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  1. Astroglial c-Myc overexpression predisposes mice to primary malignant gliomas

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    Jensen, Niels Aagaard; Pedersen, Karen-Marie; Lihme, Frederikke

    2003-01-01

    in the ventricular zone and, analogous to human glioblastomas, exhibit molecular and morphological heterogeneity. Levels of connexin 43 in the majority of the tumors are unaltered from normal tissue, indicating that GEM tumors have retained the capacity to establish syncytial networks. In line with this, individual...... the neoplastic process, presumably by inducing the sustained growth of early astroglial cells. This is in contrast to most other transgenic studies in which c-Myc overexpression requires co-operating transgenes for rapid tumor induction....

  2. Overexpression of c-myc induces epithelial mesenchymal transition in mammary epithelial cells.

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    Cho, Kyoung Bin; Cho, Min Kyong; Lee, Won Young; Kang, Keon Wook

    2010-07-28

    The c-myc gene is frequently overexpressed in human breast cancer and its target genes are involved in tumorigenesis. Epithelial mesenchymal transitions (EMT), where cells undergo a developmental switch from a polarized epithelial phenotype to a highly motile mesenchymal phenotype, are associated with invasion and motility of cancer cells. Basal E-cadherin expression was down-regulated in c-myc overexpressing MCF10A (c-myc-MCF10A) cells compared to GFP-overexpressing MCF10A (GFP-MCF10A) cells, while N-cadherin was distinctly increased in c-myc-MCF10A cells. Given that glycogen synthase kinase-3beta (GSK-3beta) and the snail axis have key roles in E-cadherin deregulation during EMT, we investigated the role of GSK-3beta/snail signaling pathways in the induction of EMT by c-myc overexpression. In contrast to GFP-MCF10A cells, both the transcriptional activity and the ubiquitination-dependent protein stability of snail were enhanced in c-myc-MCF10A cells, and this was reversed by GSK-3beta overexpression. We also found that c-myc overexpression inhibits GSK-3beta activity through activation of extracellular signal-regulated kinase (ERK). Inhibition of ERK by dominant negative mutant transfection or chemical inhibitor significantly suppressed snail gene transcription. These results suggest that c-myc overexpression during transformation of mammary epithelial cells (MEC) is involved in EMTs via ERK-dependent GSK-3beta inactivation and subsequent snail activation.

  3. Genetic and genomic analysis modeling of germline c-MYC overexpression and cancer susceptibility

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    Nunes Virginia

    2008-01-01

    Full Text Available Abstract Background Germline genetic variation is associated with the differential expression of many human genes. The phenotypic effects of this type of variation may be important when considering susceptibility to common genetic diseases. Three regions at 8q24 have recently been identified to independently confer risk of prostate cancer. Variation at 8q24 has also recently been associated with risk of breast and colorectal cancer. However, none of the risk variants map at or relatively close to known genes, with c-MYC mapping a few hundred kilobases distally. Results This study identifies cis-regulators of germline c-MYC expression in immortalized lymphocytes of HapMap individuals. Quantitative analysis of c-MYC expression in normal prostate tissues suggests an association between overexpression and variants in Region 1 of prostate cancer risk. Somatic c-MYC overexpression correlates with prostate cancer progression and more aggressive tumor forms, which was also a pathological variable associated with Region 1. Expression profiling analysis and modeling of transcriptional regulatory networks predicts a functional association between MYC and the prostate tumor suppressor KLF6. Analysis of MYC/Myc-driven cell transformation and tumorigenesis substantiates a model in which MYC overexpression promotes transformation by down-regulating KLF6. In this model, a feedback loop through E-cadherin down-regulation causes further transactivation of c-MYC. Conclusion This study proposes that variation at putative 8q24 cis-regulator(s of transcription can significantly alter germline c-MYC expression levels and, thus, contribute to prostate cancer susceptibility by down-regulating the prostate tumor suppressor KLF6 gene.

  4. Driving gradual endogenous c-myc overexpression by flow-sorting: intracellular signaling and tumor cell phenotype correlate with oncogene expression

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    Knudsen, Kasper Jermiin; Holm, G.M.N.; Krabbe, J.S.

    2009-01-01

    Insulin-exposed rat mammary cancer cells were flow sorted based on a c-myc reporter plasmid encoding a destabilized green fluorescent protein. Sorted cells exhibited gradual increases in c-myc levels. Cells overexpressing c-myc by only 10% exhibited phenotypic changes attributable to c-myc overex......Insulin-exposed rat mammary cancer cells were flow sorted based on a c-myc reporter plasmid encoding a destabilized green fluorescent protein. Sorted cells exhibited gradual increases in c-myc levels. Cells overexpressing c-myc by only 10% exhibited phenotypic changes attributable to c...

  5. Co-overexpression of bcl-2 and c-myc in uterine cervix carcinomas and premalignant lesions

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    Z. Protrka

    2011-03-01

    Full Text Available To establish the role of co-overexpression of bcl-2 and c-myc protooncogenes in uterine cervix carcinogenesis, we examined 138 tissue samples of low grade cervical squamous intraepithelial lesions (SIL, high grade SIL, portio vaginalis uteri (PVU carcinoma in situ and PVU carcinoma invasive, stage IA-IIA (study group and 36 samples without SIL or malignancy (control group. The expression of bcl-2 and c-myc was detected immunohistochemically using a monoclonal antibody. Fisher’s exact test (P<0.05 was used to assess statistical significance. Overexpression of bcl-2 was found to increase in direct relation to the grade of the cervical lesions. High sensitivity was of great diagnostic significance for the detection of these types of changes in the uterine cervix. On the basis of high predictive values it can be said that in patients with bcl-2 overexpression there is a great possibility that they have premalignant or malignant changes in the uterine cervix. Co-overexpression of bcl-2 and c-myc oncogenes was found only in patients with PVU invasive carcinoma (6/26-23.0%. Statistically significant difference was not found in the frequency of co-overexpression in patients with PVU invasive carcinoma in relation to the control group (Fisher’s test; P=0.064. The method's sensitivity of determining these oncogenes with the aim of detecting PVU invasive carcinoma was 23%, while specificity was 72.2%. On the basis of high predictive values (100%, speaking in statistical terms, it can be concluded that all patients with co-overexpression of bcl-2 and c-myc oncogenes will have PVU invasive carcinoma. We confirmed in our research that co-overexpression of bcl-2 and c-myc oncogenes was increased only in PVU invasive carcinoma. However, a more extensive series of samples and additional tests are required to establish the prognostic significance of bcl-2 and c-myc co-overexpression in cervical carcinogenesis.

  6. Tissue array for Tp53, C-myc, CCND1 gene over-expression in different tumors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To rapidly detect molecular alterations in different malignancies and investigate the possible role of Tp53, C-myc, and CCND1 genes in development of tumors in human organs and their adjacent normal tissues, as well as the possible relation between well- and poorly-differentiated tumors. METHODS: A tissue array consisting of seven different tumors was generated. The tissue array included 120 points of esophagus, 120 points of stomach, 80 points of rectum, 60 points of thyroid gland, 100 points of mammary gland, 80 points ofliver, and 80 points of colon. Expressions of Tp53, C-myc, and CCND1 were determined by RNA in situ hybridization. 3' terminal digoxin-labeled anti-sense single stranded oligonucleotide and locked nucleic acid modifying probe were used.RESULTS: The expression level of Tp53 gene was higher in six different carcinoma tissue samples than in paracancerous tissue samples with the exception in colon carcinoma tissue samples (P < 0.05). The expression level of CCND1 gene was significantly different in different carcinoma tissue samples with the exception in esophagus and colon carcinoma tissue samples. The expression level of C-myc gene was different in esophagus carcinoma tissue samples (x2 = 18.495, P = 0.000), stomach carcinoma tissue samples (x2 = 23.750, P = 0.000), and thyroid gland tissue samples (x2 = 10.999, P = 0.004). The intensity of signals was also different in different carcinoma tissue samples and paracancerous tissue samples.CONCLUSION: Over-expression of the Tp53, CCND1, and C-myc genes appears to play a role in development of human cancer by regulating the expression of mRNA. Tp53, CCND1 and C-myc genes are significantly correlated with the development of different carcinomas.

  7. Correlation of chromosomal polysomy with overexpression of c-myc and c-erbB-2 in primary nasopharyngeal carcinoma: Tissue microarray study

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Many genes may be involved in nasopharyngeal carcinoma (NPC) development and progression. Several known oncogenes, including c-myc and c-erb-B2, have been shown to have structural alteration and aberrant expression in NPC. Here, we constructed a tissue microarray to determine the status of c-myc and c-erbB-2 oncogenes at the DNA and protein levels using interphase fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) and to define the diagnostic, prognostic importance of the genetic changes. Results showed that amplification of c-myc and c-erbB-2 was not found in NPC. Polysomy 8 and 17 were observed in 43%-50% and 20%-27% of NPC tumors, respectively. Overexpressions of c-myc and c-erbB-2 oncoproteins were detected in 53.6% and 54.5% cases of NPC with polysomy 8 and 17, respectively. There was no significant correlation between c-myc and c-erbB-2 staining and the clinical stage. But overexpression of c-erbB-2 was associated with polysomy 17 in NPC. These findings suggest that chromosomal polysomy, not gene amplification, may be partially responsible for the upregulated expression of c-erbB-2 oncogene in NPC.

  8. The Dysregulation of Polyamine Metabolism in Colorectal Cancer Is Associated with Overexpression of c-Myc and C/EBPβ rather than Enterotoxigenic Bacteroides fragilis Infection

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    Anastasiya V. Snezhkina

    2016-01-01

    Full Text Available Colorectal cancer is one of the most common cancers in the world. It is well known that the chronic inflammation can promote the progression of colorectal cancer (CRC. Recently, a number of studies revealed a potential association between colorectal inflammation, cancer progression, and infection caused by enterotoxigenic Bacteroides fragilis (ETBF. Bacterial enterotoxin activates spermine oxidase (SMO, which produces spermidine and H2O2 as byproducts of polyamine catabolism, which, in turn, enhances inflammation and tissue injury. Using qPCR analysis, we estimated the expression of SMOX gene and ETBF colonization in CRC patients. We found no statistically significant associations between them. Then we selected genes involved in polyamine metabolism, metabolic reprogramming, and inflammation regulation and estimated their expression in CRC. We observed overexpression of SMOX, ODC1, SRM, SMS, MTAP, c-Myc, C/EBPβ (CREBP, and other genes. We found that two mediators of metabolic reprogramming, inflammation, and cell proliferation c-Myc and C/EBPβ may serve as regulators of polyamine metabolism genes (SMOX, AZIN1, MTAP, SRM, ODC1, AMD1, and AGMAT as they are overexpressed in tumors, have binding site according to ENCODE ChIP-Seq data, and demonstrate strong coexpression with their targets. Thus, increased polyamine metabolism in CRC could be driven by c-Myc and C/EBPβ rather than ETBF infection.

  9. c-Myc dependent expression of pro-apoptotic Bim renders HER2-overexpressing breast cancer cells dependent on anti-apoptotic Mcl-1

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    Jézéquel Pascal

    2011-09-01

    Full Text Available Abstract Background Anti-apoptotic signals induced downstream of HER2 are known to contribute to the resistance to current treatments of breast cancer cells that overexpress this member of the EGFR family. Whether or not some of these signals are also involved in tumor maintenance by counteracting constitutive death signals is much less understood. To address this, we investigated what role anti- and pro-apoptotic Bcl-2 family members, key regulators of cancer cell survival, might play in the viability of HER2 overexpressing breast cancer cells. Methods We used cell lines as an in vitro model of HER2-overexpressing cells in order to evaluate how anti-apoptotic Bcl-2, Bcl-xL and Mcl-1, and pro-apoptotic Puma and Bim impact on their survival, and to investigate how the constitutive expression of these proteins is regulated. Expression of the proteins of interest was confirmed using lysates from HER2-overexpressing tumors and through analysis of publicly available RNA expression data. Results We show that the depletion of Mcl-1 is sufficient to induce apoptosis in HER2-overexpressing breast cancer cells. This Mcl-1 dependence is due to Bim expression and it directly results from oncogenic signaling, as depletion of the oncoprotein c-Myc, which occupies regions of the Bim promoter as evaluated in ChIP assays, decreases Bim levels and mitigates Mcl-1 dependence. Consistently, a reduction of c-Myc expression by inhibition of mTORC1 activity abrogates occupancy of the Bim promoter by c-Myc, decreases Bim expression and promotes tolerance to Mcl-1 depletion. Western blot analysis confirms that naïve HER2-overexpressing tumors constitutively express detectable levels of Mcl-1 and Bim, while expression data hint on enrichment for Mcl-1 transcripts in these tumors. Conclusions This work establishes that, in HER2-overexpressing tumors, it is necessary, and maybe sufficient, to therapeutically impact on the Mcl-1/Bim balance for efficient induction of

  10. Perturbation of 14q32 miRNAs-cMYC gene network in osteosarcoma.

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    Thayanithy, Venugopal; Sarver, Aaron L; Kartha, Reena V; Li, Lihua; Angstadt, Andrea Y; Breen, Matthew; Steer, Clifford J; Modiano, Jaime F; Subramanian, Subbaya

    2012-01-01

    Osteosarcoma (OS) is the common histological form of primary bone cancer and one of the leading aggressive cancers in children under age fifteen. Although several genetic predisposing conditions have been associated with OS the understanding of its molecular etiology is limited. Here, we show that microRNAs (miRNAs) at the chr.14q32 locus are significantly downregulated in osteosarcoma compared to normal bone tissues. Bioinformatic predictions identified that a subset of 14q32 miRNAs (miR-382, miR-369-3p, miR-544 and miR-134) could potentially target cMYC transcript. The physical interaction between these 14q32 miRNAs and cMYC was validated using reporter assays. Further, restoring expression of these four 14q32 miRNAs decreased cMYC levels and induced apoptosis in Saos2 cells. We also show that exogenous expression of 14q32 miRNAs in Saos2 cells significantly downregulated miR-17-92, a transcriptional target of cMYC. The pro-apoptotic effect of 14q32 miRNAs in Saos2 cells was rescued either by overexpression of cMYC cDNA without the 3'UTR or with miR-17-92 cluster. Further, array comparative genomic hybridization studies showed no DNA copy number changes at 14q32 locus in OS patient samples suggesting that downregulation of 14q32 miRNAs are not due to deletion at this locus. Together, our data support a model where the deregulation of a network involving 14q32 miRNAs, cMYC and miR-17-92 miRNAs could contribute to osteosarcoma pathogenesis.

  11. Ezrin mediates c-Myc actions in prostate cancer cell invasion

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    Chuan, Yin Choy; Iglesias Gato, Diego; Fernandez-Perez, L;

    2010-01-01

    The forced overexpression of c-Myc in mouse prostate and in normal human prostate epithelial cells results in tumor transformation with an invasive phenotype. How c-Myc regulates cell invasion is poorly understood. In this study, we have investigated the interplay of c-Myc and androgens in the re...

  12. Absence of DNA damage after 60-Hz electromagnetic field exposure combined with ionizing radiation, hydrogen peroxide, or c-Myc overexpression.

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    Jin, Yeung Bae; Choi, Seo-Hyun; Lee, Jae Seon; Kim, Jae-Kyung; Lee, Ju-Woon; Hong, Seung-Cheol; Myung, Sung Ho; Lee, Yun-Sil

    2014-03-01

    The principal objective of this study was to assess the DNA damage in a normal cell line system after exposure to 60 Hz of extremely low frequency magnetic field (ELF-MF) and particularly in combination with various external factors, via comet assays. NIH3T3 mouse fibroblast cells, WI-38 human lung fibroblast cells, L132 human lung epithelial cells, and MCF10A human mammary gland epithelial cells were exposed for 4 or 16 h to a 60-Hz, 1 mT uniform magnetic field in the presence or absence of ionizing radiation (IR, 1 Gy), H(2)O(2) (50 μM), or c-Myc oncogenic activation. The results obtained showed no significant differences between the cells exposed to ELF-MF alone and the unexposed cells. Moreover, no synergistic or additive effects were observed after 4 or 16 h of pre-exposure to 1 mT ELF-MF or simultaneous exposure to ELF-MF combined with IR, H(2)O(2), or c-Myc activation.

  13. Effects of alcohol on c-Myc protein in the brain.

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    Akinyeke, Tunde; Weber, Sydney J; Davenport, April T; Baker, Erich J; Daunais, James B; Raber, Jacob

    2017-03-01

    Alcoholism is a disorder categorized by significant impairment that is directly related to persistent and extreme use of alcohol. The effects of alcoholism on c-Myc protein expression in the brain have been scarcely studied. This is the first study to investigate the role different characteristics of alcoholism have on c-Myc protein in the brain. We analyzed c-Myc protein in the hypothalamus and amygdala from five different animal models of alcohol abuse. c-Myc protein was increased following acute ethanol exposure in a mouse knockout model and following chronic ethanol consumption in vervet monkeys. We also observed increases in c-Myc protein exposure in animals that are genetically predisposed to alcohol and methamphetamine abuse. Lastly, c-Myc protein was increased in animals that were acutely exposed to methamphetamine when compared to control treated animals. These results suggest that in substance abuse c-Myc plays an important role in the brain's response.

  14. Rictor regulates FBXW7-dependent c-Myc and cyclin E degradation in colorectal cancer cells

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    Guo, Zheng [Markey Cancer Center, The University of Kentucky, 800 Rose Street, Lexington, KY 40536 (United States); Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Dadao Bei, Guangzhou 510515 (China); Zhou, Yuning [Markey Cancer Center, The University of Kentucky, 800 Rose Street, Lexington, KY 40536 (United States); Evers, B. Mark [Markey Cancer Center, The University of Kentucky, 800 Rose Street, Lexington, KY 40536 (United States); Department of Surgery, The University of Kentucky, 800 Rose Street, Lexington, KY 40536 (United States); Wang, Qingding, E-mail: qingding.wang@uky.edu [Markey Cancer Center, The University of Kentucky, 800 Rose Street, Lexington, KY 40536 (United States); Department of Surgery, The University of Kentucky, 800 Rose Street, Lexington, KY 40536 (United States)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Rictor associates with FBXW7 to form an E3 complex. Black-Right-Pointing-Pointer Knockdown of rictor decreases ubiquitination of c-Myc and cylin E. Black-Right-Pointing-Pointer Knockdown of rictor increases protein levels of c-Myc and cylin E. Black-Right-Pointing-Pointer Overexpression of rictor induces the degradation of c-Myc and cyclin E proteins. Black-Right-Pointing-Pointer Rictor regulation of c-Myc and cyclin E requires FBXW7. -- Abstract: Rictor (Rapamycin-insensitive companion of mTOR) forms a complex with mTOR and phosphorylates and activates Akt. Activation of Akt induces expression of c-Myc and cyclin E, which are overexpressed in colorectal cancer and play an important role in colorectal cancer cell proliferation. Here, we show that rictor associates with FBXW7 to form an E3 complex participating in the regulation of c-Myc and cyclin E degradation. The Rictor-FBXW7 complex is biochemically distinct from the previously reported mTORC2 and can be immunoprecipitated independently of mTORC2. Moreover, knocking down of rictor in serum-deprived colorectal cancer cells results in the decreased ubiquitination and increased protein levels of c-Myc and cyclin E while overexpression of rictor induces the degradation of c-Myc and cyclin E proteins. Genetic knockout of FBXW7 blunts the effects of rictor, suggesting that rictor regulation of c-Myc and cyclin E requires FBXW7. Our findings identify rictor as an important component of FBXW7 E3 ligase complex participating in the regulation of c-Myc and cyclin E protein ubiquitination and degradation. Importantly, our results suggest that elevated growth factor signaling may contribute to decrease rictor/FBXW7-mediated ubiquitination of c-Myc and cyclin E, thus leading to accumulation of cyclin E and c-Myc in colorectal cancer cells.

  15. The Role of c-MYC in B-Cell Lymphomas: Diagnostic and Molecular Aspects.

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    Nguyen, Lynh; Papenhausen, Peter; Shao, Haipeng

    2017-04-05

    c-MYC is one of the most essential transcriptional factors, regulating a diverse array of cellular functions, including proliferation, growth, and apoptosis. Dysregulation of c-MYC is essential in the pathogenesis of a number of B-cell lymphomas, but is rarely reported in T-cell lymphomas. c-MYC dysregulation induces lymphomagenesis by loss of the tight control of c-MYC expression, leading to overexpression of intact c-MYC protein, in contrast to the somatic mutations or fusion proteins seen in many other oncogenes. Dysregulation of c-MYC in B-cell lymphomas occurs either as a primary event in Burkitt lymphoma, or secondarily in aggressive lymphomas such as diffuse large B-cell lymphoma, plasmablastic lymphoma, mantle cell lymphoma, or double-hit lymphoma. Secondary c-MYC changes include gene translocation and gene amplification, occurring against a background of complex karyotype, and most often confer aggressive clinical behavior, as evidenced in the double-hit lymphomas. In low-grade B-cell lymphomas, acquisition of c-MYC rearrangement usually results in transformation into highly aggressive lymphomas, with some exceptions. In this review, we discuss the role that c-MYC plays in the pathogenesis of B-cell lymphomas, the molecular alterations that lead to c-MYC dysregulation, and their effect on prognosis and diagnosis in specific types of B-cell lymphoma.

  16. Brief inactivation of c-Myc is not sufficient for sustained regression of c-Myc-induced tumours of pancreatic islets and skin epidermis

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    Zervou Sevasti

    2004-12-01

    Full Text Available Abstract Background Tumour regression observed in many conditional mouse models following oncogene inactivation provides the impetus to develop, and a platform to preclinically evaluate, novel therapeutics to inactivate specific oncogenes. Inactivating single oncogenes, such as c-Myc, can reverse even advanced tumours. Intriguingly, transient c-Myc inactivation proved sufficient for sustained osteosarcoma regression; the resulting osteocyte differentiation potentially explaining loss of c-Myc's oncogenic properties. But would this apply to other tumours? Results We show that brief inactivation of c-Myc does not sustain tumour regression in two distinct tissue types; tumour cells in pancreatic islets and skin epidermis continue to avoid apoptosis after c-Myc reactivation, by virtue of Bcl-xL over-expression or a favourable microenvironment, respectively. Moreover, tumours progress despite reacquiring a differentiated phenotype and partial loss of vasculature during c-Myc inactivation. Interestingly, reactivating c-Myc in β-cell tumours appears to result not only in further growth of the tumour, but also re-expansion of the accompanying angiogenesis and more pronounced β-cell invasion (adenocarcinoma. Conclusions Given that transient c-Myc inactivation could under some circumstances produce sustained tumour regression, the possible application of this potentially less toxic strategy in treating other tumours has been suggested. We show that brief inactivation of c-Myc fails to sustain tumour regression in two distinct models of tumourigenesis: pancreatic islets and skin epidermis. These findings challenge the potential for cancer therapies aimed at transient oncogene inactivation, at least under those circumstances where tumour cell differentiation and alteration of epigenetic context fail to reinstate apoptosis. Together, these results suggest that treatment schedules will need to be informed by knowledge of the molecular basis and

  17. Sulforaphane Inhibits c-Myc-Mediated Prostate Cancer Stem-Like Traits.

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    Vyas, Avani R; Moura, Michelle B; Hahm, Eun-Ryeong; Singh, Krishna Beer; Singh, Shivendra V

    2016-11-01

    Preventive and therapeutic efficiencies of dietary sulforaphane (SFN) against human prostate cancer have been demonstrated in vivo, but the underlying mechanism(s) by which this occurs is poorly understood. Here, we show that the prostate cancer stem cell (pCSC)-like traits, such as accelerated activity of aldehyde dehydrogenase 1 (ALDH1), enrichment of CD49f+ fraction, and sphere forming efficiency, are attenuated by SFN treatment. Interestingly, the expression of c-Myc, an oncogenic transcription factor that is frequently deregulated in prostate cancer cells, was markedly suppressed by SFN both in vitro and in vivo. This is biologically relevant, because the lessening of pCSC-like phenotypes mediated by SFN was attenuated when c-Myc was overexpressed. Naturally occurring thio, sulfinyl, and sulfonyl analogs of SFN were also effective in causing suppression of c-Myc protein level. However, basal glycolysis, a basic metabolic pathway that can also be promoted by c-Myc overexpression, was not largely suppressed by SFN, implying that, in addition to c-Myc, there might be another SFN-sensitive cellular factor, which is not directly involved in basal glycolysis, but cooperates with c-Myc to sustain pCSC-like phenotypes. Our study suggests that oncogenic c-Myc is a target of SFN to prevent and eliminate the onset of human prostate cancer. J. Cell. Biochem. 117: 2482-2495, 2016. © 2016 Wiley Periodicals, Inc.

  18. Glutathione Depletion Induced by c-Myc Downregulation Triggers Apoptosis on Treatment with Alkylating Agents

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    Annamaria Biroccio

    2004-05-01

    Full Text Available Here we investigate the mechanism(s involved in the c-Myc-dependent drug response of melanoma cells. By using three M14-derived c-Myc low-expressing clones, we demonstrate that alkylating agents, cisplatin and melphalan, trigger apoptosis in the c-Myc antisense transfectants, but not in the parental line. On the contrary, topoisomerase inhibitors, adriamycin and camptothecin, induce apoptosis to the same extent regardless of c-Myc expression. Because we previously demonstrated that c-Myc downregulation decreases glutathione (GSH content, we evaluated the role of GSH in the apoptosis induced by the different drugs. In control cells treated with one of the alkylating agents or the others, GSH depletion achieved by L-buthionine-sulfoximine preincubation opens the apoptotic pathway. The apoptosis proceeded through early Bax relocalization, cytochrome c release, concomitant caspase-9 activation, whereas reactive oxygen species production and alteration of mitochondria membrane potential were late events. That GSH was determining in the c-Myc-dependent druginduced apoptosis was demonstrated by altering the intracellular GSH content of the c-Myc low-expressing cells up to the level of controls. Indeed, GSH ethyl ester-mediated increase of GSH abrogated apoptosis induced by cisplatin and melphalan by inhibition of Baxicytochrome c redistribution. The relationship among c-Myc, GSH content, the response to alkylating agent has been also evaluated in the M14 Myc overexpressing clones as well as in the melanoma JR8 c-Myc antisense transfectants. All together, these results demonstrate that GSH plays a key role in governing c-Myc-dependent drug-induced apoptosis.

  19. c-Myc is a novel target of cell cycle arrest by honokiol in prostate cancer cells.

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    Hahm, Eun-Ryeong; Singh, Krishna Beer; Singh, Shivendra V

    2016-09-01

    Honokiol (HNK), a highly promising phytochemical derived from Magnolia officinalis plant, exhibits in vitro and in vivo anticancer activity against prostate cancer but the underlying mechanism is not fully clear. This study was undertaken to delineate the role of c-Myc in anticancer effects of HNK. Exposure of prostate cancer cells to plasma achievable doses of HNK resulted in a marked decrease in levels of total and/or phosphorylated c-Myc protein as well as its mRNA expression. We also observed suppression of c-Myc protein in PC-3 xenografts upon oral HNK administration. Stable overexpression of c-Myc in PC-3 and 22Rv1 cells conferred significant protection against HNK-mediated growth inhibition and G0-G1 phase cell cycle arrest. HNK treatment decreased expression of c-Myc downstream targets including Cyclin D1 and Enhancer of Zeste Homolog 2 (EZH2), and these effects were partially restored upon c-Myc overexpression. In addition, PC-3 and DU145 cells with stable knockdown of EZH2 were relatively more sensitive to growth inhibition by HNK compared with control cells. Finally, androgen receptor overexpression abrogated HNK-mediated downregulation of c-Myc and its targets particularly EZH2. The present study indicates that c-Myc, which is often overexpressed in early and late stages of human prostate cancer, is a novel target of prostate cancer growth inhibition by HNK.

  20. TELOMERASE ACTIVITY IN COLORECTAL CARCINOMA AND ITS CORRELATION WITH EXPRESSION OF C-MYC

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Lun; GE Lian-ying; ZHANG Gui-nian

    2005-01-01

    Objective: To study the role of telomerase activity and c-myc in pathogenesis and progression of colorectal carcinoma,and to investigate the possible regulatory mechanism of telomerase activation. Methods: A modified telomeric repeat amplification protocol (TRAP) and immunohistochemical staining was used to detect telomerase activity and the expression of c-myc in tissue samples from colorectal carcinoma, paracarcinomatousl tissues, normal mucosa, and adenomatoid polyp.Results: The positive rates of telomerase activity and c-myc expression were 83.33% and 80.00% in colorectal carcinoma,13.33% and 23.33% in paracarcinomatousl tissues, 13.33% and 20.00% in normal mucosa, and 10.00% and 45.00% in adenomatoid polyp respectively, they were significantly higher in colorectal carcinoma than in paracarcinomatousl tissues,normal mucosa, and adenomatoid polyp (P<0.05). The rates of telomerase activity and c-myc expression were much higher in colorectal carcinoma with lymph nodes metastases than that without lymph nodes metastases. The expression of c-myc was found being significantly higher in the telomerase positive colorectal carcinoma than in the telomerase negative group(P<0.05). Conclusion: The activation of telomerase and abnormal expression of c-myc might play an important role in the process of carcinogenesis and progression of colorectal carcinoma. The over-expression of c-myc may be related to telomerase activation and up-regulation in colorectal carcinoma.

  1. Inhibition of c-Myc overcomes cytotoxic drug resistance in acute myeloid leukemia cells by promoting differentiation.

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    Xiao-Na Pan

    Full Text Available Nowadays, drug resistance still represents a major obstacle to successful acute myeloid leukemia (AML treatment and the underlying mechanism is not fully elucidated. Here, we found that high expression of c-Myc was one of the cytogenetic characteristics in the drug-resistant leukemic cells. c-Myc over-expression in leukemic cells induced resistance to chemotherapeutic drugs, enhanced colony formation capacity and inhibited cell differentiation induced by all-trans retinoic acid (ATRA. Meanwhile, inhibition of c-Myc by shRNA or specific c-Myc inhibitor 10058-F4 rescued the sensitivity to cytotoxic drugs, restrained the colony formation ability and promoted differentiation. RT-PCR and western blotting analysis showed that down-regulation of C/EBPβ contributed to the poor differentiation state of leukemic cells induced by c-Myc over-expression. Importantly, over-expression of C/EBPβ could reverse c-Myc induced drug resistance. In primary AML cells, the c-Myc expression was negatively correlated with C/EBPβ. 10058-F4, displayed anti-proliferative activity and increased cellular differentiation with up-regulation of C/EBPβ in primary AML cells. Thus, our study indicated that c-Myc could be a novel target to overcome drug resistance, providing a new approach in AML therapy.

  2. TIP30 interacts with an estrogen receptor alpha-interacting coactivator CIA and regulates c-myc transcription.

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    Jiang, Chao; Ito, Mitsuhiro; Piening, Valerie; Bruck, Kristy; Roeder, Robert G; Xiao, Hua

    2004-06-25

    Deregulation of c-myc expression is implicated in the pathogenesis of many neoplasias. Estrogen receptor alpha (ERalpha) can increase the rate of c-myc transcription through the recruitment of a variety of cofactors to the promoter, yet the precise roles of these cofactors in transcription and tumorigenesis are largely unknown. We show here that a putative tumor suppressor TIP30, also called CC3 or Htatip2, interacts with an ERalpha-interacting coactivator CIA. Using chromatin immunoprecipitation assays, we demonstrate that TIP30 and CIA are distinct cofactors that are dynamically associated with the promoter and downstream regions of the c-myc gene in response to estrogen. Both TIP30 and CIA are recruited to the c-myc gene promoter by liganded ERalpha in the second transcription cycle. TIP30 overexpression represses ERalpha-mediated c-myc transcription, whereas TIP30 deficiency enhances c-myc transcription in both the absence and presence of estrogen. Ectopic CIA cooperates with TIP30 to repress ERalpha-mediated c-myc transcription. Moreover, virgin TIP30 knockout mice exhibit increased c-myc expression in mammary glands. Together, these results reveal an important role for TIP30 in the regulation of ERalpha-mediated c-myc transcription and suggest a mechanism for tumorigenesis promoted by TIP30 deficiency.

