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Sample records for suppressor gene located

  1. Gene Locater

    DEFF Research Database (Denmark)

    Anwar, Muhammad Zohaib; Sehar, Anoosha; Rehman, Inayat-Ur

    2012-01-01

    software's for calculating recombination frequency is mostly limited to the range and flexibility of this type of analysis. GENE LOCATER is a fully customizable program for calculating recombination frequency, written in JAVA. Through an easy-to-use interface, GENE LOCATOR allows users a high degree...... of flexibility in calculating genetic linkage and displaying linkage group. Among other features, this software enables user to identify linkage groups with output visualized graphically. The program calculates interference and coefficient of coincidence with elevated accuracy in sample datasets. AVAILABILITY...

  2. 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)

  3. 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

  4. 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

  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. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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...

  11. 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

  12. 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.

  13. 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.

  14. Nuclear location of tumor suppressor protein maspin inhibits proliferation of breast cancer cells without affecting proliferation of normal epithelial cells

    International Nuclear Information System (INIS)

    Machowska, Magdalena; Wachowicz, Katarzyna; Sopel, Mirosław; Rzepecki, Ryszard

    2014-01-01

    Maspin, which is classified as a tumor suppressor protein, is downregulated in many types of cancer. Several studies have suggested potential anti-proliferative activity of maspin as well as sensitizing activity of maspin for therapeutic cytotoxic agents in breast cancer tissue culture and animal models. All of the experimental data gathered so far have been based on studies with maspin localized cytoplasmically, while maspin in breast cancer tumor cells may be located in the cytoplasm, nucleus or both. In this study, the effect of maspin cytoplasmic and nuclear location and expression level on breast cancer proliferation and patient survival was studied. Tissue sections from 166 patients with invasive ductal breast cancer were stained by immunohistochemistry for maspin and Ki-67 protein. The localization and expression level of maspin were correlated with estimated patient overall survival and percent of Ki-67-positive cells. In further studies, we created constructs for transient transfection of maspin into breast cancer cells with targeted cytoplasmic and nuclear location. We analyzed the effect of maspin location in normal epithelial cell line MCF10A and three breast cancer cell lines - MCF-7, MDA-MB-231 and SKBR-3 - by immunofluorescence and proliferation assay. We observed a strong positive correlation between moderate and high nuclear maspin level and survival of patients. Moreover, a statistically significant negative relationship was observed between nuclear maspin and Ki-67 expression in patients with invasive ductal breast cancer. Spearman’s correlation analysis showed a negative correlation between level of maspin localized in nucleus and percentage of Ki-67 positive cells. No such differences were observed in cells with cytoplasmic maspin. We found a strong correlation between nuclear maspin and loss of Ki-67 protein in breast cancer cell lines, while there was no effect in normal epithelial cells from breast. The anti-proliferative effect of nuclear

  15. Nuclear location of tumor suppressor protein maspin inhibits proliferation of breast cancer cells without affecting proliferation of normal epithelial cells

    Science.gov (United States)

    2014-01-01

    Background Maspin, which is classified as a tumor suppressor protein, is downregulated in many types of cancer. Several studies have suggested potential anti-proliferative activity of maspin as well as sensitizing activity of maspin for therapeutic cytotoxic agents in breast cancer tissue culture and animal models. All of the experimental data gathered so far have been based on studies with maspin localized cytoplasmically, while maspin in breast cancer tumor cells may be located in the cytoplasm, nucleus or both. In this study, the effect of maspin cytoplasmic and nuclear location and expression level on breast cancer proliferation and patient survival was studied. Methods Tissue sections from 166 patients with invasive ductal breast cancer were stained by immunohistochemistry for maspin and Ki-67 protein. The localization and expression level of maspin were correlated with estimated patient overall survival and percent of Ki-67-positive cells. In further studies, we created constructs for transient transfection of maspin into breast cancer cells with targeted cytoplasmic and nuclear location. We analyzed the effect of maspin location in normal epithelial cell line MCF10A and three breast cancer cell lines - MCF-7, MDA-MB-231 and SKBR-3 - by immunofluorescence and proliferation assay. Results We observed a strong positive correlation between moderate and high nuclear maspin level and survival of patients. Moreover, a statistically significant negative relationship was observed between nuclear maspin and Ki-67 expression in patients with invasive ductal breast cancer. Spearman’s correlation analysis showed a negative correlation between level of maspin localized in nucleus and percentage of Ki-67 positive cells. No such differences were observed in cells with cytoplasmic maspin. We found a strong correlation between nuclear maspin and loss of Ki-67 protein in breast cancer cell lines, while there was no effect in normal epithelial cells from breast. The anti

  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. 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).

  18. 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.

  19. 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.

  20. 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

    Full Text Available Abstract Background To identify new and useful candidate biomarkers in head and neck squamous cell carcinoma (HNSCC, we performed a genome-wide survey and found that Myelin and lymphocyte-associated protein (MAL was a gene that was markedly down-regulated in HNSCC. Hence, we investigated the mechanism of MAL silencing and the effects of MAL on the proliferation, invasion, and apoptotic potential in HNSCC. Results MAL was significantly down-regulated in 91.7% of HNSCC specimens at the mRNA level as compared with adjacent normal tissues (P = 0.0004. Moreover, the relative transcript levels of the MAL gene were remarkably decreased by five-fold in nine HNSCC cell lines as compared with normal head and neck epithelium cells. MAL gene expression was restored in 44%, 67%, and 89% in HNSCC cell lines treated with TSA, 5-Aza-dC, and TSA plus 5-Aza-dC, respectively. Furthermore, bisulfate-treated DNA sequencing demonstrated that the two CpG islands (that is, M1 and M2 located in MAL promoter region were completely methylated in the HNSCC cell lines (CpG methylated ratio was more than 90%, and only one CpG island (that is, M1 was partially methylated in HNSCC tissues (CpG methylated ratio between 20% and 90%. A significant reduction in cell proliferation and a change in the cell cycle profile were also observed in MAL transfectants. Matrigel assay demonstrated that the invasiveness of HNSCC cells significantly decreased. A significant increase in the population of apoptotic cells was observed in MAL transfected cells. The exogenous expression of the MAL gene suppressed malignant phenotypes, while the cell death induced by MAL gene transfer was a result of apoptosis as demonstrated by the induction of cleavage of the poly (that is, ADP-ribose polymerase. Additionally, tumor growth was suppressed in cells expressing MAL as compared with cells not expressing MAL. Conclusion Our data suggest that the epigenetic inactivation of MAL, as a candidate tumor

  1. 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

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

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

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    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.

  9. 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.

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

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    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.

  11. 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.

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

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    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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Visualizing conserved gene location across microbe genomes

    Science.gov (United States)

    Shaw, Chris D.

    2009-01-01

    This paper introduces an analysis-based zoomable visualization technique for displaying the location of genes across many related species of microbes. The purpose of this visualizatiuon is to enable a biologist to examine the layout of genes in the organism of interest with respect to the gene organization of related organisms. During the genomic annotation process, the ability to observe gene organization in common with previously annotated genomes can help a biologist better confirm the structure and function of newly analyzed microbe DNA sequences. We have developed a visualization and analysis tool that enables the biologist to observe and examine gene organization among genomes, in the context of the primary sequence of interest. This paper describes the visualization and analysis steps, and presents a case study using a number of Rickettsia genomes.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

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

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    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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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…

  13. 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

  14. 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....

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. 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...

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. High Velocity Jet Noise Source Location and Reduction. Task 3 - Experimental Investigation of Suppression Principles. Volume I. Suppressor Concepts Optimization

    Science.gov (United States)

    1978-12-01

    25. Predicted Vs. Measured PNL Directivity for an 8-Lobe Daisy Suppressor ( Aerotrain ); Va = 0. 168 4-26. Predicted Vs. Measured PNL Directivity for...of Configurations for Verification of Suppression Principles. 137 4-2. PNL Data/Theory Comparison for Bertin Aerotrain Test Series; 400-ft Sideline...obtained from the scale-model tests con- ducted in Task 3 and from the Aerotrain tests conducted in Task 4 of the present program. Comparisons were

  14. 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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

  18. 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

  19. 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

  20. 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)

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

    Directory of Open Access Journals (Sweden)

    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

  2. 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

  3. 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.

  4. 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.

  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. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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...

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

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    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

  3. 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...

  4. 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.

  5. 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

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    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.

  6. 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.

  7. 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

  8. 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) ...

  9. 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

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

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    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.

  11. 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

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

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    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.

  13. 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)

  14. 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.

  15. 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...

  16. A targeted constitutive mutation in the APC tumor suppressor gene underlies mammary but not intestinal tumorigenesis.

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    Claudia Gaspar

    2009-07-01

    Full Text Available Germline mutations in the adenomatous polyposis coli (APC gene are responsible for familial adenomatous polyposis (FAP, an autosomal dominant hereditary predisposition to the development of multiple colorectal adenomas and of a broad spectrum of extra-intestinal tumors. Moreover, somatic APC mutations play a rate-limiting and initiating role in the majority of sporadic colorectal cancers. Notwithstanding its multifunctional nature, the main tumor suppressing activity of the APC gene resides in its ability to regulate Wnt/beta-catenin signaling. Notably, genotype-phenotype correlations have been established at the APC gene between the length and stability of the truncated proteins encoded by different mutant alleles, the corresponding levels of Wnt/beta-catenin signaling activity they encode for, and the incidence and distribution of intestinal and extra-intestinal tumors. Here, we report a novel mouse model, Apc1572T, obtained by targeting a truncated mutation at codon 1572 in the endogenous Apc gene. This hypomorphic mutant allele results in intermediate levels of Wnt/beta-catenin signaling activation when compared with other Apc mutations associated with multifocal intestinal tumors. Notwithstanding the constitutive nature of the mutation, Apc(+/1572T mice have no predisposition to intestinal cancer but develop multifocal mammary adenocarcinomas and subsequent pulmonary metastases in both genders. The histology of the Apc1572T primary mammary tumours is highly heterogeneous with luminal, myoepithelial, and squamous lineages and is reminiscent of metaplastic carcinoma of the breast in humans. The striking phenotype of Apc(+/1572T mice suggests that specific dosages of Wnt/beta-catenin signaling activity differentially affect tissue homeostasis and initiate tumorigenesis in an organ-specific fashion.

  17. NKL homeobox gene MSX1 acts like a tumor suppressor in NK-cell leukemia.

    Science.gov (United States)

    Nagel, Stefan; Pommerenke, Claudia; Meyer, Corinna; Kaufmann, Maren; MacLeod, Roderick A F; Drexler, Hans G

    2017-09-15

    NKL homeobox gene MSX1 is physiologically expressed in lymphoid progenitors and subsequently downregulated in developing T- and B-cells. In contrast, elevated expression levels of MSX1 persist in mature natural killer (NK)-cells, indicating a functional role in this compartment. While T-cell acute lymphoblastic leukemia (T-ALL) subsets exhibit aberrant overexpression of MSX1, we show here that in malignant NK-cells the level of MSX1 transcripts is aberrantly downregulated. Chromosomal deletions at 4p16 hosting the MSX1 locus have been described in NK-cell leukemia patients. However, NK-cell lines analyzed here showed normal MSX1 gene configurations, indicating that this aberration might be uncommon. To identify alternative MSX1 regulatory mechanisms we compared expression profiling data of primary normal NK-cells and malignant NK-cell lines. This procedure revealed several deregulated genes including overexpressed IRF4, MIR155HG and MIR17HG and downregulated AUTS2, EP300, GATA3 and HHEX. As shown recently, chromatin-modulator AUTS2 is overexpressed in T-ALL subsets where it mediates aberrant transcriptional activation of MSX1. Here, our data demonstrate that in malignant NK-cell lines AUTS2 performed MSX1 activation as well, but in accordance with downregulated MSX1 transcription therein we detected reduced AUTS2 expression, a small genomic deletion at 7q11 removing exons 3 and 4, and truncating mutations in exon 1. Moreover, genomic profiling and chromosomal analyses of NK-cell lines demonstrated amplification of IRF4 at 6p25 and deletion of PRDM1 at 6q21, highlighting their potential oncogenic impact. Functional analyses performed via knockdown or forced expression of these genes revealed regulatory network disturbances effecting downregulation of MSX1 which may underlie malignant development in NK-cells.

  18. 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.

  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. 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. 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

  2. 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.

  3. 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

  4. 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

  5. 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...

  6. SUMOylation of the ING1b tumor suppressor regulates gene transcription

    DEFF Research Database (Denmark)

    Satpathy, Shankha; Guérillon, Claire; Kim, Tae-Sun

    2014-01-01

    members of histone deacetylase complexes, whereas ING3-5 are stoichiometric components of different histone acetyltransferase complexes. The INGs target these complexes to histone marks, thus acting as epigenetic regulators. ING proteins affect angiogenesis, apoptosis, DNA repair, metastasis......1b E195A), we further demonstrate that ING1b SUMOylation regulates the binding of ING1b to the ISG15 and DGCR8 promoters, consequently regulating ISG15 and DGCR8 transcription. These results suggest a role for ING1b SUMOylation in the regulation of gene transcription....

  7. 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.

  8. 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.

  9. Mutations in TP53 tumor suppressor gene in wood dust-related sinonasal cancer

    DEFF Research Database (Denmark)

    Holmila, Reetta; Bornholdt, Jette; Heikkilä, Pirjo

    2010-01-01

    The causal role of work-related exposure to wood dust in the development of sinonasal cancer has long been established by numerous epidemiologic studies. To study molecular changes in these tumors, we analyzed TP53 gene mutations in 358 sinonasal cancer cases with or without occupational exposure...... affected the ORs only slightly. Smoking did not influence the occurrence of TP53 mutation; however, it was associated with multiple mutations (p = 0.03). As far as we are aware, this is the first study to demonstrate a high prevalence of TP53 mutation-positive cases in a large collection of sinonasal...... cancers with data on occupational exposure. Our results indicate that mutational mechanisms, in particular TP53 mutations, are associated with work-related exposure to wood dust in sinonasal cancer....

  10. Apoptosis in neural crest cells by functional loss of APC tumor suppressor gene

    Science.gov (United States)

    Hasegawa, Sumitaka; Sato, Tomoyuki; Akazawa, Hiroshi; Okada, Hitoshi; Maeno, Akiteru; Ito, Masaki; Sugitani, Yoshinobu; Shibata, Hiroyuki; Miyazaki, Jun-ichi; Katsuki, Motoya; Yamauchi, Yasutaka; Yamamura, Ken-ichi; Katamine, Shigeru; Noda, Tetsuo

    2002-01-01

    Apc is a gene associated with familial adenomatous polyposis coli (FAP) and its inactivation is a critical step in colorectal tumor formation. The protein product, adenomatous polyposis coli (APC), acts to down-regulate intracellular levels of β-catenin, a key signal transducer in the Wnt signaling. Conditional targeting of Apc in the neural crest of mice caused massive apoptosis of cephalic and cardiac neural crest cells at about 11.5 days post coitum, resulting in craniofacial and cardiac anomalies at birth. Notably, the apoptotic cells localized in the regions where β-catenin had accumulated. In contrast to its role in colorectal epithelial cells, inactivation of APC leads to dysregulation of β-catenin/Wnt signaling with resultant apoptosis in certain tissues including neural crest cells. PMID:11756652

  11. 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

  12. 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

  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. Sexy gene conversions: locating gene conversions on the X-chromosome.

    Science.gov (United States)

    Lawson, Mark J; Zhang, Liqing

    2009-08-01

    Gene conversion can have a profound impact on both the short- and long-term evolution of genes and genomes. Here, we examined the gene families that are located on the X-chromosomes of human (Homo sapiens), chimpanzee (Pan troglodytes), mouse (Mus musculus) and rat (Rattus norvegicus) for evidence of gene conversion. We identified seven gene families (WD repeat protein family, Ferritin Heavy Chain family, RAS-related Protein RAB-40 family, Diphosphoinositol polyphosphate phosphohydrolase family, Transcription Elongation Factor A family, LDOC1-related family, Zinc Finger Protein ZIC, and GLI family) that show evidence of gene conversion. Through phylogenetic analyses and synteny evidence, we show that gene conversion has played an important role in the evolution of these gene families and that gene conversion has occurred independently in both primates and rodents. Comparing the results with those of two gene conversion prediction programs (GENECONV and Partimatrix), we found that both GENECONV and Partimatrix have very high false negative rates (i.e. failed to predict gene conversions), which leads to many undetected gene conversions. The combination of phylogenetic analyses with physical synteny evidence exhibits high resolution in the detection of gene conversions.

  15. 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...

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Chromosomal location of the human gene for DNA polymerase β

    International Nuclear Information System (INIS)

    McBride, O.W.; Zmudzka, B.Z.; Wilson, S.H.

    1987-01-01

    Inhibition studies indicate that DNA polymerase β has a synthetic role in DNA repair after exposure of mammalian cells to some types of DNA-damaging agents. The primary structure of the enzyme is highly conserved in vertebrates, and nearly full-length cDNAs for the enzyme were recently cloned from mammalian cDNA libraries. Southern blot analysis of DNA from a panel of human-rodent somatic cell hybrids, using portions of the cDNA as probe, indicates that the gene for human DNA polymerase β is single copy and located on the short arm or proximal long arm of chromosome 8 (8pter-8q22). A restriction fragment length polymorphism (RFLP) was detected in normal individuals by using a probe from the 5' end of the cDNA, and this RFLP probably is due to an insertion or duplication of DNA in 20-25% of the population. This restriction site can be used as one marker for chromosome 8 genetic linkage studies and for family studies of traits potentially involving this DNA repair gene

  4. Location of gene expression in CNS using hybridization histochemistry

    International Nuclear Information System (INIS)

    Penschow, J.D.; Haralambidis, J.; Aldred, P.; Tregear, G.W.; Coghlan, J.P.

    1986-01-01

    The pursuit of improvements in sensitivity, specificity, and resolution has resulted in a myriad of published procedures designed for a variety of applications and of seemingly increasing complexity. The choice of technique now available, through significant recent technological advances, includes nonisotopic cDNA probe labels, single-stranded RNA (Riboprobe), and synthetic oligonucleotides as probes, in addition to the now familiar radiolabeled cDNA probes. The authors' aim is to simplify this choice by describing a convenient method applicable to the location of specific mRNA in brain and other tissues by either cDNA or synthetic oligodeoxyribonucleotide probes. The procedure is based on a /sup 32/P probe label which enables detection of the mRNA-DNA hybrids on X-ray fail autoradiographs of frozen sections within 48 hr of tissue collection. Single, labeled cells can be located in heterogeneous tissues in subsequent short exposure liquid emulsion autoradiographs. This technique has been used successfully over a period of 5 years on tissues as diverse as whole small animals, sheep brain, rat thyroid, and human tumors. Deproteination procedures employed with other methods, which have been found to be unnecessary for /sup 32/P, are not included, thus simplifying the procedure. The use of synthetic oligodeoxyribonucleotides is emphasized as their choice of probes for the reasons outlined. Apart from providing an escape route from dependence on a molecular biology laboratory, discriminating sequences of similar gene products can be synthesized and localized so that single cells within small groups can be further characterized by their biosynthetic function

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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.

  14. Locating a modifier gene of Ovum mutant through crosses between ...

    Indian Academy of Sciences (India)

    modifier gene of Om in the B6 background. [Tan J., Song ... should be half the rate of those from the normal crosses,. B6 (+/+) ... the genetic background of the B6 strain. The purpose of .... Smirnov test (P > 0.05) and the reproductive rate of N2.

  15. 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.

  16. Tsw gene-based resistance is triggered by a functional RNA silencing suppressor protein of the Tomato spotted wilt virus

    NARCIS (Netherlands)

    Ronde, de D.; Butterbach, P.B.E.; Lohuis, H.; Hedil, M.; Lent, van J.W.M.; Kormelink, R.J.M.

    2013-01-01

    As a result of contradictory reports, the avirulence (Avr) determinant that triggers Tsw gene-based resistance in Capsicum annuum against the Tomato spotted wilt virus (TSWV) is still unresolved. Here, the N and NSs genes of resistance-inducing (RI) and resistance-breaking (RB) isolates were cloned

  17. Caffeine mediates sustained inactivation of breast cancer-associated myofibroblasts via up-regulation of tumor suppressor genes.

    Directory of Open Access Journals (Sweden)

    Mysoon M Al-Ansari

    Full Text Available BACKGROUND: Active cancer-associated fibroblasts (CAFs or myofibroblasts play important roles not only in the development and progression of breast carcinomas, but also in their prognosis and treatment. Therefore, targeting these cells through suppressing their supportive procarcinogenic paracrine effects is mandatory for improving the current therapies that are mainly targeting tumor cells. To this end, we investigated the effect of the natural and pharmacologically safe molecule, caffeine, on CAF cells and their various procarcinogenic effects. METHODOLOGY/PRINCIPAL FINDINGS: We have shown here that caffeine up-regulates the tumor suppressor proteins p16, p21, p53 and Cav-1, and reduces the expression/secretion of various cytokines (IL-6, TGF-β, SDF-1 and MMP-2, and down-regulates α-SMA. Furthermore, caffeine suppressed the migratory/invasiveness abilities of CAF cells through PTEN-dependent Akt/Erk1/2 inactivation. Moreover, caffeine reduced the paracrine pro-invasion/-migration effects of CAF cells on breast cancer cells. These results indicate that caffeine can inactivate breast stromal myofibroblasts. This has been confirmed by showing that caffeine also suppresses the paracrine pro-angiogenic effect of CAF cells through down-regulating HIF-1αand its downstream effector VEGF-A. Interestingly, these effects were sustained in absence of caffeine. CONCLUSION/SIGNIFICANCE: The present findings provide a proof of principle that breast cancer myofibroblasts can be inactivated, and thereby caffeine may provide a safe and effective prevention against breast tumor growth/recurrence through inhibition of the procarcinogenic effects of active stromal fibroblasts.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. Presymptomatic breast cancer in Egypt: role of BRCA1 and BRCA2 tumor suppressor genes mutations detection

    Directory of Open Access Journals (Sweden)

    Hashishe Mervat M

    2010-06-01

    Full Text Available Abstract Background Breast cancer is one of the most common diseases affecting women. Inherited susceptibility genes, BRCA1 and BRCA2, are considered in breast, ovarian and other common cancers etiology. BRCA1 and BRCA2 genes have been identified that confer a high degree of breast cancer risk. Objective Our study was performed to identify germline mutations in some exons of BRCA1 and BRCA2 genes for the early detection of presymptomatic breast cancer in females. Methods This study was applied on Egyptian healthy females who first degree relatives to those, with or without a family history, infected with breast cancer. Sixty breast cancer patients, derived from 60 families, were selected for molecular genetic testing of BRCA1 and BRCA2 genes. The study also included 120 healthy first degree female relatives of the patients, either sisters and/or daughters, for early detection of presymptomatic breast cancer mutation carriers. Genomic DNA was extracted from peripheral blood lymphocytes of all the studied subjects. Universal primers were used to amplify four regions of the BRCA1 gene (exons 2,8,13 and 22 and one region (exon 9 of BRCA2 gene using specific PCR. The polymerase chain reaction was carried out. Single strand conformation polymorphism assay and heteroduplex analysis were used to screen for mutations in the studied exons. In addition, DNA sequencing of the normal and mutated exons were performed. Results Mutations in both BRCA1 and BRCA2 genes were detected in 86.7% of the families. Current study indicates that 60% of these families were attributable to BRCA1 mutations, while 26.7% of them were attributable to BRCA2 mutations. Results showed that four mutations were detected in the BRCA1 gene, while one mutation was detected in the BRCA2 gene. Asymptomatic relatives, 80(67% out of total 120, were mutation carriers. Conclusions BRCA1 and BRCA2 genes mutations are responsible for a significant proportion of breast cancer. BRCA mutations

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

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    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.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. Genetic modelling of PIM proteins in cancer: proviral tagging, cooperation with oncogenes, tumor suppressor genes and carcinogens.

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    Enara eAguirre

    2014-05-01

    Full Text Available The PIM proteins, which were initially discovered as proviral insertion sites in Moloney murine leukemia virus infection, are a family of highly homologous serine/threonine kinases that have been reported to be overexpressed in hematological malignancies and solid tumors. The PIM proteins have also been associated with metastasis and overall treatment responses and implicated in the regulation of apoptosis, metabolism, the cell cycle, and homing and migration, which makes these proteins interesting targets for anticancer drug discovery. The use of retroviral insertional mutagenesis and refined approaches such as complementation tagging has allowed the identification of myc, pim and a third group of genes (including bmi1 and gfi1 as complementing genes in lymphomagenesis. Moreover, mouse modeling of human cancer has provided an understanding of the molecular pathways that are involved in tumor initiation and progression at the physiological level. In particular, genetically modified mice have allowed researchers to further elucidate the role of each of the Pim isoforms in various tumor types. PIM kinases have been identified as weak oncogenes because experimental overexpression in lymphoid tissue, prostate and liver induces tumors at a relatively low incidence and with a long latency. However, very strong synergistic tumorigenicity between Pim1/2 and c-Myc and other oncogenes has been observed in lymphoid tissues. Mouse models have also been used to study whether the inhibition of specific PIM isoforms is required to prevent carcinogen-induced sarcomas, indicating that the absence of Pim2 and Pim3 greatly reduces sarcoma growth and bone invasion; the extent of this effect is similar to that observed in the absence of all 3 isoforms. This review will summarize some of the animal models that have been used to understand the isoform-specific contribution of PIM kinases to tumorigenesis.

  18. The tumor suppressor homolog in fission yeast, myh1+, displays a strong interaction with the checkpoint gene rad1+

    International Nuclear Information System (INIS)

    Jansson, Kristina; Warringer, Jonas; Farewell, Anne; Park, Han-Oh; Hoe, Kwang-Lae; Kim, Dong-Uk; Hayles, Jacqueline; Sunnerhagen, Per

    2008-01-01

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1 + , we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway

  19. 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

  20. 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.

  1. 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)

  2. Chromosomal location and nucleotide sequence of the Escherichia coli dapA gene.

    Science.gov (United States)

    Richaud, F; Richaud, C; Ratet, P; Patte, J C

    1986-04-01

    In Escherichia coli, the first enzyme of the diaminopimelate and lysine pathway is dihydrodipicolinate synthetase, which is feedback-inhibited by lysine and encoded by the dapA gene. The location of the dapA gene on the bacterial chromosome has been determined accurately with respect to the neighboring purC and dapE genes. The complete nucleotide sequence and the transcriptional start of the dapA gene were determined. The results show that dapA consists of a single cistron encoding a 292-amino acid polypeptide of 31,372 daltons.

  3. Chromosomal location and nucleotide sequence of the Escherichia coli dapA gene.

    OpenAIRE

    Richaud, F; Richaud, C; Ratet, P; Patte, J C

    1986-01-01

    In Escherichia coli, the first enzyme of the diaminopimelate and lysine pathway is dihydrodipicolinate synthetase, which is feedback-inhibited by lysine and encoded by the dapA gene. The location of the dapA gene on the bacterial chromosome has been determined accurately with respect to the neighboring purC and dapE genes. The complete nucleotide sequence and the transcriptional start of the dapA gene were determined. The results show that dapA consists of a single cistron encoding a 292-amin...

