk L; So, Ken K; Leung, Patrick P; Lee, Tin L; Lung, Raymond W; Chan, Michael W; Chan, Anthony W

    2010-01-01

    Human Disabled-2 (DAB2), is a multi-function signalling molecule that it is frequently down-regulated in human cancers. We aimed to investigate the possible tumour suppressor effect of DAB2 in nasopharyngeal carcinoma (NPC). We studied the expression of DAB2 in NPC cell lines, xenografts and primary tumour samples. The status of promoter methylation was assessed by methylation specific PCR and bisulfite sequencing. The functional role of DAB2 in NPC was investigated by re-introducing DAB2 expression into NPC cell line C666-1. Decrease or absent of DAB2 transcript was observed in NPC cell lines and xenografts. Loss of DAB2 protein expression was seen in 72% (33/46) of primary NPC as demonstrated by immunohistochemistry. Aberrant DAB2 promoter methylation was detected in 65.2% (30/46) of primary NPC samples by methylation specific PCR. Treatment of the DAB2 negative NPC cell line C666-1 with 5-aza-2'-deoxycytidine resulted in restoration of DAB2 expression in a dose-dependent manner. Overexpression of DAB2 in NPC cell line C666-1 resulted in reduced growth rate and 35% reduction in anchorage-dependent colony formation, and inhibition of serum-induced c-Fos expression compared to vector-transfected controls. Over expression of DAB2 resulted in alterations of multiple pathways as demonstrated by expression profiling and functional network analysis, which confirmed the role of DAB2 as an adaptor molecule involved in multiple receptor-mediated signalling pathways. We report the frequent down regulation of DAB2 in NPC and the promoter hypermethylation contributes to the loss of expression of DAB2. This is the first study demonstrating frequent DAB2 promoter hypermethylation in human cancer. Our functional studies support the putative tumour suppressor effect of DAB2 in NPC cells

  7. The Ras effector RASSF2 is a novel tumor-suppressor gene in human colorectal cancer.

    Science.gov (United States)

    Akino, Kimishige; Toyota, Minoru; Suzuki, Hiromu; Mita, Hiroaki; Sasaki, Yasushi; Ohe-Toyota, Mutsumi; Issa, Jean-Pierre J; Hinoda, Yuji; Imai, Kohzoh; Tokino, Takashi

    2005-07-01

    Activation of Ras signaling is a hallmark of colorectal cancer (CRC), but the roles of negative regulators of Ras are not fully understood. Our aim was to address that question by surveying genetic and epigenetic alterations of Ras-Ras effector genes in CRC cells. The expression and methylation status of 6 RASSF family genes were examined using RT-PCR and bisulfite PCR in CRC cell lines and in primary CRCs and colorectal adenomas. Colony formation assays and flow cytometry were used to assess the tumor suppressor activities of RASSF1 and RASSF2. Immunofluorescence microscopy was used to determine the effect of altered RASSF2 expression on cell morphology. Mutations of K- ras , BRAF, and p53 were identified using single-strand conformation analysis and direct sequencing. Aberrant methylation and histone deacetylation of RASSF2 was associated with the gene's silencing in CRC. The activities of RASSF2, which were distinct from those of RASSF1, included induction of morphologic changes and apoptosis; moreover, its ability to prevent cell transformation suggests that RASSF2 acts as a tumor suppressor in CRC. Primary CRCs that showed K- ras /BRAF mutations also frequently showed RASSF2 methylation, and inactivation of RASSF2 enhanced K- ras -induced oncogenic transformation. RASSF2 methylation was also frequently identified in colorectal adenomas. RASSF2 is a novel tumor suppressor gene that regulates Ras signaling and plays a pivotal role in the early stages of colorectal tumorigenesis.

  8. A genome-wide shRNA screen identifies GAS1 as a novel melanoma metastasis suppressor gene.

    Science.gov (United States)

    Gobeil, Stephane; Zhu, Xiaochun; Doillon, Charles J; Green, Michael R

    2008-11-01

    Metastasis suppressor genes inhibit one or more steps required for metastasis without affecting primary tumor formation. Due to the complexity of the metastatic process, the development of experimental approaches for identifying genes involved in metastasis prevention has been challenging. Here we describe a genome-wide RNAi screening strategy to identify candidate metastasis suppressor genes. Following expression in weakly metastatic B16-F0 mouse melanoma cells, shRNAs were selected based upon enhanced satellite colony formation in a three-dimensional cell culture system and confirmed in a mouse experimental metastasis assay. Using this approach we discovered 22 genes whose knockdown increased metastasis without affecting primary tumor growth. We focused on one of these genes, Gas1 (Growth arrest-specific 1), because we found that it was substantially down-regulated in highly metastatic B16-F10 melanoma cells, which contributed to the high metastatic potential of this mouse cell line. We further demonstrated that Gas1 has all the expected properties of a melanoma tumor suppressor including: suppression of metastasis in a spontaneous metastasis assay, promotion of apoptosis following dissemination of cells to secondary sites, and frequent down-regulation in human melanoma metastasis-derived cell lines and metastatic tumor samples. Thus, we developed a genome-wide shRNA screening strategy that enables the discovery of new metastasis suppressor genes.

  9. Overexpression of the p53 tumor suppressor gene product in primary lung adenocarcinomas is associated with cigarette smoking

    NARCIS (Netherlands)

    Westra, W. H.; Offerhaus, G. J.; Goodman, S. N.; Slebos, R. J.; Polak, M.; Baas, I. O.; Rodenhuis, S.; Hruban, R. H.

    1993-01-01

    Mutations in the p53 tumor suppressor gene are frequently observed in primary lung adenocarcinomas, suggesting that these mutations are critical events in the malignant transformation of airway cells. These mutations are often associated with stabilization of the p53 gene product, resulting in the

  10. Molecular biology III - Oncogenes and tumor suppressor genes

    International Nuclear Information System (INIS)

    Giaccia, Amato J.

    1996-01-01

    Purpose: The purpose of this course is to introduce to radiation oncologists the basic concepts of tumorigenesis, building on the information that will be presented in the first and second part of this series of lectures. Objective: Our objective is to increase the current understanding of radiation oncologists with the process of tumorigenesis, especially focusing on genes that are altered in many tumor types that are potential candidates for novel molecular strategies. As strategies to treat cancer of cancer are becoming more sophisticated, it will be important for both the practitioner and academician to develop a basic understanding of the function of cancer 'genes'. This will be the third in a series of refresher courses that are meant to address recent advances in Cancer Biology in a way that both clinicians without previous knowledge of molecular biology or experienced researchers will find interesting. The lecture will begin with a basic overview of tumorigenesis; methods of detecting chromosome/DNA alterations, approaches used to isolate oncogenes and tumor suppressor genes, and their role in cell killing by apoptosis. Special attention will be given to oncogenes and tumor suppressor genes that are modulated by ionizing radiation and the tumor microenvironment. We will relate the biology of oncogenes and tumor suppressor genes to basic aspects of radiation biology that would be important in clinical practice. Finally, we will review recent studies on the prognostic significance of p53 mutations and apoptosis in tumor specimens. The main point of this lecture is to relate both researcher and clinician what are the therapeutic ramifications of oncogene and tumor suppressor gene mutations found in human neoptasia

  11. Expression of the tumor suppressor genes NF2, 4.1B, and TSLC1 in canine meningiomas.

    Science.gov (United States)

    Dickinson, P J; Surace, E I; Cambell, M; Higgins, R J; Leutenegger, C M; Bollen, A W; LeCouteur, R A; Gutmann, D H

    2009-09-01

    Meningiomas are common primary brain tumors in dogs; however, little is known about the molecular genetic mechanisms involved in their tumorigenesis. Several tumor suppressor genes have been implicated in meningioma pathogenesis in humans, including the neurofibromatosis 2 (NF2), protein 4.1B (4.1 B), and tumor suppressor in lung cancer-1 (TSLC1) genes. We investigated the expression of these tumor suppressor genes in a series of spontaneous canine meningiomas using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) (NF2; n = 25) and western blotting (NF2/merlin, 4.1B, TSLC1; n = 30). Decreased expression of 4.1B and TSLC1 expression on western blotting was seen in 6/30 (20%) and in 15/30 (50%) tumors, respectively, with 18/30 (60%) of meningiomas having decreased or absent expression of one or both proteins. NF2 gene expression assessed by western blotting and RT-PCR varied considerably between individual tumors. Complete loss of NF2 protein on western blotting was not seen, unlike 4.1B and TSLC1. Incidence of TSLC1 abnormalities was similar to that seen in human meningiomas, while perturbation of NF2 and 4.1B appeared to be less common than reported for human tumors. No association was observed between tumor grade, subtype, or location and tumor suppressor gene expression based on western blot or RT-PCR. These results suggest that loss of these tumor suppressor genes is a frequent occurrence in canine meningiomas and may be an early event in tumorigenesis in some cases. In addition, it is likely that other, as yet unidentified, genes play an important role in canine meningioma formation and growth.

  12. RET is a potential tumor suppressor gene in colorectal cancer

    Science.gov (United States)

    Luo, Yanxin; Tsuchiya, Karen D.; Park, Dong Il; Fausel, Rebecca; Kanngurn, Samornmas; Welcsh, Piri; Dzieciatkowski, Slavomir; Wang, Jianping; Grady, William M.

    2012-01-01

    Cancer arises as the consequence of mutations and epigenetic alterations that activate oncogenes and inactivate tumor suppressor genes. Through a genome-wide screen for methylated genes in colon neoplasms, we identified aberrantly methylated RET in colorectal cancer. RET, a transmembrane receptor tyrosine kinase and a receptor for the GDNF-family ligands, was one of the first oncogenes to be identified and has been shown to be an oncogene in thyroid cancer and pheochromocytoma. However, unexpectedly, we found RET is methylated in 27% of colon adenomas and in 63% of colorectal cancers, and now provide evidence that RET has tumor suppressor activity in colon cancer. The aberrant methylation of RET correlates with decreased RET expression, whereas the restoration of RET in colorectal cancer cell lines results in apoptosis. Furthermore, in support of a tumor suppressor function of RET, mutant RET has also been found in primary colorectal cancer. We now show that these mutations inactivate RET, which is consistent with RET being a tumor suppressor gene in the colon. These findings suggest that the aberrant methylation of RET and the mutational inactivation of RET promote colorectal cancer formation and that RET can serve as a tumor suppressor gene in the colon. Moreover, the increased frequency of methylated RET in colon cancers compared to adenomas suggests RET inactivation is involved in the progression of colon adenomas to cancer. PMID:22751117

  13. Expression of the p16{sup INK4a} tumor suppressor gene in rodent lung tumors

    Energy Technology Data Exchange (ETDEWEB)

    Swafford, D.S.; Tesfaigzi, J.; Belinsky, S.A.

    1995-12-01

    Aberrations on the short arm of chromosome 9 are among the earliest genetic changes in human cancer. p16{sup INK4a} is a candidate tumor suppressor gene that lies within human 9p21, a chromosome region associated with frequent loss of heterozygosity in human lung tumors. The p16{sup INK4a} protein functions as an inhibitor of cyclin D{sub 1}-dependent kinases that phosphorylate the retinoblastoma (Rb) tumor suppressor gene product enabling cell-cycle progression. Thus, overexpression of cyclin D{sub 1}, mutation of cyclin-dependent kinase genes, or loss of p16{sup INK4a} function, can all result in functional inactivation of Rb. Inactivation of Rb by mutation or deletion can result in an increase in p16{sup INK4a} transcription, suggesting that an increased p16{sup INK4a} expression in a tumor cell signals dysfunction of the pathway. The p16{sup (INK4a)} gene, unlike some tumor suppressor genes, is rarely inactivated by mutation. Instead, the expression of this gene is suppressed in some human cancers by hypermethylation of the CpG island within the first exon or by homozygous deletion: 686. Chromosome losses have been observed at 9p21 syntenic loci in tumors of the mouse and rat, two species often used as animal models for pulmonary carcinogenesis. Expression of p16{sup INK4a} is lost in some mouse tumor cell lines, often due to homozygous deletion. These observations indicate that p16{sup INK4a} dysfunction may play a role in the development of neoplasia in rodents as well as humans. The purpose of the current investigation was to define the extent to which p16{sup INK4a} dysfunction contributes to the development of rodent lung tumors and to determine the mechanism of inactivation of the gene. There is no evidence to suggest a loss of function of the p16{sup INK4a} tumor suppressor gene in these primary murine lung tumors by mutation, deletion, or methylation.

  14. The effect of age at exposure on the inactivating mechanisms and relative contributions of key tumor suppressor genes in radiation-induced mouse T-cell lymphomas

    Energy Technology Data Exchange (ETDEWEB)

    Sunaoshi, Masaaki [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); Amasaki, Yoshiko; Hirano-Sakairi, Shinobu; Blyth, Benjamin J. [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Morioka, Takamitsu [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kaminishi, Mutsumi [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shang, Yi [Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Nishimura, Mayumi; Shimada, Yoshiya [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tachibana, Akira [Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); and others

    2015-09-15

    Highlights: • T-cell lymphoma incidence, latency and weight did not change with age at exposure. • Lymphomas had frequent loss of heterozygosity on chromosomes 4, 11 and 19. • These lesions targeted the Cdkn2a, Ikaros and Pten tumor suppressor genes. • Age at exposure may influence which tumor suppressor genes are lost in each tumor. • The mechanisms of tumor suppressor gene loss were different at each locus. - Abstract: Children are considered more sensitive to radiation-induced cancer than adults, yet any differences in genomic alterations associated with age-at-exposure and their underlying mechanisms remain unclear. We assessed genome-wide DNA copy number and mutation of key tumor suppressor genes in T-cell lymphomas arising after weekly irradiation of female B6C3F1 mice with 1.2 Gy X-rays for 4 consecutive weeks starting during infancy (1 week old), adolescence (4 weeks old) or as young adults (8 weeks old). Although T-cell lymphoma incidence was similar, loss of heterozygosity at Cdkn2a on chromosome 4 and at Ikaros on chromosome 11 was more frequent in the two older groups, while loss at the Pten locus on chromosome 19 was more frequent in the infant-irradiated group. Cdkn2a and Ikaros mutation/loss was a common feature of the young adult-irradiation group, with Ikaros frequently (50%) incurring multiple independent hits (including deletions and mutations) or suffering a single hit predicted to result in a dominant negative protein (such as those lacking exon 4, an isoform we have designated Ik12, which lacks two DNA binding zinc-finger domains). Conversely, Pten mutations were more frequent after early irradiation (60%) than after young adult-irradiation (30%). Homozygous Pten mutations occurred without DNA copy number change after irradiation starting in infancy, suggesting duplication of the mutated allele by chromosome mis-segregation or mitotic recombination. Our findings demonstrate that while deletions on chromosomes 4 and 11 affecting Cdkn2

  15. Unexpected functional similarities between gatekeeper tumour suppressor genes and proto-oncogenes revealed by systems biology.

    Science.gov (United States)

    Zhao, Yongzhong; Epstein, Richard J

    2011-05-01

    Familial tumor suppressor genes comprise two subgroups: caretaker genes (CTs) that repair DNA, and gatekeeper genes (GKs) that trigger cell death. Since GKs may also induce cell cycle delay and thus enhance cell survival by facilitating DNA repair, we hypothesized that the prosurvival phenotype of GKs could be selected during cancer progression, and we used a multivariable systems biology approach to test this. We performed multidimensional data analysis, non-negative matrix factorization and logistic regression to compare the features of GKs with those of their putative antagonists, the proto-oncogenes (POs), as well as with control groups of CTs and functionally unrelated congenital heart disease genes (HDs). GKs and POs closely resemble each other, but not CTs or HDs, in terms of gene structure (Pexpression level and breadth (Pimplied suggest a common functional attribute that is strongly negatively selected-that is, a shared phenotype that enhances cell survival. The counterintuitive finding of similar evolutionary pressures affecting GKs and POs raises an intriguing possibility: namely, that cancer microevolution is accelerated by an epistatic cascade in which upstream suppressor gene defects subvert the normal bifunctionality of wild-type GKs by constitutively shifting the phenotype away from apoptosis towards survival. If correct, this interpretation would explain the hitherto unexplained phenomenon of frequent wild-type GK (for example, p53) overexpression in tumors.

  16. Tumor suppressors: enhancers or suppressors of regeneration?

    Science.gov (United States)

    Pomerantz, Jason H.; Blau, Helen M.

    2013-01-01

    Tumor suppressors are so named because cancers occur in their absence, but these genes also have important functions in development, metabolism and tissue homeostasis. Here, we discuss known and potential functions of tumor suppressor genes during tissue regeneration, focusing on the evolutionarily conserved tumor suppressors pRb1, p53, Pten and Hippo. We propose that their activity is essential for tissue regeneration. This is in contrast to suggestions that tumor suppression is a trade-off for regenerative capacity. We also hypothesize that certain aspects of tumor suppressor pathways inhibit regenerative processes in mammals, and that transient targeted modification of these pathways could be fruitfully exploited to enhance processes that are important to regenerative medicine. PMID:23715544

  17. Alterations in tumour suppressor gene p53 in human gliomas from ...

    Indian Academy of Sciences (India)

    Unknown

    Alterations in the tumour suppressor p53 gene are among the most common defects seen in a variety of human cancers. ..... rangement of the EGF receptor gene in primary human brain tumors ... the INK4A gene in superficial bladder tumors.

  18. Tumor-suppressor genes that escape from X-inactivation contribute to cancer sex bias.

    Science.gov (United States)

    Dunford, Andrew; Weinstock, David M; Savova, Virginia; Schumacher, Steven E; Cleary, John P; Yoda, Akinori; Sullivan, Timothy J; Hess, Julian M; Gimelbrant, Alexander A; Beroukhim, Rameen; Lawrence, Michael S; Getz, Gad; Lane, Andrew A

    2017-01-01

    There is a striking and unexplained male predominance across many cancer types. A subset of X-chromosome genes can escape X-inactivation, which would protect females from complete functional loss by a single mutation. To identify putative 'escape from X-inactivation tumor-suppressor' (EXITS) genes, we examined somatic alterations from >4,100 cancers across 21 tumor types for sex bias. Six of 783 non-pseudoautosomal region (PAR) X-chromosome genes (ATRX, CNKSR2, DDX3X, KDM5C, KDM6A, and MAGEC3) harbored loss-of-function mutations more frequently in males (based on a false discovery rate < 0.1), in comparison to zero of 18,055 autosomal and PAR genes (Fisher's exact P < 0.0001). Male-biased mutations in genes that escape X-inactivation were observed in combined analysis across many cancers and in several individual tumor types, suggesting a generalized phenomenon. We conclude that biallelic expression of EXITS genes in females explains a portion of the reduced cancer incidence in females as compared to males across a variety of tumor types.

  19. Transgelin gene is frequently downregulated by promoter DNA hypermethylation in breast cancer.

    Science.gov (United States)

    Sayar, Nilufer; Karahan, Gurbet; Konu, Ozlen; Bozkurt, Betul; Bozdogan, Onder; Yulug, Isik G

    2015-01-01

    CpG hypermethylation in gene promoters is a frequent mechanism of tumor suppressor gene silencing in various types of cancers. It usually occurs at early steps of cancer progression and can be detected easily, giving rise to development of promising biomarkers for both detection and progression of cancer, including breast cancer. 5-aza-2'-deoxycytidine (AZA) is a DNA demethylating and anti-cancer agent resulting in induction of genes suppressed via DNA hypermethylation. Using microarray expression profiling of AZA- or DMSO-treated breast cancer and non-tumorigenic breast (NTB) cells, we identified for the first time TAGLN gene as a target of DNA hypermethylation in breast cancer. TAGLN expression was significantly and frequently downregulated via promoter DNA hypermethylation in breast cancer cells compared to NTB cells, and also in 13/21 (61.9 %) of breast tumors compared to matched normal tissues. Analyses of public microarray methylation data showed that TAGLN was also hypermethylated in 63.02 % of tumors compared to normal tissues; relapse-free survival of patients was worse with higher TAGLN methylation; and methylation levels could discriminate between tumors and healthy tissues with 83.14 % sensitivity and 100 % specificity. Additionally, qRT-PCR and immunohistochemistry experiments showed that TAGLN expression was significantly downregulated in two more independent sets of breast tumors compared to normal tissues and was lower in tumors with poor prognosis. Colony formation was increased in TAGLN silenced NTB cells, while decreased in overexpressing BC cells. TAGLN gene is frequently downregulated by DNA hypermethylation, and TAGLN promoter methylation profiles could serve as a future diagnostic biomarker, with possible clinical impact regarding the prognosis in breast cancer.

  20. Identification and Functional Analysis of Gene Regulatory Sequences Interacting with Colorectal Tumor Suppressors

    DEFF Research Database (Denmark)

    Dahlgaard, Katja; Troelsen, Jesper

    2018-01-01

    Several tumor suppressors possess gene regulatory activity. Here, we describe how promoter and promoter/enhancer reporter assays can be used to characterize a colorectal tumor suppressor proteins’ gene regulatory activity of possible target genes. In the first part, a bioinformatic approach...... of the quick and efficient In-Fusion cloning method, and how to carry out transient transfections of Caco-2 colon cancer cells with the produced luciferase reporter plasmids using polyethyleneimine (PEI). A plan describing how to set up and carry out the luciferase expression assay is presented. The luciferase...... to identify relevant gene regulatory regions of potential target genes is presented. In the second part, it is demonstrated how to prepare and carry out the functional assay. We explain how to clone the bioinformatically identified gene regulatory regions into luciferase reporter plasmids by the use...

  1. A study on tumor suppressor genes mutations associated with different pathological colorectal lesions

    International Nuclear Information System (INIS)

    Matar, S.N.A.

    2011-01-01

    Colorectal cancer (CRC) is the second leading cause of cancer-related death in the Western world. In Egypt; there is an increasing incidence of the disease, especially among patients ≤40 years age. While CRC have been reported in low incidence rate in developing countries, it is the third most common tumor in male and the fifth common tumor in females in Egypt. Early diagnosis and surgical interference guarantee long survival of most CRC patients. Early diagnosis is impeded by the disease onset at young age and imprecise symptoms at the initial stages of the disease. As in most solid tumors, the malignant transformation of colonic epithelial cells is to arise through a multistep process during which they acquire genetic changes involving the activation of proto-oncogenes and the loss of tumor suppressor genes. Recently, a candidate tumor suppressor gene, KLF6, which is mapped to chromosome 10p, was found to be frequently mutated in a number of cancers. There are some evidences suggesting that the disruption of the functional activity of KLF6 gene products may be one of the early events in tumor genesis of the colon. The main objective of the present study was to detect mutational changes of KLF6 tumor suppressor gene and to study the loss of heterozygosity (LOH) markers at chromosome 10p15 (KLF6 locus) in colorectal lesions and colorectal cancer in Egyptian patients. The patients included in this study were 83 presented with different indications for colonoscopic examination. Selecting patients with colorectal pre-cancerous lesions or colorectal cancer was done according to the results of tissue biopsy from lesion and adjacent normal. The patients were classified into three main groups; (G I) Cancerous group, (G II) polyps group including patients with adenomatous polyps (AP), familial adenomatous polyps (FAP) and hyperplastic polyps (HP) and (G III) Inflammatory Bowel Diseases (IBD) including patients with ulcerative colitis (UC) and Crohn's disease (CD

  2. ETS transcription factors control transcription of EZH2 and epigenetic silencing of the tumor suppressor gene Nkx3.1 in prostate cancer.

    Directory of Open Access Journals (Sweden)

    Paolo Kunderfranco

    2010-05-01

    Full Text Available ETS transcription factors regulate important signaling pathways involved in cell differentiation and development in many tissues and have emerged as important players in prostate cancer. However, the biological impact of ETS factors in prostate tumorigenesis is still debated.We performed an analysis of the ETS gene family using microarray data and real-time PCR in normal and tumor tissues along with functional studies in normal and cancer cell lines to understand the impact in prostate tumorigenesis and identify key targets of these transcription factors. We found frequent dysregulation of ETS genes with oncogenic (i.e., ERG and ESE1 and tumor suppressor (i.e., ESE3 properties in prostate tumors compared to normal prostate. Tumor subgroups (i.e., ERG(high, ESE1(high, ESE3(low and NoETS tumors were identified on the basis of their ETS expression status and showed distinct transcriptional and biological features. ERG(high and ESE3(low tumors had the most robust gene signatures with both distinct and overlapping features. Integrating genomic data with functional studies in multiple cell lines, we demonstrated that ERG and ESE3 controlled in opposite direction transcription of the Polycomb Group protein EZH2, a key gene in development, differentiation, stem cell biology and tumorigenesis. We further demonstrated that the prostate-specific tumor suppressor gene Nkx3.1 was controlled by ERG and ESE3 both directly and through induction of EZH2.These findings provide new insights into the role of the ETS transcriptional network in prostate tumorigenesis and uncover previously unrecognized links between aberrant expression of ETS factors, deregulation of epigenetic effectors and silencing of tumor suppressor genes. The link between aberrant ETS activity and epigenetic gene silencing may be relevant for the clinical management of prostate cancer and design of new therapeutic strategies.

  3. Alterations of tumor suppressor genes (Rb, p16, p27 and p53) and an increased FDG uptake in lung cancer

    International Nuclear Information System (INIS)

    Sasaki, Masayuki; Sugio, Kenji; Kuwabara, Yasuo

    2003-01-01

    The FDG uptake in lung cancer is considered to reflect the degree of malignancy, while alterations of some tumor suppressor genes are considered to be related to the malignant biological behavior of tumors. The aim of this study is to examine the relationship between FDG-PET and alterations in the tumor suppression genes of lung cancer. We examined 28 patients with primary lung cancer who underwent FDG-PET before surgery consisting of 17 patients with adenocarcinoma, 10 with squamous cell carcinoma and 1 with large cell carcinoma. The FDG-PET findings were evaluated based on the standardized uptake value (SUV). Alterations in the tumor suppressor genes, Rb, p16, p27 and p53, were evaluated immunohistochemically. The FDG uptake in lung cancer with alteration in each tumor suppressor gene tended to be higher than in those genes without alterations, although the differences were not significant. In 15 tumors with alterations in either tumor suppressor genes, the FDG uptake was 6.83±3.21. On the other hand, the mean FDG uptake was 1.95 in 2 tumors without alterations in any genes. The difference in the FDG uptake between the 2 groups was statistically significant (p<0.001). In conclusion, the presence of abnormalities in the tumor suppressor genes, which results in an accelerated cell proliferation, is thus considered to increase the FDG uptake in lung cancer. (author)

  4. Off and back-on again: a tumor suppressor's tale.

    Science.gov (United States)

    Acosta, Jonuelle; Wang, Walter; Feldser, David M

    2018-06-01

    Tumor suppressor genes play critical roles orchestrating anti-cancer programs that are both context dependent and mechanistically diverse. Beyond canonical tumor suppressive programs that control cell division, cell death, and genome stability, unexpected tumor suppressor gene activities that regulate metabolism, immune surveillance, the epigenetic landscape, and others have recently emerged. This diversity underscores the important roles these genes play in maintaining cellular homeostasis to suppress cancer initiation and progression, but also highlights a tremendous challenge in discerning precise context-specific programs of tumor suppression controlled by a given tumor suppressor. Fortunately, the rapid sophistication of genetically engineered mouse models of cancer has begun to shed light on these context-dependent tumor suppressor activities. By using techniques that not only toggle "off" tumor suppressor genes in nascent tumors, but also facilitate the timely restoration of gene function "back-on again" in disease specific contexts, precise mechanisms of tumor suppression can be revealed in an unbiased manner. This review discusses the development and implementation of genetic systems designed to toggle tumor suppressor genes off and back-on again and their potential to uncover the tumor suppressor's tale.

  5. Down-regulation of SFRP1 as a putative tumor suppressor gene can contribute to human hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Huang, Jian; Zhang, Yun-Li; Teng, Xiao-Mei; Lin, Yun; Zheng, Da-Li; Yang, Peng-Yuan; Han, Ze-Guang

    2007-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cancers in the world. SFRP1 (the secreted frizzled-related protein 1), a putative tumor suppressor gene mapped onto chromosome 8p12-p11.1, the frequent loss of heterozygosity (LOH) region in human HCC, encodes a Wingless-type (Wnt) signaling antagonist and is frequently inactivated by promoter methylation in many human cancers. However, whether the down-regulation of SFRP1 can contribute to hepatocarcinogenesis still remains unclear. We investigated the expression of SFRP1 through real time RT-PCR and immunohistochemistry staining. The cell growth and colony formation were observed as the overexpression and knockdown of SFRP1. The DNA methylation status within SFRP1 promoter was analyzed through methylation-specific PCR or bisulphate-treated DNA sequencing assays. Loss of heterozygosity was here detected with microsatellite markers. SFRP1 was significantly down-regulated in 76.1% (35/46) HCC specimens at mRNA level and in 30% (30/100) HCCs indicated by immunohistochemistry staining, as compared to adjacent non-cancerous livers. The overexpression of SFRP1 can significantly inhibit the cell growth and colony formation of YY-8103, SMMC7721, and Hep3B cells. The RNA interference against the constitutional SFRP1 in the offspring SMMC7721 cells, which were stably transfected by ectopic SFRP1, can markedly promote cell growth of these cells. LOH of both microsatellite markers D8S532 and D8SAC016868 flanking the gene locus was found in 13% (6 of 46 HCCs) and 6.5% (3 of 46 HCCs) of the informative cases, respectively, where 5 of 8 HCC specimens with LOH showed the down-regulation of SFRP1. DNA hypermethylation within SFRP1 promoter was identified in two of three HCC specimens without SFRP1 expression. Moreover, the DNA methylation of SFRP1 promoter was significantly reduced, along with the re-expression of the gene, in those HCC cell lines, Bel7404, QGY7701, and MHCC-H, as treated by DAC. Our data suggested that the

  6. Analysis of a Novel 17q25 Cell Cycle Gene Homolog: Is it a Breast Tumor Suppressor Gene?

    National Research Council Canada - National Science Library

    Kalikin, Linda

    2000-01-01

    ... of these molecular reagents into successful tools for the medical management of breast cancer. We hypothesize that a 350 kb region on 17q25 detected by our allelic imbalance studies harbors a novel breast tumor suppressor gene...

  7. SFRP Tumour Suppressor Genes Are Potential Plasma-Based Epigenetic Biomarkers for Malignant Pleural Mesothelioma

    Directory of Open Access Journals (Sweden)

    Yuen Yee Cheng

    2017-01-01

    Full Text Available Malignant pleural mesothelioma (MPM is associated with asbestos exposure. Asbestos can induce chronic inflammation which in turn can lead to silencing of tumour suppressor genes. Wnt signaling pathway can be affected by chronic inflammation and is aberrantly activated in many cancers including colon and MPM. SFRP genes are antagonists of Wnt pathway, and SFRPs are potential tumour suppressors in colon, gastric, breast, ovarian, and lung cancers and mesothelioma. This study investigated the expression and DNA methylation of SFRP genes in MPM cells lines with and without demethylation treatment. Sixty-six patient FFPE samples were analysed and have showed methylation of SFRP2 (56% and SFRP5 (70% in MPM. SFRP2 and SFRP5 tumour-suppressive activity in eleven MPM lines was confirmed, and long-term asbestos exposure led to reduced expression of the SFRP1 and SFRP2 genes in the mesothelium (MeT-5A via epigenetic alterations. Finally, DNA methylation of SFRPs is detectable in MPM patient plasma samples, with methylated SFRP2 and SFRP5 showing a tendency towards greater abundance in patients. These data suggested that SFRP genes have tumour-suppresive activity in MPM and that methylated DNA from SFRP gene promoters has the potential to serve as a biomarker for MPM patient plasma.

  8. Frequent loss of heterozygosity and altered expression of the candidate tumor suppressor gene 'FAT' in human astrocytic tumors

    International Nuclear Information System (INIS)

    Chosdol, Kunzang; Misra, Anjan; Puri, Sachin; Srivastava, Tapasya; Chattopadhyay, Parthaprasad; Sarkar, Chitra; Mahapatra, Ashok K; Sinha, Subrata

    2009-01-01

    We had earlier used the comparison of RAPD (Random Amplification of Polymorphic DNA) DNA fingerprinting profiles of tumor and corresponding normal DNA to identify genetic alterations in primary human glial tumors. This has the advantage that DNA fingerprinting identifies the genetic alterations in a manner not biased for locus. In this study we used RAPD-PCR to identify novel genomic alterations in the astrocytic tumors of WHO grade II (Low Grade Diffuse Astrocytoma) and WHO Grade IV (Glioblastoma Multiforme). Loss of heterozygosity (LOH) of the altered region was studied by microsatellite and Single Nucleotide Polymorphism (SNP) markers. Expression study of the gene identified at the altered locus was done by semi-quantitative reverse-transcriptase-PCR (RT-PCR). Bands consistently altered in the RAPD profile of tumor DNA in a significant proportion of tumors were identified. One such 500 bp band, that was absent in the RAPD profile of 33% (4/12) of the grade II astrocytic tumors, was selected for further study. Its sequence corresponded with a region of FAT, a putative tumor suppressor gene initially identified in Drosophila. Fifty percent of a set of 40 tumors, both grade II and IV, were shown to have Loss of Heterozygosity (LOH) at this locus by microsatellite (intragenic) and by SNP markers. Semi-quantitative RT-PCR showed low FAT mRNA levels in a major subset of tumors. These results point to a role of the FAT in astrocytic tumorigenesis and demonstrate the use of RAPD analysis in identifying specific alterations in astrocytic tumors

  9. Molecular studies on the function of tumor suppressor gene in gastrointestinal cancer

    International Nuclear Information System (INIS)

    Kim, You Cheoul

    1993-01-01

    Cancer of stomach, colon and liver are a group of the most common cancer in Korea. However, results with current therapeutic modalities are still unsatisfactory. The intensive efforts have been made to understand basic pathogenesis and to find better therapeutic tools for the treatment of this miserable disease. We studies the alteration of tumor suppressor gene in various Gastrointestinal cancer in Korea. Results showed that genetic alteration of Rb gene was in 83% of colorectal cancer. Our results suggest that genetic alteration of Rb gene is crucially involved in the tumorigenesis of colorectum in Korea. (Author)

  10. p53 tumor suppressor gene: significance in neoplasia - a review

    International Nuclear Information System (INIS)

    Alam, J.M.

    2000-01-01

    p53 is a tumor suppressor gene located on chromosome 17p13.1. Its function includes cell cycle control and apoptosis. Loss of p53 function, either due to decreased level or genetic transformation, is associated with loss of cell cycle control, decrease, apoptosis and genomic modification, such mutation of p53 gene is now assessed and the indicator of neoplasia of cancer of several organs and cell types, p53 has demonstrated to have critical role in defining various progressive stages of neoplasia, therapeutic strategies and clinical application. The present review briefly describes function of p53 in addition to its diagnostic and prognostic significance in detecting several types of neoplasia. (author)

  11. The epigenetic modifier PRDM5 functions as a tumor suppressor through modulating WNT/β-catenin signaling and is frequently silenced in multiple tumors.

    Directory of Open Access Journals (Sweden)

    Xing-sheng Shu

    Full Text Available BACKGROUND: PRDM (PRDI-BF1 and RIZ domain containing proteins are zinc finger proteins involved in multiple cellular regulations by acting as epigenetic modifiers. We studied a recently identified PRDM member PRDM5 for its epigenetic abnormality and tumor suppressive functions in multiple tumorigeneses. METHODOLOGY/PRINCIPAL FINDINGS: Semi-quantitative RT-PCR showed that PRDM5 was broadly expressed in human normal tissues, but frequently silenced or downregulated in multiple carcinoma cell lines due to promoter CpG methylation, including 80% (4/5 nasopharyngeal, 44% (8/18 esophageal, 76% (13/17 gastric, 50% (2/4 cervical, and 25% (3/12 hepatocellular carcinoma cell lines, but not in any immortalized normal epithelial cell lines. PRDM5 expression could be restored by 5-aza-2'-deoxycytidine demethylation treatment in silenced cell lines. PRDM5 methylation was frequently detected by methylation-specific PCR (MSP in multiple primary tumors, including 93% (43/46 nasopharyngeal, 58% (25/43 esophageal, 88% (37/42 gastric and 63% (29/46 hepatocellular tumors. PRDM5 was further found a stress-responsive gene, but its response was impaired when the promoter was methylated. Ectopic PRDM5 expression significantly inhibited tumor cell clonogenicity, accompanied by the inhibition of TCF/β-catenin-dependent transcription and downregulation of CDK4, TWIST1 and MDM2 oncogenes, while knocking down of PRDM5 expression lead to increased cell proliferation. ChIP assay showed that PRDM5 bound to its target gene promoters and suppressed their transcription. An inverse correlation between the expression of PRDM5 and activated β-catenin was also observed in cell lines. CONCLUSIONS/SIGNIFICANCE: PRDM5 functions as a tumor suppressor at least partially through antagonizing aberrant WNT/β-catenin signaling and oncogene expression. Frequent epigenetic silencing of PRDM5 is involved in multiple tumorigeneses, which could serve as a tumor biomarker.

  12. Tumor Suppressor Genes within Common Fragile Sites Are Active Players in the DNA Damage Response.

    Directory of Open Access Journals (Sweden)

    Idit Hazan

    2016-12-01

    Full Text Available The role of common fragile sites (CFSs in cancer remains controversial. Two main views dominate the discussion: one suggests that CFS loci are hotspots of genomic instability leading to inactivation of genes encoded within them, while the other view proposes that CFSs are functional units and that loss of the encoded genes confers selective pressure, leading to cancer development. The latter view is supported by emerging evidence showing that expression of a given CFS is associated with genome integrity and that inactivation of CFS-resident tumor suppressor genes leads to dysregulation of the DNA damage response (DDR and increased genomic instability. These two viewpoints of CFS function are not mutually exclusive but rather coexist; when breaks at CFSs are not repaired accurately, this can lead to deletions by which cells acquire growth advantage because of loss of tumor suppressor activities. Here, we review recent advances linking some CFS gene products with the DDR, genomic instability, and carcinogenesis and discuss how their inactivation might represent a selective advantage for cancer cells.

  13. P53 tumor suppressor gene and protein expression is altered in cell lines derived from spontaneous and alpha-radiation-induced canine lung tumors

    International Nuclear Information System (INIS)

    Tierney, L.A.; Johnson, N.F.; Lechner, J.F.

    1994-01-01

    Mutations in the p53 tumor suppressor gene are the most frequently occurring gene alterations in malignant human cancers, including lung cancer. In lung cancer, common point mutations within conserved exons of the p53 gene result in a stabilized form of mutant protein which is detectable in most cases by immunohistochemistry. In addition to point mutations, allelic loss, rearrangements, and deletions of the p53 gene have also been detected in both human and rodent tumors. It has been suggested that for at least some epithelial neoplasms, the loss of expression of wild-type p53 protein may be more important for malignant transformation than the acquisition of activating mutations. Mechanisms responsible for the loss of expression of wild-type protein include gene deletion or rearrangement, nonsense or stop mutations, mutations within introns or upstream regulatory regions of the gene, and accelerated rates of degradation of the protein by DNA viral oncoproteins

  14. The tumor suppressor Rb and its related Rbl2 genes are regulated by Utx histone demethylase

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Minoru; Ishimura, Akihiko; Yoshida, Masakazu [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan); Suzuki, Yutaka; Sugano, Sumio [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Chiba (Japan); Suzuki, Takeshi, E-mail: suzuki-t@staff.kanazawa-u.ac.jp [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan)

    2010-08-20

    Research highlights: {yields} Utx increases expression of Rb and Rbl2 genes through its demethylase activity. {yields} Utx changes histone H3 methylation on the Rb and Rbl2 promoters. {yields} Utx induces decreased cell proliferation of mammalian primary cells. -- Abstract: Utx is a candidate tumor suppressor gene that encodes histone H3 lysine 27 (H3K27) demethylase. In this study, we found that ectopic expression of Utx enhanced the expression of retinoblastoma tumor suppressor gene Rb and its related gene Rbl2. This activation was dependent on the demethylase activity of Utx, and was suggested to contribute to the decreased cell proliferation induced by Utx. A chromatin immunoprecipitation assay showed that over-expressed Utx was associated with the promoter regions of Rb and Rbl2 resulting in the removal of repressive H3K27 tri-methylation and the increase in active H3K4 tri-methylation. Furthermore, siRNA-mediated knockdown of Utx revealed the recruitment of endogenous Utx protein on the promoters of Rb and Rbl2 genes. These results indicate that Rb and Rbl2 are downstream target genes of Utx and may play important roles in Utx-mediated cell growth control.

  15. Tumor suppressor WWOX and p53 alterations and drug resistance in glioblastomas

    Directory of Open Access Journals (Sweden)

    Ming-Fu eChiang

    2013-03-01

    Full Text Available Tumor suppressor p53 are frequently mutated in glioblastomas (GBMs and appears to contribute, in part, to resistance to temozolomide and therapeutic drugs. WW domain-containing oxidoreductase WWOX (FOR or WOX1 is a proapoptotic protein and is considered as a tumor suppressor. Loss of WWOX gene expression is frequently seen in malignant cancer cells due to promoter hypermethylation, genetic alterations, and translational blockade. Intriguingly, ectopic expression of wild type WWOX preferentially induces apoptosis in human glioblastoma cells harboring mutant p53. WWOX is known to physically bind and stabilize wild type p53. Here, we provide an overview for the updated knowledge in p53 and WWOX, and postulate a potential scenarios that wild type and mutant p53, or isoforms, modulate the apoptotic function of WWOX. We propose that triggering WWOX activation by therapeutic drugs under p53 functional deficiency is needed to overcome TMZ resistance and induce GBM cell death.

  16. Role of natural antisense transcripts pertaining to tumor suppressor genes in human carcinomas

    International Nuclear Information System (INIS)

    Pelicci, G.; Pierotti, M.

    2009-01-01

    Overlapping transcripts in opposite orientations can potentially form perfect sense-antisense duplex RNA. Recently, several studies have revealed the extent of natural antisense transcripts (NATs) and their role in important biological phenomena also in higher organisms. In order to test the hypothesis that the function of NATs in man might represent an essential element in the regulation of gene expression, especially at transcriptional level, in this study we planned to look for, systematically examine, and characterize NATs belonging in the human genome to the tumour suppressor class of genes, so to identify physiological (and potentially pathological) modulators in this gene class

  17. No evidence for promoter region methylation of the succinate dehydrogenase and fumarate hydratase tumour suppressor genes in breast cancer

    Directory of Open Access Journals (Sweden)

    Dobrovic Alexander

    2009-09-01

    Full Text Available Abstract Background Succinate dehydrogenase (SDH and fumarate hydratase (FH are tricarboxylic acid (TCA cycle enzymes that are also known to act as tumour suppressor genes. Increased succinate or fumarate levels as a consequence of SDH and FH deficiency inhibit hypoxia inducible factor-1α (HIF-1α prolyl hydroxylases leading to sustained HIF-1α expression in tumours. Since HIF-1α is frequently expressed in breast carcinomas, DNA methylation at the promoter regions of the SDHA, SDHB, SDHC and SDHD and FH genes was evaluated as a possible mechanism in silencing of SDH and FH expression in breast carcinomas. Findings No DNA methylation was identified in the promoter regions of the SDHA, SDHB, SDHC, SDHD and FH genes in 72 breast carcinomas and 10 breast cancer cell lines using methylation-sensitive high resolution melting which detects both homogeneous and heterogeneous methylation. Conclusion These results show that inactivation via DNA methylation of the promoter CpG islands of SDH and FH is unlikely to play a major role in sporadic breast carcinomas.

  18. Sleep quality and methylation status of selected tumor suppressor genes among nurses and midwives.

    Science.gov (United States)

    Bukowska-Damska, Agnieszka; Reszka, Edyta; Kaluzny, Pawel; Wieczorek, Edyta; Przybek, Monika; Zienolddiny, Shanbeh; Peplonska, Beata

    2018-01-01

    Chronic sleep restriction may affect metabolism, hormone secretion patterns and inflammatory responses. Limited reports suggest also epigenetic effects, such as changes in DNA methylation profiles. The study aims to assess the potential association between poor sleep quality or sleep duration and the levels of 5-methylcytosine in the promoter regions of selected tumor suppressor genes. A cross-sectional study was conducted on 710 nurses and midwives aged 40-60 years. Data from interviews regarding sleep habits and potential confounders were used. The methylation status of tumor suppressor genes was determined via qMSP reactions using DNA samples derived from leucocytes. No significant findings were observed in the total study population or in the two subgroups of women stratified by the current system of work. A borderline significance association was observed between a shorter duration of sleep and an increased methylation level in CDKN2A among day working nurses and midwives. Further studies are warranted to explore this under-investigated topic.

  19. A novel proapoptotic gene PANO encodes a post-translational modulator of the tumor suppressor p14ARF

    Energy Technology Data Exchange (ETDEWEB)

    Watari, Akihiro; Li, Yang; Higashiyama, Shinji; Yutsudo, Masuo, E-mail: yutsudo@biken.osaka-u.ac.jp

    2012-02-01

    The protein p14ARF is a known tumor suppressor protein controlling cell proliferation and survival, which mainly localizes in nucleoli. However, the regulatory mechanisms that govern its activity or expression remain unclear. Here, we report that a novel proapoptotic nucleolar protein, PANO, modulates the expression and activity of p14ARF in HeLa cells. Overexpression of PANO enhances the stability of p14ARF protein by protecting it from degradation, resulting in an increase in p14ARF expression levels. Overexpression of PANO also induces apoptosis under low serum conditions. This effect is dependent on the nucleolar localization of PANO and inhibited by knocking-down p14ARF. Alternatively, PANO siRNA treated cells exhibit a reduction in p14ARF protein levels. In addition, ectopic expression of PANO suppresses the tumorigenicity of HeLa cells in nude mice. These results indicate that PANO is a new apoptosis-inducing gene by modulating the tumor suppressor protein, p14ARF, and may itself be a new candidate tumor suppressor gene.

  20. An innovative strategy to clone positive modifier genes of defects caused by mtDNA mutations: MRPS18C as suppressor gene of m.3946G>A mutation in MT-ND1 gene.

    Science.gov (United States)

    Rodríguez-García, María Elena; Cotrina-Vinagre, Francisco Javier; Carnicero-Rodríguez, Patricia; Martínez-Azorín, Francisco

    2017-07-01

    We have developed a new functional complementation approach to clone modifier genes which overexpression is able to suppress the biochemical defects caused by mtDNA mutations (suppressor genes). This strategy consists in transferring human genes into respiratory chain-deficient fibroblasts, followed by a metabolic selection in a highly selective medium. We used a normalized expression cDNA library in an episomal vector (pREP4) to transfect the fibroblasts, and a medium with glutamine and devoid of any carbohydrate source to select metabolically. Growing the patient's fibroblasts in this selective medium, the deficient cells rapidly disappear unless they are rescued by the cDNA of a suppressor gene. The use of an episomal vector allows us to carry out several rounds of transfection/selection (cyclical phenotypic rescue) to enrich the rescue with true clones of suppressor genes. Using fibroblasts from a patient with epileptic encephalopathy with the m.3946G>A (p.E214K) mutation in the MT-ND1 gene, several candidate genes were identified and one of them was characterized functionally. Thus, overexpression of MRPS18C gene (that encode for bS18m protein) suppressed the molecular defects produced by this mtDNA mutation, recovering the complex I activity and reducing the ROS produced by this complex to normal levels. We suggest that modulation of bS18m expression may be an effective therapeutic strategy for the patients with this mutation.

  1. Complementation of non-tumorigenicity of HPV18-positive cervical carcinoma cells involves differential mRNA expression of cellular genes including potential tumor suppressor genes on chromosome 11q13.

    Science.gov (United States)

    Kehrmann, Angela; Truong, Ha; Repenning, Antje; Boger, Regina; Klein-Hitpass, Ludger; Pascheberg, Ulrich; Beckmann, Alf; Opalka, Bertram; Kleine-Lowinski, Kerstin

    2013-01-01

    The fusion between human tumorigenic cells and normal human diploid fibroblasts results in non-tumorigenic hybrid cells, suggesting a dominant role for tumor suppressor genes in the generated hybrid cells. After long-term cultivation in vitro, tumorigenic segregants may arise. The loss of tumor suppressor genes on chromosome 11q13 has been postulated to be involved in the induction of the tumorigenic phenotype of human papillomavirus (HPV)18-positive cervical carcinoma cells and their derived tumorigenic hybrid cells after subcutaneous injection in immunocompromised mice. The aim of this study was the identification of novel cellular genes that may contribute to the suppression of the tumorigenic phenotype of non-tumorigenic hybrid cells in vivo. We used cDNA microarray technology to identify differentially expressed cellular genes in tumorigenic HPV18-positive hybrid and parental HeLa cells compared to non-tumorigenic HPV18-positive hybrid cells. We detected several as yet unknown cellular genes that play a role in cell differentiation, cell cycle progression, cell-cell communication, metastasis formation, angiogenesis, antigen presentation, and immune response. Apart from the known differentially expressed genes on 11q13 (e.g., phosphofurin acidic cluster sorting protein 1 (PACS1) and FOS ligand 1 (FOSL1 or Fra-1)), we detected novel differentially expressed cellular genes located within the tumor suppressor gene region (e.g., EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2) and leucine rich repeat containing 32 (LRRC32) (also known as glycoprotein-A repetitions predominant (GARP)) that may have potential tumor suppressor functions in this model system of non-tumorigenic and tumorigenic HeLa x fibroblast hybrid cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. LARG at chromosome 11q23 has functional characteristics of a tumor suppressor in human breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Danny C.T.; Rudduck, Christina; Chin, Koei; Kuo, Wen-Lin; Lie, Daniel K.H.; Chua, Constance L.M.; Wong, Chow Yin; Hong, Ga Sze; Gray, Joe; Lee, Ann S.G.

    2008-05-06

    Deletion of 11q23-q24 is frequent in a diverse variety of malignancies, including breast and colorectal carcinoma, implicating the presence of a tumor suppressor gene at that chromosomal region. We show here that LARG, from 11q23, has functional characteristics of a tumor suppressor. We examined a 6-Mb region on 11q23 by high-resolution deletion mapping, utilizing both loss of heterozygosity (LOH) analysis and microarray comparative genomic hybridization (CGH). LARG (also called ARHGEF12), identified from the analyzed region, was underexpressed in 34% of primary breast carcinomas and 80% of breast cancer cell lines including the MCF-7 line. Multiplex ligation-dependent probe amplification on 30 primary breast cancers and six breast cancer cell lines showed that LARG had the highest frequency of deletion compared to the BCSC-1 and TSLC1 genes, two known candidate tumor suppressor genes from 11q. In vitro analysis of breast cancer cell lines that underexpress LARG showed that LARG could be reactivated by trichostatin A, a histone deacetylase inhibitor, but not by 5-Aza-2{prime}-deoxycytidine, a demethylating agent. Bisulfite sequencing and quantitative high-throughput analysis of DNA methylation confirmed the lack of CpG island methylation in LARG in breast cancer. Restoration of LARG expression in MCF-7 cells by stable transfection resulted in reduced proliferation and colony formation, suggesting that LARG has functional characteristics of a tumor suppressor gene.

  3. Generation of two modified mouse alleles of the Hic1 tumor suppressor gene

    Czech Academy of Sciences Publication Activity Database

    Pospíchalová, Vendula; Turečková, Jolana; Fafílek, Bohumil; Vojtěchová, Martina; Krausová, Michaela; Lukáš, Jan; Šloncová, Eva; Takacova, S.; Divoký, V.; Leprince, D.; Plachý, Jiří; Kořínek, Vladimír

    2011-01-01

    Roč. 49, č. 3 (2011), s. 142-151 ISSN 1526-954X R&D Projects: GA ČR(CZ) GA204/07/1567; GA ČR(CZ) GD204/09/H058 Institutional research plan: CEZ:AV0Z50520514 Keywords : Hypermethylated In Cancer 1 * Hic1 tumor suppressor * gene targeting Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.527, year: 2011

  4. Tumor suppressor microRNAs are downregulated in myelodysplastic syndrome with spliceosome mutations

    DEFF Research Database (Denmark)

    Aslan, Derya; Garde, Christian; Nygaard, Mette Katrine

    2016-01-01

    Spliceosome mutations are frequently observed in patients with myelodysplastic syndromes (MDS). However, it is largely unknown how these mutations contribute to the disease. MicroRNAs (miRNAs) are small noncoding RNAs, which have been implicated in most human cancers due to their role in post...... the most downregulated miRNAs were several tumor-suppressor miRNAs, including several let-7 family members, miR-423, and miR-103a. Finally, we observed that the predicted targets of the most downregulated miRNAs were involved in apoptosis, hematopoiesis, and acute myeloid leukemia among other cancer......- and metabolic pathways. Our data indicate that spliceosome mutations may play an important role in MDS pathophysiology by affecting the expression of tumor suppressor miRNA genes involved in the development and progression of MDS....

  5. Multi-gene epigenetic silencing of tumor suppressor genes in T-cell lymphoma cells; delayed expression of the p16 protein upon reversal of the silencing

    DEFF Research Database (Denmark)

    Nagasawa, T; Zhang, Q; Raghunath, P N

    2006-01-01

    To understand better T-cell lymphomagenesis, we examined promoter CpG methylation and mRNA expression of closely related genes encoding p16, p15, and p14 tumor suppressor genes in cultured malignant T-cells that were derived from cutaneous, adult type, and anaplastic lymphoma kinase (ALK)-express...

  6. Allelic loss of the short arm of chromosome 4 in neuroblastoma suggests a novel tumour suppressor gene locus

    NARCIS (Netherlands)

    Caron, H.; van Sluis, P.; Buschman, R.; Pereira do Tanque, R.; Maes, P.; Beks, L.; de Kraker, J.; Voûte, P. A.; Vergnaud, G.; Westerveld, A.; Slater, R.; Versteeg, R.

    1996-01-01

    Neuroblastoma is a childhood neural crest tumour, genetically characterized by frequent deletions of the short arm of chromosome 1 and amplification of N-myc. Here we report the first evidence for a neuroblastoma tumour suppressor locus on 4pter. Cytogenetically we demonstrated rearrangements of 4p

  7. Polymorphism of the p53 tumor suppressor gene is associated with susceptibility to uterine leiomyoma.

    Science.gov (United States)

    Denschlag, Dominik; Bettendorf, Herta; Watermann, Dirk; Keck, Christoph; Tempfer, Clemens; Pietrowski, Detlef

    2005-07-01

    To evaluate the association between the presence of uterine leiomyoma and two single nuclear polymorphisms of the p53 tumor suppressor and the angiopoietin-2 (ANGPT2) genes. Prospective case control study. Academic research institution. One hundred thirty-two women with clinically and surgically diagnosed uterine leiomyomas and 280 controls. Peripheral venous puncture. Genotyping was performed by polymerase chain reaction-based amplification of the Arg and Pro variants at codon 72 of the p53 gene and by restriction fragment length polymorphism analysis of the G/G and G/A alleles in exon 4 of the ANGPT2 gene. Comparing women with uterine leiomyomas and controls, no statistically significant difference with respect to allele frequency and genotype distribution were ascertained for the ANGPT2 polymorphism (P=.2 and P=.5, respectively). However, for the p53 tumor suppressor gene polymorphism, statistically significant differences in terms of a higher Pro allele frequency and a higher prevalence of the Pro/Pro genotype among women with uterine leiomyoma (32.0% vs. 16.0%, respectively, and 21.3% vs. 4.7%, respectively) were ascertained (P=.001, OR 1.74; 95% CI 1.24-2.45, P=.001; OR 3.84, 95% CI 1.81-8.14; respectively). Carriage of the p53 polymorphism at codon 72 predicts the susceptibility to leiomyoma in a Caucasian population and may contribute to the pathogenesis of uterine leiomyoma.

  8. Key tumor suppressor genes inactivated by "greater promoter" methylation and somatic mutations in head and neck cancer

    NARCIS (Netherlands)

    Guerrero-Preston, Rafael; Michailidi, Christina; Marchionni, Luigi; Pickering, Curtis R.; Frederick, Mitchell J.; Myers, Jeffrey N.; Yegnasubramanian, Srinivasan; Hadar, Tal; Noordhuis, Maartje G.; Zizkova, Veronika; Fertig, Elana; Agrawal, Nishant; Westra, William; Koch, Wayne; Califano, Joseph; Velculescu, Victor E.; Sidransky, David

    Tumor suppressor genes (TSGs) are commonly inactivated by somatic mutation and/or promoter methylation; yet, recent high-throughput genomic studies have not identified key TSGs inactivated by both mechanisms. We pursued an integrated molecular analysis based on methylation binding domain sequencing

  9. Grape seed proanthocyanidins reactivate silenced tumor suppressor genes in human skin cancer cells by targeting epigenetic regulators

    International Nuclear Information System (INIS)

    Vaid, Mudit; Prasad, Ram; Singh, Tripti; Jones, Virginia; Katiyar, Santosh K.

    2012-01-01

    Grape seed proanthocyanidins (GSPs) have been shown to have anti-skin carcinogenic effects in in vitro and in vivo models. However, the precise epigenetic molecular mechanisms remain unexplored. This study was designed to investigate whether GSPs reactivate silenced tumor suppressor genes following epigenetic modifications in skin cancer cells. For this purpose, A431 and SCC13 human squamous cell carcinoma cell lines were used as in vitro models. The effects of GSPs on DNA methylation, histone modifications and tumor suppressor gene expressions were studied in these cell lines using enzyme activity assays, western blotting, dot-blot analysis and real-time polymerase chain reaction (RT-PCR). We found that treatment of A431 and SCC13 cells with GSPs decreased the levels of: (i) global DNA methylation, (ii) 5-methylcytosine, (iii) DNA methyltransferase (DNMT) activity and (iv) messenger RNA (mRNA) and protein levels of DNMT1, DNMT3a and DNMT3b in these cells. Similar effects were noted when these cancer cells were treated identically with 5-aza-2′-deoxycytidine, an inhibitor of DNA methylation. GSPs decreased histone deacetylase activity, increased levels of acetylated lysines 9 and 14 on histone H3 (H3-Lys 9 and 14) and acetylated lysines 5, 12 and 16 on histone H4, and reduced the levels of methylated H3-Lys 9. Further, GSP treatment resulted in re-expression of the mRNA and proteins of silenced tumor suppressor genes, RASSF1A, p16 INK4a and Cip1/p21. Together, this study provides a new insight into the epigenetic mechanisms of GSPs and may have significant implications for epigenetic therapy in the treatment/prevention of skin cancers in humans. -- Highlights: ►Epigenetic modulations have been shown to have a role in cancer risk. ►Proanthocyanidins decrease the levels of DNA methylation and histone deacetylation. ►Proanthocyanidins inhibit histone deacetylase activity in skin cancer cells. ►Proanthocyanidins reactivate tumor suppressor genes in skin

  10. Presence of activating KRAS mutations correlates significantly with expression of tumour suppressor genes DCN and TPM1 in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Rems Miran

    2009-08-01

    Full Text Available Abstract Background Despite identification of the major genes and pathways involved in the development of colorectal cancer (CRC, it has become obvious that several steps in these pathways might be bypassed by other as yet unknown genetic events that lead towards CRC. Therefore we wanted to improve our understanding of the genetic mechanisms of CRC development. Methods We used microarrays to identify novel genes involved in the development of CRC. Real time PCR was used for mRNA expression as well as to search for chromosomal abnormalities within candidate genes. The correlation between the expression obtained by real time PCR and the presence of the KRAS mutation was investigated. Results We detected significant previously undescribed underexpression in CRC for genes SLC26A3, TPM1 and DCN, with a suggested tumour suppressor role. We also describe the correlation between TPM1 and DCN expression and the presence of KRAS mutations in CRC. When searching for chromosomal abnormalities, we found deletion of the TPM1 gene in one case of CRC, but no deletions of DCN and SLC26A3 were found. Conclusion Our study provides further evidence of decreased mRNA expression of three important tumour suppressor genes in cases of CRC, thus implicating them in the development of this type of cancer. Moreover, we found underexpression of the TPM1 gene in a case of CRCs without KRAS mutations, showing that TPM1 might serve as an alternative path of development of CRC. This downregulation could in some cases be mediated by deletion of the TPM1 gene. On the other hand, the correlation of DCN underexpression with the presence of KRAS mutations suggests that DCN expression is affected by the presence of activating KRAS mutations, lowering the amount of the important tumour suppressor protein decorin.

  11. DLC1 tumor suppressor gene inhibits migration and invasion of multiple myeloma cells through RhoA GTPase pathway

    Czech Academy of Sciences Publication Activity Database

    Ullmannová-Benson, Veronika; Guan, M.; Zhou, X. G.; Tripathi, V.; Yang, V.; Zimonjic, D. B.; Popescu, C.

    2009-01-01

    Roč. 23, č. 2 (2009), s. 383-390 ISSN 0887-6924 Institutional research plan: CEZ:AV0Z50200510 Keywords : multiple myeloma * tumor suppressor gene * promoter methylation Subject RIV: EC - Immunology Impact factor: 8.296, year: 2009

  12. P18 tumor suppressor gene and progression of oligodendrogliomas to anaplasia.

    Science.gov (United States)

    He, J; Hoang-Xuan, K; Marie, Y; Leuraud, P; Mokhtari, K; Kujas, M; Delattre, J Y; Sanson, M

    2000-09-26

    P18INK4C is a good candidate to be the tumor suppressor gene involved in oligodendrogliomas on 1p32. Loss of heterozygosity on 1p, mutation(s), homozygous deletion(s), and expression of p18 in 30 oligodendroglial tumors were investigated. Loss of heterozygosity on 1p was found in 15 tumors. A p18 mutation was found at an recurrence of an anaplastic oligodendroglioma, but not in the primary, low-grade tumor. No homozygous deletions were found and p18 was expressed in all cases. These results show that p18 alteration is involved in tumor progression in a subset of oligodendrogliomas.

  13. PCR-RFLP to Detect Codon 248 Mutation in Exon 7 of "p53" Tumor Suppressor Gene

    Science.gov (United States)

    Ouyang, Liming; Ge, Chongtao; Wu, Haizhen; Li, Suxia; Zhang, Huizhan

    2009-01-01

    Individual genome DNA was extracted fast from oral swab and followed up with PCR specific for codon 248 of "p53" tumor suppressor gene. "Msp"I restriction mapping showed the G-C mutation in codon 248, which closely relates to cancer susceptibility. Students learn the concepts, detection techniques, and research significance of point mutations or…

  14. RPS6KA2, a putative tumour suppressor gene at 6q27 in sporadic epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Bignone, P A; Lee, K Y; Liu, Y

    2007-01-01

    We had previously defined by allele loss studies a minimal region at 6q27 (between D6S264 and D6S297) to contain a putative tumour suppressor gene. The p90 ribosomal S6 kinase-3 gene (p90 Rsk-3, RPS6KA2) maps in this interval. It is a serine-threonine kinase that signals downstream of the mitogen...

  15. Evolution of the HIV-1 nef gene in HLA-B*57 Positive Elite Suppressors

    Directory of Open Access Journals (Sweden)

    Siliciano Robert F

    2010-11-01

    Full Text Available Abstract Elite controllers or suppressors (ES are HIV-1 infected patients who maintain viral loads of gag and nef in HLA-B*57 positive ES. We previously showed evolution in the gag gene of ES which surprisingly was mostly due to synonymous mutations rather than non-synonymous mutation in targeted CTL epitopes. This finding could be the result of structural constraints on Gag, and we therefore examined the less conserved nef gene. We found slow evolution of nef in plasma virus in some ES. This evolution is mostly due to synonymous mutations and occurs at a rate similar to that seen in the gag gene in the same patients. The results provide further evidence of ongoing viral replication in ES and suggest that the nef and gag genes in these patients respond similarly to selective pressure from the host.

  16. Gene trapping identifies a putative tumor suppressor and a new inducer of cell migration

    International Nuclear Information System (INIS)

    Guardiola-Serrano, Francisca; Haendeler, Judith; Lukosz, Margarete; Sturm, Karsten; Melchner, Harald von; Altschmied, Joachim

    2008-01-01

    Tumor necrosis factor alpha (TNFα) is a pleiotropic cytokine involved in apoptotic cell death, cellular proliferation, differentiation, inflammation, and tumorigenesis. In tumors it is secreted by tumor associated macrophages and can have both pro- and anti-tumorigenic effects. To identify genes regulated by TNFα, we performed a gene trap screen in the mammary carcinoma cell line MCF-7 and recovered 64 unique, TNFα-induced gene trap integration sites. Among these were the genes coding for the zinc finger protein ZC3H10 and for the transcription factor grainyhead-like 3 (GRHL3). In line with the dual effects of TNFα on tumorigenesis, we found that ZC3H10 inhibits anchorage independent growth in soft agar suggesting a tumor suppressor function, whereas GRHL3 strongly stimulated the migration of endothelial cells which is consistent with an angiogenic, pro-tumorigenic function

  17. Promoter hypermethylation contributes to frequent inactivation of a putative conditional tumor suppressor gene connective tissue growth factor in ovarian cancer.

    Science.gov (United States)

    Kikuchi, Ryoko; Tsuda, Hitoshi; Kanai, Yae; Kasamatsu, Takahiro; Sengoku, Kazuo; Hirohashi, Setsuo; Inazawa, Johji; Imoto, Issei

    2007-08-01

    Connective tissue growth factor (CTGF) is a secreted protein belonging to the CCN family, members of which are implicated in various biological processes. We identified a homozygous loss of CTGF (6q23.2) in the course of screening a panel of ovarian cancer cell lines for genomic copy number aberrations using in-house array-based comparative genomic hybridization. CTGF mRNA expression was observed in normal ovarian tissue and immortalized ovarian epithelial cells but was reduced in many ovarian cancer cell lines without its homozygous deletion (12 of 23 lines) and restored after treatment with 5-aza 2'-deoxycytidine. The methylation status around the CTGF CpG island correlated inversely with the expression, and a putative target region for methylation showed promoter activity. CTGF methylation was frequently observed in primary ovarian cancer tissues (39 of 66, 59%) and inversely correlated with CTGF mRNA expression. In an immunohistochemical analysis of primary ovarian cancers, CTGF protein expression was frequently reduced (84 of 103 cases, 82%). Ovarian cancer tended to lack CTGF expression more frequently in the earlier stages (stages I and II) than the advanced stages (stages III and IV). CTGF protein was also differentially expressed among histologic subtypes. Exogenous restoration of CTGF expression or treatment with recombinant CTGF inhibited the growth of ovarian cancer cells lacking its expression, whereas knockdown of endogenous CTGF accelerated growth of ovarian cancer cells with expression of this gene. These results suggest that epigenetic silencing by hypermethylation of the CTGF promoter leads to a loss of CTGF function, which may be a factor in the carcinogenesis of ovarian cancer in a stage-dependent and/or histologic subtype-dependent manner.

  18. ING Genes Work as Tumor Suppressor Genes in the Carcinogenesis of Head and Neck Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Xiaohan Li

    2011-01-01

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is the sixth most common cancer in the world. The evolution and progression of HNSCC are considered to result from multiple stepwise alterations of cellular and molecular pathways in squamous epithelium. Recently, inhibitor of growth gene (ING family consisting of five genes, ING1 to ING5, was identified as a new tumor suppressor gene family that was implicated in the downregulation of cell cycle and chromatin remodeling. In contrast, it has been shown that ING1 and ING2 play an oncogenic role in some cancers, this situation being similar to TGF-β. In HNSCC, the ING family has been reported to be downregulated, and ING translocation from the nucleus to the cytoplasm may be a critical event for carcinogenesis. In this paper, we describe our recent results and briefly summarize current knowledge regarding the biologic functions of ING in HNSCC.

  19. Epigenetic profiling of cutaneous T-cell lymphoma: promoter hypermethylation of multiple tumor suppressor genes including BCL7a, PTPRG, and p73.

    Science.gov (United States)

    van Doorn, Remco; Zoutman, Willem H; Dijkman, Remco; de Menezes, Renee X; Commandeur, Suzan; Mulder, Aat A; van der Velden, Pieter A; Vermeer, Maarten H; Willemze, Rein; Yan, Pearlly S; Huang, Tim H; Tensen, Cornelis P

    2005-06-10

    To analyze the occurrence of promoter hypermethylation in primary cutaneous T-cell lymphoma (CTCL) on a genome-wide scale, focusing on epigenetic alterations with pathogenetic significance. DNA isolated from biopsy specimens of 28 patients with CTCL, including aggressive CTCL entities (transformed mycosis fungoides and CD30-negative large T-cell lymphoma) and an indolent entity (CD30-positive large T-cell lymphoma), were investigated. For genome-wide DNA methylation screening, differential methylation hybridization using CpG island microarrays was applied, which allows simultaneous detection of the methylation status of 8640 CpG islands. Bisulfite sequence analysis was applied for confirmation and detection of hypermethylation of eight selected tumor suppressor genes. The DNA methylation patterns of CTCLs emerging from differential methylation hybridization analysis included 35 CpG islands hypermethylated in at least four of the 28 studied CTCL samples when compared with benign T-cell samples. Hypermethylation of the putative tumor suppressor genes BCL7a (in 48% of CTCL samples), PTPRG (27%), and thrombospondin 4 (52%) was confirmed and demonstrated to be associated with transcriptional downregulation. BCL7a was hypermethylated at a higher frequency in aggressive (64%) than in indolent (14%) CTCL entities. In addition, the promoters of the selected tumor suppressor genes p73 (48%), p16 (33%), CHFR (19%), p15 (10%), and TMS1 (10%) were hypermethylated in CTCL. Malignant T cells of patients with CTCL display widespread promoter hypermethylation associated with inactivation of several tumor suppressor genes involved in DNA repair, cell cycle, and apoptosis signaling pathways. In view of this, CTCL may be amenable to treatment with demethylating agents.

  20. The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development.

    Science.gov (United States)

    Ortega-Molina, Ana; Boss, Isaac W; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A; Gascoyne, Randy D; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M; Wendel, Hans-Guido

    2015-10-01

    The gene encoding the lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma and diffuse large B cell lymphoma; however, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center involution and impedes B cell differentiation and class switch recombination. Integrative genomic analyses indicate that KMT2D affects methylation of lysine 4 on histone H3 (H3K4) and expression of a set of genes, including those in the CD40, JAK-STAT, Toll-like receptor and B cell receptor signaling pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3 and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell-activating pathways.

  1. Tumor Suppressor Gene-Based Nanotherapy: From Test Tube to the Clinic

    Directory of Open Access Journals (Sweden)

    Manish Shanker

    2011-01-01

    Full Text Available Cancer is a major health problem in the world. Advances made in cancer therapy have improved the survival of patients in certain types of cancer. However, the overall five-year survival has not significantly improved in the majority of cancer types. Major challenges encountered in having effective cancer therapy are development of drug resistance by the tumor cells, nonspecific cytotoxicity, and inability to affect metastatic tumors by the chemodrugs. Overcoming these challenges requires development and testing of novel therapies. One attractive cancer therapeutic approach is cancer gene therapy. Several laboratories including the authors' laboratory have been investigating nonviral formulations for delivering therapeutic genes as a mode for effective cancer therapy. In this paper the authors will summarize their experience in the development and testing of a cationic lipid-based nanocarrier formulation and the results from their preclinical studies leading to a Phase I clinical trial for nonsmall cell lung cancer. Their nanocarrier formulation containing therapeutic genes such as tumor suppressor genes when administered intravenously effectively controls metastatic tumor growth. Additional Phase I clinical trials based on the results of their nanocarrier formulation have been initiated or proposed for treatment of cancer of the breast, ovary, pancreas, and metastatic melanoma, and will be discussed.

  2. Tumor suppressor gene-based nanotherapy: from test tube to the clinic.

    Science.gov (United States)

    Shanker, Manish; Jin, Jiankang; Branch, Cynthia D; Miyamoto, Shinya; Grimm, Elizabeth A; Roth, Jack A; Ramesh, Rajagopal

    2011-01-01

    Cancer is a major health problem in the world. Advances made in cancer therapy have improved the survival of patients in certain types of cancer. However, the overall five-year survival has not significantly improved in the majority of cancer types. Major challenges encountered in having effective cancer therapy are development of drug resistance by the tumor cells, nonspecific cytotoxicity, and inability to affect metastatic tumors by the chemodrugs. Overcoming these challenges requires development and testing of novel therapies. One attractive cancer therapeutic approach is cancer gene therapy. Several laboratories including the authors' laboratory have been investigating nonviral formulations for delivering therapeutic genes as a mode for effective cancer therapy. In this paper the authors will summarize their experience in the development and testing of a cationic lipid-based nanocarrier formulation and the results from their preclinical studies leading to a Phase I clinical trial for nonsmall cell lung cancer. Their nanocarrier formulation containing therapeutic genes such as tumor suppressor genes when administered intravenously effectively controls metastatic tumor growth. Additional Phase I clinical trials based on the results of their nanocarrier formulation have been initiated or proposed for treatment of cancer of the breast, ovary, pancreas, and metastatic melanoma, and will be discussed.

  3. Loss of Mitochondrial Tumor Suppressor Genes Expression Is Associated with Unfavorable Clinical Outcome in Head and Neck Squamous Cell Carcinoma: Data from Retrospective Study.

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    Ishrat Mahjabeen

    Full Text Available Mitochondrial genes play important roles in cellular energy metabolism, free radical generation, and apoptosis. Dysregulation of these genes have long been suspected to contribute to the generation of reactive oxygen species (ROS, increased proliferation and progression of cancer. A family of orthologues of yeast silent information regulator 3 (SIRT3, 4 (SIRT4 and mitochondrial tumor suppressor 1 (MTUS1 are important mitochondrial tumor suppressor genes which play an important role in the progression of multiple cancers. However, their role in the development of oxidative stress, enhanced proliferation and progression of head and neck squamous cell carcinoma (HNSCC has not yet been studied. In this study we aimed to test the association between reduced mitochondrial tumor suppressor genes' activities and enhancement in tissue oxidative stress and cell proliferation in HNSCC cases. The expression of mitochondrial tumor suppressor genes (SIRT3, SIRT4 and MTUS1, mitochondrial DNA repair gene (OGG1-2a and a proliferation marker (Ki-67 was studied in a study cohort of 120 HNSCC patients and controls with reverse transcriptase polymerase chain reaction (RT-PCR and real-time PCR (qPCR in order to determine the potential prognostic significance of these genes. A statistically significant downregulation of SIRT3 (p<0.001, SIRT4 (p<0.0001, MTUS1 (p<0.002 and OGG1 (p<0.0001 was observed in HNSCC compared to control samples. Ki-67 was also overexpressed (p<0.0001 in HNSCC versus control samples. Additionally, to explore gene-gene relationship, we observed a positive spearmen correlation between SIRT3 versus SIRT4 (r = 0.523***, p<0.0001, SIRT3 versus MTUS1 (r = 0.273***, p<0.001, SIRT3 versus OGG1-2a (r = 0.213*, p<0.03, SIRT4 versus OGG1 (r = 0.338***, p<0.0001 and MTUS1 versus OGG1-2a (r = 0.215*, p<0.03 in HNSCC cases. A negative spearman correlation was observed between OGG1 versus Ki-67 (r = -0.224**, p<0.01 and OGG1-2a versus Ki-67 (r = -0.224**, p<0

  4. Genome‐wide DNA methylation analysis identifies MEGF10 as a novel epigenetically repressed candidate tumor suppressor gene in neuroblastoma

    Science.gov (United States)

    Charlet, Jessica; Tomari, Ayumi; Dallosso, Anthony R.; Szemes, Marianna; Kaselova, Martina; Curry, Thomas J.; Almutairi, Bader; Etchevers, Heather C.; McConville, Carmel; Malik, Karim T. A.

    2016-01-01

    Neuroblastoma is a childhood cancer in which many children still have poor outcomes, emphasising the need to better understand its pathogenesis. Despite recent genome‐wide mutation analyses, many primary neuroblastomas do not contain recognizable driver mutations, implicating alternate molecular pathologies such as epigenetic alterations. To discover genes that become epigenetically deregulated during neuroblastoma tumorigenesis, we took the novel approach of comparing neuroblastomas to neural crest precursor cells, using genome‐wide DNA methylation analysis. We identified 93 genes that were significantly differentially methylated of which 26 (28%) were hypermethylated and 67 (72%) were hypomethylated. Concentrating on hypermethylated genes to identify candidate tumor suppressor loci, we found the cell engulfment and adhesion factor gene MEGF10 to be epigenetically repressed by DNA hypermethylation or by H3K27/K9 methylation in neuroblastoma cell lines. MEGF10 showed significantly down‐regulated expression in neuroblastoma tumor samples; furthermore patients with the lowest‐expressing tumors had reduced relapse‐free survival. Our functional studies showed that knock‐down of MEGF10 expression in neuroblastoma cell lines promoted cell growth, consistent with MEGF10 acting as a clinically relevant, epigenetically deregulated neuroblastoma tumor suppressor gene. © 2016 The Authors. Molecular Carcinogenesis Published by Wiley Periodicals, Inc. PMID:27862318

  5. Cholesterol and phytosterols differentially regulate the expression of caveolin 1 and a downstream prostate cell growth-suppressor gene

    Science.gov (United States)

    Ifere, Godwin O.; Equan, Anita; Gordon, Kereen; Nagappan, Peri; Igietseme, Joseph U.; Ananaba, Godwin A.

    2010-01-01

    Background The purpose of our study was to show the distinction between the apoptotic and anti-proliferative signaling of phytosterols and cholesterol enrichment in prostate cancer cell lines, mediated by the differential transcription of caveolin-1, and N-myc downstream regulated gene1 (NDRG1), a pro-apoptotic androgen-regulated tumor suppressor. Methods PC-3 and DU145 cells were treated with sterols (cholesterol and phytosterols) for 72 h, followed by trypan blue dye exclusion measurement of necrosis and cell growth measured with a Coulter counter. Sterol induction of cell growth-suppressor gene expression was evaluated by mRNA transcription using RT-PCR, while cell cycle analysis was performed by FACS analysis. Altered expression of Ndrg1 protein was confirmed by Western blot analysis. Apoptosis was evaluated by real time RT-PCR amplification of P53, Bcl-2 gene and its related pro- and anti-apoptotic family members. Results Physiological doses (16 µM) of cholesterol and phytosterols were not cytotoxic in these cells. Cholesterol enrichment promoted cell growth (Pphytosterols significantly induced growth-suppression (Pphytosterols decreased mitotic subpopulations. We demonstrated for the first time that cholesterols concertedly attenuated the expression of caveolin-1(cav-1) and NDRG1 genes in both prostate cancer cell lines. Phytosterols had the opposite effect by inducing overexpression of cav-1, a known mediator of androgen-dependent signals that presumably control cell growth or apoptosis. Conclusions Cholesterol and phytosterol treatment differentially regulated the growth of prostate cancer cells and the expression of p53 and cav-1, a gene that regulates androgen-regulated signals. These sterols also differentially regulated cell cycle arrest, downstream pro-apoptotic androgen-regulated tumor-suppressor, NDRG1 suggesting that cav-1 may mediate pro-apoptotic NDRG1 signals. Elucidation of the mechanism for sterol modulation of growth and apoptosis signaling

  6. Polymorphisms rs12998 and rs5780218 in KiSS1 Suppressor Metastasis Gene in Mexican Patients with Breast Cancer

    Directory of Open Access Journals (Sweden)

    Edhit Guadalupe Cruz Quevedo

    2015-01-01

    Full Text Available Aims. KiSS1 is a metastasis suppressor gene associated with inhibition of cellular chemotaxis and invasion attenuating the metastasis in melanoma and breast cancer cell lines. Along the KiSS-1 gene at least 294 SNPs have been described; however the association of these polymorphisms as genetic markers for metastasis in breast cancer studies has not been investigated. Here we describe two simple PCR-RFLPs protocols to identify the rs5780218 (9DelT and the rs12998 (E20K KiSS1 polymorphisms and the allelic, genotypic, and haplotypic frequencies in Mexican general population (GP and patients with benign breast disease (BBD or breast cancer (BC. Results. The rs5780218 polymorphism was individually associated with breast cancer (P=0.0332 and the rs12998 polymorphism shows statistically significant differences when GP versus case (BC and BBD groups were compared (P<0.0001. The H1 Haplotype (G/- occurred more frequently in BC group (0.4256 whereas H2 haplotype (G/T was the most prevalent in BBD group (0.4674. Conclusions. Our data indicated that the rs5780218 polymorphism individually confers susceptibility for development of breast cancer in Mexican population and a possible role as a genetic marker in breast cancer metastasis for H1 haplotype (Wt/variant in KiSS1 gene must be analyzed in other populations.

  7. DMBT1 is frequently downregulated in well-differentiated gastric carcinoma but more frequently upregulated across various gastric cancer types

    DEFF Research Database (Denmark)

    Conde, Ana R; Martins, Ana P; Brito, Miguel

    2007-01-01

    in cell differentiation and protection and has been proposed as a candidate tumour suppressor for brain and epithelial cancer. One study reported a loss of DMBT1 expression in 12.5% (5/40) of gastric cancer samples. Here, we examined in more detail DMBT1 protein and mRNA expression in 78 primary gastric...... preferentially take place in well-differentiated gastric carcinoma. However, an upregulation of DMBT1 expression is more frequently found across all gastric cancer types.......Well-differentiated gastric carcinomas are considered to represent a distinct entity emerging via specific molecular changes different from those found in other gastric carcinoma types. The gene deleted in malignant brain tumours 1 (DMBT1) at 10q25.3-q26.1 codes for a protein presumably involved...

  8. Towards the Identification of New Genes Involved in ABA-Dependent Abiotic Stresses Using Arabidopsis Suppressor Mutants of abh1 Hypersensitivity to ABA during Seed Germination

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    Iwona Szarejko

    2013-06-01

    Full Text Available Abscisic acid plays a pivotal role in the abiotic stress response in plants. Although great progress has been achieved explaining the complexity of the stress and ABA signaling cascade, there are still many questions to answer. Mutants are a valuable tool in the identification of new genes or new alleles of already known genes and in elucidating their role in signaling pathways. We applied a suppressor mutation approach in order to find new components of ABA and abiotic stress signaling in Arabidopsis. Using the abh1 (ABA hypersensitive 1 insertional mutant as a parental line for EMS mutagenesis, we selected several mutants with suppressed hypersensitivity to ABA during seed germination. Here, we present the response to ABA and a wide range of abiotic stresses during the seed germination and young seedling development of two suppressor mutants—soa2 (suppressor of abh1 hypersensitivity to ABA 2 and soa3 (suppressor of abh1 hypersensitivity to ABA 3. Generally, both mutants displayed a suppression of the hypersensitivity of abh1 to ABA, NaCl and mannitol during germination. Both mutants showed a higher level of tolerance than Columbia-0 (Col-0—the parental line of abh1 in high concentrations of glucose. Additionally, soa2 exhibited better root growth than Col-0 in the presence of high ABA concentrations. soa2 and soa3 were drought tolerant and both had about 50% fewer stomata per mm2 than the wild-type but the same number as their parental line—abh1. Taking into account that suppressor mutants had the same genetic background as their parental line—abh1, it was necessary to backcross abh1 with Landsberg erecta four times for the map-based cloning approach. Mapping populations, derived from the cross of abh1 in the Landsberg erecta background with each suppressor mutant, were created. Map based cloning in order to identify the suppressor genes is in progress.