  3. Endogenous c-Myc is essential for p53-induced apoptosis in response to DNA damage in vivo.

    Science.gov (United States)

    Phesse, T J; Myant, K B; Cole, A M; Ridgway, R A; Pearson, H; Muncan, V; van den Brink, G R; Vousden, K H; Sears, R; Vassilev, L T; Clarke, A R; Sansom, O J

    2014-06-01

    Recent studies have suggested that C-MYC may be an excellent therapeutic cancer target and a number of new agents targeting C-MYC are in preclinical development. Given most therapeutic regimes would combine C-MYC inhibition with genotoxic damage, it is important to assess the importance of C-MYC function for DNA damage signalling in vivo. In this study, we have conditionally deleted the c-Myc gene in the adult murine intestine and investigated the apoptotic response of intestinal enterocytes to DNA damage. Remarkably, c-Myc deletion completely abrogated the immediate wave of apoptosis following both ionizing irradiation and cisplatin treatment, recapitulating the phenotype of p53 deficiency in the intestine. Consistent with this, c-Myc-deficient intestinal enterocytes did not upregulate p53. Mechanistically, this was linked to an upregulation of the E3 Ubiquitin ligase Mdm2, which targets p53 for degradation in c-Myc-deficient intestinal enterocytes. Further, low level overexpression of c-Myc, which does not impact on basal levels of apoptosis, elicited sustained apoptosis in response to DNA damage, suggesting c-Myc activity acts as a crucial cell survival rheostat following DNA damage. We also identify the importance of MYC during DNA damage-induced apoptosis in several other tissues, including the thymus and spleen, using systemic deletion of c-Myc throughout the adult mouse. Together, we have elucidated for the first time in vivo an essential role for endogenous c-Myc in signalling DNA damage-induced apoptosis through the control of the p53 tumour suppressor protein.

  4. A therapeutic role for targeting c-Myc/Hif-1-dependent signaling pathways.

    Science.gov (United States)

    Podar, Klaus; Anderson, Kenneth C

    2010-05-01

    Deregulated c-Myc occurs in approximately 30% of human cancers. Similarly, hypoxia-inducible factor (HIF) is commonly overexpressed in a variety of human malignancies. Under physiologic conditions, HIF inhibits c-Myc activity; however, when deregulated oncogenic c-Myc collaborates with HIF in inducing the expression of VEGF, PDK1 and hexokinase 2. Most of the knowledge of HIF derives from studies investigating a role of HIF under hypoxic conditions, however, HIF-1alpha stabilization is also found in normoxic conditions. Specifically, under hypoxic conditions HIF-1-mediated regulation of oncogenic c-Myc plays a pivotal role in conferring metabolic advantages to tumor cells as well as adaptation to the tumorigenic micromilieu. In addition, our own results show that under normoxic conditions oncogenic c-Myc is required for constitutive high HIF-1 protein levels and activity in Multiple Myeloma (MM) cells, thereby influencing VEGF secretion and angiogenic activity within the bone marrow microenvironment. Further studies are needed to delineate the functional relevance of HIF, MYC, and the HIF-MYC collaboration in MM and other malignancies, also integrating the tumor microenvironment and the cellular context. Importantly, early studies already demonstrate promising preclinical of novel agents, predominantly small molecules, which target c-Myc, HIF or both.

  5. Differential regulation of the c-Myc/Lin28 axis discriminates subclasses of rearranged MLL leukemia

    Science.gov (United States)

    Chen, Lili; Sun, Yuqing; Wang, Jingya; Jiang, Hui; Muntean, Andrew G.

    2016-01-01

    MLL rearrangements occur in myeloid and lymphoid leukemias and are generally associated with a poor prognosis, however this varies depending on the fusion partner. We modeled acute myeloid leukemia (AML) in mice using various MLL fusion proteins (MLL-FPs) and observed significantly different survival outcomes. To better understand the differences between these leukemias, we examined the genome wide expression profiles of leukemic cells transformed with different MLL-FPs. RNA-sequencing and pathway analysis identified the c-Myc transcriptional program as one of the top distinguishing features. c-Myc protein levels were highly correlative with AML disease latency in mice. Functionally, overexpression of c-Myc resulted in a more aggressive proliferation rate in MLL-FP cell lines. While all MLL-FP transformed cells displayed sensitivity to BET inhibitors, high c-Myc expressing cells showed greater resistance to Brd4 inhibition. The Myc target Lin28B was also differentially expressed in MLL-FP cell lines in agreement with c-Myc expression. Examination of Lin28B miRNAs targets revealed that let-7g was significantly increased in leukemic cells associated with the longest disease latency and forced let-7g expression induced differentiation of leukemic blasts. Thus, differential regulation of the c-Myc/Lin28/let-7g program by different MLL-FPs is functionally related to disease latency and BET inhibitor resistance in MLL leukemias. PMID:27007052

  6. Therapeutic aspects of c-MYC signaling in inflammatory and cancerous colonic diseases.

    Science.gov (United States)

    Sipos, Ferenc; Firneisz, Gábor; Műzes, Györgyi

    2016-09-21

    Colonic inflammation is required to heal infections, wounds, and maintain tissue homeostasis. As the seventh hallmark of cancer, however, it may affect all phases of tumor development, including tumor initiation, promotion, invasion and metastatic dissemination, and also evasion immune surveillance. Inflammation acts as a cellular stressor and may trigger DNA damage or genetic instability, and, further, chronic inflammation can provoke genetic mutations and epigenetic mechanisms that promote malignant cell transformation. Both sporadical and colitis-associated colorectal carcinogenesis are multi-step, complex processes arising from the uncontrolled proliferation and spreading of malignantly transformed cell clones with the obvious ability to evade the host's protective immunity. In cells upon DNA damage several proto-oncogenes, including c-MYC are activated in parelell with the inactivation of tumor suppressor genes. The target genes of the c-MYC protein participate in different cellular functions, including cell cycle, survival, protein synthesis, cell adhesion, and micro-RNA expression. The transcriptional program regulated by c-MYC is context dependent, therefore the final cellular response to elevated c-MYC levels may range from increased proliferation to augmented apoptosis. Considering physiological intestinal homeostasis, c-MYC displays a fundamental role in the regulation of cell proliferation and crypt cell number. However, c-MYC gene is frequently deregulated in inflammation, and overexpressed in both sporadic and colitis-associated colon adenocarcinomas. Recent results demonstrated that endogenous c-MYC is essential for efficient induction of p53-dependent apoptosis following DNA damage, but c-MYC function is also involved in and regulated by autophagy-related mechanisms, while its expression is affected by DNA-methylation, or histone acetylation. Molecules directly targeting c-MYC, or agents acting on other genes involved in the c-MYC pathway could be

  7. Therapeutic aspects of c-MYC signaling in inflammatory and cancerous colonic diseases

    Science.gov (United States)

    Sipos, Ferenc; Firneisz, Gábor; Műzes, Györgyi

    2016-01-01

    Colonic inflammation is required to heal infections, wounds, and maintain tissue homeostasis. As the seventh hallmark of cancer, however, it may affect all phases of tumor development, including tumor initiation, promotion, invasion and metastatic dissemination, and also evasion immune surveillance. Inflammation acts as a cellular stressor and may trigger DNA damage or genetic instability, and, further, chronic inflammation can provoke genetic mutations and epigenetic mechanisms that promote malignant cell transformation. Both sporadical and colitis-associated colorectal carcinogenesis are multi-step, complex processes arising from the uncontrolled proliferation and spreading of malignantly transformed cell clones with the obvious ability to evade the host’s protective immunity. In cells upon DNA damage several proto-oncogenes, including c-MYC are activated in parelell with the inactivation of tumor suppressor genes. The target genes of the c-MYC protein participate in different cellular functions, including cell cycle, survival, protein synthesis, cell adhesion, and micro-RNA expression. The transcriptional program regulated by c-MYC is context dependent, therefore the final cellular response to elevated c-MYC levels may range from increased proliferation to augmented apoptosis. Considering physiological intestinal homeostasis, c-MYC displays a fundamental role in the regulation of cell proliferation and crypt cell number. However, c-MYC gene is frequently deregulated in inflammation, and overexpressed in both sporadic and colitis-associated colon adenocarcinomas. Recent results demonstrated that endogenous c-MYC is essential for efficient induction of p53-dependent apoptosis following DNA damage, but c-MYC function is also involved in and regulated by autophagy-related mechanisms, while its expression is affected by DNA-methylation, or histone acetylation. Molecules directly targeting c-MYC, or agents acting on other genes involved in the c-MYC pathway could be

  8. c-Myc directly regulates the transcription of the NBS1 gene involved in DNA double-strand break repair.

    Science.gov (United States)

    Chiang, Yu-Chi; Teng, Shu-Chun; Su, Yi-Ning; Hsieh, Fon-Jou; Wu, Kou-Juey

    2003-05-23

    The c-myc proto-oncogene encodes a ubiquitous transcription factor involved in the control of cell growth and implicated in inducing tumorigenesis. Understanding the function of c-Myc and its role in cancer depends upon the identification of c-Myc target genes. Nijmegen breakage syndrome (NBS) is a chromosomal-instability syndrome associated with cancer predisposition, radiosensitivity, and chromosomal instability. The NBS gene product, NBS1 (p95 or nibrin), is a part of the hMre11 complex, a central player associated with double-strand break (DSB) repair. NBS1 contains domains characteristic for proteins involved in DNA repair, recombination, and replication. Here we show that c-Myc directly activates NBS1. c-Myc-mediated induction of NBS1 gene transcription occurs in different tissues, is independent of cell proliferation, and is mediated by a c-Myc binding site in the intron 1 region of NBS1 gene. Overexpression of NBS1 in Rat1a cells increased cell proliferation. These results indicate that NBS1 is a direct transcriptional target of c-Myc and links the function of c-Myc to the regulation of DNA DSB repair pathway operating during DNA replication.

  9. Acidosis Decreases c-Myc Oncogene Expression in Human Lymphoma Cells: A Role for the Proton-Sensing G Protein-Coupled Receptor TDAG8

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-10-01

    Full Text Available Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65 is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs. Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression.

  10. Cooverexpression of EpCAM and c-myc genes in malignant breast tumours

    Indian Academy of Sciences (India)

    SAMIRA SADEGHI; ZOHREH HOJATI; HOSSEIN TABATABAEIAN

    2017-03-01

    The overexpression of epithelial cell adhesion molecule (EpCAM), a proto-oncogene, affects progression, treatment, and diagnosis of many adenocarcinomas. C-myc has been shown to be a downstream target of EpCAM and is also one of the most important proto-oncogenes routinely overexpressed in breast cancer. However, cooverexpression of EpCAM and c-mycgenes has not been investigated in breast cancer tissues, particularly in Iranian population. The aim of this study was to assess the expression of EpCAM and c-myc genes in malignant breast cancer tissues using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) followed by analyses of the association between the outcomes. In this study, 122 fresh tissues, including 104 malignant and 18 benign samples, were disrupted by mortar and pestle, and then the RNA was isolated from the samples and converted to cDNA. The relative expression levels of EpCAM and c-myc genes were measured by2−ΔΔCt method using RT-qPCR. EpCAM protein level was also assessed in 66 cases using Western blot technique. UsingRT-qPCR method, our results showed that EpCAM was overexpressed in 48% of malignant and 11.1% of benign samples. Evaluating EpCAM protein overexpression in a portion of samples depicted the fully concordance rate between Western blot and RT-qPCR techniques. C-myc expression was first evaluated by RT-qPCR method, showing the overexpression rate of 39%and 28% in malignant and benign samples, respectively. These data were also quite concordant with the clinically available immunohistochemistry reports of the same samples studied in this study. Importantly, overexpression of EpCAM and c-myc was significantly associated and showed an agreement of 57.3%. This study demonstrated the cooverexpression of EpCAM and c-myc in breast tumours collected from breast cancer patients of the Iranian population. EpCAM and c-myc positive cases were significantly associated with reduced and enhanced risk of ER/PR positivity

  11. c-myc null cells misregulate cad and gadd45 but not other proposed c-Myc targets

    Science.gov (United States)

    Bush, Andrew; Mateyak, Maria; Dugan, Kerri; Obaya, Alvaro; Adachi, Susumu; Sedivy, John; Cole, Michael

    1998-01-01

    We report here that the expression of virtually all proposed c-Myc target genes is unchanged in cells containing a homozygous null deletion of c-myc. Two noteworthy exceptions are the gene cad, which has reduced log phase expression and serum induction in c-myc null cells, and the growth arrest gene gadd45, which is derepressed by c-myc knockout. Thus, cad and gadd45 are the only proposed targets of c-Myc that may contribute to the dramatic slow growth phenotype of c-myc null cells. Our results demonstrate that a loss-of-function approach is critical for the evaluation of potential c-Myc target genes. PMID:9869632

  12. Cooperation of Gata3, c-Myc and Notch in malignant transformation of double positive thymocytes.

    Science.gov (United States)

    van Hamburg, Jan Piet; de Bruijn, Marjolein J W; Dingjan, Gemma M; Beverloo, H Berna; Diepstraten, Hans; Ling, Kam-Wing; Hendriks, Rudi W

    2008-06-01

    Gata transcription factors are critical regulators of proliferation and differentiation implicated in various human cancers, but specific genes activated by Gata proteins remain to be identified. We previously reported that enforced expression of Gata3 during T cell development in CD2-Gata3 transgenic mice induced CD4(+)CD8(+) double-positive (DP) T cell lymphoma. Here, we show that the presence of the DO11.10 T-cell receptor transgene, which directs DP cells towards the CD4 lineage, resulted in enhanced lymphoma development and a dramatic increase in thymocyte cell size in CD2-Gata3 transgenic mice. CD2-Gata3 DP cells expressed high levels of the proto-oncogene c-Myc but the Notch1 signaling pathway, which is known to induce c-Myc, was not activated. Gene expression profiling showed that in CD2-Gata3 lymphoma cells transcription of c-Myc and its target genes was further increased. A substantial fraction of CD2-Gata3 lymphomas had trisomy of chromosome 15, leading to an increased c-Myc gene dose. Interestingly, most lymphomas showed high expression of the Notch targets Deltex1 and Hes1, often due to activating Notch1 PEST domain mutations. Therefore, we conclude that enforced Gata3 expression converts DP thymocytes into a pre-malignant state, characterized by high c-Myc expression, whereby subsequent induction of Notch1 signaling cooperates to establish malignant transformation. The finding that Gata3 regulates c-Myc expression levels, in a direct or indirect fashion, may explain the parallel phenotypes of mice with overexpression or deficiency of either of the two transcription factors.

  13. A proteomic study of cMyc improvement of CHO culture

    Directory of Open Access Journals (Sweden)

    Dunn Michael J

    2010-03-01

    Full Text Available Abstract Background The biopharmaceutical industry requires cell lines to have an optimal proliferation rate and a high integral viable cell number resulting in a maximum volumetric recombinant protein product titre. Nutrient feeding has been shown to boost cell number and productivity in fed-batch culture, but cell line engineering is another route one may take to increase these parameters in the bioreactor. The use of CHO-K1 cells with a c-myc plasmid allowing for over-expressing c-Myc (designated cMycCHO gives a higher integral viable cell number. In this study the differential protein expression in cMycCHO is investigated using two-dimensional gel electrophoresis (2-DE followed by image analysis to determine the extent of the effect c-Myc has on the cell and the proteins involved to give the new phenotype. Results Over 100 proteins that were differentially expressed in cMycCHO cells were detected with high statistical confidence, of which 41 were subsequently identified by tandem mass spectrometry (LC-MS/MS. Further analysis revealed proteins involved in a variety of pathways. Some examples of changes in protein expression include: an increase in nucleolin, involved in proliferation and known to aid in stabilising anti-apoptotic protein mRNA levels, the cytoskeleton and mitochondrial morphology (vimentin, protein biosysnthesis (eIF6 and energy metabolism (ATP synthetase, and a decreased regulation of all proteins, indentified, involved in matrix and cell to cell adhesion. Conclusion These results indicate several proteins involved in proliferation and adhesion that could be useful for future approaches to improve proliferation and decrease adhesion of CHO cell lines which are difficult to adapt to suspension culture.

  14. Functional analysis of Burkitt's lymphoma mutant c-Myc proteins

    OpenAIRE

    1996-01-01

    The c-myc gene encodes a sequence-specific DNA binding protein that activates transcription of cellular genes. Transcription activation by Myc proteins is regulated by phosphorylation of serine and threonine residues within the transactivation domain and by complex formation with the retinoblastoma-related protein p107. In Burkitt’s lymphoma, missense mutations within the c-Myc transactivation domain have been found with high frequency. It has been reported that mutant c-Myc proteins derived ...

  15. C-Myc negatively controls the tumor suppressor PTEN by upregulating miR-26a in glioblastoma multiforme cells

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Pin; Nie, Quanmin; Lan, Jin; Ge, Jianwei [Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Qiu, Yongming, E-mail: qiuzhoub@hotmail.com [Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Shanghai Institute of Head Trauma, Shanghai 200127 (China); Mao, Qing, E-mail: maoq@netease.com [Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127 (China); Shanghai Institute of Head Trauma, Shanghai 200127 (China)

    2013-11-08

    Highlights: •The c-Myc oncogene directly upregulates miR-26a expression in GBM cells. •ChIP assays demonstrate that c-Myc interacts with the miR-26a promoter. •Luciferase reporter assays show that PTEN is a specific target of miR-26a. •C-Myc–miR-26a suppression of PTEN may regulate the PTEN/AKT pathway. •Overexpression of c-Myc enhances the proliferative capacity of GBM cells. -- Abstract: The c-Myc oncogene is amplified in many tumor types. It is an important regulator of cell proliferation and has been linked to altered miRNA expression, suggesting that c-Myc-regulated miRNAs might contribute to tumor progression. Although miR-26a has been reported to be upregulated in glioblastoma multiforme (GBM), the mechanism has not been established. We have shown that ectopic expression of miR-26a influenced cell proliferation by targeting PTEN, a tumor suppressor gene that is inactivated in many common malignancies, including GBM. Our findings suggest that c-Myc modulates genes associated with oncogenesis in GBM through deregulation of miRNAs via the c-Myc–miR-26a–PTEN signaling pathway. This may be of clinical relevance.

  16. Prognostic Value of Beta-Tubulin-3 and c-Myc in Muscle Invasive Urothelial Carcinoma of the Bladder

    Science.gov (United States)

    Massari, Francesco; Bria, Emilio; Ciccarese, Chiara; Munari, Enrico; Modena, Alessandra; Zambonin, Valentina; Sperduti, Isabella; Artibani, Walter; Cheng, Liang; Martignoni, Guido; Tortora, Giampaolo; Brunelli, Matteo

    2015-01-01

    Background To date, putative prognostic biomarkers have shown limited utility from the clinical perspective for bladder urothelial carcinoma. Herein, the expression of beta-tubulin-3 and c-Myc was evaluated to determine their prognostic potential. Methods In formalin fixed-paraffin embedded blocks, immunohistochemical expression of c-Myc and beta-tubulin-3 was evaluated. H score ranging from 0 to 300 was obtained by multiplying the percentage of positive cells by intensity (0–3); c-Myc and beta-tubulin-3 expression was defined: 0: negative, 1: weakly positive, 2: strongly positive. Results beta-tubulin-3 and c-Myc immunoexpression was available for 46 cases. At the univariate analysis, node-involvement, beta-tubulin-3 and c-Myc overexpression discriminate shorter DFS (HR 2.19, p = 0.043; HR 3.10, p = 0.24 and HR 3.05, p = 0.011, respectively); 2-yrs DFS log-rank analysis according to low versus high level of immunoexpression were statistically significant; beta-tubulin-3, 53% low vs 12.7% high (p = value 0.02) and c-Myc 28 low vs 8 high (p-value 0.007). Patients displaying negative beta-tubulin-3/c-Myc had statistically significant better 2-yrs DFS than those with mixed expression or double positivity (54.5% versus 18.7% versus 0%, log-rank p = 0.006). Conclusions c-Myc and beta-tubulin-3 show improvement for prognostic risk stratification in patients with muscle invasive bladder urothelial carcinoma. These molecular pathways may also be candidate to improve predictiveness to targeted therapies. PMID:26046361

  17. Prognostic Value of Beta-Tubulin-3 and c-Myc in Muscle Invasive Urothelial Carcinoma of the Bladder.

    Directory of Open Access Journals (Sweden)

    Francesco Massari

    Full Text Available To date, putative prognostic biomarkers have shown limited utility from the clinical perspective for bladder urothelial carcinoma. Herein, the expression of beta-tubulin-3 and c-Myc was evaluated to determine their prognostic potential.In formalin fixed-paraffin embedded blocks, immunohistochemical expression of c-Myc and beta-tubulin-3 was evaluated. H score ranging from 0 to 300 was obtained by multiplying the percentage of positive cells by intensity (0-3; c-Myc and beta-tubulin-3 expression was defined: 0: negative, 1: weakly positive, 2: strongly positive.beta-tubulin-3 and c-Myc immunoexpression was available for 46 cases. At the univariate analysis, node-involvement, beta-tubulin-3 and c-Myc overexpression discriminate shorter DFS (HR 2.19, p = 0.043; HR 3.10, p = 0.24 and HR 3.05, p = 0.011, respectively; 2-yrs DFS log-rank analysis according to low versus high level of immunoexpression were statistically significant; beta-tubulin-3, 53% low vs 12.7% high (p = value 0.02 and c-Myc 28 low vs 8 high (p-value 0.007. Patients displaying negative beta-tubulin-3/c-Myc had statistically significant better 2-yrs DFS than those with mixed expression or double positivity (54.5% versus 18.7% versus 0%, log-rank p = 0.006.c-Myc and beta-tubulin-3 show improvement for prognostic risk stratification in patients with muscle invasive bladder urothelial carcinoma. These molecular pathways may also be candidate to improve predictiveness to targeted therapies.

  18. c-Myc regulates cell proliferation during lens development.

    Directory of Open Access Journals (Sweden)

    Gabriel R Cavalheiro

    Full Text Available Myc protooncogenes play important roles in the regulation of cell proliferation, growth, differentiation and survival during development. In various developing organs, c-myc has been shown to control the expression of cell cycle regulators and its misregulated expression is detected in many human tumors. Here, we show that c-myc gene (Myc is highly expressed in developing mouse lens. Targeted deletion of c-myc gene from head surface ectoderm dramatically impaired ocular organogenesis, resulting in severe microphtalmia, defective anterior segment development, formation of a lens stalk and/or aphakia. In particular, lenses lacking c-myc presented thinner epithelial cell layer and growth impairment that was detectable soon after its inactivation. Defective development of c-myc-null lens was not caused by increased cell death of lens progenitor cells. Instead, c-myc loss reduced cell proliferation, what was associated with an ectopic expression of Prox1 and p27(Kip1 proteins within epithelial cells. Interestingly, a sharp decrease in the expression of the forkhead box transcription factor Foxe3 was also observed following c-myc inactivation. These data represent the first description of the physiological roles played by a Myc family member in mouse lens development. Our findings support the conclusion that c-myc regulates the proliferation of lens epithelial cells in vivo and may, directly or indirectly, modulate the expression of classical cell cycle regulators in developing mouse lens.

  19. C-Myc regulation by costimulatory signals modulates the generation of CD8+ memory T cells during viral infection.

    Science.gov (United States)

    Haque, Mohammad; Song, Jianyong; Fino, Kristin; Wang, Youfei; Sandhu, Praneet; Song, Xinmeng; Norbury, Christopher; Ni, Bing; Fang, Deyu; Salek-Ardakani, Shahram; Song, Jianxun

    2016-01-01

    The signalling mechanisms of costimulation in the development of memory T cells remain to be clarified. Here, we show that the transcription factor c-Myc in CD8(+) T cells is controlled by costimulatory molecules, which modulates the development of memory CD8(+) T cells. C-Myc expression was dramatically reduced in Cd28(-/-) or Ox40(-/-) memory CD8(+) T cells, and c-Myc over-expression substantially reversed the defects in the development of T-cell memory following viral infection. C-Myc regulated the expression of survivin, an inhibitor of apoptosis, which promoted the generation of virus-specific memory CD8(+) T cells. Moreover, over-expression of survivin with bcl-xL, a downstream molecule of NF-κB and intracellular target of costimulation that controls survival, in Cd28(-/-) or Ox40(-/-) CD8(+) T cells, reversed the defects in the generation of memory T cells in response to viral infection. These results identify c-Myc as a key controller of memory CD8(+) T cells from costimulatory signals.

  20. Interaction of c-Myc with the pRb-related protein p107 results in inhibition of c-Myc-mediated transactivation

    NARCIS (Netherlands)

    Beijersbergen, R.L.; Hijmans, E.M.; Zhu, L.; Bernards, R.A.

    1994-01-01

    The product of the c-myc proto-oncogene, c-Myc, is a sequence-specific DNA binding protein with an Nterminal transactivation domain and a C-terminal DNA binding domain. Several lines of evidence indicate that c-Myc activity is essential for normal cell cycle progression. Since the abundance of c-Myc

  1. Global regulation of nucleotide biosynthetic genes by c-Myc.

    Directory of Open Access Journals (Sweden)

    Yen-Chun Liu

    Full Text Available BACKGROUND: The c-Myc transcription factor is a master regulator and integrates cell proliferation, cell growth and metabolism through activating thousands of target genes. Our identification of direct c-Myc target genes by chromatin immunoprecipitation (ChIP coupled with pair-end ditag sequencing analysis (ChIP-PET revealed that nucleotide metabolic genes are enriched among c-Myc targets, but the role of Myc in regulating nucleotide metabolic genes has not been comprehensively delineated. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that the majority of genes in human purine and pyrimidine biosynthesis pathway were induced and directly bound by c-Myc in the P493-6 human Burkitt's lymphoma model cell line. The majority of these genes were also responsive to the ligand-activated Myc-estrogen receptor fusion protein, Myc-ER, in a Myc null rat fibroblast cell line, HO.15 MYC-ER. Furthermore, these targets are also responsive to Myc activation in transgenic mouse livers in vivo. To determine the functional significance of c-Myc regulation of nucleotide metabolism, we sought to determine the effect of loss of function of direct Myc targets inosine monophosphate dehydrogenases (IMPDH1 and IMPDH2 on c-Myc-induced cell growth and proliferation. In this regard, we used a specific IMPDH inhibitor mycophenolic acid (MPA and found that MPA dramatically inhibits c-Myc-induced P493-6 cell proliferation through S-phase arrest and apoptosis. CONCLUSIONS/SIGNIFICANCE: Taken together, these results demonstrate the direct induction of nucleotide metabolic genes by c-Myc in multiple systems. Our finding of an S-phase arrest in cells with diminished IMPDH activity suggests that nucleotide pool balance is essential for c-Myc's orchestration of DNA replication, such that uncoupling of these two processes create DNA replication stress and apoptosis.

  2. Targeting angiogenesis via a c-Myc/hypoxia-inducible factor-1alpha-dependent pathway in multiple myeloma.

    Science.gov (United States)

    Zhang, Jing; Sattler, Martin; Tonon, Giovanni; Grabher, Clemens; Lababidi, Samir; Zimmerhackl, Alexander; Raab, Marc S; Vallet, Sonia; Zhou, Yiming; Cartron, Marie-Astrid; Hideshima, Teru; Tai, Yu-Tzu; Chauhan, Dharminder; Anderson, Kenneth C; Podar, Klaus

    2009-06-15

    Bone marrow angiogenesis is associated with multiple myeloma (MM) progression. Here, we report high constitutive hypoxia-inducible factor-1alpha (Hif-1alpha) expression in MM cells, which is associated with oncogenic c-Myc. A drug screen for anti-MM agents that decrease Hif-1alpha and c-Myc levels identified a variety of compounds, including bortezomib, lenalidomide, enzastaurin, and adaphostin. Functionally, based on transient knockdowns and overexpression, our data delineate a c-Myc/Hif-1alpha-dependent pathway mediating vascular endothelial growth factor production and secretion. The antiangiogenic activity of our tool compound, adaphostin, was subsequently shown in a zebrafish model and translated into a preclinical in vitro and in vivo model of MM in the bone marrow milieu. Our data, therefore, identify Hif-1alpha as a novel molecular target in MM and add another facet to anti-MM drug activity.

  3. Analysis of secretome changes uncovers an autocrine/paracrine component in the modulation of cell proliferation and motility by c-Myc.

    Science.gov (United States)

    Pocsfalvi, Gabriella; Votta, Giuseppina; De Vincenzo, Anna; Fiume, Immacolata; Raj, Delfin Albert Amal; Marra, Giancarlo; Stoppelli, Maria Patrizia; Iaccarino, Ingram

    2011-12-02

    Proteins secreted by cancer cells are a major component of tumor microenvironment. However, little is known on the impact of single oncogenic lesions on the expression of secreted proteins at early stages of tumor development. Because c-Myc overexpression is among the most frequent alterations in cancer, here we investigated the effect of sustained c-Myc expression on the secretome of a nontransformed human epithelial cell line (hT-RPE). By using a quantitative proteomic approach, we have identified 125 proteins in conditioned media of hT-RPE/MycER cells upon c-Myc induction. Analysis of the 49 proteins significantly down-regulated by c-Myc revealed a marked enrichment of factors associated with growth inhibition and cellular senescence. Accordingly, media conditioned by hT-RPE cells expressing c-Myc show an increased ability to sustain hT-RPE cellular proliferation/viability. We also find a marked down-regulation of several structural and regulatory components of the extracellular matrix (ECM), which correlates with an increased chemotactic potency of the conditioned media toward fibroblasts, a major cellular component of tumor stroma. In accordance with these data, the expression of the majority of the genes encoding proteins down-regulated in hT-RPE was significantly reduced also in colorectal adenomatous polyps, early tumors in which c-Myc is invariably overexpressed. These findings help to elucidate the significance of c-Myc overexpression at early stages of tumor development and uncover a remarkable autocrine/paracrine component in the ability of c-Myc to stimulate proliferation, sustain tumor maintenance, and modulate cell migration.

  4. Dose-dependent regulation of target gene expression and cell proliferation by c-Myc levels.

    Science.gov (United States)

    Schuhmacher, Marino; Eick, Dirk

    2013-01-01

    The proto-oncogene c-myc encodes a basic helix-loop-helix leucine zipper transcription factor (c-Myc). c-Myc plays a crucial role in cell growth and proliferation. Here, we examined how expression of c-Myc target genes and cell proliferation depend on variation of c-Myc protein levels. We show that proliferation rates, the number of cells in S-phase, and cell size increased in a dose-dependent manner in response to increasing c-Myc levels. Likewise, the mRNA levels of c-Myc responsive genes steadily increased with rising c-Myc levels. Strikingly, steady-state mRNA levels of c-Myc target genes did not saturate even at highest c-Myc concentrations. These characteristics predestine c-Myc levels as a cellular rheostat for the control and fine-tuning of cell proliferation and growth rates.