  4. Chromosomal location and nucleotide sequence of the Escherichia coli dapA gene.

    Science.gov (United States)

    Richaud, F; Richaud, C; Ratet, P; Patte, J C

    1986-01-01

    In Escherichia coli, the first enzyme of the diaminopimelate and lysine pathway is dihydrodipicolinate synthetase, which is feedback-inhibited by lysine and encoded by the dapA gene. The location of the dapA gene on the bacterial chromosome has been determined accurately with respect to the neighboring purC and dapE genes. The complete nucleotide sequence and the transcriptional start of the dapA gene were determined. The results show that dapA consists of a single cistron encoding a 292-amino acid polypeptide of 31,372 daltons. Images PMID:3514578

  5. 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

  6. Molecular cytogenetic characterization of canine histiocytic sarcoma: A spontaneous model for human histiocytic cancer identifies deletion of tumor suppressor genes and highlights influence of genetic background on tumor behavior

    Directory of Open Access Journals (Sweden)

    Abadie Jerome

    2011-05-01

    Full Text Available Abstract Background Histiocytic malignancies in both humans and dogs are rare and poorly understood. While canine histiocytic sarcoma (HS is uncommon in the general domestic dog population, there is a strikingly high incidence in a subset of breeds, suggesting heritable predisposition. Molecular cytogenetic profiling of canine HS in these breeds would serve to reveal recurrent DNA copy number aberrations (CNAs that are breed and/or tumor associated, as well as defining those shared with human HS. This process would identify evolutionarily conserved cytogenetic changes to highlight regions of particular importance to HS biology. Methods Using genome wide array comparative genomic hybridization we assessed CNAs in 104 spontaneously occurring HS from two breeds of dog exhibiting a particularly elevated incidence of this tumor, the Bernese Mountain Dog and Flat-Coated Retriever. Recurrent CNAs were evaluated further by multicolor fluorescence in situ hybridization and loss of heterozygosity analyses. Statistical analyses were performed to identify CNAs associated with tumor location and breed. Results Almost all recurrent CNAs identified in this study were shared between the two breeds, suggesting that they are associated more with the cancer phenotype than with breed. A subset of recurrent genomic imbalances suggested involvement of known cancer associated genes in HS pathogenesis, including deletions of the tumor suppressor genes CDKN2A/B, RB1 and PTEN. A small number of aberrations were unique to each breed, implying that they may contribute to the major differences in tumor location evident in these two breeds. The most highly recurrent canine CNAs revealed in this study are evolutionarily conserved with those reported in human histiocytic proliferations, suggesting that human and dog HS share a conserved pathogenesis. Conclusions The breed associated clinical features and DNA copy number aberrations exhibited by canine HS offer a valuable model

  7. Molecular cytogenetic characterization of canine histiocytic sarcoma: A spontaneous model for human histiocytic cancer identifies deletion of tumor suppressor genes and highlights influence of genetic background on tumor behavior

    International Nuclear Information System (INIS)

    Hedan, Benoit; Thomas, Rachael; Motsinger-Reif, Alison; Abadie, Jerome; Andre, Catherine; Cullen, John; Breen, Matthew

    2011-01-01

    Histiocytic malignancies in both humans and dogs are rare and poorly understood. While canine histiocytic sarcoma (HS) is uncommon in the general domestic dog population, there is a strikingly high incidence in a subset of breeds, suggesting heritable predisposition. Molecular cytogenetic profiling of canine HS in these breeds would serve to reveal recurrent DNA copy number aberrations (CNAs) that are breed and/or tumor associated, as well as defining those shared with human HS. This process would identify evolutionarily conserved cytogenetic changes to highlight regions of particular importance to HS biology. Using genome wide array comparative genomic hybridization we assessed CNAs in 104 spontaneously occurring HS from two breeds of dog exhibiting a particularly elevated incidence of this tumor, the Bernese Mountain Dog and Flat-Coated Retriever. Recurrent CNAs were evaluated further by multicolor fluorescence in situ hybridization and loss of heterozygosity analyses. Statistical analyses were performed to identify CNAs associated with tumor location and breed. Almost all recurrent CNAs identified in this study were shared between the two breeds, suggesting that they are associated more with the cancer phenotype than with breed. A subset of recurrent genomic imbalances suggested involvement of known cancer associated genes in HS pathogenesis, including deletions of the tumor suppressor genes CDKN2A/B, RB1 and PTEN. A small number of aberrations were unique to each breed, implying that they may contribute to the major differences in tumor location evident in these two breeds. The most highly recurrent canine CNAs revealed in this study are evolutionarily conserved with those reported in human histiocytic proliferations, suggesting that human and dog HS share a conserved pathogenesis. The breed associated clinical features and DNA copy number aberrations exhibited by canine HS offer a valuable model for the human counterpart, providing additional evidence towards

  8. 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.

  9. 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.

  10. 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

  11. Gene Discovery in Prostate Cancer: Functional Identification and Isolation of PAC-1, a Novel Tumor Suppressor Gene Within Chromosome 10p

    Science.gov (United States)

    1999-09-01

    I.. Zbar. B.. androle for the VHL gene in the development of hyperplasia in a number Lerman. I. I. Identification of the son Hippel-Lindau disease...of heterozy- gosity of chromosome 3p markers in small-cell lung cancer. Nature (Lond.). 329: eleguns produced hyperplasia in all tissues (26...central fibrovascular core lined by cuboidal tumor cells. Tumor weights were determined (Fig. 2d). At the end of 47 days after cells were

  12. Genes located in a chromosomal inversion are correlated with territorial song in white-throated sparrows.

    Science.gov (United States)

    Zinzow-Kramer, W M; Horton, B M; McKee, C D; Michaud, J M; Tharp, G K; Thomas, J W; Tuttle, E M; Yi, S; Maney, D L

    2015-11-01

    The genome of the white-throated sparrow (Zonotrichia albicollis) contains an inversion polymorphism on chromosome 2 that is linked to predictable variation in a suite of phenotypic traits including plumage color, aggression and parental behavior. Differences in gene expression between the two color morphs, which represent the two common inversion genotypes (ZAL2/ZAL2 and ZAL2/ZAL2(m) ), may therefore advance our understanding of the molecular underpinnings of these phenotypes. To identify genes that are differentially expressed between the two morphs and correlated with behavior, we quantified gene expression and terrirorial aggression, including song, in a population of free-living white-throated sparrows. We analyzed gene expression in two brain regions, the medial amygdala (MeA) and hypothalamus. Both regions are part of a 'social behavior network', which is rich in steroid hormone receptors and previously linked with territorial behavior. Using weighted gene co-expression network analyses, we identified modules of genes that were correlated with both morph and singing behavior. The majority of these genes were located within the inversion, showing the profound effect of the inversion on the expression of genes captured by the rearrangement. These modules were enriched with genes related to retinoic acid signaling and basic cellular functioning. In the MeA, the most prominent pathways were those related to steroid hormone receptor activity. Within these pathways, the only gene encoding such a receptor was ESR1 (estrogen receptor 1), a gene previously shown to predict song rate in this species. The set of candidate genes we identified may mediate the effects of a chromosomal inversion on territorial behavior. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  13. Restoration of tumor suppressor gene function by gene replacement or small molecule strategies for the treatment of small cell lung cancer

    DEFF Research Database (Denmark)

    Zandi, Roza

    2011-01-01

    markedly. PRIMA-1 Met also induced significant tumor growth delay in human SCLC mouse models without any signs of toxicity. These results suggest that PRIMA-1 Met can reactivate mutant p53 in SCLC cells, leading to the induction of apoptosis and tumor growth delay. To study the growth inhibitory effect......-mediated gene transfer in SCLC cells expressing various levels of endogenous FHIT protein. FHIT overexpression led to growth inhibition in all of the SCLC cell lines studied; although more effectively in cell lines with high levels of endogenous FHIT protein and transduction efficiency. FHIT-induced inhibition...... as potential therapeutic strategies for SCLC. However, as mutant p53 proteins tend to accumulate in SCLC cells, reintroduction of wild-type p53 may not be effective due to dominant-negative effects of the mutant protein. Therefore, a more effective approach would be to reactivate the endogenous mutant p53...

  14. A cII-dependent promoter is located within the Q gene of bacteriophage lambda.

    OpenAIRE

    Hoopes, B C; McClure, W R

    1985-01-01

    We have found a cII-dependent promoter, PaQ, within the Q gene of bacteriophage lambda. Transcription experiments and abortive initiation assays performed in vitro showed that the promoter strength and the cII affinity of PaQ were comparable to the other cII-dependent lambda promoters, PE and PI. The location and leftward direction of PaQ suggests a possible role in the delay of lambda late-gene expression by cII protein, a phenomenon that has been called cII-dependent inhibition. We have con...

  15. 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.

  16. Isoeugenol monooxygenase and its putative regulatory gene are located in the eugenol metabolic gene cluster in Pseudomonas nitroreducens Jin1.

    Science.gov (United States)

    Ryu, Ji-Young; Seo, Jiyoung; Unno, Tatsuya; Ahn, Joong-Hoon; Yan, Tao; Sadowsky, Michael J; Hur, Hor-Gil

    2010-03-01

    The plant-derived phenylpropanoids eugenol and isoeugenol have been proposed as useful precursors for the production of natural vanillin. Genes involved in the metabolism of eugenol and isoeugenol were clustered in region of about a 30 kb of Pseudomonas nitroreducens Jin1. Two of the 23 ORFs in this region, ORFs 26 (iemR) and 27 (iem), were predicted to be involved in the conversion of isoeugenol to vanillin. The deduced amino acid sequence of isoeugenol monooxygenase (Iem) of strain Jin1 had 81.4% identity to isoeugenol monooxygenase from Pseudomonas putida IE27, which also transforms isoeugenol to vanillin. Iem was expressed in E. coli BL21(DE3) and was found to lead to isoeugenol to vanillin transformation. Deletion and cloning analyses indicated that the gene iemR, located upstream of iem, is required for expression of iem in the presence of isoeugenol, suggesting it to be the iem regulatory gene. Reverse transcription, real-time PCR analyses indicated that the genes involved in the metabolism of eugenol and isoeugenol were differently induced by isoeugenol, eugenol, and vanillin.

  17. 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.

  18. Intellectual Ability in the Duchenne Muscular Dystrophy and Dystrophin Gene Mutation Location

    Directory of Open Access Journals (Sweden)

    Rasic Milic V.

    2014-12-01

    Full Text Available Duchenne muscular dystrophy (DMD is the most common form of muscular dystrophy during childhood. Mutations in dystrophin (DMD gene are also recognized as a cause of cognitive impairment. We aimed to determine the association between intelligence level and mutation location in DMD genes in Serbian patients with DMD. Forty-one male patients with DMD, aged 3 to 16 years, were recruited at the Clinic for Neurology and Psychiatry for Children and Youth in Belgrade, Serbia. All patients had defined DMD gene deletions or duplications [multiplex ligation- dependent probe amplification (MLPA, polymerase chain reaction (PCR] and cognitive status assessment (Wechsler Intelligence Scale for Children, Brunet-Lezine scale, Vineland-Doll scale. In 37 patients with an estimated full scale intelligence quotient (FSIQ, six (16.22% had borderline intelligence (70location when we assumed their functional consequence on dystrophin isoforms and when mutations in the 5’-untranslated region (5’UTR of Dp140 (exons 45-50 were assigned to affect only Dp427 and Dp260. Mutations affecting Dp140 and Dp71/Dp40 have been associated with more frequent and more severe cognitive impairment. Finally, the same classification of mutations explained the greater proportion of FSIQ variability associated with cumulative loss of dystrophin isoforms. In conclusion, cumulative loss of dystrophin isoforms increases the risk of intellectual impairment in DMD and characterizing the genotype can define necessity of early cognitive interventions in DMD patients.

  19. Transferability of microsatellite markers located in candidate genes for wood properties between Eucalyptus species

    Directory of Open Access Journals (Sweden)

    Cintia V. Acuña

    2014-12-01

    Full Text Available Aim of study:  To analyze the feasibility of extrapolating conclusions on wood quality genetic control between different Eucalyptus species, particularly from species with better genomic information, to those less characterized. For this purpose, the first step is to analyze the conservation and cross-transferability of microsatellites markers (SSRs located in candidate genes.Area of study: Eucalyptus species implanted in Argentina coming from different Australian origins.Materials and methods: Twelve validated and polymorphic SSRs in candidate genes (SSR-CGs for wood quality in E. globulus were selected for cross species amplification in six species: E. grandis, E. saligna, E. dunnii, E. viminalis, E. camaldulensis and E. tereticornis.Main results: High cross-species transferability (92% to 100% was found for the 12 polymorphic SSRs detected in E. globulus. These markers revealed allelic diversity in nine important candidate genes: cinnamoyl CoA reductase (CCR, cellulose synthase 3 (CesA3, the transcription factor LIM1, homocysteine S-methyltransferase (HMT, shikimate kinase (SK, xyloglucan endotransglycosylase 2 (XTH2, glutathione S-transferase (GST, glutamate decarboxylase (GAD and peroxidase (PER.Research highlights: The markers described are potentially suitable for comparative QTL mapping, molecular marker assisted breeding (MAB and for population genetic studies across different species within the subgenus Symphyomyrtus.Keywords: validation; cross-transferability; SSR; functional markers; eucalypts; Symphyomyrtus.

  20. 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.

  1. Location, location, location

    NARCIS (Netherlands)

    Anderson, S.P.; Goeree, J.K.; Ramer, R.

    1997-01-01

    We analyze the canonical location-then-price duopoly game with general log- concave consumer densities. A unique pure-strategy equilibrium to the two-stage game exists if the density is not "too asymmetric" and not "too concave." These criteria are satisfied by many commonly used densities.

  2. [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.

  3. 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.

  4. Suppressor of cytokine signaling (SOCS genes are silenced by DNA hypermethylation and histone deacetylation and regulate response to radiotherapy in cervical cancer cells.

    Directory of Open Access Journals (Sweden)

    Moon-Hong Kim

    Full Text Available Suppressor of cytokine signaling (SOCS family is an important negative regulator of cytokine signaling and deregulation of SOCS has been involved in many types of cancer. All cervical cancer cell lines tested showed lower expression of SOCS1, SOCS3, and SOCS5 than normal tissue or cell lines. The immunohistochemistry result for SOCS proteins in human cervical tissue also confirmed that normal tissue expressed higher level of SOCS proteins than neighboring tumor. Similar to the regulation of SOCS in other types of cancer, DNA methylation contributed to SOCS1 downregulation in CaSki, ME-180, and HeLa cells. However, the expression of SOCS3 or SOCS5 was not recovered by the inhibition of DNA methylation. Histone deacetylation may be another regulatory mechanism involved in SOCS1 and SOCS3 expression, however, SOCS5 expression was neither affected by DNA methylation nor histone deacetylation. Ectopic expression of SOCS1 or SOCS3 conferred radioresistance to HeLa cells, which implied SOCS signaling regulates the response to radiation in cervical cancer. In this study, we have shown that SOCS expression repressed by, in part, epigenetically and altered SOCS1 and SOCS3 expression could contribute to the radiosensitive phenotype in cervical cancer.

  5. Chromatin structure of ribosomal RNA genes in dipterans and its relationship to the location of nucleolar organizers.

    Science.gov (United States)

    Madalena, Christiane Rodriguez Gutierrez; Díez, José Luís; Gorab, Eduardo

    2012-01-01

    Nucleoli, nuclear organelles in which ribosomal RNA is synthesized and processed, emerge from nucleolar organizers (NORs) located in distinct chromosomal regions. In polytene nuclei of dipterans, nucleoli of some species can be observed under light microscopy exhibiting distinctive morphology: Drosophila and chironomid species display well-formed nucleoli in contrast to the fragmented and dispersed nucleoli seen in sciarid flies. The available data show no apparent relationship between nucleolar morphology and location of NORs in Diptera. The regulation of rRNA transcription involves controlling both the transcription rate per gene as well as the proportion of rRNA genes adopting a proper chromatin structure for transcription, since active and inactive rRNA gene copies coexist in NORs. Transcription units organized in nucleosomes and those lacking canonical nucleosomes can be analyzed by the method termed psoralen gel retarding assay (PGRA), allowing inferences on the ratio of active to inactive rRNA gene copies. In this work, possible connections between chromosomal location of NORs and proportion of active rRNA genes were studied in Drosophila melanogaster, and in chironomid and sciarid species. The data suggested a link between location of NORs and proportion of active rRNA genes since the copy number showing nucleosomal organization predominates when NORs are located in the pericentric heterochromatin. The results presented in this work are in agreement with previous data on the chromatin structure of rRNA genes from distantly related eukaryotes, as assessed by the PGRA.

  6. Chromatin structure of ribosomal RNA genes in dipterans and its relationship to the location of nucleolar organizers.

    Directory of Open Access Journals (Sweden)

    Christiane Rodriguez Gutierrez Madalena

    Full Text Available Nucleoli, nuclear organelles in which ribosomal RNA is synthesized and processed, emerge from nucleolar organizers (NORs located in distinct chromosomal regions. In polytene nuclei of dipterans, nucleoli of some species can be observed under light microscopy exhibiting distinctive morphology: Drosophila and chironomid species display well-formed nucleoli in contrast to the fragmented and dispersed nucleoli seen in sciarid flies. The available data show no apparent relationship between nucleolar morphology and location of NORs in Diptera. The regulation of rRNA transcription involves controlling both the transcription rate per gene as well as the proportion of rRNA genes adopting a proper chromatin structure for transcription, since active and inactive rRNA gene copies coexist in NORs. Transcription units organized in nucleosomes and those lacking canonical nucleosomes can be analyzed by the method termed psoralen gel retarding assay (PGRA, allowing inferences on the ratio of active to inactive rRNA gene copies. In this work, possible connections between chromosomal location of NORs and proportion of active rRNA genes were studied in Drosophila melanogaster, and in chironomid and sciarid species. The data suggested a link between location of NORs and proportion of active rRNA genes since the copy number showing nucleosomal organization predominates when NORs are located in the pericentric heterochromatin. The results presented in this work are in agreement with previous data on the chromatin structure of rRNA genes from distantly related eukaryotes, as assessed by the PGRA.

  7. Construction of an integrated map and location of a bruchid resistance gene in mung bean

    Directory of Open Access Journals (Sweden)

    Lixia Wang

    2016-10-01

    Full Text Available Bruchid beetle (Callosobruchus chinensis poses a serious threat to the production and storage of mung bean (Vigna radiata. Mapping bruchid resistance (Br will provide an important basis for cloning the responsible gene(s and elucidating its functional mechanism, and will also facilitate marker-assisted selection in mung bean breeding. Here, we report the construction of the genetic linkage groups of mung bean and mapping of the Br1 locus using an RIL population derived from a cross between Berken, a bruchid-susceptible line, and ACC41, a bruchid-resistant line. A total of 560 markers were mapped onto 11 linkage groups, with 38.0% of the markers showing distorted segregation. The lengths of the linkage groups ranged from 45.2 to 117.0 cM with a total coverage of 732.9 cM and an average interval of 1.3 cM between loci. Br1 was located on LG9 between BM202 (0.7 cM and Vr2-627 (1.7 cM. Based on 270 shared SSR markers, most of the linkage groups were assigned to specific chromosomes. These results should further accelerate the genetic study of this crop.

  8. 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.

  9. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

    Directory of Open Access Journals (Sweden)

    Sebastian Pita

    2013-05-01

    Full Text Available In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae. The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome or both sex chromosomes (X and Y chromosomes. This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

  10. Medicago truncatula contains a second gene encoding a plastid located glutamine synthetase exclusively expressed in developing seeds

    Directory of Open Access Journals (Sweden)

    Seabra Ana R

    2010-08-01

    Full Text Available Abstract Background Nitrogen is a crucial nutrient that is both essential and rate limiting for plant growth and seed production. Glutamine synthetase (GS, occupies a central position in nitrogen assimilation and recycling, justifying the extensive number of studies that have been dedicated to this enzyme from several plant sources. All plants species studied to date have been reported as containing a single, nuclear gene encoding a plastid located GS isoenzyme per haploid genome. This study reports the existence of a second nuclear gene encoding a plastid located GS in Medicago truncatula. Results This study characterizes a new, second gene encoding a plastid located glutamine synthetase (GS2 in M. truncatula. The gene encodes a functional GS isoenzyme with unique kinetic properties, which is exclusively expressed in developing seeds. Based on molecular data and the assumption of a molecular clock, it is estimated that the gene arose from a duplication event that occurred about 10 My ago, after legume speciation and that duplicated sequences are also present in closely related species of the Vicioide subclade. Expression analysis by RT-PCR and western blot indicate that the gene is exclusively expressed in developing seeds and its expression is related to seed filling, suggesting a specific function of the enzyme associated to legume seed metabolism. Interestingly, the gene was found to be subjected to alternative splicing over the first intron, leading to the formation of two transcripts with similar open reading frames but varying 5' UTR lengths, due to retention of the first intron. To our knowledge, this is the first report of alternative splicing on a plant GS gene. Conclusions This study shows that Medicago truncatula contains an additional GS gene encoding a plastid located isoenzyme, which is functional and exclusively expressed during seed development. Legumes produce protein-rich seeds requiring high amounts of nitrogen, we postulate

  11. Cloning and characterization of a mouse gene with homology to the human von Hippel-Lindau disease tumor suppressor gene: implications for the potential organization of the human von Hippel-Lindau disease gene.

    Science.gov (United States)

    Gao, J; Naglich, J G; Laidlaw, J; Whaley, J M; Seizinger, B R; Kley, N

    1995-02-15

    The human von Hippel-Lindau disease (VHL) gene has recently been identified and, based on the nucleotide sequence of a partial cDNA clone, has been predicted to encode a novel protein with as yet unknown functions [F. Latif et al., Science (Washington DC), 260: 1317-1320, 1993]. The length of the encoded protein and the characteristics of the cellular expressed protein are as yet unclear. Here we report the cloning and characterization of a mouse gene (mVHLh1) that is widely expressed in different mouse tissues and shares high homology with the human VHL gene. It predicts a protein 181 residues long (and/or 162 amino acids, considering a potential alternative start codon), which across a core region of approximately 140 residues displays a high degree of sequence identity (98%) to the predicted human VHL protein. High stringency DNA and RNA hybridization experiments and protein expression analyses indicate that this gene is the most highly VHL-related mouse gene, suggesting that it represents the mouse VHL gene homologue rather than a related gene sharing a conserved functional domain. These findings provide new insights into the potential organization of the VHL gene and nature of its encoded protein.

  12. 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...

  13. 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

  14. 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...

  15. Chromosomal locations of three human nuclear genes (RPSM12, TUFM, and AFG3L1) specifying putative components of the mitochondrial gene expression apparatus.

    Science.gov (United States)

    Shah, Z H; Migliosi, V; Miller, S C; Wang, A; Friedman, T B; Jacobs, H T

    1998-03-15

    We have mapped the chromosomal locations of three human nuclear genes for putative components of the apparatus of mitochondrial gene expression, using a combination of in situ hybridization and interspecies hybrid mapping. The genes RPMS12 (mitoribosomal protein S12, a conserved protein component of the mitoribosomal accuracy center), TUFM (mitochondrial elongation factor EF-Tu), and AFG3L1 (similar to the yeast genes Afg3 and Rca1 involved in the turnover of mistranslated or misfolded mtDNA-encoded polypeptides) were initially characterized by a combination of database sequence analysis, PCR, cloning, and DNA sequencing. RPMS12 maps to chromosome 19q13.1, close to the previously mapped gene for autosomal dominant hearing loss DFNA4. The TUFM gene is located on chromosome 16p11.2, with a putative pseudogene or variant (TUFML) located very close to the centromere of chromosome 17. AFG3L1 is located on chromosome 16q24, very close to the telomere. By virtue of their inferred functions in mitochondria, these genes should be regarded as candidates of disorders sharing features with mitochondrial disease syndromes, such as sensorineural deafness, diabetes, and retinopathy.

  16. 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...

  17. 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

  18. Transcriptional Profiling Identifies Location-Specific and Breed-Specific Differentially Expressed Genes in Embryonic Myogenesis in Anas Platyrhynchos.

    Directory of Open Access Journals (Sweden)

    Rong-Ping Zhang

    Full Text Available Skeletal muscle growth and development are highly orchestrated processes involving significant changes in gene expressions. Differences in the location-specific and breed-specific genes and pathways involved have important implications for meat productions and meat quality. Here, RNA-Seq was performed to identify differences in the muscle deposition between two muscle locations and two duck breeds for functional genomics studies. To achieve those goals, skeletal muscle samples were collected from the leg muscle (LM and the pectoral muscle (PM of two genetically different duck breeds, Heiwu duck (H and Peking duck (P, at embryonic 15 days. Functional genomics studies were performed in two experiments: Experiment 1 directly compared the location-specific genes between PM and LM, and Experiment 2 compared the two breeds (H and P at the same developmental stage (embryonic 15 days. Almost 13 million clean reads were generated using Illumina technology (Novogene, Beijing, China on each library, and more than 70% of the reads mapped to the Peking duck (Anas platyrhynchos genome. A total of 168 genes were differentially expressed between the two locations analyzed in Experiment 1, whereas only 8 genes were differentially expressed when comparing the same location between two breeds in Experiment 2. Gene Ontology (GO and the Kyoto Encyclopedia of Genes and Genomes pathways (KEGG were used to functionally annotate DEGs (differentially expression genes. The DEGs identified in Experiment 1 were mainly involved in focal adhesion, the PI3K-Akt signaling pathway and ECM-receptor interaction pathways (corrected P-value<0.05. In Experiment 2, the DEGs were associated with only the ribosome signaling pathway (corrected P-value<0.05. In addition, quantitative real-time PCR was used to confirm 15 of the differentially expressed genes originally detected by RNA-Seq. A comparative transcript analysis of the leg and pectoral muscles of two duck breeds not only

  19. Differential Splicing of Oncogenes and Tumor Suppressor Genes in African- and Caucasian-American Populations: Contributing Factor in Prostate Cancer Disparities

    Science.gov (United States)

    2015-10-01

    Anatomy and Regen- erativeBiology,TheGeorgeWashingtonUniversitySchoolofMedicine and Health Sciences,Washington, District of Columbia. 7Department of...types of cancers, including prostate, head and neck, renal , lung, breast, colon, ovarian, glioma, pan- creas, and bladder cancers (22, 23). In terms of...triphosphate receptor type 2 (ITPR2) gene as a novel risk locus for renal cell carcinoma (47, 48).MiR-145 has been implicated as a tumor-suppressive miRNA

  20. Inactivation of human α-globin gene expression by a de novo deletion located upstream of the α-globin gene cluster

    International Nuclear Information System (INIS)

    Liebhaber, S.A.; Weiss, I.; Cash, F.E.; Griese, E.U.; Horst, J.; Ayyub, H.; Higgs, D.R.