  9. Generation and characterization of mice carrying a conditional allele of the Wwox tumor suppressor gene.

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    John H Ludes-Meyers

    2009-11-01

    Full Text Available WWOX, the gene that spans the second most common human chromosomal fragile site, FRA16D, is inactivated in multiple human cancers and behaves as a suppressor of tumor growth. Since we are interested in understanding WWOX function in both normal and cancer tissues we generated mice harboring a conditional Wwox allele by flanking Exon 1 of the Wwox gene with LoxP sites. Wwox knockout (KO mice were developed by breeding with transgenic mice carrying the Cre-recombinase gene under the control of the adenovirus EIIA promoter. We found that Wwox KO mice suffered from severe metabolic defect(s resulting in growth retardation and all mice died by 3 wk of age. All Wwox KO mice displayed significant hypocapnia suggesting a state of metabolic acidosis. This finding and the known high expression of Wwox in kidney tubules suggest a role for Wwox in acid/base balance. Importantly, Wwox KO mice displayed histopathological and hematological signs of impaired hematopoiesis, leukopenia, and splenic atrophy. Impaired hematopoiesis can also be a contributing factor to metabolic acidosis and death. Hypoglycemia and hypocalcemia was also observed affecting the KO mice. In addition, bone metabolic defects were evident in Wwox KO mice. Bones were smaller and thinner having reduced bone volume as a consequence of a defect in mineralization. No evidence of spontaneous neoplasia was observed in Wwox KO mice. We have generated a new mouse model to inactivate the Wwox tumor suppressor gene conditionally. This will greatly facilitate the functional analysis of Wwox in adult mice and will allow investigating neoplastic transformation in specific target tissues.

  10. Frequent epigenetic inactivation of Wnt antagonist genes in breast cancer

    Science.gov (United States)

    Suzuki, H; Toyota, M; Caraway, H; Gabrielson, E; Ohmura, T; Fujikane, T; Nishikawa, N; Sogabe, Y; Nojima, M; Sonoda, T; Mori, M; Hirata, K; Imai, K; Shinomura, Y; Baylin, S B; Tokino, T

    2008-01-01

    Although mutation of APC or CTNNB1 (β-catenin) is rare in breast cancer, activation of Wnt signalling is nonetheless thought to play an important role in breast tumorigenesis, and epigenetic silencing of Wnt antagonist genes, including the secreted frizzled-related protein (SFRP) and Dickkopf (DKK) families, has been observed in various tumours. In breast cancer, frequent methylation and silencing of SFRP1 was recently documented; however, altered expression of other Wnt antagonist genes is largely unknown. In the present study, we found frequent methylation of SFRP family genes in breast cancer cell lines (SFRP1, 7 out of 11, 64%; SFRP2, 11 out of 11, 100%; SFRP5, 10 out of 11, 91%) and primary breast tumours (SFRP1, 31 out of 78, 40%; SFRP2, 60 out of 78, 77%; SFRP5, 55 out of 78, 71%). We also observed methylation of DKK1, although less frequently, in cell lines (3 out of 11, 27%) and primary tumours (15 out of 78, 19%). Breast cancer cell lines express various Wnt ligands, and overexpression of SFRPs inhibited cancer cell growth. In addition, overexpression of a β-catenin mutant and depletion of SFRP1 using small interfering RNA synergistically upregulated transcriptional activity of T-cell factor/lymphocyte enhancer factor. Our results confirm the frequent methylation and silencing of Wnt antagonist genes in breast cancer, and suggest that their loss of function contributes to activation of Wnt signalling in breast carcinogenesis. PMID:18283316

  11. Alternative polyadenylation of tumor suppressor genes in small intestinal neuroendocrine tumors.

    Science.gov (United States)

    Rehfeld, Anders; Plass, Mireya; Døssing, Kristina; Knigge, Ulrich; Kjær, Andreas; Krogh, Anders; Friis-Hansen, Lennart

    2014-01-01

    The tumorigenesis of small intestinal neuroendocrine tumors (SI-NETs) is poorly understood. Recent studies have associated alternative polyadenylation (APA) with proliferation, cell transformation, and cancer. Polyadenylation is the process in which the pre-messenger RNA is cleaved at a polyA site and a polyA tail is added. Genes with two or more polyA sites can undergo APA. This produces two or more distinct mRNA isoforms with different 3' untranslated regions. Additionally, APA can also produce mRNAs containing different 3'-terminal coding regions. Therefore, APA alters both the repertoire and the expression level of proteins. Here, we used high-throughput sequencing data to map polyA sites and characterize polyadenylation genome-wide in three SI-NETs and a reference sample. In the tumors, 16 genes showed significant changes of APA pattern, which lead to either the 3' truncation of mRNA coding regions or 3' untranslated regions. Among these, 11 genes had been previously associated with cancer, with 4 genes being known tumor suppressors: DCC, PDZD2, MAGI1, and DACT2. We validated the APA in three out of three cases with quantitative real-time-PCR. Our findings suggest that changes of APA pattern in these 16 genes could be involved in the tumorigenesis of SI-NETs. Furthermore, they also point to APA as a new target for both diagnostic and treatment of SI-NETs. The identified genes with APA specific to the SI-NETs could be further tested as diagnostic markers and drug targets for disease prevention and treatment.

  12. Genetic and biochemical evidence that haploinsufficiency of the Nf1 tumor suppressor gene modulates melanocyte and mast cell fates in vivo.

    Science.gov (United States)

    Ingram, D A; Yang, F C; Travers, J B; Wenning, M J; Hiatt, K; New, S; Hood, A; Shannon, K; Williams, D A; Clapp, D W

    2000-01-03

    Neurofibromatosis type 1 (NF1) is a common autosomal-dominant disorder characterized by cutaneous neurofibromas infiltrated with large numbers of mast cells, melanocyte hyperplasia, and a predisposition to develop malignant neoplasms. NF1 encodes a GTPase activating protein (GAP) for Ras. Consistent with Knudson's "two hit" model of tumor suppressor genes, leukemias and malignant solid tumors in NF1 patients frequently demonstrate somatic loss of the normal NF1 allele. However, the phenotypic and biochemical consequences of heterozygous inactivation of Nf1 are largely unknown. Recently neurofibromin, the protein encoded by NF1, was shown to negatively regulate Ras activity in Nf1-/- murine myeloid hematopoietic cells in vitro through the c-kit receptor tyrosine kinase (dominant white spotting, W). Since the W and Nf1 locus appear to function along a common developmental pathway, we generated mice with mutations at both loci to examine potential interactions in vivo. Here, we show that haploinsufficiency at Nf1 perturbs cell fates in mast cells in vivo, and partially rescues coat color and mast cell defects in W(41) mice. Haploinsufficiency at Nf1 also increased mast cell proliferation, survival, and colony formation in response to Steel factor, the ligand for c-kit. Furthermore, haploinsufficiency was associated with enhanced Ras-mitogen-activated protein kinase activity, a major downstream effector of Ras, via wild-type and mutant (W(41)) c-kit receptors. These observations identify a novel interaction between c-kit and neurofibromin in vivo, and offer experimental evidence that haploinsufficiency of Nf1 alters both cellular and biochemical phenotypes in two cell lineages that are affected in individuals with NF1. Collectively, these data support the emerging concept that heterozygous inactivation of tumor suppressor genes may have profound biological effects in multiple cell types.

  13. Relationship of ultrasonic shear wave velocity with oncogene and tumor suppressor gene expression in primary liver cancer lesions as well as angiogenesis factor contents

    Directory of Open Access Journals (Sweden)

    Xing Yin1

    2017-06-01

    Full Text Available Objective: To discuss the relationship of ultrasonic shear wave velocity (SWV with oncogene and tumor suppressor gene expression in primary liver cancer lesions as well as angiogenesis factor contents. Methods: 100 patients with primary liver cancer who underwent surgical treatment in our hospital between March 2014 and September 2016 were collected as observation group, and 50 healthy subjects who received physical examination in our hospital during the same period were collected as normal control group. The ultrasonic SWV levels of two groups of subjects were measured before the operation, and the observation groups were further divided into high SWV group and low SWV group, 50 cases in each group. Intraoperative tumor tissue samples were kept and fluorescence quantitative PCR was used to determine the mRNA expression of oncogenes and tumor suppressor genes. Enzymelinked immunosorbent assay was used to determine serum contents of angiogenesis factors in observation group before operation. Results: Hepatic ultrasonic SWV level in observation group was significantly higher than that in normal control group; proto-oncogene CK, Ki67, Gly-3, Survivin and Pokemon mRNA expression in tumor tissue of high SWV group were higher than those of low SWV group while tumor suppressor genes Tg737, p16, p27, PTEN and runx3 mRNA expression were lower than those of low SWV group; serum angiogenesis factors VEGF, MMP-9 and IGF-1R contents were higher than those in low SWV group. Conclusion: The hepatic ultrasonic SWV level increases in patients with primary liver cancer, and the SWV level is directly correlated with oncogene and tumor suppressor gene expression as well as angiogenesis factor contents.

  14. Genome-Wide DNA Methylation Indicates Silencing of Tumor Suppressor Genes in Uterine Leiomyoma

    Science.gov (United States)

    Navarro, Antonia; Yin, Ping; Monsivais, Diana; Lin, Simon M.; Du, Pan; Wei, Jian-Jun; Bulun, Serdar E.

    2012-01-01

    Background Uterine leiomyomas, or fibroids, represent the most common benign tumor of the female reproductive tract. Fibroids become symptomatic in 30% of all women and up to 70% of African American women of reproductive age. Epigenetic dysregulation of individual genes has been demonstrated in leiomyoma cells; however, the in vivo genome-wide distribution of such epigenetic abnormalities remains unknown. Principal Findings We characterized and compared genome-wide DNA methylation and mRNA expression profiles in uterine leiomyoma and matched adjacent normal myometrial tissues from 18 African American women. We found 55 genes with differential promoter methylation and concominant differences in mRNA expression in uterine leiomyoma versus normal myometrium. Eighty percent of the identified genes showed an inverse relationship between DNA methylation status and mRNA expression in uterine leiomyoma tissues, and the majority of genes (62%) displayed hypermethylation associated with gene silencing. We selected three genes, the known tumor suppressors KLF11, DLEC1, and KRT19 and verified promoter hypermethylation, mRNA repression and protein expression using bisulfite sequencing, real-time PCR and western blot. Incubation of primary leiomyoma smooth muscle cells with a DNA methyltransferase inhibitor restored KLF11, DLEC1 and KRT19 mRNA levels. Conclusions These results suggest a possible functional role of promoter DNA methylation-mediated gene silencing in the pathogenesis of uterine leiomyoma in African American women. PMID:22428009

  15. Mutation analysis of suppressor of cytokine signalling 3, a candidate gene in Type 1 diabetes and insulin sensitivity

    DEFF Research Database (Denmark)

    Gylvin, T; Nolsøe, R; Hansen, T

    2004-01-01

    Beta cell loss in Type 1 and Type 2 diabetes mellitus may result from apoptosis and necrosis induced by inflammatory mediators. The suppressor of cytokine signalling (SOCS)-3 is a natural inhibitor of cytokine signalling and also influences insulin signalling. SOCS3 could therefore be a candidate...... gene in the development of Type 1 and Type 2 diabetes mellitus....

  16. Altered gene expression in blood and sputum in COPD frequent exacerbators in the ECLIPSE cohort.

    Directory of Open Access Journals (Sweden)

    Dave Singh

    Full Text Available Patients with chronic obstructive pulmonary disease (COPD who are defined as frequent exacerbators suffer with 2 or more exacerbations every year. The molecular mechanisms responsible for this phenotype are poorly understood. We investigated gene expression profile patterns associated with frequent exacerbations in sputum and blood cells in a well-characterised cohort. Samples from subjects from the ECLIPSE COPD cohort were used; sputum and blood samples from 138 subjects were used for microarray gene expression analysis, while blood samples from 438 subjects were used for polymerase chain reaction (PCR testing. Using microarray, 150 genes were differentially expressed in blood (>±1.5 fold change, p≤0.01 between frequent compared to non-exacerbators. In sputum cells, only 6 genes were differentially expressed. The differentially regulated genes in blood included downregulation of those involved in lymphocyte signalling and upregulation of pro-apoptotic signalling genes. Multivariate analysis of the microarray data followed by confirmatory PCR analysis identified 3 genes that predicted frequent exacerbations; B3GNT, LAF4 and ARHGEF10. The sensitivity and specificity of these 3 genes to predict the frequent exacerbator phenotype was 88% and 33% respectively. There are alterations in systemic immune function associated with frequent exacerbations; down-regulation of lymphocyte function and a shift towards pro-apoptosis mechanisms are apparent in patients with frequent exacerbations.

  17. Suppressors of DnaAATP imposed overinitiation in Escherichia coli

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Riber, Leise; Cohen, Malene

    2011-01-01

    Chromosome replication in Escherichia coli is limited by the supply of DnaA associated with ATP. Cells deficient in RIDA (Regulatory Inactivation of DnaA) due to a deletion of the hda gene accumulate suppressor mutations (hsm) to counteract the overinitiation caused by an elevated DnaAATP level....... Eight spontaneous hda suppressor mutations were identified by whole-genome sequencing, and three of these were analysed further. Two mutations (hsm-2 and hsm-4) mapped in the dnaA gene and led to a reduced ability to initiate replication from oriC. One mutation (hsm-1) mapped to the seqA promoter...

  18. Clinical Utility of promoter methylation of the tumor suppressor genes DKK3, and RASSF1A in breast cancer patients

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    Marwa H. Saied

    2018-04-01

    Full Text Available Background: DNA methylation is the commonest known epigenetic change that results in silencing of tumor suppressor genes. Promoter methylation of tumor suppressor genes has the potential for early detection of breast cancer. Aim: Aim is to examine the potential usefulness of blood based methylation specific polymerase chain reaction (MSP of methylated DKK3 and RASSF1A genes in early detection of breast cancer. Method: Methylation status of DKK3 and RASSF1 was investigated in forty breast cancer patients, twenty fibroadenoma patients and twenty healthy ladies as control group using MSP. Results: Methylation of DKK3 promoter was found in 22.5% of breast cancer patients, while DKK3 methylation was absent in both fibroadenoma patients and control group. Similarly, methylation of RASSF1 promoter was found in 17.5% of breast cancer patients and in none of fibroadenoma and control group. Conclusion: Promoter methylation of DKK3 and RASSF1 was found in breast cancer patients while absent in control group suggesting that tumorspecific methylation of the two genes (DKK3 and RASSF1A might be a valuable biomarker for the early detection of breast cancer. Keywords: DNA methylation, Breast cancer, DKK3, RASSF1

  19. Functional characterization of duplicated Suppressor of Overexpression of Constans 1-like genes in petunia.

    Science.gov (United States)

    Preston, Jill C; Jorgensen, Stacy A; Jha, Suryatapa G

    2014-01-01

    Flowering time is strictly controlled by a combination of internal and external signals that match seed set with favorable environmental conditions. In the model plant species Arabidopsis thaliana (Brassicaceae), many of the genes underlying development and evolution of flowering have been discovered. However, much remains unknown about how conserved the flowering gene networks are in plants with different growth habits, gene duplication histories, and distributions. Here we functionally characterize three homologs of the flowering gene Suppressor Of Overexpression of Constans 1 (SOC1) in the short-lived perennial Petunia hybrida (petunia, Solanaceae). Similar to A. thaliana soc1 mutants, co-silencing of duplicated petunia SOC1-like genes results in late flowering. This phenotype is most severe when all three SOC1-like genes are silenced. Furthermore, expression levels of the SOC1-like genes Unshaven (UNS) and Floral Binding Protein 21 (FBP21), but not FBP28, are positively correlated with developmental age. In contrast to A. thaliana, petunia SOC1-like gene expression did not increase with longer photoperiods, and FBP28 transcripts were actually more abundant under short days. Despite evidence of functional redundancy, differential spatio-temporal expression data suggest that SOC1-like genes might fine-tune petunia flowering in response to photoperiod and developmental stage. This likely resulted from modification of SOC1-like gene regulatory elements following recent duplication, and is a possible mechanism to ensure flowering under both inductive and non-inductive photoperiods.

  20. Functional characterization of duplicated Suppressor of Overexpression of Constans 1-like genes in petunia.

    Directory of Open Access Journals (Sweden)

    Jill C Preston

    Full Text Available Flowering time is strictly controlled by a combination of internal and external signals that match seed set with favorable environmental conditions. In the model plant species Arabidopsis thaliana (Brassicaceae, many of the genes underlying development and evolution of flowering have been discovered. However, much remains unknown about how conserved the flowering gene networks are in plants with different growth habits, gene duplication histories, and distributions. Here we functionally characterize three homologs of the flowering gene Suppressor Of Overexpression of Constans 1 (SOC1 in the short-lived perennial Petunia hybrida (petunia, Solanaceae. Similar to A. thaliana soc1 mutants, co-silencing of duplicated petunia SOC1-like genes results in late flowering. This phenotype is most severe when all three SOC1-like genes are silenced. Furthermore, expression levels of the SOC1-like genes Unshaven (UNS and Floral Binding Protein 21 (FBP21, but not FBP28, are positively correlated with developmental age. In contrast to A. thaliana, petunia SOC1-like gene expression did not increase with longer photoperiods, and FBP28 transcripts were actually more abundant under short days. Despite evidence of functional redundancy, differential spatio-temporal expression data suggest that SOC1-like genes might fine-tune petunia flowering in response to photoperiod and developmental stage. This likely resulted from modification of SOC1-like gene regulatory elements following recent duplication, and is a possible mechanism to ensure flowering under both inductive and non-inductive photoperiods.

  1. Genomic Analyses Reveal Global Functional Alterations That Promote Tumor Growth and Novel Tumor Suppressor Genes in Natural Killer-Cell Malignancies

    DEFF Research Database (Denmark)

    Kucuk, Can; Iqbal, Javeed; J. deLeeuw, Ronald

    in cell proliferation, growth and energy metabolic processes important for the neoplastic cells. In deleted regions, genes showing decreased expression included transcription factors or repressors (e.g. SP4, PRDM1, NCOR1 and ZNF10), tumor suppressors or negative regulators of the cell cycle (e.g. CDKN2C...

  2. Molecular Analysis: Microsatellite Instability and Loss of Heterozygosity of Tumor Suppressor Gene in Hereditary Non-Polyposis Colorectal Cancer (HNPCC

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    Vesna Hadžiavdić

    2009-02-01

    Full Text Available HNPCC (Hereditary non-polyposis colorectal cancer development is caused by mutation of genes included in system of mismatch repair genes. The mutation exists at 60% of patients in hMSH2 gene, 30% in hMLH1 and 10% both in hPMS1and hPMS2 genes. RER+ exists in about 90% in hereditary non-polyposis colorectal cancer and about 15-28% in sporadic cancers.The purpose of the study was to determine highly sensitive microsatellite markers which can be fast and efficient way of microsatellite screening for detection of HNPCC patients. Moreover, we have analysed the loss of heterozygosity of tumour suppressor genes which could have the diagnostic value in detection of HPNCC patients.

  3. Isoform-specific interactions of the von Hippel-Lindau tumor suppressor protein

    OpenAIRE

    Minervini, Giovanni; Mazzotta, Gabriella M.; Masiero, Alessandro; Sartori, Elena; Corr?, Samantha; Potenza, Emilio; Costa, Rodolfo; Tosatto, Silvio C. E.

    2015-01-01

    Deregulation of the von Hippel-Lindau tumor suppressor protein (pVHL) is considered one of the main causes for malignant renal clear-cell carcinoma (ccRCC) insurgence. In human, pVHL exists in two isoforms, pVHL19 and pVHL30 respectively, displaying comparable tumor suppressor abilities. Mutations of the p53 tumor suppressor gene have been also correlated with ccRCC insurgence and ineffectiveness of treatment. A recent proteomic analysis linked full length pVHL30 with p53 pathway regulation t...

  4. Reduced rates of gene loss, gene silencing, and gene mutation in Dnmt1-deficient embryonic stem cells

    NARCIS (Netherlands)

    Chan, M.F.; van Amerongen, R.; Nijjar, T.; Cuppen, E.; Jones, P.A.; Laird, P.W.

    2001-01-01

    Tumor suppressor gene inactivation is a crucial event in oncogenesis. Gene inactivation mechanisms include events resulting in loss of heterozygosity (LOH), gene mutation, and transcriptional silencing. The contribution of each of these different pathways varies among tumor suppressor genes and by

  5. The effect of adenovirus-mediated gene expression of FHIT in small cell lung cancer cells

    DEFF Research Database (Denmark)

    Zandi, Roza; Xu, Kai; Poulsen, Hans S

    2011-01-01

    The candidate tumor suppressor fragile histidine traid (FHIT) is frequently inactivated in small cell lung cancer (SCLC). Mutations in the p53 gene also occur in the majority of SCLC leading to the accumulation of the mutant protein. Here we evaluated the effect of FHIT gene therapy alone...

  6. Characterization of a human MSX-2 cDNA and its fragment isolated as a transformation suppressor gene against v-Ki-ras oncogene.

    Science.gov (United States)

    Takahashi, C; Akiyama, N; Matsuzaki, T; Takai, S; Kitayama, H; Noda, M

    1996-05-16

    A cDNA (termed CT124) encoding a carboxyl-terminal fragment of the human homeobox protein MSX-2 was found to induce flat reversion when expressed in v-Ki-ras-transformed NIH3T3 cells. Although the expression of endogenous MSX-2 gene is low in most of the normal adult tissues examined, it is frequently activated in carcinoma-derived cell lines. Likewise, the gene is inactive in NIH3T3 cells but is transcriptionally activated after transformation by v-Ki-ras oncogene, suggesting that the intact MSX-2 may play a positive, rather than suppressive, role in cell transformation. To test this possibility, we isolated a near full-length human MSX-2 cDNA and tested its activities in two cell systems, i.e. fibroblast and myoblast. In NIH3T3 fibroblasts, although the gene by itself failed to confer a transformed phenotype, antisense MSX-2 cDNA as well as truncated CT124 cDNA interfered with the transforming activities of v-Ki-ras oncogene. In C2C12 myoblasts, MSX-2 was found to suppress MyoD gene expression, as do activated ras oncogenes, under certain culture conditions, and CT124 was found to inhibit the activities of both MSX-2 and ras in this system as well. Our findings not only suggest that CT124 may act as a dominant suppressor of MSX-2 but also raise the possibility that MSX-2 gene may be an important downstream target for the Ras signaling pathways.

  7. Genetic and Epigenetic Tumor Suppressor Gene Silencing Are Distinct Molecular Phenotypes Driven by Growth Promoting Mutations in Nonsmall Cell Lung Cancer

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    Carmen J. Marsit

    2008-01-01

    Full Text Available Both genetic and epigenetic alterations characterize human nonsmall cell lung cancer (NSCLC, but the biological processes that create or select these alterations remain incompletely investigated. Our hypothesis posits that a roughly reciprocal relationship between the propensity for promoter hypermethylation and a propensity for genetic deletion leads to distinct molecular phenotypes of lung cancer. To test this hypothesis, we examined promoter hypermethylation of 17 tumor suppressor genes, as a marker of epigenetic alteration propensity, and deletion events at the 3p21 region, as a marker of genetic alteration. To model the complex biology between these somatic alterations, we utilized an item response theory model. We demonstrated that tumors exhibiting LOH at greater than 30% of informative alleles in the 3p21 region have a significantly reduced propensity for hypermethylation. At the same time, tumors with activating KRAS mutations showed a significantly increased propensity for hypermethylation of the loci examined, a result similar to what has been observed in colon cancer. These data suggest that NSCLCs have distinct epigenetic or genetic alteration phenotypes acting upon tumor suppressor genes and that mutation of oncogenic growth promoting genes, such as KRAS, is associated with the epigenetic phenotype.

  8. The Quest for the 1p36 Tumor Suppressor

    Science.gov (United States)

    Bagchi, Anindya; Mills, Alea A.

    2010-01-01

    Genomic analyses of late-stage human cancers have uncovered deletions encompassing 1p36, thereby providing an extensive body of literature supporting the idea that a potent tumor suppressor resides in this interval. Although a number of genes have been proposed as 1p36 candidate tumor suppressors, convincing evidence that their encoded products protect from cancer has been scanty. A recent functional study identified CHD5 as a novel tumor suppressor mapping to 1p36. Here we discuss evidence supporting CHD5’s tumor suppressive role. Together, these findings suggest that strategies designed to enhance CHD5 activity could provide novel approaches for treating a broad range of human malignancies. PMID:18413720

  9. Frequent expression loss of Inter-alpha-trypsin inhibitor heavy chain (ITIH genes in multiple human solid tumors: A systematic expression analysis

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    Werbowetski-Ogilvie Tamra

    2008-01-01

    Full Text Available Abstract Background The inter-alpha-trypsin inhibitors (ITI are a family of plasma protease inhibitors, assembled from a light chain – bikunin, encoded by AMBP – and five homologous heavy chains (encoded by ITIH1, ITIH2, ITIH3, ITIH4, and ITIH5, contributing to extracellular matrix stability by covalent linkage to hyaluronan. So far, ITIH molecules have been shown to play a particularly important role in inflammation and carcinogenesis. Methods We systematically investigated differential gene expression of the ITIH gene family, as well as AMBP and the interacting partner TNFAIP6 in 13 different human tumor entities (of breast, endometrium, ovary, cervix, stomach, small intestine, colon, rectum, lung, thyroid, prostate, kidney, and pancreas using cDNA dot blot analysis (Cancer Profiling Array, CPA, semiquantitative RT-PCR and immunohistochemistry. Results We found that ITIH genes are clearly downregulated in multiple human solid tumors, including breast, colon and lung cancer. Thus, ITIH genes may represent a family of putative tumor suppressor genes that should be analyzed in greater detail in the future. For an initial detailed analysis we chose ITIH2 expression in human breast cancer. Loss of ITIH2 expression in 70% of cases (n = 50, CPA could be confirmed by real-time PCR in an additional set of breast cancers (n = 36. Next we studied ITIH2 expression on the protein level by analyzing a comprehensive tissue micro array including 185 invasive breast cancer specimens. We found a strong correlation (p Conclusion Altogether, this is the first systematic analysis on the differential expression of ITIH genes in human cancer, showing frequent downregulation that may be associated with initiation and/or progression of these malignancies.

  10. Frequent silencing of RASSF1A by DNA methylation in thymic neuroendocrine tumours.

    Science.gov (United States)

    Kajiura, Koichiro; Takizawa, Hiromitsu; Morimoto, Yuki; Masuda, Kiyoshi; Tsuboi, Mitsuhiro; Kishibuchi, Reina; Wusiman, Nuliamina; Sawada, Toru; Kawakita, Naoya; Toba, Hiroaki; Yoshida, Mitsuteru; Kawakami, Yukikiyo; Naruto, Takuya; Imoto, Issei; Tangoku, Akira; Kondo, Kazuya

    2017-09-01

    Aberrant methylation of promoter CpG islands (CGIs) of tumour suppressor genes is a common epigenetic mechanism underlying cancer pathogenesis. The methylation patterns of thymic tumours have not been studied in detail since such tumours are rare. Herein, we sought to identify genes that could serve as epigenetic targets for thymic neuroendocrine tumour (NET) therapy. Genome-wide screening for aberrantly methylated CGIs was performed in three NET samples, seven thymic carcinoma (TC) samples, and eight type-B3 thymoma samples. The methylation status of thymic epithelial tumours (TETs) samples was validated by pyrosequencing in a larger cohort. The expression status was analysed by quantitative polymerase chain reaction (PCR) and immunohistochemistry. We identified a CGI on a novel gene, RASSF1A, which was strongly hypermethylated in NET, but not in thymic carcinoma or B3 thymoma. RASSF1A was identified as a candidate gene statistically and bibliographically, as it showed frequent CGI hypermethylation in NET by genome-wide screening. Pyrosequencing confirmed significant hypermethylation of a RASSF1A CGI in NET. Low-grade NET tissue was more strongly methylated than high-grade NET. Quantitative PCR and immunohistochemical staining revealed that RASSF1A mRNA and protein expression levels were negatively regulated by DNA methylation. RASSF1A is a tumour suppressor gene epigenetically dysregulated in NET. Aberrant methylation of RASSF1A has been reported in various tumours, but this is the first report of RASSF1A hypermethylation in TETs. RASSF1A may represent an epigenetic therapeutic target in thymic NET. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Identification of a region of frequent loss of heterozygosity at 11q24 in colorectal cancer.

    Science.gov (United States)

    Connolly, K C; Gabra, H; Millwater, C J; Taylor, K J; Rabiasz, G J; Watson, J E; Smyth, J F; Wyllie, A H; Jodrell, D I

    1999-06-15

    Loss of heterozygosity (LOH) at 11q23-qter occurs frequently in ovarian and other cancers, but for colorectal cancer, the evidence is conflicting. Seven polymorphic loci were analyzed between D11S897 and D11S969 in 50 colorectal tumors. Two distinct LOH regions were detected, suggesting possible sites for tumor-suppressor genes involved in colorectal neoplasia: a large centromeric region between D11S897 and D11S925, and a telomeric 4.9-Mb region between D11S912 and D11S969. There was no correlation with clinicopathological features. This analysis describes a region of LOH in the region 11q23.3-24.3 for the first time in colorectal cancer and provides complementary evidence for the ongoing effort to identify the gene(s) involved.

  12. Retinoid-induced expression and activity of an immediate early tumor suppressor gene in vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Jeffrey W Streb

    2011-04-01

    Full Text Available Retinoids are used clinically to treat a number of hyper-proliferative disorders and have been shown in experimental animals to attenuate vascular occlusive diseases, presumably through nuclear receptors bound to retinoic acid response elements (RARE located in target genes. Here, we show that natural or synthetic retinoids rapidly induce mRNA and protein expression of a specific isoform of A-Kinase Anchoring Protein 12 (AKAP12β in cultured smooth muscle cells (SMC as well as the intact vessel wall. Expression kinetics and actinomycin D studies indicate Akap12β is a retinoid-induced, immediate-early gene. Akap12β promoter analyses reveal a conserved RARE mildly induced with atRA in a region that exhibits hyper-acetylation. Immunofluorescence microscopy and protein kinase A (PKA regulatory subunit overlay assays in SMC suggest a physical association between AKAP12β and PKA following retinoid treatment. Consistent with its designation as a tumor suppressor, inducible expression of AKAP12β attenuates SMC growth in vitro. Further, immunohistochemistry studies establish marked decreases in AKAP12 expression in experimentally-injured vessels of mice as well as atheromatous lesions in humans. Collectively, these results demonstrate a novel role for retinoids in the induction of an AKAP tumor suppressor that blocks vascular SMC growth thus providing new molecular insight into how retiniods may exert their anti-proliferative effects in the injured vessel wall.

  13. Fish Suppressors of Cytokine Signaling (SOCS): Gene Discovery, Modulation of Expression and Function

    Science.gov (United States)

    Wang, Tiehui; Gorgoglione, Bartolomeo; Maehr, Tanja; Holland, Jason W.; Vecino, Jose L. González; Wadsworth, Simon; Secombes, Christopher J.

    2011-01-01

    The intracellular suppressors of cytokine signaling (SOCS) family members, including CISH and SOCS1 to 7 in mammals, are important regulators of cytokine signaling pathways. So far, the orthologues of all the eight mammalian SOCS members have been identified in fish, with several of them having multiple copies. Whilst fish CISH, SOCS3, and SOCS5 paralogues are possibly the result of the fish-specific whole genome duplication event, gene duplication or lineage-specific genome duplication may also contribute to some paralogues, as with the three trout SOCS2s and three zebrafish SOCS5s. Fish SOCS genes are broadly expressed and also show species-specific expression patterns. They can be upregulated by cytokines, such as IFN-γ, TNF-α, IL-1β, IL-6, and IL-21, by immune stimulants such as LPS, poly I:C, and PMA, as well as by viral, bacterial, and parasitic infections in member- and species-dependent manners. Initial functional studies demonstrate conserved mechanisms of fish SOCS action via JAK/STAT pathways. PMID:22203897

  14. Positive selection of deleterious alleles through interaction with a sex-ratio suppressor gene in African Buffalo: a plausible new mechanism for a high frequency anomaly.

    Directory of Open Access Journals (Sweden)

    Pim van Hooft

    Full Text Available Although generally rare, deleterious alleles can become common through genetic drift, hitchhiking or reductions in selective constraints. Here we present a possible new mechanism that explains the attainment of high frequencies of deleterious alleles in the African buffalo (Syncerus caffer population of Kruger National Park, through positive selection of these alleles that is ultimately driven by a sex-ratio suppressor. We have previously shown that one in four Kruger buffalo has a Y-chromosome profile that, despite being associated with low body condition, appears to impart a relative reproductive advantage, and which is stably maintained through a sex-ratio suppressor. Apparently, this sex-ratio suppressor prevents fertility reduction that generally accompanies sex-ratio distortion. We hypothesize that this body-condition-associated reproductive advantage increases the fitness of alleles that negatively affect male body condition, causing genome-wide positive selection of these alleles. To investigate this we genotyped 459 buffalo using 17 autosomal microsatellites. By correlating heterozygosity with body condition (heterozygosity-fitness correlations, we found that most microsatellites were associated with one of two gene types: one with elevated frequencies of deleterious alleles that have a negative effect on body condition, irrespective of sex; the other with elevated frequencies of sexually antagonistic alleles that are negative for male body condition but positive for female body condition. Positive selection and a direct association with a Y-chromosomal sex-ratio suppressor are indicated, respectively, by allele clines and by relatively high numbers of homozygous deleterious alleles among sex-ratio suppressor carriers. This study, which employs novel statistical techniques to analyse heterozygosity-fitness correlations, is the first to demonstrate the abundance of sexually-antagonistic genes in a natural mammal population. It also has

  15. Recurrent pregnancy failure is associated with a polymorphism in the p53 tumour suppressor gene.

    Science.gov (United States)

    Pietrowski, Detlef; Bettendorf, Hertha; Riener, Eva-Katrin; Keck, Christoph; Hefler, Lukas A; Huber, Johannes C; Tempfer, Clemens

    2005-04-01

    The p53 tumour suppressor gene is a well-known factor regulating apoptosis in a wide variety of cells and tissues. Alterations in the p53 gene are among the most common genetic changes in human cancers. In addition, recent data provide evidence that p53 plays a critical role in mediating pregnancy by regulating steroid hormone activation. In idiopathic recurrent miscarriages (IRM), causes and associations are much debated as the exact pathophysiological mechanisms are unknown. In this study, we assess whether an established polymorphism in the p53 gene is associated with the occurrence of IRM. Genotyping was performed by PCR-based amplification of the p53 Arg and Pro variants at codon 72 in 175 cases of IRM and 143 controls. We observed a statistically significant association between carriage of the Pro allele and the occurrence of IRM (P = 0.03, odds ratio 1.49, confidence interval 1.04-2.14). Distribution of genotypes was in Hardy-Weinberg equilibrium. Our results indicate an over-representation of the Pro allele of the p53 gene in women with IRM, giving support to the theory that p53 has a potential role during pregnancy.

  16. Differential splicing of oncogenes and tumor suppressor genes in African and Caucasian American populations: contributing factor in prostate cancer disparities

    Science.gov (United States)

    2017-12-01

    populations: contributing factor in prostate cancer disparities? PRINCIPAL INVESTIGATOR: Norman H Lee, PhD CONTRACTING ORGANIZATION: George Washington...splicing of oncogenes and tumor suppressor genes in African and Caucasian American populations: contributing factor in prostate cancer disparities? 5b...American (AA) versus Caucasian American (CA) prostate cancer (PCa). We focused our efforts on two oncogenes, phosphatidylinositol-4,5-bisphosphate 3

  17. Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

    Science.gov (United States)

    Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

    1992-07-15

    Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance.

  18. Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

    Science.gov (United States)

    Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

    1992-01-01

    Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance. Images PMID:1631137

  19. Phytochemical Compositions of Immature Wheat Bran, and Its Antioxidant Capacity, Cell Growth Inhibition, and Apoptosis Induction through Tumor Suppressor Gene

    Directory of Open Access Journals (Sweden)

    Mi Jeong Kim

    2016-09-01

    Full Text Available The purpose of this study was to investigate the phytochemical compositions and antioxidant capacity, cell growth inhibition, and apoptosis induction in extracts of immature wheat bran. Immature wheat bran (IWB was obtained from immature wheat harvested 10 days earlier than mature wheat. The phytochemical compositions of bran extract samples were analyzed by ultra-high performance liquid chromatography. The total ferulic acid (3.09 mg/g and p-coumaric acid (75 µg/g in IWB were significantly higher than in mature wheat bran (MWB, ferulic acid: 1.79 mg/g; p-coumaric acid: 55 µg/g. The oxygen radical absorbance capacity (ORAC: 327 µM Trolox equivalents (TE/g and cellular antioxidant activity (CAA: 4.59 µM Quercetin equivalents (QE/g of the IWB were higher than those of the MWB (ORAC: 281 µM TE/g; CAA: 0.63 µM QE/g. When assessing cell proliferation, the IWB extracts resulted in the lowest EC50 values against HT-29 (18.9 mg/mL, Caco-2 (7.74 mg/mL, and HeLa cells (8.17 mg/mL among bran extract samples. Additionally, the IWB extracts increased the gene expression of p53 and PTEN (tumor suppressor genes in HT-29 cells, indicating inhibited cell growth and induced apoptosis through tumor suppressor genes.

  20. Frequent expression loss of Inter-alpha-trypsin inhibitor heavy chain (ITIH) genes in multiple human solid tumors: A systematic expression analysis

    International Nuclear Information System (INIS)

    Hamm, Alexander; Knuechel, Ruth; Dahl, Edgar; Veeck, Juergen; Bektas, Nuran; Wild, Peter J; Hartmann, Arndt; Heindrichs, Uwe; Kristiansen, Glen; Werbowetski-Ogilvie, Tamra; Del Maestro, Rolando

    2008-01-01

    The inter-alpha-trypsin inhibitors (ITI) are a family of plasma protease inhibitors, assembled from a light chain – bikunin, encoded by AMBP – and five homologous heavy chains (encoded by ITIH1, ITIH2, ITIH3, ITIH4, and ITIH5), contributing to extracellular matrix stability by covalent linkage to hyaluronan. So far, ITIH molecules have been shown to play a particularly important role in inflammation and carcinogenesis. We systematically investigated differential gene expression of the ITIH gene family, as well as AMBP and the interacting partner TNFAIP6 in 13 different human tumor entities (of breast, endometrium, ovary, cervix, stomach, small intestine, colon, rectum, lung, thyroid, prostate, kidney, and pancreas) using cDNA dot blot analysis (Cancer Profiling Array, CPA), semiquantitative RT-PCR and immunohistochemistry. We found that ITIH genes are clearly downregulated in multiple human solid tumors, including breast, colon and lung cancer. Thus, ITIH genes may represent a family of putative tumor suppressor genes that should be analyzed in greater detail in the future. For an initial detailed analysis we chose ITIH2 expression in human breast cancer. Loss of ITIH2 expression in 70% of cases (n = 50, CPA) could be confirmed by real-time PCR in an additional set of breast cancers (n = 36). Next we studied ITIH2 expression on the protein level by analyzing a comprehensive tissue micro array including 185 invasive breast cancer specimens. We found a strong correlation (p < 0.001) between ITIH2 expression and estrogen receptor (ER) expression indicating that ER may be involved in the regulation of this ECM molecule. Altogether, this is the first systematic analysis on the differential expression of ITIH genes in human cancer, showing frequent downregulation that may be associated with initiation and/or progression of these malignancies

  1. Frequent silencing of the candidate tumor suppressor TRIM58 by promoter methylation in early-stage lung adenocarcinoma.

    Science.gov (United States)

    Kajiura, Koichiro; Masuda, Kiyoshi; Naruto, Takuya; Kohmoto, Tomohiro; Watabnabe, Miki; Tsuboi, Mitsuhiro; Takizawa, Hiromitsu; Kondo, Kazuya; Tangoku, Akira; Imoto, Issei

    2017-01-10

    In this study, we aimed to identify novel drivers that would be epigenetically altered through aberrant methylation in early-stage lung adenocarcinoma (LADC), regardless of the presence or absence of tobacco smoking-induced epigenetic field defects. Through genome-wide screening for aberrantly methylated CpG islands (CGIs) in 12 clinically uniform, stage-I LADC cases affecting six non-smokers and six smokers, we identified candidate tumor-suppressor genes (TSGs) inactivated by hypermethylation. Through systematic expression analyses of those candidates in panels of additional tumor samples and cell lines treated or not treated with 5-aza-deoxycitidine followed by validation analyses of cancer-specific silencing by CGI hypermethylation using a public database, we identified TRIM58 as the most prominent candidate for TSG. TRIM58 was robustly silenced by hypermethylation even in early-stage primary LADC, and the restoration of TRIM58 expression in LADC cell lines inhibited cell growth in vitro and in vivo in anchorage-dependent and -independent manners. Our findings suggest that aberrant inactivation of TRIM58 consequent to CGI hypermethylation might stimulate the early carcinogenesis of LADC regardless of smoking status; furthermore, TRIM58 methylation might be a possible early diagnostic and epigenetic therapeutic target in LADC.

  2. A single mutation in the 15S rRNA gene confers nonsense suppressor activity and interacts with mRF1 the release factor in yeast mitochondria

    Directory of Open Access Journals (Sweden)

    Ali Gargouri

    2015-08-01

    Full Text Available We have determined the nucleotide sequence of the mim3-1 mitochondrial ribosomal suppressor, acting on ochre mitochondrial mutations and one frameshift mutation in Saccharomyces cerevisiae. The 15s rRNA suppressor gene contains a G633 to C transversion. Yeast mitochondrial G633 corresponds to G517 of the E.coli 15S rRNA, which is occupied by an invariant G in all known small rRNA sequences. Interestingly, this mutation has occurred at the same position as the known MSU1 mitochondrial suppressor which changes G633 to A. The suppressor mutation lies in a highly conserved region of the rRNA, known in E.coli as the 530-loop, interacting with the S4, S5 and S12 ribosomal proteins. We also show an interesting interaction between the mitochondrial mim3-1 and the nuclear nam3-1 suppressors, both of which have the same action spectrum on mitochondrial mutations: nam3-1 abolishes the suppressor effect when present with mim3-1 in the same haploid cell. We discuss these results in the light of the nature of Nam3, identified by [1] as the yeast mitochondrial translation release factor. A hypothetical mechanism of suppression by "ribosome shifting" is also discussed in view of the nature of mutations suppressed and not suppressed.

  3. Frequent gain and loss of introns in fungal cytochrome b genes.

    Directory of Open Access Journals (Sweden)

    Liang-Fen Yin

    Full Text Available In this study, all available cytochrome b (Cyt b genes from the GOBASE database were compiled and the evolutionary dynamics of the Cyt b gene introns was assessed. Cyt b gene introns were frequently present in the fungal kingdom and some lower plants, but generally absent or rare in Chromista, Protozoa, and Animalia. Fungal Cyt b introns were found at 35 positions in Cyt b genes and the number of introns varied at individual positions from a single representative to 32 different introns at position 131, showing a wide and patchy distribution. Many homologous introns were present at the same position in distantly related species but absent in closely related species, suggesting that introns of the Cyt b genes were frequently lost. On the other hand, highly similar intron sequences were observed in some distantly related species rather than in closely related species, suggesting that these introns were gained independently, likely through lateral transfers. The intron loss-and-gain events could be mediated by transpositions that might have occurred between nuclear and mitochondria. Southern hybridization analysis confirmed that some introns contained repetitive sequences and might be transposable elements. An intron gain in Botryotinia fuckeliana prevented the development of QoI fungicide resistance, suggesting that intron loss-and-gain events were not necessarily beneficial to their host organisms.

  4. Genetic and Epigenetic Tumor Suppressor Gene Silencing are Distinct Molecular Phenotypes Driven by Growth Promoting Mutations in Non small Cell Lung Cancer

    International Nuclear Information System (INIS)

    Marsit, C. J.; Kelsey, K. T.; Houseman, E. A.; Kelsey, K. T.; Houseman, E. A.; Nelson, H. H.

    2008-01-01

    Both genetic and epigenetic alterations characterize human non small cell lung cancer (NSCLC), but the biological processes that create or select these alterations remain incompletely investigated. Our hypothesis posits that a roughly reciprocal relationship between the propensity for promoter hyper methylation and a propensity for genetic deletion leads to distinct molecular phenotypes of lung cancer. To test this hypothesis, we examined promoter hyper methylation of 17 tumor suppressor genes, as a marker of epigenetic alteration propensity, and deletion events at the 3p21 region, as a marker of genetic alteration. To model the complex biology between these somatic alterations, we utilized an item response theory model. We demonstrated that tumors exhibiting LOH at greater than 30% of informative alleles in the 3p21 region have a significantly reduced propensity for hyper methylation. At the same time, tumors with activating KRAS mutations showed a significantly increased propensity for hyper methylation of the loci examined, a result similar to what has been observed in colon cancer. These data suggest that NSCLCs have distinct epigenetic or genetic alteration phenotypes acting upon tumor suppressor genes and that mutation of oncogenic growth promoting genes, such as KRAS, is associated with the epigenetic phenotype.

  5. P53 and Rb tumor suppressor gene alterations in gastric cancer Alterações dos genes supressores tumorais p53 e Rb no câncer gástrico

    Directory of Open Access Journals (Sweden)

    Rejane Mattar

    2004-01-01

    Full Text Available Inactivation of tumor suppressor genes has been frequently observed in gastric carcinogenesis. Our purpose was to study the involvement of p53, APC, DCC, and Rb genes in gastric carcinoma. METHOD: Loss of heterozygosity of the p53, APC, DCC and Rb genes was studied in 22 gastric cancer tissues using polymerase chain reaction; single-strand conformation polymorphism of the p53 gene exons 5-6 and exons 7-8 was studied using 35S-dATP, and p53 expression was detected using a histological immunoperoxidase method with an anti-p53 clone. RESULTS AND DISCUSSION: No loss of heterozygosity was observed in any of these tumor suppressor genes; homozygous deletion was detected in the Rb gene in 23% (3/13 of the cases of intestinal-type gastric carcinoma. Eighteen (81.8% cases showed band mobility shifts in exons 5-6 and/or 7-8 of the p53 gene. The presence of the p53 protein was positive in gastric cancer cells in 14 cases (63.6%. Normal gastric mucosa showed negative staining for p53; thus, the immunoreactivity was likely to represent mutant forms. The correlation of band mobility shift and the immunoreactivity to anti-p53 was not significant (P = .90. There was no correlation of gene alterations with the disease severity. CONCLUSIONS: The inactivation of Rb and p53 genes is involved in gastric carcinogenesis in our environment. Loss of the Rb gene observed only in the intestinal-type gastric cancer should be further evaluated in association with Helicobacter pylori infection. The p53 gene was affected in both intestinal and diffuse histological types of gastric cancer.A inativação de genes supressores tumorais tem sido freqüentemente observada na carcinogênese gástrica. O nosso objetivo foi estudar o envolvimento dos genes p53, APC, DCC e Rb no câncer gástrico. MÉTODO: Vinte e dois casos de câncer gástrico foram estudados por PCR-LOH (reação de polimerase em cadeia- perda de alelo heterozigoto dos genes p53, APC, DCC e Rb; e por PCR-SSCP (rea

  6. A Restricted Spectrum of Mutations in the SMAD4 Tumor-Suppressor Gene Underlies Myhre Syndrome

    Science.gov (United States)

    Caputo, Viviana; Cianetti, Luciano; Niceta, Marcello; Carta, Claudio; Ciolfi, Andrea; Bocchinfuso, Gianfranco; Carrani, Eugenio; Dentici, Maria Lisa; Biamino, Elisa; Belligni, Elga; Garavelli, Livia; Boccone, Loredana; Melis, Daniela; Andria, Generoso; Gelb, Bruce D.; Stella, Lorenzo; Silengo, Margherita; Dallapiccola, Bruno; Tartaglia, Marco

    2012-01-01

    Myhre syndrome is a developmental disorder characterized by reduced growth, generalized muscular hypertrophy, facial dysmorphism, deafness, cognitive deficits, joint stiffness, and skeletal anomalies. Here, by performing exome sequencing of a single affected individual and coupling the results to a hypothesis-driven filtering strategy, we establish that heterozygous mutations in SMAD4, which encodes for a transducer mediating transforming growth factor β and bone morphogenetic protein signaling branches, underlie this rare Mendelian trait. Two recurrent de novo SMAD4 mutations were identified in eight unrelated subjects. Both mutations were missense changes altering Ile500 within the evolutionary conserved MAD homology 2 domain, a well known mutational hot spot in malignancies. Structural analyses suggest that the substituted residues are likely to perturb the binding properties of the mutant protein to signaling partners. Although SMAD4 has been established as a tumor suppressor gene somatically mutated in pancreatic, gastrointestinal, and skin cancers, and germline loss-of-function lesions and deletions of this gene have been documented to cause disorders that predispose individuals to gastrointestinal cancer and vascular dysplasias, the present report identifies a previously unrecognized class of mutations in the gene with profound impact on development and growth. PMID:22243968

  7. Clinical and pathological associations with p53 tumour-suppressor gene mutations and expression of p21WAF1/Cip1 in colorectal carcinoma

    NARCIS (Netherlands)

    Slebos, R. J.; Baas, I. O.; Clement, M.; Polak, M.; Mulder, J. W.; van den Berg, F. M.; Hamilton, S. R.; Offerhaus, G. J.

    1996-01-01

    Inactivation of the p53 tumour-suppressor gene is common in a wide variety of human neoplasms. In the majority of cases, single point mutations in the protein-encoding sequence of p53 lead to positive immunohistochemistry (IHC) for the p53 protein, and are accompanied by loss of the wild-type

  8. Expression level of novel tumor suppressor gene FATS is associated with the outcome of node positive breast cancer

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; GU Lin; ZHAO Lu-jun; ZHANG Xi-feng; QIU Li; LI Zheng

    2011-01-01

    Background Recently, we reported the identification of a previously uncharacterized and evolutionarily conserved gene, fragile-site associated tumor suppressor (FATS), at a frequently deleted region in irradiation (IR)-induced tumors.However, the role of FATS in breast cancer development and its clinical significance has not been defined. The aim of this study was to determine the role of FA7S in breast cancer development and to evaluate its clinical significance in breast cancer.Methods The expression level of FATS mRNA was determined in 106 breast carcinomas and 23 paired normal breast tissues using quantitative real time reverse transcription-polymerase chain reaction (RT-PCR). The relationship between FATS expression and clinicopathological parameters were also analyzed.Results The mRNA level of FATS was down-regulated in breast cancer compared with paired normal tissues. Low expression of FATS was correlated with high nuclear grade. There was a tendency to a favorable outcome for patients with high expression of FATS (P=0.346). However, low expression of FATS was associated with poor outcome of breast cancer patients with node positive (P=0.011). Furthermore, the mRNA level of FATS showed an independent value in predicting the outcome of breast cancer patients with positive lymph nodes.Conclusion FATS is involved in the carcinogenesis and development of breast cancer and could be a potential biomarker and prognostic factor for breast cancer therapy.

  9. Frequent gene conversion events between the X and Y homologous chromosomal regions in primates

    Directory of Open Access Journals (Sweden)

    Hirai Hirohisa

    2010-07-01

    Full Text Available Abstract Background Mammalian sex-chromosomes originated from a pair of autosomes. A step-wise cessation of recombination is necessary for the proper maintenance of sex-determination and, consequently, generates a four strata structure on the X chromosome. Each stratum shows a specific per-site nucleotide sequence difference (p-distance between the X and Y chromosomes, depending on the time of recombination arrest. Stratum 4 covers the distal half of the human X chromosome short arm and the p-distance of the stratum is ~10%, on average. However, a 100-kb region, which includes KALX and VCX, in the middle of stratum 4 shows a significantly lower p-distance (1-5%, suggesting frequent sequence exchanges or gene conversions between the X and Y chromosomes in humans. To examine the evolutionary mechanism for this low p-distance region, sequences of a corresponding region including KALX/Y from seven species of non-human primates were analyzed. Results Phylogenetic analysis of this low p-distance region in humans and non-human primate species revealed that gene conversion like events have taken place at least ten times after the divergence of New World monkeys and Catarrhini (i.e., Old World monkeys and hominoids. A KALY-converted KALX allele in white-handed gibbons also suggests a possible recent gene conversion between the X and Y chromosomes. In these primate sequences, the proximal boundary of this low p-distance region is located in a LINE element shared between the X and Y chromosomes, suggesting the involvement of this element in frequent gene conversions. Together with a palindrome on the Y chromosome, a segmental palindrome structure on the X chromosome at the distal boundary near VCX, in humans and chimpanzees, may mediate frequent sequence exchanges between X and Y chromosomes. Conclusion Gene conversion events between the X and Y homologous regions have been suggested, mainly in humans. Here, we found frequent gene conversions in the

  10. Inactivation of the Tumor Suppressor Genes Causing the Hereditary Syndromes Predisposing to Head and Neck Cancer via Promoter Hypermethylation in Sporadic Head and Neck Cancers

    OpenAIRE

    Smith, Ian M.; Mithani, Suhail K.; Mydlarz, Wojciech K.; Chang, Steven S.; Califano, Joseph A.

    2010-01-01

    Fanconi anemia (FA) and dyskeratosis congenita (DC) are rare inherited syndromes that cause head and neck squamous cell cancer (HNSCC). Prior studies of inherited forms of cancer have been extremely important in elucidating tumor suppressor genes inactivated in sporadic tumors. Here, we studied whether sporadic tumors have epigenetic silencing of the genes causing the inherited forms of HNSCC. Using bisulfite sequencing, we investigated the incidence of promoter hypermethylation of the 17 Fan...

  11. Analysis of the Mitogen-activated protein kinase kinase 4 (MAP2K4) tumor suppressor gene in ovarian cancer

    International Nuclear Information System (INIS)

    Davis, Sally J; Choong, David YH; Ramakrishna, Manasa; Ryland, Georgina L; Campbell, Ian G; Gorringe, Kylie L

    2011-01-01

    MAP2K4 is a putative tumor and metastasis suppressor gene frequently found to be deleted in various cancer types. We aimed to conduct a comprehensive analysis of this gene to assess its involvement in ovarian cancer. We screened for mutations in MAP2K4 using High Resolution Melt analysis of 149 primary ovarian tumors and methylation at the promoter using Methylation-Specific Single-Stranded Conformation Polymorphism analysis of 39 tumors. We also considered the clinical impact of changes in MAP2K4 using publicly available expression and copy number array data. Finally, we used siRNA to measure the effect of reducing MAP2K4 expression in cell lines. In addition to 4 previously detected homozygous deletions, we identified a homozygous 16 bp truncating deletion and a heterozygous 4 bp deletion, each in one ovarian tumor. No promoter methylation was detected. The frequency of MAP2K4 homozygous inactivation was 5.6% overall, and 9.8% in high-grade serous cases. Hemizygous deletion of MAP2K4 was observed in 38% of samples. There were significant correlations of copy number and expression in three microarray data sets. There was a significant correlation between MAP2K4 expression and overall survival in one expression array data set, but this was not confirmed in an independent set. Treatment of JAM and HOSE6.3 cell lines with MAP2K4 siRNA showed some reduction in proliferation. MAP2K4 is targeted by genetic inactivation in ovarian cancer and restricted to high grade serous and endometrioid carcinomas in our cohort

  12. Suppressor cells in transplantation tolerance II. Maturation of suppressor cells in the bone marrow chimera

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Ki, P.F.; Beschorner, W.E.; Hess, A.D.; Santos, G.W.

    1981-01-01

    Histoincompatible bone marrow allografts were established in lethally irradiated rats. At various times after transplantation, the spleen cells were harvested, subjected to mixed lymphocyte cultures, and assayed for suppressor cells in vitro and in vivo by adoptive transfer studies. Alloantigen-nonspecific suppressor cells appeared in the chimera at 40 days after grafting, coinciding with the resolution of graft-versus-host disease (GVHD). At 250 days the nonspecific suppressor cells were replaced by suppressor cells specifically suppressing donor-versus-host alloantigen responses. At 720 days suppressor cells could no longer be identified by in vitro methods but were identified by in vivo adoptive transfer of transplantation tolerance. After injection of host-type antigen into chimeras, the suppressor cells could be again demonstrated by in vitro methods

  13. Suppressor cells in transplantation tolerance. II. maturation of suppressor cells in the bone marrow chimera

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Ki, P.F.; Beschorner, W.E.; Hess, A.D.; Santos, G.W.

    1981-01-01

    Histoincompatible bone marrow allografts were established in lethally irradiated rats. At various times after transplantation, the spleen cells were harvested, subjected to mixed lymphocyte cultures, and assayed for suppressor cells in vitro and in vivo by adoptive transfer studies. Alloantigen-nonspecific suppressor cells appeared in the chimera at 40 days after grafting, coinciding with the resolution of graft-versus-host disease (GVHD). At 250 days the nonspecific suppressor cells were replaced by suppressor cells specifically suppressing donor-versus-host alloantigen responses. At 720 days suppressor cells could no longer be identified by in vitro methods but were identified by in vivo adoptive transfer of transplantation tolerance. After injection of host-type antigen into chimeras, the suppressor cells could be again demonstrated by in vitro methods

  14. Genome-wide CpG island methylation analysis implicates novel genes in the pathogenesis of renal cell carcinoma

    OpenAIRE

    Ricketts, Christopher J.; Morris, Mark R.; Gentle, Dean; Brown, Michael; Wake, Naomi; Woodward, Emma R.; Clarke, Noel; Latif, Farida; Maher, Eamonn R.

    2012-01-01

    In order to identify novel candidate tumor suppressor genes (TSGs) implicated in renal cell carcinoma (RCC), we performed genome-wide methylation profiling of RCC using the HumanMethylation27 BeadChips to assess methylation at >14,000 genes. Two hundred and twenty hypermethylated probes representing 205 loci/genes were identified in genomic CpG islands. A subset of TSGs investigated in detail exhibited frequent tumor methylation, promoter methylation associated transcriptional silencing an...

  15. Effect of recombinant adenovirus encoding human p53 tumor suppressor gene combined with radiation therapy on human lymphoma cells lines

    International Nuclear Information System (INIS)

    Yu Zeyang; Fan Wo; Li Dongqing; Zhu Ran; Wan Jianmei; Wang Yongqing; Wu Jinchang

    2008-01-01

    This paper analyzes the inhibitory effect and radiation sensitization of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on human lymphoma cell lines. Human lymphoma cell lines were treated with rAd-p53, radiation therapy and combined treatment, respectively. The cell growth inhibition was assessed by MTF. The cell cycle and apoptosis were detected by flow cytometry, and the p53 protein expression was detected by Western blotting. The results showed that extrinsic p53 gene have expressed to some degree, but not at high level. The role of inhibition and radiation sensitivity of rAd-p53 was not significant to human lymphoma cell lines. (authors)

  16. Candidate Tumor-Suppressor Gene DLEC1 Is Frequently Downregulated by Promoter Hypermethylation and Histone Hypoacetylation in Human Epithelial Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Joseph Kwong

    2006-04-01

    Full Text Available Suppression of ovarian tumor growth by chromosome 3p was demonstrated in a previous study. Deleted in Lung and Esophageal Cancer 1 (DLEC1 on 3p22.3 is a candidate tumor suppressor in lung, esophageal, and renal cancers. The potential involvement of DLEC1 in epithelial ovarian cancer remains unknown. In the present study, DLEC1 downregulation was found in ovarian cancer cell lines and primary ovarian tumors. Focus-expressed DLEC1 in two ovarian cancer cell lines resulted in 41% to 52% inhibition of colony formation. No chromosomal loss of chromosome 3p22.3 in any ovarian cancer cell line or tissue was found. Promoter hypermethylation of DLEC1 was detected in ovarian cancer cell lines with reduced DLEC1 transcripts, whereas methylation was not detected in normal ovarian epithelium and DLEC1-expressing ovarian cancer cell lines. Treatment with demethylating agent enhanced DLEC1 expression in 90% (9 of 10 of ovarian cancer cell lines. DLEC1 promoter methylation was examined in 13 high-grade ovarian tumor tissues with DLEC1 downregulation, in which 54% of the tumors showed DLEC1 methylation. In addition, 80% of ovarian cancer cell lines significantly upregulated DLEC1 transcripts after histone deacetylase inhibitor treatment. Therefore, our results suggested that DLEC1 suppressed the growth of ovarian cancer cells and that its downregulation was closely associated with promoter hypermethylation and histone hypoacetylation.

  17. The chromatin remodelling factor BRG1 is a novel binding partner of the tumor suppressor p16INK4a

    Directory of Open Access Journals (Sweden)

    Mann Graham J

    2009-01-01

    Full Text Available Abstract Background CDKN2A/p16INK4a is frequently altered in human cancers and it is the most important melanoma susceptibility gene identified to date. p16INK4a inhibits pRb phosphorylation and induces cell cycle arrest, which is considered its main tumour suppressor function. Nevertheless, additional activities may contribute to the tumour suppressor role of p16INK4a and could help explain its specific association with melanoma predisposition. To identify such functions we conducted a yeast-two-hybrid screen for novel p16INK4a binding partners. Results We now report that p16INK4a interacts with the chromatin remodelling factor BRG1. We investigated the cooperative roles of p16INK4a and BRG1 using a panel of cell lines and a melanoma cell model with inducible p16INK4a expression and BRG1 silencing. We found evidence that BRG1 is not required for p16INK4a-induced cell cycle inhibition and propose that the p16INK4a-BRG1 complex regulates BRG1 chromatin remodelling activity. Importantly, we found frequent loss of BRG1 expression in primary and metastatic melanomas, implicating this novel p16INK4a binding partner as an important tumour suppressor in melanoma. Conclusion This data adds to the increasing evidence implicating the SWI/SNF chromatin remodelling complex in tumour development and the association of p16INK4a with chromatin remodelling highlights potentially new functions that may be important in melanoma predisposition and chemoresistance.

  18. Development of Spontaneous Mammary Tumors in BALB/c-p53+-Mice: Detection of Early Genetic Alterations and the Mapping of BALB/c Susceptibility Genes

    National Research Council Canada - National Science Library

    Blackburn, Anneke

    2002-01-01

    The TP53 tumor suppressor gene is defective in the majority of sporadic breast cancers, and breast cancer is the most frequent tumor type in women with Li-Fraumeni syndrome who inherit germline mutations in TP53...

  19. Development of Spontaneous Mammary Tumors in BALB/c-p53+/-Mice: Detection of Early Genetic Alterations and the Mapping of BALB/c Susceptibility Genes

    National Research Council Canada - National Science Library

    Smith, Sallie

    2004-01-01

    The TP53 tumor suppressor gene is defective in the majority of sporadic breast cancers, and breast cancer is the most frequent tumor type in women with Li-Fraumeni syndrome and bear germline mutations in TP53...

  20. The human ARF tumor suppressor senses blastema activity and suppresses epimorphic tissue regeneration

    Science.gov (United States)

    Hesse, Robert G; Kouklis, Gayle K; Ahituv, Nadav; Pomerantz, Jason H

    2015-01-01

    The control of proliferation and differentiation by tumor suppressor genes suggests that evolution of divergent tumor suppressor repertoires could influence species’ regenerative capacity. To directly test that premise, we humanized the zebrafish p53 pathway by introducing regulatory and coding sequences of the human tumor suppressor ARF into the zebrafish genome. ARF was dormant during development, in uninjured adult fins, and during wound healing, but was highly expressed in the blastema during epimorphic fin regeneration after amputation. Regenerative, but not developmental signals resulted in binding of zebrafish E2f to the human ARF promoter and activated conserved ARF-dependent Tp53 functions. The context-dependent activation of ARF did not affect growth and development but inhibited regeneration, an unexpected distinct tumor suppressor response to regenerative versus developmental environments. The antagonistic pleiotropic characteristics of ARF as both tumor and regeneration suppressor imply that inducing epimorphic regeneration clinically would require modulation of ARF –p53 axis activation. DOI: http://dx.doi.org/10.7554/eLife.07702.001 PMID:26575287

  1. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Heyu [Central Laboratory, Peking University School of Stomatology, Beijing (China); Nan, Xu [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Xuefen [Central Laboratory, Peking University School of Stomatology, Beijing (China); Chen, Yan; Zhang, Jianyun [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China); Sun, Lisha [Central Laboratory, Peking University School of Stomatology, Beijing (China); Han, Wenlin [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Tiejun, E-mail: litiejun22@vip.sina.com [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China)

    2014-05-02

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.

  2. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhang, Heyu; Nan, Xu; Li, Xuefen; Chen, Yan; Zhang, Jianyun; Sun, Lisha; Han, Wenlin; Li, Tiejun

    2014-01-01

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma

  3. High-level HIV-1 Nef transient expression in Nicotiana benthamiana using the P19 gene silencing suppressor protein of Artichoke Mottled Crinckle Virus

    Directory of Open Access Journals (Sweden)

    Bianco Linda

    2009-11-01

    Full Text Available Abstract Background In recent years, different HIV antigens have been successfully expressed in plants by either stable transformation or transient expression systems. Among HIV proteins, Nef is considered a promising target for the formulation of a multi-component vaccine due to its implication in the first steps of viral infection. Attempts to express Nef as a single protein product (not fused to a stabilizing protein in transgenic plants resulted in disappointingly low yields (about 0.5% of total soluble protein. In this work we describe a transient expression system based on co-agroinfiltration of plant virus gene silencing suppressor proteins in Nicotiana benthamiana, followed by a two-step affinity purification protocol of plant-derived Nef. Results The effect of three gene silencing viral suppressor proteins (P25 of Potato Virus X, P19 of either Artichoke Mottled Crinckle virus and Tomato Bushy Stunt virus on Nef transient expression yield was evaluated. The P19 protein of Artichoke Mottled Crinckle virus (AMCV-P19 gave the highest expression yield in vacuum co-agroinfiltration experiments reaching 1.3% of total soluble protein, a level almost three times higher than that previously reported in stable transgenic plants. The high yield observed in the co-agroinfiltrated plants was correlated to a remarkable decrease of Nef-specific small interfering RNAs (siRNAs indicating an effective modulation of RNA silencing mechanisms by AMCV-P19. Interestingly, we also showed that expression levels in top leaves of vacuum co-agroinfiltrated plants were noticeably reduced compared to bottom leaves. Moreover, purification of Nef from agroinfiltrated tissue was achieved by a two-step immobilized metal ion affinity chromatography protocol with yields of 250 ng/g of fresh tissue. Conclusion We demonstrated that expression level of HIV-1 Nef in plant can be improved using a transient expression system enhanced by the AMCV-P19 gene silencing suppressor

  4. The tumor suppressors p33ING1 and p33ING2 interact with alien in vivo and enhance alien-mediated gene silencing.

    Science.gov (United States)

    Fegers, Inga; Kob, Robert; Eckey, Maren; Schmidt, Oliver; Goeman, Frauke; Papaioannou, Maria; Escher, Niko; von Eggeling, Ferdinand; Melle, Christian; Baniahmad, Aria

    2007-11-01

    The tumor suppressor p33ING1 is involved in DNA repair and cell cycle regulation. Furthermore, p33ING1 is a transcriptional silencer that recognizes the histone mark for trimethylated lysine 4 at histone H3. Interestingly, expression of p33ING1 and p33ING2 is able to induce premature senescence in primary human fibroblasts. The corepressor Alien is involved in gene silencing mediated by selected members of nuclear hormone receptors. In addition, Alien acts as a corepressor for E2F1, a member of the E2F cell cycle regulatory family. Furthermore, recent findings suggest that Alien is complexed with transcription factors participating in DNA repair and chromatin. Here, using a proteomic approach by surface-enhanced laser desorption ionization and mass spectrometry (SELDI-MS) combined with immunological techniques, we show that Alien interacts in vivo with the tumor suppressor p33ING1 as well as with the related tumor suppressor candidate p33ING2. The interaction of Alien with p33ING1 and p33ING2 was confirmed in vitro with GST-pull-down, suggesting a direct binding of Alien to these factors. The binding domain was mapped to a central region of Alien. Functionally, the expression of p33ING1 or p33ING2 enhances the Alien-mediated silencing, suggesting that the interaction plays a role in transcriptional regulation. Thus, the findings suggest that the identified interaction between Alien and the tumor suppressors p33ING1 and p33ING2 reveals a novel cellular protein network.

  5. The essential Escherichia coli msgB gene, a multicopy suppressor of a temperature-sensitive allele of the heat shock gene grpE, is identical to dapE.

    OpenAIRE

    Wu, B; Georgopoulos, C; Ang, D

    1992-01-01

    The grpE gene product is one of three Escherichia coli heat shock proteins (DnaK, DnaJ, and GrpE) that are essential for both bacteriophage lambda DNA replication and bacterial growth at all temperatures. In an effort to determine the role of GrpE and to identify other factors that it may interact with, we isolated multicopy suppressors of the grpE280 point mutation, as judged by their ability to reverse the temperature-sensitive phenotype of grpE280. Here we report the characterization of on...

  6. Proto-oncogene FBI-1 (Pokemon/ZBTB7A) Represses Transcription of the Tumor Suppressor Rb Gene via Binding Competition with Sp1 and Recruitment of Co-repressors*S⃞

    Science.gov (United States)

    Jeon, Bu-Nam; Yoo, Jung-Yoon; Choi, Won-Il; Lee, Choong-Eun; Yoon, Ho-Geun; Hur, Man-Wook

    2008-01-01

    FBI-1 (also called Pokemon/ZBTB7A) is a BTB/POZ-domain Krüppel-like zinc-finger transcription factor. Recently, FBI-1 was characterized as a proto-oncogenic protein, which represses tumor suppressor ARF gene transcription. The expression of FBI-1 is increased in many cancer tissues. We found that FBI-1 potently represses transcription of the Rb gene, a tumor suppressor gene important in cell cycle arrest. FBI-1 binds to four GC-rich promoter elements (FREs) located at bp –308 to –188 of the Rb promoter region. The Rb promoter also contains two Sp1 binding sites: GC-box 1 (bp –65 to –56) and GC-box 2 (bp –18 to –9), the latter of which is also bound by FBI-1. We found that FRE3 (bp –244 to –236) is also a Sp1 binding element. FBI-1 represses transcription of the Rb gene not only by binding to the FREs, but also by competing with Sp1 at the GC-box 2 and the FRE3. By binding to the FREs and/or the GC-box, FBI-1 represses transcription of the Rb gene through its POZ-domain, which recruits a co-repressor-histone deacetylase complex and deacetylates histones H3 and H4 at the Rb gene promoter. FBI-1 inhibits C2C12 myoblast cell differentiation by repressing Rb gene expression. PMID:18801742

  7. A phase I study of hydralazine to demethylate and reactivate the expression of tumor suppressor genes

    International Nuclear Information System (INIS)

    Zambrano, Pilar; Sandoval, Karina; Trejo-Becerril, Catalina; Chanona-Vilchis, Jose; Duenas-González, Alfonso; Segura-Pacheco, Blanca; Perez-Cardenas, Enrique; Cetina, Lucely; Revilla-Vazquez, Alma; Taja-Chayeb, Lucía; Chavez-Blanco, Alma; Angeles, Enrique; Cabrera, Gustavo

    2005-01-01

    The antihypertensive compound hydralazine is a known demethylating agent. This phase I study evaluated the tolerability and its effects upon DNA methylation and gene reactivation in patients with untreated cervical cancer. Hydralazine was administered to cohorts of 4 patients at the following dose levels: I) 50 mg/day, II) 75 mg/day, III) 100 mg/day and IV) 150 mg/day. Tumor biopsies and peripheral blood samples were taken the day before and after treatment. The genes APC, MGMT; ER, GSTP1, DAPK, RARβ, FHIT and p16 were evaluated pre and post-treatment for DNA promoter methylation and gene expression by MSP (Methylation-Specific PCR) and RT-PCR respectively in each of the tumor samples. Methylation of the imprinted H19 gene and the 'normally methylated' sequence clone 1.2 was also analyzed. Global DNA methylation was analyzed by capillary electrophoresis and cytosine extension assay. Toxicity was evaluated using the NCI Common Toxicity Criteria. Hydralazine was well tolerated. Toxicities were mild being the most common nausea, dizziness, fatigue, headache and palpitations. Overall, 70% of the pretreatment samples and all the patients had at least one methylated gene. Rates of demethylation at the different dose levels were as follows: 50 mg/day, 40%; 75 mg/day, 52%, 100 mg/day, 43%, and 150 mg/day, 32%. Gene expression analysis showed only 12 informative cases, of these 9 (75%) re-expressed the gene. There was neither change in the methylation status of H19 and clone 1.2 nor changes in global DNA methylation. Hydralazine at doses between 50 and 150 mg/day is well tolerated and effective to demethylate and reactivate the expression of tumor suppressor genes without affecting global DNA methylation

  8. Homozygous deletion of the α- and β1-interferon genes in human leukemia and derived cell lines

    International Nuclear Information System (INIS)

    Diaz, M.O.; Ziemin, S.; Le Beau, M.M.; Pitha, P.; Smith, S.D.; Chilcote, R.R.; Rowley, J.D.

    1988-01-01

    The loss of bands p21-22 from one chromosome 9 homologue as a consequence of a deletion of the short arm [del(9p)], unbalanced translocation, or monosomy 9 is frequently observed in the malignant cells of patients with lymphoid neoplasias, including acute lymphoblastic leukemia and non-Hodgkin lymphoma. The α- and β 1 -interferon genes have been assigned to this chromosome region (9p21-22). The authors now present evidence of the homozygous deletion of the interferon genes in neoplastic hematopoietic cell lines and primary leukemia cells in the presence or absence of chromosomal deletions that are detectable at the level of the light microscope. In these cell lines, the deletion of the interferon genes is accompanied by a deficiency of 5'-methylthioadenosine phosphorylase, an enzyme of purine metabolism. These homozygous deletions may be associated with the loss of a tumor-suppressor gene that is involved in the development of these neoplasias. The relevant genes may be either the interferon genes themselves or a gene that has a tumor-suppressor function and is closely linked to them

  9. Loss of heterozygosity at 9q33 and hypermethylation of the DBCCR1 gene in oral squamous cell carcinoma

    DEFF Research Database (Denmark)

    Gao, S.; Worm, J.; Guldberg, P.

    2004-01-01

    The DBCCR1 gene at chromosome 9q33 has been identified as a candidate tumour suppressor, which is frequently targeted by promoter hypermethylation in bladder cancer. Here, we studied the possible involvement of DBCCR1 in the development of oral squamous cell carcinoma. DNA from 34 tumours...

  10. PHTS, a novel putative tumor suppressor, is involved in the transformation reversion of HeLaHF cells independently of the p53 pathway

    International Nuclear Information System (INIS)

    Yu Dehua; Fan, Wufang; Liu, Guohong; Nguy, Vivian; Chatterton, Jon E.; Long Shilong; Ke, Ning; Meyhack, Bernd; Bruengger, Adrian; Brachat, Arndt; Wong-Staal, Flossie; Li, Qi-Xiang

    2006-01-01

    HeLaHF is a non-transformed revertant of HeLa cells, likely resulting from the activation of a putative tumor suppressor(s). p53 protein was stabilized in this revertant and reactivated for certain transactivation functions. Although p53 stabilization has not conclusively been linked to the reversion, it is clear that the genes in p53 pathway are involved. The present study confirms the direct role of p53 in HeLaHF reversion by demonstrating that RNAi-mediated p53 silencing partially restores anchorage-independent growth potential of the revertant through the suppression of anoikis. In addition, we identified a novel gene, named PHTS, with putative tumor suppressor properties, and showed that this gene is also involved in HeLaHF reversion independently of the p53 pathway. Expression profiling revealed that PHTS is one of the genes that is up-regulated in HeLaHF but not in HeLa. It encodes a putative protein with CD59-like domains. RNAi-mediated PHTS silencing resulted in the partial restoration of transformation (anchorage-independent growth) in HeLaHF cells, similar to that of p53 gene silencing, implying its tumor suppressor effect. However, the observed increased transformation potential by PHTS silencing appears to be due to an increased anchorage-independent proliferation rate rather than suppression of anoikis, unlike the effect of p53 silencing. p53 silencing did not affect PHTS gene expression, and vice versa, suggesting PHTS may function in a new and p53-independent tumor suppressor pathway. Furthermore, over-expression of PHTS in different cancer cell lines, in addition to HeLa, reduces cell growth likely via induced apoptosis, confirming the broad PHTS tumor suppressor properties

  11. Genome-wide analysis of histone H3 acetylation patterns in AML identifies PRDX2 as an epigenetically silenced tumor suppressor gene

    DEFF Research Database (Denmark)

    Agrawal-Singh, Shuchi; Isken, Fabienne; Agelopoulos, Konstantin

    2012-01-01

    to have lower H3Ac levels in AML compared with progenitor cells, which suggested that a large number of genes are epigenetically silenced in AML. Intriguingly, we identified peroxiredoxin 2 (PRDX2) as a novel potential tumor suppressor gene in AML. H3Ac was decreased at the PRDX2 gene promoter in AML......With the use of ChIP on microarray assays in primary leukemia samples, we report that acute myeloid leukemia (AML) blasts exhibit significant alterations in histone H3 acetylation (H3Ac) levels at > 1000 genomic loci compared with CD34+ progenitor cells. Importantly, core promoter regions tended......, which correlated with low mRNA and protein expression. We also observed DNA hypermethylation at the PRDX2 promoter in AML. Low protein expression of the antioxidant PRDX2 gene was clinically associated with poor prognosis in patients with AML. Functionally, PRDX2 acted as inhibitor of myeloid cell...

  12. Primary microcephaly gene MCPH1 shows signatures of tumor suppressors and is regulated by miR-27a in oral squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Thejaswini Venkatesh

    Full Text Available Mutations in the MCPH1 (microcephalin 1 gene, located at chromosome 8p23.1, result in two autosomal recessive disorders: primary microcephaly and premature chromosome condensation syndrome. MCPH1 has also been shown to be downregulated in breast, prostate and ovarian cancers, and mutated in 1/10 breast and 5/41 endometrial tumors, suggesting that it could also function as a tumor suppressor (TS gene. To test the possibility of MCPH1 as a TS gene, we first performed LOH study in a panel of 81 matched normal oral tissues and oral squamous cell carcinoma (OSCC samples, and observed that 14/71 (19.72% informative samples showed LOH, a hallmark of TS genes. Three protein truncating mutations were identified in 1/15 OSCC samples and 2/5 cancer cell lines. MCPH1 was downregulated at both the transcript and protein levels in 21/41 (51.22% and 19/25 (76% OSCC samples respectively. A low level of MCPH1 promoter methylation was also observed in 4/40 (10% tumor samples. We further observed that overexpression of MCPH1 decreased cellular proliferation, anchorage-independent growth in soft agar, cell invasion and tumor size in nude mice, indicating its tumor suppressive function. Using bioinformatic approaches and luciferase assay, we showed that the 3'-UTR of MCPH1 harbors two non-overlapping functional seed regions for miR-27a which negatively regulated its level. The expression level of miR-27a negatively correlated with the MCPH1 protein level in OSCC. Our study indicates for the first time that, in addition to its role in brain development, MCPH1 also functions as a tumor suppressor gene and is regulated by miR-27a.

  13. Tumor Suppressor Activity of the EphB2 Receptor in Prostate Cancer

    National Research Council Canada - National Science Library

    Pasquale, Elena B

    2007-01-01

    Mutations have been recently identified in the EphB2 receptor gene in prostate cancer suggesting that EphB2, a member of the large Eph receptor tyrosine kinase family, is a tumor suppressor in prostate cancer...

  14. Tumor Suppressor Activity of the EphB2 Receptor in Prostate Cancer

    National Research Council Canada - National Science Library

    Pasquale, Elena B

    2006-01-01

    Mutations have been recently identified in the EphB2 receptor gene in prostate cancer suggesting that EphB2, a member of the large Eph receptor tyrosine kinase family, is a tumor suppressor in prostate cancer...

  15. Quantitative Methylation Profiles for Multiple Tumor Suppressor Gene Promoters in Salivary Gland Tumors

    Science.gov (United States)

    Durr, Megan L.; Mydlarz, Wojciech K.; Shao, Chunbo; Zahurak, Marianna L.; Chuang, Alice Y.; Hoque, Mohammad O.; Westra, William H.; Liegeois, Nanette J.; Califano, Joseph A.; Sidransky, David; Ha, Patrick K.

    2010-01-01

    Background Methylation profiling of tumor suppressor gene (TSGs) promoters is quickly becoming a powerful diagnostic tool for the early detection, prognosis, and even prediction of clinical response to treatment. Few studies address this in salivary gland tumors (SGTs); hence the promoter methylation profile of various TSGs was quantitatively assessed in primary SGT tissue to determine if tumor-specific alterations could be detected. Methodology DNA isolated from 78 tumor and 17 normal parotid gland specimens was assayed for promoter methylation status of 19 TSGs by fluorescence-based, quantitative methylation-specific PCR (qMSP). The data were utilized in a binary fashion as well as quantitatively (using a methylation quotient) allowing for better profiling and interpretation of results. Principal Findings The average number of methylation events across the studied genes was highest in salivary duct carcinoma (SDC), with a methylation value of 9.6, compared to the normal 4.5 (ptrend for increasing methylation in APC, Mint 1, PGP9.5, RAR-β, and Timp3. Conclusions/Significance Screening promoter methylation profiles in SGTs showed considerable heterogeneity. The methylation status of certain markers was surprisingly high in even normal salivary tissue, confirming the need for such controls. Several TSGs were found to be associated with malignant SGTs, especially SDC. Further study is needed to evaluate the potential use of these associations in the detection, prognosis, and therapeutic outcome of these rare tumors. PMID:20520817

  16. Is the gene encoding Chibby implicated as a tumour suppressor in colorectal cancer ?

    International Nuclear Information System (INIS)

    Gad, Sophie; Teboul, David; Lièvre, Astrid; Goasguen, Nicolas; Berger, Anne; Beaune, Philippe; Laurent-Puig, Pierre

    2004-01-01

    A novel member of the Wnt signalling pathway, Chibby, was recently identified. This protein inhibits Wnt/β-catenin mediated transcriptional activation by competing with Lef-1 (the transcription factor and target of β-catenin) to bind to β-catenin. This suggests that Chibby could be a tumour suppressor protein. The C22orf2 gene coding Chibby is located on chromosome 22, a region recurrently lost in colorectal cancer. Activation of the Wnt pathway is a major feature of colorectal cancer and occurs through inactivation of APC or activation of β-catenin. All of this led us to analyse the possible implication of Chibby in colorectal carcinogenesis. First, 36 tumour and matched normal colonic mucosa DNA were genotyped with five microsatellite markers located on chromosome 22 to search for loss of heterozygosity. Then, mutation screening of the C22orf2 coding sequence and splice sites was performed in the 36 tumour DNA. Finally, expression of Chibby was analysed by quantitative RT-PCR on 10 patients, 4 with loss of heterozygosity (LOH) on chromosome 22. Loss of heterozygosity involving the C22orf2 region was detected in 11 out of 36 patients (30%). Sequencing analysis revealed a known variant, rs3747174, in exon 5: T321C leading to a silent amino acid polymorphism A107A. Allelic frequencies were 0.69 and 0.31 for T and C variants respectively. No other mutation was detected. Among the 10 patients studied, expression analysis revealed that Chibby is overexpressed in 2 tumours and underexpressed in 1. No correlations were found with 22q LOH status. As no somatic mutation was detected in C22orf2 in 36 colorectal tumour DNA, our results do not support the implication of Chibby as a tumour suppressor in colorectal carcinogenesis. This was supported by the absence of underexpression of Chibby among the tumour samples with 22q LOH. The implication of other Wnt pathway members remains to be identified to explain the part of colorectal tumours without mutation in APC and β-catenin

  17. Identification and Characterization of Genes That Interact with Lin-12 in Caenorhabditis Elegans

    OpenAIRE

    Tax, F. E.; Thomas, J. H.; Ferguson, E. L.; Horvitz, H. R.