  5. Alterations of c-Myc and c-erbB-2 genes in ovarian tumours

    Directory of Open Access Journals (Sweden)

    Pastor Tibor

    2009-01-01

    Full Text Available Introduction. According to clinical and epidemiological studies, ovarian cancer ranks fifth in cancer deaths among women. The causes of ovarian cancer remain largely unknown but various factors may increase the risk of developing it, such as age, family history of cancer, childbearing status etc. This cancer results from a succession of genetic alterations involving oncogenes and tumour suppressor genes, which have a critical role in normal cell growth regulation. Mutations and/or overexpression of three oncogenes, c-erbB-2, c-Myc and K-ras, and of the tumour suppressor gene p53, have been frequently observed in a sporadic ovarian cancer. Objective. The aim of the present study was to analyze c-Myc and c-erbB-2 oncogene alterations, specifically amplification, as one of main mechanisms of their activation in ovarian cancers and to establish a possible association with the pathogenic process. Methods. DNA was isolated from 15 samples of malignant and 5 benign ovarian tumours, using proteinase K digestion, followed by phenol-chloroform isoamyl extraction and ethanol precipitation. C-Myc and c-erbB-2 amplification were detected by differential PCR. The level of gene copy increase was measured using the Scion image software. Results. The amplification of both c-Myc and c-erbB-2 was detected in 26.7% of ovarian epithelial carcinoma specimens. Only one tumour specimen concomitantly showed increased gene copy number for both studied genes. Interestingly, besides amplification, gene deletion was also detected (26.7% for c-erbB-2. Most of the ovarian carcinomas with alterations in c-Myc and c-erbB-2 belonged to advanced FIGO stages. Conclusion. The amplification of c-Myc and c-erbB-2 oncogenes in ovarian epithelial carcinomas is most probably a late event in the pathogenesis conferring these tumours a more aggressive biological behaviour. Similarly, gene deletions point to genomic instability in epithelial carcinomas in higher clinical stages as the

  6. Long-range oncogenic activation of Igh-c-myc translocations by the Igh 3' regulatory region.

    Science.gov (United States)

    Gostissa, Monica; Yan, Catherine T; Bianco, Julia M; Cogné, Michel; Pinaud, Eric; Alt, Frederick W

    2009-12-10

    B-cell malignancies, such as human Burkitt's lymphoma, often contain translocations that link c-myc or other proto-oncogenes to the immunoglobulin heavy chain locus (IgH, encoded by Igh). The nature of elements that activate oncogenes within such translocations has been a long-standing question. Translocations within Igh involve DNA double-strand breaks initiated either by the RAG1/2 endonuclease during variable, diversity and joining gene segment (V(D)J) recombination, or by activation-induced cytidine deaminase (AID, also known as AICDA) during class switch recombination (CSR). V(D)J recombination in progenitor B (pro-B) cells assembles Igh variable region exons upstream of mu constant region (Cmu) exons, which are the first of several sets of C(H) exons ('C(H) genes') within a C(H) locus that span several hundred kilobases (kb). In mature B cells, CSR deletes Cmu and replaces it with a downstream C(H) gene. An intronic enhancer (iEmu) between the variable region exons and Cmu promotes V(D)J recombination in developing B cells. Furthermore, the Igh 3' regulatory region (Igh3'RR) lies downstream of the C(H) locus and modulates CSR by long-range transcriptional enhancement of C(H) genes. Transgenic mice bearing iEmu or Igh3'RR sequences fused to c-myc are predisposed to B lymphomas, demonstrating that such elements can confer oncogenic c-myc expression. However, in many B-cell lymphomas, Igh-c-myc translocations delete iEmu and place c-myc up to 200 kb upstream of the Igh3'RR. Here we address the oncogenic role of the Igh3'RR by inactivating it in two distinct mouse models for B-cell lymphoma with Igh-c-myc translocations. We show that the Igh3'RR is dispensable for pro-B-cell lymphomas with V(D)J recombination-initiated translocations, but is required for peripheral B-cell lymphomas with CSR-associated translocations. As the Igh3'RR is not required for CSR-associated Igh breaks or Igh-c-myc translocations in peripheral B-cell lymphoma progenitors, we conclude that

  7. Targeting of the MYCN protein with small molecule c-MYC inhibitors.

    Directory of Open Access Journals (Sweden)

    Inga Müller

    Full Text Available Members of the MYC family are the most frequently deregulated oncogenes in human cancer and are often correlated with aggressive disease and/or poorly differentiated tumors. Since patients with MYCN-amplified neuroblastoma have a poor prognosis, targeting MYCN using small molecule inhibitors could represent a promising therapeutic approach. We have previously demonstrated that the small molecule 10058-F4, known to bind to the c-MYC bHLHZip dimerization domain and inhibiting the c-MYC/MAX interaction, also interferes with the MYCN/MAX dimerization in vitro and imparts anti-tumorigenic effects in neuroblastoma tumor models with MYCN overexpression. Our previous work also revealed that MYCN-inhibition leads to mitochondrial dysfunction resulting in accumulation of lipid droplets in neuroblastoma cells. To expand our understanding of how small molecules interfere with MYCN, we have now analyzed the direct binding of 10058-F4, as well as three of its analogs; #474, #764 and 10058-F4(7RH, one metabolite C-m/z 232, and a structurally unrelated c-MYC inhibitor 10074-G5, to the bHLHZip domain of MYCN. We also assessed their ability to induce apoptosis, neurite outgrowth and lipid accumulation in neuroblastoma cells. Interestingly, all c-MYC binding molecules tested also bind MYCN as assayed by surface plasmon resonance. Using a proximity ligation assay, we found reduced interaction between MYCN and MAX after treatment with all molecules except for the 10058-F4 metabolite C-m/z 232 and the non-binder 10058-F4(7RH. Importantly, 10074-G5 and 10058-F4 were the most efficient in inducing neuronal differentiation and lipid accumulation in MYCN-amplified neuroblastoma cells. Together our data demonstrate MYCN-binding properties for a selection of small molecules, and provide functional information that could be of importance for future development of targeted therapies against MYCN-amplified neuroblastoma.

  8. SIRT1 Limits Adipocyte Hyperplasia through c-Myc Inhibition.

    Science.gov (United States)

    Abdesselem, Houari; Madani, Aisha; Hani, Ahmad; Al-Noubi, Muna; Goswami, Neha; Ben Hamidane, Hisham; Billing, Anja M; Pasquier, Jennifer; Bonkowski, Michael S; Halabi, Najeeb; Dalloul, Rajaa; Sheriff, Mohamed Z; Mesaeli, Nasrin; ElRayess, Mohamed; Sinclair, David A; Graumann, Johannes; Mazloum, Nayef A

    2016-01-29

    The expansion of fat mass in the obese state is due to increased adipocyte hypertrophy and hyperplasia. The molecular mechanism that drives adipocyte hyperplasia remains unknown. The NAD(+)-dependent protein deacetylase sirtuin 1 (SIRT1), a key regulator of mammalian metabolism, maintains proper metabolic functions in many tissues, counteracting obesity. Here we report that differentiated adipocytes are hyperplastic when SIRT1 is knocked down stably in mouse 3T3-L1 preadipocytes. This phenotype is associated with dysregulated adipocyte metabolism and enhanced inflammation. We also demonstrate that SIRT1 is a key regulator of proliferation in preadipocytes. Quantitative proteomics reveal that the c-Myc pathway is altered to drive enhanced proliferation in SIRT1-silenced 3T3-L1 cells. Moreover, c-Myc is hyperacetylated, levels of p27 are reduced, and cyclin-dependent kinase 2 (CDK2) is activated upon SIRT1 reduction. Remarkably, differentiating SIRT1-silenced preadipocytes exhibit enhanced mitotic clonal expansion accompanied by reduced levels of p27 as well as elevated levels of CCAAT/enhancer-binding protein β (C/EBPβ) and c-Myc, which is also hyperacetylated. c-Myc activation and enhanced proliferation phenotype are also found to be SIRT1-dependent in proliferating mouse embryonic fibroblasts and differentiating human SW872 preadipocytes. Reducing both SIRT1 and c-Myc expression in 3T3-L1 cells simultaneously does not induce the adipocyte hyperplasia phenotype, confirming that SIRT1 controls adipocyte hyperplasia through c-Myc regulation. A better understanding of the molecular mechanisms of adipocyte hyperplasia will open new avenues toward understanding obesity.

  9. Decoding c-Myc networks of cell cycle and apoptosis regulated genes in a transgenic mouse model of papillary lung adenocarcinomas.

    Science.gov (United States)

    Ciribilli, Yari; Singh, Prashant; Spanel, Reinhard; Inga, Alberto; Borlak, Jürgen

    2015-10-13

    The c-Myc gene codes for a basic-helix-loop-helix-leucine zipper transcription factor protein and is reported to be frequently over-expressed in human cancers. Given that c-Myc plays an essential role in neoplastic transformation we wished to define its activity in lung cancer and therefore studied its targeted expression to respiratory epithelium in a transgenic mouse disease model. Using histological well-defined tumors, transcriptome analysis identified novel c-Myc responsive cell cycle and apoptosis genes that were validated as direct c-Myc targets using EMSA, Western blotting, gene reporter and ChIP assays.Through computational analyses c-Myc cooperating transcription factors emerged for repressed and up-regulated genes in cancer samples, namely Klf7, Gata3, Sox18, p53 and Elf5 and Cebpα, respectively. Conversely, at promoters of genes regulated in transgenic but non-carcinomatous lung tissue enriched binding sites for c-Myc, Hbp1, Hif1 were observed. Bioinformatic analysis of tumor transcriptomic data revealed regulatory gene networks and highlighted mortalin and moesin as master regulators while gene reporter and ChIP assays in the H1299 lung cancer cell line as well as cross-examination of published ChIP-sequence data of 7 human and 2 mouse cell lines provided strong evidence for the identified genes to be c-Myc targets. The clinical significance of findings was established by evaluating expression of orthologous proteins in human lung cancer. Taken collectively, a molecular circuit for c-Myc-dependent cellular transformation was identified and the network analysis broadened the perspective for molecularly targeted therapies.

  10. c-Myc Enhances Sonic Hedgehog-Induced Medulloblastoma Formation from Nestin-Expressing Neural Progenitors in Mice

    Directory of Open Access Journals (Sweden)

    Ganesh Rao

    2003-05-01

    Full Text Available Medulloblastomas are malignant brain tumors that arise in the cerebella of children. The presumed cellsof-origin are undifferentiated precursors of granule neurons that occupy the external granule layer (EGL of the developing cerebellum. The overexpression of proteins that normally stimulate proliferation of neural progenitor cells may initiate medulloblastoma formation. Two known mitogens for neural progenitors are the c-Myc oncoprotein and Sonic hedgehog (Shh, a crucial determinant of embryonic pattern formation in the central nervous system. We modeled the ability of c-Myc and Shh to induce medulloblastoma in mice using the RCAS/tv-a system, which allows postnatal gene transfer and expression in a cell type-specific manner. We targeted the expression of Shh and c-Myc to nestin-expressing neural progenitor cells by injecting replication-competent ALV splice acceptor (RCAS vectors into the cerebella of newborn mice. Following injection with RCAS-Shh alone, 3/32 (9% mice developed medulloblastomas and 5/32 showed multifocal hyperproliferation of the EGL, possibly a precursor stage of medulloblastoma. Following injection with RCAS-Shh plus RCAS-Myc, 9/39 (23% mice developed medulloblastomas. We conclude that nestin-expressing neural progenitors, present in the cerebellum at birth, can act as the cells-of-origin for medulloblastoma, and that c-Myc cooperates with Shh to enhance tumorigenicity.

  11. Alteraciones del gen c-Myc en la oncogénesis = c-Myc gene alterations in oncogenesis

    Directory of Open Access Journals (Sweden)

    Ospina Pérez, Mariano

    2011-12-01

    Full Text Available La familia de protooncogenes MYC (c-Myc, N-Myc y L-Myc se relaciona con el origen de diversas neoplasias en seres humanos. Estos genes actúan como factores de transcripción y participan en la regulación del ciclo celular, la proliferación y diferenciación celulares, la apoptosis y la inmortalización. Los genes MYC se expresan en diferentes tejidos y responden a diversas señales internas y externas; codifican para la síntesis de factores de transcripción que se unen al ADN para regular la expresión de múltiples genes. El gen más ampliamente estudiado de esta familia es c-Myc, que se expresa en las células con mayor tasa de proli­feración. C-Myc se encuentra alterado en un gran número de tumores sólidos, leucemias y linfomas. Las alteraciones de c-Myc encontradas con mayor frecuencia en células cancero­sas son las amplificaciones, translocaciones, mutaciones y reordenamientos cromosómicos que involucran el locus de este gen y conducen a que se desregule su expresión en diversas neoplasias humanas. La amplificación de c-Myc es una alteración común en los cánceres de mama, pulmón, ovario y próstata, así como en leucemias y linfomas, mientras que la pérdida de su regulación es común en el cáncer de colon, en tumores ginecológicos y melanoma. En neoplasias con defectos de c-Myc los estudios actuales están dirigidos al desarrollo de nuevas estrategias terapéuticas.

  12. Lack of cyclin-dependent kinase 4 inhibits c-myc tumorigenic activities in epithelial tissues.

    Science.gov (United States)

    Miliani de Marval, Paula L; Macias, Everardo; Rounbehler, Robert; Sicinski, Piotr; Kiyokawa, Hiroaki; Johnson, David G; Conti, Claudio J; Rodriguez-Puebla, Marcelo L

    2004-09-01

    The proto-oncogene c-myc encodes a transcription factor that is implicated in the regulation of cellular proliferation, differentiation, and apoptosis and that has also been found to be deregulated in several forms of human and experimental tumors. We have shown that forced expression of c-myc in epithelial tissues of transgenic mice (K5-Myc) resulted in keratinocyte hyperproliferation and the development of spontaneous tumors in the skin and oral cavity. Although a number of genes involved in cancer development are regulated by c-myc, the actual mechanisms leading to Myc-induced neoplasia are not known. Among the genes regulated by Myc is the cyclin-dependent kinase 4 (CDK4) gene. Interestingly, previous studies from our laboratory showed that the overexpression of CDK4 led to keratinocyte hyperproliferation, although no spontaneous tumor development was observed. Thus, we tested the hypothesis that CDK4 may be one of the critical downstream genes involved in Myc carcinogenesis. Our results showed that CDK4 inhibition in K5-Myc transgenic mice resulted in the complete inhibition of tumor development, suggesting that CDK4 is a critical mediator of tumor formation induced by deregulated Myc. Furthermore, a lack of CDK4 expression resulted in marked decreases in epidermal thickness and keratinocyte proliferation compared to the results obtained for K5-Myc littermates. Biochemical analysis of the K5-Myc epidermis showed that CDK4 mediates the proliferative activities of Myc by sequestering p21Cip1 and p27Kip1 and thereby indirectly activating CDK2 kinase activity. These results show that CDK4 mediates the proliferative and oncogenic activities of Myc in vivo through a mechanism that involves the sequestration of specific CDK inhibitors.

  13. Guttiferone K impedes cell cycle re-entry of quiescent prostate cancer cells via stabilization of FBXW7 and subsequent c-MYC degradation.

    Science.gov (United States)

    Xi, Z; Yao, M; Li, Y; Xie, C; Holst, J; Liu, T; Cai, S; Lao, Y; Tan, H; Xu, H-X; Dong, Q

    2016-06-02

    Cell cycle re-entry by quiescent cancer cells is an important mechanism for cancer progression. While high levels of c-MYC expression are sufficient for cell cycle re-entry, the modality to block c-MYC expression, and subsequent cell cycle re-entry, is limited. Using reversible quiescence rendered by serum withdrawal or contact inhibition in PTEN(null)/p53(WT) (LNCaP) or PTEN(null)/p53(mut) (PC-3) prostate cancer cells, we have identified a compound that is able to impede cell cycle re-entry through c-MYC. Guttiferone K (GUTK) blocked resumption of DNA synthesis and preserved the cell cycle phase characteristics of quiescent cells after release from the quiescence. In vehicle-treated cells, there was a rapid increase in c-MYC protein levels upon release from the quiescence. However, this increase was inhibited in the presence of GUTK with an associated acceleration in c-MYC protein degradation. The inhibitory effect of GUTK on cell cycle re-entry was significantly reduced in cells overexpressing c-MYC. The protein level of FBXW7, a subunit of E3 ubiquitin ligase responsible for degradation of c-MYC, was reduced upon the release from the quiescence. In contrast, GUTK stabilized FBXW7 protein levels during release from the quiescence. The critical role of FBXW7 was confirmed using siRNA knockdown, which impaired the inhibitory effect of GUTK on c-MYC protein levels and cell cycle re-entry. Administration of GUTK, either in vitro prior to transplantation or in vivo, suppressed the growth of quiescent prostate cancer cell xenografts. Furthermore, elevation of FBXW7 protein levels and reduction of c-MYC protein levels were found in the xenografts of GUTK-treated compared with vehicle-treated mice. Hence, we have identified a compound that is capable of impeding cell cycle re-entry by quiescent PTEN(null)/p53(WT) and PTEN(null)/p53(mut) prostate cancer cells likely by promoting c-MYC protein degradation through stabilization of FBXW7. Its usage as a clinical modality to

  14. Deubiquitinating c-Myc: USP36 steps up in the nucleolus.

    Science.gov (United States)

    Sun, Xiao-Xin; Sears, Rosalie C; Dai, Mu-Shui

    2015-01-01

    Ubiquitination plays a key and complex role in the regulation of c-Myc stability, transactivation, and oncogenic activity. c-Myc is ubiquitinated by a number of ubiquitin ligases (E3s), such as SCF(Fbw7) and SCF(Skp2). Depending on the E3s, ubiquitination can either positively or negatively regulate c-Myc levels and activity. Meanwhile, c-Myc ubiquitination can be reversed by deubiquitination. An early study showed that USP28 deubiquitinates c-Myc via interacting with Fbw7α whereas a recent study reveals that USP37 deubiquitinates c-Myc independently of Fbw7 and c-Myc phosphorylation. Consequently, both USP28 and USP37 stabilize c-Myc and enhance its activity. We recently found the nucleolar USP36 as a novel c-Myc deubiquitinase that controls the end-point of c-Myc degradation pathway in the nucleolus. Here we briefly review the current understanding of ubiquitination and deubiquitination regulation of c-Myc and further discuss the USP36-c-Myc regulatory pathway.

  15. cMyc/miR-125b-5p signalling determines sensitivity to bortezomib in preclinical model of cutaneous T-cell lymphomas

    DEFF Research Database (Denmark)

    Manfè, Valentina; Biskup, Edyta; Willumsgaard, Ayalah;

    2013-01-01

    improve their clinical efficacy. Using cutaneous T-cell lymphoma (CTCL) as a model of the chemotherapy-resistant peripheral lymphoid malignancy, we demonstrated that resistance to proteasome inhibition involved a signaling between the oncogene cMyc and miR-125b-5p. Bortezomib repressed cMyc...... and simultaneously induced miR-125b-5p that exerted a cytoprotective effect through the downmodulation of MAD4. Overexpression of cMyc repressed miR-125b-5p transcription and sensitized lymphoma cells to bortezomib. The central role of miR-125b-5p was further confirmed in a mouse model of T-cell lymphoma, where...

  16. Expression of telomerase hTERT in human non-small cell lung cancer and its correlation with c-myc gene

    Institute of Scientific and Technical Information of China (English)

    耿志华; 张敦华; 刘银坤

    2003-01-01

    Objective To investigate the expression of human telomerase catalytic subunit, hTERT, in human non-small cell lung cancer (NSCLC) and its correlations to c-myc gene.Methods hTERT and c-myc mRNA expressions were detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Statistical correlation analysis was made to estimate whether there was interrelation between them.Results Positive rate of hTERT expression in 51 surgically resected lung cancer specimens was 86.3%, significantly higher than that in adjacent non-neoplastic lung tissues and benign lesions, which were 14.3% and 27.3% respectively. No statistical significance was observed between the frequency of hTERT expression and histologic types, degree of differentiation, TNM stages, tumor size or lymph nodes metastases. Correlation analysis revealed that the expression of c-myc gene was significantly related to that of hTERT (correlation coefficient, r=0.633, P<0.001).Conclusions hTERT may be a useful tumor marker in diagnosing lung cancer. Significant correlation between the expression of hTERT and c-myc mRNA indicates that the activation and up-regulation of hTERT might be conferred by over-expression of c-myc gene.

  17. Rabring7 Degrades c-Myc through Complex Formation with MM-1

    Science.gov (United States)

    Torii, Ayako; Tashiro, Erika; Miyazawa, Makoto; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M. M.

    2012-01-01

    We have reported that a novel c-Myc-binding protein, MM-1, repressed E-box-dependent transcription and transforming activities of c-Myc and that a mutation of A157R in MM-1, which is often observed in patients with leukemia or lymphoma, abrogated all of the repressive activities of MM-1 toward c-Myc, indicating that MM-1 is a novel tumor suppressor. MM-1 also binds to the ubiquitin-proteasome system, leading to degradation of c-Myc. In this study, we identified Rabring7, a Rab7-binding and RING finger-containing protein, as an MM-1-binding protein, and we found that Rabring7 mono-ubiquitinated MM-1 in the cytoplasm without degradation of MM-1. Rabring7 was also found to bind to c-Myc and to ubiquitinate c-Myc in a threonine 58-dependent manner. When c-Myc was co-transfected with MM-1 and Rabring7, c-Myc was degraded. Furthermore, it was found that c-Myc was stabilized in MM-1-knockdown cells even when Rabring7 was transfected and that Rabring7 was bound to and co-localized with MM-1 and c-Myc after MM-1 and Rabring7 had been translocated from the cytoplasm to the nucleus. These results suggest that Rabring7 stimulates c-Myc degradation via mono-ubiquitination of MM-1. PMID:22844532

  18. Rabring7 degrades c-Myc through complex formation with MM-1.

    Directory of Open Access Journals (Sweden)

    Rina Narita

    Full Text Available We have reported that a novel c-Myc-binding protein, MM-1, repressed E-box-dependent transcription and transforming activities of c-Myc and that a mutation of A157R in MM-1, which is often observed in patients with leukemia or lymphoma, abrogated all of the repressive activities of MM-1 toward c-Myc, indicating that MM-1 is a novel tumor suppressor. MM-1 also binds to the ubiquitin-proteasome system, leading to degradation of c-Myc. In this study, we identified Rabring7, a Rab7-binding and RING finger-containing protein, as an MM-1-binding protein, and we found that Rabring7 mono-ubiquitinated MM-1 in the cytoplasm without degradation of MM-1. Rabring7 was also found to bind to c-Myc and to ubiquitinate c-Myc in a threonine 58-dependent manner. When c-Myc was co-transfected with MM-1 and Rabring7, c-Myc was degraded. Furthermore, it was found that c-Myc was stabilized in MM-1-knockdown cells even when Rabring7 was transfected and that Rabring7 was bound to and co-localized with MM-1 and c-Myc after MM-1 and Rabring7 had been translocated from the cytoplasm to the nucleus. These results suggest that Rabring7 stimulates c-Myc degradation via mono-ubiquitination of MM-1.

  19. Expression of p53 and C-myc genes and its clinical relevance in the hepatocellular carcinomatous and pericarcinomatous tissues

    Institute of Scientific and Technical Information of China (English)

    Zhao-Shan Niu; Bo-Kian Li; Mei Wang

    2002-01-01

    AIM: To investigate the possible roles of p53 and C-mycgenes in the primary hepatocellular carcinogenesis and therelationship between the liver hyperplastic nodule(LHN) andhepatocellular carcinoma(HCC).METHODS: The expression of p53 and C-myc genes wasdetected immunohist-ochemically in 73 and 60 cases of HCCand pericarcinomatous tissues, respectively .RESULTS: The positive expression of p53 in HCC wassignificantly higher than that in pericarcinomatous tissues(P<0.05). In pericarcinomatous tissues, the p53 expressionwas observed only in LHN, but not in liver cirrhosis (LC) andnormal liver tissues. The positive expression rate of C-mycin HCC or LHN was significantly higher than that in LC ornormal liver tissues (P<0.05 and P<0.01), however, nosignificant difference was found between HCC and LHN(P>0.05). The positive expression rate of p53 and C-myc inHCC was correlated with the histological differentiation, thatin the poorly differentiated was significantly higher than thatin well differentiated samples (P<0.05).CONCLUSION: The overexpression of p53 and C-myc genesmight play a role in the carcinogenesis of HCC; And LHNseems a preneoplastic lesion related to hepatocarcinogenesis;No evidence supports that LC contribute directly to thehepatocarcinogenesis.

  20. Acinar-to-ductal metaplasia accompanies c-myc-induced exocrine pancreatic cancer progression in transgenic rodents.

    Science.gov (United States)

    Grippo, Paul J; Sandgren, Eric P

    2012-09-01

    Several important characteristics of exocrine pancreatic tumor pathogenesis remain incompletely defined, including identification of the cell of origin. Most human pancreatic neoplasms are ductal adenocarcinomas. However, acinar cells have been proposed as the source of some ductal neoplasms through a process of acinar-to-ductal metaplasia. The oncogenic transcription factor c-myc is associated with human pancreatic neoplasms. Transgenic mice overexpressing c-myc under control of acinar cell-specific elastase (Ela) gene regulatory elements not only develop acinar cell carcinomas but also mixed neoplasms that display both acinar-like neoplastic cells and duct-like neoplastic cells. In this report, we demonstrate that, first, c-myc is sufficient to induce acinar hyperplasia, though neoplastic lesions develop focally. Second, cell proliferation remains elevated in the neoplastic duct cell compartment of mixed neoplasms. Third, the proliferation/apoptosis ratio in cells from all lesion types remains constant, suggesting that differential regulation of these processes is not a feature of cancer progression in this model. Fourth, before the development of mixed neoplasms, there is transcriptional activation of the duct cell-specific cytokeratin-19 gene promoter in multicellular foci of amylase-positive acinar neoplasms. This observation provides direct evidence for metaplasia as the mechanism underlying development of ductal neoplastic cells within the context of an acinar neoplasm and suggests that the stimulus for this transformation acts over a multicellular domain or field within a neoplasm. Finally, focal ductal elements develop in some acinar cell carcinomas in Ela-c-myc transgenic rats, indicating that myc-associated acinar-to-ductal metaplasia is not restricted to the mouse.

  1. Resistance to arginine deiminase treatment in melanoma cells is associated with induced argininosuccinate synthetase expression involving c-Myc/HIF-1alpha/Sp4.

    Science.gov (United States)

    Tsai, Wen-Bin; Aiba, Isamu; Lee, Soo-yong; Feun, Lynn; Savaraj, Niramol; Kuo, Macus Tien

    2009-12-01

    Arginine deiminase (ADI)-based arginine depletion is a novel strategy under clinical trials for the treatment of malignant melanoma with promising results. The sensitivity of melanoma to ADI treatment is based on its auxotrophy for arginine due to a lack of argininosuccinate synthetase (AS) expression, the rate-limiting enzyme for the de novo biosynthesis of arginine. We show here that AS expression can be transcriptionally induced by ADI in melanoma cell lines A2058 and SK-MEL-2 but not in A375 cells, and this inducibility was correlated with resistance to ADI treatment. The proximal region of the AS promoter contains an E-box that is recognized by c-Myc and HIF-1alpha and a GC-box by Sp4. Through ChIP assays, we showed that under noninduced conditions, the E-box was bound by HIF-1alpha in all the three melanoma cell lines. Under arginine depletion conditions, HIF-1alpha was replaced by c-Myc in A2058 and SK-MEL-2 cells but not in A375 cells. Sp4 was constitutively bound to the GC-box regardless of arginine availability in all three cell lines. Overexpressing c-Myc by transfection upregulated AS expression in A2058 and SK-MEL-2 cells, whereas cotransfection with HIF-1alpha suppressed c-Myc-induced AS expression. These results suggest that regulation of AS expression involves interplay among positive transcriptional regulators c-Myc and Sp4, and negative regulator HIF-1alpha that confers resistance to ADI treatment in A2058 and SK-MEL-2 cells. Inability of AS induction in A375 cells under arginine depletion conditions was correlated by the failure of c-Myc to interact with the AS promoter.

  2. The Essential Cofactor TRRAP Recruits the Histone Acetyltransferase hGCN5 to c-Myc

    Science.gov (United States)

    McMahon, Steven B.; Wood, Marcelo A.; Cole, Michael D.

    2000-01-01

    The c-Myc protein functions as a transcription factor to facilitate oncogenic transformation; however, the biochemical and genetic pathways leading to transformation remain undefined. We demonstrate here that the recently described c-Myc cofactor TRRAP recruits histone acetylase activity, which is catalyzed by the human GCN5 protein. Since c-Myc function is inhibited by recruitment of histone deacetylase activity through Mad family proteins, these opposing biochemical activities are likely to be responsible for the antagonistic biological effects of c-Myc and Mad on target genes and ultimately on cellular transformation. PMID:10611234

  3. c-myc down-regulation induces apoptosis in human cancer cell lines exposed to RPR-115135 (C31H29NO4), a non-peptidomimetic farnesyltransferase inhibitor.

    Science.gov (United States)

    Russo, Patrizia; Arzani, Dario; Trombino, Sonya; Falugi, Carla

    2003-01-01

    A therapeutic strategy that relies on the use of c-myc antisense in combination with a farnesyltransferase inhibitor, RPR-115135 (C31H29NO4), was studied in human cancer cell lines carrying different mutations (Ras, p53, myc amplification). Cell proliferation was strongly inhibited by the combination and was observed when c-myc oligo (at a concentration that down-regulates c-myc expression) was followed by RPR-115135. Cell cycle analysis demonstrated an accumulation in G0-G1 phase and a tendency to apoptosis (not detectable in cells treated with a single agent). Morphological examination and DNA fragmentation assays (filter binding and enzyme-linked immunosorbent assay DNA fragmentation) confirmed the induction of apoptosis. Apoptosis was not p53- and/or p21(waf-1)-dependent, and the key effector was caspase activation. The combination induced Bax expression and Bcl-2 inhibition. Down-regulation of c-myc amplification carried out a specific role exclusively when Ras was mutated. Exposure of human proliferating lymphocytes to combination did not result in cytotoxicity, suggesting that mechanisms regulating c-myc gene expression during normal T cell proliferation might not be involved. Because of the high percentage of human tumors overexpressing c-myc mRNA and/or protein and, simultaneously, harboring oncogenic Ras mutants (i.e., colon cancers), interrupting the myc- and Ras-signaling pathway would be one of the major focuses on therapy of these types of tumors.

  4. Sodium arsenite alters cell cycle and MTHFR, MT1/2, and c-Myc protein levels in MCF-7 cells.

    Science.gov (United States)

    Ruiz-Ramos, Ruben; López-Carrillo, Lizbeth; Albores, Arnulfo; Hernández-Ramírez, Raúl U; Cebrian, Mariano E

    2009-12-15

    There is limited available information on the effects of arsenic on enzymes participating in the folate cycle. Therefore, our aim was to evaluate the effects of sodium arsenite on the protein levels of methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) and its further relationship with the expression MT1/2 and c-myc in MCF-7 cells. Arsenite treatment (0-10 microM) for 4 h decreased MTHFR levels in a concentration-dependent fashion without significant effects on DHFR. The effects on MTHFR were observed at arsenite concentrations not significantly affecting cell viability. We also observed an increase in S-phase recruitment at all concentrations probed. Lower concentrations ( or =5 microM) or longer treatment periods induced apoptosis. Arsenite also induced dose-dependent increases in MT1/2 and c-Myc protein levels. The levels of MTHFR were inversely correlated to MT1/2 and c-Myc overexpression and increased S-phase recruitment. Our findings indicate that breast epithelial cells are responsive to arsenite and suggest that exposure may pose a risk for breast cancer. The reductions in MTHFR protein levels contribute to understand the mechanisms underlying the induction of genes influencing growth regulation, such as c-myc and MT1/2. However, further research is needed to ascertain if the effects here reported following short-time and high-dose exposure are relevant for human populations chronically exposed to low arsenic concentrations.