    1990-01-01

    Synthesis of normal human hemoglobin A, α 2 β 2 , is based upon balanced expression of genes in the α-globin gene cluster on chromosome 15 and the β-globin gene cluster on chromosome 11. Full levels of erythroid-specific activation of the β-globin cluster depend on sequences located at a considerable distance 5' to the β-globin gene, referred to as the locus-activating or dominant control region. The existence of an analogous element(s) upstream of the α-globin cluster has been suggested from observations on naturally occurring deletions and experimental studies. The authors have identified an individual with α-thalassemia in whom structurally normal α-globin genes have been inactivated in cis by a discrete de novo 35-kilobase deletion located ∼30 kilobases 5' from the α-globin gene cluster. They conclude that this deletion inactivates expression of the α-globin genes by removing one or more of the previously identified upstream regulatory sequences that are critical to expression of the α-globin genes

  1. Analysis of aberrant methylation on promoter sequences of tumor suppressor genes and total DNA in sputum samples: a promising tool for early detection of COPD and lung cancer in smokers

    Directory of Open Access Journals (Sweden)

    Guzmán Leda

    2012-07-01

    Full Text Available Abstract Background Chronic obstructive pulmonary disease (COPD is a disorder associated to cigarette smoke and lung cancer (LC. Since epigenetic changes in oncogenes and tumor suppressor genes (TSGs are clearly important in the development of LC. In this study, we hypothesize that tobacco smokers are susceptible for methylation in the promoter region of TSGs in airway epithelial cells when compared with non-smoker subjects. The purpose of this study was to investigate the usefulness of detection of genes promoter methylation in sputum specimens, as a complementary tool to identify LC biomarkers among smokers with early COPD. Methods We determined the amount of DNA in induced sputum from patients with COPD (n = 23, LC (n = 26, as well as in healthy subjects (CTR (n = 33, using a commercial kit for DNA purification, followed by absorbance measurement at 260 nm. The frequency of CDKN2A, CDH1 and MGMT promoter methylation in the same groups was determined by methylation-specific polymerase chain reaction (MSP. The Fisher’s exact test was employed to compare frequency of results between different groups. Results DNA concentration was 7.4 and 5.8 times higher in LC and COPD compared to the (CTR (p  Conclusions We provide evidence that aberrant methylation of TSGs in samples of induced sputum is a useful tool for early diagnostic of lung diseases (LC and COPD in smoker subjects. Virtual slides The abstract MUST finish with the following text: Virtual Slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1127865005664160

  2. Von Hippel-Lindau tumor suppressor gene loss in renal cell carcinoma promotes oncogenic epidermal growth factor receptor signaling via Akt-1 and MEK-1.

    Science.gov (United States)

    Lee, S Justin; Lattouf, Jean-Baptiste; Xanthopoulos, Julie; Linehan, W Marston; Bottaro, Donald P; Vasselli, James R

    2008-10-01

    Clear-cell renal cell carcinoma (RCC) is the most prevalent form of kidney cancer and is frequently associated with loss of von Hippel-Lindau (VHL) gene function, resulting in the aberrant transcriptional activation of genes that contribute to tumor growth and metastasis, including transforming growth factor-alpha (TGF-alpha), a ligand of the epidermal growth factor receptor (EGFR) tyrosine kinase. To determine the functional impact of EGFR activation on RCC, we suppressed critical components of this pathway: EGFR, Akt-1, and MEK-1. Stable transfection of RCC cells with plasmids bearing shRNA directed against each of these genes was used to individually suppress their expression. Transfectants were characterized for growth and invasiveness in vitro and tumorigenesis in vivo. RCC cell transfectants displayed significantly reduced growth rate and matrix invasion in vitro and RCC tumor xenograft growth rate in vivo. Analysis of tumor cells that emerged after extended periods in each model showed that significant EGFR suppression was sustained, whereas Akt-1 and MEK-1 knock-down cells had escaped shRNA suppression. EGFR, Akt-1, and MEK-1 are individually critical for RCC cell invasiveness in vitro and tumorigenicity in vivo, and even partial suppression of each can have a significant impact on tumor progression. The emergence of transfectants that had escaped Akt-1 and MEK-1 suppression during tumorigenicity experiments suggests that these effectors may each be more critical than EGFR for RCC tumorigenesis, consistent with results from clinical trials of EGFR inhibitors for RCC, where durable clinical responses have not been seen.

  3. Von Hippel-Lindau Tumor Suppressor Gene Loss in Renal Cell Carcinoma Promotes Oncogenic Epidermal Growth Factor Receptor Signaling via Akt-1 and MEK1

    Science.gov (United States)

    Lee, S. Justin; Lattouf, Jean-Baptiste; Xanthopoulos, Julie; Linehan, W. Marston; Bottaro, Donald P.; Vasselli, James R.

    2008-01-01

    Objectives Clear-cell renal cell carcinoma (RCC) is the most prevalent form of kidney cancer and is frequently associated with loss of von Hippel-Lindau (VHL) gene function, resulting in the aberrant transcriptional activation of genes that contribute to tumor growth and metastasis, including transforming growth factor-α (TGF-α), a ligand of the epidermal growth factor receptor (EGFR) tyrosine kinase. To determine the functional impact of EGFR activation on RCC, we suppressed critical components of this pathway: EGFR, Akt-1, and MEK-1. Methods Stable transfection of RCC cells with plasmids bearing shRNA directed against each of these genes was used to individually suppress their expression. Transfectants were characterized for growth and invasiveness in vitro and tumorigenesis in vivo. Results RCC cell transfectants displayed significantly reduced growth rate and matrix invasion in vitro and RCC tumor xenograft growth rate in vivo. Analysis of tumor cells that emerged after extended periods in each model showed that significant EGFR suppression was sustained, whereas Akt-1 and MEK-1 knockdown cells had escaped shRNA suppression. Conclusions EGFR, Akt-1, and MEK-1 are individually critical for RCC cell invasiveness in vitro and tumorigenicity in vivo, and even partial suppression of each can have a significant impact on tumor progression. The emergence of transfectants that had escaped Akt-1 and MEK-1 suppression during tumorigenicity experiments suggests that these effectors may each be more critical than EGFR for RCC tumorigenesis, consistent with results from clinical trials of EGFR inhibitors for RCC, where durable clinical responses have not been seen. PMID:18243508

  4. Extravirgin olive oil up-regulates CB₁ tumor suppressor gene in human colon cancer cells and in rat colon via epigenetic mechanisms.

    Science.gov (United States)

    Di Francesco, Andrea; Falconi, Anastasia; Di Germanio, Clara; Micioni Di Bonaventura, Maria Vittoria; Costa, Antonio; Caramuta, Stefano; Del Carlo, Michele; Compagnone, Dario; Dainese, Enrico; Cifani, Carlo; Maccarrone, Mauro; D'Addario, Claudio

    2015-03-01

    Extravirgin olive oil (EVOO) represents the typical lipid source of the Mediterranean diet, an eating habit pattern that has been associated with a significant reduction of cancer risk. Diet is the more studied environmental factor in epigenetics, and many evidences suggest dysregulation of epigenetic pathways in cancer. The aim of our study was to investigate the effects of EVOO and its phenolic compounds on endocannabinoid system (ECS) gene expression via epigenetic regulation in both human colon cancer cells (Caco-2) and rats exposed to short- and long-term dietary EVOO. We observed a selective and transient up-regulation of CNR1 gene - encoding for type 1 cannabinoid receptor (CB₁) - that was evoked by exposure of Caco-2 cells to EVOO (100 ppm), its phenolic extracts (OPE, 50 μM) or authentic hydroxytyrosol (HT, 50 μM) for 24 h. None of the other major elements of the ECS (i.e., CB₂; GPR55 and TRPV1 receptors; and NAPE-PLD, DAGL, FAAH and MAGL enzymes) was affected at any time point. The stimulatory effect of OPE and HT on CB₁ expression was inversely correlated to DNA methylation at CNR1 promoter and was associated with reduced proliferation of Caco-2 cells. Interestingly, CNR1 gene was less expressed in Caco-2 cells when compared to normal colon mucosa cells, and again this effect was associated with higher level of DNA methylation at CNR1. Moreover, in agreement with the in vitro studies, we also observed a remarkable (~4-fold) and selective increase in CB₁ expression in the colon of rats receiving dietary EVOO supplementation for 10 days. Consistently, CpG methylation of rat Cnr1 promoter, miR23a and miR-301a, previously shown to be involved in the pathogenesis of colorectal cancer and predicted to target CB₁ mRNA, was reduced after EVOO administration down to ~50% of controls. Taken together, our findings demonstrating CB₁ gene expression modulation by EVOO or its phenolic compounds via epigenetic mechanism, both in vitro and in vivo, may

  5. MicroRNA-429 induces tumorigenesis of human non-small cell lung cancer cells and targets multiple tumor suppressor genes

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Yaoguo; Xu, Shidong; Ma, Jianqun; Wu, Jun [Department of Thoracic Surgery, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, Heilongjiang 150081 (China); Jin, Shi; Cao, Shoubo [Department of Medical Oncology, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, Heilongjiang 150081 (China); Yu, Yan, E-mail: yuyan@hrbmu.edu.cn [Department of Medical Oncology, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, Heilongjiang 150081 (China)

    2014-07-18

    Highlights: • MiR-429 expression is upregulated in non-small cell lung cancer (NSCLC). • MiR-429 inhibits PTEN, RASSF8 and TIMP2 expression. • MiR-429 promotes metastasis and proliferation. • We report important regulatory mechanisms involved in NSCLC progression. • MiR-429 is a potential therapeutic target and diagnostic marker. - Abstract: Lung cancer is the major cause of cancer death globally. MicroRNAs are evolutionally conserved small noncoding RNAs that are critical for the regulation of gene expression. Aberrant expression of microRNA (miRNA) has been implicated in cancer initiation and progression. In this study, we demonstrated that the expression of miR-429 are often upregulated in non-small cell lung cancer (NSCLC) compared with normal lung tissues, and its expression level is also increased in NSCLC cell lines compared with normal lung cells. Overexpression of miR-429 in A549 NSCLC cells significantly promoted cell proliferation, migration and invasion, whereas inhibition of miR-429 inhibits these effects. Furthermore, we demonstrated that miR-429 down-regulates PTEN, RASSF8 and TIMP2 expression by directly targeting the 3′-untranslated region of these target genes. Taken together, our results suggest that miR-429 plays an important role in promoting the proliferation and metastasis of NSCLC cells and is a potential target for NSCLC therapy.

  6. 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

  7. Variation in sequence and location of the fumonisin mycotoxin niosynthetic gene cluster in Fusarium

    NARCIS (Netherlands)

    Proctor, R.H.; Hove, van F.; Susca, A.; Stea, A.; Busman, M.; Lee, van der T.A.J.; Waalwijk, C.; Moretti, A.

    2010-01-01

    In Fusarium, the ability to produce fumonisins is governed by a 17-gene fumonisin biosynthetic gene (FUM) cluster. Here, we examined the cluster in F. oxysporum strain O-1890 and nine other species selected to represent a wide range of the genetic diversity within the GFSC.

  8. Genetic analysis and location of gene for resistance to stripe rust in ...

    Indian Academy of Sciences (India)

    2013-08-06

    Aug 6, 2013 ... Institute of Plant Protection, Chinese Academy of Agriculture Science, No 2, West ... The molecular marker Xbarc59 closely linked to the gene YrSD could be ... and a minor resistance gene postulated in it (Calonnec et al.

  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. 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...

  11. 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...

  12. Tet1 Oxidase Regulates Neuronal Gene Transcription, Active DNA Hydroxy-methylation, Object Location Memory, and Threat Recognition Memory.

    Science.gov (United States)

    Kumar, Dinesh; Aggarwal, Milan; Kaas, Garrett A; Lewis, John; Wang, Jing; Ross, Daniel L; Zhong, Chun; Kennedy, Andrew; Song, Hongjun; Sweatt, J David

    2015-10-01

    A dynamic equilibrium between DNA methylation and demethylation of neuronal activity-regulated genes is crucial for memory processes. However, the mechanisms underlying this equilibrium remain elusive. Tet1 oxidase has been shown to play a key role in the active DNA demethylation in the CNS. In this study, we used Tet1 gene knockout (Tet1KO) mice to examine the involvement of Tet1 in memory consolidation and storage in the adult brain. We found that Tet1 ablation leads to: altered expression of numerous neuronal activity-regulated genes, compensatory upregulation of active demethylation pathway genes, and upregulation of various epigenetic modifiers. Moreover, Tet1KO mice showed an enhancement in the consolidation and storage of threat recognition (cued and contextual fear conditioning) and object location memories. We conclude that Tet1 plays a critical role in regulating neuronal transcription and in maintaining the epigenetic state of the brain associated with memory consolidation and storage.

  13. A novel human gene encoding a G-protein-coupled receptor (GPR15) is located on chromosome 3

    Energy Technology Data Exchange (ETDEWEB)

    Heiber, M.; Marchese, A.; O`Dowd, B.F. [Univ. of Toronto, Ontario (Canada)] [and others

    1996-03-05

    We used sequence similarities among G-protein-coupled receptor genes to discover a novel receptor gene. Using primers based on conserved regions of the opioid-related receptors, we isolated a PCR product that was used to locate the full-length coding region of a novel human receptor gene, which we have named GPR15. A comparison of the amino acid sequence of the receptor gene, which we have named GPR15. A comparison of the amino acid sequence of the receptor encoded by GPR15 with other receptors revealed that it shared sequence identity with the angiotensin II AT1 and AT2 receptors, the interleukin 8b receptor, and the orphan receptors GPR1 and AGTL1. GPR15 was mapped to human chromosome 3q11.2-q13.1. 12 refs., 2 figs.

  14. Tet1 oxidase regulates neuronal gene transcription, active DNA hydroxymethylation, object location memory, and threat recognition memory

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2015-10-01

    Full Text Available A dynamic equilibrium between DNA methylation and demethylation of neuronal activity-regulated genes is crucial for memory processes. However, the mechanisms underlying this equilibrium remain elusive. Tet1 oxidase has been shown to play a key role in the active DNA demethylation in the central nervous system. In this study, we used Tet1 gene knockout (Tet1KO mice to examine the involvement of Tet1 in memory consolidation and storage in the adult brain. We found that Tet1 ablation leads to altered expression of numerous neuronal activity-regulated genes, compensatory upregulation of active demethylation pathway genes, and upregulation of various epigenetic modifiers. Moreover, Tet1KO mice showed an enhancement in the consolidation and storage of threat recognition (cued and contextual fear conditioning and object location memories. We conclude that Tet1 plays a critical role in regulating neuronal transcription and in maintaining the epigenetic state of the brain associated with memory consolidation and storage.

  15. Fine Mapping of Two Wheat Powdery Mildew Resistance Genes Located at the Pm1 Cluster

    Directory of Open Access Journals (Sweden)

    Junchao Liang

    2016-07-01

    Full Text Available Powdery mildew caused by (DC. f. sp. ( is a globally devastating foliar disease of wheat ( L.. More than a dozen genes against this disease, identified from wheat germplasms of different ploidy levels, have been mapped to the region surrounding the locus on the long arm of chromosome 7A, which forms a resistance (-gene cluster. and from einkorn wheat ( L. were two of the genes belonging to this cluster. This study was initiated to fine map these two genes toward map-based cloning. Comparative genomics study showed that macrocolinearity exists between L. chromosome 1 (Bd1 and the – region, which allowed us to develop markers based on the wheat sequences orthologous to genes contained in the Bd1 region. With these and other newly developed and published markers, high-resolution maps were constructed for both and using large F populations. Moreover, a physical map of was constructed through chromosome walking with bacterial artificial chromosome (BAC clones and comparative mapping. Eventually, and were restricted to a 0.12- and 0.86-cM interval, respectively. Based on the closely linked common markers, , , and (another powdery mildew resistance gene in the cluster were not allelic to one another. Severe recombination suppression and disruption of synteny were noted in the region encompassing . These results provided useful information for map-based cloning of the genes in the cluster and interpretation of their evolution.

  16. The tumor suppressor homolog in fission yeast, myh1{sup +}, displays a strong interaction with the checkpoint gene rad1{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Kristina; Warringer, Jonas; Farewell, Anne [Department of Cell and Molecular Biology, Lundberg Laboratory, Goeteborg University, P.O. Box 462, Goeteborg SE-405 30 (Sweden); Park, Han-Oh [Bioneer Corporation, 49-3, Munpyeong-dong, Daedeok-gu, Daejon 306-220 (Korea, Republic of); Hoe, Kwang-Lae; Kim, Dong-Uk [Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yusong, Daejeon (Korea, Republic of); Hayles, Jacqueline [Cell Cycle Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln' s Inn Fields, London WC2A 3PX (United Kingdom); Sunnerhagen, Per [Department of Cell and Molecular Biology, Lundberg Laboratory, Goeteborg University, P.O. Box 462, Goeteborg SE-405 30 (Sweden)], E-mail: per.sunnerhagen@cmb.gu.se

    2008-09-26

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1{sup +}, we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway.

  17. Orphan nuclear receptor TLX functions as a potent suppressor of oncogene-induced senescence in prostate cancer via its transcriptional co-regulation of the CDKN1A (p21(WAF1) (/) (CIP1) ) and SIRT1 genes.

    Science.gov (United States)

    Wu, Dinglan; Yu, Shan; Jia, Lin; Zou, Chang; Xu, Zhenyu; Xiao, Lijia; Wong, Kam-Bo; Ng, Chi-Fai; Chan, Franky L

    2015-05-01

    Oncogene-induced senescence is an important tumour-suppressing mechanism to prevent both premalignant transformation and cancer progression. Overcoming this process is a critical step in early cancer development. The druggable orphan nuclear receptor TLX (NR2E1) is characterized as an important regulator of neural stem cells and is also implicated in the development of some brain tumours. However, its exact functional roles in cancer growth regulation still remain unclear. Here we report that TLX can act as a promoter of tumourigenesis in prostate cancer by suppressing oncogene-induced senescence. We determined that TLX exhibited an increased expression in high-grade prostate cancer tissues and many prostate cancer cell lines. Functional studies revealed that TLX could perform an oncogenic function in prostate cancer cells, as its knockdown triggered cellular senescence and cell growth arrest in vitro and in vivo, whereas its over-expression promoted the malignant growth of prostate cancer cells. Furthermore, enhancement of TLX activity, by either ectopic expression or ligand stimulation, could potently prevent doxorubicin-induced senescence in prostate cancer cells and also allow prostatic epithelial cells to escape oncogene-induced senescence induced either by activated oncogene H-Ras(G12V) or knockdown of tumour suppressor PTEN, via a mechanism of direct but differential transcriptional regulation of two senescence-associated genes, repression of CDKN1A and transactivation of SIRT1. Together, our present study shows, for the first time, that TLX may play an important role in prostate carcinogenesis through its suppression of oncogene-induced senescence, and also suggests that targeting the senescence-regulatory TLX is of potential therapeutic significance in prostate cancer. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  18. Sequence Variation in Toxoplasma gondii rop17 Gene among Strains from Different Hosts and Geographical Locations

    Directory of Open Access Journals (Sweden)

    Nian-Zhang Zhang

    2014-01-01

    Full Text Available Genetic diversity of T. gondii is a concern of many studies, due to the biological and epidemiological diversity of this parasite. The present study examined sequence variation in rhoptry protein 17 (ROP17 gene among T. gondii isolates from different hosts and geographical regions. The rop17 gene was amplified and sequenced from 10 T. gondii strains, and phylogenetic relationship among these T. gondii strains was reconstructed using maximum parsimony (MP, neighbor-joining (NJ, and maximum likelihood (ML analyses. The partial rop17 gene sequences were 1375 bp in length and A+T contents varied from 49.45% to 50.11% among all examined T. gondii strains. Sequence analysis identified 33 variable nucleotide positions (2.1%, 16 of which were identified as transitions. Phylogeny reconstruction based on rop17 gene data revealed two major clusters which could readily distinguish Type I and Type II strains. Analyses of sequence variations in nucleotides and amino acids among these strains revealed high ratio of nonsynonymous to synonymous polymorphisms (>1, indicating that rop17 shows signs of positive selection. This study demonstrated the existence of slightly high sequence variability in the rop17 gene sequences among T. gondii strains from different hosts and geographical regions, suggesting that rop17 gene may represent a new genetic marker for population genetic studies of T. gondii isolates.

  19. In Search of 'Birth Month Genes': Using Existing Data Repositories to Locate Genes Underlying Birth Month-Disease Relationships.

    Science.gov (United States)

    Boland, Mary Regina; Tatonetti, Nicholas P

    2016-01-01

    Prenatal and perinatal exposures vary seasonally (e.g., sunlight, allergens) and many diseases are linked with variance in exposure. Epidemiologists often measure these changes using birth month as a proxy for seasonal variance. Likewise, Genome-Wide Association Studies have associated or implicated these same diseases with many genes. Both disparate data types (epidemiological and genetic) can provide key insights into the underlying disease biology. We developed an algorithm that links 1) epidemiological data from birth month studies with 2) genetic data from published gene-disease association studies. Our framework uses existing data repositories - PubMed, DisGeNET and Gene Ontology - to produce a bipartite network that connects enriched seasonally varying biofactorss with birth month dependent diseases (BMDDs) through their overlapping developmental gene sets. As a proof-of-concept, we investigate 7 known BMDDs and highlight three important biological networks revealed by our algorithm and explore some interesting genetic mechanisms potentially responsible for the seasonal contribution to BMDDs.

  20. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in 'Thatcher' Wheat.

    Science.gov (United States)

    Hiebert, Colin W; Kolmer, James A; McCartney, Curt A; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34.

  1. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in ‘Thatcher’ Wheat

    Science.gov (United States)

    Hiebert, Colin W.; Kolmer, James A.; McCartney, Curt A.; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N.; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. ‘Thatcher’ wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in ‘Thatcher’ and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for ‘Thatcher’-derived APR in several environments and this resistance was enhanced in the presence of Lr34. PMID:27309724

  2. Regulation of apoptosis by low serum in cells of different stages of neoplastic progression: enhanced susceptibility after loss of a senescence gene and decreased susceptibility after loss of a tumor suppressor gene.

    Science.gov (United States)

    Preston, G A; Lang, J E; Maronpot, R R; Barrett, J C

    1994-08-01

    A cell culture model system has been used to study the susceptibility of cells to apoptotic cell death during different stages of neoplastic progression. This system consists of normal diploid Syrian hamster embryo (SHE) cells, two preneoplastic cell lines [tumor suppressor stage I (sup +I) and non-tumor suppressor stage II (sup -II)], and hamster tumor cell lines. Stage I preneoplastic cells are nontumorigenic immortal clones that suppress tumorigenicity when hybridized to tumor cells, whereas stage II cells have lost the ability to suppress tumorigenicity in cell hybrids. We refer to these two types of preneoplastic cells as sup +I and sup -II, respectively. Neoplastic progression is generally associated with cellular alterations in growth factor responsiveness. Therefore, to study the regulation of apoptosis in the system described above, cells were cultured in low serum (0.2%) as a means of withdrawing growth factors. In low serum, normal SHE cells were quiescent (labeling index of 0.2%), with little cell death. The sup +I cells showed a relatively low labeling index (1.6%) but, in contrast to the normal cells, died at a high rate (55% cell loss after 48 h) by apoptosis, as evidenced by morphology, DNA fragmentation, and in situ end-labeling of fragmented DNA. The apoptotic cells did not go through a replicative cycle while in low serum, implying that apoptosis was initiated in the G0/G1 phase of the cell cycle. The sup -II cell line showed a high labeling index (40%) after 48 h, but cell growth was balanced by cell death that occurred at approximately the same rate. The cells died, however, predominantly by necrosis. The tumor cell lines continued to proliferate in low serum, with high labeling indices (ranging from 27% to 43%) and a low level of apoptotic or necrotic cell death. To determine the relative ability of these cells to survive in vivo, normal SHE cells, sup +I cells, and sup -II cells were injected s.c. into nude mice. At 5 or 21 days after

  3. The gene for the Ellis-van Creveld syndrome is located on chromosome 4p16

    Energy Technology Data Exchange (ETDEWEB)

    Polymeropoulos, M.H.; Ide, S.E. [National Institute of Health, Bethesda, MD (United States); Wright, M. [Univ. of Newcastle Upon Tyne (United Kingdom)] [and others

    1996-07-01

    Ellis-van Creveld syndrome (EVC) is an autosomal recessive disorder characterized by disproportionate dwarfism, polydactyly, and congenital heart disease. This rare disorder is found with increased frequency among the Old Order Amish community in Lancaster County, Pennsylvania. We have used linkage analysis to localize the gene responsible for the EVC phenotype in nine interrelated Amish pedigrees and three unrelated families from Mexico, Ecuador, and Brazil. We now report the linkage for the Ellisvan Creveld syndrome gene to markers on the distal short arm of human chromosome 4, with Z{sub max} = 6.91 at {theta} = 0.02 for marker HOX7, in a region proximal to the FGFR3 gene responsible for the achondroplasia phenotype. 17 refs., 2 figs., 1 tab.

  4. The Y-located gonadoblastoma gene TSPY amplifies its own expression through a positive feedback loop in prostate cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kido, Tatsuo; Lau, Yun-Fai Chris, E-mail: Chris.Lau@UCSF.edu

    2014-03-28

    Highlights: • Y-encoded proto-oncoprotein TSPY amplifies its expression level via a positive feedback loop. • TSPY binds to the chromatin/DNA at exon 1 of TSPY gene. • TSPY enhances the gene expression in a TSPY exon 1 sequence dependent manner. • The conserved SET/NAP-domain is essential for TSPY transactivation. • Insights on probable mechanisms on TSPY exacerbation on cancer development in men. - Abstract: The testis-specific protein Y-encoded (TSPY) is a repetitive gene located on the gonadoblastoma region of the Y chromosome, and has been considered to be the putative gene for this oncogenic locus on the male-only chromosome. It is expressed in spermatogonial cells and spermatocytes in normal human testis, but abundantly in gonadoblastoma, testicular germ cell tumors and a variety of somatic cancers, including melanoma, hepatocellular carcinoma and prostate cancer. Various studies suggest that TSPY accelerates cell proliferation and growth, and promotes tumorigenesis. In this report, we show that TSPY could bind directly to the chromatin/DNA at exon 1 of its own gene, and greatly enhance the transcriptional activities of the endogenous gene in the LNCaP prostate cancer cells. Domain mapping analyses of TSPY have localized the critical and sufficient domain to the SET/NAP-domain. These results suggest that TSPY could efficiently amplify its expression and oncogenic functions through a positive feedback loop, and contribute to the overall tumorigenic processes when it is expressed in various human cancers.

  5. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations.