    1997-01-01

    We identified and characterized 14 extragenic mutations that suppressed the dominant egg-laying defect of certain lin-12 gain-of-function mutations. These suppressors defined seven genes: sup-17, lag-2, sel-4, sel-5, sel-6, sel-7 and sel-8. Mutations in six of the genes are recessive suppressors, whereas the two mutations that define the seventh gene, lag-2, are semi-dominant suppressors. These suppressor mutations were able to suppress other lin-12 gain-of-function mutations. The suppressor ...

  18. Physical mapping of chromosome 17p13.3 in the region of a putative tumor suppressor gene important in medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, J.D.; Daneshvar, L.; Willert, J.R. [Univ. of California, San Franciso, CA (United States)] [and others

    1994-09-01

    Deletion mapping of a medulloblastoma tumor panel revealed loss of distal chromosome 17p13.3 sequences in tumors from 14 of 32 patients (44%). Of the 14 tumors showing loss of heterozygosity by restriction fragment length polymorphism analysis, 14 of 14 (100%) displayed loss of the telomeric marker p144-D6 (D17S34), while a probe for the ABR gene on 17p13.3 was lost in 7 of 8 (88%) informative cases. Using pulsed-field gel electrophoresis, we localized the polymorphic marker (VNTR-A) of the ABR gene locus to within 220 kb of the p144-D6 locus. A cosmid contig constructed in this region was used to demonstrate by fluorescence in situ hybridization that the ABR gene is oriented transcriptionally 5{prime} to 3{prime} toward the telomere. This report provides new physical mapping data for the ABR gene, which has not been previously shown to be deleted in medulloblastoma. These results provide further evidence for the existence of a second tumor suppressor gene distinct from p53 on distal chromosome 17p. 12 refs., 3 figs.

  19. Human microRNA oncogenes and tumor suppressors show significantly different biological patterns: from functions to targets.

    Directory of Open Access Journals (Sweden)

    Dong Wang

    Full Text Available MicroRNAs (miRNAs are small noncoding RNAs which play essential roles in many important biological processes. Therefore, their dysfunction is associated with a variety of human diseases, including cancer. Increasing evidence shows that miRNAs can act as oncogenes or tumor suppressors, and although there is great interest in research into these cancer-associated miRNAs, little is known about them. In this study, we performed a comprehensive analysis of putative human miRNA oncogenes and tumor suppressors. We found that miRNA oncogenes and tumor suppressors clearly show different patterns in function, evolutionary rate, expression, chromosome distribution, molecule size, free energy, transcription factors, and targets. For example, miRNA oncogenes are located mainly in the amplified regions in human cancers, whereas miRNA tumor suppressors are located mainly in the deleted regions. miRNA oncogenes tend to cleave target mRNAs more frequently than miRNA tumor suppressors. These results indicate that these two types of cancer-associated miRNAs play different roles in cancer formation and development. Moreover, the patterns identified here can discriminate novel miRNA oncogenes and tumor suppressors with a high degree of accuracy. This study represents the first large-scale bioinformatic analysis of human miRNA oncogenes and tumor suppressors. Our findings provide help for not only understanding of miRNAs in cancer but also for the specific identification of novel miRNAs as miRNA oncogenes and tumor suppressors. In addition, the data presented in this study will be valuable for the study of both miRNAs and cancer.

  20. Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

    OpenAIRE

    Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

    1992-01-01

    Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-...

  1. Tumor suppressor genes that escape from X-inactivation contribute to cancer sex bias

    Science.gov (United States)

    Dunford, Andrew; Weinstock, David M.; Savova, Virginia; Schumacher, Steven E.; Cleary, John P.; Yoda, Akinori; Sullivan, Timothy J.; Hess, Julian M.; Gimelbrant, Alexander A.; Beroukhim, Rameen; Lawrence, Michael S.; Getz, Gad; Lane, Andrew A.

    2016-01-01

    There is a striking and unexplained male predominance across many cancer types. A subset of X chromosome (chrX) genes can escape X-inactivation, which would protect females from complete functional loss by a single mutation. To identify putative “Escape from X-Inactivation Tumor Suppressor” (EXITS) genes, we compared somatic alterations from >4100 cancers across 21 tumor types for sex bias. Six of 783 non-pseudoautosomal region (PAR) chrX genes (ATRX, CNKSR2, DDX3X, KDM5C, KDM6A, and MAGEC3) more frequently harbored loss-of-function mutations in males (based on false discovery rate <0.1), compared to zero of 18,055 autosomal and PAR genes (P<0.0001). Male-biased mutations in genes that escape X-inactivation were observed in combined analysis across many cancers and in several individual tumor types, suggesting a generalized phenomenon. We conclude that biallelic expression of EXITS genes in females explains a portion of the reduced cancer incidence compared to males across a variety of tumor types. PMID:27869828

  2. A Tumor Suppressor Gene Product, Platelet-Derived Growth Factor Receptor-Like Protein Controls Chondrocyte Proliferation and Differentiation.

    Science.gov (United States)

    Kawata, Kazumi; Kubota, Satoshi; Eguchi, Takanori; Aoyama, Eriko; Moritani, Norifumi H; Oka, Morihiko; Kawaki, Harumi; Takigawa, Masaharu

    2017-11-01

    The platelet-derived growth factor receptor-like (PDGFRL) gene is regarded as a tumor suppressor gene. However, nothing is known about the molecular function of PDGFRL. In this study, we initially clarified its function in chondrocytes. Among all cell lines examined, the PDGFRL mRNA level was the highest in chondrocytic HCS-2/8 cells. Interestingly, the proliferation of chondrocytic HCS-2/8 cells was promoted by PDGFRL overexpression, whereas that of the breast cancer-derived MDA-MB-231 cells was inhibited. Of note, in PDGFRL-overexpressing HCS-2/8 cells, the expression of chondrocyte differentiation marker genes, SOX9, ACAN, COL2A1, COL10A1, and ALP, was decreased. Moreover, we confirmed the expression of PDGFRL mRNA in normal cartilage tissue and chondrocytes. Eventually, the expression of PDGFRL mRNA in condrocytes except in the case of hypertrophic chondrocytes was demonstrated in vivo and in vitro. These findings suggest that PDGFRL plays the different roles, depending upon cell types. Particularly, in chondrocytes, PDGFRL may play a new and important role which is distinct from the function previously reported. J. Cell. Biochem. 118: 4033-4044, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Frequent down-regulation of ABC transporter genes in prostate cancer

    International Nuclear Information System (INIS)

    Demidenko, Rita; Razanauskas, Deividas; Daniunaite, Kristina; Lazutka, Juozas Rimantas; Jankevicius, Feliksas; Jarmalaite, Sonata

    2015-01-01

    ATP-binding cassette (ABC) transporters are transmembrane proteins responsible for the efflux of a wide variety of substrates, including steroid metabolites, through the cellular membranes. For better characterization of the role of ABC transporters in prostate cancer (PCa) development, the profile of ABC transporter gene expression was analyzed in PCa and noncancerous prostate tissues (NPT). TaqMan Low Density Array (TLDA) human ABC transporter plates were used for the gene expression profiling in 10 PCa and 6 NPT specimens. ABCB1 transcript level was evaluated in a larger set of PCa cases (N = 78) and NPT (N = 15) by real-time PCR, the same PCa cases were assessed for the gene promoter hypermethylation by methylation-specific PCR. Expression of eight ABC transporter genes (ABCA8, ABCB1, ABCC6, ABCC9, ABCC10, ABCD2, ABCG2, and ABCG4) was significantly down-regulated in PCa as compared to NPT, and only two genes (ABCC4 and ABCG1) were up-regulated. Down-regulation of ABC transporter genes was prevalent in the TMPRSS2-ERG-negative cases. A detailed analysis of ABCB1 expression confirmed TLDA results: a reduced level of the transcript was identified in PCa in comparison to NPT (p = 0.048). Moreover, the TMPRSS2-ERG-negative PCa cases showed significantly lower expression of ABCB1 in comparison to NPT (p = 0.003) or the fusion-positive tumors (p = 0.002). Promoter methylation of ABCB1 predominantly occurred in PCa and was rarely detected in NPT (p < 0.001). The study suggests frequent down-regulation of the ABC transporter genes in PCa, especially in the TMPRSS2-ERG-negative tumors. The online version of this article (doi:10.1186/s12885-015-1689-8) contains supplementary material, which is available to authorized users

  4. The tumor suppressor gene TRC8/RNF139 is disrupted by a constitutional balanced translocation t(8;22(q24.13;q11.21 in a young girl with dysgerminoma

    Directory of Open Access Journals (Sweden)

    Fiorio Patrizia

    2009-07-01

    Full Text Available Abstract Background RNF139/TRC8 is a potential tumor suppressor gene with similarity to PTCH, a tumor suppressor implicated in basal cell carcinomas and glioblastomas. TRC8 has the potential to act in a novel regulatory relationship linking the cholesterol/lipid biosynthetic pathway with cellular growth control and has been identified in families with hereditary renal (RCC and thyroid cancers. Haploinsufficiency of TRC8 may facilitate development of clear cell-RCC in association with VHL mutations, and may increase risk for other tumor types. We report a paternally inherited balanced translocation t(8;22 in a proposita with dysgerminoma. Methods The translocation was characterized by FISH and the breakpoints cloned, sequenced, and compared. DNA isolated from normal and tumor cells was checked for abnormalities by array-CGH. Expression of genes TRC8 and TSN was tested both on dysgerminoma and in the proposita and her father. Results The breakpoints of the translocation are located within the LCR-B low copy repeat on chromosome 22q11.21, containing the palindromic AT-rich repeat (PATRR involved in recurrent and non-recurrent translocations, and in an AT-rich sequence inside intron 1 of the TRC8 tumor-suppressor gene at 8q24.13. TRC8 was strongly underexpressed in the dysgerminoma. Translin is underexpressed in the dysgerminoma compared to normal ovary. TRC8 is a target of Translin (TSN, a posttranscriptional regulator of genes transcribed by the transcription factor CREM-tau in postmeiotic male germ cells. Conclusion A role for TRC8 in dysgerminoma may relate to its interaction with Translin. We propose a model in which one copy of TRC8 is disrupted by a palindrome-mediated translocation followed by complete loss of expression through suppression, possibly mediated by miRNA.

  5. Ring structure amino acids affect the suppressor activity of melon aphid-borne yellows virus P0 protein.

    Science.gov (United States)

    Han, Yan-Hong; Xiang, Hai-Ying; Wang, Qian; Li, Yuan-Yuan; Wu, Wen-Qi; Han, Cheng-Gui; Li, Da-Wei; Yu, Jia-Lin

    2010-10-10

    Melon aphid-borne yellows virus (MABYV) is a newly identified polerovirus occurring in China. Here, we demonstrate that the MABYV encoded P0 (P0(MA)) protein is a strong suppressor of post-transcriptional gene silencing (PTGS) with activity comparable to tobacco etch virus (TEV) HC-Pro. In addition we have shown that the LP F-box motif present at the N-terminus of P0(MA) is required for suppressor activity. Detailed mutational analyses on P0(MA) revealed that changing the conserved Trp 212 with non-ring structured amino acids altered silencing suppressor functions. Ala substitutions at positions 12 and 211 for Phe had no effect on P0 suppression-activity, whereas Arg and Glu substitutions had greatly decreased suppressor activity. Furthermore, substitutions targeting Phe at position 30 also resulted in reduced P0 suppression-activity. Altogether, these results suggest that ring structured Trp/Phe residues in P0 have important roles in suppressor activity. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Evolution and origin of merlin, the product of the Neurofibromatosis type 2 (NF2 tumor-suppressor gene

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    Omelyanchuk Leonid V

    2005-12-01

    Full Text Available Abstract Background Merlin, the product of the Neurofibromatosis type 2 (NF2 tumor suppressor gene, belongs to the ezrin-radixin-moesin (ERM subgroup of the protein 4.1 superfamily, which links cell surface glycoproteins to the actin cytoskeleton. While merlin's functional activity has been examined in mammalian and Drosophila models, little is understood about its evolution, diversity, and overall distribution among different taxa. Results By combining bioinformatic and phylogenetic approaches, we demonstrate that merlin homologs are present across a wide range of metazoan lineages. While the phylogenetic tree shows a monophyletic origin of the ERM family, the origin of the merlin proteins is robustly separated from that of the ERM proteins. The derivation of merlin is thought to be in early metazoa. We have also observed the expansion of the ERM-like proteins within the vertebrate clade, which occurred after its separation from Urochordata (Ciona intestinalis. Amino acid sequence alignment reveals the absence of an actin-binding site in the C-terminal region of all merlin proteins from various species but the presence of a conserved internal binding site in the N-terminal domain of the merlin and ERM proteins. In addition, a more conserved pattern of amino acid residues is found in the region containing the so-called "Blue Box," although some amino acid substitutions in this region exist in the merlin sequences of worms, fish, and Ciona. Examination of sequence variability at functionally significant sites, including the serine-518 residue, the phosphorylation of which modulates merlin's intra-molecular association and function as a tumor suppressor, identifies several potentially important sites that are conserved among all merlin proteins but divergent in the ERM proteins. Secondary structure prediction reveals the presence of a conserved α-helical domain in the central to C-terminal region of the merlin proteins of various species. The

  7. Frequent amplification of CENPF, GMNN and CDK13 genes in hepatocellular carcinomas.

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    Hye-Eun Kim

    Full Text Available Genomic changes frequently occur in cancer cells during tumorigenesis from normal cells. Using the Illumina Human NS-12 single-nucleotide polymorphism (SNP chip to screen for gene copy number changes in primary hepatocellular carcinomas (HCCs, we initially detected amplification of 35 genes from four genomic regions (1q21-41, 6p21.2-24.1, 7p13 and 8q13-23. By integrated screening of these genes for both DNA copy number and gene expression in HCC and colorectal cancer, we selected CENPF (centromere protein F/mitosin, GMNN (geminin, DNA replication inhibitor, CDK13 (cyclin-dependent kinase 13, and FAM82B (family with sequence similarity 82, member B as common cancer genes. Each gene exhibited an amplification frequency of ~30% (range, 20-50% in primary HCC (n = 57 and colorectal cancer (n = 12, as well as in a panel of human cancer cell lines (n = 70. Clonogenic and invasion assays of NIH3T3 cells transfected with each of the four amplified genes showed that CENPF, GMNN, and CDK13 were highly oncogenic whereas FAM82B was not. Interestingly, the oncogenic activity of these genes (excluding FAM82B was highly correlated with gene-copy numbers in tumor samples (correlation coefficient, r>0.423, indicating that amplifications of CENPF, GMNN, and CDK13 genes are tightly linked and coincident in tumors. Furthermore, we confirmed that CDK13 gene copy number was significantly associated with clinical onset age in patients with HCC (P = 0.0037. Taken together, our results suggest that coincidently amplified CDK13, GMNN, and CENPF genes can play a role as common cancer-driver genes in human cancers.

  8. Frequent mutations of genes encoding ubiquitin-mediated proteolysis pathway components in clear cell renal cell carcinoma

    DEFF Research Database (Denmark)

    Guo, Guangwu; Gui, Yaoting; Gao, Shengjie

    2012-01-01

    We sequenced whole exomes of ten clear cell renal cell carcinomas (ccRCCs) and performed a screen of similar to 1,100 genes in 88 additional ccRCCs, from which we discovered 12 previously unidentified genes mutated at elevated frequencies in ccRCC. Notably, we detected frequent mutations in the u...

  9. The role of tumor suppressor p15Ink4b in the regulation of hematopoietic progenitor cell fate

    International Nuclear Information System (INIS)

    Humeniuk, R; Rosu-Myles, M; Fares, J; Koller, R; Bies, J; Wolff, L

    2013-01-01

    Epigenetic silencing of the tumor suppressor gene p15Ink4b (CDKN2B) is a frequent event in blood disorders like acute myeloid leukemia and myelodysplastic syndromes. The molecular function of p15Ink4b in hematopoietic differentiation still remains to be elucidated. Our previous study demonstrated that loss of p15Ink4b in mice results in skewing of the differentiation pattern of the common myeloid progenitor towards the myeloid lineage. Here, we investigated a function of p15Ink4b tumor suppressor gene in driving erythroid lineage commitment in hematopoietic progenitors. It was found that p15Ink4b is expressed more highly in committed megakaryocyte–erythroid progenitors than granulocyte–macrophage progenitors. More importantly, mice lacking p15Ink4b have lower numbers of primitive red cell progenitors and a severely impaired response to 5-fluorouracil- and phenylhydrazine-induced hematopoietic stress. Introduction of p15Ink4b into multipotential progenitors produced changes at the molecular level, including activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) signaling, increase GATA-1, erythropoietin receptor (EpoR) and decrease Pu1, GATA-2 expression. These changes rendered cells more permissive to erythroid commitment and less permissive to myeloid commitment, as demonstrated by an increase in early burst-forming unit-erythroid formation with concomitant decrease in myeloid colonies. Our results indicate that p15Ink4b functions in hematopoiesis, by maintaining proper lineage commitment of progenitors and assisting in rapid red blood cells replenishment following stress

  10. Effects of emodin on the demethylation of tumor-suppressor genes in pancreatic cancer PANC-1 cells.

    Science.gov (United States)

    Zhang, Hao; Chen, Liang; Bu, He-Qi; Yu, Qing-Jiang; Jiang, Dan-Dan; Pan, Feng-Ping; Wang, Yu; Liu, Dian-Lei; Lin, Sheng-Zhang

    2015-06-01

    Emodin, a natural anthraquinone derivative isolated from Rheum palmatum, has been reported to inhibit the growth of pancreatic cancer cells through different modes of action; yet, the detailed mechanism remains unclear. In the present study, we hypothesized that emodin exerts its antitumor effect by participating in the regulation of the DNA methylation level. Our research showed that emodin inhibited the growth of pancreatic cancer PANC-1 cells in a dose- and time-dependent manner. Dot-blot results showed that 40 µM emodin significantly inhibited genomic 5 mC expression in the PANC-1 cells, and mRNA-Seq showed that different concentrations of emodin could alter the gene expression profile in the PANC-1 cells. BSP confirmed that the methylation levels of P16, RASSF1A and ppENK were decreased, while concomitantly the unmethylated status was increased. RT-PCR and western blotting results confirmed that the low expression or absence of expression of mRNA and protein in the PANC-1 cells was re-expressed following treatment with emodin. In conclusion, our study for the first time suggests that emodin inhibits pancreatic cancer cell growth, which may be related to the demethylation of tumor-suppressor genes. The related mechanism may be through the inhibition of methyltransferase expression.

  11. Identification of genes highly downregulated in pancreatic cancer through a meta-analysis of microarray datasets: implications for discovery of novel tumor-suppressor genes and therapeutic targets.

    Science.gov (United States)

    Goonesekere, Nalin C W; Andersen, Wyatt; Smith, Alex; Wang, Xiaosheng

    2018-02-01

    The lack of specific symptoms at early tumor stages, together with a high biological aggressiveness of the tumor contribute to the high mortality rate for pancreatic cancer (PC), which has a 5-year survival rate of about 7%. Recent failures of targeted therapies inhibiting kinase activity in clinical trials have highlighted the need for new approaches towards combating this deadly disease. In this study, we have identified genes that are significantly downregulated in PC, through a meta-analysis of large number of microarray datasets. We have used qRT-PCR to confirm the downregulation of selected genes in a panel of PC cell lines. This study has yielded several novel candidate tumor-suppressor genes (TSGs) including GNMT, CEL, PLA2G1B and SERPINI2. We highlight the role of GNMT, a methyl transferase associated with the methylation potential of the cell, and CEL, a lipase, as potential therapeutic targets. We have uncovered genetic links to risk factors associated with PC such as smoking and obesity. Genes important for patient survival and prognosis are also discussed, and we confirm the dysregulation of metabolic pathways previously observed in PC. While many of the genes downregulated in our dataset are associated with protein products normally produced by the pancreas for excretion, we have uncovered some genes whose downregulation appear to play a more causal role in PC. These genes will assist in providing a better understanding of the disease etiology of PC, and in the search for new therapeutic targets and biomarkers.

  12. Posttranscriptional Regulation of the Neurofibromatosis 2 Gene

    Science.gov (United States)

    2006-07-01

    signaling and division were downregulated, including an apoptosis - related, putative tumor suppressor gene, LUCA-15, which was downregulated in seven of... embryologically from the outgrowth of the developing brain (Martinez-Morales et al., 2004). It is comprised of two major layers, the inner layer (prospective...eight genes involved with cell signaling and division were down- regulated. These include an apoptosis -related, putative tumor suppressor gene LUCA-15

  13. Dissecting epigenetic silencing complexity in the mouse lung cancer suppressor gene Cadm1.

    Directory of Open Access Journals (Sweden)

    Stella Marie Reamon-Buettner

    Full Text Available Disease-oriented functional analysis of epigenetic factors and their regulatory mechanisms in aberrant silencing is a prerequisite for better diagnostics and therapy. Yet, the precise mechanisms are still unclear and complex, involving the interplay of several effectors including nucleosome positioning, DNA methylation, histone variants and histone modifications. We investigated the epigenetic silencing complexity in the tumor suppressor gene Cadm1 in mouse lung cancer progenitor cell lines, exhibiting promoter hypermethylation associated with transcriptional repression, but mostly unresponsive to demethylating drug treatments. After predicting nucleosome positions and transcription factor binding sites along the Cadm1 promoter, we carried out single-molecule mapping with DNA methyltransferase M.SssI, which revealed in silent promoters high nucleosome occupancy and occlusion of transcription factor binding sites. Furthermore, M.SssI maps of promoters varied within and among the different lung cancer cell lines. Chromatin analysis with micrococcal nuclease also indicated variations in nucleosome positioning to have implications in the binding of transcription factors near nucleosome borders. Chromatin immunoprecipitation showed that histone variants (H2A.Z and H3.3, and opposing histone modification marks (H3K4me3 and H3K27me3 all colocalized in the same nucleosome positions that is reminiscent of epigenetic plasticity in embryonic stem cells. Altogether, epigenetic silencing complexity in the promoter region of Cadm1 is not only defined by DNA hypermethylation, but high nucleosome occupancy, altered nucleosome positioning, and 'bivalent' histone modifications, also likely contributed in the transcriptional repression of this gene in the lung cancer cells. Our results will help define therapeutic intervention strategies using epigenetic drugs in lung cancer.

  14. Are there tumor suppressor genes on chromosome 4p in sporadic colorectal carcinoma?

    Science.gov (United States)

    Zheng, Hai-Tao; Jiang, Li-Xin; Lv, Zhong-Chuan; Li, Da-Peng; Zhou, Chong-Zhi; Gao, Jian-Jun; He, Lin; Peng, Zhi-Hai

    2008-01-07

    To study the candidate tumor suppressor genes (TSG) on chromosome 4p by detecting the high frequency of loss of heterozygosity (LOH) in sporadic colorectal carcinoma in Chinese patients. Seven fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by PCR. PCR products were electrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. The same procedure was performed by the other six microsatellite markers spanning D4S3013 locus to make further detailed deletion mapping. Comparison between LOH frequency and clinicopathological factors was performed by c2 test. Data were collected from all informative loci. The average LOH frequency on 4p was 24.25%, and 42.3% and 35.62% on D4S405 and D4S3013 locus, respectively. Adjacent markers of D4S3013 displayed a low LOH frequency (4p15.2) and D4S405 (4p14) locus are detected. Candidate TSG, which is involved in carcinogenesis and progression of sporadic colorectal carcinoma on chromosome 4p, may be located between D4S3017 and D4S2933 (about 1.7 cm).

  15. Identification of new adventitious rooting mutants amongst suppressors of the Arabidopsis thaliana superroot2 mutation.

    Science.gov (United States)

    Pacurar, Daniel Ioan; Pacurar, Monica Lacramioara; Bussell, John Desmond; Schwambach, Joseli; Pop, Tiberia Ioana; Kowalczyk, Mariusz; Gutierrez, Laurent; Cavel, Emilie; Chaabouni, Salma; Ljung, Karin; Fett-Neto, Arthur Germano; Pamfil, Doru; Bellini, Catherine

    2014-04-01

    The plant hormone auxin plays a central role in adventitious rooting and is routinely used with many economically important, vegetatively propagated plant species to promote adventitious root initiation and development on cuttings. Nevertheless the molecular mechanisms through which it acts are only starting to emerge. The Arabidopsis superroot2-1 (sur2-1) mutant overproduces auxin and, as a consequence, develops excessive adventitious roots in the hypocotyl. In order to increase the knowledge of adventitious rooting and of auxin signalling pathways and crosstalk, this study performed a screen for suppressors of superroot2-1 phenotype. These suppressors provide a new resource for discovery of genetic players involved in auxin signalling pathways or at the crosstalk of auxin and other hormones or environmental signals. This study reports the identification and characterization of 26 sur2-1 suppressor mutants, several of which were identified as mutations in candidate genes involved in either auxin biosynthesis or signalling. In addition to confirming the role of auxin as a central regulator of adventitious rooting, superroot2 suppressors indicated possible crosstalk with ethylene signalling in this process.

  16. The tumor suppressor gene Trp53 protects the mouse lens against posterior subcapsular cataracts and the BMP receptor Acvr1 acts as a tumor suppressor in the lens

    Directory of Open Access Journals (Sweden)

    Luke A. Wiley

    2011-07-01

    We previously found that lenses lacking the Acvr1 gene, which encodes a bone morphogenetic protein (BMP receptor, had abnormal proliferation and cell death in epithelial and cortical fiber cells. We tested whether the tumor suppressor protein p53 (encoded by Trp53 affected this phenotype. Acvr1 conditional knockout (Acvr1CKO mouse fiber cells had increased numbers of nuclei that stained for p53 phosphorylated on serine 15, an indicator of p53 stabilization and activation. Deletion of Trp53 rescued the Acvr1CKO cell death phenotype in embryos and reduced Acvr1-dependent apoptosis in postnatal lenses. However, deletion of Trp53 alone increased the number of fiber cells that failed to withdraw from the cell cycle. Trp53CKO and Acvr1;Trp53DCKO (double conditional knockout, but not Acvr1CKO, lenses developed abnormal collections of cells at the posterior of the lens that resembled posterior subcapsular cataracts. Cells from human posterior subcapsular cataracts had morphological and molecular characteristics similar to the cells at the posterior of mouse lenses lacking Trp53. In Trp53CKO lenses, cells in the posterior plaques did not proliferate but, in Acvr1;Trp53DCKO lenses, many cells in the posterior plaques continued to proliferate, eventually forming vascularized tumor-like masses at the posterior of the lens. We conclude that p53 protects the lens against posterior subcapsular cataract formation by suppressing the proliferation of fiber cells and promoting the death of any fiber cells that enter the cell cycle. Acvr1 acts as a tumor suppressor in the lens. Enhancing p53 function in the lens could contribute to the prevention of steroid- and radiation-induced posterior subcapsular cataracts.

  17. A genomewide screen for suppressors of Alu-mediated rearrangements reveals a role for PIF1.

    Directory of Open Access Journals (Sweden)

    Karen M Chisholm

    Full Text Available Alu-mediated rearrangement of tumor suppressor genes occurs frequently during carcinogenesis. In breast cancer, this mechanism contributes to loss of the wild-type BRCA1 allele in inherited disease and to loss of heterozygosity in sporadic cancer. To identify genes required for suppression of Alu-mediated recombination we performed a genomewide screen of a collection of 4672 yeast gene deletion mutants using a direct repeat recombination assay. The primary screen and subsequent analysis identified 12 candidate genes including TSA, ELG1, and RRM3, which are known to play a significant role in maintaining genomic stability. Genetic analysis of the corresponding human homologs was performed in sporadic breast tumors and in inherited BRCA1-associated carcinomas. Sequencing of these genes in high risk breast cancer families revealed a potential role for the helicase PIF1 in cancer predisposition. PIF1 variant L319P was identified in three breast cancer families; importantly, this variant, which is predicted to be functionally damaging, was not identified in a large series of controls nor has it been reported in either dbSNP or the 1000 Genomes Project. In Schizosaccharomyces pombe, Pfh1 is required to maintain both mitochondrial and nuclear genomic integrity. Functional studies in yeast of human PIF1 L319P revealed that this variant cannot complement the essential functions of Pfh1 in either the nucleus or mitochondria. Our results provide a global view of nonessential genes involved in suppressing Alu-mediated recombination and implicate variation in PIF1 in breast cancer predisposition.

  18. MUC1-C activates polycomb repressive complexes and downregulates tumor suppressor genes in human cancer cells.

    Science.gov (United States)

    Rajabi, Hasan; Hiraki, Masayuki; Kufe, Donald

    2018-04-01

    The PRC2 and PRC1 complexes are aberrantly expressed in human cancers and have been linked to decreases in patient survival. MUC1-C is an oncoprotein that is also overexpressed in diverse human cancers and is associated with a poor prognosis. Recent studies have supported a previously unreported function for MUC1-C in activating PRC2 and PRC1 in cancer cells. In the regulation of PRC2, MUC1-C (i) drives transcription of the EZH2 gene, (ii) binds directly to EZH2, and (iii) enhances occupancy of EZH2 on target gene promoters with an increase in H3K27 trimethylation. Regarding PRC1, which is recruited to PRC2 sites in the hierarchical model, MUC1-C induces BMI1 transcription, forms a complex with BMI1, and promotes H2A ubiquitylation. MUC1-C thereby contributes to the integration of PRC2 and PRC1-mediated repression of tumor suppressor genes, such as CDH1, CDKN2A, PTEN and BRCA1. Like PRC2 and PRC1, MUC1-C is associated with the epithelial-mesenchymal transition (EMT) program, cancer stem cell (CSC) state, and acquisition of anticancer drug resistance. In concert with these observations, targeting MUC1-C downregulates EZH2 and BMI1, inhibits EMT and the CSC state, and reverses drug resistance. These findings emphasize the significance of MUC1-C as a therapeutic target for inhibiting aberrant PRC function and reprogramming the epigenome in human cancers.

  19. Tumor suppressor BLU inhibits proliferation of nasopharyngeal carcinoma cells by regulation of cell cycle, c-Jun N-terminal kinase and the cyclin D1 promoter

    International Nuclear Information System (INIS)

    Zhang, Xiangning; Liu, Hui; Li, Binbin; Huang, Peichun; Shao, Jianyong; He, Zhiwei

    2012-01-01

    Tumor suppressor genes function to regulate and block tumor cell proliferation. To explore the mechanisms underlying the tumor suppression of BLU/ZMYND10 gene on a frequently lost human chromosomal region, an adenoviral vector with BLU cDNA insert was constructed. BLU was re-expressed in nasopharyngeal carcinoma cells by transfection or viral infection. Clonogenic growth was assayed; cell cycle was analyzed by flow cytometry-based DNA content detection; c-Jun N-terminal kinase (JNK) and cyclin D1 promoter activities were measured by reporter gene assay, and phosphorylation was measured by immunoblotting. The data for each pair of groups were compared with Student t tests. BLU inhibits clonogenic growth of nasopharyngeal carcinoma cells, arrests cell cycle at G1 phase, downregulates JNK and cyclin D1 promoter activities, and inhibits phosphorylation of c-Jun. BLU inhibits growth of nasopharyngeal carcinoma cells by regulation of the JNK-cyclin D1 axis to exert tumor suppression

  20. Modulation of immune response by alloactivated suppressor T cells

    International Nuclear Information System (INIS)

    Bernstein, A.; Sopori, M.L.; Gose, J.E.; Sondel, P.M.

    1979-01-01

    These studies show that there may be several different kinds of suppressor cells, each activated by different pathways and able to suppress different parts of the immune response either specifically or nonspecifically. As such, the physiology of one type of suppressor cell need not necessarily apply to that of another type of suppressor. Thus we emphasize the trap that the suppressor cell option provides: that is, virtually any previously inexplicable in vitro and in vivo immune phenomenon can always be adequately accounted for by evoking a suppressor mechanism, either by suppressing the response or suppressing the suppressor

  1. NF2 tumor suppressor gene: a comprehensive and efficient detection of somatic mutations by denaturing HPLC and microarray-CGH.

    Science.gov (United States)

    Szijan, Irene; Rochefort, Daniel; Bruder, Carl; Surace, Ezequiel; Machiavelli, Gloria; Dalamon, Viviana; Cotignola, Javier; Ferreiro, Veronica; Campero, Alvaro; Basso, Armando; Dumanski, Jan P; Rouleau, Guy A

    2003-01-01

    The NF2 tumor suppressor gene, located in chromosome 22q12, is involved in the development of multiple tumors of the nervous system, either associated with neurofibromatosis 2 or sporadic ones, mainly schwannomas and meningiomas. In order to evaluate the role of the NF2 gene in sporadic central nervous system (CNS) tumors, we analyzed NF2 mutations in 26 specimens: 14 meningiomas, 4 schwannomas, 4 metastases, and 4 other histopathological types of neoplasms. Denaturing high performance liquid chromatography (denaturing HPLC) and comparative genomic hybridization on a DNA microarray (microarray- CGH) were used as scanning methods for small mutations and gross rearrangements respectively. Small mutations were identified in six out of seventeen meningiomas and schwannomas, one mutation was novel. Large deletions were detected in six meningiomas. All mutations were predicted to result in truncated protein or in the absence of a large protein domain. No NF2 mutations were found in other histopathological types of CNS tumors. These results provide additional evidence that mutations in the NF2 gene play an important role in the development of sporadic meningiomas and schwannomas. Denaturing HPLC analysis of small mutations and microarray-CGH of large deletions are complementary, fast, and efficient methods for the detection of mutations in tumor tissues.

  2. KLF10, transforming growth factor-{beta}-inducible early gene 1, acts as a tumor suppressor

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki-Duk [Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Laboratory of Protein Engineering and Comparative Immunology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Kim, Duk-Jung [The Institute of Hankook Life Science, 7-9 Myungryun-dong, Jongno-gu, Seoul 110-521 (Korea, Republic of); Lee, Jong Eun [Department of Anatomy, College of Medicine, Yonsei University, Seoul 120-752 (Korea, Republic of); Yun, Cheol-Heui [Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Laboratory of Protein Engineering and Comparative Immunology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Lee, Woon Kyu, E-mail: wklee@inha.ac.kr [Laboratory of Developmental Genetics, School of Medicine, Inha University, Incheon 400-712 (Korea, Republic of); Brain Korea 21 Center for Advanced Medical Education, School of Medicine, Inha University, Incheon 400-712 (Korea, Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer KLF10{sup -/-} mice exhibited accelerated papilloma development after DMBA/TPA treatment. Black-Right-Pointing-Pointer KLF10{sup -/-} keratinocytes showed increased proliferation and apoptosis. Black-Right-Pointing-Pointer KLF10{sup -/-} MEFs yielded more colonies than wild-type one with H-Ras transfection. Black-Right-Pointing-Pointer KLF10 dose-dependently activated p21{sup WAF1/CIP1} transcription. Black-Right-Pointing-Pointer KLF10 is a tumor suppressor and that it targets p21{sup WAF1/CIP1} transcription. -- Abstract: Krueppel-like factor 10 (KLF10) has been suggested to be a putative tumor suppressor. In the present study, we generated KLF10 deficient mice to explore this hypothesis in vivo. KLF10 deficient mice exhibited increased predisposition to skin tumorigenesis and markedly accelerated papilloma development after DMBA/TPA treatment. On the other hand, KLF10 deficient keratinocytes showed increased proliferation and apoptosis. In colony formation assays after oncogenic H-Ras transfection, KLF10 deficient mouse embryonic fibroblasts (MEFs) yielded more colonies than wild-type MEFs. Furthermore, KLF10 dose-dependently activated p21{sup WAF1/CIP1} transcription, which was independent of p53 and Sp1 binding sites in p21{sup WAF1/CIP1} promoter. This study demonstrates that KLF10 is a tumor suppressor and that it targets p21{sup WAF1/CIP1} transcription.

  3. Identification of a third protein 4.1 tumor suppressor, protein 4.1R, in meningioma pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Robb, Victoria A.; Li, Wen; Gascard, Philippe; Perry, Arie; Mohandas, Narla; Gutmann, David H.

    2003-06-11

    Meningiomas are common tumors of the central nervous system, however, the mechanisms under lying their pathogenesis are largely undefined. Two members of the Protein 4.1 super family, the neuro fibromatosis 2 (NF2) gene product (merlin/schwannomin) and Protein 4.1B have been implicated as meningioma tumor suppressors. In this report, we demonstrate that another Protein 4.1 family member, Protein 4.1R, also functions as a meningioma tumor suppressor. Based on the assignment of the Protein 4.1R gene to chromosome 1p32-36, a common region of deletion observed in meningiomas, we analyzed Protein 4.1R expression in meningioma cell lines and surgical tumor specimens. We observed loss of Protein 4.1R protein expression in two meningioma cell lines (IOMM-Lee, CH157-MN) by Western blotting as well as in 6 of 15 sporadic meningioma as by immuno histo chemistry (IHC). Analysis of a subset of these sporadic meningiomas by fluorescent in situ hybridization (FISH) with a Protein 4.1R specific probe demonstrated 100 percent concordance with the IHC results. In support of a meningioma tumor suppressor function, over expression of Protein 4.1R resulted in suppression of IOMM-Lee and CH157MN cell proliferation. Similar to the Protein 4.1B and merlin meningioma tumor suppressors, Protein 4.1R localization in the membrane fraction increased significantly under conditions of growth arrest in vitro. Lastly, Protein 4.1R interacted with some known merlin/Protein 4.1B interactors such as CD44 and bII-spectrin, but did not associate with the Protein 4.1B interactors 14-3-3 and PRMT3 or the merlin binding proteins SCHIP-1 and HRS. Collectively, these results suggest that Protein 4.1R functions as an important tumor suppressor important in the molecular pathogenesis of meningioma.

  4. Loss of heterozygosity for defined regions on chromosomes 3, 11 and 17 in carcinomas of the uterine cervix

    NARCIS (Netherlands)

    Kersemaekers, A. M.; Hermans, J.; Fleuren, G. J.; van de Vijver, M. J.

    1998-01-01

    Loss of heterozygosity (LOH) frequently occurs in squamous cell carcinomas of the uterine cervix and indicates the probable sites of tumour-suppressor genes that play a role in the development of this tumour. To define the localization of these tumour-suppressor genes, we studied loss of

  5. Inactivation of tumor suppressor genes and cancer therapy: An evolutionary game theory approach.

    Science.gov (United States)

    Khadem, Heydar; Kebriaei, Hamed; Veisi, Zahra

    2017-06-01

    Inactivation of alleles in tumor suppressor genes (TSG) is one of the important issues resulting in evolution of cancerous cells. In this paper, the evolution of healthy, one and two missed allele cells is modeled using the concept of evolutionary game theory and replicator dynamics. The proposed model also takes into account the interaction rates of the cells as designing parameters of the system. Different combinations of the equilibrium points of the parameterized nonlinear system is studied and categorized into some cases. In each case, the interaction rates' values are suggested in a way that the equilibrium points of the replicator dynamics are located on an appropriate region of the state space. Based on the suggested interaction rates, it is proved that the system doesn't have any undesirable interior equilibrium point as well. Therefore, the system will converge to the desirable region, where there is a scanty level of cancerous cells. In addition, the proposed conditions for interaction rates guarantee that, when a trajectory of the system reaches the boundaries, then it will stay there forever which is a desirable property since the equilibrium points have been already located on the boundaries, appropriately. The simulation results show the effectiveness of the suggestions in the elimination of the cancerous cells in different scenarios. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. The Role of Tumor Metastases Suppressor Gene, Drg-1, in Breast Cancer

    Science.gov (United States)

    2008-03-01

    evidence to validate 14 our data of breast cancer. However, these prostate cells and reagents were existing materials in our lab or purchased by using...J. Lab . Clin. Med. 133, 265–273. Sloane, B.F., Honn, K.V., 1984. Cysteine proteinases and metastasis. Cancer Metastasis Rev. 3, 249–263. Sridhar, S.C... Beest , P. Moerer, K. van der Horn, R. Goldschmeding, T. Logtenberg and H. Clevers: Synergy between tumor suppressor APC and the beta- catenin-Tcf4

  7. Loss of heterozygosity of CDKN2A (p16INK4a) and RB1 tumor suppressor genes in testicular germ cell tumors

    International Nuclear Information System (INIS)

    Vladusic, Tomislav; Hrascan, Reno; Pecina-Slaus, Nives; Vrhovac, Ivana; Gamulin, Marija; Franekic, Jasna; Kruslin, Bozo

    2010-01-01

    Testicular germ cell tumors (TGCTs) are the most frequent malignances in young adult men. The two main histological forms, seminomas and nonseminomas, differ biologically and clinically. pRB protein and its immediate upstream regulator p16INK4a are involved in the RB pathway which is deregulated in most TGCTs. The objective of this study was to evaluate the occurrence of loss of heterozygosity (LOH) of the CDKN2A (p16INK4a) and RB1 tumor suppressor genes in TGCTs. Forty TGCTs (18 seminomas and 22 nonseminomas) were analyzed by polymerase chain reaction using the restriction fragment length polymorphism or the nucleotide repeat polymorphism method. LOH of the CDKN2A was found in two (6%) out of 34 (85%) informative cases of our total TGCT sample. The observed changes were assigned to two (11%) nonseminomas out of 18 (82%) informative samples. Furthermore, LOH of the RB1 was detected in two (6%) out of 34 (85%) informative cases of our total TGCT sample. Once again, the observed changes were assigned to two (10.5%) nonseminomas out of 19 (86%) informative samples. Both LOHs of the CDKN2A were found in nonseminomas with a yolk sac tumor component, and both LOHs of the RB1 were found in nonseminomas with an embryonal carcinoma component. The higher incidence of observed LOH in nonseminomas may provide a clue to their invasive behavior

  8. An unusual characteristic "flower-like" pattern: flash suppressor burns.

    Science.gov (United States)

    Gurcan, Altun

    2012-04-01

    The case on contact shots from firearms with a flash suppressor is rare. When a rifle fitted with a flash suppressor is fired, the emerging soot-laden gas in the barrel escapes from the slits of the flash suppressor. If the shot is contact or near contact, the flash suppressor will produce a characteristic "flower-like" pattern of seared, blackened zones around the entrance. This paper presents the injury pattern of the flash suppressor in a 29-year-old man who committed suicide with a G3 automatic infantry rifle.

  9. Epigenetic silencing of MAL, a putative tumor suppressor gene, can contribute to human epithelium cell carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang Jun

    2010-11-01

    suppressor gene, can contribute to human epithelial cell carcinoma and may be served as a biomarker in HNSCC.

  10. Abnormal P-53 suppressor gene expression predicts for a poorer outcome in patients with locally advanced adenocarcinoma of the prostate treated by external beam radiation therapy with or without pre-radiation androgen ablation: results based on RTOG study 86-10

    International Nuclear Information System (INIS)

    Lawton, Colleen A.; Grignon, David; Caplan, Richard; Sarkar, Fazlul; Forman, Jeffrey; Mesic, John; Fu, Karen K.; Abrams, Ross

    1995-01-01

    Purpose/Objective: The purpose of this study is to establish the effect of the abnormal expression of the P-53 suppressor gene on the results of locally advanced adenocarcinoma of the prostate treated with radiation therapy with or without pre-radiation therapy androgen ablation. Materials and Methods: Patients evaluated were part of a RTOG phase III multi-institutional trial. This trial assessed the value of pre-radiation therapy androgen ablation on patients with locally advanced disease (bulky stage B and stage C). Of the 471 patients registered, pre-treatment pathological material was available for 129 patients. P-53 status was determined immunohistochemically utilizing a commercially available antibody (D07). Clinical endpoints evaluated were overall survival and development of metastases. Results: Twenty-three of the 129 patients had abnormal expression of the P-53 suppressor gene. Presence of this abnormal expression significantly correlated with lower overall survival (p=0.03) and the development of distant metastases (p=0.03). Abnormal expression of the P-53 gene was an independent prognostic indicator when evaluated against clinical stage and Gleason score. Conclusion: This data from patients entered on a phase III multi-institutional, randomized clinical trial shows that abnormal P-53 suppressor gene expression as determined immunohistochemically is an independent predictor of poorer survival and the development of distant metastases in patients with locally advanced adenocarcinoma of the prostate treated with radiation therapy with or without pre-radiation therapy androgen ablation

  11. The genomic structure of the DMBT1 gene

    DEFF Research Database (Denmark)

    Mollenhauer, J; Holmskov, U; Wiemann, S

    1999-01-01

    Increasing evidence has accumulated for an involvement of the inactivation of tumour suppressor genes at chromosome 10q in the carcinogenesis of brain tumours, melanomas, and carcinomas of the lung, the prostate, the pancreas, and the endometrium. The gene DMBT1 (Deleted in Malignant Brain Tumours...... 1) is located at chromosome 10q25.3-q26.1, within one of the putative intervals for tumour suppressor genes. DMBT1 is a member of the scavenger-receptor cysteine-rich (SRCR) superfamily and displays homozygous deletions or lack of expression in glioblastoma multiforme, medulloblastoma......, and in gastrointestinal and lung cancers. Based on these properties, DMBT1 has been proposed to be a candidate tumour suppressor gene. We have determined the genomic sequence of DMBT1 to allow analyses of mutations. The gene has at least 54 exons that span a genomic region of about 80 kb. We have identified a putative...

  12. Inference of cancer-specific gene regulatory networks using soft computing rules.

    Science.gov (United States)

    Wang, Xiaosheng; Gotoh, Osamu

    2010-03-24

    Perturbations of gene regulatory networks are essentially responsible for oncogenesis. Therefore, inferring the gene regulatory networks is a key step to overcoming cancer. In this work, we propose a method for inferring directed gene regulatory networks based on soft computing rules, which can identify important cause-effect regulatory relations of gene expression. First, we identify important genes associated with a specific cancer (colon cancer) using a supervised learning approach. Next, we reconstruct the gene regulatory networks by inferring the regulatory relations among the identified genes, and their regulated relations by other genes within the genome. We obtain two meaningful findings. One is that upregulated genes are regulated by more genes than downregulated ones, while downregulated genes regulate more genes than upregulated ones. The other one is that tumor suppressors suppress tumor activators and activate other tumor suppressors strongly, while tumor activators activate other tumor activators and suppress tumor suppressors weakly, indicating the robustness of biological systems. These findings provide valuable insights into the pathogenesis of cancer.

  13. Myxovirus resistance, osteopontin and suppressor of cytokine signaling 3 polymorphisms predict hepatitis C virus therapy response in an admixed patient population: comparison with IL28B.

    Science.gov (United States)

    Angelo, Ana Luiza Dias; Cavalcante, Lourianne Nascimento; Abe-Sandes, Kiyoko; Machado, Taísa Bonfim; Lemaire, Denise Carneiro; Malta, Fernanda; Pinho, João Renato; Lyra, Luiz Guilherme Costa; Lyra, Andre Castro

    2013-10-01

    Suppressor of cytokine signaling 3, myxovirus resistance protein and osteopontin gene polymorphisms may influence the therapeutic response in patients with chronic hepatitis C, and an association with IL28 might increase the power to predict sustained virologic response. Our aims were to evaluate the association between myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 gene polymorphisms in combination with IL28B and to assess the therapy response in hepatitis C patients treated with pegylated-interferon plus ribavirin. Myxovirus resistance protein, osteopontin, suppressor of cytokine signaling 3 and IL28B polymorphisms were analyzed by PCR-restriction fragment length polymorphism, direct sequencing and real-time PCR. Ancestry was determined using genetic markers. We analyzed 181 individuals, including 52 who were sustained virologic responders. The protective genotype frequencies among the sustained virologic response group were as follows: the G/G suppressor of cytokine signaling 3 (rs4969170) (62.2%); T/T osteopontin (rs2853744) (60%); T/T osteopontin (rs11730582) (64.3%); and the G/T myxovirus resistance protein (rs2071430) genotype (54%). The patients who had ≥3 of the protective genotypes from the myxovirus resistance protein, the suppressor of cytokine signaling 3 and osteopontin had a greater than 90% probability of achieving a sustained response (pC/C IL28B genotype was present in 58.8% of the subjects in this group. The sustained virological response rates increased to 85.7% and 91.7% by analyzing C/C IL28B with the T/T osteopontin genotype at rs11730582 and the G/G suppressor of cytokine signaling 3 genotype, respectively. Genetic ancestry analysis revealed an admixed population. Hepatitis C genotype 1 patients who were responders to interferon-based therapy had a high frequency of multiple protective polymorphisms in the myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 genes. The combined

  14. Heterozygous Germline Mutations in the CBL Tumor-Suppressor Gene Cause a Noonan Syndrome-like Phenotype

    Science.gov (United States)

    Martinelli, Simone; De Luca, Alessandro; Stellacci, Emilia; Rossi, Cesare; Checquolo, Saula; Lepri, Francesca; Caputo, Viviana; Silvano, Marianna; Buscherini, Francesco; Consoli, Federica; Ferrara, Grazia; Digilio, Maria C.; Cavaliere, Maria L.; van Hagen, Johanna M.; Zampino, Giuseppe; van der Burgt, Ineke; Ferrero, Giovanni B.; Mazzanti, Laura; Screpanti, Isabella; Yntema, Helger G.; Nillesen, Willy M.; Savarirayan, Ravi; Zenker, Martin; Dallapiccola, Bruno; Gelb, Bruce D.; Tartaglia, Marco

    2010-01-01

    RAS signaling plays a key role in controlling appropriate cell responses to extracellular stimuli and participates in early and late developmental processes. Although enhanced flow through this pathway has been established as a major contributor to oncogenesis, recent discoveries have revealed that aberrant RAS activation causes a group of clinically related developmental disorders characterized by facial dysmorphism, a wide spectrum of cardiac disease, reduced growth, variable cognitive deficits, ectodermal and musculoskeletal anomalies, and increased risk for certain malignancies. Here, we report that heterozygous germline mutations in CBL, a tumor-suppressor gene that is mutated in myeloid malignancies and encodes a multivalent adaptor protein with E3 ubiquitin ligase activity, can underlie a phenotype with clinical features fitting or partially overlapping Noonan syndrome (NS), the most common condition of this disease family. Independent CBL mutations were identified in two sporadic cases and two families from among 365 unrelated subjects who had NS or suggestive features and were negative for mutations in previously identified disease genes. Phenotypic heterogeneity and variable expressivity were documented. Mutations were missense changes altering evolutionarily conserved residues located in the RING finger domain or the linker connecting this domain to the N-terminal tyrosine kinase binding domain, a known mutational hot spot in myeloid malignancies. Mutations were shown to affect CBL-mediated receptor ubiquitylation and dysregulate signal flow through RAS. These findings document that germline mutations in CBL alter development to cause a clinically variable condition that resembles NS and that possibly predisposes to malignancies. PMID:20619386

  15. Zebrafish mutants in the von Hippel-Lindau tumor suppressor display a hypoxic response and recapitulate key aspects of Chuvash polycythemia

    NARCIS (Netherlands)

    van Rooijen, E.; Voest, E.E.; Logister, I.; Korving, J.; Schwerte, T.; Schulte-Merker, S.; Giles, R.H.; van Eeden, F.J.

    2009-01-01

    We have generated 2 zebrafish lines carrying inactivating germline mutations in the von Hippel-Lindau (VHL) tumor suppressor gene ortholog vhl. Mutant embryos display a general systemic hypoxic response, including the up-regulation of hypoxia-induced genes by 1 day after fertilization and a severe

  16. miR-199a-3p displays tumor suppressor functions in papillary thyroid carcinoma.

    Science.gov (United States)

    Minna, Emanuela; Romeo, Paola; De Cecco, Loris; Dugo, Matteo; Cassinelli, Giuliana; Pilotti, Silvana; Degl'Innocenti, Debora; Lanzi, Cinzia; Casalini, Patrizia; Pierotti, Marco A; Greco, Angela; Borrello, Maria Grazia

    2014-05-15

    Thyroid cancer incidence is rapidly increasing. Papillary Thyroid Carcinoma (PTC), the most frequent hystotype, usually displays good prognosis, but no effective therapeutic options are available for the fraction of progressive PTC patients. BRAF and RET/PTC are the most frequent driving genetic lesions identified in PTC. We developed two complementary in vitro models based on RET/PTC1 oncogene, starting from the hypothesis that miRNAs modulated by a driving PTC-oncogene are likely to have a role in thyroid neoplastic processes. Through this strategy, we identified a panel of deregulated miRNAs. Among these we focused on miR-199a-3p and showed its under-expression in PTC specimens and cell lines. We demonstrated that miR-199a-3p restoration in PTC cells reduces MET and mTOR protein levels, impairs migration and proliferation and, more interesting, induces lethality through an unusual form of cell death similar to methuosis, caused by macropinocytosis dysregulation. Silencing MET or mTOR, both involved in survival pathways, does not recapitulate miR-199a-3p-induced cell lethality, thus suggesting that the cooperative regulation of multiple gene targets is necessary. Integrated analysis of miR-199a-3p targets unveils interesting networks including HGF and macropinocytosis pathways. Overall our results indicate miR-199a-3p as a tumor suppressor miRNA in PTC.

  17. The essential Escherichia coli msgB gene, a multicopy suppressor of a temperature-sensitive allele of the heat shock gene grpE, is identical to dapE.

    Science.gov (United States)

    Wu, B; Georgopoulos, C; Ang, D

    1992-08-01

    The grpE gene product is one of three Escherichia coli heat shock proteins (DnaK, DnaJ, and GrpE) that are essential for both bacteriophage lambda DNA replication and bacterial growth at all temperatures. In an effort to determine the role of GrpE and to identify other factors that it may interact with, we isolated multicopy suppressors of the grpE280 point mutation, as judged by their ability to reverse the temperature-sensitive phenotype of grpE280. Here we report the characterization of one of them, designated msgB. The msgB gene maps at approximately 53 min on the E. coli chromosome. The minimal gene possesses an open reading frame that encodes a protein with a predicted size of 41,269 M(r). This open reading frame was confirmed the correct one by direct amino-terminal sequence analysis of the overproduced msgB gene product. Genetic experiments demonstrated that msgB is essential for E. coli growth in the temperature range of 22 to 37 degrees C. Through a sequence homology search, MsgB was shown to be identical to N-succinyl-L-diaminopimelic acid desuccinylase (the dapE gene product), which participates in the diaminopimelic acid-lysine pathway involved in cell wall biosynthesis. Consistent with this finding, the msgB null allele mutant is viable only when the growth medium is supplemented with diaminopimelic acid. These results suggest that GrpE may have a previously unsuspected function(s) in cell wall biosynthesis in E. coli.

  18. miR-7 and miR-218 epigenetically control tumor suppressor genes RASSF1A and Claudin-6 by targeting HoxB3 in breast cancer

    International Nuclear Information System (INIS)

    Li, Qiaoyan; Zhu, Fufan; Chen, Puxiang

    2012-01-01

    Highlights: ► Both miR-7 and miR-218 down-regulates HoxB3 expression by targeting the 3′-UTR of HoxB3 mRNA. ► A reverse correlation between the levels of endogenous miR-7, miR218 and HoxB3 expression. ► Epigenetic changes involve in the reactivation of HoxB3. ► Both miRNAs inhibits the cell cycle and clone formation of breast cancer cells. -- Abstract: Many microRNAs have been implicated as key regulators of cellular growth and differentiation and have been found to dysregulate proliferation in human tumors, including breast cancer. Cancer-linked microRNAs also alter the epigenetic landscape by way of DNA methylation and post-translational modifications of histones. Aberrations in Hox gene expression are important for oncogene or tumor suppressor during abnormal development and malignancy. Although recent studies suggest that HoxB3 is critical in breast cancer, the putative role(s) of microRNAs impinging on HoxB3 is not yet fully understood. In this study, we found that the expression levels of miR-7 and miR-218 were strongly and reversely associated with HoxB3 expression. Stable overexpression of miR-7 and miR-218 was accompanied by reactivation of tumor suppressor genes including RASSF1A and Claudin-6 by means of epigenetic switches in DNA methylation and histone modification, giving rise to inhibition of the cell cycle and clone formation of breast cancer cells. The current study provides a novel link between overexpression of collinear Hox genes and multiple microRNAs in human breast malignancy.

  19. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    International Nuclear Information System (INIS)

    Kurayoshi, Kenta; Ozono, Eiko; Iwanaga, Ritsuko; Bradford, Andrew P.; Komori, Hideyuki; Ohtani, Kiyoshi

    2014-01-01

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  20. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    Energy Technology Data Exchange (ETDEWEB)

    Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-07-18

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  1. Mapping the glaucousness suppressor Iw1 from wild emmer wheat “PI 481521”

    Institute of Scientific and Technical Information of China (English)

    Zongchang; Xu; Cuiling; Yuan; Jirui; Wang; Daolin; Fu; Jiajie; Wu

    2015-01-01

    Many species of Triticeae display a glaucous phenotype. In wheat, glaucousness/waxiness on spikes, leaves and shoots is controlled by wax production genes(W loci) and epistatic inhibitors(Iw loci). In this study, a suppressor of glaucousness from wild emmer wheat(Triticum turgidum ssp. dicoccoides) accession "PI 481521" was investigated in a pair of durum(T. turgidum ssp. durum cv. "Langdon", LDN)—wild emmer wheat chromosome substitution lines, LDN and "LDNDIC521-2B". Genetic analysis revealed that the non-glaucous phenotype of LDNDIC521-2Bwas controlled by the dominant glaucous suppressor Iw1 on the short arm of chromosome 2B. In total, 371 2B-specific marker differences were identified between LDN and LDNDIC521-2B. The location of the Iw1 gene was mapped using an F2 population that stemmed from LDN and LDNDIC521-2B, generating a partial linkage map that included 19 simple sequence repeats(SSR) and ten gene-based markers. On the current map, the Iw1 gene was located within the Xgwm614–BE498111 interval, and cosegregated with BQ788707,CD893659, CD927782, CD938589, and Xbarc35. Mapping of Iw1 in LDNDIC521-2B, a publically accessible and widely distributed line, will provide valuable information for marker-assisted selection of the agronomically important trait of glaucousness.

  2. Protein tyrosine phosphatase receptor delta acts as a neuroblastoma tumor suppressor by destabilizing the aurora kinase a oncogene

    LENUS (Irish Health Repository)

    Meehan, Maria

    2012-02-05

    Abstract Background Protein tyrosine phosphatase receptor delta (PTPRD) is a member of a large family of protein tyrosine phosphatases which negatively regulate tyrosine phosphorylation. Neuroblastoma is a major childhood cancer arising from precursor cells of the sympathetic nervous system which is known to acquire deletions and alterations in the expression patterns of PTPRD, indicating a potential tumor suppressor function for this gene. The molecular mechanism, however, by which PTPRD renders a tumor suppressor effect in neuroblastoma is unknown. Results As a molecular mechanism, we demonstrate that PTPRD interacts with aurora kinase A (AURKA), an oncogenic protein that is over-expressed in multiple forms of cancer, including neuroblastoma. Ectopic up-regulation of PTPRD in neuroblastoma dephosphorylates tyrosine residues in AURKA resulting in a destabilization of this protein culminating in interfering with one of AURKA\\'s primary functions in neuroblastoma, the stabilization of MYCN protein, the gene of which is amplified in approximately 25 to 30% of high risk neuroblastoma. Conclusions PTPRD has a tumor suppressor function in neuroblastoma through AURKA dephosphorylation and destabilization and a downstream destabilization of MYCN protein, representing a novel mechanism for the function of PTPRD in neuroblastoma.

  3. miRNA Gene Promoters Are Frequent Targets of Aberrant DNA Methylation in Human Breast Cancer

    Czech Academy of Sciences Publication Activity Database

    Vrba, Lukáš; Munoz-Rodriguez, J.L.; Stampfer, M.R.; Futscher, B. W.

    2013-01-01

    Roč. 8, č. 1 (2013), e54398 E-ISSN 1932-6203 Institutional support: RVO:60077344 Keywords : Tumor-Suppressor * feedback loop * microRNAs Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.534, year: 2013

  4. Induction of suppressor cells in vitro by Candida albicans.

    Science.gov (United States)

    Cuff, C F; Rogers, C M; Lamb, B J; Rogers, T J

    1986-06-01

    Normal splenocytes cultured with Formalin-killed Candida albicans were shown to acquire significant suppressor cell activity in a period of 3 days. These cells were found to suppress both the phytohemagglutinin-induced mitogen response as well as the anti-sheep erythrocyte antibody response. Experiments were carried out to determine the nature of the suppressor cell population. Results showed that these cells were not susceptible to treatment with anti-Thy 1 antibody and complement. Panning experiments showed that the suppressor cells were not plastic-adherent or Mac-1 antigen-positive. The suppressor cells were, however, adherent to anti-mouse immunoglobulin (F(ab')2-fragment)-coated dishes. Additional experiments showed that the suppressor cell activity was susceptible to treatment with monoclonal anti-Lyb 2.1 antibody and complement. These results suggest that the suppressor cell induced in vitro by Candida is a member of the B-lymphocyte lineage.

  5. The SRS2 suppressor of rad6 mutations of Saccharomyces cerevisiae acts by channeling DNA lesions into the RAD52 DNA repair pathway

    International Nuclear Information System (INIS)

    Schiestl, R.H.; Prakash, S.; Prakash, L.

    1990-01-01

    rad6 mutants of Saccharomyces cerevisiae are defective in the repair of damaged DNA, DNA damage induced mutagenesis, and sporulation. In order to identify genes that can substitute for RAD6 function, the authors have isolated genomic suppressors of the UV sensitivity of rad6 deletion (rad6Δ) mutations and show that they also suppress the γ-ray sensitivity but not the UV mutagenesis or sporulation defects of rad6. The suppressors show semidominance for suppression of UV sensitivity and dominance for suppression of γ-ray sensitivity. The six suppressor mutations they isolated are all alleles of the same locus and are also allelic to a previously described suppressor of the rad6-1 nonsense mutation, SRS2. They show that suppression of rad6Δ is dependent on the RAD52 recombinational repair pathway since suppression is not observed in the rad6Δ SRS2 strain containing an additional mutation in either the RAD51, RAD52, RAD54, RAD55 or RAD57 genes. Possible mechanisms by which SRS2 may channel unrepaired DNA lesions into the RAD52 DNA repair pathway are discussed

  6. Epigenetic identification of ZNF545 as a functional tumor suppressor in multiple myeloma via activation of p53 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yu [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Zhan, Qian [The Center for Clinical Molecular Medical Detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Xu, Hongying [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Li, Lili; Li, Chen [Cancer Epigenetics Laboratory, Department of Clinical Oncology, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong and CUHK Shenzhen Research Institute (Hong Kong); Xiao, Qian; Xiang, Shili; Hui, Tianli [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Xiang, Tingxiu, E-mail: larissaxiang@163.com [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Ren, Guosheng, E-mail: rengs726@126.com [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China)

    2016-06-10

    The KRAB–zinc-finger protein ZNF545 was recently identified as a potential suppressor gene in several tumors. However, the regulatory mechanisms of ZNF545 in tumorigenesis remain unclear. In this study, we investigated the expression and roles of ZNF545 in multiple myeloma (MM). ZNF545 was frequently downregulated in MM tissues compared with non-tumor bone marrow tissues. ZNF545 expression was silenced by promoter methylation in MM cell lines, and could be restored by demethylation treatment. ZNF545 methylation was detected in 28.3% of MM tissues, compared with 4.3% of normal bone marrow tissues. ZNF545 transcriptionally activated the p53 signaling pathway but had no effect on Akt in MM, whereas ectopic expression of ZNF545 in silenced cells suppressed their proliferation and induced apoptosis. We therefore identified ZNF545 as a novel tumor suppressor inhibiting tumor growth through activation of the p53 pathway in MM. Moreover, tumor-specific methylation of ZNF545 may represent an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. -- Highlights: •Downregulated ZNF545 in MM tissues and cell lines and ectopic expression of ZNF545 suppresses tumor growth. •Tumor-specific methylation of ZNF545 represents an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. •ZNF545 exerts its tumor suppressive effects via transcriptional activating p53 pathway.

  7. Epigenetic identification of ZNF545 as a functional tumor suppressor in multiple myeloma via activation of p53 signaling pathway

    International Nuclear Information System (INIS)

    Fan, Yu; Zhan, Qian; Xu, Hongying; Li, Lili; Li, Chen; Xiao, Qian; Xiang, Shili; Hui, Tianli; Xiang, Tingxiu; Ren, Guosheng

    2016-01-01

    The KRAB–zinc-finger protein ZNF545 was recently identified as a potential suppressor gene in several tumors. However, the regulatory mechanisms of ZNF545 in tumorigenesis remain unclear. In this study, we investigated the expression and roles of ZNF545 in multiple myeloma (MM). ZNF545 was frequently downregulated in MM tissues compared with non-tumor bone marrow tissues. ZNF545 expression was silenced by promoter methylation in MM cell lines, and could be restored by demethylation treatment. ZNF545 methylation was detected in 28.3% of MM tissues, compared with 4.3% of normal bone marrow tissues. ZNF545 transcriptionally activated the p53 signaling pathway but had no effect on Akt in MM, whereas ectopic expression of ZNF545 in silenced cells suppressed their proliferation and induced apoptosis. We therefore identified ZNF545 as a novel tumor suppressor inhibiting tumor growth through activation of the p53 pathway in MM. Moreover, tumor-specific methylation of ZNF545 may represent an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. -- Highlights: •Downregulated ZNF545 in MM tissues and cell lines and ectopic expression of ZNF545 suppresses tumor growth. •Tumor-specific methylation of ZNF545 represents an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. •ZNF545 exerts its tumor suppressive effects via transcriptional activating p53 pathway.

  8. Inference of Cancer-specific Gene Regulatory Networks Using Soft Computing Rules

    Directory of Open Access Journals (Sweden)

    Xiaosheng Wang

    2010-03-01

    Full Text Available Perturbations of gene regulatory networks are essentially responsible for oncogenesis. Therefore, inferring the gene regulatory networks is a key step to overcoming cancer. In this work, we propose a method for inferring directed gene regulatory networks based on soft computing rules, which can identify important cause-effect regulatory relations of gene expression. First, we identify important genes associated with a specific cancer (colon cancer using a supervised learning approach. Next, we reconstruct the gene regulatory networks by inferring the regulatory relations among the identified genes, and their regulated relations by other genes within the genome. We obtain two meaningful findings. One is that upregulated genes are regulated by more genes than downregulated ones, while downregulated genes regulate more genes than upregulated ones. The other one is that tumor suppressors suppress tumor activators and activate other tumor suppressors strongly, while tumor activators activate other tumor activators and suppress tumor suppressors weakly, indicating the robustness of biological systems. These findings provide valuable insights into the pathogenesis of cancer.

  9. HC-Pro silencing suppressor significantly alters the gene expression profile in tobacco leaves and flowers

    Directory of Open Access Journals (Sweden)

    Lehto Kirsi

    2011-04-01

    Full Text Available Abstract Background RNA silencing is used in plants as a major defence mechanism against invasive nucleic acids, such as viruses. Accordingly, plant viruses have evolved to produce counter defensive RNA-silencing suppressors (RSSs. These factors interfere in various ways with the RNA silencing machinery in cells, and thereby disturb the microRNA (miRNA mediated endogene regulation and induce developmental and morphological changes in plants. In this study we have explored these effects using previously characterized transgenic tobacco plants which constitutively express (under CaMV 35S promoter the helper component-proteinase (HC-Pro derived from a potyviral genome. The transcript levels of leaves and flowers of these plants were analysed using microarray techniques (Tobacco 4 × 44 k, Agilent. Results Over expression of HC-Pro RSS induced clear phenotypic changes both in growth rate and in leaf and flower morphology of the tobacco plants. The expression of 748 and 332 genes was significantly changed in the leaves and flowers, respectively, in the HC-Pro expressing transgenic plants. Interestingly, these transcriptome alterations in the HC-Pro expressing tobacco plants were similar as those previously detected in plants infected with ssRNA-viruses. Particularly, many defense-related and hormone-responsive genes (e.g. ethylene responsive transcription factor 1, ERF1 were differentially regulated in these plants. Also the expression of several stress-related genes, and genes related to cell wall modifications, protein processing, transcriptional regulation and photosynthesis were strongly altered. Moreover, genes regulating circadian cycle and flowering time were significantly altered, which may have induced a late flowering phenotype in HC-Pro expressing plants. The results also suggest that photosynthetic oxygen evolution, sugar metabolism and energy levels were significantly changed in these transgenic plants. Transcript levels of S

  10. Classification of suppressor additives based on synergistic and antagonistic ensemble effects

    Energy Technology Data Exchange (ETDEWEB)

    Broekmann, P., E-mail: peter.broekmann@iac.unibe.ch [BASF SE, Global Business Unit Electronic Materials, 67056 Ludwigshafen (Germany); Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Fluegel, A.; Emnet, C.; Arnold, M.; Roeger-Goepfert, C.; Wagner, A. [BASF SE, Global Business Unit Electronic Materials, 67056 Ludwigshafen (Germany); Hai, N.T.M. [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Mayer, D. [BASF SE, Global Business Unit Electronic Materials, 67056 Ludwigshafen (Germany)

    2011-05-01

    Highlights: > Three fundamental types of suppressor additives for copper electroplating could be identified by means of potential transient measurements. > These suppressor additives differ in their synergistic and antagonistic interplay with anions that are chemisorbed on the metallic copper surface during electrodeposition. > In addition these suppressor chemistries reveal different barrier properties with respect to cupric ions and plating additives (Cl, SPS). - Abstract: Three fundamental types of suppressor additives for copper electroplating could be identified by means of potential transient measurements. These suppressor additives differ in their synergistic and antagonistic interplay with anions that are chemisorbed on the metallic copper surface during electrodeposition. In addition these suppressor chemistries reveal different barrier properties with respect to cupric ions and plating additives (Cl, SPS). While the type-I suppressor selectively forms efficient barriers for copper inter-diffusion on chloride-terminated electrode surfaces we identified a type-II suppressor that interacts non-selectively with any kind of anions chemisorbed on copper (chloride, sulfate, sulfonate). Type-I suppressors are vital for the superconformal copper growth mode in Damascene processing and show an antagonistic interaction with SPS (Bis-Sodium-Sulfopropyl-Disulfide) which involves the deactivation of this suppressor chemistry. This suppressor deactivation is rationalized in terms of compositional changes in the layer of the chemisorbed anions due to the competition of chloride and MPS (Mercaptopropane Sulfonic Acid) for adsorption sites on the metallic copper surface. MPS is the product of the dissociative SPS adsorption within the preexisting chloride matrix on the copper surface. The non-selectivity in the adsorption behavior of the type-II suppressor is rationalized in terms of anion/cation pairing effects of the poly-cationic suppressor and the anion-modified copper

  11. An unusual characteristic “flower-like” pattern: flash suppressor burns

    OpenAIRE

    Gurcan, Altun

    2012-01-01

    The case on contact shots from firearms with a flash suppressor is rare. When a rifle fitted with a flash suppressor is fired, the emerging soot-laden gas in the barrel escapes from the slits of the flash suppressor. If the shot is contact or near contact, the flash suppressor will produce a characteristic “flower-like” pattern of seared, blackened zones around the entrance. This paper presents the injury pattern of the flash suppressor in a 29-year-old man who committed suicide with a G3 aut...

  12. An unusual characteristic “flower-like” pattern: flash suppressor burns

    Science.gov (United States)

    Gurcan, Altun

    2012-01-01

    The case on contact shots from firearms with a flash suppressor is rare. When a rifle fitted with a flash suppressor is fired, the emerging soot-laden gas in the barrel escapes from the slits of the flash suppressor. If the shot is contact or near contact, the flash suppressor will produce a characteristic “flower-like” pattern of seared, blackened zones around the entrance. This paper presents the injury pattern of the flash suppressor in a 29-year-old man who committed suicide with a G3 automatic infantry rifle. PMID:23935280

  13. Adenovirus small E1A employs the lysine acetylases p300/CBP and tumor suppressor Rb to repress select host genes and promote productive virus infection.

    Science.gov (United States)

    Ferrari, Roberto; Gou, Dawei; Jawdekar, Gauri; Johnson, Sarah A; Nava, Miguel; Su, Trent; Yousef, Ahmed F; Zemke, Nathan R; Pellegrini, Matteo; Kurdistani, Siavash K; Berk, Arnold J

    2014-11-12

    Oncogenic transformation by adenovirus small e1a depends on simultaneous interactions with the host lysine acetylases p300/CBP and the tumor suppressor RB. How these interactions influence cellular gene expression remains unclear. We find that e1a displaces RBs from E2F transcription factors and promotes p300 acetylation of RB1 K873/K874 to lock it into a repressing conformation that interacts with repressive chromatin-modifying enzymes. These repressing p300-e1a-RB1 complexes specifically interact with host genes that have unusually high p300 association within the gene body. The TGF-β, TNF-, and interleukin-signaling pathway components are enriched among such p300-targeted genes. The p300-e1a-RB1 complex condenses chromatin in a manner dependent on HDAC activity, p300 lysine acetylase activity, the p300 bromodomain, and RB K873/K874 and e1a K239 acetylation to repress host genes that would otherwise inhibit productive virus infection. Thus, adenovirus employs e1a to repress host genes that interfere with viral replication. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. F-box-like domain in the polerovirus protein P0 is required for silencing suppressor function

    Science.gov (United States)

    Pazhouhandeh, Maghsoud; Dieterle, Monika; Marrocco, Katia; Lechner, Esther; Berry, Bassam; Brault, Véronique; Hemmer, Odile; Kretsch, Thomas; Richards, Kenneth E.; Genschik, Pascal; Ziegler-Graff, Véronique

    2006-01-01

    Plants employ small RNA-mediated posttranscriptional gene silencing as a virus defense mechanism. In response, plant viruses encode proteins that can suppress RNA silencing, but the mode of action of most such proteins is poorly understood. Here, we show that the silencing suppressor protein P0 of two Arabidopsis-infecting poleroviruses interacts by means of a conserved minimal F-box motif with Arabidopsis thaliana orthologs of S-phase kinase-related protein 1 (SKP1), a component of the SCF family of ubiquitin E3 ligases. Point mutations in the F-box-like motif abolished the P0–SKP1 ortholog interaction, diminished virus pathogenicity, and inhibited the silencing suppressor activity of P0. Knockdown of expression of a SKP1 ortholog in Nicotiana benthamiana rendered the plants resistant to polerovirus infection. Together, the results support a model in which P0 acts as an F-box protein that targets an essential component of the host posttranscriptional gene silencing machinery. PMID:16446454

  15. MicroRNA-103 Promotes Colorectal Cancer by Targeting Tumor Suppressor DICER and PTEN

    Directory of Open Access Journals (Sweden)

    Li Geng

    2014-05-01

    Full Text Available MicroRNAs (miRNAs are a class of small, noncoding RNAs that act as key regulators in various physiological and pathological processes. However, the regulatory mechanisms for miRNAs in colorectal cancer remain largely unknown. Here, we found that miR-103 is up-regulated in colorectal cancer and its overexpression is closely associated with tumor proliferation and migration. In addition, repressing the expression of miR-103 apparently inhibits colorectal cancer cell proliferation and migration in vitro and HCT-116 xenograft tumor growth in vivo. Subsequent software analysis and dual-luciferase reporter assay identified two tumor suppressor genes DICER and PTEN as direct targets of miR-103, and up-regulation of DICER and PTEN obtained similar results to that occurred in the silencing of miR-103. In addition, restoration of DICER and PTEN can inhibit miR-103-induced colorectal cancer cell proliferation and migration. Our data collectively demonstrate that miR-103 is an oncogene miRNA that promotes colorectal cancer proliferation and migration through down-regulation of the tumor suppressor genes DICER and PTEN. Thus, miR-103 may represent a new potential diagnostic and therapeutic target for colorectal cancer treatment.

  16. DLEU2, frequently deleted in malignancy, functions as a critical host gene of the cell cycle inhibitory microRNAs miR-15a and miR-16-1

    International Nuclear Information System (INIS)

    Lerner, Mikael; Harada, Masako; Loven, Jakob; Castro, Juan; Davis, Zadie; Oscier, David; Henriksson, Marie; Sangfelt, Olle; Grander, Dan; Corcoran, Martin M.

    2009-01-01

    The microRNAs miR-15a and miR-16-1 are downregulated in multiple tumor types and are frequently deleted in chronic lymphocytic leukemia (CLL), myeloma and mantle cell lymphoma. Despite their abundance in most cells the transcriptional regulation of miR-15a/16-1 remains unclear. Here we demonstrate that the putative tumor suppressor DLEU2 acts as a host gene of these microRNAs. Mature miR-15a/miR-16-1 are produced in a Drosha-dependent process from DLEU2 and binding of the Myc oncoprotein to two alterative DLEU2 promoters represses both the host gene transcript and levels of mature miR-15a/miR-16-1. In line with a functional role for DLEU2 in the expression of the microRNAs, the miR-15a/miR-16-1 locus is retained in four CLL cases that delete both promoters of this gene and expression analysis indicates that this leads to functional loss of mature miR-15a/16-1. We additionally show that DLEU2 negatively regulates the G1 Cyclins E1 and D1 through miR-15a/miR-16-1 and provide evidence that these oncoproteins are subject to miR-15a/miR-16-1-mediated repression under normal conditions. We also demonstrate that DLEU2 overexpression blocks cellular proliferation and inhibits the colony-forming ability of tumor cell lines in a miR-15a/miR-16-1-dependent way. Together the data illuminate how inactivation of DLEU2 promotes cell proliferation and tumor progression through functional loss of miR-15a/miR-16-1.

  17. Frequent and recent retrotransposition of orthologous genes plays a role in the evolution of sperm glycolytic enzymes

    Directory of Open Access Journals (Sweden)

    de Villena Fernando

    2010-05-01

    Full Text Available Abstract Background The central metabolic pathway of glycolysis converts glucose to pyruvate, with the net production of 2 ATP and 2 NADH per glucose molecule. Each of the ten reactions in this pathway is typically catalyzed by multiple isozymes encoded by a multigene family. Several isozymes in this pathway are expressed only during spermatogenesis, and gene targeting studies indicate that they are essential for sperm function and male fertility in mouse. At least three of the novel glycolytic isozymes are encoded by retrogenes (Pgk2, Aldoart1, and Aldoart2. Their restricted expression profile suggests that retrotransposition may play a significant role in the evolution of sperm glycolytic enzymes. Results We conducted a comprehensive genomic analysis of glycolytic enzymes in the human and mouse genomes and identified several intronless copies for all enzymes in the pathway, except Pfk. Within each gene family, a single orthologous gene was typically retrotransposed frequently and independently in both species. Several retroposed sequences maintained open reading frames (ORFs and/or provided evidence of alternatively spliced exons. We analyzed expression of sequences with ORFs and Gpi1 transcript in mouse spermatogenic cells. Conclusions Our analysis detected frequent, recent, and lineage-specific retrotransposition of orthologous glycolytic enzymes in the human and mouse genomes. Retrotransposition events are associated with LINE/LTR and genomic integration is random. We found evidence for the alternative splicing of parent genes. Many retroposed sequences have maintained ORFs, suggesting a functional role for these genes.

  18. Enhancer-Mediated Oncogenic Function of the Menin Tumor Suppressor in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Koen M.A. Dreijerink

    2017-03-01

    Full Text Available While the multiple endocrine neoplasia type 1 (MEN1 gene functions as a tumor suppressor in a variety of cancer types, we explored its oncogenic role in breast tumorigenesis. The MEN1 gene product menin is involved in H3K4 trimethylation and co-activates transcription. We integrated ChIP-seq and RNA-seq data to identify menin target genes. Our analysis revealed that menin-dependent target gene promoters display looping to distal enhancers that are bound by menin, FOXA1 and GATA3. In this fashion, MEN1 co-regulates a proliferative breast cancer-specific gene expression program in ER+ cells. In primary mammary cells, MEN1 exerts an anti-proliferative function by regulating a distinct expression signature. Our findings clarify the cell-type-specific functions of MEN1 and inform the development of menin-directed treatments for breast cancer.

  19. Frequent alteration of MLL3 frameshift mutations in microsatellite deficient colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Watanabe

    Full Text Available MLL3 is a histone 3-lysine 4 methyltransferase with tumor-suppressor properties that belongs to a family of chromatin regulator genes potentially altered in neoplasia. Mutations in MLL3 were found in a whole genome analysis of colorectal cancer but have not been confirmed by a separate study.We analyzed mutations of coding region and promoter methylation in MLL3 using 126 cases of colorectal cancer. We found two isoforms of MLL3 and DNA sequencing revealed frameshift and other mutations affecting both isoforms of MLL3 in colorectal cancer cells and 19 of 134 (14% primary colorectal samples analyzed. Moreover, frameshift mutations were more common in cases with microsatellite instability (31% both in CRC cell lines and primary tumors. The largest isoform of MLL3 is transcribed from a CpG island-associated promoter that has highly homology with a pseudo-gene on chromosome 22 (psiTPTE22. Using an assay which measured both loci simultaneously we found prominent age related methylation in normal colon (from 21% in individuals less than 25 years old to 56% in individuals older than 70, R = 0.88, p<0.001 and frequent hypermethylation (83% in both CRC cell lines and primary tumors. We next studied the two loci separately and found that age and cancer related methylation was solely a property of the pseudogene CpG island and that the MLL3 loci was unmethylated.We found that frameshift mutations of MLL3 in both CRC cells and primary tumor that were more common in cases with microsatellite instability. Moreover, we have shown CpG island-associated promoter of MLL3 gene has no DNA methylation in CRC cells but also primary tumor and normal colon, and this region has a highly homologous of pseudo gene (psiTPTE22 that was age relate DNA methylation.

  20. Repression of Akt3 gene transcription by the tumor suppressor RIZ1

    OpenAIRE

    Liu, Qingnan; Qu, Xiaotian; Xie, Xiaolei; He, Pei; Huang, Shi

    2018-01-01

    RIZ1 has been studied as a tumor suppressor and may play a role in metabolic diseases related to the Western style diet, such as cancer and obesity. The Akt pathway is known to play a role in both cancer and obesity, and a link between Akt and RIZ1 has also been found. To better understand the role of RIZ1 in obesity and cancer, we investigated how RIZ1 regulates the expression of Akt3. We found that overexpression of RIZ1 in HEK293 cells reduced the expression of Akt3 protein. Luciferase rep...