  5. Acetylation of the c-MYC oncoprotein is required for cooperation with the HTLV-1 p30{sup II} accessory protein and the induction of oncogenic cellular transformation by p30{sup II}/c-MYC

    Energy Technology Data Exchange (ETDEWEB)

    Romeo, Megan M.; Ko, Bookyung; Kim, Janice; Brady, Rebecca; Heatley, Hayley C.; He, Jeffrey; Harrod, Carolyn K.; Barnett, Braden [Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275-0376 (United States); Ratner, Lee [Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Lairmore, Michael D. [University of California-Davis, School of Veterinary Medicine, One Shields Avenue, Davis, CA 95618 (United States); Martinez, Ernest [Department of Biochemistry, University of California, Riverside, CA 92521 (United States); Lüscher, Bernhard [Institute of Biochemistry, Klinikum, RWTH Aachen University, Pauwelsstrasse 30, 52057 Aachen (Germany); Robson, Craig N. [Northern Institute for Cancer Research, Newcastle University, The Medical School, Newcastle upon Tyne, NE2 4HH (United Kingdom); Henriksson, Marie [Department of Microbiology, Cell and Tumor Biology, Karolinska Institutet, Stockholm (Sweden); Harrod, Robert, E-mail: rharrod@smu.edu [Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275-0376 (United States)

    2015-02-15

    The human T-cell leukemia retrovirus type-1 (HTLV-1) p30{sup II} protein is a multifunctional latency-maintenance factor that negatively regulates viral gene expression and deregulates host signaling pathways involved in aberrant T-cell growth and proliferation. We have previously demonstrated that p30{sup II} interacts with the c-MYC oncoprotein and enhances c-MYC-dependent transcriptional and oncogenic functions. However, the molecular and biochemical events that mediate the cooperation between p30{sup II} and c-MYC remain to be completely understood. Herein we demonstrate that p30{sup II} induces lysine-acetylation of the c-MYC oncoprotein. Acetylation-defective c-MYC Lys→Arg substitution mutants are impaired for oncogenic transformation with p30{sup II} in c-myc{sup −/−} HO15.19 fibroblasts. Using dual-chromatin-immunoprecipitations (dual-ChIPs), we further demonstrate that p30{sup II} is present in c-MYC-containing nucleoprotein complexes in HTLV-1-transformed HuT-102 T-lymphocytes. Moreover, p30{sup II} inhibits apoptosis in proliferating cells expressing c-MYC under conditions of genotoxic stress. These findings suggest that c-MYC-acetylation is required for the cooperation between p30{sup II}/c-MYC which could promote proviral replication and contribute to HTLV-1-induced carcinogenesis. - Highlights: • Acetylation of c-MYC is required for oncogenic transformation by HTLV-1 p30{sup II}/c-MYC. • Acetylation-defective c-MYC mutants are impaired for foci-formation by p30{sup II}/c-MYC. • The HTLV-1 p30{sup II} protein induces lysine-acetylation of c-MYC. • p30{sup II} is present in c-MYC nucleoprotein complexes in HTLV-1-transformed T-cells. • HTLV-1 p30{sup II} inhibits apoptosis in c-MYC-expressing proliferating cells.

  6. Effect of C-myc Antisense Oligodeoxynucleotides on Hypoxia-induced Proliferation of Pulmonary Vascular Pericytes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To study the effect of c-myc antisense oligodeoxynucleotides (ODNs) on proliferation of pulmonary vascular pericytes (PC) induced by hypoxia, cell culture, dot hybridization using probe of digoxigenin-11-dUTP-labeled cDNA,3H-thymidine incorporation, immunocytochemical technique and image analysis methods were used to observe the effect of c-myc antisense ODNs on expression of c-myc gene and proliferating cell nuclear antigen (PCNA), and 3H-thymidine incorporation of PC induced by hypoxia. The results showed that hypoxia could significantly enhance the expression of c-myc and PCNA (P<0.01), and elevate 3H-thymidine incorporation of PC (P<0.01), but antisense ODNs could significantly inhibit the expression of c-myc and PCNA (P<0.05), and 3H-thymidine incorporation of PC (P<0.01). It was suggested that hypoxia could promote the proliferation of PC by up-regulating the expression of c-myc gene, but c-myc antisense ODNs could inhibit hypoxia-induced proliferation of PC by downregulating the expression of c-myc gene.

  7. Deregulation of c-myc and SV40Tag causing brain tumor in mice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Deregulated expressions of both c-myc and simian virus 40 large T antigen (SV40Tag) are consistent features of lots of tumors. To investigate whether the expression of c-myc and SV40Tag in mouse might help develop a model of human tumor, we generated c-myc transgenics by inserting human c-myc gene into pTRE2 of Tet-On system. We obtained conditional expression of SV40Tag transgenics by the Tet-On system from Yangzhou University. Crossing the c-myc transgenic mouse with the SV40Tag transgenic mice to generate bitransgenics we got double-transgenic mice expressing c-myc and SV40Tag by the Tet-On system. After being treated with doxycycline continuously, single-transgenic SV40Tag mice developed brain tumor infrequently (3 of 84, 3.6%) with a long onset (185 d on average). In contrast, double-transgenic c-myc/SV40Tag mice developed brain tumor with a short onset (96 days on average) and a 41% brain tumor incidence rate (7 of 17, 41%). This tumor was assumed to be medulloblastoma. Our experiments suggest that deregulated expression of c-myc and SV40Tag in brain might generate a mouse model of human brain tumor that recapitulates some features of human medulloblastoma.

  8. Effect of Qi-protecting powder (Huqi San) on expression of c-jun, c-fos and c-myc in diethylnitrosamine-mediated hepatocarcinogenesis

    Institute of Scientific and Technical Information of China (English)

    Xia Li; Zheng-Ming Shi; Ping Feng; Zhao-Yang Wen; Xue-Jiang Wang

    2007-01-01

    AIM: To study the inhibitory effect of Huqi San (Qiprotecting powder) on rat prehepatocarcinoma induced by diethylinitrosamine (DEN) by analyzing the mutational activation of c-fos proto-oncogene and over-expression of c-jun and c-myc oncogenes.METHODS: A Solt-Farber two-step test model of prehepatocarcinoma was induced in rats by DEN and 2-acetylaminofluorene (AAF) to investigate the modifying effects of Huqi San on the expression of c-jun, c-fos and c-myc in DEN-mediated hepatocarcinogenesis. Huqi San was made of eight medicinal herbs containing glycoprival granules, in which each milliliter contains 0.38 g crude drugs. γ-glutamy-transpeptidase-isoenzyme (γ-GTase)was determined with histochemical methods. Level of 8-hydroxydeoxyguanosine (OHdG) formed in liver and c-jun, c-fos and c-myc proto-oncogenes were detected by immunohistochemical methods.RESULTS: The level of 8-OHdG, a mark of oxidative DNA damage, was significantly decreased in the liver of rats with prehepatocarcinoma induced by DEN who received 8 g/kg body weight or 4 g/kg body weight Huqi San before (1 wk) and after DEN exposure (4 wk). Huqi Santreated rats showed a significant decrease in number of γ-GT positive foci (P < 0.001, prevention group: 4.96 ±0.72 vs 29.46 ± 2.17; large dose therapeutic group: 7.53± 0.88 vs 29.46 ± 2.17). On the other hand, significant changes in expression of c-jun, c-fos and c-myc were found in Huqi San-treated rats.CONCLUSION: Activation of c-jun, c-fos and c-myc plays a crucial role in the pathogenesis of liver cancer.Huqi San can inhibit the over-expression of c-jun, c-fos and c-myc oncogenes and liver preneolastic lesionsinduced by DEN.

  9. c-Myc is essential to prevent endothelial pro-inflammatory senescent phenotype.

    Directory of Open Access Journals (Sweden)

    Victoria Florea

    Full Text Available The proto-oncogene c-Myc is vital for vascular development and promotes tumor angiogenesis, but the mechanisms by which it controls blood vessel growth remain unclear. In the present work we investigated the effects of c-Myc knockdown in endothelial cell functions essential for angiogenesis to define its role in the vasculature. We provide the first evidence that reduction in c-Myc expression in endothelial cells leads to a pro-inflammatory senescent phenotype, features typically observed during vascular aging and pathologies associated with endothelial dysfunction. c-Myc knockdown in human umbilical vein endothelial cells using lentivirus expressing specific anti-c-Myc shRNA reduced proliferation and tube formation. These functional defects were associated with morphological changes, increase in senescence-associated-β-galactosidase activity, upregulation of cell cycle inhibitors and accumulation of c-Myc-deficient cells in G1-phase, indicating that c-Myc knockdown in endothelial cells induces senescence. Gene expression analysis of c-Myc-deficient endothelial cells showed that senescent phenotype was accompanied by significant upregulation of growth factors, adhesion molecules, extracellular-matrix components and remodeling proteins, and a cluster of pro-inflammatory mediators, which include Angptl4, Cxcl12, Mdk, Tgfb2 and Tnfsf15. At the peak of expression of these cytokines, transcription factors known to be involved in growth control (E2f1, Id1 and Myb were downregulated, while those involved in inflammatory responses (RelB, Stat1, Stat2 and Stat4 were upregulated. Our results demonstrate a novel role for c-Myc in the prevention of vascular pro-inflammatory phenotype, supporting an important physiological function as a central regulator of inflammation and endothelial dysfunction.

  10. c-Myc Alteration Determines the Therapeutic Response to FGFR Inhibitors.

    Science.gov (United States)

    Liu, Hongyan; Ai, Jing; Shen, Aijun; Chen, Yi; Wang, Xinyi; Peng, Xia; Chen, Hui; Shen, Yanyan; Huang, Min; Ding, Jian; Geng, Meiyu

    2017-02-15

    Purpose: Lately, emerging evidence has suggested that oncogenic kinases are associated with specific downstream effectors to govern tumor growth, suggesting potential translational values in kinase-targeted cancer therapy. Tyrosine kinase FGFR, which is aberrant in various cancer types, is one of the most investigated kinases in molecularly targeted cancer therapy. Herein, we investigated whether there exists key downstream effector(s) that converges FGFR signaling and determines the therapeutic response of FGFR-targeted therapy.Experimental Design: A range of assays was used to assess the role of c-Myc in FGFR aberrant cancers and its translational relevance in FGFR-targeted therapy, including assessment of drug sensitivity using cell viability assay, signaling transduction profiling using immunoblotting, and in vivo antitumor efficacy using cancer cell line-based xenografts and patient-derived xenografts models.Results: We discovered that c-Myc functioned as the key downstream effector that preceded FGFR-MEK/ERK signaling in FGFR aberrant cancer. Disruption of c-Myc overrode the cell proliferation driven by constitutively active FGFR. FGFR inhibition in FGFR-addicted cancer facilitated c-Myc degradation via phosphorylating c-Myc at threonine 58. Ectopic expression of undegradable c-Myc mutant conferred resistance to FGFR inhibition both in vitro and in vivo c-Myc level alteration stringently determined the response to FGFR inhibitors, as demonstrated in FGFR-responsive cancer subset, as well as cancers bearing acquired or de novo resistance to FGFR inhibition.Conclusions: This study reveals a stringent association between FGFR and the downstream effector c-Myc in FGFR-dependent cancers, and suggests the potential therapeutic value of c-Myc in FGFR-targeted cancer therapy. Clin Cancer Res; 23(4); 974-84. ©2016 AACR.

  11. Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells.

    Science.gov (United States)

    Wang, Zhaojing; Xu, Yonghong; Meng, Xiangning; Watari, Fumio; Liu, Hudan; Chen, Xiao

    2015-01-01

    Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, β-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

  12. cMyc/miR-125b-5p signalling determines sensitivity to bortezomib in preclinical model of cutaneous T-cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Valentina Manfè

    Full Text Available Successful/effective cancer therapy in low grade lymphoma is often hampered by cell resistance to anti-neoplastic agents. The crucial mechanisms responsible for this phenomenon are poorly understood. Overcoming resistance of tumor cells to anticancer agents, such as proteasome inhibitors, could improve their clinical efficacy. Using cutaneous T-cell lymphoma (CTCL as a model of the chemotherapy-resistant peripheral lymphoid malignancy, we demonstrated that resistance to proteasome inhibition involved a signaling between the oncogene cMyc and miR-125b-5p. Bortezomib repressed cMyc and simultaneously induced miR-125b-5p that exerted a cytoprotective effect through the downmodulation of MAD4. Overexpression of cMyc repressed miR-125b-5p transcription and sensitized lymphoma cells to bortezomib. The central role of miR-125b-5p was further confirmed in a mouse model of T-cell lymphoma, where xenotransplantation of human CTCL cells overexpressing miR-125b-5p resulted in enhanced tumor growth and a shorter median survival. Our findings describe a novel mechanism through which miR-125b-5p not only regulates tumor growth in vivo, but also increases cellular resistance to proteasome inhibitors via modulation of MAD4.

  13. Nuclear localization of phosphorylated c-Myc protein in human tumor cells.

    Directory of Open Access Journals (Sweden)

    C. Soldani

    2010-05-01

    Full Text Available Using immunocytochemical techniques at light and electron microscopy, we analysed the distribution of phosphorylated c-Myc in actively proliferating human HeLa cells. The distribution pattern of c-Myc was also compared with those of other ribonucleoprotein (RNP-containing components (PANA, hnRNP-core proteins, fibrillarin or RNP-associated nuclear proteins (SC-35 splicing factor. Our results provide the first evidence that phosphorylated c-Myc accumulates in the nucleus of tumor cells, where it colocalizes with fibrillarin, both in the nucleolus and in extranucleolar structures.

  14. The long non-coding RNA PARROT is an upstream regulator of c-Myc and affects proliferation and translation

    Science.gov (United States)

    Vučićević, Dubravka; Gehre, Maja; Dhamija, Sonam; Friis-Hansen, Lennart; Meierhofer, David; Sauer, Sascha; Ørom, Ulf Andersson

    2016-01-01

    Long non-coding RNAs are important regulators of gene expression and signaling pathways. The expression of long ncRNAs is dysregulated in cancer and other diseases. The identification and characterization of long ncRNAs is often challenging due to their low expression level and localization to chromatin. Here, we identify a functional long ncRNA, PARROT (Proliferation Associated RNA and Regulator Of Translation) transcribed by RNA polymerase II and expressed at a relatively high level in a number of cell lines. The PARROT long ncRNA is associated with proliferation in both transformed and normal cell lines. We characterize the long ncRNA PARROT as an upstream regulator of c-Myc affecting cellular proliferation and translation using RNA sequencing and mass spectrometry following depletion of the long ncRNA. PARROT is repressed during senescence of human mammary epithelial cells and overexpressed in some cancers, suggesting an important association with proliferation through regulation of c-Myc. With this study, we add to the knowledge of cytoplasmic functional long ncRNAs and extent the long ncRNA-Myc regulatory network in transformed and normal cells. PMID:27129154

  15. Gene expression profiles in primary pancreatic tumors and metastatic lesions of Ela-c-myc transgenic mice

    Directory of Open Access Journals (Sweden)

    Liao Dezhong J

    2008-01-01

    Full Text Available Abstract Background Pancreatic carcinoma usually is a fatal disease with no cure, mainly due to its invasion and metastasis prior to diagnosis. We analyzed the gene expression profiles of paired primary pancreatic tumors and metastatic lesions from Ela-c-myc transgenic mice in order to identify genes that may be involved in the pancreatic cancer progression. Differentially expressed selected genes were verified by semi-quantitative and quantitative RT-PCR. To further evaluate the relevance of some of the selected differentially expressed genes, we investigated their expression pattern in human pancreatic cancer cell lines with high and low metastatic potentials. Results Data indicate that genes involved in posttranscriptional regulation were a major functional category of upregulated genes in both primary pancreatic tumors (PT and liver metastatic lesions (LM compared to normal pancreas (NP. In particular, differential expression for splicing factors, RNA binding/pre-mRNA processing factors and spliceosome related genes were observed, indicating that RNA processing and editing related events may play critical roles in pancreatic tumor development and progression. High expression of insulin growth factor binding protein-1 (Igfbp1 and Serine proteinase inhibitor A1 (Serpina1, and low levels or absence of Wt1 gene expression were exclusive to liver metastatic lesion samples. Conclusion We identified Igfbp1, Serpina1 and Wt1 genes that are likely to be clinically useful biomarkers for prognostic or therapeutic purposes in metastatic pancreatic cancer, particularly in pancreatic cancer where c-Myc is overexpressed.

  16. A regulatory loop involving miR-22, Sp1, and c-Myc modulates CD147 expression in breast cancer invasion and metastasis.

    Science.gov (United States)

    Kong, Ling-Min; Liao, Cheng-Gong; Zhang, Yang; Xu, Jing; Li, Yu; Huang, Wan; Zhang, Yi; Bian, Huijie; Chen, Zhi-Nan

    2014-07-15

    Breast cancer is the most common cancer in women for which the metastatic process is still poorly understood. CD147 is upregulated in breast cancer and has been associated with tumor progression, but little is known about its regulatory mechanisms. In this study, we demonstrated that CD147 was overexpressed in breast cancer tissues and cell lines, and the high expression correlated with tumor invasion and metastasis. We also found that the transcription factors Sp1 and c-Myc could bind to the CD147 promoter and enhance its expression. The CD147 mRNA has a 748-bp 3'-untranslated region (UTR) with many miRNA target sites, suggesting possible regulation by miRNAs. We discovered that miR-22 repressed CD147 expression by directly targeting the CD147 3'UTR. We also determined that miR-22 could indirectly participate in CD147 modulation by downregulating Sp1 expression. miR-22 could form an autoregulatory loop with Sp1, which repressed miR-22 transcription by binding to the miR-22 promoter. Together with the c-Myc-mediated inhibition of miR-22 expression, our investigation identified a miR-22/Sp1/c-Myc network that regulates CD147 gene transcription. In addition, miR-22 overexpression suppressed breast cancer cell invasion, metastasis, and proliferation by targeting CD147 in vitro and in vivo. Furthermore, we found that miR-22 was significantly downregulated in breast cancer tissues and that its expression was inversely correlated with the tumor-node-metastasis stage and lymphatic metastasis in patients. Our study provides the first evidence that an miR-22/Sp1/c-Myc network regulates CD147 upregulation in breast cancer and that miR-22 represses breast cancer invasive and metastatic capacities.

  17. AP-2α Inhibits c-MYC Induced Oxidative Stress and Apoptosis in HaCaT Human Keratinocytes

    Directory of Open Access Journals (Sweden)

    Lei Yu

    2009-01-01

    AP-2 may have a direct effect on the c-myc gene. Chromatin immunoprecipitation assays demonstrated that AP-2 proteins bound to a cluster of AP-2 binding sites located within a 2 kb upstream regulatory region of c-myc These results suggest that the negative regulation of AP-2 on c-MYC activity was achieved through binding of AP-2 protein to the c-myc gene. The effects of AP-2 on c-MYC induced ROS accumulation and apoptosis in epidermal keratinocytes are likely to play an important role in cell growth, differentiation and carcinogenesis of the skin.

  18. ROCK has a crucial role in regulating prostate tumor growth through interaction with c-Myc.

    Science.gov (United States)

    Zhang, C; Zhang, S; Zhang, Z; He, J; Xu, Y; Liu, S

    2014-12-04

    Rho-associated kinase (ROCK) has an essential role in governing cell morphology and motility, and increased ROCK activity contributes to cancer cell invasion and metastasis. Burgeoning data suggest that ROCK is also involved in the growth regulation of tumor cells. However, thus far, the molecular mechanisms responsible for ROCK-governed tumor cell growth have not been clearly elucidated. Here we showed that inhibition of ROCK kinase activity, either by a selective ROCK inhibitor Y27632 or by specific ROCK small interfering RNA (siRNA) molecules, attenuated not only motility but also the proliferation of PC3 prostate cancer cells in vitro and in vivo. Importantly, mechanistic investigation revealed that ROCK endowed cancer cells with tumorigenic capability, mainly by targeting c-Myc. ROCK could increase the transcriptional activity of c-Myc by promoting c-Myc protein stability, and ROCK inhibition reduced c-Myc-mediated expression of mRNA targets (such as HSPC111) and microRNA targets (such as miR-17-92 cluster). We provided evidence demonstrating that ROCK1 directly interacted with and phosphorylated c-Myc, resulting in stabilization of the protein and activation of its transcriptional activity. Suppression of ROCK-c-Myc downstream molecules, such as c-Myc-regulated miR-17, also impaired tumor cell growth in vitro and in vivo. In addition, c-Myc was shown to exert a positive feedback regulation on ROCK by increasing RhoA mRNA expression. Therefore, inhibition of ROCK and its stimulated signaling might prove to be a promising strategy for restraining tumor progression in prostate cancer.

  19. Lack of Cyclin-Dependent Kinase 4 Inhibits c-myc Tumorigenic Activities in Epithelial Tissues

    OpenAIRE

    Miliani de Marval, Paula L; Macias, Everardo; Rounbehler, Robert; Sicinski, Piotr; Kiyokawa, Hiroaki; Johnson, David G.; Conti, Claudio J; Rodriguez-Puebla, Marcelo L.

    2004-01-01

    The proto-oncogene c-myc encodes a transcription factor that is implicated in the regulation of cellular proliferation, differentiation, and apoptosis and that has also been found to be deregulated in several forms of human and experimental tumors. We have shown that forced expression of c-myc in epithelial tissues of transgenic mice (K5-Myc) resulted in keratinocyte hyperproliferation and the development of spontaneous tumors in the skin and oral cavity. Although a number of genes involved i...

  20. The c-Myc Transactivation Domain Is a Direct Modulator of Apoptotic versus Proliferative Signals

    Science.gov (United States)

    Chang, David W.; Claassen, Gisela F.; Hann, Stephen R.; Cole, Michael D.

    2000-01-01

    We have assayed the oncogenic, proliferative, and apoptotic activities of the frequent mutations that occur in the c-myc gene in Burkitt's lymphomas. Some alleles have a modest (50 to 60%) increase in transforming activity; however, the most frequent Burkitt's lymphoma allele (T58I) had an unexpected substantial decrease in transforming activity (85%). All alleles restored the proliferation function of c-Myc in cells that grow slowly due to a c-myc knockout. There was discordance for some alleles between apoptotic and oncogenic activities, but only the T58A allele had elevated transforming activity with a concomitant reduced apoptotic potential. We discovered a novel missense mutation, MycS71F, that had a very low apoptotic activity compared to wild-type Myc, yet this mutation has never been found in lymphomas, suggesting that there is no strong selection for antiapoptotic c-Myc alleles. MycS71F also induced very low levels of cytochrome c release from mitochondria, suggesting a mechanism of action for this mutation. Phosphopeptide mapping provided a biochemical basis for the dramatically different biological activities of the transformation-defective T58I and transformation-enhanced T58A c-Myc alleles. Furthermore, the antiapoptotic survival factor insulin-like growth factor 1 was found to suppress phosphorylation of T58, suggesting that the c-Myc transactivation domain is a direct target of survival signals. PMID:10825194

  1. Alternative translation of the proto-oncogene c-myc by an internal ribosome entry site.

    Science.gov (United States)

    Nanbru, C; Lafon, I; Audigier, S; Gensac, M C; Vagner, S; Huez, G; Prats, A C

    1997-12-19

    The human proto-oncogene c-myc encodes two proteins, c-Myc1 and c-Myc2, from two initiation codons, CUG and AUG, respectively. It is also transcribed from four alternative promoters (P0, P1, P2, and P3), giving rise to different RNA 5'-leader sequences, the long sizes of which suggest that they must be inefficiently translated by the classical ribosome scanning mechanism. Here we have examined the influence of three c-myc mRNA 5'-leaders on the translation of chimeric myc-CAT mRNAs. We observed that in the reticulocyte rabbit lysate, these 5'-leaders lead to cap-independent translation initiation. To determine whether this kind of initiation resulted from the presence of an internal ribosome entry site (IRES), COS-7 cells were transfected with bicistronic vectors containing the different c-myc 5'-leaders in the intercistronic region. An IRES was identified, requiring elements located within the P2 leader, between nucleotides -363 and -94 upstream from the CUG start codon. This is the first demonstration of the existence of IRES-dependent translation for a proto-oncogene. This IRES could be a translation enhancer, allowing activation of c-myc expression under the control of trans-acting factors and in response to specific cell stimuli.

  2. Regulation of human ornithine decarboxylase expression by the c-Myc.Max protein complex.

    Science.gov (United States)

    Peña, A; Reddy, C D; Wu, S; Hickok, N J; Reddy, E P; Yumet, G; Soprano, D R; Soprano, K J

    1993-12-25

    The presence of a CACGTG element within a region of the human ornithine decarboxylase (ODC) promoter located at -491 to -474 base pairs 5' to the start site of transcription suggested that the c-Myc.Max protein complex may play a role in the regulation of ODC expression during growth. Electrophoretic mobility shift assays and methylation interference analysis showed that the nuclei of WI-38 cells expressing ODC contained proteins that bound to this region of the ODC gene in a manner that correlated with growth-associated ODC expression. Also, use of antibodies against c-Myc and Max and purified recombinant c-Myc and Max protein in the electrophoretic mobility shift assay confirmed that these proteins can specifically bind this portion of the human ODC promoter. Transient transfection studies showed that increase in the level of c-Myc and/or Max led to a significant enhancement of expression of a human ODC promoter-CAT reporter construct. Moreover, treatment of actively growing WI-38 cells with an antisense oligomer to c-Myc reduced the amount of endogenous protein complex formed and the amount of endogenous ODC mRNA expressed. These studies show that the c-Myc.Max protein complex plays a role in the transcriptional regulation of human ODC in vivo.

  3. Transcript Regulation of Human Telomerase Reverse Transcriptase by c-myc and mad1

    Institute of Scientific and Technical Information of China (English)

    Lin ZOU; Peng-Hui ZHANG; Chun-Li LUO; Zhi-Guang TU

    2005-01-01

    Telomerase activity is highly positive correlated to most malignant neoplasms. Human telomerase reverse transcriptase (hTERT) is the rate-limiting factor of telomerase activity. Recent studies have shown that the expression of hTERT is mainly determined by its transcript regulation. Among the transcript regulation factors of hTERT, c-myc and mad1 are well known. Here, we constructed c-myc and mad1 eukaryotic expression vectors, then co-transfected them with the wild-type (Tw) or mutant hTERT promoter (Td)luciferase reporter plasmid, which were double-mutated in the E-box sequences from CACGTG to CACCTG of Tw. The change of luciferase activity in different cells was detected. The results showed that Tw was obviously activated in T24 and EJ bladder cancer cells, but not in normal fibrocytes. c-myc and mad1 had positive and negative effects respectively on the Tw transcript in a dose-dependent manner, while the roles of c-myc and mad1 in regulating the Td transcript were reversed. c-myc combined with mad1 can downregulate Tw but not Td. These observations indicate that c-myc and mad1 can regulate the hTERT transcript in a different manner in hTERT positive cells, but not in normal cells. This may provide an insight into some telomerase-related carcinogenesis mechanisms.

  4. SirT1 knockdown potentiates radiation-induced bystander effect through promoting c-Myc activity and thus facilitating ROS accumulation.

    Science.gov (United States)

    Xie, Yuexia; Tu, Wenzhi; Zhang, Jianghong; He, Mingyuan; Ye, Shuang; Dong, Chen; Shao, Chunlin

    2015-02-01

    Radiation-induced bystander effect (RIBE) has important implications for secondary cancer risk assessment during cancer radiotherapy, but the bystander signaling processes, especially under hypoxic condition, are still largely unclear. The present study found that micronuclei (MN) formation could be induced in the non-irradiated HL-7702 hepatocyte cells after being treated with the conditioned medium from irradiated hepatoma HepG2 and SK-Hep-1 cells under either normoxia or hypoxia. This bystander response was dramatically diminished or enhanced when the SirT1 gene of irradiated hepatoma cells was overexpressed or knocked down, respectively, especially under hypoxia. Meanwhile, SirT1 knockdown promoted transcriptional activity for c-Myc and facilitated ROS accumulation. But both of the increased bystander responses and ROS generation due to SirT1-knockdown were almost completely suppressed by c-Myc interference. Moreover, ROS scavenger effectively abolished the RIBE triggered by irradiated hepatoma cells even with SirT1 depletion. These findings provide new insights that SirT1 has a profound role in regulating RIBE where a c-Myc-dependent release of ROS may be involved.

  5. SirT1 knockdown potentiates radiation-induced bystander effect through promoting c-Myc activity and thus facilitating ROS accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yuexia [Institute of Radiation Medicine, Fudan University, Shanghai (China); Central Laboratory, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai (China); Tu, Wenzhi; Zhang, Jianghong; He, Mingyuan; Ye, Shuang; Dong, Chen [Institute of Radiation Medicine, Fudan University, Shanghai (China); Shao, Chunlin, E-mail: clshao@shmu.edu.cn [Institute of Radiation Medicine, Fudan University, Shanghai (China)

    2015-02-15

    Highlights: • γ-Irradiation induced bystander effects between hepatoma cells and hepatocyte cells. • SirT1 played a protective role in regulating this bystander effect. • SirT1 contributed to the protective effects via elimination the accumulation of ROS. • The activity of c-Myc is critical for maintaining the protective role of SirT1. - Abstract: Radiation-induced bystander effect (RIBE) has important implications for secondary cancer risk assessment during cancer radiotherapy, but the bystander signaling processes, especially under hypoxic condition, are still largely unclear. The present study found that micronuclei (MN) formation could be induced in the non-irradiated HL-7702 hepatocyte cells after being treated with the conditioned medium from irradiated hepatoma HepG2 and SK-Hep-1 cells under either normoxia or hypoxia. This bystander response was dramatically diminished or enhanced when the SirT1 gene of irradiated hepatoma cells was overexpressed or knocked down, respectively, especially under hypoxia. Meanwhile, SirT1 knockdown promoted transcriptional activity for c-Myc and facilitated ROS accumulation. But both of the increased bystander responses and ROS generation due to SirT1-knockdown were almost completely suppressed by c-Myc interference. Moreover, ROS scavenger effectively abolished the RIBE triggered by irradiated hepatoma cells even with SirT1 depletion. These findings provide new insights that SirT1 has a profound role in regulating RIBE where a c-Myc-dependent release of ROS may be involved.

  6. THE EFFECTS OF RETINOIC ACID ON EXPRESSION OF C-MYC, C-FOS IN LEUKEMIC PROMYELOCYTES

    Institute of Scientific and Technical Information of China (English)

    邵国英; 徐荣婷; 孙关林; 欧阳仁荣; 应大明

    1992-01-01

    The expression of c-myc, c-fos of leukemic promyelocytes (HL-60 and acute promyelocytic leukemia cells) from 18 acute promyelocytic leukemia (APL) patients treated with all-trans retinoic acid (RA) in vitro was studied. There was no expression of c-fos in HL-60 cells and APL cells from 17 patients. But in one case, a slight expression of c-fos in leukemic cells was observed, and the alteration of expression level was found during the treatment of the cells with RA in vitro. The expression of c-myc in HL-60 cells induced by RA was altered, decrease in the early, increase in the middle, and decline in the later stage were found. The c-myc expression in leukemic cells of eighteen APL patients was variable. There was c-myc expression in eleven APL cells, but no expression in the others. The APL cells with c-myc expression were treated with RA in vitro to observe the kinetic changes of c-myc RNA level. The results showed that the expression of c-myc was gradually decreased except in few cases. Using in situ hybridization technique for detecting the alteration of c-myc expression in leukemic cells of two APL patients. the high level of c-myc before RA treatment and low level of c-myc expression after obtaining complete remission induced by RA were found. The possibility of different proto-oncogenes implicated differentiation was discussed.