    Science.gov (United States)

    Zhao, Yu; Zhou, Donghui; Chen, Jia; Sun, Xiaolin

    2017-01-01

    Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs) play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis. The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10) gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR) amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI) and maximum parsimony (MP). Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes. TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  6. Analysis of aneuploid lines of bread wheat to map chromosomal locations of genes controlling root hair length.

    Science.gov (United States)

    Liu, Miao; Rathjen, Tina; Weligama, Kumara; Forrest, Kerrie; Hayden, Matthew; Delhaize, Emmanuel

    2017-06-01

    Long root hairs enable the efficient uptake of poorly mobile nutrients such as phosphorus. Mapping the chromosomal locations of genes that control root hair length can help exploit the natural variation within crops to develop improved cultivars. Genetic stocks of the wheat cultivar 'Chinese Spring' were used to map genes that control root hair length. Aneuploid stocks of 'Chinese Spring' were screened using a rapid method based on rhizosheath size and then selected lines were assayed for root hair length to identify chromosomes harbouring genes controlling root hair length. A series of lines with various fractional deletions of candidate chromosomes were then screened to map the root hair loci more accurately. A line with a deletion in chromosome 5A was analysed with a 90 000 single nucleotide polymorphism (SNP) array. The phosphorus acquisition efficiency (PAE) of one deletion line was compared with that of euploid 'Chinese Spring' by growing the seedlings in pots at low and luxury phosphorus supplies. Chromosomes 1A, 1D and 5A were found to harbour genes controlling root hair length. The 90 000 SNP array identified two candidate genes controlling root hair length located on chromosome 5A. The line with a deletion in chromosome 5A had root hairs that were approx. 20 % shorter than euploid 'Chinese Spring', but this was insufficient to reduce its PAE. A rapid screen for rhizosheath size enabled chromosomal regions controlling root hair length to be mapped in the wheat cultivar 'Chinese Spring' and subsequent analysis with an SNP array identified candidate genes controlling root hair length. The difference in root hair length between euploid 'Chinese Spring' and a deletion line identified in the rapid screen was still apparent, albeit attenuated, when the seedlings were grown on a fully fertilized soil. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  7. Lipase genes in Mucor circinelloides: identification, sub-cellular location, phylogenetic analysis and expression profiling during growth and lipid accumulation.

    Science.gov (United States)

    Zan, Xinyi; Tang, Xin; Chu, Linfang; Zhao, Lina; Chen, Haiqin; Chen, Yong Q; Chen, Wei; Song, Yuanda

    2016-10-01

    Lipases or triacylglycerol hydrolases are widely spread in nature and are particularly common in the microbial world. The filamentous fungus Mucor circinelloides is a potential lipase producer, as it grows well in triacylglycerol-contained culture media. So far only one lipase from M. circinelloides has been characterized, while the majority of lipases remain unknown in this fungus. In the present study, 47 potential lipase genes in M. circinelloides WJ11 and 30 potential lipase genes in M. circinelloides CBS 277.49 were identified by extensive bioinformatics analysis. An overview of these lipases is presented, including several characteristics, sub-cellular location, phylogenetic analysis and expression profiling of the lipase genes during growth and lipid accumulation. All of these proteins contained the consensus sequence for a classical lipase (GXSXG motif) and were divided into four types including α/β-hydrolase_1, α/β-hydrolase_3, class_3 and GDSL lipase (GDSL) based on gene annotations. Phylogenetic analyses revealed that class_3 family and α/β-hydrolase_3 family were the conserved lipase family in M. circinelloides. Additionally, some lipases also contained a typical acyltransferase motif of H-(X) 4-D, and these lipases may play a dual role in lipid metabolism, catalyzing both lipid hydrolysis and transacylation reactions. The differential expression of all lipase genes were confirmed by quantitative real-time PCR, and the expression profiling were analyzed to predict the possible biological roles of these lipase genes in lipid metabolism in M. circinelloides. We preliminarily hypothesized that lipases may be involved in triacylglycerol degradation, phospholipid synthesis and beta-oxidation. Moreover, the results of sub-cellular localization, the presence of signal peptide and transcriptional analyses of lipase genes indicated that four lipase in WJ11 most likely belong to extracellular lipases with a signal peptide. These findings provide a platform

  8. Location of a High-Lysine Gene and the DDT-Resistance Gene on Barley Chromosome 7

    DEFF Research Database (Denmark)

    Jensen, J.

    1979-01-01

    mutants, nos 1508.18, and 19. Linkage studies with translocations locate the Lys3 locus in the centromere region ofchromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker locifi (fragile stem), s(short rachilla hairs), and r (smooth awn) show...... that the order of the five loci on chromosome 7 from the long to the short chromosome arm is Y, s,fi, lys3, ddt. The distance from locus I to locus ddt is about 100 centimorgans....

  9. Locating disease genes using Bayesian variable selection with the Haseman-Elston method

    Directory of Open Access Journals (Sweden)

    He Qimei

    2003-12-01

    Full Text Available Abstract Background We applied stochastic search variable selection (SSVS, a Bayesian model selection method, to the simulated data of Genetic Analysis Workshop 13. We used SSVS with the revisited Haseman-Elston method to find the markers linked to the loci determining change in cholesterol over time. To study gene-gene interaction (epistasis and gene-environment interaction, we adopted prior structures, which incorporate the relationship among the predictors. This allows SSVS to search in the model space more efficiently and avoid the less likely models. Results In applying SSVS, instead of looking at the posterior distribution of each of the candidate models, which is sensitive to the setting of the prior, we ranked the candidate variables (markers according to their marginal posterior probability, which was shown to be more robust to the prior. Compared with traditional methods that consider one marker at a time, our method considers all markers simultaneously and obtains more favorable results. Conclusions We showed that SSVS is a powerful method for identifying linked markers using the Haseman-Elston method, even for weak effects. SSVS is very effective because it does a smart search over the entire model space.

  10. Intellectual disability, oncogenes and tumour suppressor genes

    Indian Academy of Sciences (India)

    M. Bidart1 2 3 C. Coutton4 5 3. Plateforme Protéomique et Transcriptomique Clinique, Pole Recherche, CHU Grenoble, 38043 Grenoble, France; Equipe, Nanomédecine et Cerveau, Inserm U836, Grenoble Institut Neurosciences, 38000 Grenoble, France; Université Joseph Fourier, 38000 Grenoble, France; Département ...

  11. Orthologous microRNA genes are located in cancer-associated genomic regions in human and mouse.

    Directory of Open Access Journals (Sweden)

    Igor V Makunin

    Full Text Available BACKGROUND: MicroRNAs (miRNAs are short non-coding RNAs that regulate differentiation and development in many organisms and play an important role in cancer. METHODOLOGY/PRINCIPAL FINDINGS: Using a public database of mapped retroviral insertion sites from various mouse models of cancer we demonstrate that MLV-derived retroviral inserts are enriched in close proximity to mouse miRNA loci. Clustered inserts from cancer-associated regions (Common Integration Sites, CIS have a higher association with miRNAs than non-clustered inserts. Ten CIS-associated miRNA loci containing 22 miRNAs are located within 10 kb of known CIS insertions. Only one CIS-associated miRNA locus overlaps a RefSeq protein-coding gene and six loci are located more than 10 kb from any RefSeq gene. CIS-associated miRNAs on average are more conserved in vertebrates than miRNAs associated with non-CIS inserts and their human homologs are also located in regions perturbed in cancer. In addition we show that miRNA genes are enriched around promoter and/or terminator regions of RefSeq genes in both mouse and human. CONCLUSIONS/SIGNIFICANCE: We provide a list of ten miRNA loci potentially involved in the development of blood cancer or brain tumors. There is independent experimental support from other studies for the involvement of miRNAs from at least three CIS-associated miRNA loci in cancer development.

  12. Response of microbial community and catabolic genes to simulated petroleum hydrocarbon spills in soils/sediments from different geographic locations.

    Science.gov (United States)

    Liu, Q; Tang, J; Liu, X; Song, B; Zhen, M; Ashbolt, N J

    2017-10-01

    Study the response of microbial communities and selected petroleum hydrocarbon (PH)-degrading genes on simulated PH spills in soils/sediments from different geographic locations. A microcosm experiment was conducted by spiking mixtures of petroleum hydrocarbons (PHs) to soils/sediments collected from four different regions of China, including the Dagang Oilfield (DG), Sand of Bohai Sea (SS), Northeast China (NE) and Xiamen (XM). Changes in bacterial community and the abundance of PH-degrading genes (alkB, nah and phe) were analysed by denaturing gradient electrophoresis (DGGE) and qPCR, respectively. Degradation of alkanes and PAHs in SS and NE materials were greater (P < 0·05) than those in DG and XM. Clay content was negatively correlated with the degradation of total alkanes by 112 days and PAHs by 56 days, while total organic carbon content was negatively correlated with initial degradation of total alkanes as well as PAHs. Abundances of alkB, nah and phe genes increased 10- to 100-fold and varied by soil type over the incubation period. DGGE fingerprints identified the dominance of α-, β- and γ-Proteobacteria (Gram -ve) and Actinobacteria (Gram +ve) bacteria associated with degradation of PHs in the materials studied. The geographic divergence resulting from the heterogeneity of physicochemical properties of soils/sediments appeared to influence the abundance of metabolic genes and community structure of microbes capable of degrading PHs. When developing practical in-situ bioremediation approaches for PHs contamination of soils/sediment, appropriate microbial community structures and the abundance of PH-degrading genes appear to be influenced by geographic location. © 2017 The Society for Applied Microbiology.

  13. Annotation of differentially expressed genes in the somatic embryogenesis of musa and their location in the banana genome.

    Science.gov (United States)

    Maldonado-Borges, Josefina Ines; Ku-Cauich, José Roberto; Escobedo-Graciamedrano, Rosa Maria

    2013-01-01

    Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100-4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somatic embryogenesis of Musa.

  14. 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...

  15. Location-specific epigenetic regulation of the metallothionein 3 gene in esophageal adenocarcinomas.

    Directory of Open Access Journals (Sweden)

    Dunfa Peng

    Full Text Available Metallothionein 3 (MT3 maintains intracellular metal homeostasis and protects against reactive oxygen species (ROS-induced DNA damage. In this study, we investigated the epigenetic alterations and gene expression of the MT3 gene in esophageal adenocarcinomas (EACs.Using quantitative bisulfite pyrosequencing, we detected unique DNA methylation profiles in the MT3 promoter region. The CpG nucleotides from -372 to -306 from the transcription start site (TSS were highly methylated in tumor (n = 64 and normal samples (n = 51, whereas CpG nucleotides closest to the TSS (-4 and +3 remained unmethylated in all normal and most tumor samples. Conversely, CpG nucleotides in two regions (from -139 to -49 and +296 to +344 were significantly hypermethylated in EACs as compared to normal samples [FDR3.0]. The DNA methylation levels from -127 to -8 CpG sites showed the strongest correlation with MT3 gene expression (r = -0.4, P<0.0001. Moreover, the DNA hypermethylation from -127 to -8 CpG sites significantly correlated with advanced tumor stages and lymph node metastasis (P = 0.005 and P = 0.0313, respectively. The ChIP analysis demonstrated a more repressive histone modification (H3K9me2 and less active histone modifications (H3K4me2, H3K9ace in OE33 cells than in FLO-1 cells; concordant with the presence of higher DNA methylation levels and silencing of MT3 expression in OE33 as compared to FLO-1 cells. Treatment of OE33 cells with 5-Aza-deoxycitidine restored MT3 expression with demethylation of its promoter region and reversal of the histone modifications towards active histone marks.In summary, EACs are characterized by frequent epigenetic silencing of MT3. The choice of specific regions in the CpG island is a critical step in determining the functional role and prognostic value of DNA methylation in cancer cells.

  16. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations

    Directory of Open Access Journals (Sweden)

    Yu ZHAO

    2017-09-01

    Full Text Available Background: Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis.Methods: The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10 gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI and maximum parsimony (MP. Results: Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes.Conclusion: TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  17. Cloning of resistance gene analogs located on the alien chromosome in an addition line of wheat-Thinopyrum intermedium.

    Science.gov (United States)

    Jiang, Shu-Mei; Hu, Jun; Yin, Wei-Bo; Chen, Yu-Hong; Wang, Richard R-C; Hu, Zan-Min

    2005-09-01

    -27, but it is absent in 3B-2. The ACR 3 could be used as a specific probe of the R gene on the alien chromosome of TAi-27. Results of Northern hybridization suggested that ACR 3 was constitutively expressed in Th. intermedium and TAi-27, but not 3B-2, and expressed higher in leaves than in roots. This research demonstrated a new way to clone RGAs located on a specific chromosome. The information reported here should be useful to understand the resistance mechanism of, and to clone resistant genes from, the alien chromosome in TAi-27.

  18. Combined effects of cigarette smoking, gene polymorphisms and methylations of tumor suppressor genes on non small cell lung cancer: a hospital-based case-control study in China

    International Nuclear Information System (INIS)

    Jin, Yongtang; Xu, Heyun; Zhang, Chunye; Kong, Yunming; Hou, Yong; Xu, Yingchun; Xue, Shaoli

    2010-01-01

    Cigarette smoking is the most established risk factor, and genetic variants and/or gene promoter methylations are also considered to play an essential role in development of lung cancer, but the pathogenesis of lung cancer is still unclear. We collected the data of 150 cases and 150 age-matched and sex-matched controls on a Hospital-Based Case-Control Study in China. Face to face interviews were conducted using a standardized questionnaire. Gene polymorphism and methylation status were measured by RFLP-PCR and MSP, respectively. Logistic regressive model was used to estimate the odds ratios (OR) for different levels of exposure. After adjusted age and other potential confounding factors, smoking was still main risk factor and significantly increased 3.70-fold greater risk of NSCLC as compared with nonsmokers, and the ORs across increasing levels of pack years were 1, 3.54, 3.65 and 7.76, which the general dose-response trend was confirmed. Our striking findings were that the risk increased 5.16, 8.28 and 4.10-fold, respectively, for NSCLC with promoter hypermethylation of the p16, DAPK or RARβ gene in smokers with CYP1A1 variants, and the higher risk significantly increased in smokers with null GSTM1 and the OR was 17.84 for NSCLC with p16 promoter hypermethylation, 17.41 for DAPK, and 8.18 for RARβ in smokers with null GSTM1 compared with controls (all p < 0.01). Our study suggests the strong combined effects of cigarette smoke, CYP1A1 and GSTM1 Polymorphisms, hypermethylations of p16, DAPK and RARβ promoters in NSCLC, implying complex pathogenesis of NSCLC should be given top priority in future research

  19. 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…

  20. A split hand-split foot (SHFM3) gene is located at 10q24{yields}25

    Energy Technology Data Exchange (ETDEWEB)

    Gurrieri, F.; Genuardi, M.; Nanni, L.; Sangiorgi, E.; Garofalo, G. [Catholic Univ. of Rome (Italy)] [and others

    1996-04-24

    The split hand-split foot (SHSF) malformation affects the central rays of the upper and lower limbs. It presents either as an isolated defect or in association with other skeletal or non-skeletal abnormalities. An autosomal SHSF locus (SHFM1) was previously mapped to 7q22.1. We report the mapping of a second autosomal SHSF locus to 10q24{yields}25 region. Maximum lod scores of 3.73, 4.33 and 4.33 at a recombination fraction of zero were obtained for the loci D10S198, PAX2 and D10S1239, respectively. An 19 cM critical region could be defined by haplotype analysis and several genes with a potential role in limb morphogenesis are located in this region. Heterogeneity testing indicates the existence of at least one additional autosomal SHSF locus. 36 refs., 3 figs., 3 tabs.

  1. The cartilage-derived, C-type lectin (CLECSF1): structure of the gene and chromosomal location.

    Science.gov (United States)

    Neame, P J; Tapp, H; Grimm, D R

    1999-09-03

    Cartilage is a tissue that is primarily extracellular matrix, the bulk of which consists of proteoglycan aggregates constrained within a collagen framework. Candidate components that organize the extracellular assembly of the matrix consist of collagens, proteoglycans and multimeric glycoproteins. We describe the human gene structure of a potential organizing factor, a cartilage-derived member of the C-type lectin superfamily (CLECSF1; C-type lectin superfamily) related to the serum protein, tetranectin. We show by Northern analysis that this protein is restricted to cartilage and locate the gene on chromosome 16q23. We have characterized 10.9 kb of sequence upstream of the first exon. Similarly to human tetranectin, there are three exons. The residues that are conserved between CLECSF1 and tetranectin suggest that the cartilage-derived protein forms a trimeric structure similar to that of tetranectin, with three N-terminal alpha-helical domains aggregating through hydrophobic faces. The globular, C-terminal domain that has been shown to bind carbohydrate in some members of the family and plasminogen in tetranectin, is likely to have a similar overall structure to that of tetranectin.

  2. Effects of life cycle and leaves location on gene expression and glycoside biosynthesis pathway in Stevia rebaudiana Bertoni.

    Science.gov (United States)

    Ghaheri, Matin; Adibrad, Elaheh; Safavi, Seyed Mehdi; Kahrizi, Danial; Soroush, Ali; Muhammadi, Saare; Ghorbani, Tayebeh; Sabzevari, Ali; Ansarypour, Zahra; Rahmanian, Elham

    2018-02-10

    Stevia rebaudiana Bertoni is One of the most important biologically sourced and low-calorie sweeteners that known as "Sweet Weed". It contains steviol glycosides that they are about 200-300 times sweeter than sucrose. Tissue culture is the best method with high efficiency that can overcome to problems of traditional methods, and it is the most useful tools for studying stress tolerance mechanisms under in vitro conditions to obtain drought tolerance. In the present research, we investigated the impact of life cycle, leaves location and the harvesting time on expression of UGT74G1 and UGT76G1 as well as steviol glycosides accumulation. The highest gene expression of both UGT74G1 and UGT76G1 (207.677 and 208.396 Total Lab unit, respectively) was observed in young leaves in the second vegetative year. Also, the highest amount of stevioside accumulation (13.04) was due to the old leaves in vegetative stage which had significant differences with other effects whereas the lowest accumulation (7.47) was seen at young leaves at vegetative stage. Interestingly, the highest level of rebaudioside a production (15.74) was occurred at the young leaves at vegetative stage. There was significant differences between life cycle and leaves location on steviol glycoside production in stevia.

  3. Identification of a novel intergenic miRNA located between the human DDC and COBL genes with a potential function in cell cycle arrest.

    Science.gov (United States)

    Hoballa, Mohamad Hussein; Soltani, Bahram M; Mowla, Seyed Javad; Sheikhpour, Mojgan; Kay, Maryam

    2018-07-01

    Frequent abnormalities in 7p12 locus in different tumors like lung cancer candidate this region for novel regulatory elements. MiRNAs as novel regulatory elements encoded within the human genome are potentially oncomiRs or miR suppressors. Here, we have used bioinformatics tools to search for the novel miRNAs embedded within human chromosome 7p12. A bona fide stem loop (named mirZa precursor) had the features of producing a real miRNA (named miRZa) which was detected through RT-qPCR following the overexpression of its precursor. Then, endogenous miRZa was detected in human cell lines and tissues and sequenced. Consistent to the bioinformatics prediction, RT-qPCR as well as dual luciferase assay indicated that SMAD3 and IGF1R genes were targeted by miRZa. MiRZa-3p and miRZa-5p were downregulated in lung tumor tissue samples detected by RT-qPCR, and mirZa precursor overexpression in SW480 cells resulted in increased sub-G1 cell population. Overall, here we introduced a novel miRNA which is capable of targeting SMAD3 and IGF1R regulatory genes and increases the cell population in sub-G1 stage.

  4. Comparative genomic mapping of the bovine Fragile Histidine Triad (FHIT tumour suppressor gene: characterization of a 2 Mb BAC contig covering the locus, complete annotation of the gene, analysis of cDNA and of physiological expression profiles

    Directory of Open Access Journals (Sweden)

    Boussaha Mekki

    2006-05-01

    Full Text Available Abstract Background The Fragile Histidine Triad gene (FHIT is an oncosuppressor implicated in many human cancers, including vesical tumors. FHIT is frequently hit by deletions caused by fragility at FRA3B, the most active of human common fragile sites, where FHIT lays. Vesical tumors affect also cattle, including animals grazing in the wild on bracken fern; compounds released by the fern are known to induce chromosome fragility and may trigger cancer with the interplay of latent Papilloma virus. Results The bovine FHIT was characterized by assembling a contig of 78 BACs. Sequence tags were designed on human exons and introns and used directly to select bovine BACs, or compared with sequence data in the bovine genome database or in the trace archive of the bovine genome sequencing project, and adapted before use. FHIT is split in ten exons like in man, with exons 5 to 9 coding for a 149 amino acids protein. VISTA global alignments between bovine genomic contigs retrieved from the bovine genome database and the human FHIT region were performed. Conservation was extremely high over a 2 Mb region spanning the whole FHIT locus, including the size of introns. Thus, the bovine FHIT covers about 1.6 Mb compared to 1.5 Mb in man. Expression was analyzed by RT-PCR and Northern blot, and was found to be ubiquitous. Four cDNA isoforms were isolated and sequenced, that originate from an alternative usage of three variants of exon 4, revealing a size very close to the major human FHIT cDNAs. Conclusion A comparative genomic approach allowed to assemble a contig of 78 BACs and to completely annotate a 1.6 Mb region spanning the bovine FHIT gene. The findings confirmed the very high level of conservation between human and bovine genomes and the importance of comparative mapping to speed the annotation process of the recently sequenced bovine genome. The detailed knowledge of the genomic FHIT region will allow to study the role of FHIT in bovine cancerogenesis

  5. Comparative genomic mapping of the bovine Fragile Histidine Triad (FHIT) tumour suppressor gene: characterization of a 2 Mb BAC contig covering the locus, complete annotation of the gene, analysis of cDNA and of physiological expression profiles.

    Science.gov (United States)

    Uboldi, Cristina; Guidi, Elena; Roperto, Sante; Russo, Valeria; Roperto, Franco; Di Meo, Giulia Pia; Iannuzzi, Leopoldo; Floriot, Sandrine; Boussaha, Mekki; Eggen, André; Ferretti, Luca

    2006-05-23

    The Fragile Histidine Triad gene (FHIT) is an oncosuppressor implicated in many human cancers, including vesical tumors. FHIT is frequently hit by deletions caused by fragility at FRA3B, the most active of human common fragile sites, where FHIT lays. Vesical tumors affect also cattle, including animals grazing in the wild on bracken fern; compounds released by the fern are known to induce chromosome fragility and may trigger cancer with the interplay of latent Papilloma virus. The bovine FHIT was characterized by assembling a contig of 78 BACs. Sequence tags were designed on human exons and introns and used directly to select bovine BACs, or compared with sequence data in the bovine genome database or in the trace archive of the bovine genome sequencing project, and adapted before use. FHIT is split in ten exons like in man, with exons 5 to 9 coding for a 149 amino acids protein. VISTA global alignments between bovine genomic contigs retrieved from the bovine genome database and the human FHIT region were performed. Conservation was extremely high over a 2 Mb region spanning the whole FHIT locus, including the size of introns. Thus, the bovine FHIT covers about 1.6 Mb compared to 1.5 Mb in man. Expression was analyzed by RT-PCR and Northern blot, and was found to be ubiquitous. Four cDNA isoforms were isolated and sequenced, that originate from an alternative usage of three variants of exon 4, revealing a size very close to the major human FHIT cDNAs. A comparative genomic approach allowed to assemble a contig of 78 BACs and to completely annotate a 1.6 Mb region spanning the bovine FHIT gene. The findings confirmed the very high level of conservation between human and bovine genomes and the importance of comparative mapping to speed the annotation process of the recently sequenced bovine genome. The detailed knowledge of the genomic FHIT region will allow to study the role of FHIT in bovine cancerogenesis, especially of vesical papillomavirus-associated cancers of

  6. HybridGO-Loc: mining hybrid features on gene ontology for predicting subcellular localization of multi-location proteins.

    Science.gov (United States)

    Wan, Shibiao; Mak, Man-Wai; Kung, Sun-Yuan

    2014-01-01

    Protein subcellular localization prediction, as an essential step to elucidate the functions in vivo of proteins and identify drugs targets, has been extensively studied in previous decades. Instead of only determining subcellular localization of single-label proteins, recent studies have focused on predicting both single- and multi-location proteins. Computational methods based on Gene Ontology (GO) have been demonstrated to be superior to methods based on other features. However, existing GO-based methods focus on the occurrences of GO terms and disregard their relationships. This paper proposes a multi-label subcellular-localization predictor, namely HybridGO-Loc, that leverages not only the GO term occurrences but also the inter-term relationships. This is achieved by hybridizing the GO frequencies of occurrences and the semantic similarity between GO terms. Given a protein, a set of GO terms are retrieved by searching against the gene ontology database, using the accession numbers of homologous proteins obtained via BLAST search as the keys. The frequency of GO occurrences and semantic similarity (SS) between GO terms are used to formulate frequency vectors and semantic similarity vectors, respectively, which are subsequently hybridized to construct fusion vectors. An adaptive-decision based multi-label support vector machine (SVM) classifier is proposed to classify the fusion vectors. Experimental results based on recent benchmark datasets and a new dataset containing novel proteins show that the proposed hybrid-feature predictor significantly outperforms predictors based on individual GO features as well as other state-of-the-art predictors. For readers' convenience, the HybridGO-Loc server, which is for predicting virus or plant proteins, is available online at http://bioinfo.eie.polyu.edu.hk/HybridGoServer/.

  7. 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

  8. 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

  9. Association between mutations of critical pathway genes and survival outcomes according to the tumor location in colorectal cancer.

    Science.gov (United States)

    Lee, Dae-Won; Han, Sae-Won; Cha, Yongjun; Bae, Jeong Mo; Kim, Hwang-Phill; Lyu, Jaemyun; Han, Hyojun; Kim, Hyoki; Jang, Hoon; Bang, Duhee; Huh, Iksoo; Park, Taesung; Won, Jae-Kyung; Jeong, Seung-Yong; Park, Kyu Joo; Kang, Gyeong Hoon; Kim, Tae-You

    2017-09-15

    Colorectal cancer (CRC) develops through the alteration of several critical pathways. This study was aimed at evaluating the influence of critical pathways on survival outcomes for patients with CRC. Targeted next-generation sequencing of 40 genes included in the 5 critical pathways of CRC (WNT, P53, RTK-RAS, phosphatidylinositol-4,5-bisphosphate 3-kinase [PI3K], and transforming growth factor β [TGF-β]) was performed for 516 patients with stage III or high-risk stage II CRC treated with surgery followed by adjuvant fluoropyrimidine and oxaliplatin chemotherapy. The associations between critical pathway mutations and relapse-free survival (RFS) and overall survival were analyzed. The associations were further analyzed according to the tumor location. The mutation rates for the WNT, P53, RTK-RAS, PI3K, and TGF-β pathways were 84.5%, 69.0%, 60.7%, 30.0%, and 28.9%, respectively. A mutation in the PI3K pathway was associated with longer RFS (adjusted hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.36-0.99), whereas a mutation in the RTK-RAS pathway was associated with shorter RFS (adjusted HR, 1.60; 95% CI, 1.01-2.52). Proximal tumors showed a higher mutation rate than distal tumors, and the mutation profile was different according to the tumor location. The mutation rates of Kirsten rat sarcoma viral oncogene homolog (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), and B-Raf proto-oncogene serine/threonine kinase (BRAF) were higher in proximal tumors, and the mutation rates of adenomatous polyposis coli (APC), tumor protein 53 (TP53), and neuroblastoma RAS viral oncogene homolog (NRAS) were higher in distal tumors. The better RFS with the PI3K pathway mutation was significant only for proximal tumors, and the worse RFS with the RTK-RAS pathway mutation was significant only for distal tumors. A PI3K pathway mutation was associated with better RFS for CRC patients treated with adjuvant chemotherapy, and an RTK

  10. 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

  11. Impact of transgene genome location on gene migration from herbicide-resistant wheat (Triticum aestivum L.) to jointed goatgrass (Aegilops cylindrica Host).