  1. Inhibitor of differentiation 4 (Id4) is a potential tumor suppressor in prostate cancer

    International Nuclear Information System (INIS)

    Carey, Jason PW; Asirvatham, Ananthi J; Galm, Oliver; Ghogomu, Tandeih A; Chaudhary, Jaideep

    2009-01-01

    Inhibitor of differentiation 4 (Id4), a member of the Id gene family is also a dominant negative regulator of basic helix loop helix (bHLH) transcription factors. Some of the functions of Id4 appear to be unique as compared to its other family members Id1, Id2 and Id3. Loss of Id4 gene expression in many cancers in association with promoter hypermethylation has led to the proposal that Id4 may act as a tumor suppressor. In this study we provide functional evidence that Id4 indeed acts as a tumor suppressor and is part of a cancer associated epigenetic re-programming. Data mining was used to demonstrate Id4 expression in prostate cancer. Methylation specific polymerase chain reaction (MSP) analysis was performed to understand molecular mechanisms associated with Id4 expression in prostate cancer cell lines. The effect of ectopic Id4 expression in DU145 cells was determined by cell cycle analysis (3H thymidine incorporation and FACS), expression of androgen receptor, p53 and cyclin dependent kinase inhibitors p27 and p21 by a combination of RT-PCR, real time-PCR, western blot and immuno-cytochemical analysis. Id4 expression was down-regulated in prostate cancer. Id4 expression was also down-regulated in prostate cancer line DU145 due to promoter hyper-methylation. Ectopic Id4 expression in DU145 prostate cancer cell line led to increased apoptosis and decreased cell proliferation due in part by an S-phase arrest. In addition to S-phase arrest, ectopic Id4 expression in PC3 cells also resulted in prolonged G2/M phase. At the molecular level these changes were associated with increased androgen receptor (AR), p21, p27 and p53 expression in DU145 cells. The results suggest that Id4 acts directly as a tumor suppressor by influencing a hierarchy of cellular processes at multiple levels that leads to a decreased cell proliferation and change in morphology that is possibly mediated through induction of previously silenced tumor suppressors

  2. Frequent mutations of chromatin remodeling genes in transitional cell carcinoma of the bladder

    DEFF Research Database (Denmark)

    Gui, Yaoting; Guo, Guangwu; Huang, Yi

    2011-01-01

    frequently in tumors of low stages and grades, highlighting its potential role in the classification and diagnosis of bladder cancer. Our results provide an overview of the genetic basis of TCC and suggest that aberration of chromatin regulation might be a hallmark of bladder cancer.......Transitional cell carcinoma (TCC) is the most common type of bladder cancer. Here we sequenced the exomes of nine individuals with TCC and screened all the somatically mutated genes in a prevalence set of 88 additional individuals with TCC with different tumor stages and grades. In our study, we...

  3. Viral RNAi suppressor reversibly binds siRNA to outcompete Dicer and RISC via multiple turnover.

    Science.gov (United States)

    Rawlings, Renata A; Krishnan, Vishalakshi; Walter, Nils G

    2011-04-29

    RNA interference is a conserved gene regulatory mechanism employed by most eukaryotes as a key component of their innate immune response to viruses and retrotransposons. During viral infection, the RNase-III-type endonuclease Dicer cleaves viral double-stranded RNA into small interfering RNAs (siRNAs) 21-24 nucleotides in length and helps load them into the RNA-induced silencing complex (RISC) to guide the cleavage of complementary viral RNA. As a countermeasure, many viruses have evolved viral RNA silencing suppressors (RSS) that tightly, and presumably quantitatively, bind siRNAs to thwart RNA-interference-mediated degradation. Viral RSS proteins also act across kingdoms as potential immunosuppressors in gene therapeutic applications. Here we report fluorescence quenching and electrophoretic mobility shift assays that probe siRNA binding by the dimeric RSS p19 from Carnation Italian Ringspot Virus, as well as by human Dicer and RISC assembly complexes. We find that the siRNA:p19 interaction is readily reversible, characterized by rapid binding [(1.69 ± 0.07) × 10(8) M(-)(1) s(-1)] and marked dissociation (k(off)=0.062 ± 0.002 s(-1)). We also observe that p19 efficiently competes with recombinant Dicer and inhibits the formation of RISC-related assembly complexes found in human cell extract. Computational modeling based on these results provides evidence for the transient formation of a ternary complex between siRNA, human Dicer, and p19. An expanded model of RNA silencing indicates that multiple turnover by reversible binding of siRNAs potentiates the efficiency of the suppressor protein. Our predictive model is expected to be applicable to the dosing of p19 as a silencing suppressor in viral gene therapy. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Viral RNAi suppressor reversibly binds siRNA to outcompete Dicer and RISC via multiple-turnover

    Science.gov (United States)

    Rawlings, Renata A.; Krishnan, Vishalakshi; Walter, Nils G.

    2011-01-01

    RNA interference (RNAi) is a conserved gene regulatory mechanism employed by most eukaryotes as a key component of their innate immune response against viruses and retrotransposons. During viral infection, the RNase III-type endonuclease Dicer cleaves viral double-stranded RNA into small interfering RNAs (siRNAs), 21–24 nucleotides in length, and helps load them into the RNA-induced silencing complex (RISC) to guide cleavage of complementary viral RNA. As a countermeasure, many viruses have evolved viral RNA silencing suppressor (RSS) proteins that tightly, and presumably quantitatively, bind siRNAs to thwart RNAi-mediated degradation. Viral RSS proteins also act across kingdoms as potential immunosuppressors in gene therapeutic applications. Here we report fluorescence quenching and electrophoretic mobility shift assays that probe siRNA binding by the dimeric RSS p19 from Carnation Italian Ringspot Virus (CIRV), as well as by human Dicer and RISC assembly complexes. We find that the siRNA:p19 interaction is readily reversible, characterized by rapid binding ((1.69 ± 0.07)×108 M−1s−1) and marked dissociation (koff = 0.062 ± 0.002 s−1). We also observe that p19 efficiently competes with recombinant Dicer and inhibits formation of RISC-related assembly complexes found in human cell extract. Computational modeling based on these results provides evidence for the transient formation of a ternary complex between siRNA, human Dicer, and p19. An expanded model of RNA silencing indicates that multiple-turnover by reversible binding of siRNAs potentiates the efficiency of the suppressor protein. Our predictive model is expected to be applicable to the dosing of p19 as a silencing suppressor in viral gene therapy. PMID:21354178

  5. Measurand transient signal suppressor

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor)

    1994-01-01

    A transient signal suppressor for use in a controls system which is adapted to respond to a change in a physical parameter whenever it crosses a predetermined threshold value in a selected direction of increasing or decreasing values with respect to the threshold value and is sustained for a selected discrete time interval is presented. The suppressor includes a sensor transducer for sensing the physical parameter and generating an electrical input signal whenever the sensed physical parameter crosses the threshold level in the selected direction. A manually operated switch is provided for adapting the suppressor to produce an output drive signal whenever the physical parameter crosses the threshold value in the selected direction of increasing or decreasing values. A time delay circuit is selectively adjustable for suppressing the transducer input signal for a preselected one of a plurality of available discrete suppression time and producing an output signal only if the input signal is sustained for a time greater than the selected suppression time. An electronic gate is coupled to receive the transducer input signal and the timer output signal and produce an output drive signal for energizing a control relay whenever the transducer input is a non-transient signal which is sustained beyond the selected time interval.

  6. Suppressor Effects of Coping Strategies on Resilience

    Science.gov (United States)

    Yoon, Jae ho; Lee, Ji hae; Lee, Chae Yeon; Cho, Minhee; Lee, Sang Min

    2014-01-01

    The purpose of the current study is to demonstrate a significant suppressor effect among coping strategies on resilience. Two different samples were used to replicate the suppressor effect. Participants in the first example were 391 adolescents (middle school students) in Korea, and participants in the second example were 282 young adults…

  7. Enlightened protein: Fhit tumor suppressor protein structure and function and its role in the toxicity of protoporphyrin IX-mediated photodynamic reaction

    International Nuclear Information System (INIS)

    Zawacka-Pankau, Joanna

    2009-01-01

    The Fhit tumor suppressor protein possesses Ap 3 A (diadenosine triphosphate - ApppA) hydrolytic activity in vitro and its gene is found inactive in many pre-malignant states due to gene inactivation. For several years Fhit has been a widely investigated protein as its cellular function still remains largely unsolved. Fhit was shown to act as a molecular 'switch' of cell death via cascade operating on the influence of ATR-Chk1 pathway but also through the mitochondrial apoptotic pathway. Notably, Fhit was reported by our group to enhance the overall eradication effect of porphyrin-mediated photodynamic treatment (PDT). In this review the up-to-date findings on Fhit protein as a tumor suppressor and its role in PDT are presented.

  8. The von Hippel-Lindau tumor suppressor regulates programmed cell death 5-mediated degradation of Mdm2

    NARCIS (Netherlands)

    Essers, P B; Klasson, T D; Pereboom, T C; Mans, D A; Nicastro, M; Boldt, K; Giles, R H; MacInnes, A W

    2015-01-01

    Functional loss of the von Hippel-Lindau (VHL) tumor suppressor protein (pVHL), which is part of an E3-ubiquitin ligase complex, initiates most inherited and sporadic clear-cell renal cell carcinomas (ccRCC). Genetic inactivation of the TP53 gene in ccRCC is rare, suggesting that an alternate

  9. Structural characterization of suppressor lipids by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Rovillos, Mary Joy; Pauling, Josch Konstantin; Hannibal-Bach, Hans Kristian

    2016-01-01

    RATIONALE: Suppressor lipids were originally identified in 1993 and reported to encompass six lipid classes that enable Saccharomyces cerevisiae to live without sphingolipids. Structural characterization, using non-mass spectrometric approaches, revealed that these suppressor lipids are very long...... chain fatty acid (VLCFA)-containing glycerophospholipids with polar head groups that are typically incorporated into sphingolipids. Here we report, for the first time, the structural characterization of the yeast suppressor lipids using high-resolution mass spectrometry. METHODS: Suppressor lipids were...... isolated by preparative chromatography and subjected to structural characterization using hybrid quadrupole time-of-flight and ion trap-orbitrap mass spectrometry. RESULTS: Our investigation recapitulates the overall structural features of the suppressor lipids and provides an in-depth characterization...

  10. The Relationship between FHIT Gene Promoter Methylation and Lung Cancer Risk: 
a Meta-analysis

    Directory of Open Access Journals (Sweden)

    Yichang SUN

    2014-03-01

    Full Text Available Background and objective Tumor-suppressor gene promoter DNA methylation in tumor cells is associated with its reduced expression. FHIT (fragile histindine triad was one of the important tumor suppressor genes which was found hypermethylated in the promoter region in most of tumors. The aim of this study is to evaluate the relationship between FIHT gene promother methylation and lung cancer risk by meta-analysis. Methods By searching Pubmed, CNKI and Wanfang, the open published articles related to FHIT gene promoter methylation and lung carcinoma risk were collected. The odds ratio (OR and range of FHIT gene of cancer tissue of lung cancer patients compared with normal lung tissue, plasma and the bronchial lavage fluid were pooled by statistical software Stata 11.0. Results Eleven studies were finally included in this meta-analysis. The median methylation rate were Pmedian=40.0% (0-68.3%, Pmedian=8.7% (0-35.0%, Pmedian=33.3% (17.1%-38.3% and Pmedian=35.9% (31.1%-50.8% in cancer tissue, NLT, BALF and plasm respectively. The pooled results showed the methylation rate in tumor tissue was much higer than that of NLT OR=5.82 (95%CI: 3.74-9.06, P0.05 and plasma OR=1.41 (95%CI: 0.90-2.20, P>0.05. Conclusion Hypermethylation of FHIT gene promoter region was found more frequent in cancer tissue than that of NLT which may demonstrated association between lung cancer risk and FHIT gene promoter methylation.

  11. The potyviral suppressor of RNA silencing confers enhanced resistance to multiple pathogens

    International Nuclear Information System (INIS)

    Pruss, Gail J.; Lawrence, Christopher B.; Bass, Troy; Li Qingshun Q.; Bowman, Lewis H.; Vance, Vicki

    2004-01-01

    Helper component-protease (HC-Pro) is a plant viral suppressor of RNA silencing, and transgenic tobacco expressing HC-Pro has increased susceptibility to a broad range of viral pathogens. Here we report that these plants also exhibit enhanced resistance to unrelated heterologous pathogens. Tobacco mosaic virus (TMV) infection of HC-Pro-expressing plants carrying the N resistance gene results in fewer and smaller lesions compared to controls without HC-Pro. The resistance to TMV is compromised but not eliminated by expression of nahG, which prevents accumulation of salicylic acid (SA), an important defense signaling molecule. HC-Pro-expressing plants are also more resistant to tomato black ring nepovirus (TBRV) and to the oomycete Peronospora tabacina. Enhanced TBRV resistance is SA-independent, whereas the response to P. tabacina is associated with early induction of markers characteristic of SA-dependent defense. Thus, a plant viral suppressor of RNA silencing enhances resistance to multiple pathogens via both SA-dependent and SA-independent mechanisms

  12. The potyviral suppressor of RNA silencing confers enhanced resistance to multiple pathogens.

    Science.gov (United States)

    Pruss, Gail J; Lawrence, Christopher B; Bass, Troy; Li, Qingshun Q; Bowman, Lewis H; Vance, Vicki

    2004-03-01

    Helper component-protease (HC-Pro) is a plant viral suppressor of RNA silencing, and transgenic tobacco expressing HC-Pro has increased susceptibility to a broad range of viral pathogens. Here we report that these plants also exhibit enhanced resistance to unrelated heterologous pathogens. Tobacco mosaic virus (TMV) infection of HC-Pro-expressing plants carrying the N resistance gene results in fewer and smaller lesions compared to controls without HC-Pro. The resistance to TMV is compromised but not eliminated by expression of nahG, which prevents accumulation of salicylic acid (SA), an important defense signaling molecule. HC-Pro-expressing plants are also more resistant to tomato black ring nepovirus (TBRV) and to the oomycete Peronospora tabacina. Enhanced TBRV resistance is SA-independent, whereas the response to P. tabacina is associated with early induction of markers characteristic of SA-dependent defense. Thus, a plant viral suppressor of RNA silencing enhances resistance to multiple pathogens via both SA-dependent and SA-independent mechanisms.

  13. Transient Co-Expression of Post-Transcriptional Gene Silencing Suppressors for Increased in Planta Expression of a Recombinant Anthrax Receptor Fusion Protein

    Directory of Open Access Journals (Sweden)

    Kittipong Rattanaporn

    2011-08-01

    Full Text Available Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin, CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA domain of human capillary morphogenesis 2 (CMG2, an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG. We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS: p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI, with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI.

  14. Transient co-expression of post-transcriptional gene silencing suppressors for increased in planta expression of a recombinant anthrax receptor fusion protein.

    Science.gov (United States)

    Arzola, Lucas; Chen, Junxing; Rattanaporn, Kittipong; Maclean, James M; McDonald, Karen A

    2011-01-01

    Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin), CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA) domain of human capillary morphogenesis 2 (CMG2), an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG). We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS): p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI), with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI.

  15. Thrombospondin-4 is a putative tumour-suppressor gene in colorectal cancer that exhibits age-related methylation

    International Nuclear Information System (INIS)

    Greco, Sonia A; Leggett, Barbara A; Whitehall, Vicki LJ; Chia, June; Inglis, Kelly J; Cozzi, Sarah-Jane; Ramsnes, Ingunn; Buttenshaw, Ronald L; Spring, Kevin J; Boyle, Glen M; Worthley, Daniel L

    2010-01-01

    colon. THBS4 shows increased methylation in colorectal cancer, but this is not strongly associated with altered gene expression, either because methylation has not always reached a critical level or because other factors influence THBS4 expression. THBS4 may act as a tumour suppressor gene, demonstrated by its suppression of tumour colony formation in vitro. THBS4 methylation is detectable in normal colonic mucosa and its level may be a biomarker for the occurrence of adenomas and carcinoma

  16. Thrombospondin-4 is a putative tumour-suppressor gene in colorectal cancer that exhibits age-related methylation

    Directory of Open Access Journals (Sweden)

    Greco Sonia A

    2010-09-01

    negatively with the occurrence of adenomas elsewhere in the colon. Conclusions THBS4 shows increased methylation in colorectal cancer, but this is not strongly associated with altered gene expression, either because methylation has not always reached a critical level or because other factors influence THBS4 expression. THBS4 may act as a tumour suppressor gene, demonstrated by its suppression of tumour colony formation in vitro. THBS4 methylation is detectable in normal colonic mucosa and its level may be a biomarker for the occurrence of adenomas and carcinoma.

  17. The metastasis suppressor gene KISS-1 regulates osteosarcoma apoptosis and autophagy processes.

    Science.gov (United States)

    Yin, Yiran; Tang, Lian; Shi, Lei

    2017-03-01

    The expression of the metastasis suppressor gene KISS-1 in osteosarcoma cells during apoptosis and autophagy was evaluated. MG-63 osteosarcoma cells were transfected with either KISS-1 overexpression or KISS-1 knockdown expression vector in vitro, and compared with cell lines transfected with empty vector. After 12, 24, 48 and 72 h of cell culture, the cell proliferation was examined. The MTT method was used to detect apoptosis by flow cytometry, and the mRNA levels of apoptosis and autophagy markers caspase-3, Bcl-2, Bax, LC3 and Beclin1 were assessed by RT-PCR. Our results showed that cells in the control and low expression group kept proliferating during the cell culture period of 72 h, while the cells in the overexpression group progressively decreased in number. Also, the proliferation rate of the low expression group was significantly higher than that of the control group. The relative mRNA expression levels of caspase-3 and Bax mRNA in the control and low expression group showed no change (the expression was lowest in the low expression group). Moreover, the mRNA level of Bcl-2 increased in both cell groups. The mRNA expression levels of caspase-3 and Bax in the overexpression group were increased, and the level of Bcl-2 was reduced significantly. At the same time, the relative expression level of LC3 and Beclin1 mRNA in the control and low expression groups remained the same, and that of the overexpression group increased. The mRNA levels of LC3 and Beclin1 in the overexpression group were the highest, and that of the low expression group the lowest. The differences were statistically significant (Posteosarcoma in vitro, probably by accelerating the processes of apoptosis and autophagy in the cells.

  18. Radiosensitivity and genes

    Energy Technology Data Exchange (ETDEWEB)

    Qiyue, Hu; Mingyue, Lun [Suzhou Medical Coll., JS (China)

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G{sub 1} phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM{sub 9} cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation.

  19. Radiosensitivity and genes

    International Nuclear Information System (INIS)

    Hu Qiyue; Lun Mingyue

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G 1 phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM 9 cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation

  20. NDRG2 is a candidate tumor-suppressor for oral squamous-cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Hiroshi; Kondo, Yuudai [Division of Oral and Maxillofacial Surgery, Medicine of Sensory and Motor Organs, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Nakahata, Shingo; Hamasaki, Makoto [Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Sakoda, Sumio [Division of Oral and Maxillofacial Surgery, Medicine of Sensory and Motor Organs, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan); Morishita, Kazuhiro, E-mail: kmorishi@med.miyazaki-u.ac.jp [Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-gun, Miyazaki 889-1692 (Japan)

    2010-01-22

    Oral cancer is one of the most common cancers worldwide, and squamous-cell carcinoma (OSCC) is the most common phenotype of oral cancer. Although patients with OSCC have poor survival rates and a high incidence of metastasis, the molecular mechanisms of OSCC development have not yet been elucidated. This study investigated whether N-myc downstream-regulated gene 2 (NDRG2) contributes to the carcinogenesis of OSCC, as NDRG2 is reported to be a candidate tumor-suppressor gene in a wide variety of cancers. The down-regulation of NDRG2 mRNA, which was dependent on promoter methylation, was seen in the majority of OSCC cases and in several cases of precancerous leukoplakia with dysplasia. Induction of NDRG2 expression in an HSC-3/OSCC cell line significantly inhibited cell proliferation and decreased colony formation ability on soft agar. The majority of OSCC cell lines showed an activation of PI3K/Akt signaling, and enforced expression of NDRG2 in HSC-3 cells decreased the level of phosphorylated Akt at Serine 473 (p-Akt). Immunohistochemical p-Akt staining was detected in 56.5% of the OSCC tumors, and 80.4% of the tumors were negative for NDRG2 staining. Moreover, positive p-Akt staining was inversely correlated with decreased NDRG2 expression in OSCC tumors with moderate to poor differentiation (p < 0.005). Therefore, NDRG2 is a candidate tumor-suppressor gene for OSCC development and probably contributes to the tumorigenesis of OSCC partly via the modulation of Akt signaling.

  1. Promoter hypermethylation of KLF4 inactivates its tumor suppressor function in cervical carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Wen-Ting Yang

    Full Text Available OBJECTIVE: The KLF4 gene has been shown to be inactivated in cervical carcinogenesis as a tumor suppressor. However, the mechanism of KLF4 silencing in cervical carcinomas has not yet been identified. DNA methylation plays a key role in stable suppression of gene expression. METHODS: The methylation status of the KLF4 promoter CpG islands was analyzed by bisulfite sequencing (BSQ in tissues of normal cervix and cervical cancer. KLF4 gene expression was detected by RT-PCR, immunohistochemistry and western blot. KLF4 promoter methylation in cervical cancer cell line was determined by BSQ and methylation-specific polymerase chain reaction (MS-PCR. Cell proliferation ability was detected by cell growth curve and MTT assay. RESULTS: The methylated allele was found in 41.90% of 24 cervical cancer tissues but only in 11.11% of 11 normal cervix tissues (P<0.005. KLF4 mRNA levels were significantly reduced in cervical cancer tissues compared with normal cervix tissues (P<0.01 and KLF4 mRNA expression showed a significant negative correlation with the promoter hypermethylation (r = -0.486, P = 0.003. Cervical cancer cell lines also showed a significant negative correlation between KLF4 expression and hypermethylation. After treatment with the demethylating agent 5-Azacytidine (5-Aza, the expression of KLF4 in the cervical cancer cell lines at both mRNA and protein levels was drastically increased, the cell proliferation ability was inhibited and the chemosensitivity for cisplatin was significantly increased. CONCLUSION: KLF4 gene is inactivated by methylation-induced silencing mechanisms in a large subset of cervical carcinomas and KLF4 promoter hypermethylation inactivates the gene's function as a tumor suppressor in cervical carcinogenesis.

  2. The von Hippel-Lindau tumor suppressor gene inhibits hepatocyte growth factor/scatter factor-induced invasion and branching morphogenesis in renal carcinoma cells.

    Science.gov (United States)

    Koochekpour, S; Jeffers, M; Wang, P H; Gong, C; Taylor, G A; Roessler, L M; Stearman, R; Vasselli, J R; Stetler-Stevenson, W G; Kaelin, W G; Linehan, W M; Klausner, R D; Gnarra, J R; Vande Woude, G F

    1999-09-01

    Loss of function in the von Hippel-Lindau (VHL) tumor suppressor gene occurs in familial and most sporadic renal cell carcinomas (RCCs). VHL has been linked to the regulation of cell cycle cessation (G(0)) and to control of expression of various mRNAs such as for vascular endothelial growth factor. RCC cells express the Met receptor tyrosine kinase, and Met mediates invasion and branching morphogenesis in many cell types in response to hepatocyte growth factor/scatter factor (HGF/SF). We examined the HGF/SF responsiveness of RCC cells containing endogenous mutated (mut) forms of the VHL protein (VHL-negative RCC) with that of isogenic cells expressing exogenous wild-type (wt) VHL (VHL-positive RCC). We found that VHL-negative 786-0 and UOK-101 RCC cells were highly invasive through growth factor-reduced (GFR) Matrigel-coated filters and exhibited an extensive branching morphogenesis phenotype in response to HGF/SF in the three-dimensional (3D) GFR Matrigel cultures. In contrast, the phenotypes of A498 VHL-negative RCC cells were weaker, and isogenic RCC cells ectopically expressing wt VHL did not respond at all. We found that all VHL-negative RCC cells expressed reduced levels of tissue inhibitor of metalloproteinase 2 (TIMP-2) relative to the wt VHL-positive cells, implicating VHL in the regulation of this molecule. However, consistent with the more invasive phenotype of the 786-0 and UOK-101 VHL-negative RCC cells, the levels of TIMP-1 and TIMP-2 were reduced and levels of the matrix metalloproteinases 2 and 9 were elevated compared to the noninvasive VHL-positive RCC cells. Moreover, recombinant TIMPs completely blocked HGF/SF-mediated branching morphogenesis, while neutralizing antibodies to the TIMPs stimulated HGF/SF-mediated invasion in vitro. Thus, the loss of the VHL tumor suppressor gene is central to changes that control tissue invasiveness, and a more invasive phenotype requires additional genetic changes seen in some but not all RCC lines. These

  3. A multicopy suppressor screening approach as a means to identify antibiotic resistance determinant candidates in Yersinia pestis

    Directory of Open Access Journals (Sweden)

    Moy Richard L

    2008-07-01

    Full Text Available Abstract Background Yersinia pestis is the causative agent of plague and a potential agent of bioterrorism and biowarfare. The plague biothreat and the emergence of multidrug-resistant plague underscore the need to increase our understanding of the intrinsic potential of Y. pestis for developing antimicrobial resistance and to anticipate the mechanisms of resistance that may emerge in Y. pestis. Identification of Y. pestis genes that, when overexpressed, are capable of reducing antibiotic susceptibility is a useful strategy to expose genes that this pathogen may rely upon to evolve antibiotic resistance via a vertical modality. In this study, we explored the use of a multicopy suppressor, Escherichia coli host-based screening approach as a means to expose antibiotic resistance determinant candidates in Y. pestis. Results We constructed a multicopy plasmid-based, Y. pestis genome-wide expression library of nearly 16,000 clones in E. coli and screened the library for suppressors of the antimicrobial activity of ofloxacin, a fluoroquinolone antibiotic. The screen permitted the identification of a transcriptional regulator-encoding gene (robAYp that increased the MIC99 of ofloxacin by 23-fold when overexpressed from a multicopy plasmid in Y. pestis. Additionally, we found that robAYp overexpression in Y. pestis conferred low-level resistance to many other antibiotics and increased organic solvent tolerance. Overexpression of robAYp also upregulated the expression of several efflux pumps in Y. pestis. Conclusion Our study provides proof of principle for the use of multicopy suppressor screening based on the tractable and easy-to-manipulate E. coli host as a means to identify antibiotic resistance determinant candidates of Y. pestis.

  4. Analysis of Suppressor of Cytokine Signaling 2 Gene (SOCS2 Polymorphism in Different Dog Breeds

    Directory of Open Access Journals (Sweden)

    Martina Miluchová

    2011-05-01

    Full Text Available SOCS2 is a negative regulator of growth hormone signaling. The deletion of SOCS2 in mice results in a 30-50% increase in post-natal growth. The aim of the paper was to identify of suppressor of cytokine signaling 2 gene (SOCS2 polymorphism in different dog breeds. The material involved 77 dogs from 14 different breeds. Canine genomic DNA was isolated from saliva by modified method with using DNAzol® (Molecular Research Center and linear polyacrylamide (LPA carrier and from blood by using NucleospinBlood (Macherey-Nagel and used in order to estimate SOCS2 genotypes by PCR-RFLP method. The PCR products were digested with TaqI restriction enzyme. The T allele was distributed among large dog breeds (Czech pointer, Golden retriever, Rottweiler with an allele frequency ranging from 0.2857 to 1.00. In the population of Czech pointer we detected all genotypes. There were detected homozygote genotype GG with frequency 0.5476, heterozygote genotype GT with frequency 0.3333 and homozygote genotype TT with frequency 0.1191. Results point out that frequency of G allele was high and was represented 0.7143. Frequency of T allele was 0.2857. In Rottweiler was detected homozygote genotype TT. Genotypes GG and GT has not been observed. In Golden retriever we detected only heterozygote genotype GT.

  5. Tumor Suppressor RARRES1 Regulates DLG2, PP2A, VCP, EB1, and Ankrd26

    Directory of Open Access Journals (Sweden)

    Ziad J. Sahab, Michael D. Hall, Lihua Zhang, Amrita K. Cheema, Stephen W. Byers

    2010-01-01

    Full Text Available Retinoic Acid Receptor Responder (RARRES1 initially identified as a novel retinoic acid receptor regulated gene in the skin is a putative tumor suppressor of unknown function. RARRES1 was knocked down in immortalized human prostatic epithelial cell line PWR-1E cells and differential protein expression was identified using differential in-gel electrophoresis (DIGE followed by matrix-assisted laser desorption ionization (MALDI mass spectrometry and western Blot analysis excluding highly abundant proteins routinely identified in almost all proteomics projects. Knock-down of RARRES1: 1- down-regulates PP2A, an enzyme involved in the negative regulation of the growth hormone-stimulated signal transduction pathways; 2- down-regulates Valosin-containing protein causing impaired autophagy; 3- up-regulates the tumor suppressor disks large 2; 4- up-regulates Ankrd26 that belongs to the POTE family of genes that are highly expressed in cancer patients with poor outcome; and 5- down-regulates EB1, a protein that is involved in spindle dynamics and chromosome alignment during mitosis.

  6. The Fbw7 tumor suppressor targets KLF5 for ubiquitin-mediated degradation and suppresses breast cell proliferation.

    Science.gov (United States)

    Zhao, Dong; Zheng, Han-Qiu; Zhou, Zhongmei; Chen, Ceshi

    2010-06-01

    Fbw7 is a tumor suppressor frequently inactivated in cancers. The KLF5 transcription factor promotes breast cell proliferation and tumorigenesis through upregulating FGF-BP. The KLF5 protein degrades rapidly through the ubiquitin proteasome pathway. Here, we show that the Skp1-CUL1-Fbw7 E3 ubiquitin ligase complex (SCF(Fbw7)) targets KLF5 for ubiquitin-mediated degradation in a GSK3beta-mediated KLF5 phosphorylation-dependent manner. Mutation of the critical S303 residue in the KLF5 Cdc4 phospho-degrons motif ((303)SPPSS) abolishes the protein interaction, ubiquitination, and degradation by Fbw7. Inactivation of endogenous Fbw7 remarkably increases the endogenous KLF5 protein abundances. Endogenous Fbw7 suppresses the FGF-BP gene expression and breast cell proliferation through targeting KLF5 for degradation. These findings suggest that Fbw7 inhibits breast cell proliferation at least partially through targeting KLF5 for proteolysis. This new regulatory mechanism of KLF5 degradation may result in useful diagnostic and therapeutic targets for breast cancer and other cancers. Copyright 2010 AACR.

  7. Transducer of ERBB2.1 (TOB1) as a Tumor Suppressor: A Mechanistic Perspective.

    Science.gov (United States)

    Lee, Hun Seok; Kundu, Juthika; Kim, Ryong Nam; Shin, Young Kee

    2015-12-15

    Transducer of ERBB2.1 (TOB1) is a tumor-suppressor protein, which functions as a negative regulator of the receptor tyrosine-kinase ERBB2. As most of the other tumor suppressor proteins, TOB1 is inactivated in many human cancers. Homozygous deletion of TOB1 in mice is reported to be responsible for cancer development in the lung, liver, and lymph node, whereas the ectopic overexpression of TOB1 shows anti-proliferation, and a decrease in the migration and invasion abilities on cancer cells. Biochemical studies revealed that the anti-proliferative activity of TOB1 involves mRNA deadenylation and is associated with the reduction of both cyclin D1 and cyclin-dependent kinase (CDK) expressions and the induction of CDK inhibitors. Moreover, TOB1 interacts with an oncogenic signaling mediator, β-catenin, and inhibits β-catenin-regulated gene transcription. TOB1 antagonizes the v-akt murine thymoma viral oncogene (AKT) signaling and induces cancer cell apoptosis by activating BCL2-associated X (BAX) protein and inhibiting the BCL-2 and BCL-XL expressions. The tumor-specific overexpression of TOB1 results in the activation of other tumor suppressor proteins, such as mothers against decapentaplegic homolog 4 (SMAD4) and phosphatase and tensin homolog-10 (PTEN), and blocks tumor progression. TOB1-overexpressing cancer cells have limited potential of growing as xenograft tumors in nude mice upon subcutaneous implantation. This review addresses the molecular basis of TOB1 tumor suppressor function with special emphasis on its regulation of intracellular signaling pathways.

  8. Transducer of ERBB2.1 (TOB1 as a Tumor Suppressor: A Mechanistic Perspective

    Directory of Open Access Journals (Sweden)

    Hun Seok Lee

    2015-12-01

    Full Text Available Transducer of ERBB2.1 (TOB1 is a tumor-suppressor protein, which functions as a negative regulator of the receptor tyrosine-kinase ERBB2. As most of the other tumor suppressor proteins, TOB1 is inactivated in many human cancers. Homozygous deletion of TOB1 in mice is reported to be responsible for cancer development in the lung, liver, and lymph node, whereas the ectopic overexpression of TOB1 shows anti-proliferation, and a decrease in the migration and invasion abilities on cancer cells. Biochemical studies revealed that the anti-proliferative activity of TOB1 involves mRNA deadenylation and is associated with the reduction of both cyclin D1 and cyclin-dependent kinase (CDK expressions and the induction of CDK inhibitors. Moreover, TOB1 interacts with an oncogenic signaling mediator, β-catenin, and inhibits β-catenin-regulated gene transcription. TOB1 antagonizes the v-akt murine thymoma viral oncogene (AKT signaling and induces cancer cell apoptosis by activating BCL2-associated X (BAX protein and inhibiting the BCL-2 and BCL-XL expressions. The tumor-specific overexpression of TOB1 results in the activation of other tumor suppressor proteins, such as mothers against decapentaplegic homolog 4 (SMAD4 and phosphatase and tensin homolog-10 (PTEN, and blocks tumor progression. TOB1-overexpressing cancer cells have limited potential of growing as xenograft tumors in nude mice upon subcutaneous implantation. This review addresses the molecular basis of TOB1 tumor suppressor function with special emphasis on its regulation of intracellular signaling pathways.

  9. NF-{kappa}B p50 promotes tumor cell invasion through negative regulation of invasion suppressor gene CRMP-1 in human lung adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Gao [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Yeh, P Y [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China); Lu, Y -S [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan, ROC (China); Chang, W C [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Kuo, M -L [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Cheng, A -L [Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University, Hospital, Taipei, Taiwan (China); Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 10016, Taiwan (China)], E-mail: alcheng@ntu.edu.tw

    2008-11-14

    Lung adenocarcinoma Cl1-5 cells were selected from parental Cl1-0 cells based on their high metastatic potential. In a previous study, CRMP-1, an invasion suppressor gene, was shown to be suppressed in Cl1-5 cells. However, the regulation of CRMP-1 expression has not been explored. In this study, we showed nuclear factor-{kappa}B controls CRMP-1 expression. The electromobility shift assay showed that while Cl1-0 cells exhibited low NF-{kappa}B activity in response to TNF-{alpha}, an abundance of basal and TNF-{alpha}-induced NF-{kappa}B-DNA complex was detected in Cl1-5 cells. Supershift-coupled EMSA and Western blotting of nuclear proteins, however, revealed p50 protein, but not classic p65/p50 heterodimer in the complex. ChIP and EMSA demonstrated that p50 binds to a {kappa}B site residing between -1753 and -1743 of the CRMP-1 promoter region. Transfection of antisense p50 gene into Cl1-5 cells increased the CRMP-1 protein level and decreased the invasive activity of Cl1-5 cells.

  10. NF-κB p50 promotes tumor cell invasion through negative regulation of invasion suppressor gene CRMP-1 in human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Gao Ming; Yeh, P.Y.; Lu, Y.-S.; Chang, W.C.; Kuo, M.-L.; Cheng, A.-L.

    2008-01-01

    Lung adenocarcinoma Cl1-5 cells were selected from parental Cl1-0 cells based on their high metastatic potential. In a previous study, CRMP-1, an invasion suppressor gene, was shown to be suppressed in Cl1-5 cells. However, the regulation of CRMP-1 expression has not been explored. In this study, we showed nuclear factor-κB controls CRMP-1 expression. The electromobility shift assay showed that while Cl1-0 cells exhibited low NF-κB activity in response to TNF-α, an abundance of basal and TNF-α-induced NF-κB-DNA complex was detected in Cl1-5 cells. Supershift-coupled EMSA and Western blotting of nuclear proteins, however, revealed p50 protein, but not classic p65/p50 heterodimer in the complex. ChIP and EMSA demonstrated that p50 binds to a κB site residing between -1753 and -1743 of the CRMP-1 promoter region. Transfection of antisense p50 gene into Cl1-5 cells increased the CRMP-1 protein level and decreased the invasive activity of Cl1-5 cells

  11. Understanding the tumor suppressor PTEN in chronic alcoholism and hepatocellular carcinoma.

    Science.gov (United States)

    Shearn, Colin T; Petersen, Dennis R

    2015-01-01

    The tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a phosphatidylinositol (PtdIns) phosphatase that regulates Akt activation via PtdIns 3 kinase. Changes in PTEN expression and/or activity have been identified in a variety of chronic hepatocellular disorders including obesity, NAFLD, NASH, and alcoholism. In cancer biology, PTEN is frequently mutated or deleted in a wide variety of tumors. Mutations, decreased promoter activity, and decreased expression in PTEN are frequently identified in patients with hepatocellular carcinoma. While the majority of research on PTEN concerns obesity and NASH, PTEN clearly has a role in hepatic insulin sensitivity and in the development of steatosis during chronic alcoholism. Yet, in chronic alcoholics and HCC, very little is known concerning PTEN mutation/deletion or low PTEN expression. This review is focused on an overview of the current knowledge on molecular mechanisms of dysregulation of PTEN expression/activity in the liver and their relationship to development of ethanol-induced hepatocellular damage and cancer.

  12. MicroRNA-34a is a potent tumor suppressor molecule in vivo in neuroblastoma.

    LENUS (Irish Health Repository)

    Tivnan, Amanda

    2011-01-01

    Neuroblastoma is a paediatric cancer which originates from precursor cells of the sympathetic nervous system and accounts for 15% of childhood cancer mortalities. With regards to the role of miRNAs in neuroblastoma, miR-34a, mapping to a chromosome 1p36 region that is commonly deleted, has been found to act as a tumor suppressor through targeting of numerous genes associated with cell proliferation and apoptosis.

  13. Cumulative Epigenetic Abnormalities in Host Genes with Viral and Microbial Infection during Initiation and Progression of Malignant Lymphoma/Leukemia

    International Nuclear Information System (INIS)

    Oka, Takashi; Sato, Hiaki; Ouchida, Mamoru; Utsunomiya, Atae; Yoshino, Tadashi

    2011-01-01

    Although cancers have been thought to be predominantly driven by acquired genetic changes, it is becoming clear that microenvironment-mediated epigenetic alterations play important roles. Aberrant promoter hypermethylation is a prevalent phenomenon in human cancers as well as malignant lymphoma/leukemia. Tumor suppressor genes become frequent targets of aberrant hypermethylation in the course of gene-silencing due to the increased and deregulated DNA methyltransferases (DNMTs). The purpose of this article is to review the current status of knowledge about the contribution of cumulative epigenetic abnormalities of the host genes after microbial and virus infection to the crisis and progression of malignant lymphoma/leukemia. In addition, the relevance of this knowledge to malignant lymphoma/leukemia assessment, prevention and early detection will be discussed

  14. Cumulative Epigenetic Abnormalities in Host Genes with Viral and Microbial Infection during Initiation and Progression of Malignant Lymphoma/Leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Takashi, E-mail: oka@md.okayama-u.ac.jp [Department of Pathology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8558 (Japan); Sato, Hiaki [Department of Medical Technology, Graduate School of Health Science, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558 (Japan); Ouchida, Mamoru [Department of Molecular Genetics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8558 (Japan); Utsunomiya, Atae [Department of Hematology, Imamura Bun-in Hospital, 11-23 Kamoike Shinnmachi, Kagoshima, 890-0064 (Japan); Yoshino, Tadashi [Department of Pathology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8558 (Japan)

    2011-02-04

    Although cancers have been thought to be predominantly driven by acquired genetic changes, it is becoming clear that microenvironment-mediated epigenetic alterations play important roles. Aberrant promoter hypermethylation is a prevalent phenomenon in human cancers as well as malignant lymphoma/leukemia. Tumor suppressor genes become frequent targets of aberrant hypermethylation in the course of gene-silencing due to the increased and deregulated DNA methyltransferases (DNMTs). The purpose of this article is to review the current status of knowledge about the contribution of cumulative epigenetic abnormalities of the host genes after microbial and virus infection to the crisis and progression of malignant lymphoma/leukemia. In addition, the relevance of this knowledge to malignant lymphoma/leukemia assessment, prevention and early detection will be discussed.

  15. Inhibitor of differentiation 4 (Id4 is a potential tumor suppressor in prostate cancer

    Directory of Open Access Journals (Sweden)

    Carey Jason PW

    2009-06-01

    Full Text Available Abstract Background Inhibitor of differentiation 4 (Id4, a member of the Id gene family is also a dominant negative regulator of basic helix loop helix (bHLH transcription factors. Some of the functions of Id4 appear to be unique as compared to its other family members Id1, Id2 and Id3. Loss of Id4 gene expression in many cancers in association with promoter hypermethylation has led to the proposal that Id4 may act as a tumor suppressor. In this study we provide functional evidence that Id4 indeed acts as a tumor suppressor and is part of a cancer associated epigenetic re-programming. Methods Data mining was used to demonstrate Id4 expression in prostate cancer. Methylation specific polymerase chain reaction (MSP analysis was performed to understand molecular mechanisms associated with Id4 expression in prostate cancer cell lines. The effect of ectopic Id4 expression in DU145 cells was determined by cell cycle analysis (3H thymidine incorporation and FACS, expression of androgen receptor, p53 and cyclin dependent kinase inhibitors p27 and p21 by a combination of RT-PCR, real time-PCR, western blot and immuno-cytochemical analysis. Results Id4 expression was down-regulated in prostate cancer. Id4 expression was also down-regulated in prostate cancer line DU145 due to promoter hyper-methylation. Ectopic Id4 expression in DU145 prostate cancer cell line led to increased apoptosis and decreased cell proliferation due in part by an S-phase arrest. In addition to S-phase arrest, ectopic Id4 expression in PC3 cells also resulted in prolonged G2/M phase. At the molecular level these changes were associated with increased androgen receptor (AR, p21, p27 and p53 expression in DU145 cells. Conclusion The results suggest that Id4 acts directly as a tumor suppressor by influencing a hierarchy of cellular processes at multiple levels that leads to a decreased cell proliferation and change in morphology that is possibly mediated through induction of previously

  16. Up-regulation of tumor suppressor genes by exogenous dhC16-Cer contributes to its anti-cancer activity in primary effusion lymphoma.

    Science.gov (United States)

    Cao, Yueyu; Qiao, Jing; Lin, Zhen; Zabaleta, Jovanny; Dai, Lu; Qin, Zhiqiang

    2017-02-28

    Primary effusion lymphoma (PEL) is a rare and highly aggressive B-cell malignancy with Kaposi's sarcoma-associated herpesvirus (KSHV) infection, while lack of effective therapies. Our recent data indicated that targeting the sphingolipid metabolism by either sphingosine kinase inhibitor or exogenous ceramide species induces PEL cell apoptosis and suppresses tumor progression in vivo. However, the underlying mechanisms for these exogenous ceramides "killing" PEL cells remain largely unknown. Based on the microarray analysis, we found that exogenous dhC16-Cer treatment affected the expression of many cellular genes with important functions within PEL cells such as regulation of cell cycle, cell survival/proliferation, and apoptosis/anti-apoptosis. Interestingly, we found that a subset of tumor suppressor genes (TSGs) was up-regulated from dhC16-Cer treated PEL cells. One of these elevated TSGs, Thrombospondin-1 (THBS1) was required for dhC16-Cer induced PEL cell cycle arrest. Moreover, dhC16-Cer up-regulation of THBS1 was through the suppression of multiple KSHV microRNAs expression. Our data demonstrate that exogenous ceramides display anti-cancer activities for PEL through regulation of both host and oncogenic virus factors.

  17. Meta-analysis of promoter methylation in eight tumor-suppressor genes and its association with the risk of thyroid cancer.

    Directory of Open Access Journals (Sweden)

    Fatemeh Khatami

    Full Text Available Promoter methylation in a number of tumor-suppressor genes (TSGs can play crucial roles in the development of thyroid carcinogenesis. The focus of the current meta-analysis was to determine the impact of promoter methylation of eight selected candidate TSGs on thyroid cancer and to identify the most important molecules in this carcinogenesis pathway. A comprehensive search was performed using Pub Med, Scopus, and ISI Web of Knowledge databases, and eligible studies were included. The methodological quality of the included studies was evaluated according to the Newcastle Ottawa scale table and pooled odds ratios (ORs; 95% confidence intervals (CIs were used to estimate the strength of the associations with Stata 12.0 software. Egger's and Begg's tests were applied to detect publication bias, in addition to the "Metatrim" method. A total of 55 articles were selected, and 135 genes with altered promoter methylation were found. Finally, we included eight TSGs that were found in more than four studies (RASSF1, TSHR, PTEN, SLC5A, DAPK, P16, RARβ2, and CDH1. The order of the pooled ORs for these eight TSGs from more to less significant was CDH1 (OR = 6.73, SLC5 (OR = 6.15, RASSF1 (OR = 4.16, PTEN (OR = 3.61, DAPK (OR = 3.51, P16 (OR = 3.31, TSHR (OR = 2.93, and RARβ2 (OR = 1.50. Analyses of publication bias and sensitivity confirmed that there was very little bias. Thus, our findings showed that CDH1 and SCL5A8 genes were associated with the risk of thyroid tumor genesis.

  18. 'Cancer genes and their expression; blueprint to future improvements in radiation protection?'

    International Nuclear Information System (INIS)

    Paterson, M.C.

    1996-01-01

    The field of molecular oncology is reviewed, with some reference to the effects of ionizing radiation. There are three classes of cancer genes: oncogenes, tumor suppressor genes, and modulator genes. Proto-oncogenes control the synthesis of proteins which regulate cell division; these proto-oncogenes, of which about 100 have been identified, become oncogenes when damaged. Oncogenes are dominant. Only about a dozen tumor-suppressor genes have been identified; they are recessive. One example of a tumor suppressor gene is that producing p53 protein, which shuts down DNA replication temporarily to allow time for enzymatic repair of damage resulting from radiation or other damaging agents. Modulator genes are a heterogeneous class, including those genes that facilitate the destruction of pre-malignant cells by immune surveillance. Modulator genes also include those responsible for DNA repair. The study of DNA repair and its defects has made recent strides, and 12 participating enzymes have now been identified. It may soon be possible to monitor low-level radiation effects in individuals at the molecular level. Perhaps individuals will be monitored for their 'carcinogen exposure response' index, giving them the opportunity to adjust their lifestyles and occupations accordingly. 20 refs

  19. LACTB, a novel epigenetic silenced tumor suppressor, inhibits colorectal cancer progression by attenuating MDM2-mediated p53 ubiquitination and degradation.

    Science.gov (United States)

    Zeng, Kaixuan; Chen, Xiaoxiang; Hu, Xiuxiu; Liu, Xiangxiang; Xu, Tao; Sun, Huiling; Pan, Yuqin; He, Bangshun; Wang, Shukui

    2018-06-13

    Colorectal cancer (CRC) is one of the most common aggressive malignancies. Like other solid tumors, inactivation of tumor suppressor genes and activation of oncogenes occur during CRC development and progression. Recently, a novel tumor suppressor, LACTB, was proposed to inhibit tumor progression, but the functional and clinical significance of this tumor suppressor in CRC remains unexplored. Herein, we found LACTB was significantly downregulated in CRC due to promoter methylation and histone deacetylation, which was associated with metastasis and advanced clinical stage. CRC patients with low LACTB expression had poorer overall survival and LACTB also determined to be an independent prognostic factor for poorer outcome. Ectopic expression of LACTB suppressed CRC cells proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro and inhibited CRC growth and metastasis in vivo, while knockout of LACTB by CRISPR/Cas9 gene editing technique resulted in an opposite phenotype. Interestingly, LACTB could exert antitumorigenic effect only in HCT116 and HCT8 cells harboring wild-type TP53, but not in HT29 and SW480 cells harboring mutant TP53 or HCT116 p53 -/- cells. Mechanistic studies demonstrated that LACTB could directly bind to the C terminus of p53 to inhibit p53 degradation by preventing MDM2 from interacting with p53. Moreover, ablation of p53 attenuated the antitumorigenic effects of LACTB overexpression in CRC. Collectively, our findings successfully demonstrate for the first time that LACTB is a novel epigenetic silenced tumor suppressor through modulating the stability of p53, supporting the pursuit of LACTB as a potential therapeutic target for CRC.

  20. Identification of Plagl1/Zac1 binding sites and target genes establishes its role in the regulation of extracellular matrix genes and the imprinted gene network.

    Science.gov (United States)

    Varrault, Annie; Dantec, Christelle; Le Digarcher, Anne; Chotard, Laëtitia; Bilanges, Benoit; Parrinello, Hugues; Dubois, Emeric; Rialle, Stéphanie; Severac, Dany; Bouschet, Tristan; Journot, Laurent

    2017-10-13

    PLAGL1/ZAC1 undergoes parental genomic imprinting, is paternally expressed, and is a member of the imprinted gene network (IGN). It encodes a zinc finger transcription factor with anti-proliferative activity and is a candidate tumor suppressor gene on 6q24 whose expression is frequently lost in various neoplasms. Conversely, gain of PLAGL1 function is responsible for transient neonatal diabetes mellitus, a rare genetic disease that results from defective pancreas development. In the present work, we showed that Plagl1 up-regulation was not associated with DNA damage-induced cell cycle arrest. It was rather associated with physiological cell cycle exit that occurred with contact inhibition, growth factor withdrawal, or cell differentiation. To gain insights into Plagl1 mechanism of action, we identified Plagl1 target genes by combining chromatin immunoprecipitation and genome-wide transcriptomics in transfected cell lines. Plagl1-elicited gene regulation correlated with multiple binding to the proximal promoter region through a GC-rich motif. Plagl1 target genes included numerous genes involved in signaling, cell adhesion, and extracellular matrix composition, including collagens. Plagl1 targets also included 22% of the 409 genes that make up the IGN. Altogether, this work identified Plagl1 as a transcription factor that coordinated the regulation of a subset of IGN genes and controlled extracellular matrix composition. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. Structural investigation of nucleophosmin interaction with the tumor suppressor Fbw7γ.

    Science.gov (United States)

    Di Matteo, A; Franceschini, M; Paiardini, A; Grottesi, A; Chiarella, S; Rocchio, S; Di Natale, C; Marasco, D; Vitagliano, L; Travaglini-Allocatelli, C; Federici, L

    2017-09-18

    Nucleophosmin (NPM1) is a multifunctional nucleolar protein implicated in ribogenesis, centrosome duplication, cell cycle control, regulation of DNA repair and apoptotic response to stress stimuli. The majority of these functions are played through the interactions with a variety of protein partners. NPM1 is frequently overexpressed in solid tumors of different histological origin. Furthermore NPM1 is the most frequently mutated protein in acute myeloid leukemia (AML) patients. Mutations map to the C-terminal domain and lead to the aberrant and stable localization of the protein in the cytoplasm of leukemic blasts. Among NPM1 protein partners, a pivotal role is played by the tumor suppressor Fbw7γ, an E3-ubiquitin ligase that degrades oncoproteins like c-MYC, cyclin E, Notch and c-jun. In AML with NPM1 mutations, Fbw7γ is degraded following its abnormal cytosolic delocalization by mutated NPM1. This mechanism also applies to other tumor suppressors and it has been suggested that it may play a key role in leukemogenesis. Here we analyse the interaction between NPM1 and Fbw7γ, by identifying the protein surfaces implicated in recognition and key aminoacids involved. Based on the results of computational methods, we propose a structural model for the interaction, which is substantiated by experimental findings on several site-directed mutants. We also extend the analysis to two other NPM1 partners (HIV Tat and CENP-W) and conclude that NPM1 uses the same molecular surface as a platform for recognizing different protein partners. We suggest that this region of NPM1 may be targeted for cancer treatment.

  2. MOXD2, a Gene Possibly Associated with Olfaction, Is Frequently Inactivated in Birds.

    Directory of Open Access Journals (Sweden)

    Chul Jun Goh

    Full Text Available Vertebrate MOXD2 encodes a monooxygenase DBH-like 2 protein that could be involved in neurotransmitter metabolism, potentially during olfactory transduction. Loss of MOXD2 in apes and whales has been proposed to be associated with evolution of olfaction in these clades. We analyzed 57 bird genomes to identify MOXD2 sequences and found frequent loss of MOXD2 in 38 birds. Among the 57 birds, 19 species appeared to have an intact MOXD2 that encoded a full-length protein; 32 birds had a gene with open reading frame-disrupting point mutations and/or exon deletions; and the remaining 6 species did not show any MOXD2 sequence, suggesting a whole-gene deletion. Notably, among 10 passerine birds examined, 9 species shared a common genomic deletion that spanned several exons, implying the gene loss occurred in a common ancestor of these birds. However, 2 closely related penguin species, each of which had an inactive MOXD2, did not share any mutation, suggesting an independent loss after their divergence. Distribution of the 38 birds without an intact MOXD2 in the bird phylogenetic tree clearly indicates that MOXD2 loss is widespread and independent in bird lineages. We propose that widespread MOXD2 loss in some bird lineages may be implicated in the evolution of olfactory perception in these birds.

  3. MOXD2, a Gene Possibly Associated with Olfaction, Is Frequently Inactivated in Birds.

    Science.gov (United States)

    Goh, Chul Jun; Choi, Dongjin; Park, Dong-Bin; Kim, Hyein; Hahn, Yoonsoo

    2016-01-01

    Vertebrate MOXD2 encodes a monooxygenase DBH-like 2 protein that could be involved in neurotransmitter metabolism, potentially during olfactory transduction. Loss of MOXD2 in apes and whales has been proposed to be associated with evolution of olfaction in these clades. We analyzed 57 bird genomes to identify MOXD2 sequences and found frequent loss of MOXD2 in 38 birds. Among the 57 birds, 19 species appeared to have an intact MOXD2 that encoded a full-length protein; 32 birds had a gene with open reading frame-disrupting point mutations and/or exon deletions; and the remaining 6 species did not show any MOXD2 sequence, suggesting a whole-gene deletion. Notably, among 10 passerine birds examined, 9 species shared a common genomic deletion that spanned several exons, implying the gene loss occurred in a common ancestor of these birds. However, 2 closely related penguin species, each of which had an inactive MOXD2, did not share any mutation, suggesting an independent loss after their divergence. Distribution of the 38 birds without an intact MOXD2 in the bird phylogenetic tree clearly indicates that MOXD2 loss is widespread and independent in bird lineages. We propose that widespread MOXD2 loss in some bird lineages may be implicated in the evolution of olfactory perception in these birds.

  4. Targeting myeloid-derived suppressor cells augments antitumor activity against lung cancer

    Directory of Open Access Journals (Sweden)

    Srivastava MK

    2012-10-01

    Full Text Available Minu K Srivastava,1,2 Li Zhu,1,2 Marni Harris-White,2 Min Huang,1–3 Maie St John,1,3 Jay M Lee,1,3 Ravi Salgia,4 Robert B Cameron,1,3,5 Robert Strieter,6 Steven Dubinett,1–3 Sherven Sharma1–31Department of Medicine, UCLA Lung Cancer Research Program, David Geffen School of Medicine at UCLA, Los Angeles, CA, 2Molecular Gene Medicine Laboratory, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 3Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, 4Department of Medicine, University of Chicago, Chicago, IL, 5Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 6Department of Medicine, University of Virginia, Charlottesville, VA, USAAbstract: Lung cancer evades host immune surveillance by dysregulating inflammation. Tumors and their surrounding stromata produce growth factors, cytokines, and chemokines that recruit, expand, and/or activate myeloid-derived suppressor cells (MDSCs. MDSCs regulate immune responses and are frequently found in malignancy. In this review the authors discuss tumor-MDSC interactions that suppress host antitumor activities and the authors' recent findings regarding MDSC depletion that led to improved therapeutic vaccination responses against lung cancer. Despite the identification of a repertoire of tumor antigens, hurdles persist for immune-based anticancer therapies. It is likely that combined therapies that address the multiple immune deficits in cancer patients will be required for effective therapy. MDSCs play a major role in the suppression of T-cell activation and they sustain tumor growth, proliferation, and metastases. Regulation of MDSC recruitment, differentiation or expansion, and inhibition of the MDSC suppressive function with pharmacologic agents will be useful in the control of cancer growth and progression. Pharmacologic agents that regulate MDSCs may be more effective when combined with

  5. The allele frequency of two single nucleotide polymorphisms in the von Hippel-Lindau (VHL) tumor suppressor gene in the Taiwanese population.

    Science.gov (United States)

    Wang, Wen-Chung; Chen, Hui-Ju; Shu, Wei-Pang; Tsai, Yi-Chang; Lai, Yen-Chein

    2011-10-01

    The von Hippel-Lindau (VHL) tumor suppressor gene located on chromosome 3p25-26 is implicated in VHL disease. Two informative single nucleotide polymorphisms are at positions 19 and 1149 on the nucleotide sequence from Gene Bank NM_000551. In this study we examined the allele frequencies at these two loci in the Taiwanese population and compared the results to those from European ethnic populations. The allele frequency was examined in 616 healthy individuals including 301 university students and 315 neonates. Both A/G polymorphisms were investigated using restriction fragment length polymorphism analysis created by restriction enzymes, BsaJ I and Acc I. Among these subjects, the allele frequencies at 19 SNP and 1149 SNP for variant G were 0.130 and 0.133, respectively. And these results were significant differences from those of the Caucasian populations. In addition, 90% of the tested subjects had identical genotypes at these two loci suggesting the existence of nonrandom association of alleles. We found that the G allele frequency at these two loci in the Taiwanese population is much lower than that in people from Western countries. This phenomenon may be attributed to ethnic effects. Copyright © 2011. Published by Elsevier B.V.

  6. Simultaneous down-regulation of tumor suppressor genes RBSP3/CTDSPL, NPRL2/G21 and RASSF1A in primary non-small cell lung cancer

    International Nuclear Information System (INIS)

    Senchenko, Vera N; Zabarovsky, Eugene R; Anedchenko, Ekaterina A; Kondratieva, Tatiana T; Krasnov, George S; Dmitriev, Alexei A; Zabarovska, Veronika I; Pavlova, Tatiana V; Kashuba, Vladimir I; Lerman, Michael I

    2010-01-01

    The short arm of human chromosome 3 is involved in the development of many cancers including lung cancer. Three bona fide lung cancer tumor suppressor genes namely RBSP3 (AP20 region),NPRL2 and RASSF1A (LUCA region) were identified in the 3p21.3 region. We have shown previously that homozygous deletions in AP20 and LUCA sub-regions often occurred in the same tumor (P < 10 -6 ). We estimated the quantity of RBSP3, NPRL2, RASSF1A, GAPDH, RPN1 mRNA and RBSP3 DNA copy number in 59 primary non-small cell lung cancers, including 41 squamous cell and 18 adenocarcinomas by real-time reverse transcription-polymerase chain reaction based on TaqMan technology and relative quantification. We evaluated the relationship between mRNA level and clinicopathologic characteristics in non-small cell lung cancer. A significant expression decrease (≥2) was found for all three genes early in tumor development: in 85% of cases for RBSP3; 73% for NPRL2 and 67% for RASSF1A (P < 0.001), more strongly pronounced in squamous cell than in adenocarcinomas. Strong suppression of both, NPRL2 and RBSP3 was seen in 100% of cases already at Stage I of squamous cell carcinomas. Deregulation of RASSF1A correlated with tumor progression of squamous cell (P = 0.196) and adenocarcinomas (P < 0.05). Most likely, genetic and epigenetic mechanisms might be responsible for transcriptional inactivation of RBSP3 in non-small cell lung cancers as promoter methylation of RBSP3 according to NotI microarrays data was detected in 80% of squamous cell and in 38% of adenocarcinomas. With NotI microarrays we tested how often LUCA (NPRL2, RASSF1A) and AP20 (RBSP3) regions were deleted or methylated in the same tumor sample and found that this occured in 39% of all studied samples (P < 0.05). Our data support the hypothesis that these TSG are involved in tumorigenesis of NSCLC. Both genetic and epigenetic mechanisms contribute to down-regulation of these three genes representing two tumor suppressor clusters in 3p21

  7. The induction of a tumor suppressor gene (p53) expression by low-dose radiation and its biological meaning

    International Nuclear Information System (INIS)

    Ohnishi, Takeo

    1997-01-01

    I report the induced accumulation of wild-type p53 protein of a tumor suppressor gene within 12 h in various organs of rats exposed to X-ray irradiation at low doses (10-50 cGy). The levels of p53 in some organs of irradiated rats were increased about 2- to 3-fold in comparison with the basal p53 levels in non-irradiated rats. Differences in the levels of p53 induction after low-dose X-ray irradiation were observed among the small intestine, bone marrow, brain, liver, adrenal gland, spleen, hypophysis and skin. In contrast, there was no obvious accumulation of p53 protein in the testis and ovary. Thus, the induction of cellular p.53 accumulation by low-dose X-ray irradiation in rats seems to be organ-specific. I consider that cell type, and interactions with other signal transduction pathways of the hormone system, immune system and nervous system may contribute to the variable induction of p53 by low-dose X-ray irradiation. I discussed the induction of p53 by radiation and its biological meaning from an aspect of the defense system for radiation-induced cancer. (author)

  8. Promoter Methylation Analysis of IDH Genes in Human Gliomas

    International Nuclear Information System (INIS)

    Flanagan, Simon; Lee, Maggie; Li, Cheryl C. Y.; Suter, Catherine M.; Buckland, Michael E.

    2012-01-01

    Mutations in isocitrate dehydrogenase (IDH)-1 or -2 are found in the majority of WHO grade II and III astrocytomas and oligodendrogliomas, and secondary glioblastomas. Almost all described mutations are heterozygous missense mutations affecting a conserved arginine residue in the substrate binding site of IDH1 (R132) or IDH2 (R172). But the exact mechanism of IDH mutations in neoplasia is not understood. It has been proposed that IDH mutations impart a “toxic gain-of-function” to the mutant protein, however a dominant-negative effect of mutant IDH has also been described, implying that IDH may function as a tumor suppressor gene. As most, if not all, tumor suppressor genes are inactivated by epigenetic silencing, in a wide variety of tumors, we asked if IDH1 or IDH2 carry the epigenetic signature of a tumor suppressor by assessing cytosine methylation at their promoters. Methylation was quantified in 68 human brain tumors, including both IDH-mutant and IDH wildtype, by bisulfite pyrosequencing. In all tumors examined, CpG methylation levels were less than 8%. Our data demonstrate that inactivation of IDH function through promoter hypermethylation is not common in human gliomas and other brain tumors. These findings do not support a tumor suppressor role for IDH genes in human gliomas.

  9. Induction of specific suppressor T cells in vitro

    International Nuclear Information System (INIS)

    Eardley, D.D.; Gershon, R.K.

    1976-01-01

    We describe conditions for generating sheep red blood cell-specific suppressor T cells in Mishell-Dutton cultures. The production of specific suppressor cells is favored by increasing antigen dose in the initial culture but can be produced by transferring more cells when lower doses of antigen are used. Transfer of small numbers of cells cultured with low doses of antigen leads to a specific helper effect. Transfer of large numbers of educated cells leads to nonspecific suppression. Suppression can be effected by the effluent cells from nylon wool columns which do not make detectable PFC. A fraction of these cells become resistant to treatment with anti-T cell sera and complement after culture. The suppressor cells are radiation sensitive and must be able to synthesize protein to suppress. They take 2 to 3 days of education to reach maximum suppressive efficiency and will not suppress cultures if added 2 to 3 days after culture initiation. Their production is favored by the absence of mercaptoethanol, suggesting that the observed suppression is not ''too much help.'' The ability to generate specific suppressor cells in vitro should be of great benefit in determining the factors that regulate their appearance in vivo

  10. Catalytic activity of matrix metalloproteinase-19 is essential for tumor suppressor and anti-angiogenic activities in nasopharyngeal carcinoma

    Czech Academy of Sciences Publication Activity Database

    Chan, K.C.; Ko, J.M.; Lung, H.L.; Sedláček, Radislav; Zhang, Z.F.; Luo, D.Z.; Feng, Z.B.; Chen, S.; Chen, H.; Chan, K.W.; Tsao, S.W.; Chua, D.T.; Zabarovsky, E.R.; Stanbridge, E.J.; Lung, M.L.

    2011-01-01

    Roč. 129, č. 8 (2011), s. 1826-1837 ISSN 0020-7136 Grant - others:Research Grants Council of the Hong Kong Special Administrative Region(CN) HKU661708M Institutional research plan: CEZ:AV0Z50520514 Keywords : MMP19 * nasopharyngeal carcinoma * tumor suppressor gene * angiogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.444, year: 2011

  11. Soluble suppressor supernatants elaborated by concanavalin A-activated human mononuclear cells. Characterization of a soluble suppressor of B cell immunoglobulin production

    International Nuclear Information System (INIS)

    Fleisher, T.A.; Greene, W.C.; Blaese, R.M.; Waldmann, T.A.

    1981-01-01

    Human peripheral blood mononuclear cells (PBMC) activated with the mitogenic lectin concanavalin A (Con A) elaborate a soluble immune suppressor supernatant (SISS) that contains at least 2 distinct suppressor factors. One of these, SISS-B, inhibits polyclonal B cell immunoglobulin production, whereas the other, SISS-T, suppresses T cell proliferation to both mitogens and antigens. The latter mediator is discussed in the companion paper. Characteristics of the human soluble suppressor of B cell immunoglobulin production (SISS-B) include: 1) inhibition by a noncytotoxic mechanism, 2) loss of activity in the presence of the monosaccharide L-rhamnose, 3) appearance within 8 to 16 hr after the addition of Con A, 4) elaboration by cells irradiated with 500 or 2000 rads, 5) production by highly purified T cells, 6) stability at pH 2.5 but instability at 56/sup o/C, and 7) m.w. of 60 to 80,000. These data indicate that after Con A activation, selected T cells not only become potent suppressor cells, but also generate a soluble saccharide-specific factor(s) that inhibits polyclonal immunoglobulin production by human B cells

  12. Infrared suppressor effect on T63 turboshaft engine performance

    Science.gov (United States)

    Bailey, E. E.; Civinskas, K. C.; Walker, C. L.

    1978-01-01

    Tests were conducted to determine if there are performance penalties associated with the installation of infrared (IR) suppressors on the T63-A-700 turboshaft engine. The testing was done in a sea-level, static test cell. The same engine (A-E402808 B) was run with the standard OH-58 aircraft exhaust stacks and with the ejector-type IR suppressors in order to make a valid comparison. Repeatability of the test results for the two configurations was verified by rerunning the conditions over a period of days. Test results showed no measurable difference in performance between the standard exhaust stacks and the IR suppressors.

  13. The role of UV induced lesions in skin carcinogenesis: an overview of oncogene and tumor suppressor gene modifications in xeroderma pigmentosum skin tumors

    International Nuclear Information System (INIS)

    Daya-Grosjean, Leela; Sarasin, Alain

    2005-01-01

    Xeroderma pigmentosum (XP), a rare hereditary syndrome, is characterized by a hypersensitivity to solar irradiation due to a defect in nucleotide excision repair resulting in a predisposition to squamous and basal cell carcinomas as well as malignant melanomas appearing at a very early age. The mutator phenotype of XP cells is evident by the higher levels of UV specific modifications found in key regulatory genes in XP skin tumors compared to those in the same tumor types from the normal population. Thus, XP provides a unique model for the study of unrepaired DNA lesions, mutations and skin carcinogenesis. The high level of ras oncogene activation, Ink4a-Arf and p53 tumor suppressor gene modifications as well as alterations of the different partners of the mitogenic sonic hedgehog signaling pathway (patched, smoothened and sonic hedgehog), characterized in XP skin tumors have clearly demonstrated the major role of the UV component of sunlight in the development of skin tumors. The majority of the mutations are C to T or tandem CC to TT UV signature transitions, occurring at bipyrimidine sequences, the specific targets of UV induced lesions. These characteristics are also found in the same genes modified in sporadic skin cancers but with lower frequencies confirming the validity of studying the XP model. The knowledge gained by studying XP tumors has given us a greater perception of the contribution of genetic predisposition to cancer as well as the consequences of the many alterations which modulate the activities of different genes affecting crucial pathways vital for maintaining cell homeostasis

  14. The role of UV induced lesions in skin carcinogenesis: an overview of oncogene and tumor suppressor gene modifications in xeroderma pigmentosum skin tumors

    Energy Technology Data Exchange (ETDEWEB)

    Daya-Grosjean, Leela [Laboratory of Genetic Instability and Cancer, UPR2169 CNRS, IFR 54, Institut Gustave Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)]. E-mail: daya@igr.fr; Sarasin, Alain [Laboratory of Genetic Instability and Cancer, UPR2169 CNRS, IFR 54, Institut Gustave Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)

    2005-04-01

    Xeroderma pigmentosum (XP), a rare hereditary syndrome, is characterized by a hypersensitivity to solar irradiation due to a defect in nucleotide excision repair resulting in a predisposition to squamous and basal cell carcinomas as well as malignant melanomas appearing at a very early age. The mutator phenotype of XP cells is evident by the higher levels of UV specific modifications found in key regulatory genes in XP skin tumors compared to those in the same tumor types from the normal population. Thus, XP provides a unique model for the study of unrepaired DNA lesions, mutations and skin carcinogenesis. The high level of ras oncogene activation, Ink4a-Arf and p53 tumor suppressor gene modifications as well as alterations of the different partners of the mitogenic sonic hedgehog signaling pathway (patched, smoothened and sonic hedgehog), characterized in XP skin tumors have clearly demonstrated the major role of the UV component of sunlight in the development of skin tumors. The majority of the mutations are C to T or tandem CC to TT UV signature transitions, occurring at bipyrimidine sequences, the specific targets of UV induced lesions. These characteristics are also found in the same genes modified in sporadic skin cancers but with lower frequencies confirming the validity of studying the XP model. The knowledge gained by studying XP tumors has given us a greater perception of the contribution of genetic predisposition to cancer as well as the consequences of the many alterations which modulate the activities of different genes affecting crucial pathways vital for maintaining cell homeostasis.

  15. MicroRNA-148b is frequently down-regulated in gastric cancer and acts as a tumor suppressor by inhibiting cell proliferation

    Directory of Open Access Journals (Sweden)

    Jiang Li

    2011-01-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are involved in cancer development and progression, acting as tumor suppressors or oncogenes. Our previous studies have revealed that miR-148a and miR-152 are significantly down-regulated in gastrointestinal cancers. Interestingly, miR-148b has the same "seed sequences" as miR-148a and miR-152. Although aberrant expression of miR-148b has been observed in several types of cancer, its pathophysiologic role and relevance to tumorigenesis are still largely unknown. The purpose of this study was to elucidate the molecular mechanisms by which miR-148b acts as a tumor suppressor in gastric cancer. Results We showed significant down-regulation of miR-148b in 106 gastric cancer tissues and four gastric cancer cell lines, compared with their non-tumor counterparts by real-time RT-PCR. In situ hybridization of ten cases confirmed an overt decrease in the level of miR-148b in gastric cancer tissues. Moreover, the expression of miR-148b was demonstrated to be associated with tumor size (P = 0.027 by a Mann-Whitney U test. We also found that miR-148b could inhibit cell proliferation in vitro by MTT assay, growth curves and an anchorage-independent growth assay in MGC-803, SGC-7901, BGC-823 and AGS cells. An experiment in nude mice revealed that miR-148b could suppress tumorigenicity in vivo. Using a luciferase activity assay and western blot, CCKBR was identified as a target of miR-148b in cells. Moreover, an obvious inverse correlation was observed between the expression of CCKBR protein and miR-148b in 49 pairs of tissues (P = 0.002, Spearman's correlation. Conclusions These findings provide important evidence that miR-148b targets CCKBR and is significant in suppressing gastric cancer cell growth. Maybe miR-148b would become a potential biomarker and therapeutic target against gastric cancer.

  16. DR-Integrator: a new analytic tool for integrating DNA copy number and gene expression data.

    Science.gov (United States)

    Salari, Keyan; Tibshirani, Robert; Pollack, Jonathan R

    2010-02-01

    DNA copy number alterations (CNA) frequently underlie gene expression changes by increasing or decreasing gene dosage. However, only a subset of genes with altered dosage exhibit concordant changes in gene expression. This subset is likely to be enriched for oncogenes and tumor suppressor genes, and can be identified by integrating these two layers of genome-scale data. We introduce DNA/RNA-Integrator (DR-Integrator), a statistical software tool to perform integrative analyses on paired DNA copy number and gene expression data. DR-Integrator identifies genes with significant correlations between DNA copy number and gene expression, and implements a supervised analysis that captures genes with significant alterations in both DNA copy number and gene expression between two sample classes. DR-Integrator is freely available for non-commercial use from the Pollack Lab at http://pollacklab.stanford.edu/ and can be downloaded as a plug-in application to Microsoft Excel and as a package for the R statistical computing environment. The R package is available under the name 'DRI' at http://cran.r-project.org/. An example analysis using DR-Integrator is included as supplemental material. Supplementary data are available at Bioinformatics online.

  17. Restoration of tumor suppressor miR-34 inhibits human p53-mutant gastric cancer tumorspheres

    International Nuclear Information System (INIS)

    Ji, Qing; Hao, Xinbao; Meng, Yang; Zhang, Min; DeSano, Jeffrey; Fan, Daiming; Xu, Liang

    2008-01-01

    MicroRNAs (miRNAs), some of which function as oncogenes or tumor suppressor genes, are involved in carcinogenesis via regulating cell proliferation and/or cell death. MicroRNA miR-34 was recently found to be a direct target of p53, functioning downstream of the p53 pathway as a tumor suppressor. miR-34 targets Notch, HMGA2, and Bcl-2, genes involved in the self-renewal and survival of cancer stem cells. The role of miR-34 in gastric cancer has not been reported previously. In this study, we examined the effects of miR-34 restoration on p53-mutant human gastric cancer cells and potential target gene expression. Human gastric cancer cells were transfected with miR-34 mimics or infected with the lentiviral miR-34-MIF expression system, and validated by miR-34 reporter assay using Bcl-2 3'UTR reporter. Potential target gene expression was assessed by Western blot for proteins, and by quantitative real-time RT-PCR for mRNAs. The effects of miR-34 restoration were assessed by cell growth assay, cell cycle analysis, caspase-3 activation, and cytotoxicity assay, as well as by tumorsphere formation and growth. Human gastric cancer Kato III cells with miR-34 restoration reduced the expression of target genes Bcl-2, Notch, and HMGA2. Bcl-2 3'UTR reporter assay showed that the transfected miR-34s were functional and confirmed that Bcl-2 is a direct target of miR-34. Restoration of miR-34 chemosensitized Kato III cells with a high level of Bcl-2, but not MKN-45 cells with a low level of Bcl-2. miR-34 impaired cell growth, accumulated the cells in G1 phase, increased caspase-3 activation, and, more significantly, inhibited tumorsphere formation and growth. Our results demonstrate that in p53-deficient human gastric cancer cells, restoration of functional miR-34 inhibits cell growth and induces chemosensitization and apoptosis, indicating that miR-34 may restore p53 function. Restoration of miR-34 inhibits tumorsphere formation and growth, which is reported to be

  18. Tumor suppressor gene mutation in a patient with a history of hyperparathyroidism-jaw tumor syndrome and healed generalized osteitis fibrosa cystica: a case report and genetic pathophysiology review.

    Science.gov (United States)

    Parfitt, Joshua; Harris, Malcolm; Wright, John M; Kalamchi, Sabah

    2015-01-01

    Hyperparathyroidism-jaw tumor (HPT-JT) was first observed by Jackson in 1958 in a family who exhibited hyperparathyroidism and recurrent pancreatitis. The author noticed the presence of jaw tumors in the affected family and reported them as fibrous dysplasia. However, it was not until 1990 that a familial variety of hyperparathyroidism with fibro-osseous jaw tumors was recognized as HPT-JT syndrome and reported as a clinically and genetically distinct syndrome. Hyperparathyroidism generally arises from glandular hyperplasia or parathyroid adenomas, with only about 1% of cases resulting from parathyroid carcinoma. However, parathyroid carcinoma develops in about 15% of HPT-JT patients. The true incidence of HPT-JT is unknown, although the prevalence of about 100 published cases suggests its rarity. Twenty percent of HPT-JT cases have renal hamartomas or tumors, and female patients with HPT-JT have been reported to have carcinoma of the uterus. This syndrome appears to arise from a variety of mutations that deactivate the tumor suppressor gene CDC73 (also known as HRPT2) and its production of the tumor suppressor protein parafibromin. Functional parafibromin has 531 amino acids, and mutations result in a short nonfunctional protein. CDC73 disorders exhibit dominant germline gene behavior, with varying degrees of penetration. In most cases an affected person has 1 parent with the condition, which raises the need for family investigation and genetic counseling. We report a case of HPT-JT syndrome in a male patient who presented to the local community hospital 6 years previously with a history of back pain. Investigations showed elevated serum parathyroid hormone and calcium levels, and a technetium 99m sestamibi parathyroid scan showed increased activity at the site of the lower left gland that proved to be a substernal parathyroid carcinoma. The patient's parathyroid hormone level dropped from 126 to 97 pg/mL at 5 minutes and was 65 pg/mL at 10 minutes after excision

  19. The Neurofibromatosis 2 Tumor Suppressor Gene Product, Merlin, Regulates Human Meningioma Cell Growth by Signaling through YAP

    Directory of Open Access Journals (Sweden)

    Katherine Striedinger

    2008-11-01

    Full Text Available Neurofibromatosis type 2 (NF2 is an autosomal dominant disorder characterized by the occurrence of schwannomas and meningiomas. Several studies have examined the ability of the NF2 gene product, merlin, to function as a tumor suppressor in diverse cell types; however, little is known about merlin growth regulation in meningiomas. In Drosophila, merlin controls cell proliferation and apoptosis by signaling through the Hippo pathway to inhibit the function of the transcriptional coactivator Yorkie. The Hippo pathway is conserved in mammals. On the basis of these observations, we developed human meningioma cell lines matched for merlin expression to evaluate merlin growth regulation and investigate the relationship between NF2 status and Yes-associated protein (YAP, the mammalian homolog of Yorkie. NF2 loss in meningioma cells was associated with loss of contact-dependent growth inhibition, enhanced anchorage-independent growth and increased cell proliferation due to increased S-phase entry. In addition, merlin loss in both meningioma cell lines and primary tumors resulted in increased YAP expression and nuclear localization. Finally, siRNA-mediated reduction of YAP in NF2-deficient meningioma cells rescued the effects of merlin loss on cell proliferation and S-phase entry. Collectively, these results represent the first demonstration that merlin regulates cell growth in human cancer cells by suppressing YAP.

  20. The transformation suppressor gene Reck is required for postaxial patterning in mouse forelimbs

    Directory of Open Access Journals (Sweden)

    Mako Yamamoto

    2012-03-01

    The membrane-anchored metalloproteinase-regulator RECK has been characterized as a tumor suppressor. Here we report that mice with reduced Reck-expression show limb abnormalities including right-dominant, forelimb-specific defects in postaxial skeletal elements. The forelimb buds of low-Reck mutants have an altered dorsal ectoderm with reduced Wnt7a and Igf2 expression, and hypotrophy in two signaling centers (i.e., ZPA and AER that are essential for limb outgrowth and patterning. Reck is abundantly expressed in the anterior mesenchyme in normal limb buds; mesenchyme-specific Reck inactivation recapitulates the low-Reck phenotype; and some teratogens downregulate Reck in mesenchymal cells. Our findings illustrate a role for Reck in the mesenchymal-epithelial interactions essential for mammalian development.

  1. Identification of Two Candidate Tumor Suppressor Genes on Chromosome 17p13.3: Assessment of Their Roles in Breast and Ovarian Carcinogenesis

    National Research Council Canada - National Science Library

    Godwin, Andrew

    1998-01-01

    .... To date, we have found that: (1) OVCA2 is a new gene residing in a chromosomal region which is frequently lost in breast, brain, colon, ovarian tumors, acute myeloid leukemia and myelodysplastic syndromes, (2...

  2. An evolutionary rearrangement of the Xp11.3-11.23 region in 3p21.3, a region frequently deleted in a variety of cancers

    NARCIS (Netherlands)

    Timmer, T; Terpstra, P; van den Berg, Anke; Veldhuis, PMJF; Ter Elst, A; van der Veen, AY; Kok, K; Naylor, SL; Buys, CHCM

    1999-01-01

    In searching for a tumor suppressor gene in the 3p21.3 region, we isolated two genes, RBM5 and RBM6. Sequence analysis indicated that these genes share similarity. RBM5 and-to a lesser extent-RBM6 also have similarity to DXS8237E at Xp11.3-11.23, which maps less than 20 kb upstream of UBE1. A

  3. Photoreactivation of conversion and de novo suppressor mutation in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Bockrath, R C; Plamer, J E [Indiana Univ., Indianapolis (USA). Dept. of Microbiology

    1977-04-01

    Studies of mutagenesis and photoreactivation in various E.coli strains have shown that conversion mutation of a mutant containing an amber suppressor to one containing an ochre suppressor is sensitive to photoreactivation. Direct photoreactivation by photoreactivating light (PRL) after uv mutagenesis reduced mutation frequencies by a factor of about 2 for each minute of exposure during the first 5 to 8 min of exposure for cells with normal repair capacity. Conversion and potential de novo suppressor mutations were about equally sensitive. For conversion, the sensitivities to PRL were identical in the repair-normal and excisions-repair-deficient strains. For de novo suppressor mutation, the rate of mutation frequency reduction by PRL in the repair-deficient strain was about one-half that in the other strains. The results suggest that ultraviolet radiation produces both de novo suppressor mutation and conversion at the sup(E,B) locus by photoreversible pyrimidine dimers in the DNA. The causative dimers could be Thy()Cyt dimers in the transcribed strand or the non-transcribed strand, respectively.

  4. Less frequently mutated genes in colorectal cancer: evidences from next-generation sequencing of 653 routine cases.

    Science.gov (United States)

    Malapelle, Umberto; Pisapia, Pasquale; Sgariglia, Roberta; Vigliar, Elena; Biglietto, Maria; Carlomagno, Chiara; Giuffrè, Giuseppe; Bellevicine, Claudio; Troncone, Giancarlo

    2016-09-01

    The incidence of RAS/RAF/PI3KA and TP53 gene mutations in colorectal cancer (CRC) is well established. Less information, however, is available on other components of the CRC genomic landscape, which are potential CRC prognostic/predictive markers. Following a previous validation study, ion-semiconductor next-generation sequencing (NGS) was employed to process 653 routine CRC samples by a multiplex PCR targeting 91 hotspot regions in 22 CRC significant genes. A total of 796 somatic mutations in 499 (76.4%) tumours were detected. Besides RAS/RAF/PI3KA and TP53, other 12 genes showed at least one mutation including FBXW7 (6%), PTEN (2.8%), SMAD4 (2.1%), EGFR (1.2%), CTNNB1 (1.1%), AKT1 (0.9%), STK11 (0.8%), ERBB2 (0.6%), ERBB4 (0.6%), ALK (0.2%), MAP2K1 (0.2%) and NOTCH1 (0.2%). In a routine diagnostic setting, NGS had the potential to generate robust and comprehensive genetic information also including less frequently mutated genes potentially relevant for prognostic assessments or for actionable treatments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. Genistein up-regulates tumor suppressor microRNA-574-3p in prostate cancer.

    Directory of Open Access Journals (Sweden)

    Takeshi Chiyomaru

    Full Text Available Genistein has been shown to inhibit cancers both in vitro and in vivo, by altering the expression of several microRNAs (miRNAs. In this study, we focused on tumor suppressor miRNAs regulated by genistein and investigated their function in prostate cancer (PCa and target pathways. Using miRNA microarray analysis and real-time RT-PCR we observed that miR-574-3p was significantly up-regulated in PCa cells treated with genistein compared with vehicle control. The expression of miR-574-3p was significantly lower in PCa cell lines and clinical PCa tissues compared with normal prostate cells (RWPE-1 and adjacent normal tissues. Low expression level of miR-574-3p was correlated with advanced tumor stage and higher Gleason score in PCa specimens. Re-expression of miR-574-3p in PCa cells significantly inhibited cell proliferation, migration and invasion in vitro and in vivo. miR-574-3p restoration induced apoptosis through reducing Bcl-xL and activating caspase-9 and caspase-3. Using GeneCodis software analysis, several pathways affected by miR-574-3p were identified, such as 'Pathways in cancer', 'Jak-STAT signaling pathway', and 'Wnt signaling pathway'. Luciferase reporter assays demonstrated that miR-574-3p directly binds to the 3' UTR of several target genes (such as RAC1, EGFR and EP300 that are components of 'Pathways in cancer'. Quantitative real-time PCR and Western analysis showed that the mRNA and protein expression levels of the three target genes in PCa cells were markedly down-regulated with miR-574-3p. Loss-of-function studies demonstrated that the three target genes significantly affect cell proliferation, migration and invasion in PCa cell lines. Our results show that genistein up-regulates tumor suppressor miR-574-3p expression targeting several cell signaling pathways. These findings enhance understanding of how genistein regulates with miRNA in PCa.