  7. Microcystin-LR stabilizes c-myc protein by inhibiting protein phosphatase 2A in HEK293 cells.

    Science.gov (United States)

    Fan, Huihui; Cai, Yan; Xie, Ping; Xiao, Wuhan; Chen, Jun; Ji, Wei; Zhao, Sujuan

    2014-05-07

    Microcystin-LR is the most toxic and the most frequently encountered toxin produced by the cyanobacteria in the contaminated aquatic environment. Previous studies have demonstrated that Microcystin-LR is a potential carcinogen for animals and humans, and the International Agency for Research on Cancer has classified Microcystin-LR as a possible human carcinogen. However, the precise molecular mechanisms of Microcystin-LR-induced carcinogenesis remain a mystery. C-myc is a proto-oncogene, abnormal expression of which contributes to the tumor development. Although several studies have demonstrated that Microcystin-LR could induce c-myc expression at the transcriptional level, the exact connection between Microcystin-LR toxicity and c-myc response remains unclear. In this study, we showed that the c-myc protein increased in HEK293 cells after exposure to Microcystin-LR. Coexpression of protein phosphatase 2A and two stable c-myc protein point mutants (either c-myc(T58A) or c-myc(S62A)) showed that Microcystin-LR increased c-myc protein level mainly through inhibiting protein phosphatase 2A activity which altered the phosphorylation status of serine 62 on c-myc. In addition, we also showed that Microcystin-LR could increase c-myc promoter activity as revealed by luciferase reporter assay. And the TATA box for P1 promoter of c-myc might be involved. Our results suggested that Microcystin-LR can stimulate c-myc transcription and stabilize c-myc protein, which might contribute to hepatic tumorigenesis in animals and humans.

  8. c-Myc and AMPK Control Cellular Energy Levels by Cooperatively Regulating Mitochondrial Structure and Function.

    Directory of Open Access Journals (Sweden)

    Lia R Edmunds

    Full Text Available The c-Myc (Myc oncoprotein and AMP-activated protein kinase (AMPK regulate glycolysis and oxidative phosphorylation (Oxphos although often for different purposes. Because Myc over-expression depletes ATP with the resultant activation of AMPK, we explored the potential co-dependency of and cross-talk between these proteins by comparing the consequences of acute Myc induction in ampk+/+ (WT and ampk-/- (KO murine embryo fibroblasts (MEFs. KO MEFs showed a higher basal rate of glycolysis than WT MEFs and an appropriate increase in response to activation of a Myc-estrogen receptor (MycER fusion protein. However, KO MEFs had a diminished ability to increase Oxphos, mitochondrial mass and reactive oxygen species in response to MycER activation. Other differences between WT and KO MEFs, either in the basal state or following MycER induction, included abnormalities in electron transport chain function, levels of TCA cycle-related oxidoreductases and cytoplasmic and mitochondrial redox states. Transcriptional profiling of pathways pertinent to glycolysis, Oxphos and mitochondrial structure and function also uncovered significant differences between WT and KO MEFs and their response to MycER activation. Finally, an unbiased mass-spectrometry (MS-based survey capable of quantifying ~40% of all mitochondrial proteins, showed about 15% of them to be AMPK- and/or Myc-dependent in their steady state. Significant differences in the activities of the rate-limiting enzymes pyruvate kinase and pyruvate dehydrogenase, which dictate pyruvate and acetyl coenzyme A abundance, were also differentially responsive to Myc and AMPK and could account for some of the differences in basal metabolite levels that were also detected by MS. Thus, Myc and AMPK are highly co-dependent and appear to engage in significant cross-talk across numerous pathways which support metabolic and ATP-generating functions.

  9. VARIATION AND SIGNIFICANCE OF C-MYC PROTEIN IN RAT CARDIAC VOLUME-OVERLOAD HYP ERTROPHY

    Institute of Scientific and Technical Information of China (English)

    刘华胜; 马爱群; 王一理; 刘勇; 李恒力; 田红燕

    2002-01-01

    Objective To investigate the change of c-myc protein, which was chosen as the response indicator to volume-overload. Methods The time and spatial course of c-myc protein expressi on on the model of rat cardiac volume-overload hyper trophy was examined by immunohistochemical study. Results The immunohistochemica l study indicated the expression of c-myc protein was increased obviously at 4 -6 hours (62.73%) than that of control (45.41%, P<0.01) after the volume-o verload, then decreased gradually along with development of volume-overload hyp ertrophy and was decreased extremely at 5 months(r=-0.514,P<0.01).Conclusion There are disorders in the signal transduction pathways governing the hypertrophic respon se of cardiomyocytes in hypertrophic myocardium. C-myc gene and the product of it may be only the promoter gene of myocardial hypertrophy. Once switching on, c-myc gene and the product of it do not act anymore;While it may be that c-my c gene and the product of it increased following with myocardial hypertrophy, an d have not direct relation to the occurrence and development of myocardial hyper trophy.

  10. The Role of c-Myc and miRNAs on EMT and the TGF-betaSwitch in Primary Intermediate Basal Cells Isolated From Prostate Cancer

    Science.gov (United States)

    2013-03-01

    embryos by retroviral vectors. Proc Natl Acad Sci U S A 86, 2224-2228. For Peer Review c-myc expression and MEK1 induced Erk2...cells using the pBABE-puro retroviral vector (a kind gift from Dr. Christian Sell, Drexel University College of Medicine). MEK1-DD and MEK2-DD were also...retroviral vector (a kind gift from Dr. Christian Sell, Drexel University College of Medicine). MEK1-DD and MEK2-DD were also over-expressed in cells

  11. Targeting c-Myc on cell growth and vascular endothelial growth factor expression in IN500 glioblastoma cells

    Institute of Scientific and Technical Information of China (English)

    HU Yu-hua; KONG Shi-qi; KONG Hai-bo; WU Jian-liang; CHEN Ze

    2012-01-01

    Background The level of c-Myc is closely associated with high pathological grade and the poor prognosis of gliomas.Vascular endothelial growth factor (VEGF) is the most important angiogenic factor that potently stimulates the proliferation and migration of vascular endothelial cells.This study aimed to address the biological importance of c-Myc in the development of gliomas,we downregulated the expression of c-Myc in the human glioblastoma cell line IN500 and studied the in vitro effect on cellular growth,proliferation,and apoptosis and the expression of VEGF and the in vivo effect on tumor formation in a xenograft mouse model.Methods IN500△ cells were stably transfected with shRNA-expressing plasmids for either c-Myc (pCMYC-shRNA) or as a control (pCtrl-shRNA).Following establishment of stable cells,the mRNA expressions of c-Myc and VEGF were examined by reverse transcription (RT)-PCR,and c-Myc and VEGF proteins by Western blotting and immunohistochemistry.Cell-cycle progression and apoptosis were determined by flow cytometry.The in vivo effect of targeting c-Myc was determined by subcutaneous injection of stable cells into immunodeficient nude mice.Results The stable transfection of pCMYC-shRNA successfully knocked down the steady-state mRNA and protein levels of c-Myc in IN500,which positively correlated with the downregulation of VEGF.Downregulating c-Myc in vitro also led to G1-S arrest and enhanced apoptosis.In vivo,targeting c-Myc reduced xenograft tumor formation and resulted in significantly smaller tumors.Conclusions c-Myc has multiple functions in glioblastoma development that include regulating cell-cycle,apoptosis,and VEGF expression.Targeting c-Myc expression may be a promising therapy for malignant glioma.

  12. Increased transcription of the c-myc oncogene in two methylcholanthrene-induced quail fibroblastic cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Saule, S.; Martin, P.; Gegonne, A.; Begue, A.; Lagrou, C.; Stehelin, D.

    1984-12-01

    The expression of three c-onc genes (c-erb, c-myc, c-myb) was investigated in five cell lines established from fibrosarcomas induced with 20-methylcholanthrene (MCA) of Japanese quails. These cell lines showed low levels of the three c-onc genes, with the exception of two cell lines that accumulated moderate (MCAQ 1-4) and large amounts (MCAQ 3-5) of c-myc RNA. Molecular cloning and restriction endonuclease analyses indicated that expression of c-myc in these two cell lines were not associated with detectable rearrangements in the c-myc locus, that the size of the c-myc transcript (2.7 kb) in MCAQ 3-5 was similar to that of the normal c-myc messenger RNAs (mRNA) and that the transcriptional activatin observed in MCAQ 3-5 was not mediated by the LTR (long terminal repeat) of a proximate ALV (avian leukosis virus) provirus. Finally, when analyzed with the restriction enzymes Msp I and Hpa II, the c-myc locus of MCAQ 3-5 and MCAQ 1-4 was found hypomethylated as compared with that of the other cell lines tested that show low levels of c-myc transcripts. Results suggest that one of the ways methylcholanthrene could mediate transformation is by inducing an abnormal regulation of the c-myc gene.

  13. HBXIP and LSD1 Scaffolded by lncRNA Hotair Mediate Transcriptional Activation by c-Myc.

    Science.gov (United States)

    Li, Yinghui; Wang, Zhen; Shi, Hui; Li, Hang; Li, Leilei; Fang, Runping; Cai, Xiaoli; Liu, Bowen; Zhang, Xiaodong; Ye, Lihong

    2016-01-15

    c-Myc is regarded as a transcription factor, but the basis for its function remains unclear. Here, we define a long noncoding RNA (lncRNA)/protein complex that mediates the transcriptional activation by c-Myc in breast cancer cells. Among 388 c-Myc target genes in human MCF-7 breast cancer cells, we found that their promoters could be occupied by the oncoprotein HBXIP. We confirmed that the HBXIP expression correlated with expression of the c-Myc target genes cyclin A, eIF4E, and LDHA. RNAi-mediated silencing of HBXIP abolished c-Myc-mediated upregulation of these target genes. Mechanistically, HBXIP interacted directly with c-Myc through the leucine zippers and recruited the lncRNA Hotair along with the histone demethylase LSD1, for which Hotair serves as a scaffold. Silencing of HBXIP, Hotair, or LSD1 was sufficient to block c-Myc-enhanced cancer cell growth in vitro and in vivo. Taken together, our results support a model in which the HBXIP/Hotair/LSD1 complex serves as a critical effector of c-Myc in activating transcription of its target genes, illuminating long-standing questions on how c-Myc drives carcinogenesis.

  14. Interrelationship between chromosome 8 aneuploidy, C-MYC amplification and increased expression in individuals from northern Brazil with gastric adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Danielle Queiroz Calcagno; Márcia Valéria Pitombeira Ferreira; Marília de Arruda Cardoso Smith; Rommel Rodríguez Burbano; Mariana Ferreira Leal; Aline Damaceno Seabra; André Salim Khayat; Elizabeth Suchi Chen; Samia Demachki; Paulo Pimentel Assump(c)(a)o; Mario Henrique Gir(a)o Faria; Silvia Helena Barem Rabenhorst

    2006-01-01

    AIM: To investigate chromosome 8 numerical aberrations, C-MYC oncogene alterations and its expression in gastric cancer and to correlate these findings with histopathological characteristics of gastric tumors.METHODS: Specimens were collected surgically from seven patients with gastric adenocarcinomas. Immunostaining for C-MYC and dual-color fluorescence in situ hybridization (FISH) for C-MYC gene and chromosome 8centromere were performed.RESULTS: All the cases showed chromosome 8 aneuploidy and C-MYC amplification, in both the diffuse and intestinal histopathological types of Lauren. No significant difference (P < 0.05) was observed between the level of chromosome 8 ploidy and the site, stage or histological type of the adenocarcinomas. C-MYC high amplification,like homogeneously stained regions (HSRs) and double minutes (DMs), was observed only in the intestinal-type.Structural rearrangement of C-MYC, like translocation,was observed only in the diffuse type. Regarding C-MYC gene, a significant difference (P < 0.05) was observed between the two histological types. The C-MYC protein was expressed in all the studied cases. In the intestinaltype the C-MYC immunoreactivity was localized only in the nucleus and in the diffuse type in the nucleus and cytoplasm.CONCLUSION: Distinct patterns of alterations between intestinal and diffuse types of gastric tumors support the hypothesis that these types follow different genetic pathways.

  15. Expression of c-myc during differentiation of the human teratocarcinoma cell line Tera-2.

    Science.gov (United States)

    Schofield, P N; Engstrom, W; Lee, A J; Biddle, C; Graham, C F

    1987-08-01

    The quantity of c-myc mRNA was measured during the retinoic-acid-induced differentiation of the pluripotent human teratoma cell line, Tera-2 cl. 13. As the cells were exposed to retinoic acid for longer periods of time the duration of the cell cycle progressively increased (measured by the rate of S phase entry) until the cells were effectively quiescent and expressed characteristic differentiation markers. Under these circumstances steady-state levels of c-myc expression increased by up to 1.6-fold with respect to rapidly growing undifferentiated cells. Southern blot analysis of the c-myc genes in Tera-2 indicated no major rearrangement or amplification in the cell line.

  16. Investigation of multivalent interactions between conjugate of quantum dots with c-Myc peptide tag and the anti-c-Myc antibody by capillary electrophoresis with fluorescence detection.

    Science.gov (United States)

    Wang, Jianhao; Yang, Li; Liu, Li; Wu, Hao; Wang, Jianpeng; Jiang, Pengju; Jiang, Xiyuan; Qiu, Lin

    2016-12-01

    Herein, we report an assay for detecting the binding of a multivalent peptide and antibody within a capillary with the use of fluorescence coupled capillary electrophoresis. Quantum dots and a c-Myc tag containing peptide EQKLISEEDLG4 H6 were injected sequentially and formed a multivalent quantum dot-EQKLISEEDLG4 H6 assembly within the capillary. The efficiency of the quantum dot-peptide self-assembly was affected by the peptide/quantum dot molar ratio, sampling time, and interval time. Finally, the binding of the monoclonal anti-c-Myc antibody and the multivalent quantum dot-EQKLISEEDLG4 H6 ligand was studied using an in-capillary assay. The microscopic dissociation constant for the self-assembly of monoclonal anti-c-Myc antibody and quantum dot-EQKLISEEDLG4 H6 was determined to be 14.1 μM with a stoichiometry of the peptide-antibody complex of 1.7 determined after fitting this to the Hill equation. This method can be further extended to detect a wide range of biomolecule-biomolecule binding interactions.

  17. cMyc Regulates the Size of the Premigratory Neural Crest Stem Cell Pool.

    Science.gov (United States)

    Kerosuo, Laura; Bronner, Marianne E

    2016-12-06

    The neural crest is a transient embryonic population that originates within the central nervous system (CNS) and then migrates into the periphery and differentiates into multiple cell types. The mechanisms that govern neural crest stem-like characteristics and self-renewal ability are poorly understood. Here, we show that the proto-oncogene cMyc is a critical factor in the chick dorsal neural tube, where it regulates the size of the premigratory neural crest stem cell pool. Loss of cMyc dramatically decreases the number of emigrating neural crest cells due to reduced self-renewal capacity, increased cell death, and shorter duration of the emigration process. Interestingly, rather than via E-Box binding, cMyc acts in the dorsal neural tube by interacting with another transcription factor, Miz1, to promote self-renewal. The finding that cMyc operates in a non-canonical manner in the premigratory neural crest highlights the importance of examining its role at specific time points and in an in vivo context.

  18. Dose-adjusted Chemotherapy for Untreated c-MYC-positive Lymphoma

    Science.gov (United States)

    In this trial, adult patients with newly diagnosed Burkitt lymphoma or c-MYC-positive DLBCL will be separated into low-risk and high-risk groups; those in the low-risk group will be treated with at least three cycles of dose-adjusted EPOCH-R

  19. Transactivation Domain of Human c-Myc Is Essential to Alleviate Poly(Q)-Mediated Neurotoxicity in Drosophila Disease Models.

    Science.gov (United States)

    Raj, Kritika; Sarkar, Surajit

    2017-03-18

    Polyglutamine (poly(Q)) disorders, such as Huntington's disease (HD) and spinocerebellar ataxias, represent a group of neurological disorders which arise due to an atypically expanded poly(Q) tract in the coding region of the affected gene. Pathogenesis of these disorders inside the cells begins with the assembly of these mutant proteins in the form of insoluble inclusion bodies (IBs), which progressively sequester several vital cellular transcription factors and other essential proteins, and finally leads to neuronal dysfunction and apoptosis. We have shown earlier that targeted upregulation of Drosophila myc (dmyc) dominantly suppresses the poly(Q) toxicity in Drosophila. The present study examines the ability of the human c-myc proto-oncogene and also identifies the specific c-Myc isoform which drives the mitigation of poly(Q)-mediated neurotoxicity, so that it could be further substantiated as a potential drug target. We report for the first time that similar to dmyc, tissue-specific induced expression of human c-myc also suppresses poly(Q)-mediated neurotoxicity by an analogous mechanism. Among the three isoforms of c-Myc, the rescue potential was maximally manifested by the full-length c-Myc2 protein, followed by c-Myc1, but not by c-MycS which lacks the transactivation domain. Our study suggests that strategies focussing on the transactivation domain of c-Myc could be a very useful approach to design novel drug molecules against poly(Q) disorders.

  20. Sensitivity of nuclear c-myc levels and induction to differentiation-inducing agents in human colon tumor cell lines.

    Science.gov (United States)

    Taylor, C W; Kim, Y S; Childress-Fields, K E; Yeoman, L C

    1992-02-29

    Six human colon tumor cell lines were analyzed for their constitutive levels of the c-myc protein. The nuclear proto-oncogene, c-myc, was detected as an expressed product in all of the human colon tumor cell lines analyzed. The poorly differentiated cell lines HCT116, RKO and C showed c-myc levels that averaged 2-fold greater than their well-differentiated counterparts, i.e., GEO, CBS and FET. When c-myc levels and responses to serum induction were analyzed in the presence of inducers of differentiation, i.e., dimethylformamide, retinoic acid, sodium butyrate and TGF-beta, distinct patterns of sensitivity and resistance emerged. Nuclear c-myc levels were reduced in all the colon cell phenotypes treated with dimethylformamide or sodium butyrate. Only the well-differentiated human colon tumor cell lines were responsive to transforming growth factor-beta. Only one of the human colon tumor cell lines (GEO) responded to retinoic acid. Increased levels of c-myc protein were found to correlate well with greater growth rates and with poor differentiation class. Similarly, a parallel sensitivity to down-regulation of c-myc levels and attenuation of c-myc induction curves for inducers of differentiation were observed in growth sensitive human colon tumor cell lines.

  1. NFATC1 promotes cell growth and tumorigenesis in ovarian cancer up-regulating c-Myc through ERK1/2/p38 MAPK signal pathway.

    Science.gov (United States)

    Xu, Wenwen; Gu, Junjie; Ren, Qingling; Shi, Yanqiu; Xia, Qinhua; Wang, Jing; Wang, Suli; Wang, Yingchun; Wang, Jinhua

    2016-04-01

    It has been reported that nuclear factor of activated T cells (NFATC1) was up-regulated in cancers mediating malignant behaviors. However, the role of NFATC1 in ovarian cancer has not been elucidated. In the present study, we undertook to explore the clinicopathological significance of NFATC1 expression and the mechanism by which NFATC1 works in ovarian cancer. Expression status of NFATC1 was examined using immunohistochemistry. Both knockdown and re-expression of NFATC1 on ovarian cancer cells were employed to observe the effect overgrowth. It was found that NFATC1 was significantly overexpressed in ovarian cancer tissues in comparison with paired normal control tissues and that overexpression of NFATC1 was significantly associated with metastasis and poor prognosis on clinical tissue level. In in vitro ovarian cancer cell lines, we found that NFATC1 can promote proliferation up-regulating c-myc through activation of ERK1/2/p38/MAPK signal pathway. Together, the results we obtained demonstrated that NFATC1 played oncogenic role in ovarian cancer. Mechanistically, NFATC1 promoted growth of ovarian cancer cells up-regulating c-myc through activation of ERK1/2/p38/MAPK signal pathway, suggesting that NFATC1 might be used as a therapeutic target for ovarian cancer.

  2. Oncogene amplification detected by in situ hybridization in radiation induced rat skin tumors. [C-myc:a3

    Energy Technology Data Exchange (ETDEWEB)

    Yi Jin.

    1991-02-01

    Oncogene activation may play an important role in radiation induced carcinogenesis. C-myc oncogene amplification was detected by in situ hybridization in radiation-induced rat skin tumors, including squamous and basal cell carcinomas. In situ hybridization was performed with a biotinylated human c-myc third exon probe, visualized with an avidin-biotinylated alkaline phosphate detection system. No c-myc oncogene amplification was detected in normal rat skin at very early times after exposure to ionizing radiation, which is consistent with the view that c-myc amplification is more likely to be related to carcinogenesis than to normal cell proliferation. The incorporation of tritiated thymidine into the DNA of rat skin cells showed that the proliferation of epidermal cells reached a peak on the seventh day after exposure to ionizing radiation and then decreased. No connection between the proliferation of epidermal cell and c-myc oncogene amplification in normal or irradiated rat skin was found. The results indicated that c-myc amplification as measured by in situ hybridization was correlated with the Southern bolt results, but only some of the cancer cells were amplified. The c-myc positive cells were distributed randomly within regions of the tumor and exhibited a more uniform nuclear structure in comparison to the more vacuolated c-myc negative cells. No c-myc signal was detected in unirradiated normal skin or in irradiated skin cells near the tumors. C-myc amplification appears to be cell or cell cycle specific within radiation-induced carcinomas. 28 refs., 3 figs., 3 tabs.

  3. Inversed relationship between CD44 variant and c-Myc due to oxidative stress-induced canonical Wnt activation

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Go J., E-mail: medical21go@yahoo.co.jp; Saya, Hideyuki

    2014-01-10

    Highlights: •CD44 variant8–10 and c-Myc are inversely expressed in gastric cancer cells. •Redox-stress enhances c-Myc expression via canonical Wnt signal. •CD44v, but not CD44 standard, suppresses redox stress-induced Wnt activation. •CD44v expression promotes both transcription and proteasome degradation of c-Myc. •Inversed expression pattern between CD44v and c-Myc is often recognized in vivo. -- Abstract: Cancer stem-like cells express high amount of CD44 variant8-10 which protects cancer cells from redox stress. We have demonstrated by immunohistochemical analysis and Western blotting, and reverse-transcription polymerase chain reaction, that CD44 variant8-10 and c-Myc tend to show the inversed expression manner in gastric cancer cells. That is attributable to the oxidative stress-induced canonical Wnt activation, and furthermore, the up-regulation of the downstream molecules, one of which is oncogenic c-Myc, is not easily to occur in CD44 variant-positive cancer cells. We have also found out that CD44v8-10 expression is associated with the turn-over of the c-Myc with the experiments using gastric cancer cell lines. This cannot be simply explained by the model of oxidative stress-induced Wnt activation. CD44v8-10-positive cancer cells are enriched at the invasive front. Tumor tissue at the invasive area is considered to be composed of heterogeneous cellular population; dormant cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup high}/ c-Myc {sup low} and proliferative cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup low}/ c-Myc {sup high}.

  4. Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaojing [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China); Xu, Yonghong [Institute of Ophthalmological Research, Department of Ophthalmology, Renmin Hospital of Wuhan University, 430060 Wuhan (China); Meng, Xiangning [School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Watari, Fumio [Department of Biomedical, Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Liu, Hudan, E-mail: hudanliu@hust.edu.cn [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China); Chen, Xiao, E-mail: mornsmile@yahoo.com [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China)

    2015-01-01

    Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, β-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

  5. The c-myc coding DNA sequences of cyprinids (Teleostei: Cypriniformes): Implications for phylogeny

    Institute of Scientific and Technical Information of China (English)

    KONG XiangHui; WANG XuZhen; GAN XiaoNi; HE ShunPing

    2007-01-01

    The family Cyprinidae is one of the largest fish families in the world, which is widely distributed in East Asian, with obvious difference in characteristic size among species. The phylogenetic analysis of cyprinid taxa based on the functionally important genes can help to understand the speciation and functional divergence of the Cyprinidae. The c-myc gene is an important gene regulating individual growth.In the present study, the sequence variations of the cyprinid c-myc gene and their phylogenetic significance were analyzed. The 41 complete sequences of the c-myc gene were obtained from cyprinids and outgroups through PCR amplification and clone. The coding DNA sequences of the c-myc gene were used to infer molecular phylogenetic relationships within the Cyprinidae. Myxocyprinus asiaticus (Catostomidae), Misgurnus anguillicaudatus (Cobitidae) and Hemimyzon sinensis (Homalopteridae)were assigned to the outgroup taxa. Phylogenetic analyses using maximum parsimony (MP), maximum likelihood (ML), and Bayesian retrieved similar topology. Within the Cyprinidae, Leuciscini and Barbini formed the monophyletic lineage respectively with high nodal supports. Leuciscini comprises Xenocyprinae, Cultrinae, East Asian species of Leuciscinae and Danioninae, Gobioninae and Acheilognathinae, and Barbini contains Schizothoracinae, Barbinae, Cyprininae and Labeoninae. Danio rerio, D.myersi and Rasbora trilineata were supposed to separate from Leuciscinae and Barbini and to form another lineage. The positions of some Danioninae species were still unresolved. Analyses of both amino acid variation with parsimony information and two high variation regions indicated that there is no correlation between variations of single amino acid or high variation regions and characteristic size of cyprinids. In addition, the species with smaller size were usually found to be basal within clades in the tree, which might be the results of the adaptation to the primitive ecology and survival pressure.

  6. c-myc and N-myc promote active stem cell metabolism and cycling as architects of the developing brain.

    Science.gov (United States)

    Wey, Alice; Knoepfler, Paul S

    2010-06-01

    myc genes are associated with a wide variety of human cancers including most types of nervous system tumors. While the mechanisms by which myc overexpression causes tumorigenesis are multifaceted and have yet to be clearly elucidated, they are at least in part related to endogenous myc function in normal cells. Knockout (KO) of either c-myc or N-myc genes in neural stem and precursor cells (NSC) driven by nestin-cre impairs mouse brain growth and mutation of N-myc also causes microcephaly in humans in Feingold Syndrome. To further define myc function in NSC and nervous system development, we created a double KO (DKO) for c- and N-myc using nestin-cre. The DKO mice display profoundly impaired overall brain growth associated with decreased cell cycling and migration of NSC, which are strikingly decreased in number. The DKO brain also exhibits specific changes in gene expression including downregulation of genes involved in protein and nucleotide metabolism, mitosis, and chromatin structure as well as upregulation of genes associated with differentiation. Together these data support a model of nervous system tumorigenesis in which excess myc aberrantly locks in a developmentally active chromatin state characterized by overactive cell cycling, and metabolism as well as blocked differentiation.

  7. Ruthenium(II) complexes as apoptosis inducers by stabilizing c-myc G-quadruplex DNA.

    Science.gov (United States)

    Zhang, Zhao; Wu, Qiong; Wu, Xiao-Hui; Sun, Fen-Yong; Chen, Lan-Mei; Chen, Jin-Chan; Yang, Shu-Ling; Mei, Wen-Jie

    2014-06-10

    Two ruthenium(II) complexes, [Ru(L)2(p-tFMPIP)](ClO4)2 (L = bpy, 1; phen, 2; p-tFMPIP = 2-(4-(trifluoromethyphenyl)-1H-imidazo[4,5f][1,10] phenanthroline)), were prepared by microwave-assisted synthesis technology. The inhibitory activity evaluated by MTT assay shown that 2 can inhibit the growth of MDA-MB-231 cells with inhibitory activity (IC50) of 16.3 μM, which was related to the induction of apoptosis. Besides, 2 exhibit low toxicity against normal HAcat cells. The inhibitory growth activity of both complexes related to the induction of apoptosis was also confirmed. Furthermore, the studies on the interaction of both complexes with c-myc G4 DNA shown that 1 and 2 can stabilize the conformation of c-myc G4 DNA in groove binding mode, which has been rational explained by using DFT theoretical calculation methods. In a word, this type of ruthenium(II) complexes can act as potential apoptosis inducers with low toxicity in clinic by stabilizing c-myc G4 DNA.

  8. An Epigenetic Pathway Regulates Sensitivity of Breast Cancer Cells to HER2 Inhibition via FOXO/c-Myc Axis

    Science.gov (United States)

    Matkar, Smita; Sharma, Paras; Gao, Shubin; Gurung, Buddha; Katona, Bryson W; Liao, Jennifer; Muhammad, Abdul Bari; Kong, Xiang-Cheng; Wang, Lei; Jin, Guanghui; Dang, Chi; Hua, Xianxin

    2016-01-01

    SUMMARY Human epidermal growth factor receptor 2 (HER2) is upregulated in a subset of human breast cancers. However, the cancer cells often quickly develop an adaptive response to HER2 kinase inhibitors. We found that an epigenetic pathway involving MLL2 is crucial for growth of HER2+ cells and MLL2 reduces sensitivity of the cancer cells to a HER2 inhibitor, Lapatinib. Lapatinib-induced FOXO transcription factors, normally tumor-suppressing, paradoxically upregulate c-Myc epigenetically, in concert with a cascade of MLL2-associating epigenetic regulators, to dampen sensitivity of the cancer cells to Lapatinib. An epigenetic inhibitor suppressing c-Myc synergizes with Lapatinib to suppress cancer growth in vivo, partly by repressing the FOXO/c-Myc axis, unraveling an epigenetically regulated FOXO/c-Myc axis as a potential target to improve therapy. PMID:26461093

  9. Absence of missense mutations in activated c-myc genes in avian leukosis virus-induced B-cell lymphomas

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, M.; Hayward, W.S.

    1988-06-01

    The authors determined the nucleotide sequences of two independent DNA clones which contained the activated c-myc genes from avian leukosis virus-induced B-cell lymphomas. Neither of these c-myce genes contained missense mutations. This strongly supports the notion that the c-myc photo-oncogene in avian leukosis virus-induced B-cell lymphomas can be oncogenically activated by altered expression of the gene without a change in the primary structure of the gene product.

  10. hTERT protein expression is independent of clinicopathological parameters and c-Myc protein expression in human breast cancer

    Directory of Open Access Journals (Sweden)

    Meligonis G

    2005-01-01

    Full Text Available Abstract Background Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal length and stability thus leading to cellular immortalisation. The hTERT (human telomerase reverse transcriptase subunit seems to be the rate-limiting determinant of telomerase and knowledge of factors controlling hTERT transcription may be useful in therapeutic strategies. The hTERT promoter contains binding sites for c-Myc and there is some experimental and in vitro evidence that c-Myc may increase hTERT expression. We previously reported no correlation between c-Myc mRNA expression and hTERT mRNA or telomerase activity in human breast cancer. This study aims to examine the correlation between hTERT expression as determined by immunohistochemistry and c-Myc expression, lymph node status, and tumour size and grade in human breast cancer. Materials and methods The immunohistochemical expression of hTERT and c-Myc was investigated in 38 malignant breast tumours. The expression of hTERT was then correlated with the lymph node status, c-Myc expression and other clinicopathological parameters of the tumours. Results hTERT expression was positive in 27 (71% of the 38 tumours. 15 (79% of 19 node positive tumours were hTERT positive compared with 11 (63% of 19 node negative tumours. The expression was higher in node positive tumours but this failed to reach statistical significance (p = 0.388. There was no significant association with tumour size, tumour grade or c-Myc expression. However, hTERT expression correlated positively with patients' age (correlation coefficient = 0.415, p = 0.0097. Conclusion hTERT protein expression is independent of lymph node status, tumour size and grade and c-Myc protein expression in human breast cancer

  11. BAF53 Forms Distinct Nuclear Complexes and Functions as a Critical c-Myc-Interacting Nuclear Cofactor for Oncogenic Transformation

    Science.gov (United States)

    Park, Jeonghyeon; Wood, Marcelo A.; Cole, Michael D.