    Science.gov (United States)

    Rehman, Maqsood; Hansen, Jennifer L; Mallory-Smith, Carol A; Zemetra, Robert S

    2017-08-01

    Wheat (Triticum aestivum) (ABD) and jointed goatgrass (Aegilops cylindrica) (CD) can cross and produce hybrids that can backcross to either parent. Such backcrosses can result in progeny with chromosomes and/or chromosome segments retained from wheat. Thus, a herbicide resistance gene could migrate from wheat to jointed goatgrass. In theory, the risk of gene migration from herbicide-resistant wheat to jointed goatgrass is more likely if the gene is located on the D genome and less likely if the gene is located on the A or B genome of wheat. BC 1 populations (jointed goatgrass as a recurrent parent) were analyzed for chromosome numbers and transgene transmission rates under sprayed and non-sprayed conditions. Transgene retention in the non-sprayed BC 1 generation for the A, B and D genomes was 84, 60 and 64% respectively. In the sprayed populations, the retention was 81, 59 and 74% respectively. The gene transmission rates were higher than the expected 50% or less under sprayed and non-sprayed conditions, possibly owing to meiotic chromosome restitution and/or chromosome non-disjunction. Such high transmission rates in the BC 1 generation negates the benefits of gene placement for reducing the potential of gene migration from wheat to jointed goatgrass. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. CTX-M-1 β-lactamase expression in Escherichia coli is dependent on cefotaxime concentration, growth phase and gene location

    DEFF Research Database (Denmark)

    Kjeldsen, Thea S. B.; Overgaard, Martin; Nielsen, Søren S.

    2015-01-01

    blaCTX-M-1 mRNA expression and CTX-M-1 protein levels were dependent on cefotaxime concentration, growth phase and gene location. These results provide insight into the expression of cephalosporin resistance in CTX-M-1-producing E. coli, improving our understanding of the relationship between ant...

  13. Chromosome locations of genes encoding human signal transduction adapter proteins, Nck (NCK), Shc (SHC1), and Grb2 (GRB2)

    DEFF Research Database (Denmark)

    Huebner, K; Kastury, K; Druck, T

    1994-01-01

    "adapter" proteins, which are involved in transducing signals from receptor tyrosine kinases to downstream signal recipients such as ras, because adaptor protein genes could also, logically, serve as targets of mutation, rearrangement, or other aberration in disease. Therefore, DNAs from panels of rodent-human......Abnormalities due to chromosomal aberration or point mutation in gene products of growth factor receptors or in ras gene products, which lie on the same signaling pathway, can cause disease in animals and humans. Thus, it can be important to determine chromosomal map positions of genes encoding...... hybrids carrying defined complements of human chromosomes were assayed for the presence of the cognate genes for NCK, SHC, and GRB2, three SH2 or SH2/SH3 (Src homology 2 and 3) domain-containing adapter proteins. Additionally, NCK and SHC genes were more narrowly localized by chromosomal in situ...

  14. 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

  15. Different waves of effector genes with contrasted genomic location are expressed by Leptosphaeria maculans during cotyledon and stem colonization of oilseed rape.

    Science.gov (United States)

    Gervais, Julie; Plissonneau, Clémence; Linglin, Juliette; Meyer, Michel; Labadie, Karine; Cruaud, Corinne; Fudal, Isabelle; Rouxel, Thierry; Balesdent, Marie-Hélène

    2017-10-01

    Leptosphaeria maculans, the causal agent of stem canker disease, colonizes oilseed rape (Brassica napus) in two stages: a short and early colonization stage corresponding to cotyledon or leaf colonization, and a late colonization stage during which the fungus colonizes systemically and symptomlessly the plant during several months before stem canker appears. To date, the determinants of the late colonization stage are poorly understood; L. maculans may either successfully escape plant defences, leading to stem canker development, or the plant may develop an 'adult-stage' resistance reducing canker incidence. To obtain an insight into these determinants, we performed an RNA-sequencing (RNA-seq) pilot project comparing fungal gene expression in infected cotyledons and in symptomless or necrotic stems. Despite the low fraction of fungal material in infected stems, sufficient fungal transcripts were detected and a large number of fungal genes were expressed, thus validating the feasibility of the approach. Our analysis showed that all avirulence genes previously identified are under-expressed during stem colonization compared with cotyledon colonization. A validation RNA-seq experiment was then performed to investigate the expression of candidate effector genes during systemic colonization. Three hundred and seven 'late' effector candidates, under-expressed in the early colonization stage and over-expressed in the infected stems, were identified. Finally, our analysis revealed a link between the regulation of expression of effectors and their genomic location: the 'late' effector candidates, putatively involved in systemic colonization, are located in gene-rich genomic regions, whereas the 'early' effector genes, over-expressed in the early colonization stage, are located in gene-poor regions of the genome. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  16. 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

  17. 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

  18. 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

  19. The New Macrolide-Lincosamide-Streptogramin B Resistance Gene erm(45) Is Located within a Genomic Island in Staphylococcus fleurettii

    DEFF Research Database (Denmark)

    Wipf, Juliette R K; Schwendener, Sybille; Nielsen, Jesper Boye

    2015-01-01

    Genome alignment of a macrolide, lincosamide, and streptogramin B (MLSB)-resistant Staphylococcus fleurettii strain with an MLSB-susceptible S. fleurettii strain revealed a novel 11,513-bp genomic island carrying the new erythromycin resistance methylase gene erm(45). This gene was shown to confer...... inducible MLSB resistance when cloned into Staphylococcus aureus. The erm(45)-containing island was integrated into the housekeeping gene guaA in S. fleurettii and was able to form a circular intermediate but was not transmissible to S. aureus....

  20. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16(INK4a) gene in human colorectal carcinoma (Caco-2) cells.

    Science.gov (United States)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A

    2014-07-18

    Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC50 400±25 mg fresh pulp equivalents/mL, and 115±15 μM (n=9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16(INK4a) gene promoter, reactivation of the silenced mRNA expression and accumulation of p16(INK4a), a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Development of a new fluorescent reporter:operator system: location of AraC regulated genes in Escherichia coli K-12.

    Science.gov (United States)

    Sellars, Laura E; Bryant, Jack A; Sánchez-Romero, María-Antonia; Sánchez-Morán, Eugenio; Busby, Stephen J W; Lee, David J

    2017-08-03

    In bacteria, many transcription activator and repressor proteins regulate multiple transcription units that are often distally distributed on the bacterial genome. To investigate the subcellular location of DNA bound proteins in the folded bacterial nucleoid, fluorescent reporters have been developed which can be targeted to specific DNA operator sites. Such Fluorescent Reporter-Operator System (FROS) probes consist of a fluorescent protein fused to a DNA binding protein, which binds to an array of DNA operator sites located within the genome. Here we have developed a new FROS probe using the Escherichia coli MalI transcription factor, fused to mCherry fluorescent protein. We have used this in combination with a LacI repressor::GFP protein based FROS probe to assess the cellular location of commonly regulated transcription units that are distal on the Escherichia coli genome. We developed a new DNA binding fluorescent reporter, consisting of the Escherichia coli MalI protein fused to the mCherry fluorescent protein. This was used in combination with a Lac repressor:green fluorescent protein fusion to examine the spatial positioning and possible co-localisation of target genes, regulated by the Escherichia coli AraC protein. We report that induction of gene expression with arabinose does not result in co-localisation of AraC-regulated transcription units. However, measurable repositioning was observed when gene expression was induced at the AraC-regulated promoter controlling expression of the araFGH genes, located close to the DNA replication terminus on the chromosome. Moreover, in dividing cells, arabinose-induced expression at the araFGH locus enhanced chromosome segregation after replication. Regions of the chromosome regulated by AraC do not colocalise, but transcription events can induce movement of chromosome loci in bacteria and our observations suggest a role for gene expression in chromosome segregation.

  2. HLXB9 gene expression, and nuclear location during in vitro neuronal differentiation in the SK-N-BE neuroblastoma cell line.

    Directory of Open Access Journals (Sweden)

    Claudia Giovanna Leotta

    Full Text Available Different parts of the genome occupy specific compartments of the cell nucleus based on the gene content and the transcriptional activity. An example of this is the altered nuclear positioning of the HLXB9 gene in leukaemia cells observed in association with its over-expression. This phenomenon was attributed to the presence of a chromosomal translocation with breakpoint proximal to the HLXB9 gene. Before becoming an interesting gene in cancer biology, HLXB9 was studied as a developmental gene. This homeobox gene is also known as MNX1 (motor neuron and pancreas homeobox 1 and it is relevant for both motor neuronal and pancreatic beta cells development. A spectrum of mutations in this gene are causative of sacral agenesis and more broadly, of what is known as the Currarino Syndrome, a constitutional autosomal dominant disorder. Experimental work on animal models has shown that HLXB9 has an essential role in motor neuronal differentiation. Here we present data to show that, upon treatment with retinoic acid, the HLXB9 gene becomes over-expressed during the early stages of neuronal differentiation and that this corresponds to a reposition of the gene in the nucleus. More precisely, we used the SK-N-BE human neuroblastoma cell line as an in vitro model and we demonstrated a transient transcription of HLXB9 at the 4th and 5th days of differentiation that corresponded to the presence, predominantly in the cell nuclei, of the encoded protein HB9. The nuclear positioning of the HLXB9 gene was monitored at different stages: a peripheral location was noted in the proliferating cells whereas a more internal position was noted during differentiation, that is while HLXB9 was transcriptionally active. Our findings suggest that HLXB9 can be considered a marker of early neuronal differentiation, possibly involving chromatin remodeling pathways.

  3. Location, location ... structure

    NARCIS (Netherlands)

    Cutler, S.; Testerink, C.

    2011-01-01

    A plant's growth, development and responses to the environment are intimately connected to internal and external signals that, through the action of signal transduction, regulate gene expression and other cellular outputs. Work from laboratories across the globe has deepened our understanding of how

  4. 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

  5. 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.

  6. The fosfomycin resistance gene fosB3 is located on a transferable, extrachromosomal circular intermediate in clinical Enterococcus faecium isolates.

    Directory of Open Access Journals (Sweden)

    Xiaogang Xu

    Full Text Available Some VanM-type vancomycin-resistant Enterococcus faecium isolates from China are also resistant to fosfomycin. To investigate the mechanism of fosfomycin resistance in these clinical isolates, antimicrobial susceptibility testing, filter-mating, Illumina/Solexa sequencing, inverse PCR and fosfomycin resistance gene cloning were performed. Three E. faecium clinical isolates were highly resistant to fosfomycin and vancomycin with minimal inhibitory concentrations (MICs >1024 µg/ml and >256 µg/ml, respectively. The fosfomycin and vancomycin resistance of these strains could be co-transferred by conjugation. They carried a fosfomycin resistance gene fosB encoding a protein differing by one or two amino acids from FosB, which is encoded on staphylococcal plasmids. Accordingly, the gene was designated fosB3. The fosB3 gene was cloned into pMD19-T, and transformed into E. coli DH5α. The fosfomycin MIC for transformants with fosB3 was 750-fold higher than transformants without fosB3. The fosB3 gene could be transferred by an extrachromosomal circular intermediate. The results indicate that the fosB3 gene is transferable, can mediate high level fosfomycin resistance in both Gram-positive and Gram-negative bacteria, and can be located on a circular intermediate.

  7. Haloalkane-utilizing Rhodococcus strains isolated from geographically distinct locations possess a highly conserved gene cluster encoding haloalkane catabolism

    NARCIS (Netherlands)

    Poelarends, GJ; Bosma, T; Kulakov, LA; Larkin, MJ; Marchesi, [No Value; Weightman, AJ; Janssen, DB; Kulakov, Leonid A.; Larkin, Michael J.; Marchesi, Julian R.; Weightman, Andrew J.

    The sequences of the 16S rRNA and haloalkane dehalogenase (dhaA) genes of five gram-positive haloalkane-utilizing bacteria isolated from contaminated sites in Europe, Japan, and the United States and of the archetypal haloalkane-degrading bacterium Rhodococcus sp. strain NCIMB13064 were compared.

  8. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16{sup INK4a} gene in human colorectal carcinoma (Caco-2) cells

    Energy Technology Data Exchange (ETDEWEB)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A., E-mail: maria.livrea@unipa.it

    2014-07-18

    Highlights: • Cactus pear fruit extract and indicaxanthin cause apoptosis of colon cancer cells. • Indicaxanthin does not cause ROS formation, but affects epigenoma in Caco-2 cells. • Indicaxanthin reverses methylation of oncosuppressor p16{sup INK4a} gene in Caco-2 cells. • Indicaxanthin reactivates retinoblastoma in Caco-2 cells. • Bioavailable indicaxanthin may have chemopreventive activity in colon cancer. - Abstract: Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC{sub 50} 400 ± 25 mg fresh pulp equivalents/mL, and 115 ± 15 μM (n = 9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16{sup INK4a} gene promoter, reactivation of the silenced mRNA expression and accumulation of p16{sup INK4a}, a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells.

  9. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16INK4a gene in human colorectal carcinoma (Caco-2) cells

    International Nuclear Information System (INIS)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A.

    2014-01-01

    Highlights: • Cactus pear fruit extract and indicaxanthin cause apoptosis of colon cancer cells. • Indicaxanthin does not cause ROS formation, but affects epigenoma in Caco-2 cells. • Indicaxanthin reverses methylation of oncosuppressor p16 INK4a gene in Caco-2 cells. • Indicaxanthin reactivates retinoblastoma in Caco-2 cells. • Bioavailable indicaxanthin may have chemopreventive activity in colon cancer. - Abstract: Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC 50 400 ± 25 mg fresh pulp equivalents/mL, and 115 ± 15 μM (n = 9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16 INK4a gene promoter, reactivation of the silenced mRNA expression and accumulation of p16 INK4a , a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells

  10. The Mapping of Predicted Triplex DNA:RNA in the Drosophila Genome Reveals a Prominent Location in Development- and Morphogenesis-Related Genes

    Directory of Open Access Journals (Sweden)

    Claude Pasquier

    2017-07-01

    Full Text Available Double-stranded DNA is able to form triple-helical structures by accommodating a third nucleotide strand. A nucleic acid triplex occurs according to Hoogsteen rules that predict the stability and affinity of the third strand bound to the Watson–Crick duplex. The “triplex-forming oligonucleotide” (TFO can be a short sequence of RNA that binds to the major groove of the targeted duplex only when this duplex presents a sequence of purine or pyrimidine bases in one of the DNA strands. Many nuclear proteins are known to bind triplex DNA or DNA:RNA, but their biological functions are unexplored. We identified sequences that are capable of engaging as the “triplex-forming oligonucleotide” in both the pre-lncRNA and pre-mRNA collections of Drosophila melanogaster. These motifs were matched against the Drosophila genome in order to identify putative sequences of triplex formation in intergenic regions, promoters, and introns/exons. Most of the identified TFOs appear to be located in the intronic region of the analyzed genes. Computational prediction of the most targeted genes by TFOs originating from pre-lncRNAs and pre-mRNAs revealed that they are restrictively associated with development- and morphogenesis-related gene networks. The refined analysis by Gene Ontology enrichment demonstrates that some individual TFOs present genome-wide scale matches that are located in numerous genes and regulatory sequences. The triplex DNA:RNA computational mapping at the genome-wide scale suggests broad interference in the regulatory process of the gene networks orchestrated by TFO RNAs acting in association simultaneously at multiple sites.

  11. 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.

  12. Characterization of a canine tetranucleotide microsatellite marker located in the first intron of the tumor necrosis factor alpha gene.

    Science.gov (United States)

    Watanabe, Masashi; Tanaka, Kazuaki; Takizawa, Tatsuya; Segawa, Kazuhito; Neo, Sakurako; Tsuchiya, Ryo; Murata, Michiko; Murakami, Masaru; Hisasue, Masaharu

    2014-01-01

    A polymorphic tetranucleotide (GAAT)n microsatellite in the first intron of the canine tumor necrosis factor alpha (TNFA) gene was characterized in this study; 139 dogs were analyzed: 22 Beagles, 26 Chihuahuas, 20 Miniature Dachshunds, 24 Miniature Poodles, 22 Pembroke Welsh Corgis and 25 Shiba Inus. We detected the presence of the 4 alleles (GAAT)5, (GAAT)6, (GAAT)7 and (GAAT)8, including 9 of the 10 expected genotypes. The expected heterozygosity (He) and the polymorphic information content (PIC) value of this microsatellite locus varied from 0.389 to 0.749 and from 0.333 to 0.682, respectively, among the 6 breeds. The allelic frequency differed greatly among breeds, but this microsatellite marker was highly polymorphic and could be a useful marker for the canine TNFA gene.

  13. Characterization of a Canine Tetranucleotide Microsatellite Marker Located in the First Intron of the Tumor Necrosis Factor Alpha Gene

    OpenAIRE

    WATANABE, Masashi; TANAKA, Kazuaki; TAKIZAWA, Tatsuya; SEGAWA, Kazuhito; NEO, Sakurako; TSUCHIYA, Ryo; MURATA, Michiko; MURAKAMI, Masaru; HISASUE, Masaharu

    2013-01-01

    ABSTRACT A polymorphic tetranucleotide (GAAT)n microsatellite in the first intron of the canine tumor necrosis factor alpha (TNFA) gene was characterized in this study; 139 dogs were analyzed: 22 Beagles, 26 Chihuahuas, 20 Miniature Dachshunds, 24 Miniature Poodles, 22 Pembroke Welsh Corgis and 25 Shiba Inus. We detected the presence of the 4 alleles (GAAT)5, (GAAT)6, (GAAT)7 and (GAAT)8, including 9 of the 10 expected genotypes. The expected heterozygosity (He) and the polymorphic informatio...

  14. BanII dimorphic site located in the third intron of the human apolipoprotein AI (APOA1) gene

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, R T; Kresnak, M T; Frossard, P M

    1988-02-11

    A 0.7kb fragment generated by AvaII digestion of pBL13AI, a 0.965kb full-length human apolipoprotein AI cDNA was cloned into the EcoRI site of pBR322. The apoAI cDNA was isolated from a lambdagt10 human fetal liver cDNA library. BanII (GPuGCPyC) (International Biotechnologies, Inc.) identifies two invariant bands at 1122bp and 417bp, and a single two-allele polymorphism with bands at either 274bp or 452bp. The human apolipoprotein AI-CIII-AIV gene complex has been localized on the long arm of chromosome 11 by Southern blot analysis of human-chinese hamster cell hybrids. Co-dominant segregation has been observed in two families (13 individuals). The BanII restriction map was constructed from DNA sequence data of the human apoAI gene. The 452bp fragment is generated by the loss of a BanII dimorphic site in the third intron of the apoAI gene, between the 178bp and the 274bp fragments.

  15. A storage-protein marker associated with the suppressor of Pm8 for powdery mildew resistance in wheat.

    Science.gov (United States)

    Ren, S X; McIntosh, R A; Sharp, P J; The, T T

    1996-11-01

    A suppressor of resistance to powdery mildew conferred by Pm8 showed complete association with the presence of a storage-protein marker resolved by electrophoresis on SDS-PAGE gels. This marker was identified as the product of the gliadin allele Gli-A1a. The mildewresponse phenotypes of wheats possessing the 1BL.1RS translocation were completely predictable from electrophoretograms. The suppressor, designated SuPm8, was located on chromosome 1AS. It was specific in its suppression of Pm8, and did not affect the rye-derived resistance phenotypes of wheat lines with Pm17, also located in 1RS, or of lines with Pm7.

  16. 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.

  17. Plasminogen activator inhibitor type 1 gene is located at region q21.3-q22 of chromosome 7 and genetically linked with cystic fibrosis

    International Nuclear Information System (INIS)

    Klinger, K.W.; Winqvist, R.; Riccio, A.

    1987-01-01

    The regional chromosomal location of the human gene for plasminogen activator inhibitor type 1 (PAI1) was determined by three independent methods of gene mapping. PAI1 was localized first to 7cen-q32 and then to 7q21.3-q22 by Southern blot hybridization analysis of a panel of human and mouse somatic cell hybrids with a PAI1 cDNA probe and in situ hybridization, respectively. The authors frequent HindIII restriction fragment length polymorphism (RFLP) of the PAI1 gene with an information content of 0.369. In family studies using this polymorphism, genetic linkage was found between PAI1 and the loci for erythropoietin (EPO), paraoxonase (PON), the met protooncogene (MET), and cystic fibrosis (CF), all previously assigned to the middle part of the long arm of chromosome 7. The linkage with EPO was closest with an estimated genetic distance of 3 centimorgans, whereas that to CF was 20 centimorgans. A three-point genetic linkage analysis and data from previous studies showed that the most likely order of these loci is EPO, PAI1, PON, (MET, CF), with PAI1 being located centromeric to CF. The PAI1 RFLP may prove to be valuable in ordering genetic markers in the CF-linkage group and may also be valuable in genetic analysis of plasminogen activation-related diseases, such as certain thromboembolic disorders and cancer

  18. Upregulation of Oxidative Stress Related Genes in a Chronic Kidney Disease Attributed to Specific Geographical Locations of Sri Lanka

    Directory of Open Access Journals (Sweden)

    Saravanabavan Sayanthooran

    2016-01-01

    Full Text Available Objective. To infer the influence of internal and external oxidative stress in chronic kidney disease patients of unknown etiology (CKDu in Sri Lanka, by analyzing expression of genes related directly or indirectly to oxidative stress: glutamate-cysteine ligase catalytic subunit (GCLC, glutathione S-transferase mu 1 (GSTM1, glucose-6-phosphate dehydrogenase (G6PD, fibroblast growth factor-23 (FGF23, and NLR family pyrin domain containing 3 (NLRP3. Methods. Reverse transcription quantitative polymerase chain reaction (RT-qPCR was carried out for the selected populations: CKDu patients (n=43, chronic kidney disease patients (CKD; n=14, healthy individuals from a CKDu endemic area (GHI; n=9, and nonendemic area (KHI; n=16. Fold changes were quantified relative to KHI. Results. GCLC had greater than threefold upregulation in all three study groups, with a maximum of 7.27-fold upregulation in GHI (p=0.000. GSTM1 was not expressed in 25.6% of CKDu and 42.9% of CKD patients, but CKDu patients expressing GSTM1 showed upregulation of 2.60-fold (p<0.05. Upregulation of FGF23 and NLRP3 genes in CKD and CKDu was observed (p<0.01, with greater fold changes in CKD. Conclusion. Results suggest higher influence of external sources of oxidative stress in CKDu, possibly owing to environmental conditions.

  19. Characterization of Plasmid DNA Location within Chitosan/PLGA/pDNA Nanoparticle Complexes Designed for Gene Delivery

    Directory of Open Access Journals (Sweden)

    Hali Bordelon

    2011-01-01

    Full Text Available Poly(D,L-lactide-co-glycolide- (PLGA-chitosan nanoparticles are becoming an increasingly common choice for the delivery of nucleic acids to cells for various genetic manipulation techniques. These particles are biocompatible, with tunable size and surface properties, possessing an overall positive charge that promotes complex formation with negatively charged nucleic acids. This study examines properties of the PLGA-chitosan nanoparticle/plasmid DNA complex after formation. Specifically, the study aims to determine the optimal ratio of plasmid DNA:nanoparticles for nucleic acid delivery purposes and to elucidate the location of the pDNA within these complexes. Such characterization will be necessary for the adoption of these formulations in a clinical setting. The ability of PLGA-chitosan nanoparticles to form complexes with pDNA was evaluated by using the fluorescent intercalating due OliGreen to label free plasmid DNA. By monitoring the fluorescence at different plasmid: nanoparticle ratios, the ideal plasmid:nanoparticle ration for complete complexation of plasmid was determined to be 1:50. Surface-Enhanced Raman Spectroscopy and gel digest studies suggested that even at these optimal complexation ratios, a portion of the plasmid DNA was located on the outer complex surface. This knowledge will facilitate future investigations into the functionality of the system in vitro and in vivo.

  20. 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

  1. The Use of a Combined Bioinformatics Approach to Locate Antibiotic Resistance Genes on Plasmids From Whole Genome Sequences of Salmonella enterica Serovars From Humans in Ghana

    Directory of Open Access Journals (Sweden)

    Egle Kudirkiene

    2018-05-01

    Full Text Available In the current study, we identified plasmids carrying antimicrobial resistance genes in draft whole genome sequences of 16 selected Salmonella enterica isolates representing six different serovars from humans in Ghana. The plasmids and the location of resistance genes in the genomes were predicted using a combination of PlasmidFinder, ResFinder, plasmidSPAdes and BLAST genomic analysis tools. Subsequently, S1-PFGE was employed for analysis of plasmid profiles. Whole genome sequencing confirmed the presence of antimicrobial resistance genes in Salmonella isolates showing multidrug resistance phenotypically. ESBL, either blaTEM52−B or blaCTX−M15 were present in two cephalosporin resistant isolates of S. Virchow and S. Poona, respectively. The systematic genome analysis revealed the presence of different plasmids in different serovars, with or without insertion of antimicrobial resistance genes. In S. Enteritidis, resistance genes were carried predominantly on plasmids of IncN type, in S. Typhimurium on plasmids of IncFII(S/IncFIB(S/IncQ1 type. In S. Virchow and in S. Poona, resistance genes were detected on plasmids of IncX1 and TrfA/IncHI2/IncHI2A type, respectively. The latter two plasmids were described for the first time in these serovars. The combination of genomic analytical tools allowed nearly full mapping of the resistance plasmids in all Salmonella strains analyzed. The results suggest that the improved analytical approach used in the current study may be used to identify plasmids that are specifically associated with resistance phenotypes in whole genome sequences. Such knowledge would allow the development of rapid multidrug resistance tracking tools in Salmonella populations using WGS.