  6. Frequent promoter hypermethylation of RASSF1A and CASP8 in neuroblastoma

    International Nuclear Information System (INIS)

    Lázcoz, Paula; Muñoz, Jorge; Nistal, Manuel; Pestaña, Ángel; Encío, Ignacio; Castresana, Javier S

    2006-01-01

    Epigenetic alterations and loss of heterozygosity are mechanisms of tumor suppressor gene inactivation. A new carcinogenic pathway, targeting the RAS effectors has recently been documented. RASSF1A, on 3p21.3, and NORE1A, on 1q32.1, are among the most important, representative RAS effectors. We screened the 3p21 locus for the loss of heterozygosity and the hypermethylation status of RASSF1A, NORE1A and BLU (the latter located at 3p21.3) in 41 neuroblastic tumors. The statistical relationship of these data was correlated with CASP8 hypermethylation. The expression levels of these genes, in cell lines, were analyzed by RT-PCR. Loss of heterozygosity and microsatellite instability at 3p21 were detected in 14% of the analyzed tumors. Methylation was different for tumors and cell lines (tumors: 83% in RASSF1A, 3% in NORE1A, 8% in BLU and 60% in CASP8; cell lines: 100% in RASSF1A, 50% in NORE1A, 66% in BLU and 92% in CASP8). In cell lines, a correlation with lack of expression was evident for RASSF1A, but less clear for NORE1A, BLU and CASP8. We could only demonstrate a statistically significant association between hypermethylation of RASSF1A and hypermethylation of CASP8, while no association with MYCN amplification, 1p deletion, and/or aggressive histological pattern of the tumor was demonstrated. 1) LOH at 3p21 appears in a small percentage of neuroblastomas, indicating that a candidate tumor suppressor gene of neuroblastic tumors is not located in this region. 2) Promoter hypermethylation of RASSF1A and CASP8 occurs at a high frequency in neuroblastomas

  7. The retinoblastoma gene is frequently altered leading to loss of expression in primary breast tumours.

    Science.gov (United States)

    Varley, J M; Armour, J; Swallow, J E; Jeffreys, A J; Ponder, B A; T'Ang, A; Fung, Y K; Brammar, W J; Walker, R A

    1989-06-01

    We have analysed the organisation of the retinoblastoma (RB1) gene in 77 primary breast carcinomas, in metastatic tissue derived from 16 of those primary tumours, and in a variety of benign breast lesions. Expression of RB1 was also assessed in most samples by immunohistochemical detection of the RB1 protein in tissue sections. Structural abnormalities to RB1 were detected in DNA from 15/77 (19%) of primary breast carcinomas examined. Where DNA was available from metastatic tissue derived from such primary tumours, the same aberration could be detected. No alterations were seen in benign breast lesions. 16/56 (29%) of tumours examined for expression by immunohistochemical methods showed a proportion of tumour cells to be completely negative for the RB1 protein. All tumours in which a structural alteration to RB1 was detected had a proportion of negative cells, except for one case where all cells were positive. Several primary tumour samples were identified where there was no detectable structural change to the gene, but there was loss of expression in some tumour cells. The data presented here demonstrate that changes to the RB1 gene leading to loss of expression of both alleles are frequent in primary human breast tumours.

  8. In vitro X-ray irradiation of human peripheral blood T lymphocytes enhances suppressor function

    International Nuclear Information System (INIS)

    Ogawa, H.; Tsunematsu, T.

    1983-01-01

    The effect of in vitro X-ray irradiation on human peripheral blood T lymphocytes was studied with regard to their suppressor activity related to the concanavalin A (Con A)-induced suppressor system. To generate suppressor T lymphocytes, purified human T lymphocytes were incubated for 3 days in the first culture, with or without Con A. These lymphocytes were irradiated with various doses of X-ray before, mid or after the culture. After doing a second culture for 6 days, the suppressive influence of these cells on T lymphocyte proliferation rates stimulated with allogeneic mononuclear cells, and B lymphocyte proliferation rates stimulated with pokeweed mitogen was measured. Irradiation of cultures to which Con A had not been added induced much the same level of suppressor activity as seen in the cultures with Con A. The suppressor activity gradually increased with time from the irradiation to the suppressor cell assay. Suppressor T lymphocytes were resistant to X-ray irradiation and independent of DNA synthesis. However, irradiation-induced enhancement was minimal in cultures incubated with con A, regardless of the irradiation time. (author)

  9. Regulatory role for the memory B cell as suppressor-inducer of feedback control

    International Nuclear Information System (INIS)

    Kennedy, M.W.; Thomas, D.B.

    1983-01-01

    A regulatory role is proposed for the antigen-responsive B cell, as suppressor-inducer of feedback control during the secondary response in vivo. In a double adoptive transfer of memory cells primed to a thymus-dependent antigen from one irradiated host to another, antigen-specific suppressors are generated after a critical time in the primary recipient, able to entirely ablate a secondary anti-hapten response. Positive cell selection in the fluorescence-activated cell sorter confirmed that suppression was mediated by an Lyt-2+ T cell; however, positively selected B cells were also inhibitory and able to induce suppressors in a carrier-specific manner: B hapten induced suppressors in a carrier-primed population, and B carrier induced suppressors in a hapten-carrier population. At the peak of the antibody response in the primary host, memory B cells and their progeny were unable to differentiate further to plasma cells due to their intrinsic suppressor-inducer activity, but this autoregulatory circuit could be severed by adoptive transfer to carrier-primed, X-irradiated recipients

  10. Suppressor Analysis of the Fusogenic Lambda Spanins.

    Science.gov (United States)

    Cahill, Jesse; Rajaure, Manoj; Holt, Ashley; Moreland, Russell; O'Leary, Chandler; Kulkarni, Aneesha; Sloan, Jordan; Young, Ry

    2017-07-15

    The final step of lysis in phage λ infections of Escherichia coli is mediated by the spanins Rz and Rz1. These proteins form a complex that bridges the cell envelope and that has been proposed to cause fusion of the inner and outer membranes. Accordingly, mutations that block spanin function are found within coiled-coil domains and the proline-rich region, motifs essential in other fusion systems. To gain insight into spanin function, pseudorevertant alleles that restored plaque formation for lysis-defective mutants of Rz and Rz1 were selected. Most second-site suppressors clustered within a coiled-coil domain of Rz near the outer leaflet of the cytoplasmic membrane and were not allele specific. Suppressors largely encoded polar insertions within the hydrophobic core of the coiled-coil interface. Such suppressor changes resulted in decreased proteolytic stability of the Rz double mutants in vivo Unlike the wild type, in which lysis occurs while the cells retain a rod shape, revertant alleles with second-site suppressor mutations supported lysis events that were preceded by spherical cell formation. This suggests that destabilization of the membrane-proximal coiled coil restores function for defective spanin alleles by increasing the conformational freedom of the complex at the cost of its normal, all-or-nothing functionality. IMPORTANCE Caudovirales encode cell envelope-spanning proteins called spanins, which are thought to fuse the inner and outer membranes during phage lysis. Recent genetic analysis identified the functional domains of the lambda spanins, which are similar to class I viral fusion proteins. While the pre- and postfusion structures of model fusion systems have been well characterized, the intermediate structure(s) formed during the fusion reaction remains elusive. Genetic analysis would be expected to identify functional connections between intermediates. Since most membrane fusion systems are not genetically tractable, only few such

  11. Insight into the tumor suppressor function of CBP through the viral oncoprotein tax.

    Science.gov (United States)

    Van Orden, K; Nyborg, J K

    2000-01-01

    CREB binding protein (CBP) is a cellular coactivator protein that regulates essentially all known pathways of gene expression. The transcriptional coactivator properties of CBP are utilized by at least 25 different transcription factors representing nearly all known classes of DNA binding proteins. Once bound to their target genes, these transcription factors are believed to tether CBP to the promoter, leading to activated transcription. CBP functions to stimulate transcription through direct recruitment of the general transcription machinery as well as acetylation of both histone and transcription factor substrates. Recent observations indicate that a critical dosage of CBP is required for normal development and tumor suppression, and that perturbations in CBP concentrations may disrupt cellular homeostasis. Furthermore, there is accumulating evidence that CBP deregulation plays a direct role in hematopoietic malignancies. However, the molecular events linking CBP deregulation and malignant transformation are unclear. Further insight into the function of CBP, and its role as a tumor suppressor, can be gained through recent studies of the human T-cell leukemia virus, type I (HTLV-I) Tax oncoprotein. Tax is known to utilize CBP to stimulate transcription from the viral promoter. However, recent data suggest that as a consequence of the Tax-CBP interaction, many cellular transcription factor pathways may be deregulated. Tax disruption of CBP function may play a key role in transformation of the HTLV-I-infected cell. Thus, Tax derailment of CBP may lend important information about the tumor suppressor properties of CBP and serve as a model for the role of CBP in hematopoietic malignancies.

  12. The role of baculovirus apoptotic suppressors in AcMNPV-mediated translation arrest in Ld652Y cells

    International Nuclear Information System (INIS)

    Thiem, Suzanne M.; Chejanovsky, Nor

    2004-01-01

    Infecting the insect cell line IPLB-Ld652Y with the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV) results in global translation arrest, which correlates with the presence of the AcMNPV apoptotic suppressor, p35. In this study, we investigated the role of apoptotic suppression on AcMNPV-induced translation arrest. Infecting cells with AcMNPV bearing nonfunctional mutant p35 did not result in global translation arrest. In contrast, global translation arrest was observed in cells infected with AcMNPV in which p35 was replaced with Opiap, Cpiap, or p49, baculovirus apoptotic suppressors that block apoptosis by different mechanisms than p35. These results indicated that suppressing apoptosis triggered translation arrest in AcMNPV-infected Ld652Y cells. Experiments using the DNA synthesis inhibitor aphidicolin and temperature shift experiments, using the AcMNPV replication mutants ts8 and ts8Δp35, indicated that translation arrest initiated during the early phase of infection, but events during the late phase were required for global translation arrest. Peptide caspase inhibitors could not substitute for baculovirus apoptotic suppressors to induce translation arrest in Ld652Y cells infected with a p35-null virus. However, if the p35-null-AcMNPV also carried hrf-1, a novel baculovirus host range gene, progeny virus was produced and treatment with peptide caspase inhibitors enhanced translation of a late viral gene transcript. Together, these results indicate that translation arrest in AcMNPV-infected Ld652Y cells is due to the anti-apoptotic function of p35, but suggests that rather than simply preventing caspase activation, its activity enhances signaling to a separate translation arrest pathway, possibly by stimulating the late stages of the baculovirus infection cycle

  13. Determination of Heritage SSME Pogo Suppressor Resistance and Inertance from Waterflow Pulse Testing

    Science.gov (United States)

    McDougal, Chris; Eberhart, Chad; Lee, Erik

    2016-01-01

    Waterflow tests of a heritage Space Shuttle Main Engine pogo suppressor were performed to experimentally quantify the resistance and inertance provided by the suppressor. Measurements of dynamic pressure and flow rate in response to pulsing flow were made throughout the test loop. A unique system identification methodology combined all sensor measurements with a one-dimensional perturbational flow model of the complete water flow loop to spatially translate physical measurements to the device under test. Multiple techniques were then employed to extract the effective resistance and inertance for the pogo suppressor. Parameters such as steady flow rate, perturbational flow rate magnitude, and pulse frequency were investigated to assess their influence on the behavior of the pogo suppressor dynamic response. These results support validation of the RS-25 pogo suppressor performance for use on the Space Launch System Core Stage.

  14. Candidate driver genes in microsatellite-unstable colorectal cancer

    DEFF Research Database (Denmark)

    Alhopuro, Pia; Sammalkorpi, Heli; Niittymäki, Iina

    2012-01-01

    Defects in the mismatch repair system lead to microsatellite instability (MSI), a feature observed in ∼ 15% of all colorectal cancers (CRCs). Microsatellite mutations that drive tumourigenesis, typically inactivation of tumour suppressors, are selected for and are frequently detected in MSI cancers...

  15. Changes in helper and suppressor T lymphocytes following radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Newman, G.H.; Rees, G.J.G.; Jones, R.S.J.; Grove, E.A.; Preece, A.W.

    1987-01-01

    Changes in total lymphocyte, T lymphocyte, T helper and T suppressor lymphocyte numbers were studied in 22 patients with breast cancer before and after radiotherapy. T lymphocyte subsets were measured using monoclonal antibodies and fluorescence microscopy. After treatment the total lymphocyte count fell significantly and was still reduced 9 months later, but the proportion of cells labelled as T lymphocytes was unchanged during this period. The helper-suppressor ratio, which was within the normal range before radiotherapy, was significantly reduced at 3 months and 9 months after. Following treatment both T helper and T suppressor cell numbers were significantly reduced. T helper cell numbers remained reduced throughout the study period but T suppressor cell numbers showed a recovery to normal values 9 months after radiotherapy. (author)

  16. LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Cai

    2017-07-01

    Full Text Available Myeloid-derived suppressor cells (MDSCs are expanded in tumor microenvironments, including that of Epstein-Barr virus (EBV-associated nasopharyngeal carcinoma (NPC. The link between MDSC expansion and EBV infection in NPC is unclear. Here, we show that EBV latent membrane protein 1 (LMP1 promotes MDSC expansion in the tumor microenvironment by promoting extra-mitochondrial glycolysis in malignant cells, which is a scenario for immune escape initially suggested by the frequent, concomitant detection of abundant LMP1, glucose transporter 1 (GLUT1 and CD33+ MDSCs in tumor sections. The full process has been reconstituted in vitro. LMP1 promotes the expression of multiple glycolytic genes, including GLUT1. This metabolic reprogramming results in increased expression of the Nod-like receptor family protein 3 (NLRP3 inflammasome, COX-2 and P-p65 and, consequently, increased production of IL-1β, IL-6 and GM-CSF. Finally, these changes in the environment of malignant cells result in enhanced NPC-derived MDSC induction. One key step is the physical interaction of LMP1 with GLUT1 to stabilize the GLUT1 protein by blocking its K48-ubiquitination and p62-dependent autolysosomal degradation. This work indicates that LMP1-mediated glycolysis regulates IL-1β, IL-6 and GM-CSF production through the NLRP3 inflammasome, COX-2 and P-p65 signaling pathways to enhance tumor-associated MDSC expansion, which leads to tumor immunosuppression in NPC.

  17. INHIBITION OF THE DNA-BINDING ACTIVITY OF DROSOPHILA SUPPRESSOR OF HAIRLESS AND OF ITS HUMAN HOMOLOG, KBF2/RBP-J-KAPPA, BY DIRECT PROTEIN-PROTEIN INTERACTION WITH DROSOPHILA HAIRLESS

    NARCIS (Netherlands)

    BROU, C; LOGEAT, F; LECOURTOIS, M; VANDEKERCKHOVE, Joël; KOURILSKY, P; SCHWEISGUTH, F; ISRAEL, A

    1994-01-01

    We have purified the sequence-specific DNA-binding protein KBF2 and cloned the corresponding cDNA, which is derived from the previously described RBP-J kappa gene, the human homolog of the Drosophila Suppressor of Hairless [Su(H)] gene. Deletion studies of the RBP-J kappa and Su(H) proteins allowed

  18. Influence of tumour suppressor gene (TP53, BRCA1 and BRCA2) polymorphisms on polycystic ovary syndrome in South Indian women.

    Science.gov (United States)

    Siddamalla, Swapna; Reddy, Tumu Venkat; Govatati, Suresh; Guruvaiah, Praveen; Deenadayal, Mamata; Shivaji, Sisinthy; Bhanoori, Manjula

    2018-05-24

    Polycystic Ovary Syndrome (PCOS) is a heterogeneous multifactorial endocrine metabolic disorder. In addition to hyperandrogenism, acne, hirsutism, obesity, oligoanovulation and infertility, insulin resistance is also a common feature in women of PCOS. Tumor suppressor genes (TSGs) perform essential function in the maintenance of genomic stability and regulatory pathways influencing the activity of several replication and transcription factors. The main aim of this study was to investigate the association of Single Nucleotide Polymorphisms of TP53, BRCA1and BRCA2 genes with the susceptibility to PCOS in South Indian women. Present study investigated association between TP53 gene (rs1042522 G/C), BRCA1 (rs71361504 -/GTT, rs3092986 T/C) and BRCA2 (rs206118 A/G) and, SNPs and PCOS risk. Genotyping of TSGs was carried out on DNA from PCOS patients (n = 110) and controls (n = 130) of South Indian origin by polymerase chain reaction (PCR) and confirmed by sequencing analysis. The genotype frequency and allele distributions of cases and controls were analyzed using Fisher's exact test. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pair wise linkage disequilibrium (LD) were assessed by Haploview Software. Significant increase in frequencies ofTP53 (rs1042522 G/C), BRCA1 (rs71361504 -/GTT, rs3092986 T/C) genotypes and alleles in patients compared to controls. In addition, the frequency of the C/T (P = 0.002) and A/C (P = 0.012) haplotype was also significantly elevated in patients. But BRCA2 (rs206118 A/G) did not show significant association with PCOS. The TP53 and BRCA1 may constitute an inheritable risk factor for PCOS in South Indian women. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Visualization of plant viral suppressor silencing activity in intact leaf lamina by quantitative fluorescent imaging

    Directory of Open Access Journals (Sweden)

    Francis Kevin P

    2011-08-01

    Full Text Available Abstract Background Transient expression of proteins in plants has become a favoured method over the production of stably transformed plants because, in addition to enabling high protein yields, it is both fast and easy to apply. An enhancement of transient protein expression can be achieved by plant virus-encoded RNA silencing suppressor proteins. Since viral suppressor proteins differ in their efficiency to enhance transient protein expression in plants, we developed a whole-leaf green fluorescent protein (GFP-based imaging assay to quantitatively assess suppressor protein activity. Results In a transient GFP-expression assay using wild-type and GFP-transgenic N. benthamiana, addition of the plant viral suppressors Beet mild yellowing virus (BMYV-IPP P0 or Plum pox virus (PPV HC-Pro was shown to increase fluorescent protein expression 3-4-fold, 7 days post inoculation (dpi when compared to control plants. In contrast, in agroinfiltrated patches without suppressor activity, near complete silencing of the GFP transgene was observed in the transgenic N. benthamiana at 21 dpi. Both co-infiltrated suppressors significantly enhanced GFP expression over time, with HC-Pro co-infiltrations leading to higher short term GFP fluorescence (at 7 dpi and P0 giving higher long term GFP fluorescence (at 21 dpi. Additionally, in contrast to HC-Pro co-infiltrations, an area of complete GFP silencing was observed at the edge of P0 co-infiltrated areas. Conclusions Fluorescence imaging of whole intact leaves proved to be an easy and effective method for spatially and quantitatively observing viral suppressor efficiency in plants. This suppressor assay demonstrates that plant viral suppressors greatly enhanced transient GFP expression, with P0 showing a more prolonged suppressor activity over time than HC-Pro. Both suppressors could prove to be ideal candidates for enhancing target protein expression in plants.

  20. Human cord blood suppressor T lymphocytes. II. Characterization of inducer of suppressor cells

    International Nuclear Information System (INIS)

    Cheng, H.; Delespesse, G.

    1986-01-01

    Previously, we reported an antigen nonspecific inducer of T suppressor cell factor (TisF) produced by cord blood mononuclear cells (MNC) in 48-hr, two-way mixed lymphocyte cultures (MLC). The target of this factor was a radiosensitive, T4+ (T8-) adult suppressor T cell subset. The cellular origin of this TisF was examined in the present study. IgG production by pokeweed mitogen (PWM)-stimulated adult MNC was used as an assay for TisF activity. It was found that TisF-producing cells formed rosettes with sheep erythrocytes (E+) and were independent of adherent cells (AC) in the production of TisF. They were resistant to irradiation (2500 rads) and phenotypic characterization with T cell reactive monoclonal antibodies indicated that they resided in the T8- (T4+) population. Furthermore, both TQ1- and TQ1+ cells were required for the production of TisF activity and such activity could not be reconstituted by supernatants from TQ1- MLC and TQ1+ MLC. These results indicate that the production of TisF is dependent upon interactions between radioresistant E+, T8-, TQ1- and radioresistant E+, T8-, TQ1+ cells

  1. Candidate luminal B breast cancer genes identified by genome, gene expression and DNA methylation profiling.

    Directory of Open Access Journals (Sweden)

    Stéphanie Cornen

    Full Text Available Breast cancers (BCs of the luminal B subtype are estrogen receptor-positive (ER+, highly proliferative, resistant to standard therapies and have a poor prognosis. To better understand this subtype we compared DNA copy number aberrations (CNAs, DNA promoter methylation, gene expression profiles, and somatic mutations in nine selected genes, in 32 luminal B tumors with those observed in 156 BCs of the other molecular subtypes. Frequent CNAs included 8p11-p12 and 11q13.1-q13.2 amplifications, 7q11.22-q34, 8q21.12-q24.23, 12p12.3-p13.1, 12q13.11-q24.11, 14q21.1-q23.1, 17q11.1-q25.1, 20q11.23-q13.33 gains and 6q14.1-q24.2, 9p21.3-p24,3, 9q21.2, 18p11.31-p11.32 losses. A total of 237 and 101 luminal B-specific candidate oncogenes and tumor suppressor genes (TSGs presented a deregulated expression in relation with their CNAs, including 11 genes previously reported associated with endocrine resistance. Interestingly, 88% of the potential TSGs are located within chromosome arm 6q, and seven candidate oncogenes are potential therapeutic targets. A total of 100 candidate oncogenes were validated in a public series of 5,765 BCs and the overexpression of 67 of these was associated with poor survival in luminal tumors. Twenty-four genes presented a deregulated expression in relation with a high DNA methylation level. FOXO3, PIK3CA and TP53 were the most frequent mutated genes among the nine tested. In a meta-analysis of next-generation sequencing data in 875 BCs, KCNB2 mutations were associated with luminal B cases while candidate TSGs MDN1 (6q15 and UTRN (6q24, were mutated in this subtype. In conclusion, we have reported luminal B candidate genes that may play a role in the development and/or hormone resistance of this aggressive subtype.

  2. Oncogenic activation of FOXR1 by 11q23 intrachromosomal deletion-fusions in neuroblastoma

    NARCIS (Netherlands)

    Santo, E. E.; Ebus, M. E.; Koster, J.; Schulte, J. H.; Lakeman, A.; van Sluis, P.; Vermeulen, J.; Gisselsson, D.; Øra, I.; Lindner, S.; Buckley, P. G.; Stallings, R. L.; Vandesompele, J.; Eggert, A.; Caron, H. N.; Versteeg, R.; Molenaar, J. J.

    2012-01-01

    Neuroblastoma tumors frequently show loss of heterozygosity of chromosome 11q with a shortest region of overlap in the 11q23 region. These deletions are thought to cause inactivation of tumor suppressor genes leading to haploinsufficiency. Alternatively, micro-deletions could lead to gene fusion

  3. Power consumption in positive ion beam converter with electrostatic electron suppressor

    International Nuclear Information System (INIS)

    Hashimoto, Kiyoshi; Sugawara, Tohru

    1985-01-01

    The power recovery characteristics of an in-line direct beam converter provided with electrostatic electron suppressor were studied numerically by tracing the orbits of fast primary ions and secondary charged particles generated along their beam path by collision with background gas molecules. It is shown that, in reference to the electrostatic field potential at the point of impact, the energy distribution of secondary ions impinging on the suppressor has two peaks-one corresponding to a zone of high positive potential surrounding the collector and the other to one of slightly negative potential around the electron suppressor. Secondary electron emission from the suppressor is ascribed mainly to the latter peak, associated with impingement of slower secondary ions. Far much power consumed in secondary particle acceleration is spent for emitting electrons from the suppressor than for secondary ions generated by beam-gas collision. The upper limit of background pressure is discussed on the basis of criteria prescribed for restricting the power consumed in this secondary particle acceleration, as for practical convenience of electrode cooling. Numerical examples are given of calculations based on particle trajectory analysis of both primary ions and secondary particles, for the case of a 100 keV-proton sheet beam 10 cm thick of 35 mA/cm 2 current density. (author)

  4. Cdh11 Acts as a Tumor Suppressor in a Murine Retinoblastoma Model by Facilitating Tumor Cell Death

    Science.gov (United States)

    Marchong, Mellone N.; Yurkowski, Christine; Ma, Clement; Spencer, Clarellen; Pajovic, Sanja; Gallie, Brenda L.

    2010-01-01

    CDH11 gene copy number and expression are frequently lost in human retinoblastomas and in retinoblastomas arising in TAg-RB mice. To determine the effect of Cdh11 loss in tumorigenesis, we crossed Cdh11 null mice with TAg-RB mice. Loss of Cdh11 had no gross morphological effect on the developing retina of Cdh11 knockout mice, but led to larger retinal volumes in mice crossed with TAg-RB mice (p = 0.01). Mice null for Cdh11 presented with fewer TAg-positive cells at postnatal day 8 (PND8) (p = 0.01) and had fewer multifocal tumors at PND28 (p = 0.016), compared to mice with normal Cdh11 alleles. However, tumor growth was faster in Cdh11-null mice between PND8 and PND84 (p = 0.003). In tumors of Cdh11-null mice, cell death was decreased 5- to 10-fold (p<0.03 for all markers), while proliferation in vivo remained unaffected (p = 0.121). Activated caspase-3 was significantly decreased and β-catenin expression increased in Cdh11 knockdown experiments in vitro. These data suggest that Cdh11 displays tumor suppressor properties in vivo and in vitro in murine retinoblastoma through promotion of cell death. PMID:20421947

  5. Cdh11 acts as a tumor suppressor in a murine retinoblastoma model by facilitating tumor cell death.

    Directory of Open Access Journals (Sweden)

    Mellone N Marchong

    2010-04-01

    Full Text Available CDH11 gene copy number and expression are frequently lost in human retinoblastomas and in retinoblastomas arising in TAg-RB mice. To determine the effect of Cdh11 loss in tumorigenesis, we crossed Cdh11 null mice with TAg-RB mice. Loss of Cdh11 had no gross morphological effect on the developing retina of Cdh11 knockout mice, but led to larger retinal volumes in mice crossed with TAg-RB mice (p = 0.01. Mice null for Cdh11 presented with fewer TAg-positive cells at postnatal day 8 (PND8 (p = 0.01 and had fewer multifocal tumors at PND28 (p = 0.016, compared to mice with normal Cdh11 alleles. However, tumor growth was faster in Cdh11-null mice between PND8 and PND84 (p = 0.003. In tumors of Cdh11-null mice, cell death was decreased 5- to 10-fold (p<0.03 for all markers, while proliferation in vivo remained unaffected (p = 0.121. Activated caspase-3 was significantly decreased and beta-catenin expression increased in Cdh11 knockdown experiments in vitro. These data suggest that Cdh11 displays tumor suppressor properties in vivo and in vitro in murine retinoblastoma through promotion of cell death.

  6. [Agrobacterium-mediated sunflower transformation (Helianthus annuus L.) in vitro and in Planta using strain of LBA4404 harboring binary vector pBi2E with dsRNA-suppressor proline dehydrogenase gene].

    Science.gov (United States)

    Tishchenko, E N; Komisarenko, A G; Mikhal'skaia, S I; Sergeeva, L E; Adamenko, N I; Morgun, B V; Kochetov, A V

    2014-01-01

    To estimate the efficiency of proline dehydrogenase gene suppression towards increasing of sunflower (Helianthus annuus L.) tolerance level to water deficit and salinity, we employed strain LBA4404 harboring pBi2E with double-stranded RNA-suppressor, which were prepared on basis arabidopsis ProDH1 gene. The techniques of Agrobacterium-mediated transformation in vitro and in planta during fertilization sunflower have been proposed. There was shown the genotype-depended integration of T-DNA in sunflower genome. PCR-analysis showed that ProDH1 presents in genome of inbred lines transformed in planta, as well as in T1- and T2-generations. In trans-genic regenerants the essential accumulation of free L-proline during early stages of in vitro cultivation under normal conditions was shown. There was established the essential accumulation of free proline in transgenic regenerants during cultivation under lethal stress pressure (0.4 M mannitol and 2.0% sea water salts) and its decline upon the recovery period. These data are declared about effectiveness of suppression of sunflower ProDH and gene participation in processes connected with osmotolerance.

  7. Gene therapy and radiotherapy in malignant tumor

    International Nuclear Information System (INIS)

    Zhang Yaowen; Cao Yongzhen; Li Jin; Wang Qin

    2008-01-01

    Tumor treatment is one of the most important fields in medical research. Nowadays, a novel method which is combined gene therapy with radiotherapy plays an important role in the field of cancer research, and mainly includes immune gene therapy combined with radiotherapy, suicide gene therapy or tumor suppressor gene therapy combined with radiotherapy, antiangiogenesis gene therapy combined with radiotherapy and protective gene therapy combined with radiotherapy based on the technical features. This review summarized the current status of combined therapies of gene therapy and radiotherapy and possible mechanism. (authors)

  8. Discrimination of Deletion and Duplication Subtypes of the Deleted in Azoospermia Gene Family in the Context of Frequent Interloci Gene Conversion

    Science.gov (United States)

    Vaszkó, Tibor; Papp, János; Krausz, Csilla; Casamonti, Elena; Géczi, Lajos; Olah, Edith

    2016-01-01

    Due to its palindromic setup, AZFc (Azoospermia Factor c) region of chromosome Y is one of the most unstable regions of the human genome. It contains eight gene families expressed mainly in the testes. Several types of rearrangement resulting in changes in the cumulative copy number of the gene families were reported to be associated with diseases such as male infertility and testicular germ cell tumors. The best studied AZFc rearrangement is gr/gr deletion. Its carriers show widespread phenotypic variation from azoospermia to normospermia. This phenomenon was initially attributed to different gr/gr subtypes that would eliminate distinct members of the affected gene families. However, studies conducted to confirm this hypothesis have brought controversial results, perhaps, in part, due to the shortcomings of the utilized subtyping methodology. This proof-of-concept paper is meant to introduce here a novel method aimed at subtyping AZFc rearrangements. It is able to differentiate the partial deletion and partial duplication subtypes of the Deleted in Azoospermia (DAZ) gene family. The keystone of the method is the determination of the copy number of the gene family member-specific variant(s) in a series of sequence family variant (SFV) positions. Most importantly, we present a novel approach for the correct interpretation of the variant copy number data to determine the copy number of the individual DAZ family members in the context of frequent interloci gene conversion.Besides DAZ1/DAZ2 and DAZ3/DAZ4 deletions, not yet described rearrangements such as DAZ2/DAZ4 deletion and three duplication subtypes were also found by the utilization of the novel approach. A striking feature is the extremely high concordance among the individual data pointing to a certain type of rearrangement. In addition to being able to identify DAZ deletion subtypes more reliably than the methods used previously, this approach is the first that can discriminate DAZ duplication subtypes as well

  9. MTUS1 tumor suppressor and its miRNA regulators in fibroadenoma and breast cancer.

    Science.gov (United States)

    Kara, Murat; Kaplan, Mehmet; Bozgeyik, Ibrahim; Ozcan, Onder; Celik, Ozgur Ilhan; Bozgeyik, Esra; Yumrutas, Onder

    2016-08-10

    Breast cancer is major public health problem predominantly effects female population. Current therapeutic approaches to deal with breast cancer are still lack of effectiveness. Thus, identifying/developing novel strategies to fight against breast cancer is very important. The frequent deletions at 8p21.3-22 chromosomal location nearby D8S254 marker enabled the discovery of a novel tumor suppressor gene, MTUS1. Subsequently, MTUS1 was demonstrated to be less expressed in a variety cancer types including breast cancer. Also, it is obvious that gene expression is widely regulated by miRNAs. Here, we aimed to report differential expression of MTUS1 and its regulatory miRNAs in breast cancer and fibroadenoma tissues. Dynamic analysis of MTUS1 expression levels and its miRNAs regulators were attained by Fluidigm 96×96 Dynamic Array Expression chips and reactions were performed in Fluidigm BioMark™ HD System qPCR. Consequently, MTUS1 mRNA levels were significantly diminished in breast cancer tissues and elevated in fibroadenoma tissues. Also, among MTUS1 targeting miRNAs, miR-183-5p was identified to be overexpressed in breast cancer and down-regulated in fibroadenoma tissues. Also, expression levels of MTUS1 and miR-183-5p were well correlated with clinical parameters. In particular, MTUS1 expression was found to be diminished and miR-183-5p expression was elevated with the advancing stage. In conclusion, as a potential therapeutic target, miR-183-5p can be a chief regulator of MTUS1 and MTUS1-miR-183-5p axis may have significant influence in the pathology of breast cancer. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The genetic alteration of retinoblastoma gene in esophageal cancer

    International Nuclear Information System (INIS)

    Cho, Jae Il; Shim, Yung Mok; Kim, Chang Min

    1994-12-01

    Retinoblastoma(RB) gene is the prototype of tumor suppressor gene and it's alteration have been frequently observed in a large number of human tumors. To investigate the role of RB in esophageal cancer, we studied 36 esophageal cancer tissues with Southern blot analysis to detect gross LOH and PCR-SSCP method to find minute LOH and mutation, if any. In the cases with abnormalities, the nucleotide sequence analysis was performed. Allelic loss of chromosome 13q14 occurred in 20 out of 32 informative cases (62.5%) by Southern analysis. Furthermore, PCR-LOH added three positive cases. Mobility shift by PCR-SSCP was observed in one case at exon 22, which showed 1 bp deletion in codon 771 of RB gene resulting in frame shift mutation. Besides, nine PCR-band alteration in tumor tissue compared with normal tissue were observed in exon 14 and 22, but mutation was not found on sequencing analysis suggesting the epigenetic alteration in tumor tissue. Analysis of the clinical data did not show any difference depending upon RB alteration. However, the total incidence of RB gene may play an important role in the development of esophageal cancer. The main genetic alteration of RB gene was deletion detected by Southern blot and one bp deletion leading to frame shift was also observed. 8 figs, 5 tabs. (Author)

  11. The genetic alteration of retinoblastoma gene in esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jae Il; Shim, Yung Mok; Kim, Chang Min [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-12-01

    Retinoblastoma(RB) gene is the prototype of tumor suppressor gene and it`s alteration have been frequently observed in a large number of human tumors. To investigate the role of RB in esophageal cancer, we studied 36 esophageal cancer tissues with Southern blot analysis to detect gross LOH and PCR-SSCP method to find minute LOH and mutation, if any. In the cases with abnormalities, the nucleotide sequence analysis was performed. Allelic loss of chromosome 13q14 occurred in 20 out of 32 informative cases (62.5%) by Southern analysis. Furthermore, PCR-LOH added three positive cases. Mobility shift by PCR-SSCP was observed in one case at exon 22, which showed 1 bp deletion in codon 771 of RB gene resulting in frame shift mutation. Besides, nine PCR-band alteration in tumor tissue compared with normal tissue were observed in exon 14 and 22, but mutation was not found on sequencing analysis suggesting the epigenetic alteration in tumor tissue. Analysis of the clinical data did not show any difference depending upon RB alteration. However, the total incidence of RB gene may play an important role in the development of esophageal cancer. The main genetic alteration of RB gene was deletion detected by Southern blot and one bp deletion leading to frame shift was also observed. 8 figs, 5 tabs. (Author).

  12. Steroidogenic factor-1 (SF-1 gene mutation as a frequent cause of primary amenorrhea in 46,XY female adolescents with low testosterone concentration

    Directory of Open Access Journals (Sweden)

    Servant Nadège

    2010-03-01

    Full Text Available Abstract Background Primary amenorrhea due to 46,XY disorders of sex differentiation (DSD is a frequent reason for consultation in endocrine and gynecology clinics. Among the genetic causes of low-testosterone primary amenorrhea due to 46,XY DSD, SRY gene is reported to be frequently involved, but other genes, such as SF1 and WT1, have never been studied for their prevalence. Methods We directly sequenced SRY, SF1 and WT1 genes in 15 adolescent girls with primary amenorrhea, low testosterone concentration, and XY karyotype, to determine the prevalence of mutations. We also analyzed the LH receptor gene in patients with high LH and normal FSH concentrations. Results Among the 15 adolescents with primary amenorrhea and low testosterone concentration, we identified two new SRY mutations, five new SF1 mutations and one new LH receptor gene mutation. Our study confirms the 10-15% prevalence of SRY mutations and shows the high prevalence (33% of SF1 abnormalities in primary amenorrhea due to 46,XY DSD with low plasma testosterone concentration. Conclusions The genetic analysis of low-testosterone primary amenorrhea is complex as several factors may be involved. This work underlines the need to systematically analyze the SF1 sequence in girls with primary amenorrhea due to 46,XY DSD and low testosterone, as well as in newborns with 46,XY DSD.

  13. [Breast cancer genetics. BRCA1 and BRCA2: the main genes for disease predisposition].

    Science.gov (United States)

    Ruiz-Flores, P; Calderón-Garcidueñas, A L; Barrera-Saldaña, H A

    2001-01-01

    Breast cancer is among the most common world cancers. In Mexico this neoplasm has been progressively increasing since 1990 and is expected to continue. The risk factors for this disease are age, some reproductive factors, ionizing radiation, contraceptives, obesity and high fat diets, among other factors. The main risk factor for BC is a positive family history. Several families, in which clustering but no mendelian inheritance exists, the BC is due probably to mutations in low penetrance genes and/or environmental factors. In families with autosomal dominant trait, the BRCA1 and BRCA2 genes are frequently mutated. These genes are the two main BC susceptibility genes. BRCA1 predispose to BC and ovarian cancer, while BRCA2 mutations predispose to BC in men and women. Both are long genes, tumor suppressors, functioning in a cell cycle dependent manner, and it is believed that both switch on the transcription of several genes, and participate in DNA repair. The mutations profile of these genes is known in developed countries, while in Latin America their search has just began. A multidisciplinary group most be responsible of the clinical management of patients with mutations in BRCA1 and BRCA2, and the risk assignment and Genetic counseling most be done carefully.

  14. MIM, a Potential Metastasis Suppressor Gene in Bladder Cancer

    Directory of Open Access Journals (Sweden)

    Young-Goo Lee

    2002-01-01

    Full Text Available Using a modified version of the mRNA differential display technique, five human bladder cancer cell lines from low grade to metastatic were analyzed to identify differences in gene expression. A 316-bp cDNA (C11300 was isolated that was not expressed in the metastatic cell line TccSuP. Sequence analysis revealed that this gene was identical to KIAA 0429, has a 5.3-kb transcript that mapped to 8824.1. The protein is predicted to be 356 amino acids in size and has an actin-binding WH2 domain. Northern blot revealed expression in multiple normal tissues, but none in a metastatic breast cancer cell line (SKBR3 or in metastatic prostatic cancer cell lines (LNCaP, PC3. We have named this gene Missing in Metastasis (MIM and our data suggest that it may be involved in cytoskeletal organization.

  15. Modulation and Expression of Tumor Suppressor Genes by Environmental Agents

    National Research Council Canada - National Science Library

    Ostrander, Gary Kent

    1996-01-01

    ... in the retinoblastoma gene in retinoblastoma and hepatocarcinomas following induction with known environmental carcinogens. Studies to date suggest the retinoblastoma gene/protein may play a role in oncogenesis in the medaka.

  16. Potential role of TRIM3 as a novel tumour suppressor in colorectal cancer (CRC) development.

    Science.gov (United States)

    Piao, Mei-Yu; Cao, Hai-Long; He, Na-Na; Xu, Meng-Que; Dong, Wen-Xiao; Wang, Wei-Qiang; Wang, Bang-Mao; Zhou, Bing

    2016-01-01

    Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in the United States. Recent cancer genome-sequencing efforts and complementary functional studies have led to the identification of a collection of candidate 'driver' genes involved in CRC tumorigenesis. Tripartite motif (TRIM3) is recently identified as a tumour suppressor in glioblastoma but this tumour-suppressive function has not been investigated in CRC. In this study, we investigated the potential role of TRIM3 as a tumour suppressor in CRC development by manipulating the expression of TRIM3 in two authentic CRC cell lines, HCT116 and DLD1, followed by various functional assays, including cell proliferation, colony formation, scratch wound healing, soft agar, and invasion assays. Xenograft experiment was performed to examine in vivo tumour-suppressive properties of TRIM3. Small-interfering RNA (siRNA) mediated knockdown of TRIM3 conferred growth advantage in CRC cells. In contrast, overexpression of TRIM3 affected cell survival, cell migration, anchorage independent growth and invasive potential in CRC cells. In addition, TRIM3 was found to be down-regulated in human colon cancer tissues compared with matched normal colon tissues. Overexpression of TRIM3 significantly inhibited tumour growth in vivo using xenograft mouse models. Mechanistic investigation revealed that TRIM3 can regulate p53 protein level through its stabilisation. TRIM3 functions as a tumour suppressor in CRC progression. This tumour-suppressive function is exerted partially through regulation of p53 protein. Therefore, this protein may represent a novel therapeutic target for prevention or intervention of CRC.

  17. Mutational myriad of tumor suppressor p53 in Filipino breast cancer: results and perspectives in molecular pathology and epidemiology

    Energy Technology Data Exchange (ETDEWEB)

    Deocaris, Custer C

    2000-04-01

    The p53 tumor suppressor is by far the most widely mutated gene in human cancers. p53 encodes a 53-kDa phosphoprotein, transcription-activator whose targets include genes and gene products that orchestrate genomic stability, cellular response to DNA damage, cell cycle progression apoptosis and aging (senescence). Analysis of the p53 gene profile has previously resulted in identifying several cancer-causative factors in the human setting, as well as, in creating a unique molecular profile of a tumor useful in the design of tailored-therapies for individual cancer patients. Our results in screening for p53 abnormalities in 140 Filipino patients with primary breast lesions confined from 1997-1998 in 5 major hospitals in Manila reveal that p53 plays an important role in the development and progression of breast cancer in at least 48% of all cases. Two methods of p53 analysis are employed, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction-temporal temperature gradient electrophoresis (PCR-TTGE). Inter-comparisons of method exhibit 63.3% concordance in 21 fresh breast carcinoma samples, with ELISA demonstrating 14% false-positives and 10% false-negatives. Only mutations in exon 7 (p=0.063) in the tumor samples how significant correlation with abnormal cellular elevation of p53. PCR-TTGE screening in a large series of 140 patients show that most genetic lesions are localized in exons 5 (41% of the total cases) and 6 (27% of the total cases). No mutations are, however, detected in the transactivation (exons 2-4) and oligomerization (exons 10-11) domains. Invasive carcinomas (stages II and III) are characterized with more frequent and diverse genetic alterations compared with benign tumors, most significantly at exon 5B (p=0.066) and at independently multiple sites (p=0.066). Earlier-onset cases (age of diagnosis < 50 yrs), known to be more clinico-pathologically aggressive, are diagnosed harboring more frequent p53 mutations centered at exon 7 (p=0

  18. Mutational myriad of tumor suppressor p53 in Filipino breast cancer: results and perspectives in molecular pathology and epidemiology

    International Nuclear Information System (INIS)

    Deocaris, Custer C.

    2000-04-01

    The p53 tumor suppressor is by far the most widely mutated gene in human cancers. p53 encodes a 53-kDa phosphoprotein, transcription-activator whose targets include genes and gene products that orchestrate genomic stability, cellular response to DNA damage, cell cycle progression apoptosis and aging (senescence). Analysis of the p53 gene profile has previously resulted in identifying several cancer-causative factors in the human setting, as well as, in creating a unique molecular profile of a tumor useful in the design of tailored-therapies for individual cancer patients. Our results in screening for p53 abnormalities in 140 Filipino patients with primary breast lesions confined from 1997-1998 in 5 major hospitals in Manila reveal that p53 plays an important role in the development and progression of breast cancer in at least 48% of all cases. Two methods of p53 analysis are employed, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction-temporal temperature gradient electrophoresis (PCR-TTGE). Inter-comparisons of method exhibit 63.3% concordance in 21 fresh breast carcinoma samples, with ELISA demonstrating 14% false-positives and 10% false-negatives. Only mutations in exon 7 (p=0.063) in the tumor samples how significant correlation with abnormal cellular elevation of p53. PCR-TTGE screening in a large series of 140 patients show that most genetic lesions are localized in exons 5 (41% of the total cases) and 6 (27% of the total cases). No mutations are, however, detected in the transactivation (exons 2-4) and oligomerization (exons 10-11) domains. Invasive carcinomas (stages II and III) are characterized with more frequent and diverse genetic alterations compared with benign tumors, most significantly at exon 5B (p=0.066) and at independently multiple sites (p=0.066). Earlier-onset cases (age of diagnosis < 50 yrs), known to be more clinico-pathologically aggressive, are diagnosed harboring more frequent p53 mutations centered at exon 7 (p=0

  19. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Directory of Open Access Journals (Sweden)

    Matei Irina

    2001-08-01

    Full Text Available Abstract Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP positive and negative gastric carcinomas (GCs. Methods We analyzed 50 gastric carcinomas (GCs for mutations in the BLM poly(A tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases but not in any of the MMP negative GCs (0/35 cases. The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %, BAX (27%, hMSH6 (20%,hMSH3 (13%, CBL (13%, IGFIIR (7%, RECQL (0% and WRN (0%. Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors.

  20. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Science.gov (United States)

    Calin, George; Ranzani, Guglielmina N; Amadori, Dino; Herlea, Vlad; Matei, Irina; Barbanti-Brodano, Giuseppe; Negrini, Massimo

    2001-01-01

    Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI) in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP) positive and negative gastric carcinomas (GCs). Methods We analyzed 50 gastric carcinomas (GCs) for mutations in the BLM poly(A) tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases) but not in any of the MMP negative GCs (0/35 cases). The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %), BAX (27%), hMSH6 (20%),hMSH3 (13%), CBL (13%), IGFIIR (7%), RECQL (0%) and WRN (0%). Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors. PMID:11532193

  1. Reverse engineering of TLX oncogenic transcriptional networks identifies RUNX1 as tumor suppressor in T-ALL.

    Science.gov (United States)

    Della Gatta, Giusy; Palomero, Teresa; Perez-Garcia, Arianne; Ambesi-Impiombato, Alberto; Bansal, Mukesh; Carpenter, Zachary W; De Keersmaecker, Kim; Sole, Xavier; Xu, Luyao; Paietta, Elisabeth; Racevskis, Janis; Wiernik, Peter H; Rowe, Jacob M; Meijerink, Jules P; Califano, Andrea; Ferrando, Adolfo A

    2012-02-26

    The TLX1 and TLX3 transcription factor oncogenes have a key role in the pathogenesis of T cell acute lymphoblastic leukemia (T-ALL). Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This systems biology analysis defined T cell leukemia homeobox 1 (TLX1) and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, a network structure analysis of this hierarchical network identified RUNX1 as a key mediator of the T-ALL induced by TLX1 and TLX3 and predicted a tumor-suppressor role for RUNX1 in T cell transformation. Consistent with these results, we identified recurrent somatic loss-of-function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 at the top of an oncogenic transcriptional network controlling leukemia development, show the power of network analyses to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor-suppressor gene in T-ALL.

  2. Frequent deletion of 3p21.1 region carrying semaphorin 3G and aberrant expression of the genes participating in semaphorin signaling in the epithelioid type of malignant mesothelioma cells.

    Science.gov (United States)

    Yoshikawa, Yoshie; Sato, Ayuko; Tsujimura, Tohru; Morinaga, Tomonori; Fukuoka, Kazuya; Yamada, Shusai; Murakami, Aki; Kondo, Nobuyuki; Matsumoto, Seiji; Okumura, Yoshitomo; Tanaka, Fumihiro; Hasegawa, Seiki; Hashimoto-Tamaoki, Tomoko; Nakano, Takashi

    2011-12-01

    Array-based comparative genomic hybridization analysis was performed on 21 malignant mesothelioma (MM) samples (16 primary cell cultures and 5 cell lines) and two reactive mesothelial hyperplasia (RM) primary cell cultures. The RM samples did not have any genomic losses or gains. In MM samples, deletions in 1p, 3p21, 4q, 9p21, 16p13 and 22q were detected frequently. We focused on 3p21 because this deletion was specific to the epithelioid type. Especially, a deletion in 3p21.1 region carrying seven genes including SEMA3G was found in 52% of MM samples (11 of 14 epithelioid samples). The allele loss of 3p21.1 might be a good marker for the epithelioid MM. A homozygous deletion in this region was detected in two MM primary cell cultures. A heterozygous deletion detected in nine samples contained the 3p21.1 region and 3p21.31 one carrying the candidate tumor suppressor genes such as semaphorin 3F (SEMA3F), SEMA3B and Ras association (RalGDS/AF-6) domain family member 1 (RASSF1A). SEMA3B, 3F and 3G are class 3 semaphorins and inhibit growth by competing with vascular endothelial growth factor (VEGF) through binding to neuropilin. All MM samples downregulated the expression of more than one gene for SEMA3B, 3F and 3G when compared with Met5a, a normal pleura-derived cell line. Moreover, in 12 of 14 epithelioid MM samples the expression level of SEMA3A was lower than that in Met5a and the two RM samples. An augmented expression of VEGFA was detected in half of the MM samples. The expression ratio of VEGFA/SEMA3A was significantly higher in the epithelioid MMs than in Met5a, RMs and the non-epithelioid MMs. Our data suggest that the downregulated expression of SEMA3A and several SEMA3s results in a loss of inhibitory activities in tumor angiogenesis and tumor growth of VEGFA; therefore, it may play an important role on the pathogenesis of the epithelioid type of MM.

  3. Tumor-suppressor activity of RRIG1 in breast cancer

    International Nuclear Information System (INIS)

    Zhang, Guihong; Brewster, Abenaa; Guan, Baoxiang; Fan, Zhen; Brown, Powel H; Xu, Xiao-Chun

    2011-01-01

    Retinoid receptor-induced gene-1 (RRIG1) is a novel gene that has been lost in several types of human cancers. The aim of this study was to determine whether RRIG1 plays a role in breast cancer, such as in the suppression of breast cancer cell growth and invasion. Immunohistochemistry was used to detect RRIG1 expression in breast tissue specimens. Gene transfection was used to restore or knock down RRIG1 expression in breast cancer cell lines for analysis of cell viability, colony formation, and migration/invasion potential. Reverse-transcription polymerase chain reaction and western blot assays were used to detect the changes in gene expression. The RhoA activation assay was used to assess RRIG1-induced inhibition of RhoA activity. The immunohistochemical data showed that RRIG1 expression was reduced in breast cancer tissues compared with normal and atypical hyperplastic breast tissues. RRIG1 expression was inversely correlated with lymph node metastasis of breast cancer but was not associated with the status of hormone receptors, such as estrogen receptor, progesterone receptor, or HER2. Furthermore, restoration of RRIG1 expression inhibited proliferation, colony formation, migration, and invasion of breast cancer cells. Expression of RRIG1 also reduced phosphorylated Erk1/2 and Akt levels; c-Jun, MMP9, and Akt expressions; and RhoA activity. In contrast, knockdown of RRIG1 expression promoted breast cancer cell proliferation, colony formation, migration, and invasion potential. The data from the current study indicated that RRIG1 expression was reduced or lost in breast cancer and that restoration of RRIG1 expression suppressed breast cancer cell growth and invasion capacity. Future studies will determine the underlying molecular mechanisms and define RRIG1 as a tumor-suppressor gene in breast cancer

  4. The Ebola virus VP35 protein is a suppressor of RNA silencing.

    Directory of Open Access Journals (Sweden)

    Joost Haasnoot

    2007-06-01

    Full Text Available RNA silencing or interference (RNAi is a gene regulation mechanism in eukaryotes that controls cell differentiation and developmental processes via expression of microRNAs. RNAi also serves as an innate antiviral defence response in plants, nematodes, and insects. This antiviral response is triggered by virus-specific double-stranded RNA molecules (dsRNAs that are produced during infection. To overcome antiviral RNAi responses, many plant and insect viruses encode RNA silencing suppressors (RSSs that enable them to replicate at higher titers. Recently, several human viruses were shown to encode RSSs, suggesting that RNAi also serves as an innate defence response in mammals. Here, we demonstrate that the Ebola virus VP35 protein is a suppressor of RNAi in mammalian cells and that its RSS activity is functionally equivalent to that of the HIV-1 Tat protein. We show that VP35 can replace HIV-1 Tat and thereby support the replication of a Tat-minus HIV-1 variant. The VP35 dsRNA-binding domain is required for this RSS activity. Vaccinia virus E3L protein and influenza A virus NS1 protein are also capable of replacing the HIV-1 Tat RSS function. These findings support the hypothesis that RNAi is part of the innate antiviral response in mammalian cells. Moreover, the results indicate that RSSs play a critical role in mammalian virus replication.

  5. Expression of circadian clock genes and proteins in urothelial cancer is related to cancer-associated genes

    International Nuclear Information System (INIS)

    Litlekalsoy, Jorunn; Rostad, Kari; Kalland, Karl-Henning; Hostmark, Jens G.; Laerum, Ole Didrik

    2016-01-01

    The purpose of this study was to evaluate invasive and metastatic potential of urothelial cancer by investigating differential expression of various clock genes/proteins participating in the 24 h circadian rhythms and to compare these gene expressions with transcription of other cancer-associated genes. Twenty seven paired samples of tumour and benign tissue collected from patients who underwent cystectomy were analysed and compared to 15 samples of normal bladder tissue taken from patients who underwent cystoscopy for benign prostate hyperplasia (unrelated donors). Immunohistochemical analyses were made for clock and clock-related proteins. In addition, the gene-expression levels of 22 genes (clock genes, casein kinases, oncogenes, tumour suppressor genes and cytokeratins) were analysed by real-time quantitative PCR (qPCR). Considerable up- or down-regulation and altered cellular distribution of different clock proteins, a reduction of casein kinase1A1 (CSNK1A1) and increase of casein kinase alpha 1 E (CSNK1E) were found. The pattern was significantly correlated with simultaneous up-regulation of stimulatory tumour markers, and a down-regulation of several suppressor genes. The pattern was mainly seen in aneuploid high-grade cancers. Considerable alterations were also found in the neighbouring bladder mucosa. The close correlation between altered expression of various clock genes and common tumour markers in urothelial cancer indicates that disturbed function in the cellular clock work may be an important additional mechanism contributing to cancer progression and malignant behaviour. The online version of this article (doi:10.1186/s12885-016-2580-y) contains supplementary material, which is available to authorized users

  6. Characterization of Two Novel Oncogenic Pathways Collaborating With Loss of P53 or Activated Neu in Mouse Models of Breast Cancer

    National Research Council Canada - National Science Library

    Lu, Jianrong; Leder, Philip

    2005-01-01

    Cancer develops through accumulation of multiple genetic mutations. Loss of tumor suppressor gene p53 and activation of oncogene Neu/ErbB2 are among the most frequent genetic alterations in human breast cancer...

  7. About hidden influence of predictor variables: Suppressor and mediator variables

    Directory of Open Access Journals (Sweden)

    Milovanović Boško

    2013-01-01

    Full Text Available In this paper procedure for researching hidden influence of predictor variables in regression models and depicting suppressor variables and mediator variables is shown. It is also shown that detection of suppressor variables and mediator variables could provide refined information about the research problem. As an example for applying this procedure, relation between Atlantic atmospheric centers and air temperature and precipitation amount in Serbia is chosen. [Projekat Ministarstva nauke Republike Srbije, br. 47007

  8. [Contact shot from infantry weapons with a flash-suppressor].

    Science.gov (United States)

    Perdekamp, Markus Grosse; Braunwarth, Roland; Schmidt, Ulrike; Schmidt, Wolfgang; Pollak, Stefan

    2003-01-01

    The number of reports on contact shots from firearms with a flash suppressor attached to the muzzle is small. On the basis of a case report (suicidal shot to the forehead with a Kalschnikow AKMS 47 assault rifle) the morphological peculiarities (characteristics soot pattern, relatively small powder cavity and only minor skin tears in the presence of a bony support) are presented and the conclusions to be drawn from the findings regarding the flash-suppressor, the shot distance, the angle of the shot and the way of holding the weapon are discussed.

  9. No evidence that genetic variation in the myeloid-derived suppressor cell pathway influences ovarian cancer survival

    DEFF Research Database (Denmark)

    Sucheston-Campbell, Lara E; Cannioto, Rikki; Clay, Alyssa I

    2017-01-01

    BACKGROUND: The precise mechanism by which the immune system is adversely affected in cancer patients remains poorly understood, but the accumulation of immune suppressive/pro-tumorigenic myeloid-derived suppressor cells (MDSCs) is thought to be one prominent mechanism contributing to immunologic...... tolerance of malignant cells in epithelial ovarian cancer (EOC). To this end, we hypothesized genetic variation in MDSC pathway genes would be associated with survival after EOC diagnoses. METHODS: We measured the hazard of death due to EOC within 10 years of diagnosis, overall and by invasive subtype...

  10. Modulation of allogeneic stimulation in man. I. Characterization of an in vitro induced suppressor macrophage population

    International Nuclear Information System (INIS)

    Stux, S.V.; Dubey, D.P.; Yunis, E.J.

    1981-01-01

    Cultured human peripheral blood mononuclear cells suppressed the allogeneic response of fresh autologous lymphocytes. This suppressor activity developed gradually over a period of one week. The cells primarily responsible for this effect were enriched by Ficoll density gradient centrifugation. It was found that the suppressor cell is a large, low density nylon wool adherent, radioresistant, phagocytic, and nonspecific esterase positive mononuclear cell. Moreover, these cells did not form E rosettes and were Fc positive. Electron microscopy confirmed that suppressor cells were macrophage like. Suppressor activity was not due to cytotoxicity, crowding, or steric hinderance by the cultured cells. The suppressor macrophage population did not appear to inhibit the allogeneic response via prostaglandin or arginase release, or interfere with the tritiated thymidine uptake by release of endogenous thymidine. The above system is viewed as an in vitro model of immune regulation by suppressor macrophages, in the context of allogeneic response

  11. Novel interactions of the von Hippel-Lindau (pVHL) tumor suppressor with the CDKN1 family of cell cycle inhibitors

    OpenAIRE

    Giovanni Minervini; Raffaele Lopreiato; Raissa Bortolotto; Antonella Falconieri; Geppo Sartori; Silvio C. E. Tosatto

    2017-01-01

    Germline inactivation of the von Hippel-Lindau (VHL) tumor suppressor predisposes patients to develop different highly vascularized cancers. pVHL targets the hypoxia-inducible transcription factor (HIF-1?) for degradation, modulating the activation of various genes involved in hypoxia response. Hypoxia plays a relevant role in regulating cell cycle progression, inducing growth arrest in cells exposed to prolonged oxygen deprivation. However, the exact molecular details driving this transition...

  12. Vaginal microbiota of women with frequent vulvovaginal candidiasis.

    Science.gov (United States)

    Zhou, Xia; Westman, Rachel; Hickey, Roxana; Hansmann, Melanie A; Kennedy, Colleen; Osborn, Thomas W; Forney, Larry J

    2009-09-01

    Vulvovaginal candidiasis (VVC) is an insidious infection that afflicts a large proportion of women of all ages, and 5 to 8% of affected women experience recurrent VVC (RVVC). The aim of this study was to explore the possible importance of vaginal bacterial communities in reducing the risk of RVVC. The species composition and diversity of microbial communities were evaluated for 42 women with and without frequent VVC based on profiles of terminal restriction fragment polymorphisms of 16S rRNA genes and phylogenetic analysis of cloned 16S rRNA gene sequences from the numerically dominant microbial populations. The data showed that there were no significant differences between the vaginal microbial communities of women in the two groups (likelihood score, 5.948; bootstrap P value, 0.26). Moreover, no novel bacteria were found in the communities of women with frequent VVC. The vaginal communities of most women in both groups (38/42; 90%) were dominated by species of Lactobacillus. The results of this study failed to provide evidence for the existence of altered or unusual vaginal bacterial communities in women who have frequent VVC compared to women who do not have frequent VVC. The findings suggest that commensal vaginal bacterial species may not be able to prevent VVC.

  13. Mutations in the LHX2 gene are not a frequent cause of micro/anophthalmia.

    Science.gov (United States)

    Desmaison, Annaïck; Vigouroux, Adeline; Rieubland, Claudine; Peres, Christine; Calvas, Patrick; Chassaing, Nicolas

    2010-12-18

    Microphthalmia and anophthalmia are at the severe end of the spectrum of abnormalities in ocular development. A few genes (orthodenticle homeobox 2 [OTX2], retina and anterior neural fold homeobox [RAX], SRY-box 2 [SOX2], CEH10 homeodomain-containing homolog [CHX10], and growth differentiation factor 6 [GDF6]) have been implicated mainly in isolated micro/anophthalmia but causative mutations of these genes explain less than a quarter of these developmental defects. The essential role of the LIM homeobox 2 (LHX2) transcription factor in early eye development has recently been documented. We postulated that mutations in this gene could lead to micro/anophthalmia, and thus performed molecular screening of its sequence in patients having micro/anophthalmia. Seventy patients having non-syndromic forms of colobomatous microphthalmia (n=25), isolated microphthalmia (n=18), or anophthalmia (n=17), and syndromic forms of micro/anophthalmia (n=10) were included in this study after negative molecular screening for OTX2, RAX, SOX2, and CHX10 mutations. Mutation screening of LHX2 was performed by direct sequencing of the coding sequences and intron/exon boundaries. Two heterozygous variants of unknown significance (c.128C>G [p.Pro43Arg]; c.776C>A [p.Pro259Gln]) were identified in LHX2 among the 70 patients. These variations were not identified in a panel of 100 control patients of mixed origins. The variation c.776C>A (p.Pro259Gln) was considered as non pathogenic by in silico analysis, while the variation c.128C>G (p.Pro43Arg) considered as deleterious by in silico analysis and was inherited from the asymptomatic father. Mutations in LHX2 do not represent a frequent cause of micro/anophthalmia.

  14. DNA Fragmentation Factor 45 (DFF45 Gene at 1p36.2 Is Homozygously Deleted and Encodes Variant Transcripts in Neuroblastoma Cell Line

    Directory of Open Access Journals (Sweden)

    Hong Wei Yang

    2001-01-01

    Full Text Available Recently, loss of heterozygosity (LOH studies suggest that more than two tumor suppressor genes lie on the short arm of chromosome 1 (1p in neuroblastoma (NB. To identify candidate tumor suppressor genes in NB, we searched for homozygous deletions in 20 NB cell lines using a high-density STS map spanning chromosome 1 p36, a common LOH region in NB. We found that the 45-kDa subunit of the DNA fragmentation factor (DFF45 gene was homozygously deleted in an NB cell line, NB-1. DFF45 is the chaperon of DFF40, and both molecules are necessary for caspase 3 to induce apoptosis. DFF35, a splicing variant of DFF45, is an inhibitor of DFF40. We examined 20 NB cell lines for expression and mutation of DFF45 gene by reverse transcription (RT-polymerase chain reaction (PCR and RT-PCR-single-strand conformation polymorphism. Some novel variant transcripts of the DFF45 gene were found in NB cell lines, but not in normal adrenal gland and peripheral blood. These variants may not serve as chaperons of DFF40, but as inhibitors like DFF35, thus disrupting the balance between DFF45 and DFF40. No mutations of the DFF45 gene were found in any NB cell line, suggesting that the DFF45 is not a tumor suppressor gene for NB. However, homozygous deletion of the DFF45 gene in the NB-1 cell line may imply the presence of unknown tumor suppressor genes in this region.

  15. Melanoma Suppressor Functions of the Carcinoma Oncogene FOXQ1

    Directory of Open Access Journals (Sweden)

    Archis Bagati

    2017-09-01

    Full Text Available Lineage-specific regulation of tumor progression by the same transcription factor is understudied. We find that levels of the FOXQ1 transcription factor, an oncogene in carcinomas, are decreased during melanoma progression. Moreover, in contrast to carcinomas, FOXQ1 suppresses epithelial-to-mesenchymal transition, invasion, and metastasis in melanoma cells. We find that these lineage-specific functions of FOXQ1 largely depend on its ability to activate (in carcinomas or repress (in melanoma transcription of the N-cadherin gene (CDH2. We demonstrate that FOXQ1 interacts with nuclear β-catenin and TLE proteins, and the β-catenin/TLE ratio, which is higher in carcinoma than melanoma cells, determines the effect of FOXQ1 on CDH2 transcription. Accordingly, other FOXQ1-dependent phenotypes can be manipulated by altering nuclear β-catenin or TLE proteins levels. Our data identify FOXQ1 as a melanoma suppressor and establish a mechanism underlying its inverse lineage-specific transcriptional regulation of transformed phenotypes.

  16. AZU-1: A Candidate Breast Tumor Suppressor and Biomarker for Tumor Progression

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Huei-Mei; Schmeichel, Karen L; Mian, I. Saira; Lelie`vre, Sophie; Petersen, Ole W; Bissell, Mina J

    2000-02-04

    To identify genes misregulated in the final stages of breast carcinogenesis, we performed differential display to compare the gene expression patterns of the human tumorigenic mammary epithelial cells, HMT-3522-T4-2, with those of their immediate premalignant progenitors, HMT-3522-S2. We identified a novel gene, called anti-zuai-1 (AZU-1), that was abundantly expressed in non- and premalignant cells and tissues but was appreciably reduced in breast tumor cell types and in primary tumors. The AZU-1 gene encodes an acidic 571-amino-acid protein containing at least two structurally distinct domains with potential protein-binding functions: an N-terminal serine and proline-rich domain with a predicted immunoglobulin-like fold and a C-terminal coiled-coil domain. In HMT-3522 cells, the bulk of AZU-1 protein resided in a detergent-extractable cytoplasmic pool and was present at much lower levels in tumorigenic T4-2 cells than in their nonmalignant counterparts. Reversion of the tumorigenic phenotype of T4-2 cells, by means described previously, was accompanied by the up-regulation of AZU-1. In addition, reexpression of AZU-1 in T4-2 cells, using viral vectors, was sufficient to reduce their malignant phenotype substantially, both in culture and in vivo. These results indicate that AZU-1 is a candidate breast tumor suppressor that may exert its effects by promoting correct tissue morphogenesis.

  17. CHD5 is required for neurogenesis and has a dual role in facilitating gene expression and polycomb gene repression

    DEFF Research Database (Denmark)

    Egan, Chris M; Nyman, Ulrika; Skotte, Julie

    2013-01-01

    The chromatin remodeler CHD5 is expressed in neural tissue and is frequently deleted in aggressive neuroblastoma. Very little is known about the function of CHD5 in the nervous system or its mechanism of action. Here we report that depletion of Chd5 in the developing neocortex blocks neuronal...... of this candidate tumor suppressor might contribute to neuroblastoma....

  18. Negative Regulation of the Stability and Tumor Suppressor Function of Fbw7 by the Pin1 Prolyl Isomerase

    Science.gov (United States)

    Min, Sang-Hyun; Lau, Alan W.; Lee, Tae Ho; Inuzuka, Hiroyuki; Wei, Shuo; Huang, Pengyu; Shaik, Shavali; Lee, Daniel Yenhong; Finn, Greg; Balastik, Martin; Chen, Chun-Hau; Luo, Manli; Tron, Adriana E.; DeCaprio, James A.; Zhou, Xiao Zhen; Wei, Wenyi; Lu, Kun Ping

    2012-01-01

    SUMMARY Fbw7 is the substrate recognition component of the SCF (Skp1-Cullin-F-box)-type E3 ligase complex and a well-characterized tumor suppressor that targets numerous oncoproteins for destruction. Genomic deletion or mutation of FBW7 has been frequently found in various types of human cancers, however, little is known about the upstream signaling pathway(s) governing Fbw7 stability and cellular functions. Here we report that Fbw7 protein destruction and tumor suppressor function are negatively regulated by the prolyl isomerase Pin1. Pin1 interacts with Fbw7 in a phoshorylation-dependent manner and promotes Fbw7 self-ubiquitination and protein degradation by disrupting Fbw7 dimerization. Consequently, over-expressing Pin1 reduces Fbw7 abundance and suppresses Fbw7’s ability to inhibit proliferation and transformation. By contrast, depletion of Pin1 in cancer cells leads to elevated Fbw7 expression, which subsequently reduces Mcl-1 abundance, sensitizing cancer cells to Taxol. Thus, Pin1-mediated inhibition of Fbw7 contributes to oncogenesis and Pin1 may be a promising drug target for anti-cancer therapy. PMID:22608923

  19. Loss of the NKX3.1 tumorsuppressor promotes the TMPRSS2-ERG fusion gene expression in prostate cancer

    International Nuclear Information System (INIS)

    Thangapazham, Rajesh; Saenz, Francisco; Katta, Shilpa; Mohamed, Ahmed A; Tan, Shyh-Han; Petrovics, Gyorgy; Srivastava, Shiv; Dobi, Albert

    2014-01-01

    In normal prostate epithelium the TMPRSS2 gene encoding a type II serine protease is directly regulated by male hormones through the androgen receptor. In prostate cancer ERG protooncogene frequently gains hormonal control by seizing gene regulatory elements of TMPRSS2 through genomic fusion events. Although, the androgenic activation of TMPRSS2 gene has been established, little is known about other elements that may interact with TMPRSS2 promoter sequences to modulate ERG expression in TMPRSS2-ERG gene fusion context. Comparative genomic analyses of the TMPRSS2 promoter upstream sequences and pathway analyses were performed by the Genomatix Software. NKX3.1 and ERG genes expressions were evaluated by immunoblot or by quantitative Real-Time PCR (qRT-PCR) assays in response to siRNA knockdown or heterologous expression. QRT-PCR assay was used for monitoring the gene expression levels of NKX3.1-regulated genes. Transcriptional regulatory function of NKX3.1 was assessed by luciferase assay. Recruitment of NKX3.1 to its cognate elements was monitored by Chromatin Immunoprecipitation assay. Comparative analysis of the TMPRSS2 promoter upstream sequences among different species revealed the conservation of binding sites for the androgen inducible NKX3.1 tumor suppressor. Defects of NKX3.1, such as, allelic loss, haploinsufficiency, attenuated expression or decreased protein stability represent established pathways in prostate tumorigenesis. We found that NKX3.1 directly binds to TMPRSS2 upstream sequences and negatively regulates the expression of the ERG protooncogene through the TMPRSS2-ERG gene fusion. These observations imply that the frequently noted loss-of-function of NKX3.1 cooperates with the activation of TMPRSS2-ERG fusions in prostate tumorigenesis

  20. Frequent down-regulation of ABC transporter genes in prostate cancer.

    Science.gov (United States)

    Demidenko, Rita; Razanauskas, Deividas; Daniunaite, Kristina; Lazutka, Juozas Rimantas; Jankevicius, Feliksas; Jarmalaite, Sonata

    2015-10-12

    ATP-binding cassette (ABC) transporters are transmembrane proteins responsible for the efflux of a wide variety of substrates, including steroid metabolites, through the cellular membranes. For better characterization of the role of ABC transporters in prostate cancer (PCa) development, the profile of ABC transporter gene expression was analyzed in PCa and noncancerous prostate tissues (NPT). TaqMan Low Density Array (TLDA) human ABC transporter plates were used for the gene expression profiling in 10 PCa and 6 NPT specimens. ABCB1 transcript level was evaluated in a larger set of PCa cases (N = 78) and NPT (N = 15) by real-time PCR, the same PCa cases were assessed for the gene promoter hypermethylation by methylation-specific PCR. Expression of eight ABC transporter genes (ABCA8, ABCB1, ABCC6, ABCC9, ABCC10, ABCD2, ABCG2, and ABCG4) was significantly down-regulated in PCa as compared to NPT, and only two genes (ABCC4 and ABCG1) were up-regulated. Down-regulation of ABC transporter genes was prevalent in the TMPRSS2-ERG-negative cases. A detailed analysis of ABCB1 expression confirmed TLDA results: a reduced level of the transcript was identified in PCa in comparison to NPT (p = 0.048). Moreover, the TMPRSS2-ERG-negative PCa cases showed significantly lower expression of ABCB1 in comparison to NPT (p = 0.003) or the fusion-positive tumors (p = 0.002). Promoter methylation of ABCB1 predominantly occurred in PCa and was rarely detected in NPT (p ABC transporter genes in PCa, especially in the TMPRSS2-ERG-negative tumors.

  1. Cell size checkpoint control by the retinoblastoma tumor suppressor pathway.

    Science.gov (United States)

    Fang, Su-Chiung; de los Reyes, Chris; Umen, James G

    2006-10-13

    Size control is essential for all proliferating cells, and is thought to be regulated by checkpoints that couple cell size to cell cycle progression. The aberrant cell-size phenotypes caused by mutations in the retinoblastoma (RB) tumor suppressor pathway are consistent with a role in size checkpoint control, but indirect effects on size caused by altered cell cycle kinetics are difficult to rule out. The multiple fission cell cycle of the unicellular alga Chlamydomonas reinhardtii uncouples growth from division, allowing direct assessment of the relationship between size phenotypes and checkpoint function. Mutations in the C. reinhardtii RB homolog encoded by MAT3 cause supernumerous cell divisions and small cells, suggesting a role for MAT3 in size control. We identified suppressors of an mat3 null allele that had recessive mutations in DP1 or dominant mutations in E2F1, loci encoding homologs of a heterodimeric transcription factor that is targeted by RB-related proteins. Significantly, we determined that the dp1 and e2f1 phenotypes were caused by defects in size checkpoint control and were not due to a lengthened cell cycle. Despite their cell division defects, mat3, dp1, and e2f1 mutants showed almost no changes in periodic transcription of genes induced during S phase and mitosis, many of which are conserved targets of the RB pathway. Conversely, we found that regulation of cell size was unaffected when S phase and mitotic transcription were inhibited. Our data provide direct evidence that the RB pathway mediates cell size checkpoint control and suggest that such control is not directly coupled to the magnitude of periodic cell cycle transcription.

  2. The in vitro and in vivo effects of re-expressing methylated von Hippel-Lindau tumor suppressor gene in clear cell renal carcinoma with 5-aza-2'-deoxycytidine.

    Science.gov (United States)

    Alleman, Wade G; Tabios, Ray L; Chandramouli, Gadisetti V R; Aprelikova, Olga N; Torres-Cabala, Carlos; Mendoza, Arnulfo; Rogers, Craig; Rodgers, Craig; Sopko, Nikolai A; Linehan, W Marston; Vasselli, James R

    2004-10-15

    Clear cell renal carcinoma (ccRCC) is strongly associated with loss of the von Hippel-Lindau (VHL) tumor suppressor gene. The VHL gene is functionally lost through hypermethylation in up to 19% of sporadic ccRCC cases. We theorized that re-expressing VHL silenced by methylation in ccRCC cells, using a hypo-methylating agent, may be an approach to treatment in patients with this type of cancer. We test the ability of two hypo-methylating agents to re-express VHL in cell culture and in mice bearing human ccRCC and evaluate the effects of re-expressed VHL in these models. Real-time reverse transcription-PCR was used to evaluate the ability of zebularine and 5-aza-2'-deoxycytidine (5-aza-dCyd) to re-express VHL in four ccRCC cell lines with documented VHL gene silencing through hypermethylation. We evaluated if the VHL re-expressed after hypo-methylating agent treatment could recreate similar phenotypic changes in ccRCC cells observed when the VHL gene is re-expressed via transfection in cell culture and in a xenograft mouse model. Finally we evaluate global gene expression changes occurring in our cells, using microarray analysis. 5-Aza-dCyd was able to re-express VHL in our cell lines both in culture and in xenografted murine tumors. Well described phenotypic changes of VHL expression including decreased invasiveness into Matrigel, and decreased vascular endothelial growth factor and glucose transporter-1 expression were observed in the treated lines. VHL methylated ccRCC xenografted tumors were significantly reduced in size in mice treated with 5-aza-dCyd. Mice bearing nonmethylated but VHL-mutated tumors showed no tumor shrinkage with 5-aza-dCyd treatment. Hypo-methylating agents may be useful in the treatment of patients having ccRCC tumors consisting of cells with methylated VHL.

  3. Nonspecific suppressor T cells cause decreased mixed lymphocyte culture reactivity in bone marrow transplant patients

    International Nuclear Information System (INIS)

    Harada, M.; Ueda, M.; Nakao, S.; Kondo, K.; Odaka, K.; Shiobara, S.; Matsue, K.; Mori, T.; Matsuda, T.

    1986-01-01

    Decreased reactivity in mixed lymphocyte culture (MLC) was observed in patients within 1 yr after allogeneic and autologous bone marrow transplantation. Suppressor activity of peripheral blood mononuclear cells (PBMC) from transplant patients was studied by adding these cells as modulator cells to a bidirectional MLC with cells from normal individuals. PBMC from transplant patients markedly suppressed MLC reactivity in a dose-dependent manner. Suppressor activity was present in cells forming rosettes with sheep erythrocytes. Treatment of modulator cells with monoclonal antibodies against T cell differentiation antigens (OKT8, OKIa1) and complement completely abolished suppression of MLC. Suppressor activity was unaffected by 30 Gy irradiation. Suppressor activity declined gradually after transplantation and was inversely correlated with MLC reactivity of each patient at a significant level (p less than 0.01). These observations suggest that OKT8+ Ia+ radioresistant suppressor T cells play a role in the development of decreased MLC reactivity observed during the early post-transplant period

  4. The Polerovirus silencing suppressor P0 targets ARGONAUTE proteins for degradation.

    Science.gov (United States)

    Baumberger, Nicolas; Tsai, Ching-Hsui; Lie, Miranda; Havecker, Ericka; Baulcombe, David C

    2007-09-18

    Plant and animal viruses encode suppressor proteins of an adaptive immunity mechanism in which viral double-stranded RNA is processed into 21-25 nt short interfering (si)RNAs. The siRNAs guide ARGONAUTE (AGO) proteins so that they target viral RNA. Most viral suppressors bind long dsRNA or siRNAs and thereby prevent production of siRNA or binding of siRNA to AGO. The one exception is the 2b suppressor of Cucumoviruses that binds to and inhibits AGO1. Here we describe a novel suppressor mechanism in which a Polerovirus-encoded F box protein (P0) targets the PAZ motif and its adjacent upstream sequence in AGO1 and mediates its degradation. F box proteins are components of E3 ubiquitin ligase complexes that add polyubiquitin tracts on selected lysine residues and thereby mark a protein for proteasome-mediated degradation. With P0, however, the targeted degradation of AGO is insensitive to inhibition of the proteasome, indicating that the proteasome is not involved. We also show that P0 does not block a mobile signal of silencing, indicating that the signal molecule does not have AGO protein components. The ability of P0 to block silencing without affecting signal movement may contribute to the phloem restriction of viruses in the Polerovirus group.

  5. Pharmacological activation of tumor suppressor, wild-type p53 as a promising strategy to fight cancer

    Directory of Open Access Journals (Sweden)

    Alicja Sznarkowska

    2010-08-01

    Full Text Available A powerful tumor suppressor – p53 protein is a transcription factor which plays a critical role in eliciting cellular responses to a variety of stress signals, including DNA damage, hypoxia and aberrant proliferative signals, such as oncogene activation. Since its discovery thirty one years ago, p53 has been connected to tumorigenesis as it accumulates in the transformed tumor cells. Cellular stress induces stabilization of p53 and promotes, depending on the stress level, cell cycle arrest or apoptosis in the irreversibly damaged cells. The p53 protein is found inactive in more than 50�0of human tumors either by enhanced proteasomal degradation or due to the inactivating point mutations in its gene. Numerous data indicate that low molecular weight compounds, identified by molecular modeling or in the functional, cell-based assays, efficiently activate non-mutated p53 in cancer cells which in consequence leads to their elimination due to p53-dependent apoptosis. In this work we describe the structure and cellular function of p53 as well as the latest discoveries on the compounds with high anti-tumor activities aiming at reactivation of the tumor suppressor function of p53.

  6. Recurrent selection on the Winters sex-ratio genes in Drosophila simulans.

    Science.gov (United States)

    Kingan, Sarah B; Garrigan, Daniel; Hartl, Daniel L

    2010-01-01

    Selfish genes, such as meiotic drive elements, propagate themselves through a population without increasing the fitness of host organisms. X-linked (or Y-linked) meiotic drive elements reduce the transmission of the Y (X) chromosome and skew progeny and population sex ratios, leading to intense conflict among genomic compartments. Drosophila simulans is unusual in having a least three distinct systems of X chromosome meiotic drive. Here, we characterize naturally occurring genetic variation at the Winters sex-ratio driver (Distorter on the X or Dox), its progenitor gene (Mother of Dox or MDox), and its suppressor gene (Not Much Yang or Nmy), which have been previously mapped and characterized. We survey three North American populations as well as 13 globally distributed strains and present molecular polymorphism data at the three loci. We find that all three genes show signatures of selection in North America, judging from levels of polymorphism and skews in the site-frequency spectrum. These signatures likely result from the biased transmission of the driver and selection on the suppressor for the maintenance of equal sex ratios. Coalescent modeling indicates that the timing of selection is more recent than the age of the alleles, suggesting that the driver and suppressor are coevolving under an evolutionary "arms race." None of the Winters sex-ratio genes are fixed in D. simulans, and at all loci we find ancestral alleles, which lack the gene insertions and exhibit high levels of nucleotide polymorphism compared to the derived alleles. In addition, we find several "null" alleles that have mutations on the derived Dox background, which result in loss of drive function. We discuss the possible causes of the maintenance of presence-absence polymorphism in the Winters sex-ratio genes.

  7. DMPD: Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18406369 Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins...svg) (.html) (.csml) Show Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins. ...PubmedID 18406369 Title Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins

  8. ERF is a Potential ERK Modulated Tumor Suppressor in Prostate Cancer

    Science.gov (United States)

    2016-10-01

    6/27/2016 - 6/27/2019 1.20 calendar Prostate Cancer Foundation (formerly CaP CURE) $ 75,000 Epigenetic ...AWARD NUMBER: W81XWH-15-1-0277 TITLE: ERF is a Potential ERK-Modulated Tumor Suppressor in Prostate Cancer PRINCIPAL INVESTIGATOR: Dr. Rohit...4. TITLE AND SUBTITLE ERF is a Potential ERK-Modulated Tumor Suppressor in Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0277

  9. ERF is a Potential ERK-Modulated Tumor Suppressor in Prostate Cancer

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-15-1-0277 TITLE: ERF is a Potential ERK-Modulated Tumor Suppressor in Prostate Cancer PRINCIPAL INVESTIGATOR: Dr...Rohit Bose CONTRACTING ORGANIZATION: Sloan Kettering Institute for Cancer Research New York NY 10065 REPORT DATE: October 2017 TYPE OF REPORT...4. TITLE AND SUBTITLE ERF is a Potential ERK-Modulated Tumor Suppressor in Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0277 5c

  10. Hereditary Ovarian Cancer: Not Only BRCA 1 and 2 Genes

    Directory of Open Access Journals (Sweden)

    Angela Toss

    2015-01-01

    Full Text Available More than one-fifth of ovarian tumors have hereditary susceptibility and, in about 65–85% of these cases, the genetic abnormality is a germline mutation in BRCA genes. Nevertheless, several other suppressor genes and oncogenes have been associated with hereditary ovarian cancers, including the mismatch repair (MMR genes in Lynch syndrome, the tumor suppressor gene, TP53, in the Li-Fraumeni syndrome, and several other genes involved in the double-strand breaks repair system, such as CHEK2, RAD51, BRIP1, and PALB2. The study of genetic discriminators and deregulated pathways involved in hereditary ovarian syndromes is relevant for the future development of molecular diagnostic strategies and targeted therapeutic approaches. The recent development and implementation of next-generation sequencing technologies have provided the opportunity to simultaneously analyze multiple cancer susceptibility genes, reduce the delay and costs, and optimize the molecular diagnosis of hereditary tumors. Particularly, the identification of mutations in ovarian cancer susceptibility genes in healthy women may result in a more personalized cancer risk management with tailored clinical and radiological surveillance, chemopreventive approaches, and/or prophylactic surgeries. On the other hand, for ovarian cancer patients, the identification of mutations may provide potential targets for biologic agents and guide treatment decision-making.