    2002-01-01

    The c-Myc oncoprotein functions as a transcription factor that can transform normal cells into tumor cells, as well as playing a direct role in normal cell proliferation. The c-Myc protein transactivates cellular promoters by recruiting nuclear cofactors to chromosomal sites through an N-terminal transactivation domain. We have previously reported the identification and functional characterization of four different c-Myc cofactors: TRRAP, hGCN5, TIP49, and TIP48. Here we present the identification and characterization of the actin-related protein BAF53 as a c-Myc-interacting nuclear cofactor that forms distinct nuclear complexes. In addition to the human SWI/SNF-related BAF complex, BAF53 forms a complex with TIP49 and TIP48 and a separate biochemically distinct complex containing TRRAP and a histone acetyltransferase which does not contain TIP60. Using deletion mutants of BAF53, we show that BAF53 is critical for c-Myc oncogenic activity. Our results indicate that BAF53 plays a functional role in c-Myc-interacting nuclear complexes. PMID:11839798

  12. Transient activation of c-MYC expression is critical for efficient platelet generation from human induced pluripotent stem cells.

    Science.gov (United States)

    Takayama, Naoya; Nishimura, Satoshi; Nakamura, Sou; Shimizu, Takafumi; Ohnishi, Ryoko; Endo, Hiroshi; Yamaguchi, Tomoyuki; Otsu, Makoto; Nishimura, Ken; Nakanishi, Mahito; Sawaguchi, Akira; Nagai, Ryozo; Takahashi, Kazutoshi; Yamanaka, Shinya; Nakauchi, Hiromitsu; Eto, Koji

    2010-12-20

    Human (h) induced pluripotent stem cells (iPSCs) are a potentially abundant source of blood cells, but how best to select iPSC clones suitable for this purpose from among the many clones that can be simultaneously established from an identical source is not clear. Using an in vitro culture system yielding a hematopoietic niche that concentrates hematopoietic progenitors, we show that the pattern of c-MYC reactivation after reprogramming influences platelet generation from hiPSCs. During differentiation, reduction of c-MYC expression after initial reactivation of c-MYC expression in selected hiPSC clones was associated with more efficient in vitro generation of CD41a(+)CD42b(+) platelets. This effect was recapitulated in virus integration-free hiPSCs using a doxycycline-controlled c-MYC expression vector. In vivo imaging revealed that these CD42b(+) platelets were present in thrombi after laser-induced vessel wall injury. In contrast, sustained and excessive c-MYC expression in megakaryocytes was accompanied by increased p14 (ARF) and p16 (INK4A) expression, decreased GATA1 expression, and impaired production of functional platelets. These findings suggest that the pattern of c-MYC expression, particularly its later decline, is key to producing functional platelets from selected iPSC clones.

  13. Expression of Wnt-1,beta-catenin and c-myc in Ovarian Epithelial Tumor and Its Implication

    Institute of Scientific and Technical Information of China (English)

    LIN Xiao; HU Zhuo-ying

    2008-01-01

    Objective:To investigate the expression of Wnt-1, beta-catenin and c-myc in normal ovarian epithelial cell and malignant ovarian epithelial tumor. Methods:Immunohistochemical staining with SP method was conducted to identify the expression of Wnt-1,beta-catenin and c-myc in 18 samples of normal epithelial tissue and 34 cases of malignant epithelial tumor of ovary. Results:The expression rate of Wnt-1 and c-myc in malignant epithelial tumors was higher than those in normal epithelial cell(P<0.05).The abnormal expression rate of beta-catenin in malignant ovarian epithelial tumors was higher than that in normal epithelial cell(P<0.05).A significant positive correlation was found between Wnt-1, beta-catenin and c-myc in malignant ovarian epithelial tumor(P<0.05).A significant difierence of expressions of Beta-catenin and C-myc was found between serous and mutinous tumors (P<0.05). Conclusion:The abnormal expression of Wnt-1,beta-catenin and c-myc might indicate the malignant transformation in ovarian epithelial tumors.

  14. Coordinate increase of telomerase activity and c-Myc expression in Helicobacter pylori-associated gastric diseases

    Institute of Scientific and Technical Information of China (English)

    Guo-Xin Zhang; Yan-Hong Gu; Zhi-Quan Zhao; Shun-Fu Xu; Hong-Ji Zhang; Hong-Di Wang; Bo Hao

    2004-01-01

    AIM: To detect the telomerase activity and c-Myc expression in gastric diseases and to examine the relation between these values and Helicobacter pylori (H pylori) as a risk factor for gastric cancer.METHODS: One hundred and seventy-one gastric samples were studied to detect telomerase activity using a telomerase polymerase chain reaction enzyme linked immunosorbent assay (PCR-ELTSA), and c-Myc expression using immunohistochemistry.RESULTS: The telomerase activity and c-Myc expression were higher in cancers (87.69% and 61.54%) than in noncancerous tissues. They were higher in chronic atrophic gastritis with severe intestinal metaplasia (52.38% and 47.62%) than in chronic atrophic gastritis with mild intestinal metaplasia (13.33% and 16.67%). Tn chronic atrophic gastritis with severe intestinal metaplasia, the telomerase activity and c-Myc expression were higher in cases with -H pylori infection (67.86% and 67.86%) than in those without infection (21.43%and 7.14%). c-Myc expression was higher in gastric cancer with H pylori infection (77.27%) than in that without infection (28.57%). The telomerase activity and c-Nyc expression were coordinately up-regulated in H pylori infected gastric cancer and chronic atrophic gastritis with severe intestinal metaplasia.CONCLUSION: H pylori infection may influence both telomerase activity and c-Myc expression in gastric diseases,especially in chronic atrophic gastritis.

  15. In vivo inhibition of c-MYC in myeloid cells impairs tumor-associated macrophage maturation and pro-tumoral activities.

    Directory of Open Access Journals (Sweden)

    Oscar M Pello

    Full Text Available Although tumor-associated macrophages (TAMs are involved in tumor growth and metastasis, the mechanisms controlling their pro-tumoral activities remain largely unknown. The transcription factor c-MYC has been recently shown to regulate in vitro human macrophage polarization and be expressed in macrophages infiltrating human tumors. In this study, we exploited the predominant expression of LysM in myeloid cells to generate c-Myc(fl/fl LysM(cre/+ mice, which lack c-Myc in macrophages, to investigate the role of macrophage c-MYC expression in cancer. Under steady-state conditions, immune system parameters in c-Myc(fl/fl LysM(cre/+ mice appeared normal, including the abundance of different subsets of bone marrow hematopoietic stem cells, precursors and circulating cells, macrophage density, and immune organ structure. In a model of melanoma, however, TAMs lacking c-Myc displayed a delay in maturation and showed an attenuation of pro-tumoral functions (e.g., reduced expression of VEGF, MMP9, and HIF1α that was associated with impaired tissue remodeling and angiogenesis and limited tumor growth in c-Myc(fl/fl LysM(cre/+ mice. Macrophage c-Myc deletion also diminished fibrosarcoma growth. These data identify c-Myc as a positive regulator of the pro-tumoral program of TAMs and suggest c-Myc inactivation as an attractive target for anti-cancer therapy.

  16. C-Myc Protein-Protein and Protein-DNA Interactions: Targets for Therapeutic Intervention.

    Science.gov (United States)

    1996-10-01

    progression through the cell cycle (Jansen-Durr et al., 1993; Luscher and Eisenman, 1990). In the mouse, both the c- and N-Myc genes are essential for... Luscher and Eisenman, 1990), the pathways by which it does so seem to be complex. An essential insight into how c-Myc might perform these functions has...Collum and Alt, 1990; Luscher and Eisenman, 1990). Recent experiments support this idea (Amati et al., 1992; Amin et al., 1993; Gu et al., 1993; Kato et al

  17. Cadmium Activates Multiple Signaling Pathways That Coordinately Stimulate Akt Activity to Enhance c-Myc mRNA Stability.

    Directory of Open Access Journals (Sweden)

    Jia-Shiuan Tsai

    Full Text Available Cadmium is a known environmental carcinogen. Exposure of Cd leads to the activation of several proto-oncogenes in cells. We investigated here the mechanism of c-Myc expression in hepatic cells under Cd treatment. The c-Myc protein and mRNA levels increased in dose- and time-dependent manners in HepG2 cells with Cd treatment. This increase was due to an increase in c-Myc mRNA stability. To explore the mechanism involved in enhancing the mRNA stability, several cellular signaling factors that evoked by Cd treatment were analyzed. PI3K, p38, ERK and JNK were activated by Cd. However, ERK did not participate in the Cd-induced c-Myc expression. Further analysis revealed that mTORC2 was a downstream factor of p38. PI3K, JNK and mTORC2 coordinately activated Akt. Akt was phosphorylated at Thr450 in the untreated cells. Cd treatment led to additional phosphorylation at Thr308 and Ser473. Blocking any of the three signaling factors resulted in the reduction of phosphorylation level at all three Akt sites. The activated Akt phosphorylated Foxo1 and allowed the modified protein to translocate into the cytoplasm. We conclude that Cd-induced accumulation of c-Myc requires the activation of several signaling pathways. The signals act coordinately for Akt activation and drive the Foxo1 from the nucleus to the cytoplasm. Reduction of Foxo1 in the nucleus reduces the transcription of its target genes that may affect c-Myc mRNA stability, resulting in a higher accumulation of the c-Myc proteins.

  18. bcl-1, bcl-2, p53, c-myc, and lyt-10 analysis in cutaneous lymphomas.

    Science.gov (United States)

    Garatti, S A; Roscetti, E; Trecca, D; Fracchiolla, N S; Neri, A; Berti, E

    1995-01-01

    In the present study we investigated the pathogenetic role of c-myc, bcl-2, and lyt-10 oncogenes, bcl-1 locus, and p53 suppressor gene in a representative panel of cutaneous lymphomas, including 25 cases of cutaneous B cell lymphoma (CBCL) and 29 cases of cutaneous T cell lymphoma (CTCL). In our analysis four cases of CBCL were found rearranged for bcl-2 and two for the bcl-1 locus. Two cases of CTCL and one case of CBCL were found rearranged for lyt-10. No rearrangements of c-myc oncogene were found in CBCL. Analysis of p53 gene showed mutation only in one case of mycosis fungoides in tumoral stage, at codon 163 of p53 gene (TAC-->CAC; Tyr--> Asp). Our data suggest that in primary CBCL bcl-2 oncogenes and bcl-1 locus are rarely involved. Furthermore, in primary CTCL p53 gene is not affected at significant frequency. The occurrence of p53 mutation in a patient affected by mycosis fungoides in tumoral stage may represent an involvement of p53 gene in tumor progression of CTCL, a finding observed in several types of human cancer.

  19. Abnormal expression of c-Myc in human bronchial epithelial cells malignantly transformed by anti-BPDE

    Institute of Scientific and Technical Information of China (English)

    Juan FU; Yiguo JIANG; Xuemin CHEN

    2008-01-01

    Anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) is a metabolite of benzo[a]pyrene (B[a] P) and acts as a potent mutagen in mammalian systems. However, molecular mechanisms related to anti-BPDE-induced carcinogenesis are poorly understood. Here, we investigated the expression of proto-oncogene c-myc in human bronchial epithelial cells (16H BE-T) transformed by exposure to anti-BPDE. The levels ofmRNA and pro-tein of c-M yc were examined in the 16HBE-T and vehicle-treated control cells (16HBE-N) by using different meth-ods respectively, including reverse transcriptase-polymer-ase chain reaction (RT-PCR), quantitative real-time PCR (Q-PCR), western blot and immunocytochemical meth-ods. The level of c-myc mRNA appeared to be signifi-cantly increased in 16HBE-T, as compared with those of the 16H BE-N. Likewise, the expression of c-Myc protein was significantly enhanced as compared with those of the control cells. Moreover, the localization of c-Myc protein shows mainly nuclear staining in 16HBE-T. In conclu-sion, the abnormal expression of c-Myc was present in anti-BPDE malignantly transformed 16HBE cells, which may be involved in the carcinogenesis molecular mech-anism of anti-BPDE.

  20. Effect of c-myc on the ultrastructural structure of cochleae in guinea pigs with noise induced hearing loss

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yu; Zhong, Cuiping [Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China); Hong, Liu [First Division of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China); Wang, Ye; Qiao, Li [Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China); Qiu, Jianhua, E-mail: qiujh@fmmu.edu.cn [Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 Shaanxi Province (China)

    2009-12-18

    Noise over-stimulation may induce hair cells loss and hearing deficit. The c-myc oncogene is a major regulator for cell proliferation, growth, and apoptosis. However, the role of this gene in the mammalian cochlea is still unclear. The study was designed to firstly investigate its function under noise condition, from the aspect of cochlear ultrastructural changes. We had established the adenoviral vector of c-myc gene and delivered the adenovirus suspension into the scala tympani of guinea pigs 4 days before noise exposure. The empty adenoviral vectors were injected as control. Then, all subjects were exposed to 4-kHz octave-band noise at 110 dB SPL for 8 h/day, 3 days consecutively. Auditory thresholds were assessed by auditory brainstem response, prior to and 7 days following noise exposure. On the seventh days after noise exposure, the cochlear sensory epithelia surface was observed microscopically and the cochleae were taken to study the ultrastructural changes. The results indicated that auditory threshold shift after noise exposure was higher in the ears treated with Ad.EGFP than that treated with Ad.c-myc-EGFP. Stereocilia loss and the disarrangement of outer hair cells were observed, with greater changes found in the Ad.EGFP group. Also, the ultrastructure changes were severe in the Ad.EGFP group, but not obvious in the Ad.c-myc-EGFP group. Therefore, c-myc gene might play an unexpected role in hearing functional and morphological protection from acoustic trauma.

  1. Transient in utero knockout (TIUKO of C-MYC affects late lung and intestinal development in the mouse

    Directory of Open Access Journals (Sweden)

    Zhou Pengbo

    2004-04-01

    Full Text Available Abstract Background Developmentally important genes often result in early lethality in knockout animals. Thus, the direct role of genes in late gestation organogenesis cannot be assessed directly. In utero delivery of transgenes was shown previously to result in high efficiency transfer to pulmonary and intestinal epithelial stem cells. Thus, this technology can be used to evaluate late gestation development. Results In utero gene transfer was used to transfer adenovirus with either an antisense c-myc or a C-MYC ubiquitin targeting protein to knockout out c-myc expression in late gestation lung and intestines. Using either antisense or ubiquitin mediated knockout of C-MYC levels in late gestation resulted in similar effects. Decreased complexity was observed in both intestines and lungs. Stunted growth of villi was evident in the intestines. In the lung, hypoplastic lungs with disrupted aveolarization were observed. Conclusions These data demonstrated that C-MYC was required for cell expansion and complexity in late gestation lung and intestinal development. In addition they demonstrate that transient in utero knockout of proteins may be used to determine the role of developmentally important genes in the lungs and intestines.

  2. Depressive Effect of the Antisense Oligonucleotides of C-myc and PCNA on the Proliferation of VSMC

    Institute of Scientific and Technical Information of China (English)

    Qingxian Li; Yanfu Wang; Yuhua Liao; Huiling Zhang; Yanying Jiang

    2007-01-01

    To study the depressive effect of the antisense oligonuceotides (ASODN) of c-myc and proliferating cell nuclear antigen (PCNA) on the proliferation of VSMC.Methods Taking the VSMC obtained from rat aorta thoracalis cultured 4 ~ 8 generation as research object.The objects were divided into three groups to carry out control study:control group,PCNA ASODN group and c-myc ASODN group.The ASODNs' working concentration all were 1:50.The depressive effect of ASODN on VSMC proliferation was investigated by cell counting,MTT and 3H-TdR incorporation assay;PCNA and c-myc expression were detected by immunohistochemical method after transferring PCNA successfully;the corresponding gene was inhibited obviously;compared with control group ( P < 0.05 ).Conclusions PCNA and c-myc might play a considerable role in the VSMC proliferation process.The corresponding gene could be depressed successfully after transferring PCNA and c-myc ASODN into VSMC,and then the proliferation of VSMC was slowed down.This study presented a beneficial proposal and theoretical fundament for atherosclerotic treatment.

  3. Mechanisms for c-myc Induced Mouse Mammary Gland Carcinogenesis and for the Synergistic Role of TGF(alpha) in the Process

    Science.gov (United States)

    2001-07-01

    central CAC(G/A)TG motif (Henriksson & Prendergast 1999). How the c-Myc protein may be Luscher 1996, Amati et al. 1998, Facchini & Penn 1998...Mycl, c-Myc2, and c-MycS can both activate and repress transcription of specific target (Henriksson & Luscher 1996, Facchini & Penn 1998, Xiao genes...deferens Carcinogenesis 21 427-433. leiomyosarcoma of the Syrian hamster. Cancer Research 30 35- Henriksson M & Luscher B 1996 Proteins of the Myc

  4. Modulation of Cellular Migration and Survival by c-Myc through the Downregulation of Urokinase (uPA) and uPA Receptor▿ †

    Science.gov (United States)

    Alfano, Daniela; Votta, Giuseppina; Schulze, Almut; Downward, Julian; Caputi, Mario; Stoppelli, Maria Patrizia; Iaccarino, Ingram

    2010-01-01

    It has been proposed that c-Myc proapoptotic activity accounts for most of its restraint of tumor formation. We established a telomerase-immortalized human epithelial cell line expressing an activatable c-Myc protein. We found that c-Myc activation induces, in addition to increased sensitivity to apoptosis, reductions in cell motility and invasiveness. Transcriptome analysis revealed that urokinase (uPA) and uPA receptor (uPAR) were strongly downregulated by c-Myc. Evidence is provided that the repression of uPA and uPAR may account for most of the antimigratory and proapoptotic activities of c-Myc. c-Myc is known to cooperate with Ras in cellular transformation. We therefore investigated if this cooperation could converge in the control of uPA/uPAR expression. We found that Ras is able to block the effects of c-Myc activation on apoptosis and cellular motility but not on cell invasiveness. Accordingly, the activation of c-Myc in the context of Ras expression had only minor influence on uPAR expression but still had a profound repressive effect on uPA expression. Thus, the differential regulation of uPA and uPAR by c-Myc and Ras correlates with the effects of these two oncoproteins on cell motility, invasiveness, and survival. In conclusion, we have discovered a novel link between c-Myc and uPA/uPAR. We propose that reductions of cell motility and invasiveness could contribute to the inhibition of tumorigenesis by c-Myc and that the regulation of uPA and uPAR expression may be a component of the ability of c-Myc to reduce motility and invasiveness. PMID:20123981

  5. Modulation of cellular migration and survival by c-Myc through the downregulation of urokinase (uPA) and uPA receptor.

    Science.gov (United States)

    Alfano, Daniela; Votta, Giuseppina; Schulze, Almut; Downward, Julian; Caputi, Mario; Stoppelli, Maria Patrizia; Iaccarino, Ingram

    2010-04-01

    It has been proposed that c-Myc proapoptotic activity accounts for most of its restraint of tumor formation. We established a telomerase-immortalized human epithelial cell line expressing an activatable c-Myc protein. We found that c-Myc activation induces, in addition to increased sensitivity to apoptosis, reductions in cell motility and invasiveness. Transcriptome analysis revealed that urokinase (uPA) and uPA receptor (uPAR) were strongly downregulated by c-Myc. Evidence is provided that the repression of uPA and uPAR may account for most of the antimigratory and proapoptotic activities of c-Myc. c-Myc is known to cooperate with Ras in cellular transformation. We therefore investigated if this cooperation could converge in the control of uPA/uPAR expression. We found that Ras is able to block the effects of c-Myc activation on apoptosis and cellular motility but not on cell invasiveness. Accordingly, the activation of c-Myc in the context of Ras expression had only minor influence on uPAR expression but still had a profound repressive effect on uPA expression. Thus, the differential regulation of uPA and uPAR by c-Myc and Ras correlates with the effects of these two oncoproteins on cell motility, invasiveness, and survival. In conclusion, we have discovered a novel link between c-Myc and uPA/uPAR. We propose that reductions of cell motility and invasiveness could contribute to the inhibition of tumorigenesis by c-Myc and that the regulation of uPA and uPAR expression may be a component of the ability of c-Myc to reduce motility and invasiveness.

  6. Changes in the phenotype of human small cell lung cancer cell lines after transfection and expression of the c-myc proto-oncogene.

    Science.gov (United States)

    Johnson, B E; Battey, J; Linnoila, I; Becker, K L; Makuch, R W; Snider, R H; Carney, D N; Minna, J D

    1986-01-01

    Small cell lung cancer growing in cell culture possesses biologic properties that allow classification into two categories: classic and variant. Compared with classic small cell lung cancer cell lines, variant lines have altered large cell morphology, shorter doubling times, higher cloning efficiencies in soft agarose, and very low levels of L dopa decarboxylase production and bombesin-like immunoreactivity. C-myc is amplified and expressed in some small cell lung cancer cell lines and all c-myc amplified lines studied to date display the variant phenotype. To investigate if c-myc amplification and expression is responsible for the variant phenotype, a normal human c-myc gene was transfected into a cloned classic small cell lung cancer cell line not amplified for or expressing detectable c-myc messenger RNA (mRNA). Clones were isolated with one to six copies of c-myc stably integrated into DNA that expressed c-myc mRNA. In addition, one clone with an integrated neo gene but a deleted c-myc gene was isolated and in this case c-myc was not expressed. C-myc expression in transfected clones was associated with altered large cell morphology, a shorter doubling time, and increased cloning efficiency, but no difference in L dopa decarboxylase levels and bombesin-like immunoreactivity. We conclude increased c-myc expression observed here in transfected clones correlates with some of the phenotypic properties distinguishing c-myc amplified variants from unamplified classic small cell lung cancer lines. Images PMID:3016030

  7. Combined loss of PUMA and p21 accelerates c-MYC-driven lymphoma development considerably less than loss of one allele of p53.

    Science.gov (United States)

    Valente, L J; Grabow, S; Vandenberg, C J; Strasser, A; Janic, A

    2016-07-21

    The tumor suppressor p53 is mutated in ~50% of human cancers. P53 is activated by a range of stimuli and regulates several cellular processes, including apoptotic cell death, cell cycle arrest, senescence and DNA repair. P53 induces apoptosis via transcriptional induction of the BH3-only proteins PUMA (p53-upregulated modulator of apoptosis) and NOXA, and cell cycle arrest via p21. Induction of these processes was proposed to be critical for p53-mediated tumor suppression. It is therefore surprising that mice lacking PUMA, NOXA and p21, as well as mice bearing mutations in p53 that impair the transcriptional activation of these genes, are not tumor prone, unlike mice lacking p53 function, which spontaneously develop tumors with 100% incidence. These p53 target genes and the processes they regulate may, however, impact differently on tumor development depending on the oncogenic drivers. For example, loss of PUMA enhances c-MYC-driven lymphoma development in mice, but, interestingly, the acceleration was less impressive compared with that caused by the loss of even a single p53 allele. Different studies have reported that loss of p21 can accelerate, delay or have no impact on tumorigenesis. In an attempt to resolve this controversy, we examined whether loss of p21-mediated cell cycle arrest cooperates with PUMA deficiency in accelerating lymphoma development in Eμ-Myc mice (overexpressing c-MYC in B-lymphoid cells). We found that Eμ-Myc mice lacking both p21 and PUMA (Eμ-Myc;Puma(-/-);p21(-/-)) developed lymphoma at a rate comparable to Eμ-Myc;Puma(-/-) animals, notably with considerably longer latency than Eμ-Myc;p53(+/-)mice. Loss of p21 had no impact on the numbers, cycling or survival of pre-leukemic Eμ-Myc B-lymphoid cells, even when PUMA was lost concomitantly. These results demonstrate that even in the context of deregulated c-MYC expression, p53 must suppress tumor development by activating processes apart from, or in addition to, PUMA

  8. Correlation of Epstein-Barr virus and its encoded proteins with Helicobacter pylori and expression of c-met and c-myc in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Bing Luo; Yun Wang; Xiao-Feng Wang; Yu Gao; Bao-Hua Huang; Peng Zhao

    2006-01-01

    EBV and H pylori infection. The c-met overexpression was significantly higher in the EBVaGC group than in the EBVnGC group. However,c-met and c-myc expression did not show significant difference between the two groups. Transcripts of EBNA1 were detected in all 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected. Six of the 13 cases exhibited BARF1 transcripts and 2 exhibited BHRF1 transcripts.CONCLUSION: The positivity of H pylori in EBVnGCs is higher than that of EBVaGCs, but no significant correlation is found between EBV infection andH pylori infection. H pylori-positive gastric carcinoma is predominant in antrum location, while EBVaGC has a tendency of predominance in cardia/body location.EBV infection is associated with c-met abnormal expression but not with c-myc protein in EBVaGC. C-met overexpression is not induced by LMP1. BARF1 and BHRF1 may play important roles in the tumorigenesis of EBVaGC through different pathways.

  9. Specific regulation of mRNA cap methylation by the c-Myc and E2F1 transcription factors

    Science.gov (United States)

    Cole, Michael D.; Cowling, Victoria H.

    2009-01-01

    Methylation of the mRNA 5′ guanosine cap is essential for efficient gene expression. The 5′methyl cap binds to eIF4E, which is the first step in the recruitment of mRNA to the 40S ribosomal subunit. To investigate whether mRNA cap methylation is regulated in a gene-specific manner, we established a method to detect the relative level of cap methylation on specific mRNAs. We found that two transcription factors, c-Myc and E2F1, induce cap methylation of their transcriptional target genes, and therefore, c-Myc and E2F1 upregulate gene expression by simultaneously inducing transcription and promoting translation. c-Myc-induced cap methylation is greater than transcriptional induction for the majority of its target genes, indicating that this is a major mechanism by which Myc regulates gene expression. PMID:19137018

  10. Alterations of C-MYC, NKX3.1, and E-cadherin expression in canine prostate carcinogenesis

    DEFF Research Database (Denmark)

    Fonseca-Alves, Carlos E; Rodrigues, Marcela M P; de Moura, Veridiana M B D;

    2013-01-01

    therapies. In humans, the PCa frequently exhibits mutations in the C-MYC and a reduced expression of the E-cadherin and NKX3.1 proteins. This study's objective was to evaluate the NKX3.1, C-MYC, and E-cadherin expression in the canine normal prostate, benign prostatic hyperplasia (BPH), proliferative......The dog (canis lupus familiaris) is the only other species besides humans that develop spontaneous prostatic carcinomas (PCa) at a high frequency. The canine model is primarily utilized for the study of the PCa molecular mechanisms and provides a natural animal model for the study of potential...... inflammatory atrophy (PIA) and PCa and to verify differences in expression and subcellular localization of these proteins in the prostatic carcinogenesis. A tissue microarray (TMA) slide was constructed, and immunohistochemistry with antibodies raised against C-MYC, NKX3.1, E-cadherin and p63 was performed...

  11. c-Myc modulates glucose metabolism via regulation of miR-184/PKM2 pathway in clear-cell renal cell carcinoma.

    Science.gov (United States)

    Huang, Jiwei; Kong, Wen; Zhang, Jin; Chen, Yonghui; Xue, Wei; Liu, Dongming; Huang, Yiran

    2016-10-01

    Renal cell carcinoma (RCC) is one of the most malignant tumors worldwide. Among all subtypes of RCC, clear-cell RCC (ccRCC) is the most common and aggressive one. The difficulty in overcoming resistance of traditional treatment is a threat for ccRCC therapies. Therefore, to understand the mechanism that underlies ccRCC progression is critical for new drug development. In the present study, we identified that miR-184 could be downregulated by c-Myc, which is different from the standard opinion that c-Myc is a target of miR-184. Overexpression of pre-miR-184 changed the metabolic and proliferation features of ccRCC cells by reducing cell glucose consumption, lactate production and cell proliferation. Further analysis by computer bioinformatics revealed that PKM2 is a target of miR-184. Both PKM2 mRNA and protein were significantly affected by addition of miR-184. Importantly, the PKM2 expression level was indeed increased in ccRCC samples, which is totally reverse compared to the decreased miR-184 expression level. Interestingly, we found that when PKM2 was knocked down in ccRCC cells, the rapid proliferation, high glucose consumption and high lactate production were all clearly inhibited, which indicates metabolic reprogramming and cancer progression blocking the in ccRCC cells. Our findings shed new light on ccRCC molecular study and provide a new and solid basis for developing ccRCC therapy.

  12. Elevation of c-MYC disrupts HLA class II-mediated immune recognition of human B cell tumors.

    Science.gov (United States)

    God, Jason M; Cameron, Christine; Figueroa, Janette; Amria, Shereen; Hossain, Azim; Kempkes, Bettina; Bornkamm, Georg W; Stuart, Robert K; Blum, Janice S; Haque, Azizul

    2015-02-15

    Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B cell lymphomas. Although many of c-MYC's functions have been elucidated, its effect on the presentation of Ag through the HLA class II pathway has not been reported previously. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report in this paper that increased c-MYC expression has a negative effect on the ability of B cell lymphomas to functionally present Ags/peptides to CD4(+) T cells. This defect was associated with alterations in the expression of distinct cofactors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt's lymphoma (BL) tumors and transformed cells, we show that compared with B lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47-kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation, which contribute to the immunoevasive properties of BL tumors.

  13. Thermal injuries induce gene expression of endogenous c-fos, c-myc and bFGF in burned tissues

    Institute of Scientific and Technical Information of China (English)

    付小兵; 顾小曼; 孙同柱; 杨银辉; 孙晓庆; 盛志勇

    2003-01-01

    Objective To investigate the expression sequence and distribution characteristics of the protooncogenes c-fos, c-myc and endogenous basic fibroblast growth factor (bFGF ) genes in burned tissues, and to explore the possible effects of changes in the se genes' functions on wound healing. Methods Partial-thickness burns of 30% TBSA were established on backs of Wistar rats. Insitu hybridization and histological methods were used to detect expression of c-fos, c-myc and bFGF genes in normal and burned tissue at 3 h, 6 h, 1 d, 3 d , 7 d and 14 d postburn. Results Although expression of c-fos and c-myc genes and bFGF gene could be found in normal skin, the expression of all three were markedly induced by burn wounds and the expression models in sequence and distribution were quite different. Expre ssion of c-fos gene increased and peaked at 6 h. Signals were mainly localiz ed in both nuclei of dermal fibroblasts and monocytes. The expression of bFGF gene increased at 6 h and peaked at 1 d postburn, and was distributed in the cyt oplasm of fibroblasts. C-myc gene peaked 3 d postburn and was also distributed in the cytoplasm of fibroblasts. Conclusions These results indicated that thermal injury could induce the expression of c-fos, c-myc and bFGF at gene level, showing phasic control and regional distributi on. The phasic expression of these genes suggests that there is an interaction between protooncogenes and bFGF, which may play an important role in wound heali ng. The different expressions of c-fos and c-myc play an inducing role in reg ulating bFGF, and in turn affect wound healing.