  2. NcoI dimorphic site located 8kb 3' to the human apolipoprotein AIV (APOA4) gene

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, R T; Malloy, M J; Kane, J P; Frossard, P M

    1988-02-11

    pA4C3 a 0.5kb fragment from the 3' end of the human apolipoprotein AIV cDNA was isolated from a human intestine cDNA library and cloned into the EcoRI site of the plasmid pUC18. NcoI (CCATGG) (New England Biolabs) detects a single two-allele polymorphism with a band at either 18.6kb or at 12.6kb. The human apolipoprotein AI-CIII-AIV gene complex has been assigned to the long arm of chromosome 11 by Southern blot analysis of human-Chinese hamster cell hybrids. Co-dominant segregation was demonstrated in one family of six individuals.

  3. Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within the HERC2 gene inhibiting OCA2 expression

    DEFF Research Database (Denmark)

    Eiberg, Hans; Troelsen, Jesper; Boyd, Mette

    2008-01-01

    The human eye color is a quantitative trait displaying multifactorial inheritance. Several studies have shown that the OCA2 locus is the major contributor to the human eye color variation. By linkage analysis of a large Danish family, we finemapped the blue eye color locus to a 166 Kbp region...... within the HERC2 gene. By association analyses, we identified two SNPs within this region that were perfectly associated with the blue and brown eye colors: rs12913832 and rs1129038. Of these, rs12913832 is located 21.152 bp upstream from the OCA2 promoter in a highly conserved sequence in intron 86...... founder mutation in an OCA2 inhibiting regulatory element as the cause of blue eye color in humans. In addition, an LOD score of Z = 4.21 between hair color and D14S72 was obtained in the large family, indicating that RABGGTA is a candidate gene for hair color....

  4. 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.

  5. 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.

  6. Upregulation of Oxidative Stress Related Genes in a Chronic Kidney Disease Attributed to Specific Geographical Locations of Sri Lanka.

    Science.gov (United States)

    Sayanthooran, Saravanabavan; Magana-Arachchi, Dhammika N; Gunerathne, Lishanthe; Abeysekera, Tilak D J; Sooriyapathirana, Suneth S

    2016-01-01

    Objective. To infer the influence of internal and external oxidative stress in chronic kidney disease patients of unknown etiology (CKDu) in Sri Lanka, by analyzing expression of genes related directly or indirectly to oxidative stress: glutamate-cysteine ligase catalytic subunit (GCLC), glutathione S-transferase mu 1 (GSTM1), glucose-6-phosphate dehydrogenase (G6PD), fibroblast growth factor-23 (FGF23), and NLR family pyrin domain containing 3 (NLRP3). Methods. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was carried out for the selected populations: CKDu patients ( n = 43), chronic kidney disease patients (CKD; n = 14), healthy individuals from a CKDu endemic area (GHI; n = 9), and nonendemic area (KHI; n = 16). Fold changes were quantified relative to KHI. Results. GCLC had greater than threefold upregulation in all three study groups, with a maximum of 7.27-fold upregulation in GHI ( p = 0.000). GSTM1 was not expressed in 25.6% of CKDu and 42.9% of CKD patients, but CKDu patients expressing GSTM1 showed upregulation of 2.60-fold ( p CKDu was observed ( p CKDu, possibly owing to environmental conditions.

  7. 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.

  8. 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.

  9. 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 ...

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. Expression of human kinase suppressor of Ras 2 (hKSR-2) gene in HL60 leukemia cells is directly upregulated by 1,25-dihydroxyvitamin D3 and is required for optimal cell differentiation

    International Nuclear Information System (INIS)

    Wang Xuening; Wang, T.-T.; White, John H.; Studzinski, George P.

    2007-01-01

    Induction of terminal differentiation of neoplastic cells offers potential for a novel approach to cancer therapy. One of the agents being investigated for this purpose in preclinical studies is 1,25-dihydroxyvitamin D 3 (1,25D), which can convert myeloid leukemia cells into normal monocyte-like cells, but the molecular mechanisms underlying this process are not fully understood. Here, we report that 1,25D upregulates the expression of hKSR-2, a new member of a small family of proteins that exhibit evolutionarily conserved function of potentiating ras signaling. The upregulation of hKSR-2 is direct, as it occurs in the presence of cycloheximide, and occurs primarily at the transcriptional level, via activation of vitamin D receptor, which acts as a ligand-activated transcription factor. Two VDRE-type motifs identified in the hKSR-2 gene bind VDR-RXR alpha heterodimers present in nuclear extracts of 1,25D-treated HL60 cells, and chromatin immunoprecipitation assays show that these VDRE motifs bind VDR in 1,25D-dependent manner in intact cells, coincident with the recruitment of RNA polymerase II to these motifs. Treatment of the cells with siRNA to hKSR-2 reduced the proportion of the most highly differentiated cells in 1,25D-treated cultures. These results demonstrate that hKSR-2 is a direct target of 1,25D in HL60 cells, and is required for optimal monocytic differentiation

  17. 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.

  18. 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

  19. Separate base usages of genes located on the leading and lagging strands in Chlamydia muridarum revealed by the Z curve method

    Directory of Open Access Journals (Sweden)

    Yu Xiu-Juan

    2007-10-01

    Full Text Available Abstract Background The nucleotide compositional asymmetry between the leading and lagging strands in bacterial genomes has been the subject of intensive study in the past few years. It is interesting to mention that almost all bacterial genomes exhibit the same kind of base asymmetry. This work aims to investigate the strand biases in Chlamydia muridarum genome and show the potential of the Z curve method for quantitatively differentiating genes on the leading and lagging strands. Results The occurrence frequencies of bases of protein-coding genes in C. muridarum genome were analyzed by the Z curve method. It was found that genes located on the two strands of replication have distinct base usages in C. muridarum genome. According to their positions in the 9-D space spanned by the variables u1 – u9 of the Z curve method, K-means clustering algorithm can assign about 94% of genes to the correct strands, which is a few percent higher than those correctly classified by K-means based on the RSCU. The base usage and codon usage analyses show that genes on the leading strand have more G than C and more T than A, particularly at the third codon position. For genes on the lagging strand the biases is reverse. The y component of the Z curves for the complete chromosome sequences show that the excess of G over C and T over A are more remarkable in C. muridarum genome than in other bacterial genomes without separating base and/or codon usages. Furthermore, for the genomes of Borrelia burgdorferi, Treponema pallidum, Chlamydia muridarum and Chlamydia trachomatis, in which distinct base and/or codon usages have been observed, closer phylogenetic distance is found compared with other bacterial genomes. Conclusion The nature of the strand biases of base composition in C. muridarum is similar to that in most other bacterial genomes. However, the base composition asymmetry between the leading and lagging strands in C. muridarum is more significant than that in

  20. 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.

  1. Cloning and sequencing of V genes from anti-osteosarcoma monoclonal antibodies TP-1 and TP-3: Location of lysine residues and implications for radiolabeling

    International Nuclear Information System (INIS)

    Olafsen, Tove; Bruland, Oeyvind S.; Zalutsky, Michael R.; Sandlie, Inger

    1995-01-01

    Monoclonal antibodies TP-1 and TP-3 are of potential utility for the radioimmunodiagnosis of osteosarcoma in both human and canine patients. The V genes of these antibodies were cloned and sequenced and to facilitate radiolabeling of these proteins, the location of the lysine residues within these sequences have been determined. The V-domains of TP-1 contain a total of 12 lysines, 10 in the framework region and 2 in the CDR region, while the V-domains of TP-3 contain a total of 14 lysines, 11 in the framework region and 3 in the CDR regions. Using space-filling models, the availability of each lysine residue for radiolabeling, and potential interference with antigen binding was predicted

  2. Cloning and sequencing of V genes from anti-osteosarcoma monoclonal antibodies TP-1 and TP-3: Location of lysine residues and implications for radiolabeling

    Energy Technology Data Exchange (ETDEWEB)

    Olafsen, Tove; Bruland, Oeyvind S.; Zalutsky, Michael R.; Sandlie, Inger

    1995-08-01

    Monoclonal antibodies TP-1 and TP-3 are of potential utility for the radioimmunodiagnosis of osteosarcoma in both human and canine patients. The V genes of these antibodies were cloned and sequenced and to facilitate radiolabeling of these proteins, the location of the lysine residues within these sequences have been determined. The V-domains of TP-1 contain a total of 12 lysines, 10 in the framework region and 2 in the CDR region, while the V-domains of TP-3 contain a total of 14 lysines, 11 in the framework region and 3 in the CDR regions. Using space-filling models, the availability of each lysine residue for radiolabeling, and potential interference with antigen binding was predicted.

  3. 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....

  4. 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.

  5. System and method for multi-stage bypass, low operating temperature suppressor for automatic weapons

    Science.gov (United States)

    Moss, William C.; Anderson, Andrew T.

    2015-06-09

    The present disclosure relates to a suppressor for use with a weapon. The suppressor may be formed to have a body portion having a bore extending concentric with a bore axis of the weapon barrel. An opening in the bore extends at least substantially circumferentially around the bore. A flow path communicates with the opening and defines a channel for redirecting gasses flowing in the bore out from the bore, through the opening, into a rearward direction in the flow path. The flow path raises a pressure at the opening to generate a Mach disk within the bore at a location approximately coincident with the opening. The Mach disk forms as a virtual baffle to divert at least a portion of the gasses into the opening and into the flow path.

  6. 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

  7. Physical map location of the multicopy genes coding for ammonia monooxygenase and hydroxylamine oxidoreductase in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11.

    Science.gov (United States)

    Hirota, R; Yamagata, A; Kato, J; Kuroda, A; Ikeda, T; Takiguchi, N; Ohtake, H

    2000-02-01

    Pulsed-field gel electrophoresis of PmeI digests of the Nitrosomonas sp. strain ENI-11 chromosome produced four bands ranging from 1,200 to 480 kb in size. Southern hybridizations suggested that a 487-kb PmeI fragment contained two copies of the amoCAB genes, coding for ammonia monooxygenase (designated amoCAB(1) and amoCAB(2)), and three copies of the hao gene, coding for hydroxylamine oxidoreductase (hao(1), hao(2), and hao(3)). In this DNA fragment, amoCAB(1) and amoCAB(2) were about 390 kb apart, while hao(1), hao(2), and hao(3) were separated by at least about 100 kb from each other. Interestingly, hao(1) and hao(2) were located relatively close to amoCAB(1) and amoCAB(2), respectively. DNA sequence analysis revealed that hao(1) and hao(2) shared 160 identical nucleotides immediately upstream of each translation initiation codon. However, hao(3) showed only 30% nucleotide identity in the 160-bp corresponding region.

  8. 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.

  9. Microbial Regulation of p53 Tumor Suppressor.

    Directory of Open Access Journals (Sweden)

    Alexander I Zaika

    2015-09-01

    Full Text Available p53 tumor suppressor has been identified as a protein interacting with the large T antigen produced by simian vacuolating virus 40 (SV40. Subsequent research on p53 inhibition by SV40 and other tumor viruses has not only helped to gain a better understanding of viral biology, but also shaped our knowledge of human tumorigenesis. Recent studies have found, however, that inhibition of p53 is not strictly in the realm of viruses. Some bacterial pathogens also actively inhibit p53 protein and induce its degradation, resulting in alteration of cellular stress responses. This phenomenon was initially characterized in gastric epithelial cells infected with Helicobacter pylori, a bacterial pathogen that commonly infects the human stomach and is strongly linked to gastric cancer. Besides H. pylori, a number of other bacterial species were recently discovered to inhibit p53. These findings provide novel insights into host-bacteria interactions and tumorigenesis associated with bacterial infections.

  10. 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)

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

    Science.gov (United States)

    1996-12-01

    water containing anesthetic (MS-222, 50 mg/liter) was continuously pumped into the branchial chamber. A 1.5 cm diameter hose with a flow rate of...included reducing the diameter of the hose entering the branchial chamber to 4 mm and reducing the water flow through the hose to 0.2 ml/min. Due to the

  12. Intellectual disability, oncogenes and tumour suppressor genes: the ...

    Indian Academy of Sciences (India)

    Identifying pathogenic copy number variations (CNV) involved in genomic disorders ... pathogenicity in the diagnosis of patients with intellectual disability, the ... tein has an essential role in the developing nervous system for the correct timing ...

  13. Locative media

    CERN Document Server

    Wilken, Rowan

    2014-01-01

    Not only is locative media one of the fastest growing areas in digital technology, but questions of location and location-awareness are increasingly central to our contemporary engagements with online and mobile media, and indeed media and culture generally. This volume is a comprehensive account of the various location-based technologies, services, applications, and cultures, as media, with an aim to identify, inventory, explore, and critique their cultural, economic, political, social, and policy dimensions internationally. In particular, the collection is organized around the perception that the growth of locative media gives rise to a number of crucial questions concerning the areas of culture, economy, and policy.

  14. 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

  15. Genetically based location from triploid populations and gene ontology of a 3.3-mb genome region linked to Alternaria brown spot resistance in citrus reveal clusters of resistance genes.

    Directory of Open Access Journals (Sweden)

    José Cuenca

    Full Text Available Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR to map a genome region linked to Alternaria brown spot (ABS resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids.

  16. Genetically based location from triploid populations and gene ontology of a 3.3-mb genome region linked to Alternaria brown spot resistance in citrus reveal clusters of resistance genes.

    Science.gov (United States)

    Cuenca, José; Aleza, Pablo; Vicent, Antonio; Brunel, Dominique; Ollitrault, Patrick; Navarro, Luis

    2013-01-01

    Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR) to map a genome region linked to Alternaria brown spot (ABS) resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. Location, location, location: Extracting location value from house prices

    OpenAIRE

    Kolbe, Jens; Schulz, Rainer; Wersing, Martin; Werwatz, Axel

    2012-01-01

    The price for a single-family house depends both on the characteristics of the building and on its location. We propose a novel semiparametric method to extract location values from house prices. After splitting house prices into building and land components, location values are estimated with adaptive weight smoothing. The adaptive estimator requires neither strong smoothness assumptions nor local symmetry. We apply the method to house transactions from Berlin, Germany. The estimated surface...

  2. The SlZRT1 Gene Encodes a Plasma Membrane-Located ZIP (Zrt-, Irt-Like Protein Transporter in the Ectomycorrhizal Fungus Suillus luteus

    Directory of Open Access Journals (Sweden)

    Laura Coninx

    2017-11-01

    Full Text Available Zinc (Zn is an essential micronutrient but may become toxic when present in excess. In Zn-contaminated environments, trees can be protected from Zn toxicity by their root-associated micro-organisms, in particular ectomycorrhizal fungi. The mechanisms of cellular Zn homeostasis in ectomycorrhizal fungi and their contribution to the host tree’s Zn status are however not yet fully understood. The aim of this study was to identify and characterize transporters involved in Zn uptake in the ectomycorrhizal fungus Suillus luteus, a cosmopolitan pine mycobiont. Zn uptake in fungi is known to be predominantly governed by members of the ZIP (Zrt/IrtT-like protein family of Zn transporters. Four ZIP transporter encoding genes were identified in the S. luteus genome. By in silico and phylogenetic analysis, one of these proteins, SlZRT1, was predicted to be a plasma membrane located Zn importer. Heterologous expression in yeast confirmed the predicted function and localization of the protein. A gene expression analysis via RT-qPCR was performed in S. luteus to establish whether SlZRT1 expression is affected by external Zn concentrations. SlZRT1 transcripts accumulated almost immediately, though transiently upon growth in the absence of Zn. Exposure to elevated concentrations of Zn resulted in a significant reduction of SlZRT1 transcripts within the first hour after initiation of the exposure. Altogether, the data support a role as cellular Zn importer for SlZRT1 and indicate a key role in cellular Zn uptake of S. luteus. Further research is needed to understand the eventual contribution of SlZRT1 to the Zn status of the host plant.

  3. The SlZRT1 Gene Encodes a Plasma Membrane-Located ZIP (Zrt-, Irt-Like Protein) Transporter in the Ectomycorrhizal Fungus Suillus luteus.

    Science.gov (United States)

    Coninx, Laura; Thoonen, Anneleen; Slenders, Eli; Morin, Emmanuelle; Arnauts, Natascha; Op De Beeck, Michiel; Kohler, Annegret; Ruytinx, Joske; Colpaert, Jan V

    2017-01-01

    Zinc (Zn) is an essential micronutrient but may become toxic when present in excess. In Zn-contaminated environments, trees can be protected from Zn toxicity by their root-associated micro-organisms, in particular ectomycorrhizal fungi. The mechanisms of cellular Zn homeostasis in ectomycorrhizal fungi and their contribution to the host tree's Zn status are however not yet fully understood. The aim of this study was to identify and characterize transporters involved in Zn uptake in the ectomycorrhizal fungus Suillus luteus , a cosmopolitan pine mycobiont. Zn uptake in fungi is known to be predominantly governed by members of the ZIP (Zrt/IrtT-like protein) family of Zn transporters. Four ZIP transporter encoding genes were identified in the S. luteus genome. By in silico and phylogenetic analysis, one of these proteins, SlZRT1, was predicted to be a plasma membrane located Zn importer. Heterologous expression in yeast confirmed the predicted function and localization of the protein. A gene expression analysis via RT-qPCR was performed in S. luteus to establish whether SlZRT1 expression is affected by external Zn concentrations. SlZRT1 transcripts accumulated almost immediately, though transiently upon growth in the absence of Zn. Exposure to elevated concentrations of Zn resulted in a significant reduction of SlZRT1 transcripts within the first hour after initiation of the exposure. Altogether, the data support a role as cellular Zn importer for SlZRT1 and indicate a key role in cellular Zn uptake of S. luteus . Further research is needed to understand the eventual contribution of SlZRT1 to the Zn status of the host plant.

  4. Subcellular location of Arabidopsis thaliana subfamily a1 β-galactosidases and developmental regulation of transcript levels of their coding genes.

    Science.gov (United States)

    Moneo-Sánchez, María; Izquierdo, Lucía; Martín, Ignacio; Labrador, Emilia; Dopico, Berta

    2016-12-01

    The aim of this work is to gain insight into the six members of the a1 subfamily of the β-galactosidases (BGAL) from Arabidopsis thaliana. First, the subcellular location of all these six BGAL proteins from a1 subfamily has been established in the cell wall by the construction of transgenic plants producing the enhanced green fluorescent protein (eGFP) fused to the BGAL proteins. BGAL12 is also located in the endoplasmic reticulum. Our study of the AtBGAL transcript accumulation along plant development indicated that all AtBGAL transcript appeared in initial stages of development, both dark- and light-grown seedlings, being AtBGAL1, AtBGAL2 and AtBGAL3 transcripts the predominant ones in the latter condition, mainly in the aerial part and with levels decreasing with age. The high accumulation of transcript of AtBGAL4 in basal internodes and in leaves at the end of development, and their strong increase after treatment both with BL and H 3 BO 3 point to an involvement of BGAL4 in cell wall changes leading to the cease of elongation and increased rigidity. The changes of AtBGAL transcript accumulation in relation to different stages and conditions of plant development, suggest that each of the different gene products have a plant-specific function and provides support for the proposed function of the subfamily a1 BGAL in plant cell wall remodelling for cell expansion or for cell response to stress conditions. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. Library Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Carnegie Library of Pittsburgh locations including address, coordinates, phone number, square footage, and standard operating hours. The map below does not display...

  12. Genome-Wide Analyses of the NAC Transcription Factor Gene Family in Pepper (Capsicum annuum L.: Chromosome Location, Phylogeny, Structure, Expression Patterns, Cis-Elements in the Promoter, and Interaction Network

    Directory of Open Access Journals (Sweden)

    Weiping Diao

    2018-03-01

    Full Text Available The NAM, ATAF1/2, and CUC2 (NAC transcription factors form a large plant-specific gene family, which is involved in the regulation of tissue development in response to biotic and abiotic stress. To date, there have been no comprehensive studies investigating chromosomal location, gene structure, gene phylogeny, conserved motifs, or gene expression of NAC in pepper (Capsicum annuum L.. The recent release of the complete genome sequence of pepper allowed us to perform a genome-wide investigation of Capsicum annuum L. NAC (CaNAC proteins. In the present study, a comprehensive analysis of the CaNAC gene family in pepper was performed, and a total of 104 CaNAC genes were identified. Genome mapping analysis revealed that CaNAC genes were enriched on four chromosomes (chromosomes 1, 2, 3, and 6. In addition, phylogenetic analysis of the NAC domains from pepper, potato, Arabidopsis, and rice showed that CaNAC genes could be clustered into three groups (I, II, and III. Group III, which contained 24 CaNAC genes, was exclusive to the Solanaceae plant family. Gene structure and protein motif analyses showed that these genes were relatively conserved within each subgroup. The number of introns in CaNAC genes varied from 0 to 8, with 83 (78.9% of CaNAC genes containing two or less introns. Promoter analysis confirmed that CaNAC genes are involved in pepper growth, development, and biotic or abiotic stress responses. Further, the expression of 22 selected CaNAC genes in response to seven different biotic and abiotic stresses [salt, heat shock, drought, Phytophthora capsici, abscisic acid, salicylic acid (SA, and methyl jasmonate (MeJA] was evaluated by quantitative RT-PCR to determine their stress-related expression patterns. Several putative stress-responsive CaNAC genes, including CaNAC72 and CaNAC27, which are orthologs of the known stress-responsive Arabidopsis gene ANAC055 and potato gene StNAC30, respectively, were highly regulated by treatment with

  13. 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

  14. miR-132 and miR-212 are increased in pancreatic cancer and target the retinoblastoma tumor suppressor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong-Kook [College of Pharmacy, Ohio State University, Columbus, OH 43210 (United States); Henry, Jon C. [Department of Surgery, Ohio State University, Columbus, OH 43210 (United States); Jiang, Jinmai [College of Pharmacy, Ohio State University, Columbus, OH 43210 (United States); Esau, Christine [Regulus Therapeutics, Carlsbad, CA (United States); Gusev, Yuriy [Lombardi Cancer Center, Georgetown University, Washington, DC (United States); Lerner, Megan R. [Veterans Affairs Medical Center, Oklahoma City, OK (United States); Postier, Russell G. [Department of Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Brackett, Daniel J. [Veterans Affairs Medical Center, Oklahoma City, OK (United States); Schmittgen, Thomas D., E-mail: Schmittgen.2@osu.edu [College of Pharmacy, Ohio State University, Columbus, OH 43210 (United States)

    2011-03-25

    Research highlights: {yields} The expression of miR-132 and miR-212 are significantly increased in pancreatic cancer. {yields} miR-132 and miR-212 target the tumor suppressor pRb, resulting in enhanced proliferation. {yields} miR-132 and miR-212 expression is increased by a {beta}2 adrenergic receptor agonist, suggesting a novel mechanism for pancreatic cancer progression. -- Abstract: Numerous microRNAs (miRNAs) are reported as differentially expressed in cancer, however the consequence of miRNA deregulation in cancer is unknown for many miRNAs. We report that two miRNAs located on chromosome 17p13, miR-132 and miR-212, are over-expressed in pancreatic adenocarcinoma (PDAC) tissues. Both miRNAs are predicted to target the retinoblastoma tumor suppressor, Rb1. Validation of this interaction was confirmed by luciferase reporter assay and western blot in a pancreatic cancer cell line transfected with pre-miR-212 and pre-miR-132 oligos. Cell proliferation was enhanced in Panc-1 cells transfected with pre-miR-132/-212 oligos. Conversely, antisense oligos to miR-132/-212 reduced cell proliferation and caused a G{sub 2}/M cell cycle arrest. The mRNA of a number of E2F transcriptional targets were increased in cells over expressing miR-132/-212. Exposing Panc-1 cells to the {beta}2 adrenergic receptor agonist, terbutaline, increased the miR-132 and miR-212 expression by 2- to 4-fold. We report that over-expression of miR-132 and miR-212 result in reduced pRb protein in pancreatic cancer cells and that the increase in cell proliferation from over-expression of these miRNAs is likely due to increased expression of several E2F target genes. The {beta}2 adrenergic pathway may play an important role in this novel mechanism.

  15. miR-132 and miR-212 are increased in pancreatic cancer and target the retinoblastoma tumor suppressor

    International Nuclear Information System (INIS)

    Park, Jong-Kook; Henry, Jon C.; Jiang, Jinmai; Esau, Christine; Gusev, Yuriy; Lerner, Megan R.; Postier, Russell G.; Brackett, Daniel J.; Schmittgen, Thomas D.

    2011-01-01

    Research highlights: → The expression of miR-132 and miR-212 are significantly increased in pancreatic cancer. → miR-132 and miR-212 target the tumor suppressor pRb, resulting in enhanced proliferation. → miR-132 and miR-212 expression is increased by a β2 adrenergic receptor agonist, suggesting a novel mechanism for pancreatic cancer progression. -- Abstract: Numerous microRNAs (miRNAs) are reported as differentially expressed in cancer, however the consequence of miRNA deregulation in cancer is unknown for many miRNAs. We report that two miRNAs located on chromosome 17p13, miR-132 and miR-212, are over-expressed in pancreatic adenocarcinoma (PDAC) tissues. Both miRNAs are predicted to target the retinoblastoma tumor suppressor, Rb1. Validation of this interaction was confirmed by luciferase reporter assay and western blot in a pancreatic cancer cell line transfected with pre-miR-212 and pre-miR-132 oligos. Cell proliferation was enhanced in Panc-1 cells transfected with pre-miR-132/-212 oligos. Conversely, antisense oligos to miR-132/-212 reduced cell proliferation and caused a G 2 /M cell cycle arrest. The mRNA of a number of E2F transcriptional targets were increased in cells over expressing miR-132/-212. Exposing Panc-1 cells to the β2 adrenergic receptor agonist, terbutaline, increased the miR-132 and miR-212 expression by 2- to 4-fold. We report that over-expression of miR-132 and miR-212 result in reduced pRb protein in pancreatic cancer cells and that the increase in cell proliferation from over-expression of these miRNAs is likely due to increased expression of several E2F target genes. The β2 adrenergic pathway may play an important role in this novel mechanism.

  16. Tumor suppressor p53 biology, its role in radioresponse and the analysis of p53 mutation/expression among Filipino breast cancers

    International Nuclear Information System (INIS)

    Deocaris, Custer C.

    2004-01-01

    Ionizing radiation remains one of the most effective tools for the treatment of breast cancer. It combines properties of a potent DNA-damaging agent and high degree of spatial specificity to the target tissue. Nonetheless, there remain considerable differences in the outcome for treatment of tumors of differing histological type treated by radiotherapy. The identification of predictive indicators of radiosensitivity is crucial for selecting patients suited for preoperative radiotherapy as well as those unwarranted for postoperative treatments. To improve prognostication, numerous genes involved in the breast carcinogenesis have been studied and thus far over the last decade several multi-center researches converge on the role of tumor suppressor p53 in tumor biology. The p53 gene is located on the short arm of chromosome 17 and encodes a 53-kd nuclear protein, p-53, also referred to as 'the guardian of the genome', it orchestrates multiple cellular processes such as cell growth control, DNA repair and programmed cell death. During radiotherapy, genotoxic damage induces p53 overexpression in order to control the rate of proliferating damaged cells, repair damage or induce the apoptotic pathway. Its molecular inactivation in a tumor cell, typically by a point mutation, leads to chemo/radio resistance due to the inability of the molecule to trigger p53-dependent programmed cell death

  17. 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.