  11. Mutations and epimutations in the origin of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Peltomaeki, Paeivi, E-mail: Paivi.Peltomaki@Helsinki.Fi

    2012-02-15

    Cancer is traditionally viewed as a disease of abnormal cell proliferation controlled by a series of mutations. Mutations typically affect oncogenes or tumor suppressor genes thereby conferring growth advantage. Genomic instability facilitates mutation accumulation. Recent findings demonstrate that activation of oncogenes and inactivation of tumor suppressor genes, as well as genomic instability, can be achieved by epigenetic mechanisms as well. Unlike genetic mutations, epimutations do not change the base sequence of DNA and are potentially reversible. Similar to genetic mutations, epimutations are associated with specific patterns of gene expression that are heritable through cell divisions. Knudson's hypothesis postulates that inactivation of tumor suppressor genes requires two hits, with the first hit occurring either in somatic cells (sporadic cancer) or in the germline (hereditary cancer) and the second one always being somatic. Studies on hereditary and sporadic forms of colorectal carcinoma have made it evident that, apart from genetic mutations, epimutations may serve as either hit or both. Furthermore, recent next-generation sequencing studies show that epigenetic genes, such as those encoding histone modifying enzymes and subunits for chromatin remodeling systems, are themselves frequent targets of somatic mutations in cancer and can act like tumor suppressor genes or oncogenes. This review discusses genetic vs. epigenetic origin of cancer, including cancer susceptibility, in light of recent discoveries. Situations in which mutations and epimutations occur to serve analogous purposes are highlighted.

  12. A tumor suppressor role of the Bub3 spindle checkpoint protein after apoptosis inhibition

    Science.gov (United States)

    Moutinho-Santos, Tatiana

    2013-01-01

    Most solid tumors contain aneuploid cells, indicating that the mitotic checkpoint is permissive to the proliferation of chromosomally aberrant cells. However, mutated or altered expression of mitotic checkpoint genes accounts for a minor proportion of human tumors. We describe a Drosophila melanogaster tumorigenesis model derived from knocking down spindle assembly checkpoint (SAC) genes and preventing apoptosis in wing imaginal discs. Bub3-deficient tumors that were also deficient in apoptosis displayed neoplastic growth, chromosomal aneuploidy, and high proliferative potential after transplantation into adult flies. Inducing aneuploidy by knocking down CENP-E and preventing apoptosis does not induce tumorigenesis, indicating that aneuploidy is not sufficient for hyperplasia. In this system, the aneuploidy caused by a deficient SAC is not driving tumorigenesis because preventing Bub3 from binding to the kinetochore does not cause hyperproliferation. Our data suggest that Bub3 has a nonkinetochore-dependent function that is consistent with its role as a tumor suppressor. PMID:23609535

  13. Engineered reversal of drug resistance in cancer cells--metastases suppressor factors as change agents.

    Science.gov (United States)

    Yadav, Vinod Kumar; Kumar, Akinchan; Mann, Anita; Aggarwal, Suruchi; Kumar, Maneesh; Roy, Sumitabho Deb; Pore, Subrata Kumar; Banerjee, Rajkumar; Mahesh Kumar, Jerald; Thakur, Ram Krishna; Chowdhury, Shantanu

    2014-01-01

    Building molecular correlates of drug resistance in cancer and exploiting them for therapeutic intervention remains a pressing clinical need. To identify factors that impact drug resistance herein we built a model that couples inherent cell-based response toward drugs with transcriptomes of resistant/sensitive cells. To test this model, we focused on a group of genes called metastasis suppressor genes (MSGs) that influence aggressiveness and metastatic potential of cancers. Interestingly, modeling of 84 000 drug response transcriptome combinations predicted multiple MSGs to be associated with resistance of different cell types and drugs. As a case study, on inducing MSG levels in a drug resistant breast cancer line resistance to anticancer drugs caerulomycin, camptothecin and topotecan decreased by more than 50-60%, in both culture conditions and also in tumors generated in mice, in contrast to control un-induced cells. To our knowledge, this is the first demonstration of engineered reversal of drug resistance in cancer cells based on a model that exploits inherent cellular response profiles.

  14. RNAi suppressors encoded by pathogenic human viruses

    NARCIS (Netherlands)

    de Vries, Walter; Berkhout, Ben

    2008-01-01

    RNA silencing or RNAi interference (RNAi) serves as an innate antiviral mechanism in plants, fungi and animals. Human viruses, like plant viruses, encode suppressor proteins or RNAs that block or modulate the RNAi pathway. This review summarizes the mechanisms by which pathogenic human viruses

  15. Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Gehrau, Ricardo C.; D' Astolfo, Diego S.; Andreoli, Veronica [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Bocco, Jose L., E-mail: jbocco@fcq.unc.edu.ar [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Koritschoner, Nicolas P. [Centro de Investigaciones en Bioquimica Clinica e Inmunologia (CIBICI-CONICET), Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2011-02-10

    The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC{sub 50}). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p < 0.0001) in KLF6 mRNA levels were observed depending on the cellular p53 status upon cell damage. KLF6 expression was significantly increased in 63% of p53-deficient cells (122/195). Conversely, KLF6 mRNA level decreased nearly 4 fold in more than 70% of p53+/+ cells. In addition, klf6 gene promoter activity was down-regulated by DNA damaging agents in cells expressing the functional p53 protein whereas it was moderately increased in the absence of functional p53. Consistent results were obtained for the endogenous KLF6 protein level. Results indicate that human klf6 gene expression is responsive to external cell damage mediated by IC{sub 50} concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable

  16. The human LIS1 is downregulated in hepatocellular carcinoma and plays a tumor suppressor function

    International Nuclear Information System (INIS)

    Xing, Zhen; Tang, Xin; Gao, Yuan; Da, Liang; Song, Hai; Wang, Suiquan; Tiollais, Pierre; Li, Tsaiping; Zhao, Mujun

    2011-01-01

    Highlights: → LIS1 mRNA and protein levels are decreased in 70% HCC tissues. → Downregulation of LIS1 expression induces oncogenic transformation of QSG7701 and NIH3T3 cells in vitro and in vivo. → LIS1 downregulation leads to mitotic errors including spindle and chromosome defects. → Ectopic expression of LIS1 could significantly inhibit HCC cell proliferation and colony formation. → Our results suggest that LIS1 plays a potential tumor suppressor role in the development and progression of HCC. -- Abstract: The human lissencephaly-1 gene (LIS1) is a disease gene responsible for Miller-Dieker lissencephaly syndrome (MDL). LIS1 gene is located in the region of chromosome 17p13.3 that is frequency deleted in MDL patients and in human liver cancer cells. However, the expression and significance of LIS1 in liver cancer remain unknown. Here, we investigated the expression of LIS1 in hepatocellular carcinoma (HCC) tissues by real-time PCR, Western blot, and immunohistochemistry. The results indicated that the mRNA and protein levels of LIS1 were downregulated in about 70% of HCC tissues, and this downregulation was significantly associated with tumor progression. Functional studies showed that the reduction of LIS1 expression in the normal human liver cell line QSG7701 or the mouse fibroblast cell line NIH3T3 by shRNA resulted in colony formation in soft agar and xenograft tumor formation in nude mice, demonstrating that a decrease in the LIS1 level can promote the oncogenic transformation of cells. We also observed that the phenotypes of LIS1-knockdown cells displayed various defective mitotic structures, suggesting that the mechanism by which reduced LIS1 levels results in tumorigenesis is associated with its role in mitosis. Furthermore, we demonstrated that ectopic expression of LIS1 could significantly inhibit HCC cell proliferation and colony formation. Our results suggest that LIS1 plays a potential tumor suppressor role in the development and

  17. The human LIS1 is downregulated in hepatocellular carcinoma and plays a tumor suppressor function

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Zhen; Tang, Xin; Gao, Yuan; Da, Liang; Song, Hai; Wang, Suiquan [State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Tiollais, Pierre [Unite' d' Organisation Nucleaire et Oncogenese, INSERM U.579, Institut Pasteur, Paris (France); Li, Tsaiping [State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Zhao, Mujun, E-mail: mjzhao@sibs.ac.cn [State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China)

    2011-06-03

    Highlights: {yields} LIS1 mRNA and protein levels are decreased in 70% HCC tissues. {yields} Downregulation of LIS1 expression induces oncogenic transformation of QSG7701 and NIH3T3 cells in vitro and in vivo. {yields} LIS1 downregulation leads to mitotic errors including spindle and chromosome defects. {yields} Ectopic expression of LIS1 could significantly inhibit HCC cell proliferation and colony formation. {yields} Our results suggest that LIS1 plays a potential tumor suppressor role in the development and progression of HCC. -- Abstract: The human lissencephaly-1 gene (LIS1) is a disease gene responsible for Miller-Dieker lissencephaly syndrome (MDL). LIS1 gene is located in the region of chromosome 17p13.3 that is frequency deleted in MDL patients and in human liver cancer cells. However, the expression and significance of LIS1 in liver cancer remain unknown. Here, we investigated the expression of LIS1 in hepatocellular carcinoma (HCC) tissues by real-time PCR, Western blot, and immunohistochemistry. The results indicated that the mRNA and protein levels of LIS1 were downregulated in about 70% of HCC tissues, and this downregulation was significantly associated with tumor progression. Functional studies showed that the reduction of LIS1 expression in the normal human liver cell line QSG7701 or the mouse fibroblast cell line NIH3T3 by shRNA resulted in colony formation in soft agar and xenograft tumor formation in nude mice, demonstrating that a decrease in the LIS1 level can promote the oncogenic transformation of cells. We also observed that the phenotypes of LIS1-knockdown cells displayed various defective mitotic structures, suggesting that the mechanism by which reduced LIS1 levels results in tumorigenesis is associated with its role in mitosis. Furthermore, we demonstrated that ectopic expression of LIS1 could significantly inhibit HCC cell proliferation and colony formation. Our results suggest that LIS1 plays a potential tumor suppressor role in the

  18. The ubiquitin peptidase UCHL1 induces G0/G1 cell cycle arrest and apoptosis through stabilizing p53 and is frequently silenced in breast cancer.

    Directory of Open Access Journals (Sweden)

    Tingxiu Xiang

    Full Text Available Breast cancer (BrCa is a complex disease driven by aberrant gene alterations and environmental factors. Recent studies reveal that abnormal epigenetic gene regulation also plays an important role in its pathogenesis. Ubiquitin carboxyl- terminal esterase L1 (UCHL1 is a tumor suppressor silenced by promoter methylation in multiple cancers, but its role and alterations in breast tumorigenesis remain unclear.We found that UCHL1 was frequently downregulated or silenced in breast cancer cell lines and tumor tissues, but readily expressed in normal breast tissues and mammary epithelial cells. Promoter methylation of UCHL1 was detected in 9 of 10 breast cancer cell lines (90% and 53 of 66 (80% primary tumors, but rarely in normal breast tissues, which was statistically correlated with advanced clinical stage and progesterone receptor status. Pharmacologic demethylation reactivated UCHL1 expression along with concomitant promoter demethylation. Ectopic expression of UCHL1 significantly suppressed the colony formation and proliferation of breast tumor cells, through inducing G0/G1 cell cycle arrest and apoptosis. Subcellular localization study showed that UCHL1 increased cytoplasmic abundance of p53. We further found that UCHL1 induced p53 accumulation and reduced MDM2 protein level, and subsequently upregulated the expression of p21, as well as cleavage of caspase3 and PARP, but not in catalytic mutant UCHL1 C90S-expressed cells.UCHL1 exerts its tumor suppressive functions by inducing G0/G1cell cycle arrest and apoptosis in breast tumorigenesis, requiring its deubiquitinase activity. Its frequent silencing by promoter CpG methylation may serve as a potential tumor marker for breast cancer.

  19. Detecting cervical cancer by quantitative promoter hypermethylation assay on cervical scrapings : A feasibility study

    NARCIS (Netherlands)

    Reesink-Peters, N; Wisman, G.B.A.; Jeronimo, C; Tokumaru, CY; Cohen, Y; Dong, SM; Klip, HG; Buikema, HJ; Suurmeijer, AJH; Hollema, H; Boezen, HM; Sidransky, D; van der Zee, AGJ

    Current morphology-based cervical cancer screening is associated with significant false-positive and false-negative results. Tumor suppressor gene hypermethylation is frequently present in cervical cancer. It is unknown whether a cervical scraping reflects the methylation status of the underlying

  20. New recurrent deletions in the PPARgamma and TP53 genes are associated with childhood myelodysplastic syndrome

    DEFF Research Database (Denmark)

    Silveira, Cássia G T; Oliveira, Fábio M; Valera, Elvis T

    2009-01-01

    Myelodysplastic syndrome (MDS) is a rare hematological malignancy in children. It was performed FISH analysis in 19 pediatric MDS patients to investigate deletions involving the PPARgamma and TP53 genes. Significant losses in the PPARgamma gene and deletions in the tumor suppressor gene TP53 were...

  1. Differential expression of the klf6 tumor suppressor gene upon cell damaging treatments in cancer cells

    International Nuclear Information System (INIS)

    Gehrau, Ricardo C.; D'Astolfo, Diego S.; Andreoli, Veronica; Bocco, Jose L.; Koritschoner, Nicolas P.

    2011-01-01

    The mammalian Krueppel-like factor 6 (KLF6) is involved in critical roles such as growth-related signal transduction, cell proliferation and differentiation, development, apoptosis and angiogenesis. Also, KLF6 appears to be an emerging key factor during cancer development and progression. Its expression is thoroughly regulated by several cell-damaging stimuli. DNA damaging agents at lethal concentrations induce a p53-independent down-regulation of the klf6 gene. To investigate the impact of external stimuli on human klf6 gene expression, its mRNA level was analyzed using a cancer cell line profiling array system, consisting in an assortment of immobilized cDNAs from multiple cell lines treated with several cell-damaging agents at growth inhibitory concentrations (IC 50 ). Cell-damaging agents affected the klf6 expression in 62% of the cDNA samples, though the expression pattern was not dependent on the cell origin type. Interestingly, significant differences (p 50 concentrations of physical and chemical stimuli in a p53-dependent manner. Most of these agents are frequently used in cancer therapy. Induction of klf6 expression in the absence of functional p53 directly correlates with cell death triggered by these compounds, whereas it is down-regulated in p53+/+ cells. Hence, klf6 expression level could represent a valuable marker for the efficiency of cell death upon cancer treatment.

  2. Multielement suppressor nozzles for thrust augmentation systems.

    Science.gov (United States)

    Lawrence, R. L.; O'Keefe, J. V.; Tate, R. B.

    1972-01-01

    The noise reduction and nozzle performance characteristics of large-scale, high-aspect-ratio multielement nozzle arrays operated at low velocities were determined by test. The nozzles are selected for application to high-aspect-ratio augmentor suppressors to be used for augmentor wing airplanes. Significant improvements in noise characteristics for multielement nozzles over those of round or high-aspect-ratio slot nozzles are obtained. Elliptical noise patterns typical of slot nozzles are presented for high-aspect-ratio multielement nozzle arrays. Additional advantages are available in OASPL noise reduction from the element size and spacing. Augmentor-suppressor systems can be designed for maximum beam pattern directivity and frequency spectrum shaping advantages. Measurements of the nozzle wakes show a correlation with noise level data and frequency spectrum peaks. The noise and jet wake results are compared with existing prediction procedures based on empirical jet flow equations, Lighthill relationships, Strouhal number, and empirical shock-induced screech noise effects.

  3. Phylogenetic Studies of the Three RNA Silencing Suppressor Genes of South American CTV Isolates Reveal the Circulation of a Novel Genetic Lineage

    Directory of Open Access Journals (Sweden)

    María José Benítez-Galeano

    2015-07-01

    Full Text Available Citrus Tristeza Virus (CTV is the most economically important virus of citrus worldwide. Genetic diversity and population structure of CTV isolates from all citrus growing areas from Uruguay were analyzed by RT-PCR and cloning of the three RNA silencing suppressor genes (p25, p20 and p23. Bayesian phylogenetic analysis revealed the circulation of three known genotypes (VT, T3, T36 in the country, and the presence of a new genetic lineage composed by isolates from around the world, mainly from South America. Nucleotide and amino acid identity values for this new genetic lineage were both higher than 97% for the three analyzed regions. Due to incongruent phylogenetic relationships, recombination analysis was performed using Genetic Algorithms for Recombination Detection (GARD and SimPlot software. Recombination events between previously described CTV isolates were detected. High intra-sample variation was found, confirming the co-existence of different genotypes into the same plant. This is the first report describing: (1 the genetic diversity of Uruguayan CTV isolates circulating in the country and (2 the circulation of a novel CTV genetic lineage, highly present in the South American region. This information may provide assistance to develop an effective cross-protection program.

  4. Genetic alterations in head and neck squamous cell carcinomas

    Directory of Open Access Journals (Sweden)

    Nagai M.A.

    1999-01-01

    Full Text Available The genetic alterations observed in head and neck cancer are mainly due to oncogene activation (gain of function mutations and tumor suppressor gene inactivation (loss of function mutations, leading to deregulation of cell proliferation and death. These genetic alterations include gene amplification and overexpression of oncogenes such as myc, erbB-2, EGFR and cyclinD1 and mutations, deletions and hypermethylation leading to p16 and TP53 tumor suppressor gene inactivation. In addition, loss of heterozygosity in several chromosomal regions is frequently observed, suggesting that other tumor suppressor genes not yet identified could be involved in the tumorigenic process of head and neck cancers. The exact temporal sequence of the genetic alterations during head and neck squamous cell carcinoma (HNSCC development and progression has not yet been defined and their diagnostic or prognostic significance is controversial. Advances in the understanding of the molecular basis of head and neck cancer should help in the identification of new markers that could be used for the diagnosis, prognosis and treatment of the disease.

  5. Giant Subependymoma Developed in a Patient with Aniridia: Analyses of PAX6 and Tumor-relevant Genes

    Science.gov (United States)

    Maekawa, Motoko; Fujisawa, Hironori; Iwayama, Yoshimi; Tamase, Akira; Toyota, Tomoko; Osumi, Noriko; Yoshikawa, Takeo

    2010-01-01

    We observed an unusually large subependymoma in a female patient with congenital aniridia. To analyze the genetic mechanisms of tumorigenesis, we first examined the paired box 6 (PAX6) gene using both tumor tissue and peripheral lymphocytes. Tumor suppressor activity has been proposed for PAX6 in gliomas, in addition to its well-known role in the eye development. Using genomic quantitative PCR and loss of heterozygosity analysis, we identified hemizygous deletions in the 5′-region of PAX6. In lymphocytes, the deletion within PAX6 spanned from between exons 6 and 7 to the 5′-upstream region of the gene, but did not reach the upstream gene, RNC1, which is reported to be associated with tumors. The subependymoma had an additional de novo deletion spanning from the intron 4 to intron 6 of PAX6, although we could not completely determine whether these two deletions are on the same chromosome or not. We also examined other potentially relevant tumor suppressor genes: PTEN, TP53 and SOX2. However, we detected no exonic mutations or deletions in these genes. Collectively, we speculate that the defect in PAX6 may have contributed to the extremely large size of the subependymoma, due to a loss of tumor suppressor activity in glial cell lineage. PMID:20500513

  6. The Heterologous Expression of the p22 RNA Silencing Suppressor of the Crinivirus Tomato Chlorosis Virus from Tobacco Rattle Virus and Potato Virus X Enhances Disease Severity but Does Not Complement Suppressor-Defective Mutant Viruses.

    Science.gov (United States)

    Landeo-Ríos, Yazmín; Navas-Castillo, Jesús; Moriones, Enrique; Cañizares, M. Carmen

    2017-11-24

    To counteract host antiviral RNA silencing, plant viruses express suppressor proteins that function as pathogenicity enhancers. The genome of the Tomato chlorosis virus (ToCV) (genus Crinivirus , family Closteroviridae ) encodes an RNA silencing suppressor, the protein p22, that has been described as having one of the longest lasting local suppressor activities when assayed in Nicotiana benthamiana . Since suppression of RNA silencing and the ability to enhance disease severity are closely associated, we analyzed the effect of expressing p22 in heterologous viral contexts. Thus, we studied the effect of the expression of ToCV p22 from viral vectors Tobacco rattle virus (TRV) and Potato virus X (PVX), and from attenuated suppressor mutants in N. benthamiana plants. Our results show that although an exacerbation of disease symptoms leading to plant death was observed in the heterologous expression of ToCV p22 from both viruses, only in the case of TRV did increased viral accumulation occur. The heterologous expression of ToCV p22 could not complement suppressor-defective mutant viruses.

  7. Supervised learning classification models for prediction of plant virus encoded RNA silencing suppressors.

    Directory of Open Access Journals (Sweden)

    Zeenia Jagga

    Full Text Available Viral encoded RNA silencing suppressor proteins interfere with the host RNA silencing machinery, facilitating viral infection by evading host immunity. In plant hosts, the viral proteins have several basic science implications and biotechnology applications. However in silico identification of these proteins is limited by their high sequence diversity. In this study we developed supervised learning based classification models for plant viral RNA silencing suppressor proteins in plant viruses. We developed four classifiers based on supervised learning algorithms: J48, Random Forest, LibSVM and Naïve Bayes algorithms, with enriched model learning by correlation based feature selection. Structural and physicochemical features calculated for experimentally verified primary protein sequences were used to train the classifiers. The training features include amino acid composition; auto correlation coefficients; composition, transition, and distribution of various physicochemical properties; and pseudo amino acid composition. Performance analysis of predictive models based on 10 fold cross-validation and independent data testing revealed that the Random Forest based model was the best and achieved 86.11% overall accuracy and 86.22% balanced accuracy with a remarkably high area under the Receivers Operating Characteristic curve of 0.95 to predict viral RNA silencing suppressor proteins. The prediction models for plant viral RNA silencing suppressors can potentially aid identification of novel viral RNA silencing suppressors, which will provide valuable insights into the mechanism of RNA silencing and could be further explored as potential targets for designing novel antiviral therapeutics. Also, the key subset of identified optimal features may help in determining compositional patterns in the viral proteins which are important determinants for RNA silencing suppressor activities. The best prediction model developed in the study is available as a

  8. Frequent activation of EGFR in advanced chordomas

    Directory of Open Access Journals (Sweden)

    Dewaele Barbara

    2011-07-01

    Full Text Available Abstract Background Chordomas are rare neoplasms, arising from notochordal remnants in the midline skeletal axis, for which the current treatment is limited to surgery and radiotherapy. Recent reports suggest that receptor tyrosine kinases (RTK might be essential for the survival or proliferation of chordoma cells, providing a rationale for RTK targeted therapy. Nevertheless, the reported data are conflicting, most likely due to the assorted tumor specimens used for the studies and the heterogeneous methodological approaches. In the present study, we performed a comprehensive characterization of this rare entity using a wide range of assays in search for relevant therapeutic targets. Methods Histopathological features of 42 chordoma specimens, 21 primary and 21 advanced, were assessed by immunohistochemistry and fluorescent in situ hybridization (FISH using PDGFRB, CSF1R, and EGFR probes. Twenty-two of these cases, for which frozen material was available (nine primary and 13 advanced tumors, were selectively analyzed using the whole-genome 4.3 K TK-CGH-array, phospho-kinase antibody array or Western immunoblotting. The study was supplemented by direct sequencing of KIT, PDGFRB, CSF1R and EGFR. Results We demonstrated that EGFR is frequently and the most significantly activated RTK in chordomas. Furthermore, concurrent to EGFR activation, the tumors commonly reveal co-activation of alternative RTK. The consistent activation of AKT, the frequent loss of the tumor suppressor PTEN allele, the recurrent activation of upstream RTK and of downstream effectors like p70S6K and mTOR, all indicate the PI3K/AKT pathway as an important mediator of transformation in chordomas. Conclusions Given the complexity of the signaling in chordomas, combined treatment regimens targeting multiple RTK and downstream effectors are likely to be the most effective in these tumors. Personalized therapy with careful selection of the patients, based on the molecular profile of

  9. Tumor targeted gene therapy

    International Nuclear Information System (INIS)

    Kang, Joo Hyun

    2006-01-01

    Knowledge of molecular mechanisms governing malignant transformation brings new opportunities for therapeutic intervention against cancer using novel approaches. One of them is gene therapy based on the transfer of genetic material to an organism with the aim of correcting a disease. The application of gene therapy to the cancer treatment had led to the development of new experimental approaches such as suicidal gene therapy, inhibition of oncogenes and restoration of tumor-suppressor genes. Suicidal gene therapy is based on the expression in tumor cells of a gene encoding an enzyme that converts a prodrug into a toxic product. Representative suicidal genes are Herpes simplex virus type 1 thymidine kinase (HSV1-tk) and cytosine deaminase (CD). Especially, physicians and scientists of nuclear medicine field take an interest in suicidal gene therapy because they can monitor the location and magnitude, and duration of expression of HSV1-tk and CD by PET scanner

  10. Suppressor Effects of Positive and Negative Religious Coping on Academic Burnout Among Korean Middle School Students.

    Science.gov (United States)

    Noh, Hyunkyung; Chang, Eunbi; Jang, Yoojin; Lee, Ji Hae; Lee, Sang Min

    2016-02-01

    Statistical suppressor effects in prediction models can provide evidence of the interdependent relationship of independent variables. In this study, the suppressor effects of positive and negative religious coping on academic burnout were examined using longitudinal data. First, 388 middle school students reported their type of religion and use of positive and negative religious coping strategies. Four months later, they also reported their level of academic burnout. From structural equation modeling, significant suppressor effects were found among religious students. That is, the coefficients became larger when both positive and negative religious coping predicted academic burnout simultaneously, compared to when each religious coping predicted academic burnout alone. However, suppressor effects were not found among non-religious students.

  11. Functional Analysis of In-frame Indel ARID1A Mutations Reveals New Regulatory Mechanisms of Its Tumor Suppressor Functions

    Directory of Open Access Journals (Sweden)

    Bin Guan

    2012-10-01

    Full Text Available AT-rich interactive domain 1A (ARID1A has emerged as a new tumor suppressor in which frequent somatic mutations have been identified in several types of human cancers. Although most ARID1A somatic mutations are frame-shift or nonsense mutations that contribute to mRNA decay and loss of protein expression, 5% of ARID1A mutations are in-frame insertions or deletions (indels that involve only a small stretch of peptides. Naturally occurring in-frame indel mutations provide unique and useful models to explore the biology and regulatory role of ARID1A. In this study, we analyzed indel mutations identified in gynecological cancers to determine how these mutations affect the tumor suppressor function of ARID1A. Our results demonstrate that all in-frame mutants analyzed lost their ability to inhibit cellular proliferation or activate transcription of CDKN1A, which encodes p21, a downstream effector of ARID1A. We also showed that ARID1A is a nucleocytoplasmic protein whose stability depends on its subcellular localization. Nuclear ARID1A is less stable than cytoplasmic ARID1A because ARID1A is rapidly degraded by the ubiquitin-proteasome system in the nucleus. In-frame deletions affecting the consensus nuclear export signal reduce steady-state protein levels of ARID1A. This defect in nuclear exportation leads to nuclear retention and subsequent degradation. Our findings delineate a mechanism underlying the regulation of ARID1A subcellular distribution and protein stability and suggest that targeting the nuclear ubiquitin-proteasome system can increase the amount of the ARID1A protein in the nucleus and restore its tumor suppressor functions.

  12. Intracellular delivery of potential therapeutic genes: prospects in cancer gene therapy.

    Science.gov (United States)

    Bakhtiar, Athirah; Sayyad, Mustak; Rosli, Rozita; Maruyama, Atsushi; Chowdhury, Ezharul H

    2014-01-01

    Conventional therapies for malignant cancer such as chemotherapy and radiotherapy are associated with poor survival rates owing to the development of cellular resistance to cancer drugs and the lack of targetability, resulting in unwanted adverse effects on healthy cells and necessitating the lowering of therapeutic dose with consequential lower efficacy of the treatment. Gene therapy employing different types of viral and non-viral carriers to transport gene(s) of interest and facilitating production of the desirable therapeutic protein(s) has tremendous prospects in cancer treatments due to the high-level of specificity in therapeutic action of the expressed protein(s) with diminished off-target effects, although cancer cell-specific delivery of transgene(s) still poses some challenges to be addressed. Depending on the potential therapeutic target genes, cancer gene therapy could be categorized into tumor suppressor gene replacement therapy, immune gene therapy and enzyme- or prodrug-based therapy. This review would shed light on the current progress of delivery of potentially therapeutic genes into various cancer cells in vitro and animal models utilizing a variety of viral and non-viral vectors.

  13. Spread of a new parasitic B chromosome variant is facilitated by high gene flow.

    Directory of Open Access Journals (Sweden)

    María Inmaculada Manrique-Poyato

    Full Text Available The B24 chromosome variant emerged several decades ago in a Spanish population of the grasshopper Eyprepocnemis plorans and is currently reaching adjacent populations. Here we report, for the first time, how a parasitic B chromosome (a strictly vertically transmitted parasite expands its geographical range aided by high gene flow in the host species. For six years we analyzed B frequency in several populations to the east and west of the original population and found extensive spatial variation, but only a slight temporal trend. The highest B24 frequency was found in its original population (Torrox and it decreased closer to both the eastern and the western populations. The analysis of Inter Simple Sequence Repeat (ISSR markers showed the existence of a low but significant degree of population subdivision, as well as significant isolation by distance (IBD. Pairwise Nem estimates suggested the existence of high gene flow between the four populations located in the Torrox area, with higher values towards the east. No significant barriers to gene flow were found among these four populations, and we conclude that high gene flow is facilitating B24 diffusion both eastward and westward, with minor role for B24 drive due to the arrival of drive suppressor genes which are also frequent in the donor population.

  14. Physical mapping of a commonly deleted region, the site of a candidate tumor suppressor gene, at 12q22 in human male germ cell tumors

    Energy Technology Data Exchange (ETDEWEB)

    Murty, V.V.V.S.; Bosl, G.J.; Chaganti, R.S.K. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [and others

    1996-08-01

    A candidate tumor suppressor gene (TSG) site at 12q22 characterized by a high frequency of loss of heterozygosity (LOH) and a homozygous deletion has previously (LOH) and a homozygous deletion has previously been reported in human male germ cell tumors (GCTs). In a detailed deletion mapping analysis of 67 normal-tumor DNAs utilizing 20 polymorphic markers mapped to 12q22-q24, we identified the limits of the minimal region of deletion at 12q22 between D12S377 (priximal) and D12S296 (distal). We have constructed a YAC contig map of a 3-cM region of this band between the proximal marker D12S101 and the distal marker D12S346, which contained the minimal region of deletion in GCTs. The map is composed of 53 overlapping YACs and 3 cosmids onto which 25 polymorphic and nonpolymorphic sequence-tagged sites (STSs) were placed in a unique order. The size of the minimal region of deletion was approximately 2 Mb from overlapping, nonchimeric YACs that spanned the region. We also developed a radiation hybrid (RH) map of the region between D12S101 and D12S346 containing 17 loci. The consensus order developed by RH mapping is in good agreement with the YAC STS-content map order. The RH map estimated the distance between D12S101 and D12S346 to be 246 cR{sub 8000} and the minimal region of deletion to be 141 cR{sub 8000}. In addition, four genes that were previously mapped to 12q22 have been excluded as candidate genes. The leads gained from the deletion mapping and physical maps should expedite the isolation and characterization of the TSG at 12q22. 35 refs., 4 figs., 2 tabs.

  15. Unique mutation portraits and frequent COL2A1 gene alteration in chondrosarcoma

    Science.gov (United States)

    Totoki, Yasushi; Yoshida, Akihiko; Hosoda, Fumie; Nakamura, Hiromi; Hama, Natsuko; Ogura, Koichi; Yoshida, Aki; Fujiwara, Tomohiro; Arai, Yasuhito; Toguchida, Junya; Tsuda, Hitoshi; Miyano, Satoru; Kawai, Akira

    2014-01-01

    Chondrosarcoma is the second most frequent malignant bone tumor. However, the etiological background of chondrosarcomagenesis remains largely unknown, along with details on molecular alterations and potential therapeutic targets. Massively parallel paired-end sequencing of whole genomes of 10 primary chondrosarcomas revealed that the process of accumulation of somatic mutations is homogeneous irrespective of the pathological subtype or the presence of IDH1 mutations, is unique among a range of cancer types, and shares significant commonalities with that of prostate cancer. Clusters of structural alterations localized within a single chromosome were observed in four cases. Combined with targeted resequencing of additional cartilaginous tumor cohorts, we identified somatic alterations of the COL2A1 gene, which encodes an essential extracellular matrix protein in chondroskeletal development, in 19.3% of chondrosarcoma and 31.7% of enchondroma cases. Epigenetic regulators (IDH1 and YEATS2) and an activin/BMP signal component (ACVR2A) were recurrently altered. Furthermore, a novel FN1-ACVR2A fusion transcript was observed in both chondrosarcoma and osteochondromatosis cases. With the characteristic accumulative process of somatic changes as a background, molecular defects in chondrogenesis and aberrant epigenetic control are primarily causative of both benign and malignant cartilaginous tumors. PMID:25024164

  16. Effect of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on the growth and radiotherapeutic sensitivity of human lymphoma cell lines

    International Nuclear Information System (INIS)

    Yu Zeyang; Fan Wo; Li Dongqing; Zhu Ran; Wang Yongqing; Wu Jinchang

    2008-01-01

    Objective: To explore the inhibitory effect and radiation sensitization of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on human lymphoma cell lines. Methods: Human lymphoma cell lines Raji and Daudi were treated with rAd-p53, radiation therapy and combined treatment, respectively. The cell growth inhibition was assessed by MTT. The p53 protein expression was detected by Western blotting, and p53 mRNA was detected by BT-PCB. Results: The MTT results showed that the inhibitory effect and radiosensitivity enhancement of rAd-p53 on human lymphoma cell lines were not obvious [Raji: (27.5±4.1)%; Daudi: (28.1±1.6)%]. The results of Western blotting and BT-PCB showed that extrinsic p53 protein and p53 mRNA were expressed to some degree, but not at high-level. In addition, the results didn't demonstrate obvious radiosensitivity enhancement. Conclusions: The role of inhibition and radiosensitivity enhancement of rAd-p53 was not significant on human lymphoma cell lines. (authors)

  17. Suppressor cells in transplantation tolerance. III. The role of antigen in the maintenance of transplantation tolerance

    International Nuclear Information System (INIS)

    Tutschka, P.J.; Hess, A.D.; Beschorner, W.E.; Santos, G.W.

    1982-01-01

    Suppressor cells, which in an alloantigen-specific manner inhibit proliferation of donor cells to host antigens in a mixed lymphocyte culture and adoptively transfer the suppression of graft-versus-host disease (GVHD), undergo a gradual clonal reduction in long-term, allogeneic, histoincompatible rat radiation chimeras until they can no longer be measured in an in vitro suppressor cell assay. When lymphohematopoietic cells from these chimeras are transferred into lethally irradiated secondary recipients of original donor strain, the suppressor cells, now in a target antigen-free environment, undergo a further clonal reduction. After parking for 120 days, the chimeric cells are specifically tolerant to original host antigens, but cannot adoptively transfer suppression of GVHD. When chimeric cells, parked for 120 days in secondary recipients of original donor strain, are stimulated with original host-type antigen repeatedly during or once at the end of the parking period, the suppressor cell clone is expanded, suppressor cells can be identified in vitro, and suppression of GVHD can adoptively be transferred to tertiary recipients

  18. The mouse small eye mutant, Del(2)Sey3H, which deletes the putative tumor suppressor region of the radiation-induced acute myeloid leukemia is susceptible to radiation

    International Nuclear Information System (INIS)

    Nitta, Yumiko; Yoshida, Kazuko; Tanaka, Kimio; Peters, Jo; Cattanach, Bruce M.

    2003-01-01

    Radiation-induced murine acute myeloid leukemia (AML) is characterized by the chromosome 2 deletions. Standing on the hypothesis that an AML suppressor gene would locate on the chromosome 2, a deletion-wide screen was performed on radiation-induced AMLs by the fluorescence in situ hybridization (FISH) method. The hemizugous deletion of the D2Mit15, a marker DNA at the 49.0cM region from the centromere, associated with the AMLs in 97 out of the 105 cases (92.4%). As the deletion region was close to the region of human WAGR syndrome (MIM194072), the mouse small eye mutants could be the animal model for radiation-induced AMLs. The mutant, Del(2)Sey3H (Sey3H) was found to delete around the 49.0cM region by the allelic loss mapping. The Sey3H showed high susceptibility to radiation to develop tumors including the myeloid leukemia with shorter latency. These finding support the existence of a putative tumor suppressor gene responsible for the radiation-leukemogenesis near the D2Mit15 region. (author)

  19. Cowpea mosaic virus RNA-1 acts as an amplicon whose effects can be counteracted by a RNA-2-encoded suppressor of silencing

    International Nuclear Information System (INIS)

    Liu Li; Grainger, Jef; Canizares, M. Carmen; Angell, Susan M.; Lomonossoff, George P.

    2004-01-01

    Lines of Nicotiana benthamiana transgenic for full-length copies of both Cowpea mosaic virus (CPMV) genomic RNAs, either singly or together, have been produced. Plants transgenic for both RNAs developed symptoms characteristic of a CPMV infection. When plants transgenic for RNA-1 were agro-inoculated with RNA-2, no infection developed and the plants were also resistant to challenge with CPMV. By contrast, plants transgenic for RNA-2 became infected when agro-inoculated with RNA-1 and were fully susceptible to CPMV infection. The resistance of RNA-1 transgenic plants was shown to be related to the ability of RNA-1 to self-replicate and act as an amplicon. The ability of transgenically expressed RNA-2 to counteract the amplicon effect suggested that it encodes a suppressor of posttranscriptional gene silencing (PTGS). By examining the ability of portions of RNA-2 to reverse PTGS in N. benthamiana, we have identified the small (S) coat protein as the CPMV RNA-2-encoded suppressor of PTGS

  20. Gene alterations in radiation-induced F344 rat lung tumors

    International Nuclear Information System (INIS)

    Kelly, G.; Hahn, F.F.

    1994-01-01

    The p53 tumor suppressor gene is frequently altered in all major histopathologic types of human lung tumors. Reported p53 mutations include base substitutions, allelic loss, rearrangements, and deletions. Point mutations resulting in base substitutions are clustered within a highly conserved region of the gene encoding exons 508, and mutations in this region substantially extend the half-life of the p53 protein. In addition to its prominent importance in lung carcinogenesis, the p53 gene plays a critical role in the cellular response to genetic damage caused by radiation. Specifically, the protein product of p53 induces a pause or block at the G 1 to S boundary of the cell cycle following radiation-caused DNA damage. This G 1 block may allow the cell time to repair the damaged DNA prior to replication. Cells lacking a functional p53 protein fail to pause for repair and consequently accumulate mutations in the genome at an accelerated rate. p53 has also been implicated as a controlling factor in apoptosis or in programmed cell death induced by DNA-damaging agents, such as ionizing radiation. The p53 gene is mutated in approximately 50% of squamous cell carcinomas from uranium miners who inhaled high doses of radon daughters. The purpose of the present study was to determine if a similar percentage of squamous cell carcinomas with p53 mutations developed in the lungs of rats exposed to aerosols of 239 PuO 2

  1. Novel Mutations in Synaptic Transmission Genes Suppress Neuronal Hyperexcitation in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Katherine A. McCulloch

    2017-07-01

    Full Text Available Acetylcholine (ACh receptors (AChR regulate neural circuit activity in multiple contexts. In humans, mutations in ionotropic acetylcholine receptor (iAChR genes can cause neurological disorders, including myasthenia gravis and epilepsy. In Caenorhabditis elegans, iAChRs play multiple roles in the locomotor circuit. The cholinergic motor neurons express an ACR-2-containing pentameric AChR (ACR-2R comprised of ACR-2, ACR-3, ACR-12, UNC-38, and UNC-63 subunits. A gain-of-function mutation in the non-α subunit gene acr-2 [acr-2(gf] causes defective locomotion as well as spontaneous convulsions. Previous studies of genetic suppressors of acr-2(gf have provided insights into ACR-2R composition and assembly. Here, to further understand how the ACR-2R regulates neuronal activity, we expanded the suppressor screen for acr-2(gf-induced convulsions. The majority of these suppressor mutations affect genes that play critical roles in synaptic transmission, including two novel mutations in the vesicular ACh transporter unc-17. In addition, we identified a role for a conserved major facilitator superfamily domain (MFSD protein, mfsd-6, in regulating neural circuit activity. We further defined a role for the sphingosine (SPH kinase (Sphk sphk-1 in cholinergic neuron activity, independent of previously known signaling pathways. Overall, the genes identified in our study suggest that optimal modulation of synaptic activity is balanced by the differential activities of multiple pathways, and the novel alleles provide valuable reagents to further dissect neuronal mechanisms regulating the locomotor circuit.

  2. Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context.

    Science.gov (United States)

    Chiu, Hua-Sheng; Somvanshi, Sonal; Patel, Ektaben; Chen, Ting-Wen; Singh, Vivek P; Zorman, Barry; Patil, Sagar L; Pan, Yinghong; Chatterjee, Sujash S; Sood, Anil K; Gunaratne, Preethi H; Sumazin, Pavel

    2018-04-03

    Long noncoding RNAs (lncRNAs) are commonly dysregulated in tumors, but only a handful are known to play pathophysiological roles in cancer. We inferred lncRNAs that dysregulate cancer pathways, oncogenes, and tumor suppressors (cancer genes) by modeling their effects on the activity of transcription factors, RNA-binding proteins, and microRNAs in 5,185 TCGA tumors and 1,019 ENCODE assays. Our predictions included hundreds of candidate onco- and tumor-suppressor lncRNAs (cancer lncRNAs) whose somatic alterations account for the dysregulation of dozens of cancer genes and pathways in each of 14 tumor contexts. To demonstrate proof of concept, we showed that perturbations targeting OIP5-AS1 (an inferred tumor suppressor) and TUG1 and WT1-AS (inferred onco-lncRNAs) dysregulated cancer genes and altered proliferation of breast and gynecologic cancer cells. Our analysis indicates that, although most lncRNAs are dysregulated in a tumor-specific manner, some, including OIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergistically dysregulate cancer pathways in multiple tumor contexts. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Chromosomal Aberrations in Canine Gliomas Define Candidate Genes and Common Pathways in Dogs and Humans

    Science.gov (United States)

    York, Dan; Higgins, Robert J.; LeCouteur, Richard A.; Joshi, Nikhil; Bannasch, Danika

    2016-01-01

    Spontaneous gliomas in dogs occur at a frequency similar to that in humans and may provide a translational model for therapeutic development and comparative biological investigations. Copy number alterations in 38 canine gliomas, including diffuse astrocytomas, glioblastomas, oligodendrogliomas, and mixed oligoastrocytomas, were defined using an Illumina 170K single nucleotide polymorphism array. Highly recurrent alterations were seen in up to 85% of some tumor types, most notably involving chromosomes 13, 22, and 38, and gliomas clustered into 2 major groups consisting of high-grade IV astrocytomas, or oligodendrogliomas and other tumors. Tumor types were characterized by specific broad and focal chromosomal events including focal loss of the INK4A/B locus in glioblastoma and loss of the RB1 gene and amplification of the PDGFRA gene in oligodendrogliomas. Genes associated with the 3 critical pathways in human high-grade gliomas (TP53, RB1, and RTK/RAS/PI3K) were frequently associated with canine aberrations. Analysis of oligodendrogliomas revealed regions of chromosomal losses syntenic to human 1p involving tumor suppressor genes, such as CDKN2C, as well as genes associated with apoptosis, autophagy, and response to chemotherapy and radiation. Analysis of high frequency chromosomal aberrations with respect to human orthologues may provide insight into both novel and common pathways in gliomagenesis and response to therapy. PMID:27251041

  4. Sulforaphane Reverses the Expression of Various Tumor Suppressor Genes by Targeting DNMT3B and HDAC1 in Human Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Munawwar Ali Khan

    2015-01-01

    Full Text Available Sulforaphane (SFN may hinder carcinogenesis by altering epigenetic events in the cells; however, its molecular mechanisms are unclear. The present study investigates the role of SFN in modifying epigenetic events in human cervical cancer cells, HeLa. HeLa cells were treated with SFN (2.5 µM for a period of 0, 24, 48, and 72 hours for all experiments. After treatment, expressions of DNMT3B, HDAC1, RARβ, CDH1, DAPK1, and GSTP1 were studied using RT-PCR while promoter DNA methylation of tumor suppressor genes (TSGs was studied using MS-PCR. Inhibition assays of DNA methyl transferases (DNMTs and histone deacetylases (HDACs were performed at varying time points. Molecular modeling and docking studies were performed to explore the possible interaction of SFN with HDAC1 and DNMT3B. Time-dependent exposure to SFN decreases the expression of DNMT3B and HDAC1 and significantly reduces the enzymatic activity of DNMTs and HDACs. Molecular modeling data suggests that SFN may interact directly with DNMT3B and HDAC1 which may explain the inhibitory action of SFN. Interestingly, time-dependent reactivation of the studied TSGs via reversal of methylation in SFN treated cells correlates well with its impact on the epigenetic alterations accumulated during cancer development. Thus, SFN may have significant implications for epigenetic based therapy.

  5. Frequent adaptive immune responses against arginase-1

    DEFF Research Database (Denmark)

    Martinenaite, Evelina; Mortensen, Rasmus Erik Johansson; Hansen, Morten

    2018-01-01

    The enzyme arginase-1 reduces the availability of arginine to tumor-infiltrating immune cells, thus reducing T-cell functionality in the tumor milieu. Arginase-1 is expressed by some cancer cells and by immune inhibitory cells, such as myeloid-derived suppressor cells (MDSCs) and tumor-associated...

  6. Effect of hemopoietic microenvironment on splenic suppressor macrophages in congenitally anemic mice of genotype Sl/Sld

    International Nuclear Information System (INIS)

    Shibata, Y.; Volkman, A.

    1985-01-01

    Mechanisms underlying mononuclear phagocyte specialization are being probed by studying suppressor macrophages (M phi) as a reference population in mouse models with impaired blood monocyte formation. Splenic suppressor M phi, defined by PGE-mediated inhibition of Con A-induced T lymphocyte proliferation are induced by the i.p. administration of Corynebacterium parvum (CP). Mice severely depleted of bone marrow and blood monocytes by treatment with 89Sr fail to show this suppressor M phi response to CP, although M phi-forming stem cells, assessed as splenic M-CFC in vitro, are increased 20-fold. These observations suggest that radiosensitive bone marrow stem cells are necessary for the generation of both suppressor M phi and monocytes and that one such stem cell may be common to both types of mononuclear phagocytes. This notion was explored further by employing congenitally anemic mice of the genotype S1/S1d in which the hemopoietic microenvironment is genetically defective and thus unable to support the proliferation, differentiation, and function of stem cells. The congenital defect was found to be additionally expressed in the S1/S1d mouse by a monocytopenia of less than 10% of the values in normal congenic littermate controls and by the failure of splenic M-CFC to increase in response to CP. PGE-producing suppressor M phi expressing Fc gamma 2b receptors, however, were induced by CP in S1/S1d mice with no significant diminution of suppressor activity. These data establish the fact that significant impairment of the formation of monocytes is part of the overall hemopoietic defect in S1/S1d mice. PGE-producing suppressor M phi, however, were inducible at normal functional levels in the presence of a profound monocytopenia, and therefore appear to be independent of the mechanisms that regulate blood monocyte formation

  7. Combining Oncolytic Virotherapy with p53 Tumor Suppressor Gene Therapy

    Directory of Open Access Journals (Sweden)

    Christian Bressy

    2017-06-01

    Full Text Available Oncolytic virus (OV therapy utilizes replication-competent viruses to kill cancer cells, leaving non-malignant cells unharmed. With the first U.S. Food and Drug Administration-approved OV, dozens of clinical trials ongoing, and an abundance of translational research in the field, OV therapy is poised to be one of the leading treatments for cancer. A number of recombinant OVs expressing a transgene for p53 (TP53 or another p53 family member (TP63 or TP73 were engineered with the goal of generating more potent OVs that function synergistically with host immunity and/or other therapies to reduce or eliminate tumor burden. Such transgenes have proven effective at improving OV therapies, and basic research has shown mechanisms of p53-mediated enhancement of OV therapy, provided optimized p53 transgenes, explored drug-OV combinational treatments, and challenged canonical roles for p53 in virus-host interactions and tumor suppression. This review summarizes studies combining p53 gene therapy with replication-competent OV therapy, reviews preclinical and clinical studies with replication-deficient gene therapy vectors expressing p53 transgene, examines how wild-type p53 and p53 modifications affect OV replication and anti-tumor effects of OV therapy, and explores future directions for rational design of OV therapy combined with p53 gene therapy.

  8. Microcell-mediated chromosome transfer identifies EPB41L3 as a functional suppressor of epithelial ovarian cancers

    DEFF Research Database (Denmark)

    Dafou, Dimitra; Grun, Barbara; Sinclair, John

    2010-01-01

    lines. Using immunohistochemistry, 66% of 794 invasive ovarian tumors showed no EPB41L3 expression compared with only 24% of benign ovarian tumors and 0% of normal ovarian epithelial tissues. EPB41L3 was extensively methylated in ovarian cancer cell lines and primary ovarian tumors compared with normal...... (erythrocyte membrane protein band 4.1-like 3, alternative names DAL-1 and 4.1B) was a candidate ovarian cancer-suppressor gene. Immunoblot analysis showed that EPB41L3 was activated in TOV21G(+18) hybrids, expressed in normal ovarian epithelial cell lines, but was absent in 15 (78%) of 19 ovarian cancer cell...... tissues (P = .00004), suggesting this may be the mechanism of gene inactivation in ovarian cancers. Constitutive reexpression of EPB41L3 in a three-dimensional multicellular spheroid model of ovarian cancer caused significant growth suppression and induced apoptosis. Transmission and scanning electron...

  9. LncRNA TUG1 acts as a tumor suppressor in human glioma by promoting cell apoptosis.

    Science.gov (United States)

    Li, Jun; Zhang, Meng; An, Gang; Ma, Qingfang

    2016-03-01

    Previous studies have revealed multiple functional roles of long non-coding RNA taurine upregulated gene 1 in different types of malignant tumors, except for human glioma. Here, it was designed to study the potential function of taurine upregulated gene 1 in glioma pathogenesis focusing on its regulation on cell apoptosis. The expression of taurine upregulated gene 1 in glioma tissues was detected by quantitative RT-PCR and compared with that in adjacent normal tissues. Further correlation analysis was conducted to show the relationship between taurine upregulated gene 1 expression and different clinicopathologic parameters. Functional studies were performed to investigate the influence of taurine upregulated gene 1 on apoptosis and cell proliferation by using Annexin V/PI staining and cell counting kit-8 assays, respectively. And, caspase activation and Bcl-2 expression were analyzed to explore taurine upregulated gene 1-induced mechanism. taurine upregulated gene 1 expression was significantly inhibited in glioma and showed significant correlation with WHO Grade, tumor size and overall survival. Further experiments revealed that the dysregulation of taurine upregulated gene 1 affected the apoptosis and cell proliferation of glioma cells. Moreover, taurine upregulated gene 1 could induce the activation of caspase-3 and-9, with inhibited expression of Bcl-2, implying the mechanism in taurine upregulated gene 1-induced apoptosis. taurine upregulated gene 1 promoted cell apoptosis of glioma cells by activating caspase-3 and -9-mediated intrinsic pathways and inhibiting Bcl-2-mediated anti-apoptotic pathways, acting as a tumor suppressor in human glioma. This study provided new insights for the function of taurine upregulated gene 1 in cancer biology, and suggested a potent application of taurine upregulated gene 1 overexpression for glioma therapy. © 2016 by the Society for Experimental Biology and Medicine.

  10. Frequent alterations in cytoskeleton remodelling genes in primary and metastatic lung adenocarcinomas

    DEFF Research Database (Denmark)

    Wu, Kui; Zhang, Xin; Li, Fuqiang

    2015-01-01

    significantly mutated genes are identified, including the most commonly mutated gene TP53 and novel mutation targets such as RHPN2, GLI3 and MRC2. TP53 mutations are furthermore significantly enriched in tumours from patients harbouring metastases. Genes regulating cytoskeleton remodelling processes are also...

  11. Identification of epigenetically regulated genes that predict patient outcome in neuroblastoma

    International Nuclear Information System (INIS)

    Carén, Helena; Djos, Anna; Nethander, Maria; Sjöberg, Rose-Marie; Kogner, Per; Enström, Camilla; Nilsson, Staffan; Martinsson, Tommy

    2011-01-01

    Epigenetic mechanisms such as DNA methylation and histone modifications are important regulators of gene expression and are frequently involved in silencing tumor suppressor genes. In order to identify genes that are epigenetically regulated in neuroblastoma tumors, we treated four neuroblastoma cell lines with the demethylating agent 5-Aza-2'-deoxycytidine (5-Aza-dC) either separately or in conjunction with the histone deacetylase inhibitor trichostatin A (TSA). Expression was analyzed using whole-genome expression arrays to identify genes activated by the treatment. These data were then combined with data from genome-wide DNA methylation arrays to identify candidate genes silenced in neuroblastoma due to DNA methylation. We present eight genes (KRT19, PRKCDBP, SCNN1A, POU2F2, TGFBI, COL1A2, DHRS3 and DUSP23) that are methylated in neuroblastoma, most of them not previously reported as such, some of which also distinguish between biological subsets of neuroblastoma tumors. Differential methylation was observed for the genes SCNN1A (p < 0.001), PRKCDBP (p < 0.001) and KRT19 (p < 0.01). Among these, the mRNA expression of KRT19 and PRKCDBP was significantly lower in patients that have died from the disease compared with patients with no evidence of disease (fold change -8.3, p = 0.01 for KRT19 and fold change -2.4, p = 0.04 for PRKCDBP). In our study, a low methylation frequency of SCNN1A, PRKCDBP and KRT19 is significantly associated with favorable outcome in neuroblastoma. It is likely that analysis of specific DNA methylation will be one of several methods in future patient therapy stratification protocols for treatment of childhood neuroblastomas

  12. Dancing together and separate again: gymnosperms exhibit frequent changes of fundamental 5S and 35S rRNA gene (rDNA) organisation.

    Science.gov (United States)

    Garcia, S; Kovařík, A

    2013-07-01

    In higher eukaryotes, the 5S rRNA genes occur in tandem units and are arranged either separately (S-type arrangement) or linked to other repeated genes, in most cases to rDNA locus encoding 18S-5.8S-26S genes (L-type arrangement). Here we used Southern blot hybridisation, PCR and sequencing approaches to analyse genomic organisation of rRNA genes in all large gymnosperm groups, including Coniferales, Ginkgoales, Gnetales and Cycadales. The data are provided for 27 species (21 genera). The 5S units linked to the 35S rDNA units occur in some but not all Gnetales, Coniferales and in Ginkgo (∼30% of the species analysed), while the remaining exhibit separate organisation. The linked 5S rRNA genes may occur as single-copy insertions or as short tandems embedded in the 26S-18S rDNA intergenic spacer (IGS). The 5S transcript may be encoded by the same (Ginkgo, Ephedra) or opposite (Podocarpus) DNA strand as the 18S-5.8S-26S genes. In addition, pseudogenised 5S copies were also found in some IGS types. Both L- and S-type units have been largely homogenised across the genomes. Phylogenetic relationships based on the comparison of 5S coding sequences suggest that the 5S genes independently inserted IGS at least three times in the course of gymnosperm evolution. Frequent transpositions and rearrangements of basic units indicate relatively relaxed selection pressures imposed on genomic organisation of 5S genes in plants.

  13. Recurrent APC gene mutations in Polish FAP families

    Directory of Open Access Journals (Sweden)

    Pławski Andrzej

    2007-12-01

    Full Text Available Abstract The molecular diagnostics of genetically conditioned disorders is based on the identification of the mutations in the predisposing genes. Hereditary cancer disorders of the gastrointestinal tracts are caused by mutations of the tumour suppressor genes or the DNA repair genes. Occurrence of recurrent mutation allows improvement of molecular diagnostics. The mutation spectrum in the genes causing hereditary forms of colorectal cancers in the Polish population was previously described. In the present work an estimation of the frequency of the recurrent mutations of the APC gene was performed. Eight types of mutations occurred in 19.4% of our FAP families and these constitute 43% of all Polish diagnosed families.

  14. Suppressors of RNA silencing encoded by tomato leaf curl ...

    Indian Academy of Sciences (India)

    2013-01-06

    Jan 6, 2013 ... Virus encoded RNA-silencing suppressors (RSSs) are the key components evolved by the viruses to ... severe disease symptom in the host (Briddon et al. ..... Voinnet O 2001 RNA silencing as a plant immune system against.

  15. Mutational analysis of FLASH and PTPN13 genes in colorectal carcinomas.

    Science.gov (United States)

    Jeong, Eun Goo; Lee, Sung Hak; Yoo, Nam Jin; Lee, Sug Hyung

    2008-01-01

    The Fas-Fas ligand system is considered a major pathway for induction of apoptosis in cells and tissues. FLASH was identified as a pro-apoptotic protein that transmits apoptosis signal during Fas-mediated apoptosis. PTPN13 interacts with Fas and functions as both suppressor and inducer of Fas-mediated apoptosis. There are polyadenine tracts in both FLASH (A8 and A9 in exon 8) and PTPN13 (A8 in exon 7) genes that could be frameshift mutation targets in colorectal carcinomas. Because genes encoding proteins in Fas-mediated apoptosis frequently harbor somatic mutations in cancers, we explored the possibility as to whether mutations of FLASH and PTPN13 are a feature of colorectal carcinomas. We analysed human FLASH in exon 8 and PTPN13 in exon 7 for the detection of somatic mutations in 103 colorectal carcinomas by a polymerase chain reaction (PCR)- based single-strand conformation polymorphism (SSCP). We detected two mutations in FLASH gene, but none in PTPN13 gene. However, the two mutations were not frameshift (deletion or insertion) mutations in the polyadenine tracts of FLASH. The two mutations consisted of a deletion mutation (c.3734-3737delAGAA) and a missense mutation (c.3703A>C). These data indicate that frameshift mutation in the polyadenine tracts in both FLASH and PTPN13 genes is rare in colorectal carcinomas. Also, the data suggest that both FLASH and PTPN13 mutations in the polyadenine tracts may not have a crucial role in the pathogenesis of colorectal carcinomas.

  16. CT-guided intratumoral gene therapy in non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Kauczor, H.U.; Heussel, C.P.; Thelen, M.; Schuler, M.; Huber, C.; Weymarn, A. von; Bongartz, G.; Rochlitz, C.

    1999-01-01

    The objective of this study was to prove the principle of CT-guided gene therapy by intratumoral injection of a tumor suppressor gene as an alternative treatment approach of incurable non-small-cell lung cancer. In a prospective clinical phase I trial six patients with non-small-cell lung cancer and a mutation of the tumor suppressor gene p53 were treated by CT-guided intratumoral gene therapy. Ten milliliters of a vector solution (replication-defective adenovirus with complete wild-type p53 cDNA) were injected under CT guidance. In four cases the vector solution was completely applied to the tumor center, whereas in two cases 2 ml aliquots were injected into different tumor areas. For the procedure the scan room had been approved as a biosafety cabinet. Gene transfer was assessed by reverse transcription and polymerase chain reaction in biopsy specimens obtained under CT guidance 24-48 h after therapy. Potential therapeutic efficacy was evaluated on day 28 after treatment using spiral CT. The CT-guided gene therapy was easily performed in all six patients without intervention-related complications. Besides flu-like symptoms, no significant adverse effects of gene therapy were noted. Three of the four patients with central injection exhibited gene transfer in the posttreatment biopsy. Gene transfer could not be proven in the two patients with multiple 2 ml injections. After 28 days, four of the six patients showed stable disease at the treated tumor site, whereas other tumor manifestations progressed. Computed tomography-guided injections are an adequate and easy-to-perform procedure for intratumoral gene therapy. (orig.)

  17. High frequency of p 16 promoter methylation in non-small cell lung carcinomas from Chile

    Directory of Open Access Journals (Sweden)

    LEDA M GUZMAN

    2007-01-01

    Full Text Available The inactivation of tumour suppressor genes by aberrant methylation of promoter regions has been described as a frequent event in neoplasia development, including lung cancer. The p16 gene is a tumour suppressor gene involved in the regulation of cell cycle progression that has been reported to be inactivated by promoter methylation in lung carcinomas at variable frequencies around the world in a smoking habit dependent manner. The purpose of this study was to investigate the methylation status of the promoter region of the p16 gene in 74 non-small cell lung carcinomas from Chile. The frequency of p16 gene inactivation by promoter methylation was determined as 79.7% (59/74. When we considered histological type, we observed that p16 promoter methylation was significantly higher in squamous cell carcinomas (30/33, 91% compared with adenocarcinomas (21/30, 70% (p=0.029. In addition, no association between p16 promoter methylation and gender, age or smoking habit was found (p=0.202, 0.202 and 0.147 respectively. Our results suggest that p16 promoter hypermethylation is a very frequent event in non-small cell lung carcinomas from Chile and could be smoking habit-independent

  18. DA-Raf, a dominant-negative antagonist of the Ras-ERK pathway, is a putative tumor suppressor.

    Science.gov (United States)

    Kanno, Emiri; Kawasaki, Osamu; Takahashi, Kazuya; Takano, Kazunori; Endo, Takeshi

    2018-01-01

    Activating mutations of RAS genes, particularly KRAS, are detected with high frequency in human tumors. Mutated Ras proteins constitutively activate the ERK pathway (Raf-MEK-ERK phosphorylation cascade), leading to cellular transformation and tumorigenesis. DA-Raf1 (DA-Raf) is a splicing variant of A-Raf and contains the Ras-binding domain (RBD) but lacks the kinase domain. Accordingly, DA-Raf antagonizes the Ras-ERK pathway in a dominant-negative fashion and suppresses constitutively activated K-Ras-induced cellular transformation. Thus, we have addressed whether DA-Raf serves as a tumor suppressor of Ras-induced tumorigenesis. DA-Raf(R52Q), which is generated from a single nucleotide polymorphism (SNP) in the RBD, and DA-Raf(R52W), a mutant detected in a lung cancer, neither bound to active K-Ras nor interfered with the activation of the ERK pathway. They were incapable of suppressing activated K-Ras-induced cellular transformation and tumorigenesis in mice, in which K-Ras-transformed cells were transplanted. Furthermore, although DA-Raf was highly expressed in lung alveolar epithelial type 2 (AE2) cells, its expression was silenced in AE2-derived lung adenocarcinoma cell lines with oncogenic KRAS mutations. These results suggest that DA-Raf represents a tumor suppressor protein against Ras-induced tumorigenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Molecular cloning and chromosome mapping of the human gene encoding protein phosphotyrosyl phosphatase 1B

    International Nuclear Information System (INIS)

    Brown-Shimer, S.; Johnson, K.A.; Bruskin, A.; Green, N.R.; Hill, D.E.; Lawrence, J.B.; Johnson, C.

    1990-01-01

    The inactivation of growth suppressor genes appears to play a major role in the malignant process. To assess whether protein phosphotyrosyl phosphatases function as growth suppressors, the authors have isolated a cDNA clone encoding human protein phosphotyrosyl phosphatase 1B for structural and functional characterization. The translation product deduced from the 1,305-nucleotide open reading frame predicts a protein containing 435 amino acids and having a molecular mass of 49,966 Da. The amino-terminal 321 amino acids deduced from the cDNA sequence are identical to the empirically determined sequence of protein phosphotyrosyl phosphatase 1B. A genomic clone has been isolated and used in an in situ hybridization to banded metaphase chromosomes to determine that the gene encoding protein phosphotyrosyl phosphatase 1B maps as a single-copy gene to the long arm of chromosome 20 in the region q13.1-q13.2

  20. MMS sensitivity of all amino acid-requiring mutants in aspergillus and its suppression by mutations in a single gene.

    Science.gov (United States)

    Käfer, E

    1987-04-01

    All available amino acid-requiring mutants of Aspergillus nidulans were found to be hypersensitive to MMS (methyl methanesulfonate) to various degrees. On MMS media, secondary mutations could be selected which suppress this MMS sensitivity but do not affect the requirement. Many such mutations were analyzed and found to be alleles of one gene, smsA (= suppressor of MMS sensitivity), which mapped distal on the right arm of chromosome V. This gene is more likely to be involved in general regulation of amino acid biosynthesis than MMS uptake, since a variety of pathway interactions were clearly modified by smsA suppressors in the absence of MMS.

  1. Geographical Distribution of the Most Frequent Mutations of Familial Mediterranean fever in the World

    Directory of Open Access Journals (Sweden)

    Soraya Hadi

    2016-09-01

    Full Text Available Background and objectives: Familial Mediterranean Fever (FMF is an autosomal recessive disease. Generally, the Mediterranean basin is the region where the first cases of FMF have been identified. The gene responsible for FMF is gene MEFV. Disease occurs due to mutations in the gene MEFV. Our aim was to determine the geographical distribution of the most frequent mutations in Familial Mediterranean Fever Disease in the world. Material and Methods: In this study, databases including Google Scholar, PubMed, Medline, Ovid, IranMedex, Irandoc, SID, Magiran and published papers were searched with no limitation in time. Then, all collected studies without any limitation were assessed to determine relevant studies. At the end, world map of the most frequent mutations of FMF was generated by Geographical Information System (GIS software. Results: Although more than 290 mutations of the MEFV gene have been described, only four mutations (M694V, M694I, V726A, and E148Q were prevalent among patients with FMF. Conclusion: The most frequent mutation associated with FMF mutation is M694V all over the world. E148Q mutation was found to be with mild clinical relevance.

  2. Long term effect of curcumin in restoration of tumour suppressor p53 and phase-II antioxidant enzymes via activation of Nrf2 signalling and modulation of inflammation in prevention of cancer.

    Directory of Open Access Journals (Sweden)

    Laxmidhar Das

    Full Text Available Inhibition of carcinogenesis may be a consequence of attenuation of oxidative stress via activation of antioxidant defence system, restoration and stabilization of tumour suppressor proteins along with modulation of inflammatory mediators. Previously we have delineated significant role of curcumin during its long term effect in regulation of glycolytic pathway and angiogenesis, which in turn results in prevention of cancer via modulation of stress activated genes. Present study was designed to investigate long term effect of curcumin in regulation of Nrf2 mediated phase-II antioxidant enzymes, tumour suppressor p53 and inflammation under oxidative tumour microenvironment in liver of T-cell lymphoma bearing mice. Inhibition of Nrf2 signalling observed during lymphoma progression, resulted in down regulation of phase II antioxidant enzymes, p53 as well as activation of inflammatory signals. Curcumin potentiated significant increase in Nrf2 activation. It restored activity of phase-II antioxidant enzymes like GST, GR, NQO1, and tumour suppressor p53 level. In addition, curcumin modulated inflammation via upregulation of TGF-β and reciprocal regulation of iNOS and COX2. The study suggests that during long term effect, curcumin leads to prevention of cancer by inducing phase-II antioxidant enzymes via activation of Nrf2 signalling, restoration of tumour suppressor p53 and modulation of inflammatory mediators like iNOS and COX2 in liver of lymphoma bearing mice.

  3. MicroRNA-218 functions as a tumor suppressor in lung cancer by targeting IL-6/STAT3 and negatively correlates with poor prognosis.

    Science.gov (United States)

    Yang, Yan; Ding, Lili; Hu, Qun; Xia, Jia; Sun, Junjie; Wang, Xudong; Xiong, Hua; Gurbani, Deepak; Li, Lianbo; Liu, Yan; Liu, Aiguo

    2017-08-22

    Aberrant expression of microRNAs in different human cancer types has been widely reported. MiR-218 acts as a tumor suppressor in diverse human cancer types impacting regulation of multiple genes in oncogenic pathways. Here, we evaluated the expression and function of miR-218 in human lung cancer and ALDH positive lung cancer cells to understand the potential mechanisms responsible for disease pathology. Also, the association between its host genes and the target genes could be useful towards the better understanding of prognosis in clinical settings. Publicly-available data from The Cancer Genome Atlas (TCGA) was mined to compare the levels of miR-218 and its host gene SLIT2/3 between lung cancer tissues and normal lung tissues. Transfection of miR-218 to investigate its function in lung cancer cells was done and in vivo effects were determined using miR-218 expressing lentiviruses. Aldefluor assay and Flow cytometry was used to quantify and enrich ALDH positive lung cancer cells. Levels of miR-218, IL-6R, JAK3 and phosphorylated STAT3 were compared in ALDH1A1 positive and ALDH1A1 negative cells. Overexpression of miR-218 in ALDH positive cells was carried to test the survival by tumorsphere culture. Finally, utilizing TCGA data we studied the association of target genes of miR-218 with the prognosis of lung cancer. We observed that the expression of miR-218 was significantly down-regulated in lung cancer tissues compared to normal lung tissues. Overexpression of miR-218 decreased cell proliferation, invasion, colony formation, and tumor sphere formation in vitro and repressed tumor growth in vivo. We further found that miR-218 negatively regulated IL-6 receptor and JAK3 gene expression by directly targeting the 3'-UTR of their mRNAs. In addition, the levels of both miR-218 host genes and the components of IL-6/STAT3 pathway correlated with prognosis of lung cancer patients. MiR-218 acts as a tumor suppressor in lung cancer via IL-6/STAT3 signaling pathway

  4. Abnormalities in structure and expression of the retinoblastoma gene in small cell lung cancer cell lines and xenografts in nude mice

    DEFF Research Database (Denmark)

    Rygaard, K; Sorenson, G D; Pettengill, O S

    1990-01-01

    The putative retinoblastoma gene (Rb) is a tumor suppressor gene which is believed to cause retinoblastomas when both alleles are inactivated, leading to lack of the encoded Mr 110,000-116,000 phosphoprotein. Inactivation of the Rb gene has also been found in several other tumor types, including...

  5. Targeted massively parallel sequencing of angiosarcomas reveals frequent activation of the mitogen activated protein kinase pathway

    Science.gov (United States)

    Murali, Rajmohan; Chandramohan, Raghu; Möller, Inga; Scholz, Simone L.; Berger, Michael; Huberman, Kety; Viale, Agnes; Pirun, Mono; Socci, Nicholas D.; Bouvier, Nancy; Bauer, Sebastian; Artl, Monika; Schilling, Bastian; Schimming, Tobias; Sucker, Antje; Schwindenhammer, Benjamin; Grabellus, Florian; Speicher, Michael R.; Schaller, Jörg; Hillen, Uwe; Schadendorf, Dirk; Mentzel, Thomas; Cheng, Donavan T.; Wiesner, Thomas; Griewank, Klaus G.

    2015-01-01

    Angiosarcomas are rare malignant mesenchymal tumors of endothelial differentiation. The clinical behavior is usually aggressive and the prognosis for patients with advanced disease is poor with no effective therapies. The genetic bases of these tumors have been partially revealed in recent studies reporting genetic alterations such as amplifications of MYC (primarily in radiation-associated angiosarcomas), inactivating mutations in PTPRB and R707Q hotspot mutations of PLCG1. Here, we performed a comprehensive genomic analysis of 34 angiosarcomas using a clinically-approved, hybridization-based targeted next-generation sequencing assay for 341 well-established oncogenes and tumor suppressor genes. Over half of the angiosarcomas (n = 18, 53%) harbored genetic alterations affecting the MAPK pathway, involving mutations in KRAS, HRAS, NRAS, BRAF, MAPK1 and NF1, or amplifications in MAPK1/CRKL, CRAF or BRAF. The most frequently detected genetic aberrations were mutations in TP53 in 12 tumors (35%) and losses of CDKN2A in 9 tumors (26%). MYC amplifications were generally mutually exclusive of TP53 alterations and CDKN2A loss and were identified in 8 tumors (24%), most of which (n = 7, 88%) arose post-irradiation. Previously reported mutations in PTPRB (n = 10, 29%) and one (3%) PLCG1 R707Q mutation were also identified. Our results demonstrate that angiosarcomas are a genetically heterogeneous group of tumors, harboring a wide range of genetic alterations. The high frequency of genetic events affecting the MAPK pathway suggests that targeted therapies inhibiting MAPK signaling may be promising therapeutic avenues in patients with advanced angiosarcomas. PMID:26440310

  6. Transonic Performance Characteristics of Several Jet Noise Suppressors

    Science.gov (United States)

    Schmeer, James W.; Salters, Leland B., Jr.; Cassetti, Marlowe D.

    1960-01-01

    An investigation of the transonic performance characteristics of several noise-suppressor configurations has been conducted in the Langley 16-foot transonic tunnel. The models were tested statically and over a Mach number range from 0.70 to 1.05 at an angle of attack of 0 deg. The primary jet total-pressure ratio was varied from 1.0 (jet off) to about 4.5. The effect of secondary air flow on the performance of two of the configurations was investigated. A hydrogen peroxide turbojet-engine simulator was used to supply the hot-jet exhaust. An 8-lobe afterbody with centerbody, short shroud, and secondary air had the highest thrust-minus-drag coefficients of the six noise-suppressor configurations tested. The 12-tube and 12-lobe afterbodies had the lowest internal losses. The presence of an ejector shroud partially shields the external pressure distribution of the 8-lobe after-body from the influence of the primary jet. A ring-airfoil shroud increased the static thrust of the annular nozzle but generally decreased the thrust minus drag at transonic Mach numbers.

  7. Genetic analysis of suppressors of the PF10 mutation in Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Dutcher, S.K.; Gibbons, W.; Inwood, W.B.

    1988-01-01

    A mutation at the PF10 locus of the unicellular green alga Chlamydomonas reinhardtii leads to abnormal cell motility. The asymmetric form of the ciliary beat stroke characteristic of wild-type flagella is modified by this mutation to a nearly symmetric beat. We report here that this abnormal motility is a conditional phenotype that depends on light intensity. In the absence of light or under low light intensities, the motility is more severely impaired than at higher light intensities. By UV mutagenesis we obtained 11 intragenic and 70 extragenic strains that show reversion of the pf10 motility phenotype observed in low light. The intragenic events reverted the motility phenotype of the pf10 mutation completely. The extragenic events define at least seven suppressor loci; these map to linkage groups IV, VII, IX, XI, XII and XVII. Suppressor mutations at two of the seven loci (LIS1 and LIS2) require light for their suppressor activity. Forty-eight of the 70 extragenic suppressors were examined in heterozygous diploid cells; 47 of these mutants were recessive to the wild-type allele and one mutant (bop5-1) was dominant to the wild-type allele. Complementation analysis of the 47 recessive mutants showed unusual patterns. Most mutants within a recombinationally defined group failed to complement one another, although there were pairs that showed intra-allelic complementation. Additionally, some of the mutants at each recombinationally defined locus failed to complement mutants at other loci. They define dominant enhancers of one another

  8. Concanavalin A-induced and spontaneous suppressor cell activities in peripheral blood lymphocytes and spleen cells from gastric cancer patients.

    Science.gov (United States)

    Toge, T; Hamamoto, S; Itagaki, E; Yajima, K; Tanada, M; Nakane, H; Kohno, H; Nakanishi, K; Hattori, T

    1983-11-01

    In 173 gastric cancer patients, activities of Concanavalin-A-induced suppressor cells (Con-AS) and spontaneous suppressor cells (SpS) in peripheral blood lymphocytes (PBL), splenic vein lymphocytes (SVL), and spleen cells (SCs) were investigated. Suppressions by Con-AS in PBL were significantly effective in patients of Stages III and IV, while suppressions by SpS were effective in patients with recurrent tumors. Thus, in PBLs of cancer patients, suppressor precursors, which are considered to be activated in vitro by Concanavalin-A, seemed to appear with the advances of the disease, and SpS activities, which could be already activated in vivo, seemed to increase in the terminal stage. In SCs, increased activities of Con-AS, but normal activities of SpS, were observed, and these suppressor-cell populations consisted of glass nonadherent cells. Suppressor activities of SCs would be due to suppressor T-cells, not to other types of cells. Furthermore, Con-AS existed in the medium-sized lymphocytes, which were fractionated on the basis of cell size, while SpS in the large-sized lymphocytes. A higher proportion of T-cells, bearing Fc receptors for IgG, was observed in the larger-sized lymphocyte fractions. Cell numbers in the large-sized lymphocyte fraction tended to increase with the advances of tumors. From these results, it is suggested that higher presence of suppressor precursors and the increase of SpS activities may occur in cancer patients, depending on the tumor advancing.

  9. Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

    Directory of Open Access Journals (Sweden)

    Hua-Sheng Chiu

    2018-04-01

    Full Text Available Summary: Long noncoding RNAs (lncRNAs are commonly dysregulated in tumors, but only a handful are known to play pathophysiological roles in cancer. We inferred lncRNAs that dysregulate cancer pathways, oncogenes, and tumor suppressors (cancer genes by modeling their effects on the activity of transcription factors, RNA-binding proteins, and microRNAs in 5,185 TCGA tumors and 1,019 ENCODE assays. Our predictions included hundreds of candidate onco- and tumor-suppressor lncRNAs (cancer lncRNAs whose somatic alterations account for the dysregulation of dozens of cancer genes and pathways in each of 14 tumor contexts. To demonstrate proof of concept, we showed that perturbations targeting OIP5-AS1 (an inferred tumor suppressor and TUG1 and WT1-AS (inferred onco-lncRNAs dysregulated cancer genes and altered proliferation of breast and gynecologic cancer cells. Our analysis indicates that, although most lncRNAs are dysregulated in a tumor-specific manner, some, including OIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergistically dysregulate cancer pathways in multiple tumor contexts. : Chiu et al. present a pan-cancer analysis of lncRNA regulatory interactions. They suggest that the dysregulation of hundreds of lncRNAs target and alter the expression of cancer genes and pathways in each tumor context. This implies that hundreds of lncRNAs can alter tumor phenotypes in each tumor context. Keywords: lncRNA, regulation, modulation, cancer gene, pan-cancer, noncoding RNA, microRNA, RNA-binding proteins, interactome

  10. Characteristics of DTH suppressor cells in mice infected with Candida albicans.

    Science.gov (United States)

    Valdez, J C; Mesón, O E; Sirena, A; de Alderete, N G

    1987-05-01

    Inoculation of 10(8) C. albicans intraperitoneally into Balb/c mice at given dosage was reported to induce suppression of antigen-specific delayed-type hypersensitivity. Adoptive transfer of spleen cells into normal syngeneic mice pre-treated with Cyclophosphamide confirmed the existence of suppressor cells in mice. Such cells were sensitive to treatment with anti-theta serum and complement, non-adherent to Sephadex G-10. A pretreatment of the mice with Cyclophosphamide eliminated DTH suppression. Treatment with antimacrophage agents via intraperitoneal abrogated suppression only if being effected before inoculation of alive 10(8) Candida albicans. It is concluded that the spleen suppressor cell is a T-lymphocyte whose precursor is Cyclophosphamide-sensitive, requiring the macrophage to be induced.

  11. ZNF649, a novel Kruppel type zinc-finger protein, functions as a transcriptional suppressor

    International Nuclear Information System (INIS)

    Yang Hong; Yuan Wuzhou; Wang Ying; Zhu Chuanbing; Liu Bisheng; Wang Yuequn; Yang, Dan; Li Yongqing; Wang Canding; Wu Xiushan; Liu Mingyao

    2005-01-01

    Cardiac differentiation involves a cascade of coordinated gene expression that regulates cell proliferation and matrix protein formation in a defined temporo-spatial manner. Many of the KRAB-ZFPs are involved in cardiac development or cardiovascular diseases. Here we report the identification and characterization of a novel human zinc-finger gene named ZNF649. The cDNA of ZNF649 is 3176 bp, encoding a protein of 505 amino acids in the nuclei. Northern blot analysis indicates that ZNF649 is expressed in most of the examined human adult and embryonic tissues. ZNF649 is a transcription suppressor when fused to GAL-4 DNA-binding domain and cotransfected with VP-16. Overexpression of ZNF649 in COS-7 cells inhibits the transcriptional activities of SRE and AP-1. Deletion analysis with a series of truncated fusion proteins indicates that the KRAB motif is a basal repression domain when the truncated fusion proteins were assayed for the transcriptional activities of SRE and AP-1. These results suggest that ZNF649 protein may act as a transcriptional repressor in mitogen-activated protein kinase signaling pathway to mediate cellular functions

  12. The APC tumor suppressor is required for epithelial cell polarization and three-dimensional morphogenesis

    Science.gov (United States)

    Lesko, Alyssa C.; Goss, Kathleen H.; Yang, Frank F.; Schwertner, Adam; Hulur, Imge; Onel, Kenan; Prosperi, Jenifer R.

    2015-01-01

    The Adenomatous Polyposis Coli (APC) tumor suppressor has been previously implicated in the control of apical-basal polarity; yet, the consequence of APC loss-of-function in epithelial polarization and morphogenesis has not been characterized. To test the hypothesis that APC is required for the establishment of normal epithelial polarity and morphogenesis programs, we generated APC-knockdown epithelial cell lines. APC depletion resulted in loss of polarity and multi-layering on permeable supports, and enlarged, filled spheroids with disrupted polarity in 3D culture. Importantly, these effects of APC knockdown were independent of Wnt/β-catenin signaling, but were rescued with either full-length or a carboxy (c)-terminal segment of APC. Moreover, we identified a gene expression signature associated with APC knockdown that points to several candidates known to regulate cell-cell and cell-matrix communication. Analysis of epithelial tissues from mice and humans carrying heterozygous APC mutations further support the importance of APC as a regulator of epithelial behavior and tissue architecture. These data also suggest that the initiation of epithelial-derived tumors as a result of APC mutation or gene silencing may be driven by loss of polarity and dysmorphogenesis. PMID:25578398

  13. A viral suppressor protein inhibits host RNA silencing by hooking up with Argonautes

    KAUST Repository

    Jin, Hailing; Zhu, Jian-Kang

    2010-01-01

    RNA viruses are particularly vulnerable to RNAi-based defenses in the host, and thus have evolved specific proteins, known as viral suppressors of RNA silencing (VSRs), as a counterdefense. In this issue of Genes & Development, Azevedo and colleagues (pp. 904-915) discovered that P38, the VSR of Turnip crinkle virus, uses its glycine/tryptophane (GW) motifs as an ARGONAUTE (AGO) hook to attract and disarm the host's essential effector of RNA silencing. Several GW motif-containing cellular proteins are known to be important partners of AGOs in RNA silencing effector complexes in yeast, plants, and animals. The GW motif appears to be a versatile and effective tool for regulating the activities of RNA silencing pathways, and the use of GW mimicry to compete for and inhibit host AGOs may be a strategy used by many pathogens to counteract host RNAi-based defenses. © 2010 by Cold Spring Harbor Laboratory Press.