  14. EFFECT OF STENT ABSORBED c-myc ANTISENSE OLIGODEOXYNUCLEOTIDE ON SMOOTH MUSCLE CELLS APOPTOSIS IN RABBIT CAROTID ARTERY

    Institute of Scientific and Technical Information of China (English)

    张新霞; 崔长琮; 李江; 崔翰斌; 徐仓宝; 朱参战

    2002-01-01

    Objective To investigate the effect of gelatin coated Platinium-Iridium stent absorbed c-myc antisense oligodeoxynucleotide (ASODN) on smooth muscle cells apoptosis in a normal rabbit carotid arteries. Methods Gelatin coated Platinium-Iridium stents were implanted in the right carotid arteries of 32 rabbits under vision. Animals were randomly divided into control group and treated group receiving c-myc ASODN (n=16, respectively). On 7, 14, 30 and 90 days following the stenting procedure ,morphometry for caculation of neointimal area and mean neointimal thickness were performed.The expression of c-myc protein was detected by immunohistochemical method. Apoptotic smooth muscle cells was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL). Results At 7 and 14 days after stenting,there were no detectable apoptotic cells in both groups. The apoptotic cells occurred in the neointima 30 and 90 days after stenting, and the number of apoptotic cells at 30 days were less [4.50±1.29 vs 25.75±1.89 (number/0.1mm2)] than that at 90 days [13.50±1.91 vs 41.50±6.46 (number/0.1mm2)]. Meanwhile c-myc ASODN induced more apoptotic cells than the control group(P<0.0001). c-myc protein expression was weak positive or negative in treated group and positive in control group.Conclusion c-myc ASODN can induce smooth muscle cells apoptosis after stenting in normal rabbit carotid arteries,and it can be used to prevent in-stent restenosis.

  15. The Max b-HLH-LZ can transduce into cells and inhibit c-Myc transcriptional activities.

    Science.gov (United States)

    Montagne, Martin; Beaudoin, Nicolas; Fortin, David; Lavoie, Christine L; Klinck, Roscoe; Lavigne, Pierre

    2012-01-01

    The inhibition of the functions of c-Myc (endogenous and oncogenic) was recently shown to provide a spectacular therapeutic index in cancer mouse models, with complete tumor regression and minimal side-effects in normal tissues. This was achieved by the systemic and conditional expression of omomyc, the cDNA of a designed mutant of the b-HLH-LZ of c-Myc named Omomyc. The overall mode of action of Omomyc consists in the sequestration of Max and the concomitant competition of the Omomyc/Max complex with the endogenous c-Myc/Max heterodimer. This leads to the inhibition of the transactivation of Myc target genes involved in proliferation and metabolism. While this body of work has provided extraordinary insights to guide the future development of new cancer therapies that target c-Myc, Omomyc itself is not a therapeutic agent. In this context, we sought to exploit the use of a b-HLH-LZ to inhibit c-Myc in a cancer cell line in a more direct fashion. We demonstrate that the b-HLH-LZ domain of Max (Max*) behaves as a bona fide protein transduction domain (PTD) that can efficiently transduce across cellular membrane via through endocytosis and translocate to the nucleus. In addition, we show that the treatment of HeLa cells with Max* leads to a reduction of metabolism and proliferation rate. Accordingly, we observe a decrease of the population of HeLa cells in S phase, an accumulation in G1/G0 and the induction of apoptosis. In agreement with these phenotypic changes, we show by q-RT-PCR that the treatment of HeLa cells with Max* leads to the activation of the transcription c-Myc repressed genes as well as the repression of the expression of c-Myc activated genes. In addition to the novel discovery that the Max b-HLH-LZ is a PTD, our findings open up new avenues and strategies for the direct inhibition of c-Myc with b-HLH-LZ analogs.

  16. The Max b-HLH-LZ can transduce into cells and inhibit c-Myc transcriptional activities.

    Directory of Open Access Journals (Sweden)

    Martin Montagne

    Full Text Available The inhibition of the functions of c-Myc (endogenous and oncogenic was recently shown to provide a spectacular therapeutic index in cancer mouse models, with complete tumor regression and minimal side-effects in normal tissues. This was achieved by the systemic and conditional expression of omomyc, the cDNA of a designed mutant of the b-HLH-LZ of c-Myc named Omomyc. The overall mode of action of Omomyc consists in the sequestration of Max and the concomitant competition of the Omomyc/Max complex with the endogenous c-Myc/Max heterodimer. This leads to the inhibition of the transactivation of Myc target genes involved in proliferation and metabolism. While this body of work has provided extraordinary insights to guide the future development of new cancer therapies that target c-Myc, Omomyc itself is not a therapeutic agent. In this context, we sought to exploit the use of a b-HLH-LZ to inhibit c-Myc in a cancer cell line in a more direct fashion. We demonstrate that the b-HLH-LZ domain of Max (Max* behaves as a bona fide protein transduction domain (PTD that can efficiently transduce across cellular membrane via through endocytosis and translocate to the nucleus. In addition, we show that the treatment of HeLa cells with Max* leads to a reduction of metabolism and proliferation rate. Accordingly, we observe a decrease of the population of HeLa cells in S phase, an accumulation in G1/G0 and the induction of apoptosis. In agreement with these phenotypic changes, we show by q-RT-PCR that the treatment of HeLa cells with Max* leads to the activation of the transcription c-Myc repressed genes as well as the repression of the expression of c-Myc activated genes. In addition to the novel discovery that the Max b-HLH-LZ is a PTD, our findings open up new avenues and strategies for the direct inhibition of c-Myc with b-HLH-LZ analogs.

  17. c-Myc affects mRNA translation, cell proliferation and progenitor cell function in the mammary gland

    Directory of Open Access Journals (Sweden)

    Trumpp Andreas

    2009-09-01

    Full Text Available Abstract Background The oncoprotein c-Myc has been intensely studied in breast cancer and mouse mammary tumor models, but relatively little is known about the normal physiological role of c-Myc in the mammary gland. Here we investigated functions of c-Myc during mouse mammary gland development using a conditional knockout approach. Results Generation of c-mycfl/fl mice carrying the mammary gland-specific WAPiCre transgene resulted in c-Myc loss in alveolar epithelial cells starting in mid-pregnancy. Three major phenotypes were observed in glands of mutant mice. First, c-Myc-deficient alveolar cells had a slower proliferative response at the start of pregnancy, causing a delay but not a block of alveolar development. Second, while milk composition was comparable between wild type and mutant animals, milk production was reduced in mutant glands, leading to slower pup weight-gain. Electron microscopy and polysome fractionation revealed a general decrease in translational efficiency. Furthermore, analysis of mRNA distribution along the polysome gradient demonstrated that this effect was specific for mRNAs whose protein products are involved in milk synthesis. Moreover, quantitative reverse transcription-polymerase chain reaction analysis revealed decreased levels of ribosomal RNAs and ribosomal protein-encoding mRNAs in mutant glands. Third, using the mammary transplantation technique to functionally identify alveolar progenitor cells, we observed that the mutant epithelium has a reduced ability to repopulate the gland when transplanted into NOD/SCID recipients. Conclusion We have demonstrated that c-Myc plays multiple roles in the mouse mammary gland during pregnancy and lactation. c-Myc loss delayed, but did not block proliferation and differentiation in pregnancy. During lactation, lower levels of ribosomal RNAs and proteins were present and translation was generally decreased in mutant glands. Finally, the transplantation studies suggest a role

  18. USP10 Antagonizes c-Myc Transcriptional Activation through SIRT6 Stabilization to Suppress Tumor Formation

    Directory of Open Access Journals (Sweden)

    Zhenghong Lin

    2013-12-01

    Full Text Available The reduced protein expression of SIRT6 tumor suppressor is involved in tumorigenesis. The molecular mechanisms underlying SIRT6 protein downregulation in human cancers remain unknown. Using a proteomic approach, we have identified the ubiquitin-specific peptidase USP10, another tumor suppressor, as one of the SIRT6-interacting proteins. USP10 suppresses SIRT6 ubiquitination to protect SIRT6 from proteasomal degradation. USP10 antagonizes the transcriptional activity of the c-Myc oncogene through SIRT6, as well as p53, to inhibit cell-cycle progression, cancer cell growth, and tumor formation. To support this conclusion, we detected significant reductions in both USP10 and SIRT6 protein expression in human colon cancers. Our study discovered crosstalk between two tumor-suppressive genes in regulating cell-cycle progression and proliferation and showed that dysregulated USP10 function promotes tumorigenesis through SIRT6 degradation.

  19. c-myc mRNA in cytoskeletal-bound polysomes in fibroblasts.

    Science.gov (United States)

    Hesketh, J E; Campbell, G P; Whitelaw, P F

    1991-03-01

    3T3 fibroblasts were treated sequentially with 25 mM-KCl/0.05% Nonidet P40, 130 mM-KCl/0.05% Nonidet P40 and finally with 1% Nonidet P40/1% deoxycholate in order to release free, cytoskeletal-bound and membrane-bound polysomes respectively. The membrane-bound fraction was enriched in the mRNA for the membrane protein beta 2-microglobulin, whereas the cytoskeletal-bound polysomes were enriched in c-myc mRNA. Actin mRNA was present in both free and cytoskeletal-bound polysomes. The results suggest that cytoskeletal-bound polysomes are involved in the translation of specific mRNA species.

  20. Molecular characterizations of Nop16 in murine mammary tumors with varying levels of c-Myc.

    Science.gov (United States)

    Kundel, Donald W; Stromquist, Emily; Greene, Amy L; Zhdankin, Olga; Regal, Ronald R; Rose-Hellekant, Teresa A

    2012-04-01

    NOP16, also known as HSPC111, has been identified as a MYC and estrogen regulated gene in in vitro studies, hence coexpression levels were strongly correlated. Importantly, high expression of NOP16 was associated with poor clinical outcome in breast cancer patients. However, coexpression of NOP16, MYC and estrogen receptor (ESR1) varied widely in tumors and cell lines suggesting that transcriptional regulation differed according to pathological environments. The goal of this study was to determine the expression patterns of Nop16, Myc and Esr1 in murine mammary tumors with disparate histopathological and molecular features. We hypothesized that tumor environments with relatively high Myc levels would have different coexpression patterns than tumor environments with relatively low Myc levels. We measured levels of Myc and Nop16 mRNA and protein in tumors from WAP-c-myc mice that were of high grade and metastasized frequently. In contrast, Myc and Nop16 mRNA and proteins levels were significantly lower in the less aggressive tumors that developed in NRL-TGFα mice. Tumors from both mouse lines express ESR1 protein and we found that Esr1 mRNA levels correlated positively with Myc levels in both models. However, Myc and Nop16 transcript levels correlated positively only in tumors from NRL-TGFα mice. We identified prominent NOP16 protein in nuclei and less prominent staining in the cytoplasm of luminal cells of ducts and lobules from normal mammary glands as well as in hyperplasias and tumors obtained from NRL-TGFα mice. This staining pattern was reversed in tumors from WAP-c-Myc mice as nuclear staining was faint or absent and cytoplasmic staining more pronounced. In summary, the regulation of expression and localization of NOP16 varies in tumor environments with high versus low MYC levels and demonstrate the importance of stratifying clinical breast cancers based on MYC levels.

  1. c-Myc regulates proliferation and Fgf10 expression in airway smooth muscle after airway epithelial injury in mouse.

    Directory of Open Access Journals (Sweden)

    Thomas Volckaert

    Full Text Available During lung development, Fibroblast growth factor 10 (Fgf10, which is expressed in the distal mesenchyme and regulated by Wnt signaling, acts on the distal epithelial progenitors to maintain them and prevent them from differentiating into proximal (airway epithelial cells. Fgf10-expressing cells in the distal mesenchyme are progenitors for parabronchial smooth muscle cells (PSMCs. After naphthalene, ozone or bleomycin-induced airway epithelial injury, surviving epithelial cells secrete Wnt7b which then activates the PSMC niche to induce Fgf10 expression. This Fgf10 secreted by the niche then acts on a subset of Clara stem cells to break quiescence, induce proliferation and initiate epithelial repair. Here we show that conditional deletion of the Wnt target gene c-Myc from the lung mesenchyme during development does not affect proper epithelial or mesenchymal differentiation. However, in the adult lung we show that after naphthalene-mediated airway epithelial injury c-Myc is important for the activation of the PSMC niche and as such induces proliferation and Fgf10 expression in PSMCs. Our data indicate that conditional deletion of c-Myc from PSMCs inhibits airway epithelial repair, whereas c-Myc ablation from Clara cells has no effect on airway epithelial regeneration. These findings may have important implications for understanding the misregulation of lung repair in asthma and COPD.

  2. Telomerase in relation to expression of p53, c-Myc and estrogen receptor in ovarian tumours

    NARCIS (Netherlands)

    Wisman, GBA; Hollema, H; Helder, MN; Knol, AJ; Van Der Meer, GT; Krans, M; De Jong, S; De Vries, EGE; Van Der Zee, AGJ

    2003-01-01

    Telomerase activity and its subunits (hTERC, hTERT mRNA) were evaluated in ovarian tumours in relation to the expression of p53, c-Myc and estrogen receptor (ER). Furthermore, relations between telomerase activity, hTERC and hTERT with known clinicopathologic prognostic factors and survival in patie

  3. Induction of endogenous telomerase (hTERT) by c-Myc in WI-38 fibroblasts transformed with specific genetic elements.

    Science.gov (United States)

    Casillas, Mark A; Brotherton, Scott L; Andrews, Lucy G; Ruppert, J Michael; Tollefsbol, Trygve O

    2003-10-16

    Elucidation of the mechanisms governing expression of the human telomerase reverse transcriptase (hTERT) is important for understanding cancer pathogenesis. Approximately 90% of tumors express hTERT, the major catalytic component of telomerase. Activation of telomerase is an early event, and high levels of this activity correlate with poor prognosis. Recent studies have shown that the transcription factors c-Myc and Mad1 activate and repress hTERT, respectively. It is not clear how these transcription factors compete for the same recognition sequence in the hTERT core promoter region. Studies have shown that the combined expression of SV40 large T antigen (T-Ag), hTERT, and H-Ras is able to transform human cells. In this study, we used a distinct human cell type, WI-38 fetal lung fibroblasts used extensively for senescence studies. We transduced cells with amphotropic retroviral constructs containing SV40 T antigen, hTERT, and activated H-ras. Transduced cells exhibited anchorage independence in soft agar and expressed increased levels of c-Myc and endogenous hTERT. These effects were observed by 25 population doublings (PDs) following the establishment of the neoplastic cell line. During the process of transformation, we observed a switch from Mad1/Max to c-Myc/Max binding to oligonucleotide sequences containing the hTERT promoter distal and proximal E-boxes. c-Myc can bind specifically to the hTERT promoter in vitro, indicating that c-Myc expression in tumors may account for the increased expression of hTERT observed in vivo. These findings indicate that the widely used model system of WI-38 fibroblasts can be employed for transformation studies using defined genetic elements and that the endogenous hTERT and c-Myc are induced in these cells during early tumorigenesis. Such studies should have important implications in the mechanisms of hTERT and c-Myc induction in the beginning stages of tumorigenesis and facilitate extension of these studies to novel models of

  4. Wnt/β-catenin signaling regulates Helicoverpa armigera pupal development by up-regulating c-Myc and AP-4.

    Science.gov (United States)

    Chen, Wei; Xu, Wei-Hua

    2014-10-01

    Seasonally changing environmental conditions perceived by insect brains can be converted into hormonal signals that prompt insects to make a decision to develop or enter developmental arrest (diapause). Diapause is a complex physiological response, and many signaling pathways may participate in its regulation. However, little is known about these regulatory pathways. In this study, we cloned four genes related to the Wnt/β-catenin signaling pathway from Helicoverpa armigera, a pupal diapause species. Western blotting shows that expression of Har-Wnt1, Har-β-catenin, and Har-c-Myc are higher in non-diapause pupal brains than in diapause-destined brains. Har-Wnt1 can promote the accumulation of Har-β-catenin in the nucleus, and Har-β-catenin in turn increases the expression of Har-c-Myc. The blockage of Wnt/β-catenin signaling by the inhibitor XAV939 significantly down-regulates Har-β-catenin and Har-c-Myc expression and delays pupal development, suggesting that the Wnt/β-catenin pathway functions in insect development. Furthermore, Har-c-Myc binds to the promoter of Har-AP-4 and regulates its expression. It has been reported that Har-AP-4 activates diapause hormone (DH) expression and that DH up-regulates the growth hormone ecdysteroid for pupal development. Thus, pupal development is regulated by Wnt/β-catenin signaling through the pathway Wnt-β-catenin-c-Myc-AP-4-DH-ecdysteroid. In contrast, the down-regulation of Wnt/β-catenin signaling is likely to induce insects to enter diapause.

  5. Elevation of c-MYC Disrupts HLA Class II-mediated Immune Recognition of Human B-cell Tumors1

    Science.gov (United States)

    God, Jason M.; Cameron, Christine; Figueroa, Janette; Amria, Shereen; Hossain, Azim; Kempkes, Bettina; Bornkamm, Georg W.; Stuart, Robert K.; Blum, Janice S.; Haque, Azizul

    2014-01-01

    Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B-cell lymphomas. While many of c-MYC’s functions have been elucidated, its effect on the presentation of antigen (Ag) through the HLA class II pathway has not previously been reported. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report here that increased c-MYC expression has a negative effect on the ability of B-cell lymphomas to functionally present Ags/peptides to CD4+ T cells. This defect was associated with alterations in the expression of distinct co-factors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt’s lymphoma (BL) tumors and transformed cells, we show that compared to B-lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation which contribute to the immunoevasive properties of BL tumors. PMID:25595783

  6. K-RAS point mutation, and amplification of C-MYC and C-ERBB2 in colon adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Tadeusz Pawełczyk

    2004-10-01

    Full Text Available The routine multidisciplinary management of colon cancer is based mainly on tumor staging, histology, grading and vascular invasion. In this approach, important individual information derived from molecular characteristics of the tumor may be missed, especially since significant heterogeneity of molecular aberrations in cancer cells has been observed, and recognition of every of relationships between them may be of value. K-RAS, C-MYC and C-ERBB2 are protooncogenes taking part in carcinogenesis and tumor progression in the colon. They influence cell proliferation, differentiation and survival. K-RAS point mutation, as well as amplification of C-MYC and C-ERBB2 were searched in 84 primary colon adenocarcinomas resected with curative intent. Multiplex polymerase-chain reaction and restriction fragment length polymorphism were performed to assess codon 12 K-RAS point mutation. Amplification of C-MYC and C-ERBB2 genes was evaluated by densitometry after agarose gel separation of the respective multiplex PCR products. No relation was found among mutated and/or amplified genes, and between searched molecular aberrations and pathoclinical features. In multivariate analysis, nodal status appeared to be the only independent prognostic indicator. In colon adenocarcinoma, codon 12 K-RAS point mutation and amplification of C-MYC and C-ERBB2 seem to occur independently in the process of tumor progression. Amplification of C-ERBB2 tends to associate with more advanced stage of disease. Concomitant occurrence of codon 12 K-RAS mutation, C-MYC and C-ERBB2 amplification was of no prognostic value in respect to survival.

  7. Clinical significance of high c-MYC and low MYCBP2 expression and their association with Ikaros dysfunction in adult acute lymphoblastic leukemia.

    Science.gov (United States)

    Ge, Zheng; Guo, Xing; Li, Jianyong; Hartman, Melanie; Kawasawa, Yuka Imamura; Dovat, Sinisa; Song, Chunhua

    2015-12-01

    Increased expression of c-MYC is observed in both Acute Myeloid Leukemia (AML) and T-cell Acute Lymphoblastic Leukemia (T-ALL). MYC binding protein 2 (MYCBP2) is a probable E3 ubiquitin ligase and its function in leukemia is unknown. IKZF1 deletion is associated with the development and poor outcome of ALL. Here, we observed significant high c-MYC expression and low MYCBP2 expression in adult ALL patients. Patients with high c-MYC expression and/or low MYCBP2 expression had higher WBC counts and a higher percentage of CD34+ or CD33+ cells, as well as splenomegaly, liver infiltration, higher BM blasts, and lower CR rate. Ikaros bound to the regulatory regions of c-MYC and MYCBP2, suppressed c-MYC and increased MYCBP2 expression in ALL cells. Expression of c-MYC mRNA was significantly higher in patients with IKZF1 deletion; conversely MYCBP2 mRNA expression was significantly lower in those patients. A CK2 inhibitor, which acts as an Ikaros activator, also suppressed c-MYC and increased MYCBP2 expression in an Ikaros (IKZF1) dependent manner in the ALL cells. In summary, our data indicated the correlation of high c-MYC expression, low MYCBP2 expression and high c-MYC plus low MYCBP2 expression with high-risk factors and proliferation markers in adult ALL patients. Our data also revealed an oncogenic role for an Ikaros/MYCBP2/c-MYC axis in adult ALL, providing a mechanism of target therapies that activate Ikaros in adult ALL.

  8. A novel role for c-Myc in G protein-coupled receptor kinase 4 (GRK4) transcriptional regulation in human kidney proximal tubule cells.

    Science.gov (United States)

    Gildea, John J; Tran, Hanh T; Van Sciver, Robert E; Bigler Wang, Dora; Carlson, Julia M; Felder, Robin A

    2013-05-01

    The G protein-coupled receptor kinase 4 (GRK4) negatively regulates the dopaminergic system by desensitizing the dopamine-1-receptor. The expressional control of GRK4 has not been reported, but here we show that the transcription factor c-Myc binds to the promoter of GRK4 and positively regulates GRK4 protein expression in human renal proximal tubule cells (RPTCs). Addition of phorbol esters to RPTCs not only increased c-Myc binding to the GRK4 promoter but also increased both phospho-c-Myc and GRK4 expression. The phorbol ester-mediated increase in GRK4 expression was completely blocked by the c-Myc inhibitor, 10074-G5, indicating that GRK4 is downstream of phospho-c-Myc. The autocrine production of angiotensin II (Ang II) in RPTCs increased the phosphorylation and activation of c-Myc and subsequently GRK4 expression. 3-Amino-4-thio-butyl sulfonate, an inhibitor of aminopeptidase A, increased RPTC secretion of Ang II. 3-Amino-4-thio-butyl sulfonate or Ang II increased the expression of both phospho-c-Myc and GRK4, which was blocked by 10074-G5. Blockade of the Ang II type 1 receptor with losartan decreased phospho-c-Myc and GRK4 expression. Both inhibition of c-Myc activity and blockade of Ang II type 1 receptor restored the coupling of dopamine-1-receptor to adenylyl cyclase stimulation in uncoupled RPTCs, whereas phorbol esters or Ang II caused the uncoupling of normally coupled RPTCs. We suggest that the Ang II type 1 receptor impairs dopamine-1-receptor function via c-Myc activation of GRK4. This novel pathway may be involved in the increase in blood pressure in hypertension that is mediated by increased activity of the renin-angiotensin system and decreased activity of the renal dopaminergic system.

  9. Mitochondrial structure, function and dynamics are temporally controlled by c-Myc.

    Directory of Open Access Journals (Sweden)

    J Anthony Graves

    Full Text Available Although the c-Myc (Myc oncoprotein controls mitochondrial biogenesis and multiple enzymes involved in oxidative phosphorylation (OXPHOS, the coordination of these events and the mechanistic underpinnings of their regulation remain largely unexplored. We show here that re-expression of Myc in myc-/- fibroblasts is accompanied by a gradual accumulation of mitochondrial biomass and by increases in membrane polarization and mitochondrial fusion. A correction of OXPHOS deficiency is also seen, although structural abnormalities in electron transport chain complexes (ETC are not entirely normalized. Conversely, the down-regulation of Myc leads to a gradual decrease in mitochondrial mass and a more rapid loss of fusion and membrane potential. Increases in the levels of proteins specifically involved in mitochondrial fission and fusion support the idea that Myc affects mitochondrial mass by influencing both of these processes, albeit favoring the latter. The ETC defects that persist following Myc restoration may represent metabolic adaptations, as mitochondrial function is re-directed away from producing ATP to providing a source of metabolic precursors demanded by the transformed cell.

  10. Suppression of c-Myc induces apoptosis via an AMPK/mTOR-dependent pathway by 4-O-methyl-ascochlorin in leukemia cells.

    Science.gov (United States)

    Shin, Jae-Moon; Jeong, Yun-Jeong; Cho, Hyun-Ji; Magae, Junji; Bae, Young-Seuk; Chang, Young-Chae

    2016-05-01

    4-O-Methyl-ascochlorin (MAC) is a methylated derivative of the prenyl-phenol antibiotic ascochlorin, which was isolated from an incomplete fungus, Ascochyta viciae. Although the effects of MAC on apoptosis have been reported, the underlying mechanisms remain unknown. Here, we show that MAC promoted apoptotic cell death and downregulated c-Myc expression in K562 human leukemia cells. The effect of MAC on apoptosis was similar to that of 10058-F4 (a c-Myc inhibitor) or c-Myc siRNA, suggesting that the downregulation of c-Myc expression plays a role in the apoptotic effect of MAC. Further investigation showed that MAC downregulated c-Myc by inhibiting protein synthesis. MAC promoted the phosphorylation of AMP-activated protein kinase (AMPK) and inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and its target proteins, including p70S6 K and 4E-BP-1. Treatment of cells with AICAR (an AMPK activator), rapamycin (an mTOR inhibitor), or mTOR siRNA downregulated c-Myc expression and induced apoptosis to a similar extent to that of MAC. These results suggest that the effect of MAC on apoptosis induction in human leukemia cells is mediated by the suppression of c-Myc protein synthesis via an AMPK/mTOR-dependent mechanism.

  11. Chromatin dynamics at the hTERT promoter during transcriptional activation and repression by c-Myc and Mnt in Xenopus leavis oocytes.

    Science.gov (United States)

    Wahlström, Therese; Belikov, Sergey; Arsenian Henriksson, Marie

    2013-12-10

    The transcription factors c-Myc and Mnt regulate gene expression through dimerization with Max and binding to E-boxes in target genes. While c-Myc activates gene expression via recruitment of histone modifying complexes, Mnt acts as a transcriptional repressor. Here, we used the Xenopus leavis oocyte system to address the effect of c-Myc and Mnt on transcription and chromatin remodeling over the E-box region in the human telomerase reverse transcriptase (hTERT) promoter. As expected we found elevated and decreased levels of hTERT transcription upon exogenously expressed c-Myc/Max and Mnt/Max, respectively. In addition, we confirmed binding of these heterodimers to both E-boxes already enriched with H3K9ac and H4K16ac. These chromatin marks were further enhanced upon c-Myc/Max binding followed by increased DNA accessibility in the E-box region. In contrast, Mnt/Max inhibited Myc-induced transcription and mediated repression through complete chromatin condensation and deacetylation of H3K9 and H4K16 across the E-box region. Importantly, Mnt was able to counteract c-Myc mediated activation even when expressed at low levels, suggesting Mnt to act as a strong repressor by closing the chromatin structure. Collectively our data demonstrate that the balance between c-Myc and Mnt activity determines the transcriptional outcome of the hTERT promoter by modulation of the chromatin architecture.

  12. Anchoring of c-myc on nuclear matrix proteins in process of mouse thymic T lymphocyte proliferation induced by ConA

    Institute of Scientific and Technical Information of China (English)

    曾丛梅; 蔡树涛; 周凤兰; 张锦珠; 王平

    1996-01-01

    Isolation and characteriation of functional nudear matrix proteins involved in DNA anchoring and gene expression is one of the major subjects of current nudear matrix research. Southwestern blotting (DNA-protein hybridization) was applied to studying the anchoring of c-myc on the nudear matrix proteins in mouse thymic T lymphocytes. The results showed that c-myc bound to the lamin, p34 and p36 nudear matrix proteins specifically. In the process of mouse thymic PNA T lymphocytes proliferation induced by ConA, the anchoring of c-myc on p34 and p36 nudear matrix proteins changed dynamically.

  13. Conserved features of cancer cells define their sensitivity to HAMLET-induced death; c-Myc and glycolysis.

    Science.gov (United States)

    Storm, P; Aits, S; Puthia, M K; Urbano, A; Northen, T; Powers, S; Bowen, B; Chao, Y; Reindl, W; Lee, D Y; Sullivan, N L; Zhang, J; Trulsson, M; Yang, H; Watson, J D; Svanborg, C

    2011-12-01

    HAMLET is the first member of a new family of tumoricidal protein-lipid complexes that kill cancer cells broadly, while sparing healthy, differentiated cells. Many and diverse tumor cell types are sensitive to the lethal effect, suggesting that HAMLET identifies and activates conserved death pathways in cancer cells. Here, we investigated the molecular basis for the difference in sensitivity between cancer cells and healthy cells. Using a combination of small-hairpin RNA (shRNA) inhibition, proteomic and metabolomic technology, we identified the c-Myc oncogene as one essential determinant of HAMLET sensitivity. Increased c-Myc expression levels promoted sensitivity to HAMLET and shRNA knockdown of c-Myc suppressed the lethal response, suggesting that oncogenic transformation with c-Myc creates a HAMLET-sensitive phenotype. Furthermore, HAMLET sensitivity was modified by the glycolytic state of tumor cells. Glucose deprivation sensitized tumor cells to HAMLET-induced cell death and in the shRNA screen, hexokinase 1 (HK1), 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 1 and hypoxia-inducible factor 1α modified HAMLET sensitivity. HK1 was shown to bind HAMLET in a protein array containing ∼8000 targets, and HK activity decreased within 15 min of HAMLET treatment, before morphological signs of tumor cell death. In parallel, HAMLET triggered rapid metabolic paralysis in carcinoma cells. Tumor cells were also shown to contain large amounts of oleic acid and its derivatives already after 15 min. The results identify HAMLET as a novel anti-cancer agent that kills tumor cells by exploiting unifying features of cancer cells such as oncogene addiction or the Warburg effect.

  14. Targeting C-myc G-Quadruplex: Dual Recognition by Aminosugar-Bisbenzimidazoles with Varying Linker Lengths

    Directory of Open Access Journals (Sweden)

    Nihar Ranjan

    2013-11-01

    Full Text Available G-quadruplexes are therapeutically important biological targets. In this report, we present biophysical studies of neomycin-Hoechst 33258 conjugates binding to a G-quadruplex derived from the C-myc promoter sequence. Our studies indicate that conjugation of neomycin to a G-quadruplex binder, Hoechst 33258, enhances its binding. The enhancement in G-quadruplex binding of these conjugates varies with the length and composition of the linkers joining the neomycin and Hoechst 33258 units.

  15. C-MYC-induced upregulation of lncRNA SNHG12 regulates cell proliferation, apoptosis and migration in triple-negative breast cancer.

    Science.gov (United States)

    Wang, Ouchen; Yang, Fan; Liu, Yehuan; Lv, Lin; Ma, Ruimin; Chen, Chuanzhi; Wang, Jiao; Tan, Qiufan; Cheng, Yue; Xia, Erjie; Chen, Yizuo; Zhang, Xiaohua

    2017-01-01

    Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer, with a significantly higher recurrence and mortality rate. There is an urgent need to uncover the mechanism underlying TNBC and establish therapeutic targets. Long non-coding RNAs (lncRNAs) are involved in a series of biological functions and provide novel insights into the molecular mechanism of cancer. Based on their expression specificity and large number, lncRNAs are likely to serve as the basis for clinical applications in oncology. In our previous study, we utilized RNA sequencing (RNA-seq) to explore the lncRNAs expression profiles in TNBC and identified that small nucleolar RNA host gene 12 (SNHG12) was remarkably increased in TNBC. However, the role of SNHG12 in TNBC has not been clarified. Herein, we determine that SNHG12 is upregulated in TNBC, and its high expression is significantly correlated with tumor size and lymph node metastasis. Mechanistic investigations show that SNHG12 is a direct transcriptional target of c-MYC. Silencing SNHG12 expression inhibits TNBC cells proliferation and apoptosis promotion, whereas SNHG12 overexpression has the opposite effect. In addition, we reveal that SNHG12 may promote cells migration by regulating MMP13 expression. To the best of our knowledge, it is the first report indicating that SNHG12 is involved in breast cancer. Taken together, our findings suggest that SNHG12 contributes to the oncogenic potential of TNBC and may be a promising therapeutic target.