  18. 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.

  19. Hilar granule cells of the mouse dentate gyrus: effects of age, septotemporal location, strain, and selective deletion of the proapoptotic gene BAX.

    Science.gov (United States)

    Bermudez-Hernandez, Keria; Lu, Yi-Ling; Moretto, Jillian; Jain, Swati; LaFrancois, John J; Duffy, Aine M; Scharfman, Helen E

    2017-09-01

    The dentate gyrus (DG) principal cells are glutamatergic granule cells (GCs), and they are located in a compact cell layer. However, GCs are also present in the adjacent hilar region, but have been described in only a few studies. Therefore, we used the transcription factor prospero homeobox 1 (Prox1) to quantify GCs at postnatal day (PND) 16, 30, and 60 in a common mouse strain, C57BL/6J mice. At PND16, there was a large population of Prox1-immunoreactive (ir) hilar cells, with more in the septal than temporal hippocampus. At PND30 and 60, the size of the hilar Prox1-ir cell population was reduced. Similar numbers of hilar Prox1-expressing cells were observed in PND30 and 60 Swiss Webster mice. Prox1 is usually considered to be a marker of postmitotic GCs. However, many Prox1-ir hilar cells, especially at PND16, were not double-labeled with NeuN, a marker typically found in mature neurons. Most hilar Prox1-positive cells at PND16 co-expressed doublecortin (DCX) and calretinin, markers of immature GCs. Double-labeling with a marker of actively dividing cells, Ki67, was not detected. These results suggest that, surprisingly, a large population of cells in the hilus at PND16 are immature GCs (Type 2b and Type 3 cells). We also asked whether hilar Prox1-ir cell numbers are modifiable. To examine this issue, we conditionally deleted the proapoptotic gene BAX in Nestin-expressing cells at a time when there are numerous immature GCs in the hilus, PND2-8. When these mice were examined at PND60, the numbers of Prox1-ir hilar cells were significantly increased compared to control mice. However, deletion of BAX did not appear to change the proportion that co-expressed NeuN, suggesting that the size of the hilar Prox1-expressing population is modifiable. However, deleting BAX, a major developmental disruption, does not appear to change the proportion that ultimately becomes neurons.

  20. Transforming capacity of two novel genes JS-1 and JS-2 located in chromosome 5p and their overexpression in human esophageal squamous cell carcinoma.

    Science.gov (United States)

    Fatima, Sarwat; Chui, Chung H; Tang, Wing K; Hui, Kin S; Au, Ho W; Li, Wing Y; Wong, Mei M; Cheung, Filly; Tsao, S W; Lam, King Y; Beh, Philip S L; Wong, John; Law, Simon; Srivastava, Gopesh; Ho, Kwok P; Chan, Albert S C; Tang, Johnny C O

    2006-01-01

    Esophageal squamous cell carcinoma (ESCC) has a high mortality rate and geographic differences in incidence. Previous studies of comparative genomic hybridization (CGH) showed that chromosomal 5p is frequently amplified in cell lines and primary ESCC of Hong Kong Chinese origin. In this report, attempt was made to study two novel genes, named as JS-1 and JS-2, which are located in chromosome 5p15.2 and are 5' upstream to delta catenin for their roles in molecular pathogenesis of ESCC. Eleven cell lines, 27 primary ESCC cases and multiple human tissue cDNA panels (MTC) of digestive system were studied for the expression level of JS-1 and JS-2 by RT-PCR. The full-length cDNA sequences of JS-1 and JS-2 were determined from a non-tumor esophageal epithelial cell line by 3' and 5' rapid amplification of cDNA ends (RACE). The transforming capacity of JS-1 and JS-2 was also investigated by transfecting NIH 3T3 cells with the expression vector pcDNA3.1(-) cloned with the full coding sequences and it was followed by the study of foci formation of the transfected cells under confluence growth and the anchorage-independent growth in soft agar. Forty-five percent (5/11) and 18% (2/11) of the ESCC cell lines showed overexpression of JS-1 and JS-2 respectively, while 55% (15/27) and 14% (3/22) primary ESCC cases showed overexpression of JS-1 and JS-2 respectively. JS-1 overexpression was most common in patients with stage II ESCC (6/27; 22%) whereas JS-2 was only overexpressed in a dysplastic lesion (1/22; 4%) and stage III tumors (2/22; 9%). The expression levels of JS-1 and JS-2 are both low in normal esophageal tissues. Overexpression of JS-1 in NIH 3T3 cells caused foci formation in confluence growth and colony formation in soft agar but not for JS-2. A high grade sarcoma was formed in the athymic nude mice when NIH 3T3 cells overexpressing JS-1 were injected subcutaneously. Our results thus indicate that the frequent overexpression of JS-1 in ESCC and its transforming

  1. Association analysis of the chromosome 4p-located G protein-coupled receptor 78 (GPR78) gene in bipolar affective disorder and schizophrenia.

    Science.gov (United States)

    Underwood, S L; Christoforou, A; Thomson, P A; Wray, N R; Tenesa, A; Whittaker, J; Adams, R A; Le Hellard, S; Morris, S W; Blackwood, D H R; Muir, W J; Porteous, D J; Evans, K L

    2006-04-01

    The orphan G protein-coupled receptor 78 (GPR78) gene lies within a region of chromosome 4p where we have previously shown linkage to bipolar affective disorder (BPAD) in a large Scottish family. GPR78 was screened for single-nucleotide polymorphisms (SNPs) and a linkage disequilibrium map was constructed. Six tagging SNPs were selected and tested for association on a sample of 377 BPAD, 392 schizophrenia (SCZ) and 470 control individuals. Using standard chi(2) statistics and a backwards logistic regression approach to adjust for the effect of sex, SNP rs1282, located approximately 3 kb upstream of the coding region, was identified as a potentially important variant in SCZ (chi(2) P=0.044; LRT P=0.065). When the analysis was restricted to females, the strength of association increased to an uncorrected allele P-value of 0.015 (odds ratios (OR)=1.688, 95% confidence intervals (CI): 1.104-2.581) and uncorrected genotype P-value of 0.015 (OR=5.991, 95% CI: 1.545-23.232). Under the recessive model, the genotype P-value improved further to 0.005 (OR=5.618, 95% CI: 1.460-21.617) and remained significant after correcting for multiple testing (P=0.017). No single-marker association was detected in the SCZ males, in the BPAD individuals or with any other SNP. Haplotype analysis of the case-control samples revealed several global and individual haplotypes, with P-values <0.05, all but one of which contained SNP rs1282. After correcting for multiple testing, two haplotypes remained significant in both the female BPAD individuals (P=0.038 and 0.032) and in the full sample of affected female individuals (P=0.044 and 0.033). Our results provide preliminary evidence for the involvement of GPR78 in susceptibility to BPAD and SCZ in the Scottish population. Molecular Psychiatry (2006) 11, 384-394. doi:10.1038/sj.mp.4001786; published online 3 January 2006.

  2. 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.

  3. Somatic mutations in the transcriptional corepressor gene BCORL1 in adult acute myelogenous leukemia.

    Science.gov (United States)

    Li, Meng; Collins, Roxane; Jiao, Yuchen; Ouillette, Peter; Bixby, Dale; Erba, Harry; Vogelstein, Bert; Kinzler, Kenneth W; Papadopoulos, Nickolas; Malek, Sami N

    2011-11-24

    To further our understanding of the genetic basis of acute myelogenous leukemia (AML), we determined the coding exon sequences of ∼ 18 000 protein-encoding genes in 8 patients with secondary AML. Here we report the discovery of novel somatic mutations in the transcriptional corepressor gene BCORL1 that is located on the X-chromosome. Analysis of BCORL1 in an unselected cohort of 173 AML patients identified a total of 10 mutated cases (6%) with BCORL1 mutations, whereas analysis of 19 AML cell lines uncovered 4 (21%) BCORL1 mutated cell lines. The majority (87%) of the mutations in BCORL1 were predicted to inactivate the gene product as a result of nonsense mutations, splice site mutation, or out-of-frame insertions or deletions. These results indicate that BCORL1 by genetic criteria is a novel candidate tumor suppressor gene, joining the growing list of genes recurrently mutated in AML.

  4. 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

  5. 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

  6. [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.

  7. Effect of genomic location on horizontal transfer of a recombinant gene cassette between Pseudomonas strains in the rhizosphere and spermosphere of barley seedlings

    DEFF Research Database (Denmark)

    Sengelov, G.; Kristensen, K. J.; Sørensen, Anders Morten Hay

    2001-01-01

    , horizontal transfer of a recombinant gene cassette inserted into the chromosome of a Pseudomonas strutzeri strain, into a mobilizable plasmid (pAGM42), and into a conjugative plasmid (pKJK5) isolated from barley rhizosphere was investigated. Horizontal transfer efficiencies of the gene cassette inserted...... efficiencies were up to 4.36 x 10(-3) transconjugants/(donors x recipients)(1/2). Transfer of chromosomal encoded genes could not be detected in the microcosms by conjugation or transformation. However, transformation did occur by using the same bacterial strains under laboratory conditions. The rhizosphere...

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  13. 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

  14. Multi-location gram-positive and gram-negative bacterial protein subcellular localization using gene ontology and multi-label classifier ensemble.

    Science.gov (United States)

    Wang, Xiao; Zhang, Jun; Li, Guo-Zheng

    2015-01-01

    It has become a very important and full of challenge task to predict bacterial protein subcellular locations using computational methods. Although there exist a lot of prediction methods for bacterial proteins, the majority of these methods can only deal with single-location proteins. But unfortunately many multi-location proteins are located in the bacterial cells. Moreover, multi-location proteins have special biological functions capable of helping the development of new drugs. So it is necessary to develop new computational methods for accurately predicting subcellular locations of multi-location bacterial proteins. In this article, two efficient multi-label predictors, Gpos-ECC-mPLoc and Gneg-ECC-mPLoc, are developed to predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. The two multi-label predictors construct the GO vectors by using the GO terms of homologous proteins of query proteins and then adopt a powerful multi-label ensemble classifier to make the final multi-label prediction. The two multi-label predictors have the following advantages: (1) they improve the prediction performance of multi-label proteins by taking the correlations among different labels into account; (2) they ensemble multiple CC classifiers and further generate better prediction results by ensemble learning; and (3) they construct the GO vectors by using the frequency of occurrences of GO terms in the typical homologous set instead of using 0/1 values. Experimental results show that Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently improve prediction accuracy of subcellular localization of multi-location gram-positive and gram-negative bacterial proteins respectively. The online web servers for Gpos-ECC-mPLoc and Gneg-ECC-mPLoc predictors are freely accessible

  15. 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 ...

  16. 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...

  17. 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

  18. Structural and functional organization of the HF.10 human zinc finger gene (ZNF35) located on chromosome 3p21-p22

    DEFF Research Database (Denmark)

    Lanfrancone, L; Pengue, G; Pandolfi, P P

    1992-01-01

    We report the structural and functional characterization of the HF.10 zinc finger gene (ZNF35) in normal human cells, as well as a processed pseudogene. The HF.10 gene spans about 13 kb and it is interrupted by three introns. All 11 zinc finger DNA-binding domains are contiguously encoded within...... and partial nucleotide sequencing of the HF.10 pseudogene indicated that it has arisen by retroposition of spliced HF.10 mRNA. In situ hybridization experiments revealed that both the functional locus and the pseudogene map to chromosome 3p21p22, a region that is frequently deleted in small cell lung...... and renal carcinomas. Hybridization of the HF.10 gene and the HF.10 pseudogene DNA probes to metaphases from a small cell lung carcinoma cell line with the 3p deletion revealed that both loci are part of the deleted chromosome region....

  19. Chromosomal locations and modes of action of genes of the retinoid (vitamin A) system support their involvement in the etiology of schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, A.B. [Columbia Univ. School of Public Health, New York, NY (United States)

    1995-08-14

    Vitamin A (retinoid), an essential nutrient for fetal and subsequent mammalian development, is involved in gene expression, cell differentiation, proliferation, migration, and death. Retinoic acid (RA) the morphogenic derivative of vitamin A is highly teratogenic. In humans retinoid excess or deficit can result in brain anomalies and psychosis. This review discusses chromosomal loci of genes that control the retinoid cascade in relation to some candidate genes in schizophrenia. The paper relates the knowledge about the transport, delivery, and action of retinoids to what is presently known about the pathology of schizophrenia, with particular reference to the dopamine hypothesis, neurotransmitters, the glutamate hypothesis, neurotransmitters, the glutamate hypothesis, retinitis pigmentosa, dermatologic disorders, and craniofacial anomalies. 201 refs., 1 tab.

  20. Identification of a novel first exon in the human dystrophin gene and of a new promoter located more than 500 kb upstream of the nearest known promoter

    Energy Technology Data Exchange (ETDEWEB)

    Yanagawa, H.; Nishio, H.; Takeshima, Y. [Kobe Univ. School of Medicine (Japan)] [and others

    1994-09-01

    The dystrophin gene, which is muted in patients with Duchenne and Becker muscular dystrophies, is the largest known human gene. Five alternative promoters have been characterized until now. Here we show that a novel dystrophin isoform with a different first exon can be produced through transcription initiation at a previously-unidentified alternative promoter. The case study presented is that of patient with Duchenne muscular dystrophy who had a deletion extending from 5{prime} end of the dystrophin gene to exon 2, including all promoters previously mapped in the 5{prime} part of the gene. Transcripts from lymphoblastoid cells were found to contain sequences corresponding to exon 3, indicating the presence of new promoter upstream of this exon. The nucleotide sequence of amplified cDNA corresponding to the 5{prime} end of the new transcript indicated that the 5{prime} end of exon 3 was extended by 9 codons, only the last (most 3{prime}) of which codes for methionine. The genomic nucleotide sequence upstream from the new exon, as determined using inverse polymerase chain reaction, revealed the presence of sequences similar to a TATA box, an octamer motif and an MEF-2 element. The identified promoter/exon did not map to intron 2, as might have been expected, but to a position more than 500 kb upstream of the most 5{prime} of the previously-identified promoters, thereby adding 500 kb to the dystrophin gene. The sequence of part of the new promoter region is very similar to that of certain medium reiteration frequency repetitive sequences. These findings may help us understand the molecular evolution of the dystrophin gene.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Locating a Prostate Cancer Susceptibility Gene on the X Chromosome by Linkage Disequilibrium Mapping Using Three Founder Populations in Quebec and Switzerland

    Science.gov (United States)

    2006-09-01

    Gordon PH, Wang Q, Puisieux, A, Foulkes WD and Trifiro M. Polymorphisms and HNPCC: PMS2 -MLH1 protein interactions diminished by ‘single nucleotide...and PMS2 responsible for hereditary nonpolyposis colorectal cancer (HNPCC). Genes Chromosomes Cancer, 44 (2): 123-38, 2005. 120. Soravia C

  7. A Molecular-Cytogenetic Method for Locating Genes to Pericentromeric Regions Facilitates a Genome-Wide Comparison of Syntency Between the Centrometric Regions of Wheat and Rice

    Science.gov (United States)

    Centromeres, because of their repeat structure and lack of sequence conservation, are difficult to assemble and compare across organisms. It was recently discovered that rice centromeres often contain genes. This suggested a method for studying centromere homologies between wheat and rice chromosome...

  8. Clustering, haplotype diversity and locations of MIC-3: a unique root-specific defense-related gene family in upland cotton (Gossypium hirsutum L.)

    Science.gov (United States)

    MIC-3-related genes of cotton (Gossypium spp.) were identified and shown to have root-specific expression, associated with pathogen defense-related function and specifically increased expression in root-knot nematode (RKN) resistant plants after nematode infection. Here we cloned and sequenced MIC-...

  9. 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

  10. 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...

  11. 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

  12. A new tetracycline efflux gene, tet(40), is located in tandem with tet(O/32/O) in a human gut firmicute bacterium and in metagenomic library clones.

    Science.gov (United States)

    Kazimierczak, Katarzyna A; Rincon, Marco T; Patterson, Andrea J; Martin, Jennifer C; Young, Pauline; Flint, Harry J; Scott, Karen P

    2008-11-01

    The bacterium Clostridium saccharolyticum K10, isolated from a fecal sample obtained from a healthy donor who had received long-term tetracycline therapy, was found to carry three tetracycline resistance genes: tet(W) and the mosaic tet(O/32/O), both conferring ribosome protection-type resistance, and a novel, closely linked efflux-type resistance gene designated tet(40). tet(40) encodes a predicted membrane-associated protein with 42% amino acid identity to tetA(P). Tetracycline did not accumulate in Escherichia coli cells expressing the Tet(40) efflux protein, and resistance to tetracycline was reduced when cells were incubated with an efflux pump inhibitor. E. coli cells carrying tet(40) had a 50% inhibitory concentration of tetracycline of 60 microg/ml. Analysis of a transconjugant from a mating between donor strain C. saccharolyticum K10 and the recipient human gut commensal bacterium Roseburia inulinivorans suggested that tet(O/32/O) and tet(40) were cotransferred on a mobile element. Sequence analysis of a 37-kb insert identified on the basis of tetracycline resistance from a metagenomic fosmid library again revealed a tandem arrangement of tet(O/32/O) and tet(40), flanked by regions with homology to parts of the VanG operon previously identified in Enterococcus faecalis. At least 10 of the metagenomic inserts that carried tet(O/32/O) also carried tet(40), suggesting that tet(40), although previously undetected, may be an abundant efflux gene.

  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. 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.

  15. KF-1 ubiquitin ligase: an anxiety suppressor

    Directory of Open Access Journals (Sweden)

    Tamotsu Hashimoto-Gotoh

    2009-05-01

    Full Text Available Anxiety is an instinct that may have developed to promote adaptive survival by evading unnecessary danger. However, excessive anxiety is disruptive and can be a basic disorder of other psychiatric diseases such as depression. The KF-1, a ubiquitin ligase located to the endoplasmic reticulum (ER, may prevent excessive anxiety; kf-1−/− mice exhibit selectively elevated anxiety-like behavior against light or heights. Thus, KF-1 may degrade some target proteins, responsible for promoting anxiety, through the ER-associated degradation pathway, similar to Parkin in Parkinson's disease (PD. Parkin, another ER-ubiquitin ligase, prevents the degeneration of dopaminergic neurons by degrading the target proteins responsible for PD. Molecular phylogenetic studies have revealed that the prototype of kf-1 appeared in the very early phase of animal evolution but was lost, unlike parkin, in the lineage leading up to Drosophila. Therefore, kf-1−/− mice, be a powerful tool for elucidating the molecular mechanisms involved in emotional regulation, and for screening novel anxiolytic/antidepressant compounds.

  16. The chicken beta 2-microglobulin gene is located on a non-major histocompatibility complex microchromosome: a small, G+C-rich gene with X and Y boxes in the promoter

    DEFF Research Database (Denmark)

    Riegert, P; Andersen, R; Bumstead, N

    1996-01-01

    a similar genomic organization but smaller introns and higher G+C content than mammalian beta 2-microglobulin genes. The promoter region is particularly G+C-rich and contains, in addition to interferon regulatory elements, potential S/W, X, and Y boxes that were originally described for mammalian class II...... but not class I alpha or beta 2-microglobulin genes. There is a single chicken beta 2-microglobulin gene that has little polymorphism in the coding region. Restriction fragment length polymorphisms from Mhc homozygous lines, Mhc congenic lines, and backcross families, as well as in situ hybridization, show...

  17. Interleukin 3 gene is located on human chromosome 5 and is deleted in myeloid leukemias with a deletion of 5q

    International Nuclear Information System (INIS)

    Le Beau, M.M.; Epstein, N.D.; O'Brien, S.J.; Nienhuis, A.W.; Yang, Y.C.; Clark, S.C.; Rowley, J.D.

    1987-01-01

    The gene IL-3 encodes interleukin 3, a hematopoietic colony-stimulating factor (CSF) that is capable of supporting the proliferation of a broad range of hematopoietic cell types. By using somatic cell hybrids and in situ chromosomal hybridization, the authors localized this gene to human chromosome 5 at bands q23-31, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, IL-3 was found to be deleted in the 5q-chromosome of one patient with refractory anemia who had a del(5)(q15q33.3), of three patients with refractory anemia (two patients) or acute nonlymphocytic leukemia (ANLL) de novo who had a similar distal breakpoint [del(5)(q13q33.3)], and of a fifth patient, with therapy-related ANLL, who had a similar distal breakpoint in band q33[del(5)(q14q33.3)]. Southern blot analysis of somatic cell hybrids retaining the normal or the deleted chromosome 5 from two patients with the refractory anemia 5q- syndrome indicated that IL-3 sequences were absent from the hybrids retaining the deleted chromosome 5 but not from hybrids that had a cytologically normal chromosome 5. Thus, a small segment of chromosome 5 contains IL-3, GM-CSF, CSF-1, and FMS. The findings and earlier results indicating that GM-CSF, CSF-1, and FMS were deleted in the 5q- chromosome, suggest that loss of IL-3 or of other CSF genes may play an important role in the pathogenesis of hematologic disorders associated with a del(5q)

  18. Identification and characterization of a GDSL esterase gene located proximal to the swr quorum-sensing system of Serratia liquefaciens MG1

    DEFF Research Database (Denmark)

    Riedel, K.; Talker-Huiber, D.; Givskov, Michael Christian

    2003-01-01

    direction, designated estA, which encodes an esterase that belongs to family II of lipolytic enzymes. EstA was heterologously expressed in Escherichia coli, and the substrate specificity of the enzyme was determined in crude extracts. With the aid of zymograms visualizing EstA on polyacrylamide gels...... and by the analysis of a transcriptional fusion of the estA promoter to the promoterless lux4B genes, we showed that expression of the esterase is not regulated by the swr quorum-sensing system. An estA mutant was generated and was found to exhibit growth defects on minimal medium containing Tween 20 or Tween 80...

  19. 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.

  20. 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.

  1. Imunolocalização das proteínas dos genes supressores de tumores TP53 e p16CDKN2 no front invasivo do carcinoma epidermóide de cavidade bucal Immunolocalization of TP53 and p16CDKN2 tumour suppressor genes proteins in invasive front of oral epidermoid carcinoma

    Directory of Open Access Journals (Sweden)

    Alfredo Maurício Batista De-Paula

    2006-08-01

    vias moleculares independentes.BACKGROUND: Oral carcinogenesis is a multistep process in which genetic events lead to the disruption of the normal regulatory pathways that control basic cellular functions. Epidermoid carcinoma of oral cavity (ECOC appears as a consequence of multiple molecular events induced by the effects of several carcinogens influenced by environmental factors against a background of genetic resistance or susceptibility. Consequent genetic damage affects many chromosomes and genes, and the accumulation of these changes seems to lead to ECOC. OBJECTIVES: The aim of the present study was to assess the clinical and morphological value of p53 and p16 immunolocalization at the invasive tumor front in a representative series of 35 routinely processed ECOC. MATERIAL AND METHODS: Samples of ECOC were investigated in this study. TNM system was employed for clinical staging and the invasive front grading system was employed for morphological grading of the lesions. Immunohistochemical technique in paraffin-embedded and formalin-fixed tissues was utilized to immunolocalization of p53 and p16 proteins. Counts were performed and submitted to specific statistical treatments. RESULTS: p53 and p16 immunolocalizations were detected in 63% and 66%, respectively, of 35 carcinomas studied. No correlation was found between p53 and p16 expressions and clinico-morphological parameters statistically analyzed. No correlation was found between the relationship p53/p16 expressions. CONCLUSION: p53 and p16 immunolocalization did not influence the clinico-morphological parameters analyzed in this study and apparently do not represent a molecular basis for the biologic significance of the invasive tumor front. Lack of a strong correlation between p53 and p16 immunolocalization suggests that both could participate in biological activities in the cell cycle control by independent molecular pathways.

  2. GOASVM: a subcellular location predictor by incorporating term-frequency gene ontology into the general form of Chou's pseudo-amino acid composition.

    Science.gov (United States)

    Wan, Shibiao; Mak, Man-Wai; Kung, Sun-Yuan

    2013-04-21

    Prediction of protein subcellular localization is an important yet challenging problem. Recently, several computational methods based on Gene Ontology (GO) have been proposed to tackle this problem and have demonstrated superiority over methods based on other features. Existing GO-based methods, however, do not fully use the GO information. This paper proposes an efficient GO method called GOASVM that exploits the information from the GO term frequencies and distant homologs to represent a protein in the general form of Chou's pseudo-amino acid composition. The method first selects a subset of relevant GO terms to form a GO vector space. Then for each protein, the method uses the accession number (AC) of the protein or the ACs of its homologs to find the number of occurrences of the selected GO terms in the Gene Ontology annotation (GOA) database as a means to construct GO vectors for support vector machines (SVMs) classification. With the advantages of GO term frequencies and a new strategy to incorporate useful homologous information, GOASVM can achieve a prediction accuracy of 72.2% on a new independent test set comprising novel proteins that were added to Swiss-Prot six years later than the creation date of the training set. GOASVM and Supplementary materials are available online at http://bioinfo.eie.polyu.edu.hk/mGoaSvmServer/GOASVM.html. Copyright © 2013 Elsevier Ltd. All rights reserved.

  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. 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. 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...

  6. 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

  7. Two wheat glutathione peroxidase genes whose products are located in chloroplasts improve salt and H2O2 tolerances in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Chao-Zeng Zhai

    Full Text Available Oxidative stress caused by accumulation of reactive oxygen species (ROS is capable of damaging effects on numerous cellular components. Glutathione peroxidases (GPXs, EC 1.11.1.9 are key enzymes of the antioxidant network in plants. In this study, W69 and W106, two putative GPX genes, were obtained by de novo transcriptome sequencing of salt-treated wheat (Triticum aestivum seedlings. The purified His-tag fusion proteins of W69 and W106 reduced H2O2 and t-butyl hydroperoxide (t-BHP using glutathione (GSH or thioredoxin (Trx as an electron donor in vitro, showing their peroxidase activity toward H2O2 and toxic organic hydroperoxide. GFP fluorescence assays revealed that W69 and W106 are localized in chloroplasts. Quantitative real-time PCR (Q-RT-PCR analysis showed that two GPXs were differentially responsive to salt, drought, H2O2, or ABA. Isolation of the W69 and W106 promoters revealed some cis-acting elements responding to abiotic stresses. Overexpression of W69 and W106 conferred strong tolerance to salt, H2O2, and ABA treatment in Arabidopsis. Moreover, the expression levels of key regulator genes (SOS1, RbohD and ABI1/ABI2 involved in salt, H2O2 and ABA signaling were altered in the transgenic plants. These findings suggest that W69 and W106 not only act as scavengers of H2O2 in controlling abiotic stress responses, but also play important roles in salt and ABA signaling.

  8. 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.

  9. 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...