  14. Maternally expressed gene 3, an imprinted noncoding RNA gene, is associated with meningioma pathogenesis and progression.

    Science.gov (United States)

    Zhang, Xun; Gejman, Roger; Mahta, Ali; Zhong, Ying; Rice, Kimberley A; Zhou, Yunli; Cheunsuchon, Pornsuk; Louis, David N; Klibanski, Anne

    2010-03-15

    Meningiomas are common tumors, representing 15% to 25% of all central nervous system tumors. NF2 gene inactivation on chromosome 22 has been shown as an early event in tumorigenesis; however, few factors underlying tumor growth and progression have been identified. The chromosomal abnormalities of 14q32 are often associated with meningioma pathogenesis and progression; therefore, it has been proposed that an as yet unidentified tumor suppressor is present at this locus. Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 which encodes a noncoding RNA with an antiproliferative function. We found that MEG3 mRNA is highly expressed in normal arachnoidal cells. However, MEG3 is not expressed in the majority of human meningiomas or the human meningioma cell lines IOMM-Lee and CH157-MN. There is a strong association between loss of MEG3 expression and tumor grade. Allelic loss at the MEG3 locus is also observed in meningiomas, with increasing prevalence in higher grade tumors. In addition, there is an increase in CpG methylation within the promoter and the imprinting control region of MEG3 gene in meningiomas. Functionally, MEG3 suppresses DNA synthesis in both IOMM-Lee and CH157-MN cells by approximately 60% in bromodeoxyuridine incorporation assays. Colony-forming efficiency assays show that MEG3 inhibits colony formation in CH157-MN cells by approximately 80%. Furthermore, MEG3 stimulates p53-mediated transactivation in these cell lines. Therefore, these data are consistent with the hypothesis that MEG3, which encodes a noncoding RNA, may be a tumor suppressor gene at chromosome 14q32 involved in meningioma progression via a novel mechanism.

  15. PTPN13, a Fas-associated protein tyrosine phosphatase, is located on the long arm of chromosome 4 at band q21.3

    Energy Technology Data Exchange (ETDEWEB)

    Inazawa, Johji; Ariyama, Takeshi; Abe, Tatsuo [Kyoto Prefectural Univ. of Medicine (Japan)] [and others

    1996-01-15

    PTPN13 is a protein tyrosine phosphatase that associates with the C-terminal negative regulatory domain in the Fas (APO-1/CD95) receptor. The PTPN13 protein contains six GLGF repeats that have been found in the rat postsynaptic density protein (PSD-95) and the Drosophila tumor suppressor protein, lethal-(1)-disclarge-1 (dlg-1). The localization of the PTPN13 gene to human chromosome 4q21.3 was determined by both FISH and PCR analysis of somatic cell hybrids. This 4q21.3 chromosomal region contains a gene for autosomal dominant polycystic kidney disease as well as the region frequently deleted in liver and ovarian cancers, suggesting that PTPN13 is a candidate for one of the putative tumor suppressor genes on the long arm of chromosome 4. 21 refs., 1 fig.

  16. Repression of estrogen receptor β function by putative tumor suppressor DBC1

    International Nuclear Information System (INIS)

    Koyama, Satoshi; Wada-Hiraike, Osamu; Nakagawa, Shunsuke; Tanikawa, Michihiro; Hiraike, Haruko; Miyamoto, Yuichiro; Sone, Kenbun; Oda, Katsutoshi; Fukuhara, Hiroshi; Nakagawa, Keiichi; Kato, Shigeaki; Yano, Tetsu; Taketani, Yuji

    2010-01-01

    It has been well established that estrogen is involved in the pathophysiology of breast cancer. Estrogen receptor (ER) α appears to promote the proliferation of cancer tissues, while ERβ can protect against the mitogenic effect of estrogen in breast tissue. The expression status of ERα and ERβ may greatly influence on the development, treatment, and prognosis of breast cancer. Previous studies have indicated that the deleted in breast cancer 1 (DBC1/KIAA1967) gene product has roles in regulating functions of nuclear receptors. The gene encoding DBC1 is a candidate for tumor suppressor identified by genetic search for breast cancer. Caspase-dependent processing of DBC1 promotes apoptosis, and depletion of the endogenous DBC1 negatively regulates p53-dependent apoptosis through its specific inhibition of SIRT1. In addition, DBC1 modulates ERα expression and promotes breast cancer cell survival by binding to ERα. Here we report an ERβ-specific repressive function of DBC1. Immunoprecipitation and immunofluorescence studies show that ERβ and DBC1 interact in a ligand-independent manner similar to ERα. In vitro pull-down assays revealed a direct interaction between DBC1 amino-terminus and activation function-1/2 domain of ERβ. Although DBC1 shows no influence on the ligand-dependent transcriptional activation function of ERα, the expression of DBC1 negatively regulates the ligand-dependent transcriptional activation function of ERβin vivo, and RNA interference-mediated depletion of DBC1 stimulates the transactivation function of ERβ. These results implicate the principal role of DBC1 in regulating ERβ-dependent gene expressions.

  17. Codon 201Gly Polymorphic Type of the DCC Gene is Related to Disseminated Neuroblastoma

    Directory of Open Access Journals (Sweden)

    Xiao-Tang Kong

    2001-01-01

    Full Text Available The deleted in colorectal carcinoma (DCC gene is a potential tumor- suppressor gene on chromosome 18821.3. The relatively high frequency of loss of heterozygosity (LOH and loss of expression of this gene in neuroblastoma, especially in the advanced stages, imply the possibility of involvement of the DCC gene in progression of neuroblastoma. However, only few typical mutations have been identified in this gene, indicating that other possible mechanisms for the inactivation of this gene may exist. A polymorphic change (Arg to Gly at DCC codon 201 is related to advanced colorectal carcinoma and increases in the tumors with absent DCC protein expression. In order to understand whether this change is associated with the development or progression of neuroblastoma, we investigated codon 201 polymorphism of the DCC gene in 102 primary neuroblastomas by polymerase chain reaction single-strand conformation polymorphism. We found no missense or nonsense mutations, but a polymorphic change from CGA (Arg to GGA (Gly at codon 201 resulting in three types of polymorphism: codon 201Gly type, codon 201Arg/Gly type, and codon 201Arg type. The codon 201Gly type occurred more frequently in disseminated (stages IV and IVs neuroblastomas (72% than in localized (stages I, II, and III tumors (48% (P=.035, and normal controls (38% (P=.024. In addition, the codon 201Gly type was significantly more common in tumors found clinically (65% than in those found by mass screening (35% (P=.002. The results suggested that the codon 201Gly type of the DCC gene might be associated with a higher risk of disseminating neuroblastoma.

  18. Effect of duct shape, Mach number, and lining construction on measured suppressor attenuation and comparison with theory

    Science.gov (United States)

    Olsen, W. A.; Krejsa, E. A.; Coats, J. W.

    1972-01-01

    Noise attenuation was measured for several types of cylindrical suppressors that use a duct lining composed of honeycomb cells covered with a perforated plate. The experimental technique used gave attenuation data that were repeatable and free of noise floors and other sources of error. The suppressor length, the effective acoustic diameter, suppressor shape and flow velocity were varied. The agreement among the attenuation data and two widely used analytical models was generally satisfactory. Changes were also made in the construction of the acoustic lining to measure their effect on attenuation. One of these produced a very broadband muffler.

  19. The tumor suppressor role of miR-124 in osteosarcoma.

    Directory of Open Access Journals (Sweden)

    Shuo Geng

    Full Text Available MicroRNAs have crucial roles in development and progression of human cancers, including osteosarcoma. Recent studies have shown that miR-124 was down-regulated in many cancers; however, the role of miR-124 in osteosarcoma development is unknown. In this study, we demonstrate that expression of miR-124 is significantly downregulated in osteosarcoma tissues and cell lines, compared to the adjacent tissues. The expression of miR-124 in the metastases osteosarcoma tissues was lower than that in non- metastases tissues. We identified and confirmed Rac1 as a novel, direct target of miR-124 using prediction algorithms and luciferase reporter gene assays. Overexpression of miR-124 suppressed Rac1 protein expression and attenuated cell proliferation, migration, and invasion and induced apoptosis in MG-63 and U2OS in vitro. Moreover, overexpression of Rac1 in miR-124-transfected osteosarcoma cells effectively rescued the inhibition of cell invasion caused by miR-124. Therefore, our results demonstrate that miR-124 is a tumor suppressor miRNA and suggest that this miRNA could be a potential target for the treatment of osteosarcoma in future.

  20. Elicitation of hypersensitive responses in Nicotiana glutinosa by the suppressor of RNA silencing protein P0 from poleroviruses.

    Science.gov (United States)

    Wang, Ken-Der; Empleo, Roman; Nguyen, Tan Tri V; Moffett, Peter; Sacco, Melanie Ann

    2015-06-01

    Plant disease resistance (R) proteins that confer resistance to viruses recognize viral gene products with diverse functions, including viral suppressors of RNA silencing (VSRs). The P0 protein from poleroviruses is a VSR that targets the ARGONAUTE1 (AGO1) protein for degradation, thereby disrupting RNA silencing and antiviral defences. Here, we report resistance against poleroviruses in Nicotiana glutinosa directed against Turnip yellows virus (TuYV) and Potato leafroll virus (PLRV). The P0 proteins from TuYV (P0(T) (u) ), PLRV (P0(PL) ) and Cucurbit aphid-borne yellows virus (P0(CA) ) were found to elicit a hypersensitive response (HR) in N. glutinosa accession TW59, whereas other accessions recognized P0(PL) only. Genetic analysis showed that recognition of P0(T) (u) by a resistance gene designated RPO1 (Resistance to POleroviruses 1) is inherited as a dominant allele. Expression of P0 from a Potato virus X (PVX) expression vector transferred recognition to the recombinant virus on plants expressing RPO1, supporting P0 as the unique Polerovirus factor eliciting resistance. The induction of HR required a functional P0 protein, as P0(T) (u) mutants with substitutions in the F-box motif that abolished VSR activity were unable to elicit HR. We surmised that the broad P0 recognition seen in TW59 and the requirement for the F-box protein motif could indicate detection of P0-induced AGO1 degradation and disruption of RNA silencing; however, other viral silencing suppressors, including the PVX P25 that also causes AGO1 degradation, failed to elicit HR in N. glutinosa. Investigation of P0 elicitation of RPO1 could provide insight into P0 activities within the cell that trigger resistance. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  1. Alloantigen-specific suppressor T cells are not inhibited by cyclosporin A, but do require IL 2 for activation

    International Nuclear Information System (INIS)

    Bucy, R.P.

    1986-01-01

    Alloantigen-specific suppressor T cells are activated from normal murine spleen cells in mixed lymphocyte reactions (MLR). These T cells are radioresistant and suppress the activation of cytotoxic T lymphocytes (CTL) in second primary MLR cultures. This report demonstrates that cyclosporin A (CsA) blocks the activation of these suppressor cells at a dose of 1 microgram/ml. However, reconstitution of CsA blocked cultures with IL 2 restores the activation of the suppressor T cells, but fails to significantly restore the activation of CTL in these same cultures. This differential activation requirement was used to establish T cell lines that demonstrate enriched suppressor cell activity but depletion of CTL activity. These findings are discussed in terms of the mechanism of action of CsA in these distinct T cell subsets and the relevance to models of allograft unresponsiveness

  2. Requirement of the ATM/p53 tumor suppressor pathway for glucose homeostasis.

    Science.gov (United States)

    Armata, Heather L; Golebiowski, Diane; Jung, Dae Young; Ko, Hwi Jin; Kim, Jason K; Sluss, Hayla K

    2010-12-01

    Ataxia telangiectasia (A-T) patients can develop multiple clinical pathologies, including neuronal degeneration, an elevated risk of cancer, telangiectasias, and growth retardation. Patients with A-T can also exhibit an increased risk of insulin resistance and type 2 diabetes. The ATM protein kinase, the product of the gene mutated in A-T patients (Atm), has been implicated in metabolic disease, which is characterized by insulin resistance and increased cholesterol and lipid levels, blood pressure, and atherosclerosis. ATM phosphorylates the p53 tumor suppressor on a site (Ser15) that regulates transcription activity. To test whether the ATM pathway that regulates insulin resistance is mediated by p53 phosphorylation, we examined insulin sensitivity in mice with a germ line mutation that replaces the p53 phosphorylation site with alanine. The loss of p53 Ser18 (murine Ser15) led to increased metabolic stress, including severe defects in glucose homeostasis. The mice developed glucose intolerance and insulin resistance. The insulin resistance correlated with the loss of antioxidant gene expression and decreased insulin signaling. N-Acetyl cysteine (NAC) treatment restored insulin signaling in late-passage primary fibroblasts. The addition of an antioxidant in the diet rendered the p53 Ser18-deficient mice glucose tolerant. This analysis demonstrates that p53 phosphorylation on an ATM site is an important mechanism in the physiological regulation of glucose homeostasis.

  3. DNA methylation of PTEN gene promoter region is not correlated ...

    African Journals Online (AJOL)

    Tumor suppressor gene PTEN plays an important role in cell cycle. Disorder of PTEN protein can cause cell growth and division in an uncontrolled way, which can lead to the formation of tumors. It has been proven that epigenetic mechanisms, such as promoter hypermethylation, may account for inactivation of PTEN in a ...

  4. Tumor suppressor genes that escape from X-inactivation contribute to cancer sex bias

    OpenAIRE

    Dunford, Andrew; Weinstock, David M.; Savova, Virginia; Schumacher, Steven E.; Cleary, John P.; Yoda, Akinori; Sullivan, Timothy J.; Hess, Julian M.; Gimelbrant, Alexander A.; Beroukhim, Rameen; Lawrence, Michael S.; Getz, Gad; Lane, Andrew A.

    2016-01-01

    There is a striking and unexplained male predominance across many cancer types. A subset of X chromosome (chrX) genes can escape X-inactivation, which would protect females from complete functional loss by a single mutation. To identify putative “Escape from X-Inactivation Tumor Suppressor” (EXITS) genes, we compared somatic alterations from >4100 cancers across 21 tumor types for sex bias. Six of 783 non-pseudoautosomal region (PAR) chrX genes (ATRX, CNKSR2, DDX3X, KDM5C, KDM6A, and MAGEC3) ...

  5. Dietary fat and risk of colon and rectal cancer with aberrant MLH1 expression, APC or KRAS genes.

    NARCIS (Netherlands)

    Weijenberg, M.P.; Luchtenborg, M.; Goeij, A.F. de; Brink, M.; Muijen, G.N.P. van; Bruine, A.P. de; Goldbohm, R.A.; Brandt, P.A. van den

    2007-01-01

    OBJECTIVE: To investigate baseline fat intake and the risk of colon and rectal tumors lacking MLH1 (mutL homolog 1, colon cancer, nonpolyposis type 2) repair gene expression and harboring mutations in the APC (adenomatous polyposis coli) tumor suppressor gene and in the KRAS (v-Ki-ras2 Kirsten rat

  6. Mutation and Methylation Analysis of the Chromodomain-Helicase-DNA Binding 5 Gene in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Kylie L. Gorringe

    2008-11-01

    Full Text Available Chromodomain, helicase, DNA binding 5 (CHD5 is a member of a subclass of the chromatin remodeling Swi/Snf proteins and has recently been proposed as a tumor suppressor in a diverse range of human cancers. We analyzed all 41 coding exons of CHD5 for somatic mutations in 123 primary ovarian cancers as well as 60 primary breast cancers using high-resolution melt analysis. We also examined methylation of the CHD5 promoter in 48 ovarian cancer samples by methylation-specific single-stranded conformation polymorphism and bisulfite sequencing. In contrast to previous studies, no mutations were identified in the breast cancers, but somatic heterozygous missense mutations were identified in 3 of 123 ovarian cancers. We identified promoter methylation in 3 of 45 samples with normal CHD5 and in 2 of 3 samples with CHD5 mutation, suggesting these tumors may have biallelic inactivation of CHD5. Hemizygous copy number loss at CHD5 occurred in 6 of 85 samples as assessed by single nucleotide polymorphism array. Tumors with CHD5 mutation or methylation were more likely to have mutation of KRAS or BRAF (P = .04. The aggregate frequency of CHD5 haploinsufficiency or inactivation is 16.2% in ovarian cancer. Thus, CHD5 may play a role as a tumor suppressor gene in ovarian cancer; however, it is likely that there is another target of the frequent copy number neutral loss of heterozygosity observed at 1p36.

  7. Loss of heterozygosity of chromosome 15 in human lung carcinomas

    International Nuclear Information System (INIS)

    Mitchell, C.E.; Palmisano, W.A.; Lechner, J.F.

    1994-01-01

    Loss of heterozygosity (LOH) in tumors may be associated with the inactivation of tumor suppressor genes. A tumor suppressor gene for lung cancer may reside on chromosome 15, because deletions in this chromosome are frequently observed. Recently, it was reported that a newly discovered gene, GTPase-activating protein-3 (GAP3) maps to chromosome 15. GAP3 is a member of a family of GAP-related genes. Although the precise function of GAP3 is not known, it is thought that GAP3 is involved in the regulation of ras-like GTPase activities. Ras proteins have a low intrinsic activity, and their inactivation is dependent on GAPS in vivo. Oncogenic mutants of ras proteins, for example, at codons 12, 13, or 61, are resistant to GAP-mediated GTPase stimulation and are constituitively locked in their active, GTP-bound states. The purpose of this investigation was to determine the frequency and extent of LOH of GAP3 in a group of patients with lung cancer

  8. CADM1 is a strong neuroblastoma candidate gene that maps within a 3.72 Mb critical region of loss on 11q23

    International Nuclear Information System (INIS)

    Michels, Evi; Speleman, Frank; Hoebeeck, Jasmien; De Preter, Katleen; Schramm, Alexander; Brichard, Bénédicte; De Paepe, Anne; Eggert, Angelika; Laureys, Geneviève; Vandesompele, Jo

    2008-01-01

    Recurrent loss of part of the long arm of chromosome 11 is a well established hallmark of a subtype of aggressive neuroblastomas. Despite intensive mapping efforts to localize the culprit 11q tumour suppressor gene, this search has been unsuccessful thus far as no sufficiently small critical region could be delineated for selection of candidate genes. To refine the critical region of 11q loss, the chromosome 11 status of 100 primary neuroblastoma tumours and 29 cell lines was analyzed using a BAC array containing a chromosome 11 tiling path. For the genes mapping within our refined region of loss, meta-analysis on published neuroblastoma mRNA gene expression datasets was performed for candidate gene selection. The DNA methylation status of the resulting candidate gene was determined using re-expression experiments by treatment of neuroblastoma cells with the demethylating agent 5-aza-2'-deoxycytidine and bisulphite sequencing. Two small critical regions of loss within 11q23 at chromosomal band 11q23.1-q23.2 (1.79 Mb) and 11q23.2-q23.3 (3.72 Mb) were identified. In a first step towards further selection of candidate neuroblastoma tumour suppressor genes, we performed a meta-analysis on published expression profiles of 692 neuroblastoma tumours. Integration of the resulting candidate gene list with expression data of neuroblastoma progenitor cells pinpointed CADM1 as a compelling candidate gene. Meta-analysis indicated that CADM1 expression has prognostic significance and differential expression for the gene was noted in unfavourable neuroblastoma versus normal neuroblasts. Methylation analysis provided no evidence for a two-hit mechanism in 11q deleted cell lines. Our study puts CADM1 forward as a strong candidate neuroblastoma suppressor gene. Further functional studies are warranted to elucidate the role of CADM1 in neuroblastoma development and to investigate the possibility of CADM1 haploinsufficiency in neuroblastoma

  9. Myeloid-derived suppressor activity is mediated by monocytic lineages maintained by continuous inhibition of extrinsic and intrinsic death pathways.

    Science.gov (United States)

    Haverkamp, Jessica M; Smith, Amber M; Weinlich, Ricardo; Dillon, Christopher P; Qualls, Joseph E; Neale, Geoffrey; Koss, Brian; Kim, Young; Bronte, Vincenzo; Herold, Marco J; Green, Douglas R; Opferman, Joseph T; Murray, Peter J

    2014-12-18

    Nonresolving inflammation expands a heterogeneous population of myeloid suppressor cells capable of inhibiting T cell function. This heterogeneity has confounded the functional dissection of individual myeloid subpopulations and presents an obstacle for antitumor immunity and immunotherapy. Using genetic manipulation of cell death pathways, we found the monocytic suppressor-cell subset, but not the granulocytic subset, requires continuous c-FLIP expression to prevent caspase-8-dependent, RIPK3-independent cell death. Development of the granulocyte subset requires MCL-1-mediated control of the intrinsic mitochondrial death pathway. Monocytic suppressors tolerate the absence of MCL-1 provided cytokines increase expression of the MCL-1-related protein A1. Monocytic suppressors mediate T cell suppression, whereas their granulocytic counterparts lack suppressive function. The loss of the granulocytic subset via conditional MCL-1 deletion did not alter tumor incidence implicating the monocytic compartment as the functionally immunosuppressive subset in vivo. Thus, death pathway modulation defines the development, survival, and function of myeloid suppressor cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Molecular cloning, phylogenetic analysis, and expression patterns of LATERAL SUPPRESSOR-LIKE and REGULATOR OF AXILLARY MERISTEM FORMATION-LIKE genes in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Fambrini, Marco; Salvini, Mariangela; Pugliesi, Claudio

    2017-03-01

    The wild sunflower (Helianthus annuus) plants develop a highly branched form with numerous small flowering heads. The origin of a no branched sunflower, producing a single large head, has been a key event in the domestication process of this species. The interaction between hormonal factors and several genes organizes the initiation and outgrowth of axillary meristems (AMs). From sunflower, we have isolated two genes putatively involved in this process, LATERAL SUPPRESSOR (LS)-LIKE (Ha-LSL) and REGULATOR OF AXILLARY MERISTEM FORMATION (ROX)-LIKE (Ha-ROXL), encoding for a GRAS and a bHLH transcription factor (TF), respectively. Typical amino acid residues and phylogenetic analyses suggest that Ha-LSL and Ha-ROXL are the orthologs of the branching regulator LS and ROX/LAX1, involved in the growth habit of both dicot and monocot species. qRT-PCR analyses revealed a high accumulation of Ha-LSL transcripts in roots, vegetative shoots, and inflorescence shoots. By contrast, in internodal stems and young leaves, a lower amount of Ha-LSL transcripts was observed. A comparison of transcription patterns between Ha-LSL and Ha-ROXL revealed some analogies but also remarkable differences; in fact, the gene Ha-ROXL displayed a low expression level in all organs analyzed. In situ hybridization (ISH) analysis showed that Ha-ROXL transcription was strongly restricted to a small domain within the boundary zone separating the shoot apical meristem (SAM) and the leaf primordia and in restricted regions of the inflorescence meristem, beforehand the separation of floral bracts from disc flower primordia. These results suggested that Ha-ROXL may be involved to establish a cell niche for the initiation of AMs as well as flower primordia. The accumulation of Ha-LSL transcripts was not restricted to the boundary zones in vegetative and inflorescence shoots, but the mRNA activity was expanded in other cellular domains of primary shoot apical meristem as well as AMs. In addition, Ha

  11. Mutation and Expression of the DCC Gene in Human Lung Cancer

    Directory of Open Access Journals (Sweden)

    Takashi Kohno

    2000-07-01

    Full Text Available Chromosome 18q is frequently deleted in lung cancers, a common region of 18q deletions was mapped to chromosome 18g21. Since the DCC candidate tumor suppressor gene has been mapped in this region, mutation and expression of the DCC gene were examined in 46 lung cancer cell lines, consisting of 14 small cell lung carcinomas (SCLCs and 32 non-small cell lung carcinomas (NSCLCs, to elucidate the pathogenetic significance of DCC alterations in human lung carcinogenesis. A heterozygous missense mutation was detected in a NSCLC cell line, Ma26, while homozygous deletion was not detected in any of the cell lines. The DCC gene was expressed in 11 (24% of the 46 cell lines, the incidence of DCC expression was significantly higher in SCLCs (7/14, 50% than in NSCLCs (4/32, 13% (P = .01, Fisher's exact test. Therefore, genetic alterations of DCC are infrequent; however, the levels of DCC expression vary among lung cancer cells, in particular, between SCLCs and NSCLCs. The present result does not implicate DCC as a specific mutational target of 18q deletions in human lung cancer; however, it suggests that DCC is a potential target of inactivation by genetic defects including intron or promoter mutations and/or epigenetic alterations. The present result also suggests that DCC expression is associated with some properties of SCLCs, such as a neuroendocrine (NE feature.

  12. The Ras suppressor-1 (RSU-1 in cancer

    Directory of Open Access Journals (Sweden)

    Lefteris C Zacharia

    2017-04-01

    Full Text Available Primary tumors are seldom the cause of death for cancer patients as most patients die from metastatic disease. Thus, deciphering metastatic mechanisms and key molecules involved is of utmost importance for the improved survival of cancer patients. Metastasis is a complex process in which cancer cells dissociate from the original tumor and spread to distant sites of the body. During the metastatic process, cancer cells lose contact both with the extracellular matrix (ECM and the neighboring cells within the primary tumor, thus invading though surrounding tissues. Therefore, ECM, and ECM-related adhesion proteins play a critical role in the metastatic process. Ras suppressor-1 (RSU-1 was first identified as a suppressor of Ras-dependent oncogenic transformation and is localized to cell-ECM adhesions where it is known to interact with the pro-survival adhesion protein PINCH-1. Although the connection to cancer is obvious, little is known regarding its expression in various cancer types. This opinion piece is focusing on recent literature regarding the expression of RSU-1 in various cancer types and the possible molecular mechanism of its action, pointing towards questions that need still to be addressed in this research field.

  13. Genetic variability and evolutionary implications of RNA silencing suppressor genes in RNA1 of sweet potato chlorotic stunt virus isolates infecting sweetpotato and related wild species.

    Directory of Open Access Journals (Sweden)

    Arthur K Tugume

    Full Text Available BACKGROUND: The bipartite single-stranded RNA genome of Sweet potato chlorotic stunt virus (SPCSV, genus Crinivirus; Closteroviridae encodes a Class 1 RNase III (RNase3, a putative hydrophobic protein (p7 and a 22-kDa protein (p22 from genes located in RNA1. RNase3 and p22 suppress RNA silencing, the basal antiviral defence mechanism in plants. RNase3 is sufficient to render sweetpotato (Ipomoea batatas virus-susceptible and predisposes it to development of severe diseases following infection with unrelated virus. The incidence, strains and gene content of SPCSV infecting wild plant species have not been studied. METHODOLOGY/PRINCIPAL FINDINGS: Thirty SPCSV isolates were characterized from 10 wild Ipomoea species, Hewittia sublobata or Lepistemon owariensis (family Convolvulaceae in Uganda and compared with 34 local SPCSV isolates infecting sweetpotatoes. All isolates belonged to the East African (EA strain of SPCSV and contained RNase3 and p7, but p22 was not detected in six isolates. The three genes showed only limited genetic variability and the proteins were under purifying selection. SPCSV isolates lacking p22 synergized with Sweet potato feathery mottle virus (SPFMV, genus potyvirus; Potyviridae and caused severe symptoms in co-infected sweetpotato plants. One SPCSV isolate enhanced accumulation of SPFMV, but no severe symptoms developed. A new whitefly-transmitted virus (KML33b encoding an RNase3 homolog (<56% identity to SPCSV RNase3 able to suppresses sense-mediated RNA silencing was detected in I. sinensis. CONCLUSIONS/SIGNIFICANCE: SPCSV isolates infecting wild species and sweetpotato in Uganda were genetically undifferentiated, suggesting inter-species transmission of SPCSV. Most isolates in Uganda contained p22, unlike SPCSV isolates characterized from other countries and continents. Enhanced accumulation of SPFMV and increased disease severity were found to be uncoupled phenotypic outcomes of RNase3-mediated viral synergism in

  14. CDKN1C/p57kip2 is a candidate tumor suppressor gene in human breast cancer

    International Nuclear Information System (INIS)

    Larson, Pamela S; Schlechter, Benjamin L; King, Chia-Lin; Yang, Qiong; Glass, Chelsea N; Mack, Charline; Pistey, Robert; Morenas, Antonio de las; Rosenberg, Carol L

    2008-01-01

    CDKN1C (also known as p57 KIP2 ) is a cyclin-dependent kinase inhibitor previously implicated in several types of human cancer. Its family members (CDKN1A/p21 CIP1 and B/p27 KIP1 ) have been implicated in breast cancer, but information about CDKN1C's role is limited. We hypothesized that decreased CDKN1C may be involved in human breast carcinogenesis in vivo. We determined rates of allele imbalance or loss of heterozygosity (AI/LOH) in CDKN1C, using an intronic polymorphism, and in the surrounding 11p15.5 region in 82 breast cancers. We examined the CDKN1C mRNA level in 10 cancers using quantitative real-time PCR (qPCR), and the CDKN1C protein level in 20 cancers using immunohistochemistry (IHC). All samples were obtained using laser microdissection. Data were analyzed using standard statistical tests. AI/LOH at 11p15.5 occurred in 28/73 (38%) informative cancers, but CDKN1C itself underwent AI/LOH in only 3/16 (19%) cancers (p = ns). In contrast, CDKN1C mRNA levels were reduced in 9/10 (90%) cancers (p < 0.0001), ranging from 2–60% of paired normal epithelium. Similarly, CDKN1C protein staining was seen in 19/20 (95%) cases' normal epithelium but in only 7/14 (50%) cases' CIS (p < 0.004) and 5/18 (28%) cases' IC (p < 0.00003). The reduction appears primarily due to loss of CDKN1C expression from myoepithelial layer cells, which stained intensely in 17/20 (85%) normal lobules, but in 0/14 (0%) CIS (p < 0.00001). In contrast, luminal cells displayed less intense, focal staining fairly consistently across histologies. Decreased CDKN1C was not clearly associated with tumor grade, histology, ER, PR or HER2 status. CDKN1C is expressed in normal epithelium of most breast cancer cases, mainly in the myothepithelial layer. This expression decreases, at both the mRNA and protein level, in the large majority of breast cancers, and does not appear to be mediated by AI/LOH at the gene. Thus, CDKN1C may be a breast cancer tumor suppressor

  15. A viral suppressor protein inhibits host RNA silencing by hooking up with Argonautes

    KAUST Repository

    Jin, Hailing

    2010-05-01

    RNA viruses are particularly vulnerable to RNAi-based defenses in the host, and thus have evolved specific proteins, known as viral suppressors of RNA silencing (VSRs), as a counterdefense. In this issue of Genes & Development, Azevedo and colleagues (pp. 904-915) discovered that P38, the VSR of Turnip crinkle virus, uses its glycine/tryptophane (GW) motifs as an ARGONAUTE (AGO) hook to attract and disarm the host\\'s essential effector of RNA silencing. Several GW motif-containing cellular proteins are known to be important partners of AGOs in RNA silencing effector complexes in yeast, plants, and animals. The GW motif appears to be a versatile and effective tool for regulating the activities of RNA silencing pathways, and the use of GW mimicry to compete for and inhibit host AGOs may be a strategy used by many pathogens to counteract host RNAi-based defenses. © 2010 by Cold Spring Harbor Laboratory Press.

  16. The Value of Suppressor Effects in Explicating the Construct Validity of Symptom Measures

    Science.gov (United States)

    Watson, David; Clark, Lee Anna; Chmielewski, Michael; Kotov, Roman

    2013-01-01

    Suppressor effects are operating when the addition of a predictor increases the predictive power of another variable. We argue that suppressor effects can play a valuable role in explicating the construct validity of symptom measures by bringing into clearer focus opposing elements that are inherent—but largely hidden—in the measure’s overall score. We illustrate this point using theoretically grounded, replicated suppressor effects that have emerged in analyses of the original Inventory of Depression and Anxiety Symptoms (IDAS; Watson et al., 2007) and its expanded second version (IDAS-II; Watson et al., 2012). In Study 1, we demonstrate that the IDAS-II Appetite Gain and Appetite Loss scales contain both (a) a shared distress component that creates a positive correlation between them and (b) a specific symptom component that produces a natural negative association between them (i.e., people who recently have experienced decreased interest in food/loss of appetite are less likely to report a concomitant increase in appetite/weight). In Study 2, we establish that mania scales also contain two distinct elements—namely, high energy/positive emotionality and general distress/dysfunction—that oppose each another in many instances. In both studies, we obtained evidence of suppression effects that were highly robust across different types of respondents (e.g., clinical outpatients, community adults, college students) and using both self-report and interview-based measures. These replicable suppressor effects establish that many homogeneous, unidimensional symptom scales actually contain distinguishable components with distinct—at times, even antagonistic—properties. PMID:23795886

  17. Suppressor of Overexpression of CO 1 Negatively Regulates Dark-Induced Leaf Degreening and Senescence by Directly Repressing Pheophytinase and Other Senescence-Associated Genes in Arabidopsis.

    Science.gov (United States)

    Chen, Junyi; Zhu, Xiaoyu; Ren, Jun; Qiu, Kai; Li, Zhongpeng; Xie, Zuokun; Gao, Jiong; Zhou, Xin; Kuai, Benke

    2017-03-01

    Although the biochemical pathway of chlorophyll (Chl) degradation has been largely elucidated, how Chl is rapidly yet coordinately degraded during leaf senescence remains elusive. Pheophytinase (PPH) is the enzyme for catalyzing the removal of the phytol group from pheophytin a , and PPH expression is significantly induced during leaf senescence. To elucidate the transcriptional regulation of PPH , we used a yeast ( Saccharomyces cerevisiae ) one-hybrid system to screen for its trans-regulators. SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), a key flowering pathway integrator, was initially identified as one of the putative trans-regulators of PPH After dark treatment, leaves of an SOC1 knockdown mutant ( soc1-6 ) showed an accelerated yellowing phenotype, whereas those of SOC1 -overexpressing lines exhibited a partial stay-green phenotype. SOC1 and PPH expression showed a negative correlation during leaf senescence. Substantially, SOC1 protein could bind specifically to the CArG box of the PPH promoter in vitro and in vivo, and overexpression of SOC1 significantly inhibited the transcriptional activity of the PPH promoter in Arabidopsis ( Arabidopsis thaliana ) protoplasts. Importantly, soc1-6 pph-1 (a PPH knockout mutant) double mutant displayed a stay-green phenotype similar to that of pph-1 during dark treatment. These results demonstrated that SOC1 inhibits Chl degradation via negatively regulating PPH expression. In addition, measurement of the Chl content and the maximum photochemical efficiency of photosystem II of soc1-6 and SOC1-OE leaves after dark treatment suggested that SOC1 also negatively regulates the general senescence process. Seven SENESCENCE-ASSOCIATED GENES ( SAGs ) were thereafter identified as its potential target genes, and NONYELLOWING1 and SAG113 were experimentally confirmed. Together, we reveal that SOC1 represses dark-induced leaf Chl degradation and senescence in general in Arabidopsis. © 2017 American Society of Plant Biologists. All

  18. Promoter Methylation of RASSF1A Associates to Adult Secondary Glioblastomas and Pediatric Glioblastomas.

    Science.gov (United States)

    Muñoz, Jorge; Inda, María Del Mar; Lázcoz, Paula; Zazpe, Idoya; Fan, Xing; Alfaro, Jorge; Tuñón, Teresa; Rey, Juan A; Castresana, Javier S

    2012-01-01

    While allelic losses and mutations of tumor suppressor genes implicated in the etiology of astrocytoma have been widely assessed, the role of epigenetics is still a matter of study. We analyzed the frequency of promoter hypermethylation by methylation-specific PCR (MSP) in five tumor suppressor genes (PTEN, MGMT, RASSF1A, p14(ARF), and p16(INK4A)), in astrocytoma samples and cell lines. RASSF1A was the most frequently hypermethylated gene in all grades of astrocytoma samples, in cell lines, and in adult secondary GBM. It was followed by MGMT. PTEN showed a slight methylation signal in only one GBM and one pilocytic astrocytoma, and in two cell lines; while p14(ARF) and p16(INK4A) did not show any evidence of methylation in primary tumors or cell lines. In pediatric GBM, RASSF1A was again the most frequently altered gene, followed by MGMT; PTEN, p14 and p16 showed no alterations. Lack or reduced expression of RASSF1A in cell lines was correlated with the presence of methylation. RASSF1A promoter hypermethylation might be used as a diagnostic marker for secondary GBM and pediatric GBM. Promoter hypermethylation might not be an important inactivation mechanism in other genes like PTEN, p14(ARF) and p16(INK4A), in which other alterations (mutations, homozygous deletions) are prevalent.

  19. DMPD: Suppressor of cytokine signaling (SOCS) 2, a protein with multiple functions. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17070092 Suppressor of cytokine signaling (SOCS) 2, a protein with multiple function...Epub 2006 Oct 27. (.png) (.svg) (.html) (.csml) Show Suppressor of cytokine signaling (SOCS) 2, a protein with multiple function...SOCS) 2, a protein with multiple functions. Authors Rico-Bautista E, Flores-Morales A, Fernandez-Perez L. Pu

  20. Radiation of different human melanoma cell lines increased expression of RHOB. Level of this tumor suppressor gene in different cell lines

    International Nuclear Information System (INIS)

    Notcovich, C.; Molinari, B.; Duran, H.; Delgado González, D.; Sánchez Crespo, R.

    2013-01-01

    Previous results of our group show that a correlation exists between intrinsic radiosensitivity of human melanoma cells and cell death by apoptosis. RhoB is a small GTPase that regulates cytoskeletal organization. Besides, is related to the process of apoptosis in cells exposed to DNA damage as radiation. Also, RhoB levels decrease in a wide variety of tumors with the tumor stage, being considered a tumor suppressor gene due to its antiproliferative and proapoptotic effect. The aim of this study was to analyze the expression of RhoB in different human melanoma cell lines in relation to melanocytes, and evaluate the effect of gamma radiation on the expression of RhoB. We used the A375, SB2 and Meljcell lines, and the derived from melanocytes Pig1. It was found for all three tumor lines RhoB expression levels significantly lower than those of Pig1 (p <0.05), as assessed by semiquantitative RT-PCR . When tumor cells were irradiated to a dose of 2Gyinduction was observed at 3 hours RhoB irradiation. RhoB expression increased in all lines relative to non-irradiated control, showing a greater induction ( p< 0.05) for the more radiosensitive line SB2, consistent with apoptosis in response to radiation. The results allow for the first time in melanoma demonstrate that RhoB, as well as in other tumor types, has a lower expression in tumor cells than their normal counterparts. Moreover, induction in the expression of RhoB in irradiated cells may be associated with the process of radiation-induced apoptosis. The modulation of RhoB could be a new tool to sensitize radioresistant melanoma. (author)

  1. Ionizing radiation induced malignancies in man

    International Nuclear Information System (INIS)

    Dutrillaux, B.

    1997-01-01

    Using data on gene and chromosome alterations in human cancers, it is proposed that most radiation induced cancers are a consequence of recessive mutations of tumor suppressor genes. This explains the long delay between radiation exposure and the cancer onset. As a consequence, radiation induced cancers belong to groups of tumors where no specific translocations (forming or activating oncogenes) but multiple unbalanced chromosome rearrangements (deletions unmasking recessive mutations) exist. This explains why osteosarcomas, malignant fibrous histiocytoma, chondrosarcomas are frequently induced, but not liposarcoma, Ewing sarcomas and rhabdomyosarcomas, among others. A single exception confirms this rule: papillary thyroid cancer, frequently induced in exposed children, in which structural rearrangements frequently form a RET/PTC3 fusion gene. This fusion gene is the results of the inversion of a short segment of chromosome 10, and it is assumed that such rearrangement (small para-centric inversion) can easily occur after exposure to radiations, at contrast with translocations between to genes belonging to different chromosomes. (author)

  2. ABCE1 is a highly conserved RNA silencing suppressor.

    Directory of Open Access Journals (Sweden)

    Kairi Kärblane

    Full Text Available ATP-binding cassette sub-family E member 1 (ABCE1 is a highly conserved protein among eukaryotes and archaea. Recent studies have identified ABCE1 as a ribosome-recycling factor important for translation termination in mammalian cells, yeast and also archaea. Here we report another conserved function of ABCE1. We have previously described AtRLI2, the homolog of ABCE1 in the plant Arabidopsis thaliana, as an endogenous suppressor of RNA silencing. In this study we show that this function is conserved: human ABCE1 is able to suppress RNA silencing in Nicotiana benthamiana plants, in mammalian HEK293 cells and in the worm Caenorhabditis elegans. Using co-immunoprecipitation and mass spectrometry, we found a number of potential ABCE1-interacting proteins that might support its function as an endogenous suppressor of RNA interference. The interactor candidates are associated with epigenetic regulation, transcription, RNA processing and mRNA surveillance. In addition, one of the identified proteins is translin, which together with its binding partner TRAX supports RNA interference.

  3. Tumor suppressor roles of CENP-E and Nsl1 in Drosophila epithelial tissues.

    Science.gov (United States)

    Clemente-Ruiz, Marta; Muzzopappa, Mariana; Milán, Marco

    2014-01-01

    Depletion of spindle assembly checkpoint (SAC) genes in Drosophila epithelial tissues leads to JNK-dependent programmed cell death and additional blockade of the apoptotic program drives tumorigenesis. A recent report proposes that chromosomal instability (CIN) is not the driving force in the tumorigenic response of the SAC-deficient tissue, and that checkpoint proteins exert a SAC-independent tumor suppressor role. This notion is based on observations that the depletion of CENP-E levels or prevention of Bub3 from binding to the kinetochore in Drosophila tissues unable to activate the apoptotic program induces CIN but does not cause hyperproliferation. Here we re-examined this proposal. In contrast to the previous report, we observed that depletion of CENP-E or Nsl1-the latter mediating kinetochore targeting of Bub3-in epithelial tissues unable to activate the apoptotic program induces significant levels of aneuploidy and drives tumor-like growth. The induction of the JNK transcriptional targets Wingless, a mitogenic molecule, and MMP1, a matrix metaloproteinase 1 involved in basement membrane degradation was also observed in these tumors. An identical response of the tissue was previously detected upon depletion of several SAC genes or genes involved in spindle assembly, chromatin condensation, and cytokinesis, all of which have been described to cause CIN. All together, these results reinforce the role of CIN in driving tumorigenesis in Drosophila epithelial tissues and question the proposed SAC-independent roles of checkpoint proteins in suppressing tumorigenesis. Differences in aneuploidy rates might explain the discrepancy between the previous report and our results.

  4. Molecular analysis of the eighteen most frequent mutations in the BRCA1 gene in 63 Chilean breast cancer families

    Directory of Open Access Journals (Sweden)

    LILIAN JARA

    2004-01-01

    Full Text Available BRCA1 gene mutations account for nearly all families with multiple cases of both early onset breast and/or ovarian cancer and about 30% of hereditary breast cancer. Although to date more than 1,237 distinct mutations, polymorphisms, and variants have been described, several mutations have been found to be recurrent in this gene. We have analyzed 63 Chilean breast/ovarian cancer families for eighteen frequent BRCA1 mutations. The analysis of the five exons and two introns in which these mutations are located was made using mismatch PCR assay, ASO hybridization assay, restriction fragment analysis, allele specific PCR assay and direct sequentiation techniques. Two BRCA1 mutations (185delAG and C61G and one variant of unknown significance (E1250K were found in four of these families. Also, a new mutation (4185delCAAG and one previously described polymorphism (E1038G were found in two other families. The 185delAG was found in a 3.17 % of the families and the others were present only in one of the families of this cohort. Therefore these mutations are not prominent in the Chilean population. The variant of unknown significance and the polymorphism detected could represent a founder effect of Spanish origin

  5. Epigenetic upregulation of lncRNAs at 13q14.3 in leukemia is linked to the In Cis downregulation of a gene cluster that targets NF-kB.

    Directory of Open Access Journals (Sweden)

    Angela Garding

    2013-04-01

    Full Text Available Non-coding RNAs are much more common than previously thought. However, for the vast majority of non-coding RNAs, the cellular function remains enigmatic. The two long non-coding RNA (lncRNA genes DLEU1 and DLEU2 map to a critical region at chromosomal band 13q14.3 that is recurrently deleted in solid tumors and hematopoietic malignancies like chronic lymphocytic leukemia (CLL. While no point mutations have been found in the protein coding candidate genes at 13q14.3, they are deregulated in malignant cells, suggesting an epigenetic tumor suppressor mechanism. We therefore characterized the epigenetic makeup of 13q14.3 in CLL cells and found histone modifications by chromatin-immunoprecipitation (ChIP that are associated with activated transcription and significant DNA-demethylation at the transcriptional start sites of DLEU1 and DLEU2 using 5 different semi-quantitative and quantitative methods (aPRIMES, BioCOBRA, MCIp, MassARRAY, and bisulfite sequencing. These epigenetic aberrations were correlated with transcriptional deregulation of the neighboring candidate tumor suppressor genes, suggesting a coregulation in cis of this gene cluster. We found that the 13q14.3 genes in addition to their previously known functions regulate NF-kB activity, which we could show after overexpression, siRNA-mediated knockdown, and dominant-negative mutant genes by using Western blots with previously undescribed antibodies, by a customized ELISA as well as by reporter assays. In addition, we performed an unbiased screen of 810 human miRNAs and identified the miR-15/16 family of genes at 13q14.3 as the strongest inducers of NF-kB activity. In summary, the tumor suppressor mechanism at 13q14.3 is a cluster of genes controlled by two lncRNA genes that are regulated by DNA-methylation and histone modifications and whose members all regulate NF-kB. Therefore, the tumor suppressor mechanism in 13q14.3 underlines the role both of epigenetic aberrations and of lncRNA genes

  6. Epigenetic Upregulation of lncRNAs at 13q14.3 in Leukemia Is Linked to the In Cis Downregulation of a Gene Cluster That Targets NF-kB

    Science.gov (United States)

    Claus, Rainer; Ruppel, Melanie; Tschuch, Cordula; Filarsky, Katharina; Idler, Irina; Zucknick, Manuela; Caudron-Herger, Maïwen; Oakes, Christopher; Fleig, Verena; Keklikoglou, Ioanna; Allegra, Danilo; Serra, Leticia; Thakurela, Sudhir; Tiwari, Vijay; Weichenhan, Dieter; Benner, Axel; Radlwimmer, Bernhard; Zentgraf, Hanswalter; Wiemann, Stefan; Rippe, Karsten; Plass, Christoph; Döhner, Hartmut; Lichter, Peter; Stilgenbauer, Stephan; Mertens, Daniel

    2013-01-01

    Non-coding RNAs are much more common than previously thought. However, for the vast majority of non-coding RNAs, the cellular function remains enigmatic. The two long non-coding RNA (lncRNA) genes DLEU1 and DLEU2 map to a critical region at chromosomal band 13q14.3 that is recurrently deleted in solid tumors and hematopoietic malignancies like chronic lymphocytic leukemia (CLL). While no point mutations have been found in the protein coding candidate genes at 13q14.3, they are deregulated in malignant cells, suggesting an epigenetic tumor suppressor mechanism. We therefore characterized the epigenetic makeup of 13q14.3 in CLL cells and found histone modifications by chromatin-immunoprecipitation (ChIP) that are associated with activated transcription and significant DNA-demethylation at the transcriptional start sites of DLEU1 and DLEU2 using 5 different semi-quantitative and quantitative methods (aPRIMES, BioCOBRA, MCIp, MassARRAY, and bisulfite sequencing). These epigenetic aberrations were correlated with transcriptional deregulation of the neighboring candidate tumor suppressor genes, suggesting a coregulation in cis of this gene cluster. We found that the 13q14.3 genes in addition to their previously known functions regulate NF-kB activity, which we could show after overexpression, siRNA–mediated knockdown, and dominant-negative mutant genes by using Western blots with previously undescribed antibodies, by a customized ELISA as well as by reporter assays. In addition, we performed an unbiased screen of 810 human miRNAs and identified the miR-15/16 family of genes at 13q14.3 as the strongest inducers of NF-kB activity. In summary, the tumor suppressor mechanism at 13q14.3 is a cluster of genes controlled by two lncRNA genes that are regulated by DNA-methylation and histone modifications and whose members all regulate NF-kB. Therefore, the tumor suppressor mechanism in 13q14.3 underlines the role both of epigenetic aberrations and of lncRNA genes in human

  7. The interaction between endogenous 30S ribosomal subunit protein S11 and Cucumber mosaic virus LS2b protein affects viral replication, infection and gene silencing suppressor activity.

    Directory of Open Access Journals (Sweden)

    Ruilin Wang

    Full Text Available Cucumber mosaic virus (CMV is a model virus for plant-virus protein interaction and mechanism research because of its wide distribution, high-level of replication and simple genome structure. The 2b protein is a multifunctional protein encoded by CMV that suppresses RNA silencing-based antiviral defense and contributes to CMV virulence in host plants. In this report, 12 host proteins were identified as CMV LS2b binding partners using the yeast two-hybrid screen system from the Arabidopsis thaliana cDNA library. Among the host proteins, 30S ribosomal subunit protein S11 (RPS11 was selected for further studies. The interaction between LS2b and full-length RPS11 was confirmed using the yeast two-hybrid system. Bimolecular fluorescence complementation (BIFC assays observed by confocal laser microscopy and Glutathione S-transferase (GST pull-down assays were used to verify the interaction between endogenous NbRPS11 and viral CMVLS2b both in vivo and in vitro. TRV-based gene silencing vector was used to knockdown NbRPS11 transcription, and immunoblot analysis revealed a decline in infectious viral RNA replication and a decrease in CMV infection in RPS11 down-regulated Nicotiana benthamiana plants. Thus, the knockdown of RPS11 likely inhibited CMV replication and accumulation. The gene silencing suppressor activity of CMV2b protein was reduced by the RPS11 knockdown. This study demonstrated that the function of viral LS2b protein was remarkably affected by the interaction with host RPS11 protein.

  8. Suppressors of RNA silencing encoded by tomato leaf curl

    Indian Academy of Sciences (India)

    Whitefly-transmitted begomoviruses infecting tomato crop code for five different proteins, ORF AC4, ORF AC2 and ORF AV2 in DNA-A component, ORF BV1 in DNA-B ... In the present study suppressor function of ORF C1 of three betasatellites Tomato leaf curl Bangalore betasatellite ToLCBB-[IN:Hess:08], Cotton leaf curl ...

  9. Alternative polyadenylation of tumor suppressor genes in small intestinal neuroendocrine tumors

    DEFF Research Database (Denmark)

    Rehfeld, Anders Aagaard; Plass, Mireya; Døssing, Kristina

    2014-01-01

    The tumorigenesis of small intestinal neuroendocrine tumors (SI-NETs) is poorly understood. Recent studies have associated alternative polyadenylation (APA) with proliferation, cell transformation, and cancer. Polyadenylation is the process in which the pre-messenger RNA is cleaved at a polyA site...... and a polyA tail is added. Genes with two or more polyA sites can undergo APA. This produces two or more distinct mRNA isoforms with different 3' untranslated regions. Additionally, APA can also produce mRNAs containing different 3'-terminal coding regions. Therefore, APA alters both the repertoire...... and the expression level of proteins. Here, we used high-throughput sequencing data to map polyA sites and characterize polyadenylation genome-wide in three SI-NETs and a reference sample. In the tumors, 16 genes showed significant changes of APA pattern, which lead to either the 3' truncation of mRNA coding regions...

  10. Fischer-344 Tp53-knockout rats exhibit a high rate of bone and brain neoplasia with frequent metastasis

    Directory of Open Access Journals (Sweden)

    Sarah A. Hansen

    2016-10-01

    Full Text Available Somatic mutations in the Tp53 tumor suppressor gene are the most commonly seen genetic alterations in cancer, and germline mutations in Tp53 predispose individuals to a variety of early-onset cancers. Development of appropriate translational animal models that carry mutations in Tp53 and recapitulate human disease are important for drug discovery, biomarker development and disease modeling. Current Tp53 mouse and rat models have significant phenotypic and genetic limitations, and often do not recapitulate certain aspects of human disease. We used a marker-assisted speed congenic approach to transfer a well-characterized Tp53-mutant allele from an outbred rat to the genetically inbred Fischer-344 (F344 rat to create the F344-Tp53tm1(EGFP-PacQly/Rrrc (F344-Tp53 strain. On the F344 genetic background, the tumor spectrum shifted, with the primary tumor types being osteosarcomas and meningeal sarcomas, compared to the hepatic hemangiosarcoma and lymphoma identified in the original outbred stock model. The Fischer model is more consistent with the early onset of bone and central nervous system sarcomas found in humans with germline Tp53 mutations. The frequency of osteosarcomas in F344-Tp53 homozygous and heterozygous animals was 57% and 36%, respectively. Tumors were highly representative of human disease radiographically and histologically, with tumors found primarily on long bones with frequent pulmonary metastases. Importantly, the rapid onset of osteosarcomas in this promising new model fills a current void in animal models that recapitulate human pediatric osteosarcomas and could facilitate studies to identify therapeutic targets.

  11. Variants in the ASB10 Gene Are Associated with Primary Open Angle Glaucoma

    NARCIS (Netherlands)

    Micheal, S.; Ayub, H.; Islam, F.; Siddiqui, S.N.; Khan, W.A.; Akhtar, F.; Qamar, R.; Khan, M.I.; Hollander, A.I. den

    2015-01-01

    BACKGROUND: Recently nonsynonymous coding variants in the ankyrin repeats and suppressor of cytokine signaling box-containing protein 10 (ASB10) gene were found to be associated with primary open angle glaucoma (POAG) in cohorts from Oregon and Germany, but this finding was not confirmed in an

  12. Gene expression patterns associated with p53 status in breast cancer

    International Nuclear Information System (INIS)

    Troester, Melissa A; Herschkowitz, Jason I; Oh, Daniel S; He, Xiaping; Hoadley, Katherine A; Barbier, Claire S; Perou, Charles M

    2006-01-01

    Breast cancer subtypes identified in genomic studies have different underlying genetic defects. Mutations in the tumor suppressor p53 occur more frequently in estrogen receptor (ER) negative, basal-like and HER2-amplified tumors than in luminal, ER positive tumors. Thus, because p53 mutation status is tightly linked to other characteristics of prognostic importance, it is difficult to identify p53's independent prognostic effects. The relation between p53 status and subtype can be better studied by combining data from primary tumors with data from isogenic cell line pairs (with and without p53 function). The p53-dependent gene expression signatures of four cell lines (MCF-7, ZR-75-1, and two immortalized human mammary epithelial cell lines) were identified by comparing p53-RNAi transduced cell lines to their parent cell lines. Cell lines were treated with vehicle only or doxorubicin to identify p53 responses in both non-induced and induced states. The cell line signatures were compared with p53-mutation associated genes in breast tumors. Each cell line displayed distinct patterns of p53-dependent gene expression, but cell type specific (basal vs. luminal) commonalities were evident. Further, a common gene expression signature associated with p53 loss across all four cell lines was identified. This signature showed overlap with the signature of p53 loss/mutation status in primary breast tumors. Moreover, the common cell-line tumor signature excluded genes that were breast cancer subtype-associated, but not downstream of p53. To validate the biological relevance of the common signature, we demonstrated that this gene set predicted relapse-free, disease-specific, and overall survival in independent test data. In the presence of breast cancer heterogeneity, experimental and biologically-based methods for assessing gene expression in relation to p53 status provide prognostic and biologically-relevant gene lists. Our biologically-based refinements excluded genes

  13. The Oncogenic STP Axis Promotes Triple-Negative Breast Cancer via Degradation of the REST Tumor Suppressor

    Directory of Open Access Journals (Sweden)

    Kristen L. Karlin

    2014-11-01

    Full Text Available Defining the molecular networks that drive breast cancer has led to therapeutic interventions and improved patient survival. However, the aggressive triple-negative breast cancer subtype (TNBC remains recalcitrant to targeted therapies because its molecular etiology is poorly defined. In this study, we used a forward genetic screen to discover an oncogenic network driving human TNBC. SCYL1, TEX14, and PLK1 (“STP axis” cooperatively trigger degradation of the REST tumor suppressor protein, a frequent event in human TNBC. The STP axis induces REST degradation by phosphorylating a conserved REST phospho-degron and bridging REST interaction with the ubiquitin-ligase βTRCP. Inhibition of the STP axis leads to increased REST protein levels and impairs TNBC transformation, tumor progression, and metastasis. Expression of the STP axis correlates with low REST protein levels in human TNBCs and poor clinical outcome for TNBC patients. Our findings demonstrate that the STP-REST axis is a molecular driver of human TNBC.

  14. Altered expression of the IQGAP1 gene in human lung cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.E.; Palmisano, W.A.; Lechner, J.F. [and others

    1995-12-01

    IQGAP1 is a GTPase activation protein that accelerates GTP hydrolysis by normal p21 ras proteins. Therefore, IQGAP1 could act as an upstream affector of p21 ras activity by convert in excess amounts of active GTP-21 ras to inactive GDP-21 ras. IQGAP1 displays extensive sequence similarity to the catalytic domain of all previously reported ras GAPs, including the tumor suppressor gene protein neurofibromatosis type 1 (NF1). It has been shown that abnormal NF1 protein cannot negatively regulate the activity of ras proteins in neuroblast cells. This observation supports the hypothesis that NF1 is a tumor suppressor gene whose product acts upstream of ras. IQGAP1 is primarily expressed in lung, where it may play a role similar to NF1 in regulating the activity of H-ras or K-ras proteins. IQGAP1 functions as other GAPs by controlling the activity of ras.

  15. Effect of bone marrow depletion on prostaglandin E-producing suppressor macrophages in mouse spleen

    International Nuclear Information System (INIS)

    Shibata, Y.; Volkman, A.

    1985-01-01

    The i.p. injection of Corynebacterium parvum (CP) into CBA/J mice effected increases in macrophage colony-forming cells (M-CFC) when spleen cells were cultured with L cell culture filtrate as a source of colony-stimulating factor. Significant increases in phagocytic macrophages (M phi) with Fc receptors for IgG2a and IgG2b immune complexes were additionally noted among the spleen cells in these mice. These M phi effectively inhibited Con A-induced lymphocyte proliferation, probably reflecting a 10-fold increase above normal controls in prostaglandin E to 47 ng/3 X 10(6) spleen cells/ml. To determine whether the suppressor M phi are immediate derivatives of splenic M-CFC, we tried to induce suppressor M phi by the injection of CP into mice depleted of bone marrow M-CFC by the earlier administration of the bone-seeking isotope, 89Sr. This procedure reduced M-CFC in the bone marrow to less than 1% of normal for more than 30 days. Monocytes in the blood fell to 5% of normal by day 10 and were 30% on day 30. Levels of resident peritoneal M phi showed relatively little change in this period. By contrast, splenic M-CFC increased to 20-fold higher than the cold 88Sr controls. CP-induced suppressor M phi activity, however, was sharply reduced in 89Sr marrow-depleted mice on day 10, despite the striking increase in M-CFC. There was a threefold increase in the number of phagocytic M phi binding IgG2a immune complexes, with no significant increase in IgG2b binding M phi. The kinetics of recovery of suppressor M phi activity showed that on days 20, 30, and 50 after 89Sr injection the activities reached 20%, 30%, and 70% of the cold control, respectively, and correlated with the recovery of significant levels of M-CFC in the bone marrow. Taken together, these observations suggest that splenic M-CFC are not an immediate source of PGE-suppressor M phi in vivo

  16. Subpopulation of human helper and suppressor T lymphocytes

    International Nuclear Information System (INIS)

    Venkataraman, M.; Levin, R.D.; Westerman, M.P.

    1983-01-01

    Mitogen driven differentiation of normal human mononuclear cells is a well-established model for the study of antibody synthesis in man. In certain rare individuals who are clinically normal, unfractionated mononuclear cells or a mixture of purified B plus T lymphocytes differentiate into immunoglobulin producing cells in response to purified protein derivative of tuberculin (PPD) but not in response to pokeweed mitogen (PWM). To evaluate this observation we have irradiated T cells from such individuals to eliminate naturally occurring suppressor T cell activity and then added the irradiated T cells back to autologous B cells before culture. The B cells then responded to PWM. The original PPD responses of cells from these individuals were now significantly reduced. Although, there was no difference between PWM nonresponders and responders in the number of OKT-8 positive cells, elimination of OKT-8 positive cells in the PWM nonresponders with OKT-8 monoclonal antibody and complement resulted in a significantly increased response to PWM. This study indicates that there are suppressor T cells which specifically inhibit B cell response to PWM without affecting the PPD response. These results also show that the helper T cells involved in the PWM response are radioresistant and those involved in the PPD response are radiosensitive

  17. Highly frequent promoter methylation and PIK3CA amplification in non-small cell lung cancer (NSCLC)

    International Nuclear Information System (INIS)

    Ji, Meiju; Guan, Haixia; Gao, Cuixia; Shi, Bingyin; Hou, Peng

    2011-01-01

    Lung cancer is the leading cause of cancer-related death worldwide. Genetic and epigenetic alterations have been identified frequently in lung cancer, such as promoter methylation, gene mutations and genomic amplification. However, the interaction between genetic and epigenetic events and their significance in lung tumorigenesis remains poorly understood. We determined the promoter methylation of 6 genes and PIK3CA amplification using quantitative methylation-specific PCR (Q-MSP) and real-time quantitative PCR, respectively, and explore the association of promoter methylation with PIK3CA amplification in a large cohort of clinically well-characterized non-small cell lung cancer (NSCLC). Highly frequent promoter methylation was observed in NSCLC. With 100% diagnostic specificity, excellent sensitivity, ranging from 45.8 to 84.1%, was found for each of the 6 genes. The promoter methylation was associated with histologic type. Methylation of CALCA, CDH1, DAPK1, and EVX2 was more common in squamous cell carcinomas (SCC) compared to adenocarcinomas (ADC). Conversely, there was a trend toward a higher frequency of RASSF1A methylation in ADC than SCC. In addition, PIK3CA amplification was frequently found in NSCLC, and was associated with certain clinicopathologic features, such as smoking history, histologic type and pleural indentation. Importantly, aberrant promoter methylation of certain genes was significantly associated with PIK3CA amplification. Our data showed highly frequent promoter methylation and PIK3CA amplification in Chinese NSCLC population, and first demonstrated the associations of gene methylation with PIK3CA amplification, suggesting that these epigenetic events may be a consequence of overactivation of PI3K/Akt pathway

  18. Genomic loss of tumor suppressor miRNA-204 promotes cancer cell migration and invasion by activating AKT/mTOR/Rac1 signaling and actin reorganization.

    Directory of Open Access Journals (Sweden)

    J Saadi Imam

    Full Text Available Increasing evidence suggests that chromosomal regions containing microRNAs are functionally important in cancers. Here, we show that genomic loci encoding miR-204 are frequently lost in multiple cancers, including ovarian cancers, pediatric renal tumors, and breast cancers. MiR-204 shows drastically reduced expression in several cancers and acts as a potent tumor suppressor, inhibiting tumor metastasis in vivo when systemically delivered. We demonstrated that miR-204 exerts its function by targeting genes involved in tumorigenesis including brain-derived neurotrophic factor (BDNF, a neurotrophin family member which is known to promote tumor angiogenesis and invasiveness. Analysis of primary tumors shows that increased expression of BDNF or its receptor tropomyosin-related kinase B (TrkB parallel a markedly reduced expression of miR-204. Our results reveal that loss of miR-204 results in BDNF overexpression and subsequent activation of the small GTPase Rac1 and actin reorganization through the AKT/mTOR signaling pathway leading to cancer cell migration and invasion. These results suggest that microdeletion of genomic loci containing miR-204 is directly linked with the deregulation of key oncogenic pathways that provide crucial stimulus for tumor growth and metastasis. Our findings provide a strong rationale for manipulating miR-204 levels therapeutically to suppress tumor metastasis.

  19. Epigenetic Silencing of Eyes Absent 4 Gene by Acute Myeloid Leukemia 1-Eight-twenty-one Oncoprotein Contributes to Leukemogenesis in t(8;21 Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Sai Huang

    2016-01-01

    Conclusions: Our study identified EYA4 gene as targets for AML1-ETO and indicated it as a novel tumor suppressor gene. In addition, we provided evidence that EYA4 gene might be a novel therapeutic target and a potential candidate for treating AML1-ETO+ t (8;21 AML.

  20. 15-Hydroxyprostaglandin dehydrogenase is an in vivo suppressor of colon tumorigenesis.

    Science.gov (United States)

    Myung, Seung-Jae; Rerko, Ronald M; Yan, Min; Platzer, Petra; Guda, Kishore; Dotson, Angela; Lawrence, Earl; Dannenberg, Andrew J; Lovgren, Alysia Kern; Luo, Guangbin; Pretlow, Theresa P; Newman, Robert A; Willis, Joseph; Dawson, Dawn; Markowitz, Sanford D

    2006-08-08

    15-Hydroxyprostaglandin dehydrogenase (15-PGDH) is a prostaglandin-degrading enzyme that is highly expressed in normal colon mucosa but is ubiquitously lost in human colon cancers. Herein, we demonstrate that 15-PGDH is active in vivo as a highly potent suppressor of colon neoplasia development and acts in the colon as a required physiologic antagonist of the prostaglandin-synthesizing activity of the cyclooxygenase 2 (COX-2) oncogene. We first show that 15-PGDH gene knockout induces a marked 7.6-fold increase in colon tumors arising in the Min (multiple intestinal neoplasia) mouse model. Furthermore, 15-PGDH gene knockout abrogates the normal resistance of C57BL/6J mice to colon tumor induction by the carcinogen azoxymethane (AOM), conferring susceptibility to AOM-induced adenomas and carcinomas in situ. Susceptibility to AOM-induced tumorigenesis is mediated by a marked induction of dysplasia, proliferation, and cyclin D1 expression throughout microscopic aberrant crypt foci arising in 15-PGDH null colons and is concomitant with a doubling of prostaglandin E(2) in 15-PGDH null colonic mucosa. A parallel role for 15-PGDH loss in promoting the earliest steps of colon neoplasia in humans is supported by our finding of a universal loss of 15-PGDH expression in microscopic colon adenomas recovered from patients with familial adenomatous polyposis, including adenomas as small as a single crypt. These models thus delineate the in vivo significance of 15-PGDH-mediated negative regulation of the COX-2 pathway and moreover reveal the particular importance of 15-PGDH in opposing the neoplastic progression of colonic aberrant crypt foci.

  1. Maternally Expressed Gene 3, an imprinted non-coding RNA gene, is associated with meningioma pathogenesis and progression

    Science.gov (United States)

    Zhang, Xun; Gejman, Roger; Mahta, Ali; Zhong, Ying; Rice, Kimberley A.; Zhou, Yunli; Cheunsuchon, Pornsuk; Louis, David N.; Klibanski, Anne

    2010-01-01

    Meningiomas are common tumors, representing 15-25% of all central nervous system tumors. NF2 gene inactivation on chromosome 22 has been shown as an early event in tumorigenesis; however, few factors underlying tumor growth and progression have been identified. Chromosomal abnormalities of 14q32 are often associated with meningioma pathogenesis and progression; therefore it has been proposed that an as yet unidentified tumor suppressor is present at this locus. MEG3 is an imprinted gene located at 14q32 that encodes a non-coding RNA with an anti-proliferative function. We found that MEG3 mRNA is highly expressed in normal arachnoidal cells. However, MEG3 is not expressed in the majority of human meningiomas or the human meningioma cell lines IOMM-Lee and CH157-MN. There is a strong association between loss of MEG3 expression and tumor grade. Allelic loss at the MEG3 locus is also observed in meningiomas, with increasing prevalence in higher grade tumors. In addition, there is an increase in CpG methylation within the promoter and the imprinting control region of MEG3 gene in meningiomas. Functionally, MEG3 suppresses DNA synthesis in both IOMM-Lee and CH157-MN cells by approximately 60% in BrdU incorporation assays. Colony-forming efficiency assays show that MEG3 inhibits colony formation in CH157-MN cells by approximately 80%. Furthermore, MEG3 stimulates p53-mediated transactivation in these cell lines. Therefore, these data are consistent with the hypothesis that MEG3, which encodes a non-coding RNA, may be a tumor suppressor gene at chromosome 14q32 involved in meningioma progression via a novel mechanism. PMID:20179190

  2. The Putative PAX8/PPARγ Fusion Oncoprotein Exhibits Partial Tumor Suppressor Activity through Up-Regulation of Micro-RNA-122 and Dominant-Negative PPARγ Activity.

    Science.gov (United States)

    Reddi, Honey V; Madde, Pranathi; Milosevic, Dragana; Hackbarth, Jennifer S; Algeciras-Schimnich, Alicia; McIver, Bryan; Grebe, Stefan K G; Eberhardt, Norman L

    2011-01-01

    In vitro studies have demonstrated that the PAX8/PPARγ fusion protein (PPFP), which occurs frequently in follicular thyroid carcinomas (FTC), exhibits oncogenic activity. However, paradoxically, a meta-analysis of extant tumor outcome studies indicates that 68% of FTC-expressing PPFP are minimally invasive compared to only 32% of those lacking PPFP (χ(2) = 6.86, P = 0.008), suggesting that PPFP favorably impacts FTC outcomes. In studies designed to distinguish benign thyroid neoplasms from thyroid carcinomas, the previously identified tumor suppressor miR-122, a major liver micro-RNA (miR) that is decreased in hepatocellular carcinoma, was increased 8.9-fold (P negative PPARγ mutant in WRO cells was less effective than PPFP at inhibiting xenograft tumor progression (1.8-fold [P negative PPARγ activity. Up-regulation of miR-122 negatively regulates ADAM-17, a known downstream target, in thyroid cells, suggesting an antiangiogenic mechanism in thyroid carcinoma. This latter inference is directly supported by reduced CD-31 expression in WRO xenografts expressing PPFP, miR-122, and DN-PPARγ. We conclude that, in addition to its apparent oncogenic potential in vitro, PPFP exhibits paradoxical tumor suppressor activity in vivo, mediated by multiple mechanisms including up-regulation of miR-122 and dominant-negative inhibition of PPARγ activity.

  3. Molecular Cloning, Characterization, and Expression of MiSOC1: A Homolog of the Flowering Gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 from Mango (Mangifera indica L)

    Science.gov (United States)

    Wei, Junya; Liu, Debing; Liu, Guoyin; Tang, Jie; Chen, Yeyuan

    2016-01-01

    MADS-box transcription factor plays a crucial role in plant development, especially controlling the formation and development of floral organs. Mango (Mangifera indica L) is an economically important fruit crop, but its molecular control of flowering is largely unknown. To better understand the molecular basis of flowering regulation in mango, we isolated and characterized the MiSOC1, a putative mango orthologs for the Arabidopsis SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1/AGAMOUS-LIKE 20 (SOC1/AGL20) with homology-based cloning and RACE. The full-length cDNA (GenBank accession No.: KP404094) is 945 bp in length including a 74 bp long 5′ UTR and a 189 bp long 3′ UTR and the open reading frame was 733 bps, encoding 223 amino acids with molecular weight 25.6 kD. Both sequence alignment and phylogenetic analysis all indicated that deduced protein contained a conservative MADS-box and semi-conservative K domain and belonged to the SOC1/TM3 subfamily of the MADS-box family. Quantitative real-time PCR was performed to investigate the expression profiles of MiSOC1 gene in different tissues/organs including root, stem, leaves, flower bud, and flower. The result indicated MiSOC1 was widely expressed at different levels in both vegetative and reproductive tissues/organs with the highest expression level in the stems’ leaves and inflorescences, low expression in roots and flowers. The expression of MiSOC1 in different flower developmental stages was different while same tissue –specific pattern among different varieties. In addition, MiSOC1 gene expression was affect by ethephon while high concentration ethephon inhibit the expression of MiSOC1. Overexpression of MiSOC1 resulted in early flowering in Arabidopsis. In conclusion, these results suggest that MiSOC1 may act as induce flower function in mango. PMID:27965680

  4. Molecular Cloning, Characterization, and Expression of MiSOC1: A Homolog of the Flowering Gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 from Mango (Mangifera indica L).

    Science.gov (United States)

    Wei, Junya; Liu, Debing; Liu, Guoyin; Tang, Jie; Chen, Yeyuan

    2016-01-01

    MADS-box transcription factor plays a crucial role in plant development, especially controlling the formation and development of floral organs. Mango ( Mangifera indica L) is an economically important fruit crop, but its molecular control of flowering is largely unknown. To better understand the molecular basis of flowering regulation in mango, we isolated and characterized the MiSOC1, a putative mango orthologs for the Arabidopsis SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1/AGAMOUS-LIKE 20 (SOC1/AGL20) with homology-based cloning and RACE. The full-length cDNA (GenBank accession No.: KP404094) is 945 bp in length including a 74 bp long 5' UTR and a 189 bp long 3' UTR and the open reading frame was 733 bps, encoding 223 amino acids with molecular weight 25.6 kD. Both sequence alignment and phylogenetic analysis all indicated that deduced protein contained a conservative MADS-box and semi-conservative K domain and belonged to the SOC1/TM3 subfamily of the MADS-box family. Quantitative real-time PCR was performed to investigate the expression profiles of MiSOC1 gene in different tissues/organs including root, stem, leaves, flower bud, and flower. The result indicated MiSOC1 was widely expressed at different levels in both vegetative and reproductive tissues/organs with the highest expression level in the stems' leaves and inflorescences, low expression in roots and flowers. The expression of MiSOC1 in different flower developmental stages was different while same tissue -specific pattern among different varieties. In addition, MiSOC1 gene expression was affect by ethephon while high concentration ethephon inhibit the expression of MiSOC1. Overexpression of MiSOC1 resulted in early flowering in Arabidopsis . In conclusion, these results suggest that MiSOC1 may act as induce flower function in mango.

  5. History of myeloid-derived suppressor cells.

    Science.gov (United States)

    Talmadge, James E; Gabrilovich, Dmitry I

    2013-10-01

    Tumour-induced granulocytic hyperplasia is associated with tumour vasculogenesis and escape from immunity via T cell suppression. Initially, these myeloid cells were identified as granulocytes or monocytes; however, recent studies have revealed that this hyperplasia is associated with populations of multipotent progenitor cells that have been identified as myeloid-derived suppressor cells (MDSCs). The study of MDSCs has provided a wealth of information regarding tumour pathobiology, has extended our understanding of neoplastic progression and has modified our approaches to immune adjuvant therapy. In this Timeline article, we discuss the history of MDSCs, their influence on tumour progression and metastasis, and the crosstalk between tumour cells, MDSCs and the host macroenvironment.

  6. Molecular Genetics and Gene Therapy in Esophageal Cancer: a Review Article

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Noori Daloii Ph.D.

    2011-06-01

    Full Text Available Background: With approximately 386,000 deaths per year, esophageal cancer is the 6th most common cause of death due to cancer in the world. This cancer, like any other cancer, is the outcome of genetic alterations or environmental factors such as tobacco smoke and gastro-esophageal reflux. Tobacco smoking is a major etiologic factor for esophageal squamous cell carcinoma in western countries, and it increases the risk by approximately 3 to 5 folds. Chronic gastro-esophageal reflux usually leads to the replacement of squamous mucosa by intestinal-type Barrett’s metaplastic mucosa which is considered the most important factor causing esophageal adenocarcinoma. In contrast to esophageal adenocarcinoma, different risk factors and mechanisms, such as mutations in oncogenes and tumor suppressor genes, play an important role in causing esophageal squamous cell carcinoma. Molecular studies on esophageal cancers have revealed frequent genetic abnormalities in esophageal squamous cell carcinoma and adenocarcinoma, including altered expression of p53, p16, cyclin D1, EGFR, E-cadherin, COX-2, iNOS, RARs, Rb, hTERT, p21, APC, c-MYC, VEGF, TGT-α and NF-κB. Many studies have focused on the role of different polymorphisms such as aldehyde dehydrogenase 2 and alcohol dehydrogenase 2 in causing esophageal cancer. Different agents including bestatin, curcumin, black raspberries, 5-lipoxygenase (LOX and COX-2 inhibitors have been found to play a role in inhibiting esophageal carcinogenesis. Different gene therapy approaches including p53 and p21WAF1 replacement gene therapies and therapy by suicide genes have also been experimented. Moreover, efforts have been made to use nanotechnology and aptamer technology in this regard.

  7. Enumerating all maximal frequent subtrees in collections of phylogenetic trees.

    Science.gov (United States)

    Deepak, Akshay; Fernández-Baca, David

    2014-01-01

    A common problem in phylogenetic analysis is to identify frequent patterns in a collection of phylogenetic trees. The goal is, roughly, to find a subset of the species (taxa) on which all or some significant subset of the trees agree. One popular method to do so is through maximum agreement subtrees (MASTs). MASTs are also used, among other things, as a metric for comparing phylogenetic trees, computing congruence indices and to identify horizontal gene transfer events. We give algorithms and experimental results for two approaches to identify common patterns in a collection of phylogenetic trees, one based on agreement subtrees, called maximal agreement subtrees, the other on frequent subtrees, called maximal frequent subtrees. These approaches can return subtrees on larger sets of taxa than MASTs, and can reveal new common phylogenetic relationships not present in either MASTs or the majority rule tree (a popular consensus method). Our current implementation is available on the web at https://code.google.com/p/mfst-miner/. Our computational results confirm that maximal agreement subtrees and all maximal frequent subtrees can reveal a more complete phylogenetic picture of the common patterns in collections of phylogenetic trees than maximum agreement subtrees; they are also often more resolved than the majority rule tree. Further, our experiments show that enumerating maximal frequent subtrees is considerably more practical than enumerating ordinary (not necessarily maximal) frequent subtrees.

  8. Strategies in Gene Therapy for Glioblastoma

    International Nuclear Information System (INIS)

    Kwiatkowska, Aneta; Nandhu, Mohan S.; Behera, Prajna; Chiocca, E. Antonio; Viapiano, Mariano S.

    2013-01-01

    Glioblastoma (GBM) is the most aggressive form of brain cancer, with a dismal prognosis and extremely low percentage of survivors. Novel therapies are in dire need to improve the clinical management of these tumors and extend patient survival. Genetic therapies for GBM have been postulated and attempted for the past twenty years, with variable degrees of success in pre-clinical models and clinical trials. Here we review the most common approaches to treat GBM by gene therapy, including strategies to deliver tumor-suppressor genes, suicide genes, immunomodulatory cytokines to improve immune response, and conditionally-replicating oncolytic viruses. The review focuses on the strategies used for gene delivery, including the most common and widely used vehicles (i.e., replicating and non-replicating viruses) as well as novel therapeutic approaches such as stem cell-mediated therapy and nanotechnologies used for gene delivery. We present an overview of these strategies, their targets, different advantages, and challenges for success. Finally, we discuss the potential of gene therapy-based strategies to effectively attack such a complex genetic target as GBM, alone or in combination with conventional therapy

  9. Strategies in Gene Therapy for Glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowska, Aneta; Nandhu, Mohan S.; Behera, Prajna; Chiocca, E. Antonio; Viapiano, Mariano S., E-mail: mviapiano@partners.org [Department of Neurosurgery, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 (United States)

    2013-10-22

    Glioblastoma (GBM) is the most aggressive form of brain cancer, with a dismal prognosis and extremely low percentage of survivors. Novel therapies are in dire need to improve the clinical management of these tumors and extend patient survival. Genetic therapies for GBM have been postulated and attempted for the past twenty years, with variable degrees of success in pre-clinical models and clinical trials. Here we review the most common approaches to treat GBM by gene therapy, including strategies to deliver tumor-suppressor genes, suicide genes, immunomodulatory cytokines to improve immune response, and conditionally-replicating oncolytic viruses. The review focuses on the strategies used for gene delivery, including the most common and widely used vehicles (i.e., replicating and non-replicating viruses) as well as novel therapeutic approaches such as stem cell-mediated therapy and nanotechnologies used for gene delivery. We present an overview of these strategies, their targets, different advantages, and challenges for success. Finally, we discuss the potential of gene therapy-based strategies to effectively attack such a complex genetic target as GBM, alone or in combination with conventional therapy.

  10. Metformin inhibits epithelial–mesenchymal transition in prostate cancer cells: Involvement of the tumor suppressor miR30a and its target gene SOX4

    International Nuclear Information System (INIS)

    Zhang, Jing; Shen, Chengwu; Wang, Lin; Ma, Quanping; Xia, Pingtian; Qi, Mei; Yang, Muyi; Han, Bo

    2014-01-01

    Highlights: • Metformin inhibits TGF-β-induced EMT in prostate cancer (PCa) cells. • Metformin upregulates tumor suppressor miR30a and downregulates SOX4 in PCa cells. • SOX4 is a target gene of miR30a. - Abstract: Tumor metastasis is the leading cause of mortality and morbidity of prostate cancer (PCa) patients. Epithelial–mesenchymal transition (EMT) plays a critical role in cancer progression and metastasis. Recent evidence suggested that diabetic patients treated with metformin have lower PCa risk and better prognosis. This study was aimed to investigate the effects of metformin on EMT in PCa cells and the possible microRNA (miRNA)-based mechanisms. MiRNAs have been shown to regulate various processes of cancer metastasis. We herein showed that metformin significantly inhibits proliferation of Vcap and PC-3 cells, induces G0/G1 cell cycle arrest and inhibits invasiveness and motility capacity of Vcap cells. Metformin could inhibit TGF-β-induced EMT in Vcap cells, as manifested by inhibition of the increase of N-cadherin (p = 0.013), Vimentin (p = 0.002) and the decrease of E-cadherin (p = 0.0023) and β-catenin (p = 0.034) at mRNA and protein levels. Notably, we demonstrated significant upregulation of miR30a levels by metformin (P < 0.05) and further experiments indicated that miR30a significantly inhibits proliferation and EMT process of Vcap cells. Interestingly, we identified that SOX4, a previously reported oncogenic transcriptional factor and modulator of EMT, is a direct target gene of miR30a. Finally, we screened the expression of miR30a and SOX4 in 84 PCa cases with radical prostatectomy. Of note, SOX4 overexpression is significantly associated with decreased levels of miR30a in PCa cases. In all, our study suggested that inhibition of EMT by metformin in PCa cells may involve upregulation of miR30a and downregulation of SOX4

  11. NGX6 gene mediated by promoter methylation as a potential molecular marker in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Shen Shourong

    2010-04-01

    Full Text Available Abstract Background Nasopharyngeal carcinoma associated gene 6 (NGX6 is down-regulated in most colon cancer cell lines and tumor tissues when compared with their normal tissue samples. As a novel suppress tumor gene, it could inhibit colon cancer cell growth and cell cycle progression. However, little is known about the transcriptional mechanisms controlling NGX6 gene expression. Recent findings suggest that epigenetic inactivation of multiple tumor suppressor genes plays an important role in the tumorigenesis of colorectal carcinoma (CRC. In this study, we explored the role of DNA methylation in regulation of NGX6 transcription. Methods In the present study, we cloned the NGX6 promoter with characteristics of a CpG island by luciferase reporter assay. Then, the CpG methylation status around the NGX6 promoter region in colon cancer cell lines and colorectal tumor tissues was examined by methylation-specific PCR and bisulfite DNA sequencing. Finally, 5-Aza-2'-deoxycytidine (5-Aza-dC treatment was used to confirm the correlation between NGX6 promoter methylation and its gene inactivation. Results The sequence spanning positions -157 to +276 was identified as the NGX6 promoter, in which no canonical TATA boxes were found, while two CAAT boxes and GC boxes were discovered. Methylation status was observed more frequently in 40 colorectal cancer samples than in 40 adjacent normal mucosa samples (18/40 versus 7/40; P Conclusions Down-regulation of NGX6 gene is related to the promoter methylation. DNA methylation of NGX6 promoter might be a potential molecular marker for diagnosis or prognosis, or serve as a therapeutic target.