  10. Evidence for an association between nonsyndromic cleft lip with or without cleft palate and a gene located on the long arm of chromosome 4

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, L.E.; Healey, S.C.; Chenevix-Trench, G. [St. Louis Univ. Health Sciences Center, MO (United States)]|[Queensland Institute of Medical Research, Brisbane (Australia)

    1995-11-01

    Recent studies suggest that the familial aggregation of nonsyndromic cleft lip with or without cleft palate (CL{+-}P) is likely to be attributable to the effects of several susceptibility loci, acting in a multiplicative fashion. Two potential CL{+-}P susceptibility loci (CSL), transforming growth factor alpha (TGFA) and retinoic acid receptor (RARA), have been identified through association studies. In addition, recent evidence of linkage between CL{+-}P and two markers (D4S175 and D4S192) in the region 4q25-4q31.3 raised the possibility that a CSL, with a larger effect than either TGFA or RARA, may reside within this region of the human genome. The present analyses were undertaken to determine whether D4S175 or D4S192 is significantly associated with CL{+-}P in a sample of unrelated patients that have previously provided evidence of associations between CL{+-}P and both TGFA and RARA. The results of these analyses provide further, tentative, evidence for the presence of a CSL locus on the long arm of chromosome 4 and help to refine the location of this locus in the region of D4S175 and D4S192. 28 refs., 4 tabs.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Tumor suppressor protein SMAR1 modulates the roughness of cell surface: combined AFM and SEM study

    Directory of Open Access Journals (Sweden)

    Mamgain Hitesh

    2009-10-01

    Full Text Available Abstract Background Imaging tools such as scanning electron microscope (SEM and atomic force microscope (AFM can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK 293, human breast cancer (MCF-7 and mouse melanoma (B16F1 cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM and scanning electron microscopy (SEM. The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion Tumor suppressor

  17. Evidence for an association between non-syndromic cleft lip with or without cleft palate and a gene located on the long arm of chromosome 4

    Energy Technology Data Exchange (ETDEWEB)

    Healey, S.C.; Chenevix-Trench, G. [Queensland Institute of Medical Research, Brisbane (Australia); Mitchell, L.E. [Saint Louis Univ., MO (United States)

    1994-09-01

    Evidence of linkage has been reported for non-syndromic cleft lip with or without cleft palate (CL{+-}P) and two markers (D4S175 and D4S192) in the region 4q25-4q31.3. The linkage evidence comes from a single Caucasian pedigree with multiple cases of CL{+-}P in five generations. High-density pedigrees are, however, atypical of CL{+-}P and linkage evidence obtained from such a family may not be relevant to the majority of CL{+-}P families. We have, therefore, examined the association of CL{+-}P with both D4S175 and D4S192 in 95 unrelated CL{+-}P patients and 161 unselected controls. There was no evidence for an association between D4S175 and CL{+-}P in these data. There was, however, a significant association between D4S192 and CL{+-}P ({chi}{sup 2}{sub 4}=15.5,P=0.006), and the genotypic distribution was significantly heterogeneous between CL{+-}P patients and controls (P=0.025). Comparison of each of the four most common alleles (i.e A87, A89, A91 and A95), to all other alleles combined, indicated that A87 was significantly less common (OR=0.56,95% C.I. 0.34-0.90), and A95 was significantly more common (OR=1.88,95% C.I. 1.03-3.43) among the CL{+-}P patients than the controls. Although of only borderline significance, A89 also appeared to be more common among patients than controls (OR=1.43,95% C.I. 0.99-2.60). Hence, it appears that genetic variation at a CL{+-}P susceptibility locus (CSL) linked to D4S192 may be associated with both increased and decreased risk of CL{+-}P. In combination, A89 and A95 are significantly more common in CL{+-}P patients than in controls (OR=1.80;95% C.I. 1.24-2.60) and account for a risk ratio of 1.08 in the first degree relatives of CL{+-}P patients. These results provide further evidence for the presence of a CSL in the region 4q25-4q31.1, and indicate that the putative CSL is located closer to D4S192 than to D4S175.

  18. Leucine insertion caused by a yeast amber suppressor

    Energy Technology Data Exchange (ETDEWEB)

    Liebman, S W [Univ. of Rochester School of Medicine and Dentistry, NY; Stewart, J W; Parker, J H; Sherman, F

    1977-01-01

    The amber suppressor SUP52 can cause the production of approximately 15 to 20% of the normal amount of iso-l-cytochrome c when coupled to the amber (UAG) mutant cyc1-76. The suppressed iso-l-cytochrome c contains a residue of leucine at the position corresponding to the site of the amber codon. SUP52 also supresses another amber allele cyc1-179, but only with a low efficiency of approximately 2%. It does not appear to act at all on ochre (UAA) mutants. SUP52 was found to be on the left arm of chromosome X closely linked to the centromere.

  19. 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.

  20. 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

  1. 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.

  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. 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

  4. 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.

  5. 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.

  6. Suppressor of cytokine signaling 1 expression during LPS-induced inflammation and bone loss in rats

    Directory of Open Access Journals (Sweden)

    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.

  7. Transcriptional Inhibition of the Human Papilloma Virus Reactivates Tumor Suppressor p53 in Cervical Carcinoma Cells

    Science.gov (United States)

    Kochetkov, D. V.; Ilyinskaya, G. V.; Komarov, P. G.; Strom, E.; Agapova, L. S.; Ivanov, A. V.; Budanov, A. V.; Frolova, E. I.; Chumakov, P. M.

    2009-01-01

    Inactivation of tumor suppressor p53 accompanies the majority of human malignancies. Restoration of p53 function causes death of tumor cells and is potentially suitable for gene therapy of cancer. In cervical carcinoma, human papilloma virus (HPV) E6 facilitates proteasomal degradation of p53. Hence, a possible approach to p53 reactivation is the use of small molecules suppressing the function of viral proteins. HeLa cervical carcinoma cells (HPV-18) with a reporter construct containing the b-galactosidase gene under the control of a p53-responsive promoter were used as a test system to screen a library of small molecules for restoration of the transcriptional activity of p53. The effect of the two most active compounds was studied with cell lines differing in the state of p53-dependent signaling pathways. The compounds each specifically activated p53 in cells expressing HPV-18 and, to a lesser extent, HPV-16 and exerted no effect on control p53-negative cells or cells with the intact p53-dependent pathways. Activation of p53 in cervical carcinoma cells was accompanied by induction of p53-dependent CDKN1 (p21), inhibition of cell proliferation, and induction of apoptosis. In addition, the two compounds dramatically decreased transcription of the HPV genome, which was assumed to cause p53 reactivation. The compounds were low-toxic for normal cells and can be considered as prototypes of new anticancer drugs. PMID:17685229

  8. 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

  9. Gemfibrozil, a Lipid-lowering Drug, Induces Suppressor of Cytokine Signaling 3 in Glial Cells

    Science.gov (United States)

    Ghosh, Arunava; Pahan, Kalipada

    2012-01-01

    Glial inflammation is an important feature of several neurodegenerative disorders. Suppressor of cytokine signaling (SOCS) proteins play a crucial role in inhibiting cytokine signaling and inflammatory gene expression in various cell types, including glial cells. However, mechanisms by which SOCS genes could be up-regulated are poorly understood. This study underlines the importance of gemfibrozil, a Food and Drug Administration-approved lipid-lowering drug, in up-regulating the expression of SOCS3 in glial cells. Gemfibrozil increased the expression of Socs3 mRNA and protein in mouse astroglia and microglia in both a time- and dose-dependent manner. Interestingly, gemfibrozil induced the activation of type IA phosphatidylinositol (PI) 3-kinase and AKT. Accordingly, inhibition of PI 3-kinase and AKT by chemical inhibitors abrogated gemfibrozil-mediated up-regulation of SOCS3. Furthermore, we demonstrated that gemfibrozil induced the activation of Krüppel-like factor 4 (KLF4) via the PI 3-kinase-AKT pathway and that siRNA knockdown of KLF4 abrogated gemfibrozil-mediated up-regulation of SOCS3. Gemfibrozil also induced the recruitment of KLF4 to the distal, but not proximal, KLF4-binding site of the Socs3 promoter. This study delineates a novel property of gemfibrozil in up-regulating SOCS3 in glial cells via PI 3-kinase-AKT-mediated activation of KLF4 and suggests that gemfibrozil may find therapeutic application in neuroinflammatory and neurodegenerative disorders. PMID:22685291

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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...

  15. 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.

  16. CpG location and methylation level are crucial factors for the early detection of oral squamous cell carcinoma in brushing samples using bisulfite sequencing of a 13-gene panel.

    Science.gov (United States)

    Morandi, Luca; Gissi, Davide; Tarsitano, Achille; Asioli, Sofia; Gabusi, Andrea; Marchetti, Claudio; Montebugnoli, Lucio; Foschini, Maria Pia

    2017-01-01

    Oral squamous cell carcinoma (OSCC) is usually diagnosed at an advanced stage and is commonly preceded by oral premalignant lesions. The mortality rates have remained unchanged (50% within 5 years after diagnosis), and it is related to tobacco smoking and alcohol intake. Novel molecular markers for early diagnosis are urgently needed. The purpose of this study was to evaluate the diagnostic value of methylation level in a set of 18 genes by bisulfite next-generation sequencing. With minimally invasive oral brushing, 28 consecutive OSCC, one squamous cell carcinoma with sarcomatoid features, six high-grade squamous intraepithelial lesions (HGSIL), 30 normal contralateral mucosa from the same patients, and 65 healthy donors were evaluated for DNA methylation analyzing 18 target genes by quantitative bisulfite next-generation sequencing. We further evaluated an independent cohort (validation dataset) made of 20 normal donors, one oral fibroma, 14 oral lichen planus (OLP), three proliferative verrucous leukoplakia (PVL), and two OSCC. Comparing OSCC with normal healthy donors and contralateral mucosa in 355 CpGs, we identified the following epigenetically altered genes: ZAP70 , ITGA4 , KIF1A , PARP15 , EPHX3 , NTM , LRRTM1 , FLI1 , MIR193 , LINC00599 , PAX1 , and MIR137HG showing hypermethylation and MIR296 , TERT , and GP1BB showing hypomethylation . The behavior of ZAP70 , GP1BB , H19 , EPHX3 , and MIR193 fluctuated among different interrogated CpGs. The gap between normal and OSCC samples remained mostly the same (Kruskal-Wallis P values < 0.05), but the absolute values changed conspicuously. ROC curve analysis identified the most informative CpGs, and we correctly stratified OSCC and HGSIL from normal donors using a multiclass linear discriminant analysis in a 13-gene panel (AUC 0.981). Only the OSCC with sarcomatoid features was negative. Three contralateral mucosa were positive, a sign of a possible field cancerization. Among imprinted genes, only MIR296

  17. Differential effects of suppressors on hazardous sound pressure levels generated by AR-15 rifles: Considerations for recreational shooters, law enforcement, and the military.

    Science.gov (United States)

    Lobarinas, Edward; Scott, Ryan; Spankovich, Christopher; Le Prell, Colleen G

    2016-01-01

    Firearm discharges produce hazardous levels of impulse noise that can lead to permanent hearing loss. In the present study, we evaluated the effects of suppression, ammunition, and barrel length on AR-15 rifles. Sound levels were measured left/right of a user's head, and 1-m left of the muzzle, per MIL-STD-1474-D, under both unsuppressed and suppressed conditions. Nine commercially available AR-15 rifles and 14 suppressors were used. Suppressors significantly decreased peak dB SPL at the 1-m location and the left ear location. However, under most rifle/ammunition conditions, levels remained above 140 dB peak SPL near a user's right ear. In a subset of conditions, subsonic ammunition produced values near or below 140 dB peak SPL. Overall suppression ranged from 7-32 dB across conditions. These data indicate that (1) suppressors reduce discharge levels to 140 dB peak SPL or below in only a subset of AR-15 conditions, (2) shorter barrel length and use of muzzle brake devices can substantially increase exposure level for the user, and (3) there are significant left/right ear sound pressure differences under suppressed conditions as a function of the AR-15 direct impingement design that must be considered during sound measurements to fully evaluate overall efficacy.

  18. 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.

  19. 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

  20. 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...

  1. 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.

  2. 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)

  3. 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.

  4. 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

  5. Myeloid derived suppressor cells as therapeutic target in hematological malignancies

    Directory of Open Access Journals (Sweden)

    Kim eDe Veirman

    2014-12-01

    Full Text Available Myeloid derived suppressor cells (MDSC are a heterogeneous population of immature myeloid cells that accumulate during pathological conditions such as cancer and are associated with a poor clinical outcome. MDSC expansion hampers the host anti-tumor immune response by inhibition of T cell proliferation, cytokine secretion and recruitment of regulatory T cells. In addition, MDSC exert non-immunological functions including the promotion of angiogenesis, tumor invasion and metastasis. Recent years, MDSC are considered as a potential target in solid tumors and hematological malignancies to enhance the effects of currently used immune modulating agents. This review focuses on the characteristics, distribution, functions, cell-cell interactions and targeting of MDSC in hematological malignancies including multiple myeloma, lymphoma and leukemia.

  6. Identification of an MLC suppressor cell population in acute leukemia

    International Nuclear Information System (INIS)

    Bryan, C.F.; Broxmeyer, H.E.; Hansen, J.; Pollack, M.; Dupont, B.

    1978-01-01

    The MLC data from the 20 nonsuppressing patients and the 10 suppressing leukemia patients were analyzed with regard to HLA-A, -B, and -C antigens in the leukemia patients and compared with the presence or absence of suppression. These results demonstrate a significant increase (p < 0.02, Mann-Whitney U test) of HLA antigens Al, A3, and A11 in the leukemia suppressor group. Seven of the 10 leukemia patients showing suppression were A1, A3, or A11, while only 4 of the 20 nonsuppressing leukemia patients carried any of these three HLA-A antigens. The studies demonstrate that a nonspecific suppression of MLC responses is observed in 33% of the patients with acute leukemia

  7. The protein histidine phosphatase LHPP is a tumour suppressor.

    Science.gov (United States)

    Hindupur, Sravanth K; Colombi, Marco; Fuhs, Stephen R; Matter, Matthias S; Guri, Yakir; Adam, Kevin; Cornu, Marion; Piscuoglio, Salvatore; Ng, Charlotte K Y; Betz, Charles; Liko, Dritan; Quagliata, Luca; Moes, Suzette; Jenoe, Paul; Terracciano, Luigi M; Heim, Markus H; Hunter, Tony; Hall, Michael N

    2018-03-29

    Histidine phosphorylation, the so-called hidden phosphoproteome, is a poorly characterized post-translational modification of proteins. Here we describe a role of histidine phosphorylation in tumorigenesis. Proteomic analysis of 12 tumours from an mTOR-driven hepatocellular carcinoma mouse model revealed that NME1 and NME2, the only known mammalian histidine kinases, were upregulated. Conversely, expression of the putative histidine phosphatase LHPP was downregulated specifically in the tumours. We demonstrate that LHPP is indeed a protein histidine phosphatase. Consistent with these observations, global histidine phosphorylation was significantly upregulated in the liver tumours. Sustained, hepatic expression of LHPP in the hepatocellular carcinoma mouse model reduced tumour burden and prevented the loss of liver function. Finally, in patients with hepatocellular carcinoma, low expression of LHPP correlated with increased tumour severity and reduced overall survival. Thus, LHPP is a protein histidine phosphatase and tumour suppressor, suggesting that deregulated histidine phosphorylation is oncogenic.

  8. PML tumor suppressor protein is required for HCV production

    International Nuclear Information System (INIS)

    Kuroki, Misao; Ariumi, Yasuo; Hijikata, Makoto; Ikeda, Masanori; Dansako, Hiromichi; Wakita, Takaji; Shimotohno, Kunitada; Kato, Nobuyuki

    2013-01-01

    Highlights: ► PML tumor suppressor protein is required for HCV production. ► PML is dispensable for HCV RNA replication. ► HCV could not alter formation of PML-NBs. ► INI1 and DDX5, PML-related proteins, are involved in HCV life cycle. -- Abstract: PML tumor suppressor protein, which forms discrete nuclear structures termed PML-nuclear bodies, has been associated with several cellular functions, including cell proliferation, apoptosis and antiviral defense. Recently, it was reported that the HCV core protein colocalizes with PML in PML-NBs and abrogates the PML function through interaction with PML. However, role(s) of PML in HCV life cycle is unknown. To test whether or not PML affects HCV life cycle, we examined the level of secreted HCV core and the infectivity of HCV in the culture supernatants as well as the level of HCV RNA in HuH-7-derived RSc cells, in which HCV-JFH1 can infect and efficiently replicate, stably expressing short hairpin RNA targeted to PML. In this context, the level of secreted HCV core and the infectivity in the supernatants from PML knockdown cells was remarkably reduced, whereas the level of HCV RNA in the PML knockdown cells was not significantly affected in spite of very effective knockdown of PML. In fact, we showed that PML is unrelated to HCV RNA replication using the subgenomic HCV-JFH1 replicon RNA, JRN/3-5B. Furthermore, the infectivity of HCV-like particle in the culture supernatants was significantly reduced in PML knockdown JRN/3-5B cells expressing core to NS2 coding region of HCV-JFH1 genome using the trans-packaging system. Finally, we also demonstrated that INI1 and DDX5, the PML-related proteins, are involved in HCV production. Taken together, these findings suggest that PML is required for HCV production.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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)

  18. A Location Privacy Aware Friend Locator

    DEFF Research Database (Denmark)

    Siksnys, Laurynas; Thomsen, Jeppe Rishede; Saltenis, Simonas

    2009-01-01

    to trade their location privacy for quality of service, limiting the attractiveness of the services. The challenge is to develop a communication-efficient solution such that (i) it detects proximity between a user and the user’s friends, (ii) any other party is not allowed to infer the location of the user...

  19. 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.

  20. Differential expression patterns of metastasis suppressor proteins in basal cell carcinoma.

    Science.gov (United States)

    Bozdogan, Onder; Yulug, Isik G; Vargel, Ibrahim; Cavusoglu, Tarik; Karabulut, Ayse A; Karahan, Gurbet; Sayar, Nilufer

    2015-08-01

    Basal cell carcinomas (BCCs) are common malignant skin tumors. Despite having a significant invasion capacity, they metastasize only rarely. Our aim in this study was to detect the expression patterns of the NM23-H1, NDRG1, E-cadherin, RHOGDI2, CD82/KAI1, MKK4, and AKAP12 metastasis suppressor proteins in BCCs. A total of 96 BCC and 10 normal skin samples were included for the immunohistochemical study. Eleven frozen BCC samples were also studied by quantitative real time polymerase chain reaction (qRT-PCR) to detect the gene expression profile. NM23-H1 was strongly and diffusely expressed in all types of BCC. Significant cytoplasmic expression of NDRG1 and E-cadherin was also detected. However, AKAP12 and CD82/KAI1 expression was significantly decreased. The expressions of the other proteins were somewhere between the two extremes. Similarly, qRT-PCR analysis showed down-regulation of AKAP12 and up-regulation of NM23-H1 and NDRG1 in BCC. Morphologically aggressive BCCs showed significantly higher cytoplasmic NDRG1 expression scores and lower CD82/KAI1 scores than non-aggressive BCCs. The relatively preserved levels of NM23-H1, NDRG1, and E-cadherin proteins may have a positive effect on the non-metastasizing features of these tumors. © 2014 The International Society of Dermatology.

  1. 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.

  2. Saponin Inhibits Hepatitis C Virus Propagation by Up-regulating Suppressor of Cytokine Signaling 2

    Science.gov (United States)

    Kang, Sang-Min; Min, Saehong; Son, Kidong; Lee, Han Sol; Park, Eun Mee; Ngo, Huong T. T.; Tran, Huong T. L.; Lim, Yun-Sook; Hwang, Soon B.

    2012-01-01

    Saponins are a group of naturally occurring plant glycosides which possess a wide range of pharmacological properties, including anti-tumorigenic and antiviral activities. To investigate whether saponin has anti-hepatitis C virus (HCV) activity, we examined the effect of saponin on HCV replication. HCV replication was efficiently inhibited at a concentration of 10 µg/ml of saponin in cell culture grown HCV (HCVcc)-infected cells. Inhibitory effect of saponin on HCV replication was verified by quantitative real-time PCR, reporter assay, and immunoblot analysis. In addition, saponin potentiated IFN-α-induced anti-HCV activity. Moreover, saponin exerted antiviral activity even in IFN-α resistant mutant HCVcc-infected cells. To investigate how cellular genes were regulated by saponin, we performed microarray analysis using HCVcc-infected cells. We demonstrated that suppressor of cytokine signaling 2 (SOCS2) protein level was distinctively increased by saponin, which in turn resulted in inhibition of HCV replication. We further showed that silencing of SOCS2 resurrected HCV replication and overexpression of SOCS2 suppressed HCV replication. These data imply that saponin inhibits HCV replication via SOCS2 signaling pathway. These findings suggest that saponin may be a potent therapeutic agent for HCV patients. PMID:22745742

  3. 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.

  4. 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.

  5. miR-34a expands myeloid-derived suppressor cells via apoptosis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Anfei, E-mail: huang_anfei@163.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Zhang, Haitao, E-mail: zhanghtjp@126.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215021, Jiangsu Province (China); Chen, Si, E-mail: chensisdyxb@126.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Xia, Fei, E-mail: xiafei87@gmail.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Yang, Yi, E-mail: 602744364@qq.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Dong, Fulu, E-mail: adiok0903@126.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Sun, Di, E-mail: dongfl@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Xiong, Sidong, E-mail: sdxiong@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China); Zhang, Jinping, E-mail: j_pzhang@suda.edu.cn [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu Province (China)

    2014-08-15

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population and show significant expansion under pathological conditions. microRNA plays important roles in many biological processes, whether microRNAs have a function in the expansion of MDSCs is still not very clear. In this study, miR-34a overexpression can induce the expansion of MDSCs in bone marrow chimera and transgenic mice model. The experimental results suggest that miR-34a inhibited the apoptosis of MDSCs but did not affect the proliferation of MDSCs. The distinct mRNA microarray profiles of MDSCs of wild type and miR-34a over-expressing MDSCs combined with the target prediction of miR-34a suggest that miR-34a may target genes such as p2rx7, Tia1, and plekhf1 to inhibit the apoptosis of MDSCs. Taken together, miR-34a contributes to the expansion of MDSCs by inhibiting the apoptosis of MDSCs. - Highlights: • Over-expression of miR-34a increases the number of MDSCs. • miR-34a inhibits the apoptosis of MDSCs, but does not affects their proliferation. • miR-34a may inhibit the apoptosis of MDSCs via targeting the p2rx7, Tia1 and plekhf1.

  6. 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.

  7. ZFP226 is a novel artificial transcription factor for selective activation of tumor suppressor KIBRA.

    Science.gov (United States)

    Schelleckes, Katrin; Schmitz, Boris; Lenders, Malte; Mewes, Mirja; Brand, Stefan-Martin; Brand, Eva

    2018-03-09

    KIBRA has been suggested as a key regulator of the hippo pathway, regulating organ size, cell contact inhibition as well as tissue regeneration and tumorigenesis. Recently, alterations of KIBRA expression caused by promotor methylation have been reported for several types of cancer. Our current study aimed to design an artificial transcription factor capable of re-activating expression of the tumor suppressor KIBRA and the hippo pathway. We engineered a new gene named 'ZFP226' encoding for a ~23 kDa fusion protein. ZFP226 belongs to the Cys2-His2 zinc finger type and recognizes a nine base-pair DNA sequence 5'-GGC-GGC-GGC-3' in the KIBRA core promoter P1a. ZFP226 showed nuclear localization in human immortalized kidney epithelial cells and activated the KIBRA core promoter (p < 0.001) resulting in significantly increased KIBRA mRNA and protein levels (p < 0.001). Furthermore, ZFP226 led to activation of hippo signaling marked by elevated YAP and LATS phosphorylation. In Annexin V flow cytometry assays ZFP226 overexpression showed strong pro-apoptotic capacity on MCF-7 breast cancer cells (p < 0.01 early-, p < 0.001 late-apoptotic cells). We conclude that the artificial transcription factor ZFP226 can be used for target KIBRA and hippo pathway activation. This novel molecule may represent a molecular tool for the development of future applications in cancer treatment.

  8. Tumor suppressor maspin as a modulator of host immune response to cancer

    Directory of Open Access Journals (Sweden)

    Sijana H. Dzinic

    2015-10-01

    Full Text Available Despite the promising clinical outcome, the primary challenge of the curative cancer immunotherapy is to overcome the dichotomy of the immune response: tumor-evoked immunostimulatory versus tumor-induced immunosuppressive. The goal needs to be two-fold, to re-establish sustainable antitumor-cancer immunity and to eliminate immunosuppression. The successful elimination of cancer cells by immunosurveillance requires the antigenic presentation of the tumor cells or tumor-associated antigens and the expression of immunostimulatory cytokines and chemokines by cancer and immune cells. Tumors are heterogeneous and as such, some of the tumor cells are thought to have stem cell characteristics that enable them to suppress or desensitize the host immunity due to acquired epigenetic changes. A central mechanism underlying tumor epigenetic instability is the increased histone deacetylase (HDAC-mediated repression of HDAC-target genes regulating homeostasis and differentiation. It was noted that pharmacological HDAC inhibitors are not effective in eliminating tumor cells partly because they may induce immunosuppression. We have shown that epithelial-specific tumor suppressor maspin, an ovalbumin-like non-inhibitory serine protease inhibitor, reprograms tumor cells toward better differentiated phenotypes by inhibiting HDAC1. Recently, we uncovered a novel function of maspin in directing host immunity towards tumor elimination. In this review, we discuss the maspin and maspin/HDAC1 interplay in tumor biology and immunology. We propose that maspin based therapies may eradicate cancer.

  9. 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

  10. Immune suppressor factor confers stromal cell line with enhanced supporting activity for hematopoietic stem cells

    International Nuclear Information System (INIS)

    Nakajima, Hideaki; Shibata, Fumi; Fukuchi, Yumi; Goto-Koshino, Yuko; Ito, Miyuki; Urano, Atsushi; Nakahata, Tatsutoshi; Aburatani, Hiroyuki; Kitamura, Toshio

    2006-01-01

    Immune suppressor factor (ISF) is a subunit of the vacuolar ATPase proton pump. We earlier identified a short form of ISF (ShIF) as a stroma-derived factor that supports cytokine-independent growth of mutant Ba/F3 cells. Here, we report that ISF/ShIF supports self-renewal and expansion of primary hematopoietic stem cells (HSCs). Co-culture of murine bone marrow cells with a stromal cell line overexpressing ISF or ShIF (MS10/ISF or MS10/ShIF) not only enhanced their colony-forming activity and the numbers of long-term culture initiating cells, but also maintained the competitive repopulating activity of HSC. This stem cell supporting activity depended on the proton-transfer function of ISF/ShIF. Gene expression analysis of ISF/ShIF-transfected cell lines revealed down-regulation of secreted frizzled-related protein-1 and tissue inhibitor of metalloproteinase-3, and the restoration of their expressions in MS10/ISF cells partially reversed its enhanced LTC-IC supporting activity to a normal level. Thes