  12. Clinical impact of the immunome in lymphoid malignancies: the role of Myeloid-Derived Suppressor Cells

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    Calogero eVetro

    2015-05-01

    Full Text Available The better definition of the mutual sustainment between neoplastic cells and immune system has been translated from the bench to the bedside acquiring value as prognostic factor. Additionally, it represents a promising tool for improving therapeutic strategies. In this context, myeloid-derived suppressor cells have gained a central role in tumor developing with consequent therapeutic implications. In this review, we will focus on the biological and clinical impact of the study of myeloid-derived suppressor cells in the settings of lymphoid malignancies.

  13. The milk protein α-casein functions as a tumor suppressor via activation of STAT1 signaling, effectively preventing breast cancer tumor growth and metastasis

    Science.gov (United States)

    Bonuccelli, Gloria; Castello-Cros, Remedios; Capozza, Franco; Martinez-Outschoorn, Ubaldo E.; Lin, Zhao; Tsirigos, Aristotelis; Xuanmao, Jiao; Whitaker-Menezes, Diana; Howell, Anthony; Lisanti, Michael P.; Sotgia, Federica

    2012-01-01

    Here, we identified the milk protein α-casein as a novel suppressor of tumor growth and metastasis. Briefly, Met-1 mammary tumor cells expressing α-casein showed a ~5-fold reduction in tumor growth and a near 10-fold decrease in experimental metastasis. To identify the molecular mechanism(s), we performed genome-wide transcriptional profiling. Interestingly, our results show that α-casein upregulates gene transcripts associated with interferon/STAT1 signaling and downregulates genes associated with “stemness.” These findings were validated by immunoblot and FACS analysis, which showed the upregulation and hyperactivation of STAT1 and a decrease in the number of CD44(+) “cancer stem cells.” These gene signatures were also able to predict clinical outcome in human breast cancer patients. Thus, we conclude that a lactation-based therapeutic strategy using recombinant α-casein would provide a more natural and non-toxic approach to the development of novel anticancer therapies. PMID:23047602

  14. Insulin dependent diabetes mellitus (IDDM) and autoimmune thyroiditis in a boy with a ring chromosome 18: additional evidence of autoimmunity or IDDM gene(s) on chromosome 18

    OpenAIRE

    Dacou-Voutetakis, C; Sertedaki, A; Maniatis-Christid..., M; Sarri, C; Karadima, G; Petersen, M; Xaidara, A; Kanariou, M; Nicolaidou, P

    1999-01-01

    A 4 year 3 month old boy with insulin dependent diabetes mellitus (IDDM), autoimmune thyroiditis, slight mental retardation, facial dysmorphism, and a de novo ring chromosome 18 (deletion 18q22.3-18qter) is described. This unique association of defects could represent a chance association. Alternatively, the clinical features could be the result of the chromosomal aberration. If so, one could speculate that a gene or genes on chromosome 18 might act as a suppressor or activator of the autoimm...

  15. Identification of a maize chlorotic dwarf virus silencing suppressor protein

    Science.gov (United States)

    Maize chlorotic dwarf virus (MCDV), a member of the genus Waikavirus, family Secoviridae, has a 11784 nt (+)ssRNA genome that encodes a 389 kDa proteolytically processed polyprotein. We show that an N-terminal 78kDa polyprotein (R78) has silencing suppressor activity, that it is cleaved by the viral...

  16. MiR-142-3p Functions as a Potential Tumor Suppressor in Human Osteosarcoma by Targeting HMGA1

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    Guoxing Xu

    2014-04-01

    Full Text Available Background/Aims: Mounting evidence has shown that aberrant expression of miRNAs correlates with human cancers, and that miRNAs can function as tumor suppressors or oncogenes. Here, we investigated the role and mechanism of miR-142-3p in human osteosarcoma. Methods: We used quantitative real-time RT-PCR to measure the expression of miR-142-3p in human osteosarcoma cell lines and tissues. The roles of miR-142-3p in osteosarcoma development were studied using cultured HOS, MG63 and Saos-2 cells and tumor xenograft analyses in nude mice; their target genes were also investigated. Results: We found that miR-142-3p was significantly downregulated in osteosarcoma cell lines and clinical specimens. Overexpression of miR-142-3p suppressed osteosarcoma cell proliferation, migration and invasion, whereas miR-142-3p knockdown increased these parameters. The xenograft mouse model also revealed the suppressive effect of miR-142-3p on tumor growth. High mobility group AT-hook 1 (HMGA1 was identified as a target of miR-142-3p. Downregulation of HMGA1 induced effects on osteosarcoma cell lines similar to those induced by miR-142-3p. In contrast, restoration of HMGA1 abrogated the effects induced by miR-142-3p up-regulation. Conclusion: These results indicated that miR-142-3p may function as a tumor suppressor by targeting HMGA1 in osteosarcoma.

  17. Speckle-type POZ (pox virus and zinc finger protein) protein gene deletion in ovarian cancer: Fluorescence in situ hybridization analysis of a tissue microarray.

    Science.gov (United States)

    Hu, Xiaoyu; Yang, Zhu; Zeng, Manman; Liu, Y I; Yang, Xiaotao; Li, Yanan; Li, X U; Yu, Qiubo

    2016-07-01

    The aim of the present study was to investigate the status of speckle-type POZ (pox virus and zinc finger protein) protein (SPOP) gene located on chromosome 17q21 in ovarian cancer (OC). The present study evaluated a tissue microarray, which contained 90 samples of ovarian cancer and 10 samples of normal ovarian tissue, using fluorescence in situ hybridization (FISH). FISH is a method where a SPOP-specific DNA red fluorescence probe was used for the experimental group and a centromere-specific DNA green fluorescence probe for chromosome 17 was used for the control group. The present study demonstrated that a deletion of the SPOP gene was observed in 52.27% (46/88) of the ovarian cancer tissues, but was not identified in normal ovarian tissues. Simultaneously, monosomy 17 was frequently identified in the ovarian cancer tissues, but not in the normal ovarian tissues. Furthermore, the present data revealed that the ovarian cancer histological subtype and grade were significantly associated with a deletion of the SPOP gene, which was assessed by the appearance of monosomy 17 in the ovarian cancer samples; the deletion of the SPOP gene was observed in a large proportion of serous epithelial ovarian cancer (41/61; 67.21%), particularly in grade 3 (31/37; 83.78%). In conclusion, deletion of the SPOP gene on chromosome 17 in ovarian cancer samples, which results from monosomy 17, indicates that the SPOP gene may serve as a tumor suppressor gene in ovarian cancer.

  18. A mutation at IVS1 + 5 of the von Hippel-Lindau gene resulting in intron retention in transcripts is not pathogenic in a patient with a tongue cancer?: case report

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    Asakawa Takeshi

    2012-03-01

    Full Text Available Abstract Background Von Hippel-Lindau disease (VHL is a dominantly inherited familial cancer syndrome predisposing the patient to a variety of malignant and benign neoplasms, most frequently hemangioblastoma, renal cell carcinoma, pheochromocytoma, and pancreatic tumors. VHL is caused by mutations of the VHL tumor suppressor gene on the short arm of chromosome 3, and clinical manifestations develop if both alleles are inactivated according to the two-hit hypothesis. VHL mutations are more frequent in the coding region and occur occasionally in the splicing region of the gene. Previously, we reported that the loss of heterozygosity (LOH of the VHL gene is common in squamous cell carcinoma tissues of the tongue. Case Presentation We describe a case of squamous cell carcinoma in the tongue caused by a point mutation in the splicing region of the VHL gene and discuss its association with VHL disease. Sequence analysis of DNA extracted from the tumor and peripheral blood of the patient with squamous cell carcinoma revealed a heterozygous germline mutation (c. 340 + 5 G > C in the splice donor sequence in intron 1 of the VHL gene. RT-PCR analysis of the exon1/intron1 junction in RNA from tumor tissue detected an unspliced transcript. Analysis of LOH using a marker with a heterozygous mutation of nucleotides (G or C revealed a deletion of the mutant C allele in the carcinoma tissues. Conclusions The fifth nucleotide G of the splice donor site of the VHL gene is important for the efficiency of splicing at that site. The development of tongue cancer in this patient was not associated with VHL disease because the mutation occurred in only a single allele of the VHL gene and that allele was deleted in tumor cells.

  19. Suppressor of cytokine signaling 1 expression during LPS-induced inflammation and bone loss in rats

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    João Antonio Chaves de SOUZA

    2017-10-01

    Full Text Available Abstract This study aimed to characterize the dynamics of suppressor of cytokine signaling (SOCS1 expression in a rat model of lipopolysaccharide-induced periodontitis. Wistar rats in the experimental groups were injected three times/week with LPS from Escherichia coli on the palatal aspect of the first molars, and control animals were injected with vehicle (phosphate-buffered saline. Animals were sacrificed 7, 15, and 30 days after the first injection to analyze inflammation (stereometric analysis, bone loss (macroscopic analysis, gene expression (qRT-PCR, and protein expression/activation (Western blotting. The severity of inflammation and bone loss associated with LPS-induced periodontitis increased from day 7 to day 15, and it was sustained through day 30. Significant (p < 0.05 increases in SOCS1, RANKL, OPG, and IFN-γ gene expression were observed in the experimental group versus the control group at day 15. SOCS1 protein expression and STAT1 and NF-κB activation were increased throughout the 30-day experimental period. Gingival tissues affected by experimental periodontitis express SOCS1, indicating that this protein may potentially downregulate signaling events involved in inflammatory reactions and bone loss and thus may play a relevant role in the development and progression of periodontal disease.

  20. Chronic ultraviolet exposure-induced p53 gene alterations in sencar mouse skin carcinogenesis model

    International Nuclear Information System (INIS)

    Tong, Ying; Smith, M.A.; Tucker, S.B.

    1997-01-01

    Alterations of the tumor suppressor gene p53 have been found in ultraviolet radiation (UVR) related human skin cancers and in UVR-induced murine skin tumors. However, links between p53 gene alterations and the stages of carcinogenesis induced by UVR have not been clearly defined. We established a chronic UVR exposure-induced Sencar mouse skin carcinogenesis model to determine the frequency of p53 gene alterations in different stages of carcinogenesis, including UV-exposed skin, papillomas, squamous-cell carcinomas (SCCs), and malignant spindle-cell tumors (SCTs). A high incidence of SCCs and SCTs were found in this model. Positive p53 nuclear staining was found in 10137 (27%) of SCCs and 12124 (50%) of SCTs, but was not detected in normal skin or papillomas. DNA was isolated from 40 paraffin-embedded normal skin, UV-exposed skin, and tumor sections. The p53 gene (exons 5 and 6) was amplified from the sections by using nested polymerase chain reaction (PCR). Subsequent single-strand conformation polymorphism (SSCP) assay and sequencing analysis revealed one point mutation in exon 6 (coden 193, C → A transition) from a UV-exposed skin sample, and seven point mutations in exon 5 (codens 146, 158, 150, 165, and 161, three C → T, two C → A, one C → G, and one A → T transition, respectively) from four SCTs, two SCCs and one UV-exposed skin sample. These experimental results demonstrate that alterations in the p53 gene are frequent events in chronic UV exposure-induced SCCs and later stage SCTs in Sencar mouse skin. 40 refs., 5 figs., 1 tab

  1. Involvement of PSMD10, CDK4, and Tumor Suppressors in Development of Intrahepatic Cholangiocarcinoma of Syrian Golden Hamsters Induced by Clonorchis sinensis and N-Nitrosodimethylamine.

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    Md Hafiz Uddin

    Full Text Available Clonorchis sinensis is a group-I bio-carcinogen for cholangiocarcinoma (CCA. Although the epidemiological evidence links clonorchiasis and CCA, the underlying molecular mechanism involved in this process is poorly understood. In the present study, we investigated expression of oncogenes and tumor suppressors, including PSMD10, CDK4, p53 and RB in C. sinensis induced hamster CCA model.Different histochemical/immunohistochemical techniques were performed to detect CCA in 4 groups of hamsters: uninfected control (Ctrl., infected with C. sinensis (Cs, ingested N-nitrosodimethylamine (NDMA, and both Cs infected and NDMA introduced (Cs+NDMA. The liver tissues from all groups were analyzed for gene/protein expressions by quantitative PCR (qPCR and western blotting.CCA was observed in all hamsters of Cs+NDMA group with well, moderate, and poorly differentiated types measured in 21.8% ± 1.5%, 13.3% ± 1.3%, and 10.8% ± 1.3% of total tissue section areas respectively. All CCA differentiations progressed in a time dependent manner, starting from the 8th week of infection. CCA stroma was characterized with increased collagen type I, mucin, and proliferative cell nuclear antigen (PCNA. The qPCR analysis showed PSMD10, CDK4 and p16INK4 were over-expressed, whereas p53 was under-expressed in the Cs+NDMA group. We observed no change in RB1 at mRNA level but found significant down-regulation of RB protein. The apoptosis related genes, BAX and caspase 9 were found downregulated in the CCA tissue. Gene/protein expressions were matched well with the pathological changes of different groups except the NDMA group. Though the hamsters in the NDMA group showed no marked pathological lesions, we observed over-expression of Akt/PKB and p53 genes proposing molecular interplay in this group which might be related to the CCA initiation in this animal model.The present findings suggest that oncogenes, PSMD10 and CDK4, and tumor suppressors, p53 and RB, are involved in the

  2. BIOLOGICAL FUNCTION OF TOMBUSVIRUS-ENCODED SUPPRESSOR OF RNA SILENCING IN PLANTS

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    Omarov R.T.

    2012-08-01

    Full Text Available RNA interference (RNAi plays multiple biological roles in eukaryotic organisms to regulate gene expression. RNAi also operates as a conserved adaptive molecular immune mechanism against invading viruses. The antiviral RNAi pathway is initiated with the generation of virus-derived short-interfering RNAs (siRNAs that are used for subsequent sequence-specific recognition and degradation of the cognate viral RNA molecules. As an efficient counter-defensive strategy, most plant viruses evolved the ability to encode specific proteins capable of interfering with RNAi, and this process is commonly known as RNA silencing suppression. Virus-encoded suppressors of RNAi (VSRs operate at different steps in the RNAi pathway and display distinct biochemical properties that enable these proteins to efficiently interfere with the host-defense system. Tombusvirus-encoded P19 is an important pathogenicity factor, required for symptom development and elicitation of a hypersensitive response in a host-dependent manner. Protein plays a crucial role of TBSV P19 in protecting viral RNA during systemic infection on Nicotiana benthamiana. The X-ray crystallographic studies conducted by two independent groups revealed the existence of a P19-siRNA complex; a conformation whereby caliper tryptophan residues on two subunits of P19 dimers measure and bind 21-nt siRNA duplexes. These structural studies provided the first details on the possible molecular mechanism of any viral suppressor to block RNAi. The association between P19 and siRNAs was also shown to occur in infected plants These and related studies revealed that in general the ability of P19 to efficiently sequester siRNAs influences symptom severity, however this is not a strict correlation in all hosts.The current working model is that during TBSV infection of plants, P19 appropriates abundantly circulating Tombusvirus-derived siRNAs thereby rendering these unavailable to program RISC, to prevent degradation of

  3. The Interaction of TXNIP and AFq1 Genes Increases the Susceptibility of Schizophrenia.

    Science.gov (United States)

    Su, Yousong; Ding, Wenhua; Xing, Mengjuan; Qi, Dake; Li, Zezhi; Cui, Donghong

    2017-08-01

    Although previous studies showed the reduced risk of cancer in patients with schizophrenia, whether patients with schizophrenia possess genetic factors that also contribute to tumor suppressor is still unknown. In the present study, based on our previous microarray data, we focused on the tumor suppressor genes TXNIP and AF1q, which differentially expressed in patients with schizophrenia. A total of 413 patients and 578 healthy controls were recruited. We found no significant differences in genotype, allele, or haplotype frequencies at the selected five single nucleotide polymorphisms (SNPs) (rs2236566 and rs7211 in TXNIP gene; rs10749659, rs2140709, and rs3738481 in AF1q gene) between patients with schizophrenia and controls. However, we found the association between the interaction of TXNIP and AF1q with schizophrenia by using the MDR method followed by traditional statistical analysis. The best gene-gene interaction model identified was a three-locus model TXNIP (rs2236566, rs7211)-AF1q (rs2140709). After traditional statistical analysis, we found the high-risk genotype combination was rs2236566 (GG)-rs7211(CC)-rs2140709(CC) (OR = 1.35 [1.03-1.76]). The low-risk genotype combination was rs2236566 (GT)-rs7211(CC)-rs2140709(CC) (OR = 0.67 [0.49-0.91]). Our finding suggested statistically significant role of interaction of TXNIP and AF1q polymorphisms (TXNIP-rs2236566, TXNIP-rs7211, and AF1q-rs2769605) in schizophrenia susceptibility.

  4. Hypomethylation and Aberrant Expression of the Glioma Pathogenesis-Related 1 Gene in Wilms Tumors

    Directory of Open Access Journals (Sweden)

    Laxmi Chilukamarri

    2007-11-01

    Full Text Available Wilms tumors (WTs have a complex etiology, displaying genetic and epigenetic changes, including loss of imprinting (LOI and tumor suppressor gene silencing. To identify new regions of epigenetic perturbation in WTs, we screened kidney and tumor DNA using CpG island (CGI tags associated with cancer-specific DNA methylation changes. One such tag corresponded to a paralog of the glioma pathogenesis-related 1/related to testis-specific, vespid, and pathogenesis proteins 1 (GLIPR1/RTVP-1 gene, previously reported to be a tumor-suppressor gene silenced by hypermethylation in prostate cancer. Here we report methylation analysis of the GLIPR1/RTVP-1 gene in WTs and normal fetal and pediatric kidneys. Hypomethylation of the GLIPR1/RTVP-1 5'-region in WTs relative to normal tissue is observed in 21/24 (87.5% of WTs analyzed. Quantitative analysis of GLIPR1/RTVP-1 expression in 24 WTs showed elevated transcript levels in 16/24 WTs (67%, with 12 WTs displaying in excess of 20-fold overexpression relative to fetal kidney (FK control samples. Immunohistochemical analysis of FK and WT corroborates the RNA expression data and reveals high GLIPR1/RTVP-1 in WT blastemal cells together with variable levels in stromal and epithelial components. Hypomethylation is also evident in the WT precursor lesions and nephrogenic rests (NRs, supporting a role for GLIPR1/RTVP-1 deregulation early in Wilms tumorigenesis. Our data show that, in addition to gene dosage changes arising from LOI and hypermethylation-induced gene silencing, gene activation resulting from hypomethylation is also prevalent in WTs.

  5. Suppressor T-cell factor(s) display an altered pattern of Igh (immunoglobulin heavy chain locus) genetic restriction when developed in an Igh-congeneic host

    International Nuclear Information System (INIS)

    HayGlass, K.T.; Naides, S.J.; Benacerraf, B.; Sy, M.S.

    1985-01-01

    Suppressor T cell factor(s) (TsF 1 ) inhibit the in vivo priming of azobenzenearsonate-specific cytotoxic T-cell responses. The activity of TsF 1 is restricted by genes linked to Igh-1 allotypic markers. TsF 1 obtained from B6.Igh-1/sup n/ mice was unable to suppress the immune response in B6.Igh-1/sup b/ mice and vice versa. However, TsF 1 prepared from B6.Igh-1/sup n/ T cells parked in an Igh-congeneic B6.Igh-1/sup b/ environment displays an additional restriction specificity of the host. Thus, TsF 1 prepared from these Igh-chimeric mice suppressed immune responses in both B6.Igh-1/sup n/ (donor) and B6.Igh-1/sup b/ (recipient) mice but not in mice of the unrelated strain BALB/c.Igh-1/sup a/. The results indicate that the establishment of the suppressor T-cell repertoire is dependent not only upon the genetic background of the individual T cell but also upon the influence of Igh-linked determinants present when T-cell clones are selected during the response

  6. Expression of Cucumber mosaic virus suppressor 2b alters FWA methylation and its siRNA accumulation in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Sadia Hamera

    2016-11-01

    Full Text Available The Cucumber mosaic virus (CMV suppressor 2b co-localizes with AGO4 in cytoplasmic and nuclear fractions of Arabidopsis thaliana. Biochemical fractionation of A. thaliana cellular extracts revealed that 2b and AGO4 coexist in multiple size exclusions. 2b transgenic A. thaliana exhibited an enhanced accumulation of 24nt siRNAs from flowering wageningen (FWA and other heterochromatic loci. These plants also exhibited hypo-methylation of an endogenous- as well as transgene-FWA promoter at non-CG sites. In corroboration, both transgenic 2b and CMV infection affected the regulation of transposons which mimics the ago4 phenotype. In conclusion, 2b perturbs plant defense by interfering with AGO4-regulated transcriptional gene silencing.

  7. UV mutagenesis in E. coli with excision repair initiated by uvrABC or denV gene products

    Energy Technology Data Exchange (ETDEWEB)

    Bockrath, R; Hodes, M Z; Mosbaugh, P; Valerie, K; de Riel, J K

    1988-03-01

    Mutation frequency responses produced by ultraviolet light are compared in 4 closely related strains of E.coli B/r having the same tyr(Oc) allele and different excision-repair capabilities. The production of Tyr/sup +/ prototrophic mutants is classified into back-mutations and de novo or converted glutamine tRNA suppressor mutations to indicate different mutation events. Cells transformed with the plasmid pdenV-7 require larger exposures than the parent strains to produce comparable mutation frequency responses, indicating that DenV activity can repair mutatagenic photoproducts. When damage reduction by UvrABC or DenV is compared for each of the specific categories of mutation, the results are consistent with the idea that pyrimidine dimers infrequently or never target back-mutations of this allele, frequently target the de novo suppressor mutations, and extensively or exclusively target the converted suppressor mutations. This analysis is based on the distinction that UvrABC-initiated excision repair recognizes dimer and non-dimer photoproducts but that DenV-initiated repair recognizes only pyrimidine dimers. 44 refs.; 3 figs.; 2 tabs.

  8. Enumerating all maximal frequent subtrees in collections of phylogenetic trees

    Science.gov (United States)

    2014-01-01

    Background A common problem in phylogenetic analysis is to identify frequent patterns in a collection of phylogenetic trees. The goal is, roughly, to find a subset of the species (taxa) on which all or some significant subset of the trees agree. One popular method to do so is through maximum agreement subtrees (MASTs). MASTs are also used, among other things, as a metric for comparing phylogenetic trees, computing congruence indices and to identify horizontal gene transfer events. Results We give algorithms and experimental results for two approaches to identify common patterns in a collection of phylogenetic trees, one based on agreement subtrees, called maximal agreement subtrees, the other on frequent subtrees, called maximal frequent subtrees. These approaches can return subtrees on larger sets of taxa than MASTs, and can reveal new common phylogenetic relationships not present in either MASTs or the majority rule tree (a popular consensus method). Our current implementation is available on the web at https://code.google.com/p/mfst-miner/. Conclusions Our computational results confirm that maximal agreement subtrees and all maximal frequent subtrees can reveal a more complete phylogenetic picture of the common patterns in collections of phylogenetic trees than maximum agreement subtrees; they are also often more resolved than the majority rule tree. Further, our experiments show that enumerating maximal frequent subtrees is considerably more practical than enumerating ordinary (not necessarily maximal) frequent subtrees. PMID:25061474

  9. The LKB1 tumor suppressor differentially affects anchorage independent growth of HPV positive cervical cancer cell lines

    International Nuclear Information System (INIS)

    Mack, Hildegard I.D.; Munger, Karl

    2013-01-01

    Infection with high-risk human papillomaviruses is causally linked to cervical carcinogenesis. However, most lesions caused by high-risk HPV infections do not progress to cancer. Host cell mutations contribute to malignant progression but the molecular nature of such mutations is unknown. Based on a previous study that reported an association between liver kinase B1 (LKB1) tumor suppressor loss and poor outcome in cervical cancer, we sought to determine the molecular basis for this observation. LKB1-negative cervical and lung cancer cells were reconstituted with wild type or kinase defective LKB1 mutants and we examined the importance of LKB1 catalytic activity in known LKB1-regulated processes including inhibition of cell proliferation and elevated resistance to energy stress. Our studies revealed marked differences in the biological activities of two kinase defective LKB1 mutants in the various cell lines. Thus, our results suggest that LKB1 may be a cell-type specific tumor suppressor. - Highlights: • LKB1 is a tumor suppressor that is linked to Peutz-Jeghers syndrome. • Peutz-Jeghers syndrome patients have a high incidence of cervical cancer. • Cervical cancer is caused by HPV infections. • This study investigates LKB1 tumor suppressor activity in cervical cancer

  10. Frequent downregulation of miR-34 family in human ovarian cancers.

    Science.gov (United States)

    Corney, David C; Hwang, Chang-Il; Matoso, Andres; Vogt, Markus; Flesken-Nikitin, Andrea; Godwin, Andrew K; Kamat, Aparna A; Sood, Anil K; Ellenson, Lora H; Hermeking, Heiko; Nikitin, Alexander Yu

    2010-02-15

    The miR-34 family is directly transactivated by tumor suppressor p53, which is frequently mutated in human epithelial ovarian cancer (EOC). We hypothesized that miR-34 expression would be decreased in EOC and that reconstituted miR-34 expression might reduce cell proliferation and invasion of EOC cells. miR-34 expression was determined by quantitative reverse transcription-PCR and in situ hybridization in a panel of 83 human EOC samples. Functional characterization of miR-34 was accomplished by reconstitution of miR-34 expression in EOC cells with synthetic pre-miR molecules followed by determining changes in proliferation, apoptosis, and invasion. miR-34a expression is decreased in 100%, and miR-34b*/c in 72%, of EOC with p53 mutation, whereas miR-34a is also downregulated in 93% of tumors with wild-type p53. Furthermore, expression of miR-34b*/c is significantly reduced in stage IV tumors compared with stage III (P = 0.0171 and P = 0.0029, respectively). Additionally, we observed promoter methylation and copy number variations at mir-34. In situ hybridization showed that miR-34a expression is inversely correlated with MET immunohistochemical staining, consistent with translational inhibition by miR-34a. Finally, miR-34 reconstitution experiments in p53 mutant EOC cells resulted in reduced proliferation, motility, and invasion, the latter of which was dependent on MET expression. Our work suggests that miR-34 family plays an important role in EOC pathogenesis and reduced expression of miR-34b*/c may be particularly important for progression to the most advanced stages. Part of miR-34 effects on motility and invasion may be explained by regulation of MET, which is frequently overexpressed in EOC.

  11. Immortalization of MEF is characterized by the deregulation of specific miRNAs with potential tumor suppressor activity.

    Science.gov (United States)

    Rizzo, Milena; Evangelista, Monica; Simili, Marcella; Mariani, Laura; Pitto, Letizia; Rainaldi, Giuseppe

    2011-07-01

    The life span (Hayflick limit) of primary mouse embryo fibroblasts (MEF) in culture is variable but it is still unclear if the escape of the Hayflick limit is also variable. To address this point MEF were expanded every fifteen days (6T15) instead of every three days (6T3) until they became immortal. With this protocol MEF lifespan was extended and immortalization accordingly delayed. By testing a panel of genes (p19ARF, p16, p21) and miRNAs (miR-20a, miR-21, miR-28, miR-290) related to primary MEF senescence, a switch of p21 from up to down regulation, the down regulation of specific miRNAs as well as a massive shift from diploidy to hyperdiploidy were observed in coincidence with the resumption of cell proliferation. Collectively, these data indicate that the inactivation of genes and miRNAs, important in controlling cell proliferation, might be determinant for the escape from the Hayflick limit. In support of this hypothesis was the finding that some of the down regulated miRNAs transfected in immortalized MEF inhibited cell proliferation thus displaying a tumor suppressor-like activity.

  12. Insulin dependent diabetes mellitus (IDDM) and autoimmune thyroiditis in a boy with a ring chromosome 18: additional evidence of autoimmunity or IDDM gene(s) on chromosome 18.

    Science.gov (United States)

    Dacou-Voutetakis, C; Sertedaki, A; Maniatis-Christidis, M; Sarri, C; Karadima, G; Petersen, M B; Xaidara, A; Kanariou, M; Nicolaidou, P

    1999-02-01

    A 4 year 3 month old boy with insulin dependent diabetes mellitus (IDDM), autoimmune thyroiditis, slight mental retardation, facial dysmorphism, and a de novo ring chromosome 18 (deletion 18q22.3-18qter) is described. This unique association of defects could represent a chance association. Alternatively, the clinical features could be the result of the chromosomal aberration. If so, one could speculate that a gene or genes on chromosome 18 might act as a suppressor or activator of the autoimmune process by itself or in concert with other IDDM loci.

  13. SLC5A8 gene, a transporter of butyrate: a gut flora metabolite, is frequently methylated in African American colon adenomas.

    Directory of Open Access Journals (Sweden)

    Hassan Brim

    Full Text Available Colon cancer is one of the leading causes of cancer related deaths. Its impact on African Americans (AAs is higher than in the general population both in the incidence and mortality from the disease. Colon cancer aggressiveness in AAs as well as non-frequent check-ups and follow up in this population have been proposed as ways to explain the observed discrepancies. These facts made the detection of early carcinogenesis markers in this population a priority.Here, we analyzed 50 colon adenomas from AA patients for both microsatellite instability (MSI and the methylation status of SLC5A8 gene. This gene's product is involved in the transport of butyrate that has anti-proliferative properties through its effects on histone acetylation and gene expression. A proteomic analysis to check the expressed histones in adenoma and normal tissues was also performed.The analyzed samples displayed 82% (n = 41 methylation level of SLC5A8 gene in adenomas. The MSI-H (high adenoma were about 18% (n = 9 while the rest were mostly MSS (microsatellite stable with few MSI-L (Low. No association was found between SLC5A8 methylation and the MSI status. Also, there was no association between SLC5A8 methylation and the sex and age of the patients. However, there were more right sided adenomas with SLC5A8 methylation than the left sided ones. The proteomic analysis revealed distinct histone expression profiles between normal and adenoma tissues.SLC5A8 is highly methylated in AA colon adenomas which points to its potential use as a marker for early detection. The MSI rate is similar to that found in colon cancer tumors in AAs. These findings suggest that both processes stem from the same epigenetic and genetic events occurring at an early stage in colon carcinogenesis in AAs.

  14. The PR-Set7 binding domain of Riz1 is required for the H4K20me1-H3K9me1 trans-tail ‘histone code’ and Riz1 tumor suppressor function

    Science.gov (United States)

    Congdon, Lauren M.; Sims, Jennifer K.; Tuzon, Creighton T.; Rice, Judd C.

    2014-01-01

    PR-Set7/Set8/KMT5a is the sole histone H4 lysine 20 monomethyltransferase (H4K20me1) in metazoans and is essential for proper cell division and genomic stability. We unexpectedly discovered that normal cellular levels of monomethylated histone H3 lysine 9 (H3K9me1) were also dependent on PR-Set7, but independent of its catalytic activity. This observation suggested that PR-Set7 interacts with an H3K9 monomethyltransferase to establish the previously reported H4K20me1-H3K9me1 trans-tail ‘histone code’. Here we show that PR-Set7 specifically and directly binds the C-terminus of the Riz1/PRDM2/KMT8 tumor suppressor and demonstrate that the N-terminal PR/SET domain of Riz1 preferentially monomethylates H3K9. The PR-Set7 binding domain was required for Riz1 nuclear localization and maintenance of the H4K20me1-H3K9me1 trans-tail ‘histone code’. Although Riz1 can function as a repressor, Riz1/H3K9me1 was dispensable for the repression of genes regulated by PR-Set7/H4K20me1. Frameshift mutations resulting in a truncated Riz1 incapable of binding PR-Set7 occur frequently in various aggressive cancers. In these cancer cells, expression of wild-type Riz1 restored tumor suppression by decreasing proliferation and increasing apoptosis. These phenotypes were not observed in cells expressing either the Riz1 PR/SET domain or PR-Set7 binding domain indicating that Riz1 methyltransferase activity and PR-Set7 binding domain are both essential for Riz1 tumor suppressor function. PMID:24423864

  15. Monocytic and granulocytic myeloid derived suppressor cells differentially regulate spatiotemporal tumour plasticity during metastatic cascade.

    Science.gov (United States)

    Ouzounova, Maria; Lee, Eunmi; Piranlioglu, Raziye; El Andaloussi, Abdeljabar; Kolhe, Ravindra; Demirci, Mehmet F; Marasco, Daniela; Asm, Iskander; Chadli, Ahmed; Hassan, Khaled A; Thangaraju, Muthusamy; Zhou, Gang; Arbab, Ali S; Cowell, John K; Korkaya, Hasan

    2017-04-06

    It is widely accepted that dynamic and reversible tumour cell plasticity is required for metastasis, however, in vivo steps and molecular mechanisms are poorly elucidated. We demonstrate here that monocytic (mMDSC) and granulocytic (gMDSC) subsets of myeloid-derived suppressor cells infiltrate in the primary tumour and distant organs with different time kinetics and regulate spatiotemporal tumour plasticity. Using co-culture experiments and mouse transcriptome analyses in syngeneic mouse models, we provide evidence that tumour-infiltrated mMDSCs facilitate tumour cell dissemination from the primary site by inducing EMT/CSC phenotype. In contrast, pulmonary gMDSC infiltrates support the metastatic growth by reverting EMT/CSC phenotype and promoting tumour cell proliferation. Furthermore, lung-derived gMDSCs isolated from tumour-bearing animals enhance metastatic growth of already disseminated tumour cells. MDSC-induced 'metastatic gene signature' derived from murine syngeneic model predicts poor patient survival in the majority of human solid tumours. Thus spatiotemporal MDSC infiltration may have clinical implications in tumour progression.

  16. Specificity and autoregulation of Notch binding by tandem WW domains in suppressor of Deltex.

    Science.gov (United States)

    Jennings, Martin D; Blankley, Richard T; Baron, Martin; Golovanov, Alexander P; Avis, Johanna M

    2007-09-28

    WW domains target proline-tyrosine (PY) motifs and frequently function as tandem pairs. When studied in isolation, single WW domains are notably promiscuous and regulatory mechanisms are undoubtedly required to ensure selective interactions. Here, we show that the fourth WW domain (WW4) of Suppressor of Deltex, a modular Nedd4-like protein that down-regulates the Notch receptor, is the primary mediator of a direct interaction with a Notch-PY motif. A natural Trp to Phe substitution in WW4 reduces its affinity for general PY sequences and enhances selective interaction with the Notch-PY motif via compensatory specificity-determining interactions with PY-flanking residues. When WW4 is paired with WW3, domain-domain association, impeding proper folding, competes with Notch-PY binding to WW4. This novel mode of autoinhibition is relieved by binding of another ligand to WW3. Such cooperativity may facilitate the transient regulatory interactions observed in vivo between Su(dx) and Notch in the endocytic pathway. The highly conserved tandem arrangement of WW domains in Nedd4 proteins, and similar arrangements in more diverse proteins, suggests domain-domain communication may be integral to regulation of their associated cellular activities.

  17. Regulatory T cells as suppressors of anti-tumor immunity: Role of metabolism.

    Science.gov (United States)

    De Rosa, Veronica; Di Rella, Francesca; Di Giacomo, Antonio; Matarese, Giuseppe

    2017-06-01

    Novel concepts in immunometabolism support the hypothesis that glucose consumption is also used to modulate anti-tumor immune responses, favoring growth and expansion of specific cellular subsets defined in the past as suppressor T cells and currently reborn as regulatory T (Treg) cells. During the 1920s, Otto Warburg and colleagues observed that tumors consumed high amounts of glucose compared to normal tissues, even in the presence of oxygen and completely functioning mitochondria. However, the role of the Warburg Effect is still not completely understood, particularly in the context of an ongoing anti-tumor immune response. Current experimental evidence suggests that tumor-derived metabolic restrictions can drive T cell hyporesponsiveness and immune tolerance. For example, several glycolytic enzymes, deregulated in cancer, contribute to tumor progression independently from their canonical metabolic activity. Indeed, they can control apoptosis, gene expression and activation of specific intracellular pathways, thus suggesting a direct link between metabolic switches and pro-tumorigenic transcriptional programs. Focus of this review is to define the specific metabolic pathways controlling Treg cell immunobiology in the context of anti-tumor immunity and tumor progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Frequent genes in rare diseases: panel-based next generation sequencing to disclose causal mutations in hereditary neuropathies.

    Science.gov (United States)

    Dohrn, Maike F; Glöckle, Nicola; Mulahasanovic, Lejla; Heller, Corina; Mohr, Julia; Bauer, Christine; Riesch, Erik; Becker, Andrea; Battke, Florian; Hörtnagel, Konstanze; Hornemann, Thorsten; Suriyanarayanan, Saranya; Blankenburg, Markus; Schulz, Jörg B; Claeys, Kristl G; Gess, Burkhard; Katona, Istvan; Ferbert, Andreas; Vittore, Debora; Grimm, Alexander; Wolking, Stefan; Schöls, Ludger; Lerche, Holger; Korenke, G Christoph; Fischer, Dirk; Schrank, Bertold; Kotzaeridou, Urania; Kurlemann, Gerhard; Dräger, Bianca; Schirmacher, Anja; Young, Peter; Schlotter-Weigel, Beate; Biskup, Saskia

    2017-12-01

    Hereditary neuropathies comprise a wide variety of chronic diseases associated to more than 80 genes identified to date. We herein examined 612 index patients with either a Charcot-Marie-Tooth phenotype, hereditary sensory neuropathy, familial amyloid neuropathy, or small fiber neuropathy using a customized multigene panel based on the next generation sequencing technique. In 121 cases (19.8%), we identified at least one putative pathogenic mutation. Of these, 54.4% showed an autosomal dominant, 33.9% an autosomal recessive, and 11.6% an X-linked inheritance. The most frequently affected genes were PMP22 (16.4%), GJB1 (10.7%), MPZ, and SH3TC2 (both 9.9%), and MFN2 (8.3%). We further detected likely or known pathogenic variants in HINT1, HSPB1, NEFL, PRX, IGHMBP2, NDRG1, TTR, EGR2, FIG4, GDAP1, LMNA, LRSAM1, POLG, TRPV4, AARS, BIC2, DHTKD1, FGD4, HK1, INF2, KIF5A, PDK3, REEP1, SBF1, SBF2, SCN9A, and SPTLC2 with a declining frequency. Thirty-four novel variants were considered likely pathogenic not having previously been described in association with any disorder in the literature. In one patient, two homozygous mutations in HK1 were detected in the multigene panel, but not by whole exome sequencing. A novel missense mutation in KIF5A was considered pathogenic because of the highly compatible phenotype. In one patient, the plasma sphingolipid profile could functionally prove the pathogenicity of a mutation in SPTLC2. One pathogenic mutation in MPZ was identified after being previously missed by Sanger sequencing. We conclude that panel based next generation sequencing is a useful, time- and cost-effective approach to assist clinicians in identifying the correct diagnosis and enable causative treatment considerations. © 2017 International Society for Neurochemistry.

  19. Gelsolin functions as a metastasis suppressor in B16-BL6 mouse melanoma cells and requirement of the carboxyl-terminus for its effect.

    Science.gov (United States)

    Fujita, H; Okada, F; Hamada , J; Hosokawa, M; Moriuchi, T; Koya, R C; Kuzumaki, N

    2001-09-01

    Gelsolin, an actin-binding protein, is implicated as a critical regulator in cell motility. In addition, we have reported that cellular levels of gelsolin are decreased in various tumor cells, and overexpression of gelsolin by gene transfer suppresses tumorigenicity. We sought to assess the effects of gelsolin overexpression on metastasis and to determine the importance of a carboxyl-terminus that confers Ca(2+) dependency on gelsolin for effects of its overexpression. Expression vectors with cDNA encoding either full-length wild-type or His321 mutant form, isolated from a flat revertant of Ras-transformed cells and a carboxyl-terminal truncate, C-del of gelsolin, were transfected into a highly metastatic murine melanoma cell line, B16-BL6. Expression of introduced cDNA in transfectants was confirmed using Western blotting, 2-dimensional gel electrophoresis and reverse transcription-polymerase chain reaction (RT-PCR). We characterized phenotypes of transfectants, such as growth rate, colony formation in soft agar, cell motility and metastasis formation in vivo. Transfectants expressing the wild-type, His321 mutant and C-del gelsolin exhibited reduced growth ability in soft agar. Although expression of integrin beta1 or alpha4 on the cell surface of transfectants was not changed, wild-type and His321 mutant gelsolin, except for C-del gelsolin, exhibited retardation of cell spreading, reduced chemotatic migration to fibronectin and suppressed lung colonization in spontaneous metastasis assay. Gelsolin may function as a metastasis suppressor as well as a tumor suppressor gene. The carboxyl-terminus of gelsolin is important for retardation of cell spreading, reduced chemotasis and metastasis suppression. Copyright 2001 Wiley-Liss, Inc.

  20. RUNX1 promotes cell growth in human T-cell acute lymphoblastic leukemia by transcriptional regulation of key target genes.

    Science.gov (United States)

    Jenkins, Catherine E; Gusscott, Samuel; Wong, Rachel J; Shevchuk, Olena O; Rana, Gurneet; Giambra, Vincenzo; Tyshchenko, Kateryna; Islam, Rashedul; Hirst, Martin; Weng, Andrew P

    2018-05-04

    RUNX1 is frequently mutated in T-cell acute lymphoblastic leukemia (T-ALL). The spectrum of RUNX1 mutations has led to the notion that it acts as a tumor suppressor in this context; however, other studies have placed RUNX1 along with transcription factors TAL1 and NOTCH1 as core drivers of an oncogenic transcriptional program. To reconcile these divergent roles, we knocked down RUNX1 in human T-ALL cell lines and deleted Runx1 or Cbfb in primary mouse T-cell leukemias. RUNX1 depletion consistently resulted in reduced cell proliferation and increased apoptosis. RUNX1 upregulated variable sets of target genes in each cell line, but consistently included a core set of oncogenic effectors including IGF1R and NRAS. Our results support the conclusion that RUNX1 has a net positive effect on cell growth in the context of established T-ALL. Copyright © 2018. Published by Elsevier Inc.

  1. HSMNR belongs to the most frequent types of hereditary neuropathy in the Czech Republic and is twice more frequent than HMSNL.

    Science.gov (United States)

    Šafka Brožková, D; Haberlová, J; Mazanec, R; Laštůvková, J; Seeman, P

    2016-08-01

    Hereditary motor and sensory neuropathy type Russe (HMSNR), also called CMT4G, is an autosomal recessive inherited peripheral neuropathy (IPN) caused by a founder mutation in the HK1 gene. HMSNR affects only patients with Roma origin, similar to the better known HMSN type Lom clarified earlier. By testing IPN patients with Roma origin, we realized that HMSNR affects surprisingly many patients in the Czech Republic. HMSNR is one of the most frequent types of IPN in this country and appears to be twice more frequent than HMSNL. Pronounced lower limb atrophies and severe deformities often lead to walking inability in even young patients, but hands are usually only mildly affected even after many years of disease duration. The group of 20 patients with HMSNR presented here is the first report about the prevalence of HMSNR from central Europe. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

    NARCIS (Netherlands)

    Chiu, Hua Sheng; Somvanshi, Sonal; Patel, Ektaben; Chen, Ting Wen; Singh, Vivek P.; Zorman, Barry; Patil, Sagar L.; Pan, Yinghong; Chatterjee, Sujash S.; Caesar-Johnson, Samantha J.; Demchok, John A.; Felau, Ina; Kasapi, Melpomeni; Ferguson, Martin L.; Hutter, Carolyn M.; Sofia, Heidi J.; Tarnuzzer, Roy; Wang, Zhining; Yang, Liming; Zenklusen, Jean C.; Zhang, Jiashan (Julia); Chudamani, Sudha; Liu, Jia; Lolla, Laxmi; Naresh, Rashi; Pihl, Todd; Sun, Qiang; Wan, Yunhu; Wu, Ye; Cho, Juok; DeFreitas, Timothy; Frazer, Scott; Gehlenborg, Nils; Getz, Gad; Heiman, David I.; Kim, Jaegil; Lawrence, Michael S.; Lin, Pei; Meier, Sam; Noble, Michael S.; Saksena, Gordon; Voet, Doug; Zhang, Hailei; Bernard, Brady; Chambwe, Nyasha; Dhankani, Varsha; Knijnenburg, Theo; Kramer, Roger; Leinonen, Kalle; Liu, Yuexin; Miller, Michael; Reynolds, Sheila; Shmulevich, Ilya; Thorsson, Vesteinn; Zhang, Wei; Akbani, Rehan; Broom, Bradley M.; Hegde, Apurva M.; Ju, Zhenlin; Kanchi, Rupa S.; Korkut, Anil; Li, Jun; Liang, Han; Ling, Shiyun; Liu, Wenbin; Lu, Yiling; Mills, Gordon B.; Ng, Kwok Shing; Rao, Arvind; Ryan, Michael; Wang, Jing; Weinstein, John N.; Zhang, Jiexin; Abeshouse, Adam; Armenia, Joshua; Chakravarty, Debyani; Chatila, Walid K.; de Bruijn, Ino; Gao, Jianjiong; Gross, Benjamin E.; Heins, Zachary J.; Kundra, Ritika; La, Konnor; Ladanyi, Marc; Luna, Augustin; Nissan, Moriah G.; Ochoa, Angelica; Phillips, Sarah M.; Reznik, Ed; Sanchez-Vega, Francisco; Sander, Chris; Schultz, Nikolaus; Sheridan, Robert; Sumer, S. Onur; Sun, Yichao; Taylor, Barry S.; Wang, Jioajiao; Zhang, Hongxin; Anur, Pavana; Peto, Myron; Spellman, Paul; Benz, Christopher; Stuart, Joshua M.; Wong, Christopher K.; Yau, Christina; Hayes, D. Neil; Parker, Joel S.; Wilkerson, Matthew D.; Ally, Adrian; Balasundaram, Miruna; Bowlby, Reanne; Brooks, Denise; Carlsen, Rebecca; Chuah, Eric; Dhalla, Noreen; Holt, Robert; Jones, Steven J.M.; Kasaian, Katayoon; Lee, Darlene; Ma, Yussanne; Marra, Marco A.; Mayo, Michael; Moore, Richard A.; Mungall, Andrew J.; Mungall, Karen; Robertson, A. Gordon; Sadeghi, Sara; Schein, Jacqueline E.; Sipahimalani, Payal; Tam, Angela; Thiessen, Nina; Tse, Kane; Wong, Tina; Berger, Ashton C.; Beroukhim, Rameen; Cherniack, Andrew D.; Cibulskis, Carrie; Gabriel, Stacey B.; Gao, Galen F.; Ha, Gavin; Meyerson, Matthew; Schumacher, Steven E.; Shih, Juliann; Kucherlapati, Melanie H.; Kucherlapati, Raju S.; Baylin, Stephen; Cope, Leslie; Danilova, Ludmila; Bootwalla, Moiz S.; Lai, Phillip H.; Maglinte, Dennis T.; Van Den Berg, David J.; Weisenberger, Daniel J.; Auman, J. Todd; Balu, Saianand; Bodenheimer, Tom; Fan, Cheng; Hoadley, Katherine A.; Hoyle, Alan P.; Jefferys, Stuart R.; Jones, Corbin D.; Meng, Shaowu; Mieczkowski, Piotr A.; Mose, Lisle E.; Perou, Amy H.; Perou, Charles M.; Roach, Jeffrey; Shi, Yan; Simons, Janae V.; Skelly, Tara; Soloway, Matthew G.; Tan, Donghui; Veluvolu, Umadevi; Fan, Huihui; Hinoue, Toshinori; Laird, Peter W.; Shen, Hui; Zhou, Wanding; Bellair, Michelle; Chang, Kyle; Covington, Kyle; Creighton, Chad J.; Dinh, Huyen; Doddapaneni, Harsha Vardhan; Donehower, Lawrence A.; Drummond, Jennifer; Gibbs, Richard A.; Glenn, Robert; Hale, Walker; Han, Yi; Hu, Jianhong; Korchina, Viktoriya; Lee, Sandra; Lewis, Lora; Li, Wei; Liu, Xiuping; Morgan, Margaret; Morton, Donna; Muzny, Donna; Santibanez, Jireh; Sheth, Margi; Shinbrot, Eve; Wang, Linghua; Wang, Min; Wheeler, David A.; Xi, Liu; Zhao, Fengmei; Hess, Julian; Appelbaum, Elizabeth L.; Bailey, Matthew; Cordes, Matthew G.; Ding, Li; Fronick, Catrina C.; Fulton, Lucinda A.; Fulton, Robert S.; Kandoth, Cyriac; Mardis, Elaine R.; McLellan, Michael D.; Miller, Christopher A.; Schmidt, Heather K.; Wilson, Richard K.; Crain, Daniel; Curley, Erin; Gardner, Johanna; Lau, Kevin; Mallery, David; Morris, Scott; Paulauskis, Joseph; Penny, Robert; Shelton, Candace; Shelton, Troy; Sherman, Mark; Thompson, Eric; Yena, Peggy; Bowen, Jay; Gastier-Foster, Julie M.; Gerken, Mark; Leraas, Kristen M.; Lichtenberg, Tara M.; Ramirez, Nilsa C.; Wise, Lisa; Zmuda, Erik; Corcoran, Niall; Costello, Tony; Hovens, Christopher; Carvalho, Andre L.; de Carvalho, Ana C.; Fregnani, José H.; Longatto-Filho, Adhemar; Reis, Rui M.; Scapulatempo-Neto, Cristovam; Silveira, Henrique C.S.; Vidal, Daniel O.; Burnette, Andrew; Eschbacher, Jennifer; Hermes, Beth; Noss, Ardene; Singh, Rosy; Anderson, Matthew L.; Castro, Patricia D.; Ittmann, Michael; Huntsman, David; Kohl, Bernard; Le, Xuan; Thorp, Richard; Andry, Chris; Duffy, Elizabeth R.; Lyadov, Vladimir; Paklina, Oxana; Setdikova, Galiya; Shabunin, Alexey; Tavobilov, Mikhail; McPherson, Christopher; Warnick, Ronald; Berkowitz, Ross; Cramer, Daniel; Feltmate, Colleen; Horowitz, Neil; Kibel, Adam; Muto, Michael; Raut, Chandrajit P.; Malykh, Andrei; Barnholtz-Sloan, Jill S.; Barrett, Wendi; Devine, Karen; Fulop, Jordonna; Ostrom, Quinn T.; Shimmel, Kristen; Wolinsky, Yingli; Sloan, Andrew E.; De Rose, Agostino; Giuliante, Felice; Goodman, Marc; Karlan, Beth Y.; Hagedorn, Curt H.; Eckman, John; Harr, Jodi; Myers, Jerome; Tucker, Kelinda; Zach, Leigh Anne; Deyarmin, Brenda; Hu, Hai; Kvecher, Leonid; Larson, Caroline; Mural, Richard J.; Somiari, Stella; Vicha, Ales; Zelinka, Tomas; Bennett, Joseph; Iacocca, Mary; Rabeno, Brenda; Swanson, Patricia; Latour, Mathieu; Lacombe, Louis; Têtu, Bernard; Bergeron, Alain; McGraw, Mary; Staugaitis, Susan M.; Chabot, John; Hibshoosh, Hanina; Sepulveda, Antonia; Su, Tao; Wang, Timothy; Potapova, Olga; Voronina, Olga; Desjardins, Laurence; Mariani, Odette; Roman-Roman, Sergio; Sastre, Xavier; Stern, Marc Henri; Cheng, Feixiong; Signoretti, Sabina; Berchuck, Andrew; Bigner, Darell; Lipp, Eric; Marks, Jeffrey; McCall, Shannon; McLendon, Roger; Secord, Angeles; Sharp, Alexis; Behera, Madhusmita; Brat, Daniel J.; Chen, Amy; Delman, Keith; Force, Seth; Khuri, Fadlo; Magliocca, Kelly; Maithel, Shishir; Olson, Jeffrey J.; Owonikoko, Taofeek; Pickens, Alan; Ramalingam, Suresh; Shin, Dong M.; Sica, Gabriel; Van Meir, Erwin G.; Zhang, Hongzheng; Eijckenboom, Wil; Gillis, Ad; Korpershoek, Esther; Looijenga, Leendert; Oosterhuis, Wolter; Stoop, Hans; van Kessel, Kim E.; Zwarthoff, Ellen C.; Calatozzolo, Chiara; Cuppini, Lucia; Cuzzubbo, Stefania; DiMeco, Francesco; Finocchiaro, Gaetano; Mattei, Luca; Perin, Alessandro; Pollo, Bianca; Chen, Chu; Houck, John; Lohavanichbutr, Pawadee; Hartmann, Arndt; Stoehr, Christine; Stoehr, Robert; Taubert, Helge; Wach, Sven; Wullich, Bernd; Kycler, Witold; Murawa, Dawid; Wiznerowicz, Maciej; Chung, Ki; Edenfield, W. Jeffrey; Martin, Julie; Baudin, Eric; Bubley, Glenn; Bueno, Raphael; De Rienzo, Assunta; Richards, William G.; Kalkanis, Steven; Mikkelsen, Tom; Noushmehr, Houtan; Scarpace, Lisa; Girard, Nicolas; Aymerich, Marta; Campo, Elias; Giné, Eva; Guillermo, Armando López; Van Bang, Nguyen; Hanh, Phan Thi; Phu, Bui Duc; Tang, Yufang; Colman, Howard; Evason, Kimberley; Dottino, Peter R.; Martignetti, John A.; Gabra, Hani; Juhl, Hartmut; Akeredolu, Teniola; Stepa, Serghei; Hoon, Dave; Ahn, Keunsoo; Kang, Koo Jeong; Beuschlein, Felix; Breggia, Anne; Birrer, Michael; Bell, Debra; Borad, Mitesh; Bryce, Alan H.; Castle, Erik; Chandan, Vishal; Cheville, John; Copland, John A.; Farnell, Michael; Flotte, Thomas; Giama, Nasra; Ho, Thai; Kendrick, Michael; Kocher, Jean Pierre; Kopp, Karla; Moser, Catherine; Nagorney, David; O'Brien, Daniel; O'Neill, Brian Patrick; Patel, Tushar; Petersen, Gloria; Que, Florencia; Rivera, Michael; Roberts, Lewis; Smallridge, Robert; Smyrk, Thomas; Stanton, Melissa; Thompson, R. Houston; Torbenson, Michael; Yang, Ju Dong; Zhang, Lizhi; Brimo, Fadi; Ajani, Jaffer A.; Gonzalez, Ana Maria Angulo; Behrens, Carmen; Bondaruk, Jolanta; Broaddus, Russell; Czerniak, Bogdan; Esmaeli, Bita; Fujimoto, Junya; Gershenwald, Jeffrey; Guo, Charles; Lazar, Alexander J.; Logothetis, Christopher; Meric-Bernstam, Funda; Moran, Cesar; Ramondetta, Lois; Rice, David; Sood, Anil; Tamboli, Pheroze; Thompson, Timothy; Troncoso, Patricia; Tsao, Anne; Wistuba, Ignacio; Carter, Candace; Haydu, Lauren; Hersey, Peter; Jakrot, Valerie; Kakavand, Hojabr; Kefford, Richard; Lee, Kenneth; Long, Georgina; Mann, Graham; Quinn, Michael; Saw, Robyn; Scolyer, Richard; Shannon, Kerwin; Spillane, Andrew; Stretch, Jonathan; Synott, Maria; Thompson, John; Wilmott, James; Al-Ahmadie, Hikmat; Chan, Timothy A.; Ghossein, Ronald; Gopalan, Anuradha; Levine, Douglas A.; Reuter, Victor; Singer, Samuel; Singh, Bhuvanesh; Tien, Nguyen Viet; Broudy, Thomas; Mirsaidi, Cyrus; Nair, Praveen; Drwiega, Paul; Miller, Judy; Smith, Jennifer; Zaren, Howard; Park, Joong Won; Hung, Nguyen Phi; Kebebew, Electron; Linehan, W. Marston; Metwalli, Adam R.; Pacak, Karel; Pinto, Peter A.; Schiffman, Mark; Schmidt, Laura S.; Vocke, Cathy D.; Wentzensen, Nicolas; Worrell, Robert; Yang, Hannah; Moncrieff, Marc; Goparaju, Chandra; Melamed, Jonathan; Pass, Harvey; Botnariuc, Natalia; Caraman, Irina; Cernat, Mircea; Chemencedji, Inga; Clipca, Adrian; Doruc, Serghei; Gorincioi, Ghenadie; Mura, Sergiu; Pirtac, Maria; Stancul, Irina; Tcaciuc, Diana; Albert, Monique; Alexopoulou, Iakovina; Arnaout, Angel; Bartlett, John; Engel, Jay; Gilbert, Sebastien; Parfitt, Jeremy; Sekhon, Harman; Thomas, George; Rassl, Doris M.; Rintoul, Robert C.; Bifulco, Carlo; Tamakawa, Raina; Urba, Walter; Hayward, Nicholas; Timmers, Henri; Antenucci, Anna; Facciolo, Francesco; Grazi, Gianluca; Marino, Mirella; Merola, Roberta; de Krijger, Ronald; Gimenez-Roqueplo, Anne Paule; Piché, Alain; Chevalier, Simone; McKercher, Ginette; Birsoy, Kivanc; Barnett, Gene; Brewer, Cathy; Farver, Carol; Naska, Theresa; Pennell, Nathan A.; Raymond, Daniel; Schilero, Cathy; Smolenski, Kathy; Williams, Felicia; Morrison, Carl; Borgia, Jeffrey A.; Liptay, Michael J.; Pool, Mark; Seder, Christopher W.; Junker, Kerstin; Omberg, Larsson; Dinkin, Mikhail; Manikhas, George; Alvaro, Domenico; Bragazzi, Maria Consiglia; Cardinale, Vincenzo; Carpino, Guido; Gaudio, Eugenio; Chesla, David; Cottingham, Sandra; Dubina, Michael; Moiseenko, Fedor; Dhanasekaran, Renumathy; Becker, Karl Friedrich; Janssen, Klaus Peter; Slotta-Huspenina, Julia; Abdel-Rahman, Mohamed H.; Aziz, Dina; Bell, Sue; Cebulla, Colleen M.; Davis, Amy; Duell, Rebecca; Elder, J. Bradley; Hilty, Joe; Kumar, Bahavna; Lang, James; Lehman, Norman L.; Mandt, Randy; Nguyen, Phuong; Pilarski, Robert; Rai, Karan; Schoenfield, Lynn; Senecal, Kelly; Wakely, Paul; Hansen, Paul; Lechan, Ronald; Powers, James; Tischler, Arthur; Grizzle, William E.; Sexton, Katherine C.; Kastl, Alison; Henderson, Joel; Porten, Sima; Waldmann, Jens; Fassnacht, Martin; Asa, Sylvia L.; Schadendorf, Dirk; Couce, Marta; Graefen, Markus; Huland, Hartwig; Sauter, Guido; Schlomm, Thorsten; Simon, Ronald; Tennstedt, Pierre; Olabode, Oluwole; Nelson, Mark; Bathe, Oliver; Carroll, Peter R.; Chan, June M.; Disaia, Philip; Glenn, Pat; Kelley, Robin K.; Landen, Charles N.; Phillips, Joanna; Prados, Michael; Simko, Jeffry; Smith-McCune, Karen; VandenBerg, Scott; Roggin, Kevin; Fehrenbach, Ashley; Kendler, Ady; Sifri, Suzanne; Steele, Ruth; Jimeno, Antonio; Carey, Francis; Forgie, Ian; Mannelli, Massimo; Carney, Michael; Hernandez, Brenda; Campos, Benito; Herold-Mende, Christel; Jungk, Christin; Unterberg, Andreas; von Deimling, Andreas; Bossler, Aaron; Galbraith, Joseph; Jacobus, Laura; Knudson, Michael; Knutson, Tina; Ma, Deqin; Milhem, Mohammed; Sigmund, Rita; Godwin, Andrew K.; Madan, Rashna; Rosenthal, Howard G.; Adebamowo, Clement; Adebamowo, Sally N.; Boussioutas, Alex; Beer, David; Giordano, Thomas; Mes-Masson, Anne Marie; Saad, Fred; Bocklage, Therese; Landrum, Lisa; Mannel, Robert; Moore, Kathleen; Moxley, Katherine; Postier, Russel; Walker, Joan; Zuna, Rosemary; Feldman, Michael; Valdivieso, Federico; Dhir, Rajiv; Luketich, James; Pinero, Edna M.Mora; Quintero-Aguilo, Mario; Carlotti, Carlos Gilberto; Dos Santos, Jose Sebastião; Kemp, Rafael; Sankarankuty, Ajith; Tirapelli, Daniela; Catto, James; Agnew, Kathy; Swisher, Elizabeth; Creaney, Jenette; Robinson, Bruce; Shelley, Carl Simon; Godwin, Eryn M.; Kendall, Sara; Shipman, Cassaundra; Bradford, Carol; Carey, Thomas; Haddad, Andrea; Moyer, Jeffey; Peterson, Lisa; Prince, Mark; Rozek, Laura; Wolf, Gregory; Bowman, Rayleen; Fong, Kwun M.; Yang, Ian; Korst, Robert; Rathmell, W. Kimryn; Fantacone-Campbell, J. Leigh; Hooke, Jeffrey A.; Kovatich, Albert J.; Shriver, Craig D.; DiPersio, John; Drake, Bettina; Govindan, Ramaswamy; Heath, Sharon; Ley, Timothy; Van Tine, Brian; Westervelt, Peter; Rubin, Mark A.; Lee, Jung Il; Aredes, Natália D.; Mariamidze, Armaz; Sood, Anil K.; Gunaratne, Preethi H.; Sumazin, Pavel

    2018-01-01

    Long noncoding RNAs (lncRNAs) are commonly dysregulated in tumors, but only a handful are known to play pathophysiological roles in cancer. We inferred lncRNAs that dysregulate cancer pathways, oncogenes, and tumor suppressors (cancer genes) by modeling their effects on the activity of transcription

  3. Alteration of BRCA1 expression affects alcohol-induced transcription of RNA Pol III-dependent genes.

    Science.gov (United States)

    Zhong, Qian; Shi, Ganggang; Zhang, Yanmei; Lu, Lei; Levy, Daniel; Zhong, Shuping

    2015-02-01

    Emerging evidence has indicated that alcohol consumption is an established risk factor for breast cancer. Deregulation of RNA polymerase III (Pol III) transcription enhances cellular Pol III gene production, leading to an increase in translational capacity to promote cell transformation and tumor formation. We have reported that alcohol intake increases Pol III gene transcription to promote cell transformation and tumor formation in vitro and in vivo. Studies revealed that tumor suppressors, pRb, p53, PTEN and Maf1 repress the transcription of Pol III genes. BRCA1 is a tumor suppressor and its mutation is tightly related to breast cancer development. However, it is not clear whether BRCA1 expression affects alcohol-induced transcription of Pol III genes. At the present studies, we report that restoring BRCA1 in HCC 1937 cells, which is a BRCA1 deficient cell line, represses Pol III gene transcription. Expressing mutant or truncated BRCA1 in these cells does not affect the ability of repression on Pol III genes. Our analysis has demonstrated that alcohol induces Pol III gene transcription. More importantly, overexpression of BRCA1 in estrogen receptor positive (ER+) breast cancer cells (MCF-7) decreases the induction of tRNA(Leu) and 5S rRNA genes by alcohol, whereas reduction of BRCA1 by its siRNA slightly increases the transcription of the class of genes. This suggests that BRCA1 is associated with alcohol-induced deregulation of Pol III genes. These studies for the first time demonstrate the role of BRCA1 in induction of Pol III genes by alcohol and uncover a novel mechanism of alcohol-associated breast cancer. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Identification and characterization of an inner ear-expressed human melanoma inhibitory activity (MIA)-like gene (MIAL) with a frequent polymorphism that abolishes translation

    DEFF Research Database (Denmark)

    Rendtorff, Nanna Dahl; Frödin, M; Attié-Bitach, T

    2001-01-01

    hybridization or reverse transcription-polymerase chain reaction. The cDNA of the mouse homologue was also cloned and mapped about 80 cM from the top of mouse chromosome 2. In mouse, Mial was also expressed in the cochlea and the vestibule of the inner ear, as well as in brain, eye, limb, and ovary. Expression...... in mammalian cell cultures showed that MIAL is translated as an approximately 15-kDa polypeptide that is assembled into a covalently linked homodimer, modified by sulfation, and secreted from the cells via the Golgi apparatus. In the human MIAL gene, a frequent polymorphism was discovered in the translation...

  5. RASSF6; the Putative Tumor Suppressor of the RASSF Family

    Directory of Open Access Journals (Sweden)

    Hiroaki Iwasa

    2015-12-01

    Full Text Available Humans have 10 genes that belong to the Ras association (RA domain family (RASSF. Among them, RASSF7 to RASSF10 have the RA domain in the N-terminal region and are called the N-RASSF proteins. In contradistinction to them, RASSF1 to RASSF6 are referred to as the C-RASSF proteins. The C-RASSF proteins have the RA domain in the middle region and the Salvador/RASSF/Hippo domain in the C-terminal region. RASSF6 additionally harbors the PSD-95/Discs large/ZO-1 (PDZ-binding motif. Expression of RASSF6 is epigenetically suppressed in human cancers and is generally regarded as a tumor suppressor. RASSF6 induces caspase-dependent and -independent apoptosis. RASSF6 interacts with mammalian Ste20-like kinases (homologs of Drosophila Hippo and cross-talks with the Hippo pathway. RASSF6 binds MDM2 and regulates p53 expression. The interactions with Ras and Modulator of apoptosis 1 (MOAP1 are also suggested by heterologous protein-protein interaction experiments. RASSF6 regulates apoptosis and cell cycle through these protein-protein interactions, and is implicated in the NF-κB and JNK signaling pathways. We summarize our current knowledge about RASSF6 and discuss what common and different properties RASSF6 and the other C-RASSF proteins have.

  6. Further evidence for poly-ADP-ribosylated histones as DNA suppressors

    International Nuclear Information System (INIS)

    Yu, F.L.; Geronimo, I.H.; Bender, W.; Meginniss, K.E.

    1986-01-01

    For many years histones have been considered to be the gene suppressors in eukaryotic cells. Recently, the authors have found strong evidence indicating that poly-ADP-ribosylated histones, rather than histones, are the potent inhibitors of DNA-dependent RNA synthesis. They now report additional evidence for this concept: 1) using histone inhibitor isolated directly from nuclei, the authors are able to confirm their earlier findings that the inhibitor substances are sensitive to pronase, snake venom phosphodiesterase digestion and 0.1N KOH hydrolysis, and are resistant to DNase I and RNase A digestion, 2) the O.D. 260/O.D.280 ratio of the histone inhibitor is between pure protein and nuclei acid, suggesting the inhibitor substance is a nucleoprotein hybrid. This result directly supports the fact that the isolated histone inhibitor is radioactive poly (ADP-ribose) labeled, 3) commercial histones show big differences in inhibitor activity. The authors believe this reflects the variation in poly-ADP-ribosylation among commercial histones, and 4) 0.1N KOH hydrolysis eliminates the poly (ADP-ribose) radioactivity from the acceptor proteins as well as histone inhibitor activity. Yet, on gel, the inhibitor shows identical histone bands and stain intensity before and after hydrolysis, indicating the histones per se are qualitatively and quantitatively unaffected by alkaline treatment. This result strongly suggests that histones themselves are not capable of inhibiting DNA-dependent RNA synthesis

  7. miR-339-5p regulates the p53 tumor-suppressor pathway by targeting MDM2

    DEFF Research Database (Denmark)

    Jansson, M D; Djodji Damas, Nkerorema; Lees, M

    2014-01-01

    MicroRNAs (miRNAs) regulate many key cancer-relevant pathways and may themselves possess oncogenic or tumor-suppressor functions. Consequently, miRNA dysregulation has been shown to be a prominent feature in many human cancers. The p53 tumor suppressor acts as a negative regulator of cell prolife...... tumor cells. Furthermore, we show that a negative correlation between miR-339-5p and MDM2 expression exists in human cancer, implying that the interaction is important for cancer development.Oncogene advance online publication, 2 June 2014; doi:10.1038/onc.2014.130....

  8. Genetic association analysis of 30 genes related to obesity in a European American population.

    Science.gov (United States)

    Li, P; Tiwari, H K; Lin, W-Y; Allison, D B; Chung, W K; Leibel, R L; Yi, N; Liu, N

    2014-05-01

    Obesity, which is frequently associated with diabetes, hypertension and cardiovascular diseases, is primarily the result of a net excess of caloric intake over energy expenditure. Human obesity is highly heritable, but the specific genes mediating susceptibility in non-syndromic obesity remain unclear. We tested candidate genes in pathways related to food intake and energy expenditure for association with body mass index (BMI). We reanalyzed 355 common genetic variants of 30 candidate genes in seven molecular pathways related to obesity in 1982 unrelated European Americans from the New York Cancer Project. Data were analyzed by using a Bayesian hierarchical generalized linear model. The BMIs were log-transformed and then adjusted for covariates, including age, age(2), gender and diabetes status. The single-nucleotide polymorphisms (SNPs) were modeled as additive effects. With the stipulated adjustments, nine SNPs in eight genes were significantly associated with BMI: ghrelin (GHRL; rs35683), agouti-related peptide (AGRP; rs5030980), carboxypeptidase E (CPE; rs1946816 and rs4481204), glucagon-like peptide-1 receptor (GLP1R; rs2268641), serotonin receptors (HTR2A; rs912127), neuropeptide Y receptor (NPY5R;Y5R1c52), suppressor of cytokine signaling 3 (SOCS3; rs4969170) and signal transducer and activator of transcription 3 (STAT3; rs4796793). We also found a gender-by-SNP interaction (rs1745837 in HTR2A), which indicated that variants in the gene HTR2A had a stronger association with BMI in males. In addition, NPY1R was detected as having a significant gene effect even though none of the SNPs in this gene was significant. Variations in genes AGRP, CPE, GHRL, GLP1R, HTR2A, NPY1R, NPY5R, SOCS3 and STAT3 showed modest associations with BMI in European Americans. The pathways in which these genes participate regulate energy intake, and thus these associations are mechanistically plausible in this context.

  9. CFTR is a tumor suppressor gene in murine and human intestinal cancer

    NARCIS (Netherlands)

    Than, B. L. N.; Linnekamp, J. F.; Starr, T. K.; Largaespada, D. A.; Rod, A.; Zhang, Y.; Bruner, V.; Abrahante, J.; Schumann, A.; Luczak, T.; Niemczyk, A.; O'Sullivan, M. G.; Medema, J. P.; Fijneman, R. J. A.; Meijer, G. A.; van den Broek, E.; Hodges, C. A.; Scott, P. M.; Vermeulen, L.; Cormier, R. T.

    2016-01-01

    CFTR, the cystic fibrosis (CF) gene, encodes for the CFTR protein that plays an essential role in anion regulation and tissue homeostasis of various epithelia. In the gastrointestinal (GI) tract CFTR promotes chloride and bicarbonate secretion, playing an essential role in ion and acid-base

  10. Modification of barley powdery mildew resistance controlled by the gene M1-a212

    International Nuclear Information System (INIS)

    Torp, J.; Joergensen, J.H.

    1989-01-01

    Full text: The barley line Sultan 5 carries resistance gene M1-a12. Seeds were treated with EMS or NaN 3 . Among 10381 M 1 -spike progenies inoculated with M1-a12 a-virulent isolates of Erysiphe graminis, 25 segregated for less resistant infection type. Among 10 mutants analyzed, 9 had mutant allels of M1-a12 and one had a recessive mutant gene in a different locus acting as a ''suppressor'' of M1-a12. (author)

  11. Murine neonatal spleen contains natural T and non-T suppressor cells capable of inhibiting adult alloreactive and newborn autoreactive T-cell proliferation.

    Science.gov (United States)

    Hooper, D C; Hoskin, D W; Gronvik, K O; Murgita, R A

    1986-05-01

    The spleen of neonatal mice is known to be a rich source of cells capable of suppressing a variety of immune functions of adult lymphocytes in vitro. From such observations has emerged the concept that the gradual development in ability to express immune functions after birth is due in part to the parallel normal physiological decay of naturally occurring regulatory suppressor cells. There is, however, some confusion in the literature as to the exact nature of the newborn of the newborn inhibitory cell type(s). In contrast to most previous reports which detect only a single type of neonatal suppressor cell, usually a T cell, we show here that newborn spleen harbors both T and non-T inhibitory cells. Both types of suppressor cells could be shown to suppress the proliferative response of adult spleen to alloantigens as well as newborn T cells reacting against self-Ia antigen in the autologous mixed lymphocyte reaction (AMLR). Newborn suppressor T cells were characterized as being non-adherent to Ig-anti-Ig affinity columns, soybean agglutinin receptor negative (SBA-), and susceptible to lysis by anti-T-cell specific antiserum plus complement. Non-T suppressor cells were identified as non-phagocytic, SBA receptor positive (SBA+), and resistant to cytotoxic treatment with anti-T-cell antibodies and complement. The apparent controversy surrounding previous reports as to the T versus non-T nature of newborn suppressor cells can be reconciled by the present observation that both types of inhibitory cells coexist in the spleen. Furthermore, the demonstration that newborn suppressor cells can effectively regulate T-cell proliferative activity mediated by other newborn cells provides more direct support for the contention that such inhibitory cells play a physiological role in controlling immune responsiveness during early ontogeny.

  12. Natural killer activity and suppressor cells in irradiated mice repopulated with a mixture of cells from normal and 89Sr-treated donors

    International Nuclear Information System (INIS)

    Levy, E.M.; Kumar, V.; Bennett, M.

    1981-01-01

    Mice that have been injected with 89 Sr have fairly normal B and T cell function, but are abnormal in that they lack natural killer (NK) activity and other functions that require an intact bone marrow. These mice also have an increased potential for suppressor cell activity. We had previously shown that spleen cells from 89 Sr-treated mice could transfer low NK activity and increased suppressor cell function to lethally irradiated syngeneic recipients. To investigate the mechanisms involved in perpetuating these defects, groups of normal spleen or bone marrow cells. Recipients were assayed for their NK activity and suppressor cell function 5 to 14 wk later. it was found that the addition of normal cells in the donor inoculum resulted in normal NK activity. This indicates that low NK activity in 89 Sr-treated mice was not due to the presence of a suppressor cell that prevented NK cell generation. It was additionally found that low NK activity in recipient mice could be boosted by interferon inducers. This would indicate that NK activity in the recipients was not due to a lack of interferon-sensitive pre-NK cells. Suppressor cell function in recipient mice depended on the type and number of normal cells in the donor inoculum. Bone marrow cells were very efficient in overcoming the tendency to produce suppressor cells. It took approximately 20 times more normal spleen cells to produce the same results. The implications of these findings are discussed

  13. H-2-incompatible bone marrow chimeras produce donor-H-2-restricted Ly-2 suppressor T-cell factor(s)

    International Nuclear Information System (INIS)

    Noguchi, M.; Onoe, K.; Ogasawara, M.; Iwabuchi, K.; Geng, L.; Ogasawara, K.; Good, R.A.; Morikawa, K.

    1985-01-01

    To study adaptive-differentiation phenomena of T lymphocytes, suppressor T-cell factors (TsF) produced by Ly-2+ splenic T cells from fully allogeneic mouse bone marrow chimeras were analyzed. AKR mice irradiated and reconstituted with B10 marrow cells (B10----AKR chimeras) produced an Ly-2+ TsF after hyperimmunization with sheep erythrocytes. The TsF suppressed primary antibody responses (to sheep erythrocytes) generated with spleen cells of mice of H-2b haplotype but not those of H-2k haplotype. Thus, this suppressor factor was donor-H-2-restricted. The immunoglobulin heavy chain variable region gene (Igh-V)-restricting element was not involved in this form of suppression. Similar results were obtained when TsF from B6----BALB/c and BALB/c----B6 chimeras were analyzed. The TsF from B10----AKR chimeras suppressed responses of B10.A(3R) and B10.A(5R) mice but not those of B10.A(4R). This finding showed that identity between the factor-producing cells and target spleen cells is required on the left-hand side of the E beta locus of the H-2 region and that the putative I-Jb locus is not involved in this form of suppression. The present results support the postulate that post-thymic differentiation in the presence of continued or repeated stimulation with antigen and donor-derived antigen-presenting cells generates donor-H-2-restricted T-cell clones that may predominate within the repertoire of the specific antigen being presented

  14. The silencing suppressor (NSs) protein of the plant virus Tomato spotted wilt virus enhances heterologous protein expression and baculovirus pathogenicity in cells and lepidopteran insects.

    Science.gov (United States)

    de Oliveira, Virgínia Carla; da Silva Morgado, Fabricio; Ardisson-Araújo, Daniel Mendes Pereira; Resende, Renato Oliveira; Ribeiro, Bergmann Morais

    2015-11-01

    In this work, we showed that cell death induced by a recombinant (vAcNSs) Autographa californica multiple nucleopolyhedrovirus (AcMNPV) expressing the silencing suppressor (NSs) protein of Tomato spotted wilt virus (TSWV) was enhanced on permissive and semipermissive cell lines. The expression of a heterologous gene (firefly luciferase) during co-infection of insect cells with vAcNSs and a second recombinant baculovirus (vAgppolhfluc) was shown to increase when compared to single vAgppolhfluc infections. Furthermore, the vAcNSs mean time-to-death values were significantly lower than those for wild-type AcMNPV on larvae of Spodoptera frugiperda and Anticarsia gemmatalis. These results showed that the TSWV-NSs protein could efficiently increase heterologous protein expression in insect cells as well as baculovirus pathogenicity and virulence, probably by suppressing the gene-silencing machinery in insects.

  15. Alternative Polyadenylation of Tumor Suppressor Genes in Small Intestinal Neuroendocrine Tumors

    OpenAIRE

    Rehfeld, Anders; Plass, Mireya; Døssing, Kristina; Knigge, Ulrich; Kjær, Andreas; Krogh, Anders; Friis-Hansen, Lennart

    2014-01-01

    The tumorigenesis of small intestinal neuroendocrine tumors (SI-NETs) is poorly understood. Recent studies have associated alternative polyadenylation (APA) with proliferation, cell transformation, and cancer. Polyadenylation is the process in which the pre-messenger RNA is cleaved at a polyA site and a polyA tail is added. Genes with two or more polyA sites can undergo APA. This produces two or more distinct mRNA isoforms with different 3′ untranslated regions. Additionally, APA can also pro...

  16. Prolonged re-expression of the hypermethylated gene EPB41L3 using artificial transcription factors and epigenetic drugs

    NARCIS (Netherlands)

    Huisman, Christian; van der Wijst, Monique G. P.; Falahi, Fahimeh; Overkamp, Juul; Karsten, Gellert; Terpstra, Martijn M.; Kok, Klaas; van der Zee, Ate G. J.; Schuuring, Ed; Wisman, G. Bea A.; Rots, Marianne G.

    2015-01-01

    Epigenetic silencing of tumor suppressor genes (TSGs) is considered a significant event in the progression of cancer. For example, EPB41L3, a potential biomarker in cervical cancer, is often silenced by cancer-specific promoter methylation. Artificial transcription factors (ATFs) are unique tools to

  17. Identification of a common microdeletion cluster in 7q21.3 subband among patients with myeloid leukemia and myelodysplastic syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Asou, Hiroya; Matsui, Hirotaka; Ozaki, Yuko; Nagamachi, Akiko; Nakamura, Megumi; Aki, Daisuke [Department of Molecular Oncology and Leukemia Program Project, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553 (Japan); Inaba, Toshiya, E-mail: tinaba@hiroshima-u.ac.jp [Department of Molecular Oncology and Leukemia Program Project, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553 (Japan)

    2009-05-29

    Monosomy 7 and interstitial deletions in the long arm of chromosome 7 (-7/7q-) is a common nonrandom chromosomal abnormality found frequently in myeloid disorders including acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and juvenile myelomonocytic leukemia (JMML). Using a short probe-based microarray comparative genomic hybridization (mCGH) technology, we identified a common microdeletion cluster in 7q21.3 subband, which is adjacent to 'hot deletion region' thus far identified by conventional methods. This common microdeletion cluster contains three poorly characterized genes; Samd9, Samd9L, and a putative gene LOC253012, which we named Miki. Gene copy number assessment of three genes by real-time PCR revealed heterozygous deletion of these three genes in adult patients with AML and MDS at high frequency, in addition to JMML patients. Miki locates to mitotic spindles and centrosomes and downregulation of Miki by RNA interference induced abnormalities in mitosis and nuclear morphology, similar to myelodysplasia. In addition, a recent report indicated Samd9 as a tumor suppressor. These findings indicate the usefulness of the short probe-based CGH to detect microdeletions. The three genes located to 7q21.3 would be candidates for myeloid tumor-suppressor genes on 7q.

  18. Expression of PML tumor suppressor in A 431 cells reduces cellular growth by inhibiting the epidermal growth factor receptor expression

    International Nuclear Information System (INIS)

    Vallian, S.; Chang, K.S.

    2004-01-01

    Our previous studies showed that the promyelocytic leukemia, PML, protein functions as a cellular and growth suppressor. Transient expression of PML was also found to repress the activity of the epidermal growth factor receptor gene promoter. In this study we have examined the effects of PML on A431 cells, which express a high level of + protein. The PML gene was introduced into the cells using the adenovirus-mediated gene transfer system. Western blot analysis on the extracts from the cells expressing PML showed a significant repression in the expression of the epidermal growth factor receptor protein. The cells were examined for growth and DNA synthesis. The data showed a marked reduction in both growth and DNA synthesis rate in the cells expressing PML compared with the control cells. Furthermore, in comparison with the controls, the cells expressing PML were found to be more in G1 phase, fewer in S and about the same number in the G2/M phase. This data clearly demonstrated that the repression of epidermal growth factor receptor expression in A 431 cells by PML was associated with inhibition of cell growth and alteration of the cell cycle distribution, suggesting a novel mechanism for the known growth inhibitory effects of PML

  19. Deletion analysis of the expression of rRNA genes and associated tRNA genes carried by a lambda transducing bacteriophage

    International Nuclear Information System (INIS)

    Morgan, E.A.; Nomura, M.

    1979-01-01

    Transducing phage lambda ilv5 carries genes for rRNA's, spacer tRNA's (tRNA 1 /sup Ile/ and tRNA/sub 1B//sup Ala/), and two other tRNA's (tRNA 1 /sup Asp/ and tRNA/sup Trp/). We have isolated a mutant of lambda ilv5, lambda ilv5su7, which carries an amber suppressor mutation in the tRNA/sup Trp/ gene. A series of deletion mutants were isolated from the lambda ilv5su7 phage. Genetic and biochemical analyses of these deletion mutants have confirmed our previous conclusion that the genes for tRNA 1 /sup Asp/ and tRNA/sup Trp/ located at the distal end of the rRNA operon (rrnC) are cotranscribed with other rRNA genes in that operon. In addition, these deletions were used to define roughly the physical location of the promoter(s) of the rRNA operon carried by the lambda ilv5su7 transducing phage

  20. Clinical Impact of TP53 Gene Mutations in Diffuse Large B-Cell Lymphoma (DLBCL)

    DEFF Research Database (Denmark)

    Young, Ken H; Patten, Nancy; Truong, Sim

    2009-01-01

    Mutations of the TP53 tumor suppressor gene are associated with a poor clinical outcome in DLBCL patients treated with CHOP. The impact of TP53 mutations on clinical outcome of DLBCL patients treated with Rituxan-CHOP has not been comprehensively analyzed. The purpose of this study was to analyze...