  16. A natural small molecule, catechol, induces c-Myc degradation by directly targeting ERK2 in lung cancer.

    Science.gov (United States)

    Lim, Do Young; Shin, Seung Ho; Lee, Mee-Hyun; Malakhova, Margarita; Kurinov, Igor; Wu, Qiong; Xu, Jinglong; Jiang, Yanan; Dong, Ziming; Liu, Kangdong; Lee, Kun Yeong; Bae, Ki Beom; Choi, Bu Young; Deng, Yibin; Bode, Ann; Dong, Zigang

    2016-06-07

    Various carcinogens induce EGFR/RAS/MAPK signaling, which is critical in the development of lung cancer. In particular, constitutive activation of extracellular signal-regulated kinase 2 (ERK2) is observed in many lung cancer patients, and therefore developing compounds capable of targeting ERK2 in lung carcinogenesis could be beneficial. We examined the therapeutic effect of catechol in lung cancer treatment. Catechol suppressed anchorage-independent growth of murine KP2 and human H460 lung cancer cell lines in a dose-dependent manner. Catechol inhibited ERK2 kinase activity in vitro, and its direct binding to the ERK2 active site was confirmed by X-ray crystallography. Phosphorylation of c-Myc, a substrate of ERK2, was decreased in catechol-treated lung cancer cells and resulted in reduced protein stability and subsequent down-regulation of total c-Myc. Treatment with catechol induced G1 phase arrest in lung cancer cells and decreased protein expression related to G1-S progression. In addition, we showed that catechol inhibited the growth of both allograft and xenograft lung cancer tumors in vivo. In summary, catechol exerted inhibitory effects on the ERK2/c-Myc signaling axis to reduce lung cancer tumor growth in vitro and in vivo, including a preclinical patient-derived xenograft (PDX) model. These findings suggest that catechol, a natural small molecule, possesses potential as a novel therapeutic agent against lung carcinogenesis in future clinical approaches.

  17. Proliferation and C-myc Gene Expression of Smooth Muscle Cells in Rabbit Carotid Artery after Stenting

    Institute of Scientific and Technical Information of China (English)

    张新霞; 崔长琮; 胡雪松; 魏文斌; 李松; 许香广

    2004-01-01

    Objectives To investigate the proliferation of smooth muscle cells (VSMCs) and the expression of c-myc gene in rabbit carotid arteries after stenting. Methods Platinium-Iridium stent were implanted into the right carotid arteries of 16 rabbits under vision. 7,14,30 and 90 days after the stenting procedure, morphological changes of VSMCs were observed under light and transmission electron microscope. The c-myc gene expression was detected by in situ hybridization (ISH) and immunohistochemical staining. Results 7 days after stenting, the phenotype of VSMCs changed from contractile to synthetic phenotype; there were a number of proliferative VSMCs in the neointima. At 14 and 30 days, there were synthetic and transitive VSMCs. At 90 days, the phenotype of VSMCs recovered to contractile phenotype.The ultrastructure of typical synthetic phenotype of VSMCs were round, containing a large amount of rough endoplasmic reticulum and mitochondria. Cmyc expression were positive both by ISH and immunohistochemical staining. Conclusions C-myc gene expression increases and closely relates to VSMCs proliferation after stenting. It may play an important role in the in-stent restenosis.

  18. Primary structure and functional scFv antibody expression of an antibody against the human protooncogen c-myc.

    Science.gov (United States)

    Fuchs, P; Breitling, F; Little, M; Dübel, S

    1997-06-01

    The immunoglobulin heavy- and light-chain variable region (Vh and Vl) genes were isolated from Myc1-9E10 hybridoma cells, which secreted monoclonal antibody against human oncogen c-myc. The expression vector pOPE52-c-myc was constructed for the recombinant production in E. coli. A 30 kDa single chain fragment (scFv) expression product was found in the periplasmic space by SDS-PAGE and immunoblotting. A significant fraction was processed correctly as demonstrated with an antiserum recognizing the processed aminoterminus only. The specific binding of the scFv fragment to the peptide epitope of the maternal monoclonal antibody was demonstrated and the primary sequence of the variable regions was determined. Sequence comparison with previously published partial Vh and Vl sequences from this hybridoma cell line revealed a genetic heterogeneity for the light chain variable region. The potential use of this scFv as a new tool for detection and purification of tagged proteins, for adding costimulatory signals to the surface of cancer cells as well as for analyzing c-myc function in the living cell by cytoplasmic expression is discussed.

  19. A natural small molecule, catechol, induces c-Myc degradation by directly targeting ERK2 in lung cancer

    Science.gov (United States)

    Lim, Do Young; Shin, Seung Ho; Lee, Mee-Hyun; Malakhova, Margarita; Kurinov, Igor; Wu, Qiong; Xu, Jinglong; Jiang, Yanan; Dong, Ziming; Liu, Kangdong; Lee, Kun Yeong; Bae, Ki Beom; Choi, Bu Young; Deng, Yibin; Bode, Ann; Dong, Zigang

    2016-01-01

    Various carcinogens induce EGFR/RAS/MAPK signaling, which is critical in the development of lung cancer. In particular, constitutive activation of extracellular signal-regulated kinase 2 (ERK2) is observed in many lung cancer patients, and therefore developing compounds capable of targeting ERK2 in lung carcinogenesis could be beneficial. We examined the therapeutic effect of catechol in lung cancer treatment. Catechol suppressed anchorage-independent growth of murine KP2 and human H460 lung cancer cell lines in a dose-dependent manner. Catechol inhibited ERK2 kinase activity in vitro, and its direct binding to the ERK2 active site was confirmed by X-ray crystallography. Phosphorylation of c-Myc, a substrate of ERK2, was decreased in catechol-treated lung cancer cells and resulted in reduced protein stability and subsequent down-regulation of total c-Myc. Treatment with catechol induced G1 phase arrest in lung cancer cells and decreased protein expression related to G1-S progression. In addition, we showed that catechol inhibited the growth of both allograft and xenograft lung cancer tumors in vivo. In summary, catechol exerted inhibitory effects on the ERK2/c-Myc signaling axis to reduce lung cancer tumor growth in vitro and in vivo, including a preclinical patient-derived xenograft (PDX) model. These findings suggest that catechol, a natural small molecule, possesses potential as a novel therapeutic agent against lung carcinogenesis in future clinical approaches. PMID:27167001

  20. The Influence of Nano-apatite on c-myc and p53 Gene in the Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; CAO Xianying; LI Shipu; HAN Yingchao; ZHANG Ran

    2005-01-01

    The influence mechanism of the nano-apatite on the human hepatocellular carcinoma in vitro was investigated. Using the homogeneous precipitation method, the nano-apatite was synthesized at room temperature, and it was characterized with transmission electron microscopy (TEM) and the Zataplus. The influence on the expression of the c-myc and p53 gene in the human hepatocellular carcinoma cell lines were tested with the TEM and hybridization in situ. The TEM and the Zataplus analyses show that the nano-apatite is distributed homogenously in size and needle-shaped sizes, which ranges from 67.5 nm to 88.3 nm. It is found that the nano-apatitet increases the volume of the human hepatocellular carcinoma cells, makes extensive cytoplasmic vacuolization, the mitochondria swelling, chromatin in nucleus dispersed partially and condensed around the nuclear membranes.The interspace in nuclear membranes were separated and even the cytoplasm dissolved. It is also found that the expression of the c-myc gene is inhibited, but the p53 is enhanced. The experimental results demonstrate that the nano-apatite enables the oncosis of the human hepatocellular carcinoma cells by down-regulation of the expression of the c-myc and up-regulation of the expression of the p53 in vitro.

  1. C-Myc regulates substrate oxidation patterns during early pressure-overload hypertrophy

    Energy Technology Data Exchange (ETDEWEB)

    Ledee, Dolena R. [Seattle Children' s Research Inst., Seattle, WA (United States); Smith, Lincoln [Seattle Children' s Hospital, Seattle, WA (United States); Kajimoto, Masaki [Seattle Children' s Research Inst., Seattle, WA (United States); Bruce, Margaret [Seattle Children' s Research Inst., Seattle, WA (United States); Isern, Nancy G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Xu, Chun [Seattle Children' s Research Inst., Seattle, WA (United States); Portman, Michael A. [Seattle Children' s Research Inst., Seattle, WA (United States); Olson, Aaron [Seattle Children' s Research Inst., Seattle, WA (United States)

    2013-11-26

    Pressure overload cardiac hypertrophy alters substrate metabolism. Prior work showed that myocardial inactivation of c-Myc (Myc) attenuated hypertrophy and decreased expression of glycolytic genes after aortic constriction. Accordingly, we hypothesize that Myc regulates substrate preferences for the citric acid cycle during pressure overload hypertrophy from transverse aortic constriction (TAC) and that these metabolic changes impact cardiac function and growth. To test this hypothesis, we subjected FVB mice with cardiac specific, inducible Myc inactivation (MycKO-TAC) and non-transgenic littermates (Cont-TAC) to transverse aortic constriction (n=7/group). A separate group underwent sham surgery (Sham, n=5). After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketones and unlabeled glucose and insulin. Western blots were used to evaluate metabolic enzymes. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. Compared to Sham, Cont-TAC had increased free fatty acid fractional contribution with a concurrent decrease in unlabeled (presumably glucose) contribution. Myc inactivation (MycKO-TAC) inhibited these metabolic changes. Hypertrophy in general increased protein levels of PKM2; however this change was not linked to Myc status. Protein post-translation modification by O-GlcNAc was significantly greater in Cont-TAC versus both Sham and MycKO-TAC. In conclusion, Myc regulates substrate utilization during early pressure overload hypertrophy. Our results show that the metabolic switch during hypertrophy is not necessary to maintain cardiac function, but it may be important mechanism to promote cardiomyocyte growth. Myc also regulates protein O-GlcNAcylation during hypertrophy.

  2. c-Myc Transforms Human Mammary Epithelial Cells through Repression of the Wnt Inhibitors DKK1 and SFRP1▿ †

    Science.gov (United States)

    Cowling, Victoria H.; D'Cruz, Celina M.; Chodosh, Lewis A.; Cole, Michael D.

    2007-01-01

    c-myc is frequently amplified in breast cancer; however, the mechanism of myc-induced mammary epithelial cell transformation has not been defined. We show that c-Myc induces a profound morphological transformation in human mammary epithelial cells and anchorage-independent growth. c-Myc suppresses the Wnt inhibitors DKK1 and SFRP1, and derepression of DKK1 or SFRP1 reduces Myc-dependent transforming activity. Myc-dependent repression of DKK1 and SFRP1 is accompanied by Wnt target gene activation and endogenous T-cell factor activity. Myc-induced mouse mammary tumors have repressed SFRP1 and increased expression of Wnt target genes. DKK1 and SFRP1 inhibit the transformed phenotype of breast cancer cell lines, and DKK1 inhibits tumor formation. We propose a positive feedback loop for activation of the c-myc and Wnt pathways in breast cancer. PMID:17485441

  3. Use of a transfected and amplified Drosophila heat shock promoter construction for inducible production of toxic mouse c-myc proteins in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Wurm, F.M.; Gwinn, K.A.; Papoulas, O.; Pallavicini, M.; Kingston, R.E.

    1987-07-24

    After transfection and selection with methotrexate, CHO cell lines were established which contained up to 2000 copies of an expression vector for c-myc protein. The vector contained the Drosophila heat shock protein 70 (hsp70) promoter fused with the coding region of the mouse c-myc gene. Incubation of cells for up to 3 hours at 43/sup 0/C resulted in at least a 100-fold induction of recombinant c-myc mRNA. When cells were shifted back to 37/sup 0/C, within 1 to 4 hours, this RNA was translated into protein to yield about 250 ..mu..g per 10/sup 9/ cells. Cells died a few hours later, suggesting that high concentrations of intracellular c-myc are cytotoxic. 47 refs., 5 figs.

  4. Cloned origin of DNA replication in c-myc gene can function and be transmitted in transgenic mice in an episomal state.

    OpenAIRE

    Sudo, Katsuko; Ogata, Masaaki; Sato, Yoshinari; Iguchi-Ariga, Sanae M. M.; Ariga, Hiroyoshi

    1990-01-01

    The c-myc protein has recently been shown to interact with a region possessing putative origin of DNA replication and enhancer activities located 2 kb upstream of the c-myc gene itself. Transgenic mice were obtained by injecting constructs containing this region, termed pmyc(H-P), into fertilized mouse eggs. The transgenic elements were capable of efficient replication in all mouse tissues examined and were maintained in an episomal state even in highly differentiated cells. Moreover, pmyc(H-...

  5. Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer

    Science.gov (United States)

    2015-10-01

    Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer 3 Annual Progress Report W81XWH-13-1-0162 Using a Novel...Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer Feng Yang, Ph.D. Department of...AWARD NUMBER: W81XWH-13-1-0162 TITLE: Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and

  6. The immunomodulatory benzodiazepine Bz-423 inhibits B-cell proliferation by targeting c-myc protein for rapid and specific degradation.

    Science.gov (United States)

    Sundberg, Thomas B; Ney, Gina M; Subramanian, Chitra; Opipari, Anthony W; Glick, Gary D

    2006-02-01

    Myc proteins regulate cell growth and are oncogenic in many cancers. Although these proteins are validated molecular anticancer targets, new therapies aimed at modulating myc have yet to emerge. A benzodiazepine (Bz-423) that was discovered in efforts to find new drugs for lupus was found recently to have antiproliferative effects on Burkitt's lymphoma cells. We now show that the basis for the antiproliferative effects of Bz-423 is the rapid and specific depletion of c-myc protein, which is coupled to growth-suppressing effects on key regulators of proliferation and cell cycle progression. c-Myc is depleted as a result of signals coupled to Bz-423 binding its molecular target, the oligomycin sensitivity-conferring protein subunit of the mitochondrial F(1)F(o)-ATPase. Bz-423 inhibits F(1)F(o)-ATPase activity, blocking respiratory chain function and generating superoxide, which at growth-inhibiting concentrations triggers proteasomal degradation of c-myc. Bz-423-induced c-myc degradation is independent of glycogen synthase kinase but is substantially blocked by mutation of the phosphosensitive residue threonine 58, which when phosphorylated targets c-myc for ubiquitination and subsequent proteasomal degradation. Collectively, this work describes a new lead compound, with drug-like properties, which regulates c-myc by a novel molecular mechanism that may be therapeutically useful.

  7. Regulation of human ornithine decarboxylase expression following prolonged quiescence: role for the c-Myc/Max protein complex.

    Science.gov (United States)

    Peña, A; Wu, S; Hickok, N J; Soprano, D R; Soprano, K J

    1995-02-01

    WI-38 cells can remain quiescent for long periods of time and still be induced to reenter the cell cycle by the addition of fresh serum. However, the longer these cells remain growth arrested, the more time they require to enter S phase. This prolongation of the prereplicative phase has been localized to a point early in G1, after the induction of "immediate early" G1 genes such as c-fos and c-jun but before maximal expression of "early" G1 genes such as ornithine decarboxylase (ODC). Understanding the molecular basis for ODC mRNA induction can therefore provide information about the molecular events which regulate the progression of cells out of long-term quiescence into G1 and subsequently into DNA synthesis. Studies utilizing electrophoretic mobility shift assays (EMSA) of nuclear extracts from short- and long-term quiescent WI-38 cells identified a region of the human ODC promoter at -491 bp to -474 bp which exhibited a protein binding pattern that correlated with the temporal pattern of ODC mRNA expression. The presence of a CACGTG element within this fragment, studies with antibodies against c-Myc and Max, the use of purified recombinant c-Myc protein in the mobility shift assay, and antisense studies suggest that these proteins can specifically bind this portion of the human ODC promoter in a manner consistent with growth-associated modulation of the expression of ODC and other early G1 genes following prolonged quiescence. These studies suggest a role for the c-Myc/Max protein complex in regulating events involved in the progression of cells out of long-term quiescence into G1 and subsequently into S.

  8. c-myc protein can be substituted for SV40 T antigen in SV40 DNA replication.

    OpenAIRE

    Iguchi-Ariga, Sanae M. M.; Itani, Teru; Yamaguchi, Masamitsu; Ariga, Hiroyoshi

    1987-01-01

    Replicating activity of SV40 origin-containing plasmid was tested in human cells as well as in monkey CosI cells. All the plasmids possessing SV40 ori sequences could replicate, even in the absence of SV40 T antigen, in human HL-60 and Raji cells which are expressing c-myc gene at high level. The copy numbers of the replicated plasmids in these human cells were 1/100 as high as in monkey CosI cells which express SV40 T antigen constitutively. Exactly the same plasmids as the transfected origi...

  9. Critical B-lymphoid cell intrinsic role of endogenous MCL-1 in c-MYC-induced lymphomagenesis

    OpenAIRE

    Grabow, S; Kelly, G L; Delbridge, A R D; Kelly, P N; Bouillet, P; Adams, J M; Strasser, A.

    2016-01-01

    Evasion of apoptosis is critical for tumorigenesis, and sustained survival of nascent neoplastic cells may depend upon the endogenous levels of pro-survival BCL-2 family members. Indeed, previous studies using gene-targeted mice revealed that BCL-XL, but surprisingly not BCL-2, is critical for the development of c-MYC-induced pre-B/B lymphomas. However, it remains unclear whether another pro-survival BCL-2 relative contributes to their development. MCL-1 is an intriguing candidate, because it...

  10. Theabrownin Inhibits Cell Cycle Progression and Tumor Growth of Lung Carcinoma through c-myc-Related Mechanism

    Science.gov (United States)

    Zhou, Li; Wu, Feifei; Jin, Wangdong; Yan, Bo; Chen, Xin; He, Yingfei; Yang, Weiji; Du, Wenlin; Zhang, Qiang; Guo, Yonghua; Yuan, Qiang; Dong, Xiaoqiao; Yu, Wenhua; Zhang, Jin; Xiao, Luwei; Tong, Peijian; Shan, Letian; Efferth, Thomas

    2017-01-01

    Green tea, the fresh leaves of Camellia sinensis, is not only a health-promoting beverage but also a traditional Chinese medicine used for prevention or treatment of cancer, such as lung cancer. Theabrownin (TB) is the main fraction responsible for the medicinal effects of green tea, but whether it possesses anti-cancer effect is unknown yet. This study aimed to determine the in vitro and in vivo anti-lung cancer effect of TB and explore the underlying molecular mechanism, by using A549 cell line and Lewis lung carcinoma-bearing mice. In cellular experiment, MTT assay was performed to evaluate the inhibitory effect and IC50 values of TB, and flow cytometry was conducted to analyze the cell cycle progression affected by TB. In animal experiment, mice body mass, tumor incidence, tumor size and tumor weight were measured, and histopathological analysis on tumor was performed with Transferase dUTP nick-end labeling staining. Real time PCR and western blot assays were adopted to detect the expression of C-MYC associated genes and proteins for mechanism clarification. TB was found to inhibit A549 cell viability in a dose- and time-dependent manner and block A549 cell cycle at G0/G1 phase. Down-regulation of c-myc, cyclin A, cyclin D, cdk2, cdk4, proliferation of cell nuclear antigen and up-regulation of p21, p27, and phosphate and tension homolog in both gene and protein levels were observed with TB treatment. A c-myc-related mechanism was thereby proposed, since c-myc could transcriptionally regulate all other genes in its downstream region for G1/S transitions of cell cycle and proliferation of cancer cells. This is the first report regarding the anti-NSCLC effect and the underlying mechanism of TB on cell cycle progression and proliferation of A549 cells. The in vivo data verified the in vitro result that TB could significantly inhibit the lung cancer growth in mice and induce apoptosis on tumors in a dose-dependent manner. It provides a promising candidate of natural

  11. Involvement of SIRT1 in hypoxic down-regulation of c-Myc and β-catenin and hypoxic preconditioning effect of polyphenols

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Kyung-Soo [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Research Center for Ischemic Tissue regeneration, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Park, Jun-Ik [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Kim, Mi-Ju; Kim, Hak-Bong; Lee, Jae-Won [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Research Center for Ischemic Tissue regeneration, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Dao, Trong Tuan; Oh, Won Keun [BK21 Project Team, College of Pharmacy, Chosun University, Gwangju (Korea, Republic of); Kang, Chi-Dug, E-mail: kcdshbw@pusan.ac.kr [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Kim, Sun-Hee, E-mail: ksh7738@pusan.ac.kr [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Research Center for Ischemic Tissue regeneration, Pusan National University School of Medicine, Yangsan (Korea, Republic of)

    2012-03-01

    SIRT1 has been found to function as a Class III deacetylase that affects the acetylation status of histones and other important cellular nonhistone proteins involved in various cellular pathways including stress responses and apoptosis. In this study, we investigated the role of SIRT1 signaling in the hypoxic down-regulations of c-Myc and β-catenin and hypoxic preconditioning effect of the red wine polyphenols such as piceatannol, myricetin, quercetin and resveratrol. We found that the expression of SIRT1 was significantly increased in hypoxia-exposed or hypoxic preconditioned HepG2 cells, which was closely associated with the up-regulation of HIF-1α and down-regulation of c-Myc and β-catenin expression via deacetylation of these proteins. In addition, blockade of SIRT1 activation using siRNA or amurensin G, a new potent SIRT1 inhibitor, abolished hypoxia-induced HIF-1α expression but increased c-Myc and β-catenin expression. SIRT1 was also found to stabilize HIF-1α protein and destabilize c-Myc, β-catenin and PHD2 under hypoxia. We also found that myricetin, quercetin, piceatannol and resveratrol up-regulated HIF-1α and down-regulated c-Myc, PHD2 and β-catenin expressions via SIRT1 activation, in a manner that mimics hypoxic preconditioning. This study provides new insights of the molecular mechanisms of hypoxic preconditioning and suggests that polyphenolic SIRT1 activators could be used to mimic hypoxic/ischemic preconditioning. -- Graphical abstract: Polyphenols mimicked hypoxic preconditioning by up-regulating HIF-1α and SIRT1 and down-regulating c-Myc, PHD2, and β-catenin. HepG2 cells were pretreated with the indicated doses of myricetin (MYR; A), quercetin (QUR; B), or piceatannol (PIC; C) for 4 h and then exposed to hypoxia for 4 h. Levels of HIF-1α, SIRT1, c-Myc, β-catenin, and PHD2 were determined by western blot analysis. The data are representative of three individual experiments. Highlights: ► SIRT1 expression is increased in hypoxia

  12. BRCA1 and c-Myc associate to transcriptionally repress psoriasin, a DNA damage-inducible gene.

    Science.gov (United States)

    Kennedy, Richard D; Gorski, Julia J; Quinn, Jennifer E; Stewart, Gail E; James, Colin R; Moore, Stephen; Mulligan, Karl; Emberley, Ethan D; Lioe, Tong F; Morrison, Patrick J; Mullan, Paul B; Reid, George; Johnston, Patrick G; Watson, Peter H; Harkin, D Paul

    2005-11-15

    Evidence is accumulating to suggest that some of the diverse functions associated with BRCA1 may relate to its ability to transcriptionally regulate key downstream target genes. Here, we identify S100A7 (psoriasin), S100A8, and S100A9, members of the S100A family of calcium-binding proteins, as novel BRCA1-repressed targets. We show that functional BRCA1 is required for repression of these family members and that a BRCA1 disease-associated mutation abrogates BRCA1-mediated repression of psoriasin. Furthermore, we show that BRCA1 and c-Myc form a complex on the psoriasin promoter and that BRCA1-mediated repression of psoriasin is dependent on functional c-Myc. Finally, we show that psoriasin expression is induced by the topoisomerase IIalpha poison, etoposide, in the absence of functional BRCA1 and increased psoriasin expression enhances cellular sensitivity to this chemotherapeutic agent. Therefore, we identified a novel transcriptional mechanism that is likely to contribute to BRCA1-mediated resistance to etoposide.

  13. Oncogenic K-ras confers SAHA resistance by up-regulating HDAC6 and c-myc expression.

    Science.gov (United States)

    Wang, Qun; Tan, Rong; Zhu, Xin; Zhang, Yi; Tan, Zhiping; Su, Bing; Li, Yu

    2016-03-01

    Histone deacetylase inhibitors (HDIs) represent a new class of anticancer drugs. Suberoylanilide hydroxamic acid (SAHA), the first HDI approved for the treatment of cutaneous T cell lymphoma (CTCL), is currently being tested in clinical trials for other cancers. However, SAHA has been ineffective against solid tumors in many clinical trials. A better understanding of molecular mechanisms of SAHA resistance may provide the basis for improved patient selection and the enhancement of clinical efficacy. Here we demonstrate that oncogenic K-ras contributes to SAHA resistance by upregulating HDAC6 and c-myc expression. We find that the high levels of HDAC6 expression are associated with activated K-ras mutant in colon cancer patients. And expressions of HDAC6 and c-myc are increased in fibroblasts transformed with activated K-ras. Surprisingly, we find that activated K-ras transformed cells are more resistant to SAHA inhibition on cell growth and anchorage-independent colony formation. We show that a K-ras inhibitor sensitizes K-ras mutated lung cancer cells to SAHA induced growth inhibition. We also find that mutant K-ras induces HDAC6 expression by a MAP kinase dependent pathway. Our study suggests that combined treatment with SAHA and K-ras inhibitors may represent an effective strategy to overcome SAHA resistance.

  14. Targeting c-Myc-activated genes with a correlation method: Detection of global changes in large gene expression network dynamics

    Science.gov (United States)

    Remondini, D.; O'Connell, B.; Intrator, N.; Sedivy, J. M.; Neretti, N.; Castellani, G. C.; Cooper, L. N.

    2005-01-01

    This work studies the dynamics of a gene expression time series network. The network, which is obtained from the correlation of gene expressions, exhibits global dynamic properties that emerge after a cell state perturbation. The main features of this network appear to be more robust when compared with those obtained with a network obtained from a linear Markov model. In particular, the network properties strongly depend on the exact time sequence relationships between genes and are destroyed by random temporal data shuffling. We discuss in detail the problem of finding targets of the c-myc protooncogene, which encodes a transcriptional regulator whose inappropriate expression has been correlated with a wide array of malignancies. The data used for network construction are a time series of gene expression, collected by microarray analysis of a rat fibroblast cell line expressing a conditional Myc-estrogen receptor oncoprotein. We show that the correlation-based model can establish a clear relationship between network structure and the cascade of c-myc-activated genes. PMID:15867157

  15. Critical Role of c-Myc in Acute Myeloid Leukemia Involving Direct Regulation of miR-26a and Histone Methyltransferase EZH2

    Science.gov (United States)

    Salvatori, Beatrice; Iosue, Ilaria; Djodji Damas, Nkerorema; Mangiavacchi, Arianna; Chiaretti, Sabina; Messina, Monica; Padula, Fabrizio; Guarini, Anna; Bozzoni, Irene; Fazi, Francesco; Fatica, Alessandro

    2011-01-01

    Increased expression or aberrant activation of c-Myc plays an important role in leukemogenesis. Here, we show that in acute myeloid leukemia (AML), c-Myc directly controls the expression of EZH2, a component of the Polycomb repressive complex 2, and miR-26a. miR-26a is downregulated in primary blasts from AML patients and, during myeloid differentiation of AML cells, is induced together with a decrease in c-Myc and Ezh2 levels. Previously, EZH2 was shown to be regulated by miR-26a at the translational levels in lymphomas. However, we demonstrate that in AML, the variation of EZH2 mainly depends on c-Myc transcriptional control. We also show that enforced expression of miR-26a in AML cells is able to inhibit cell cycle progression by downregulating cyclin E2 expression. In addition, increased levels of miR-26a potentiate the antiproliferative effects of 1,25-dihydroxyvitamin D3 (VitD) and stimulate myeloid differentiation. Our results identify new molecular targets of c-Myc in AML and highlight miR-26a attractiveness as a therapeutic target in leukemia. PMID:21901171

  16. Upregulation of c-MYC in cis through a Large Chromatin Loop Linked to a Cancer Risk-Associated Single-Nucleotide Polymorphism in Colorectal Cancer Cells▿

    Science.gov (United States)

    Wright, Jason B.; Brown, Seth J.; Cole, Michael D.

    2010-01-01

    Genome-wide association studies have mapped many single-nucleotide polymorphisms (SNPs) that are linked to cancer risk, but the mechanism by which most SNPs promote cancer remains undefined. The rs6983267 SNP at 8q24 has been associated with many cancers, yet the SNP falls 335 kb from the nearest gene, c-MYC. We show that the beta-catenin-TCF4 transcription factor complex binds preferentially to the cancer risk-associated rs6983267(G) allele in colon cancer cells. We also show that the rs6983267 SNP has enhancer-related histone marks and can form a 335-kb chromatin loop to interact with the c-MYC promoter. Finally, we show that the SNP has no effect on the efficiency of chromatin looping to the c-MYC promoter but that the cancer risk-associated SNP enhances the expression of the linked c-MYC allele. Thus, cancer risk is a direct consequence of elevated c-MYC expression from increased distal enhancer activity and not from reorganization/creation of the large chromatin loop. The findings of these studies support a mechanism for intergenic SNPs that can promote cancer through the regulation of distal genes by utilizing preexisting large chromatin loops. PMID:20065031

  17. Local Delivery of C-myc Antisense Oligodeoxynucleotide by Gelatin Coated Platinium-Iridium Stent to Prevent Restenosis in a Normal Rabbit Carotid Artery

    Institute of Scientific and Technical Information of China (English)

    Zhang Xinxia; Wei Wenbin; Duan Wen; Xu Xiangguang; Hu Xuesong

    2005-01-01

    Objectives To investigate the feasibility and effect of local deliveryof c-myc antisense oligodeoxynucleotide (ASODN) by gelatin coated Platinium-Iridium stent to prevent restenosis in a normal rabbit carotid artery. Methods Gelatin coated Platinium-Iridium stent were implanted in the right carotid arteries of 32 rabbits under vision. Animals were randomized to the control group and the treated group receiving c-myc ASODN (n=16 respectively).7,14,30,90 days following the stenting procedure,morphometry for caculation of neointimal area and mean neointimal thickness were performed.The expression of c-myc protein was detected by immunohistochemical methods. Results 32 stents were successfully implanted into the right carotid arteries in 32 animals. Morphometric analysis showed that neointimal area and mean neointimal thickness siginificantly increased continuously up to 12 weeks after stent implantation,and at each time point ,neointimal area and mean neointimal thickness were siginificantly smaller in the treated group than control group. (P<0.001 ,respectively).c-myc protein expression was weak positive or negative in treated group and positive in control group. Conclusions Gelatin coated Platinium-Iridium stent mediated local delivery of c-myc ASODN is feasibility , and it can inhibit neointimal hyperplasia to prevent restenosis in a normal rabbit carotid artery.

  18. Expressions of beta-catenin, APC Protein, C-myc and Cyclin D1 in Ovarian Epithelial Tumor and Their Implication

    Institute of Scientific and Technical Information of China (English)

    LIN Xiao; LI Yu; MI Can

    2007-01-01

    Objective: To investigate the expressions of beta-catenin, protein APC (adenomatous polyposis coli protein), c-myc and cyclin D1 and their implication in ovarian epithelial tumor. Methods: Immunohistochemical staining with SP method was conducted to identify the expressions of beta-catenin, APC protein, c-myc and cyclin D1 in ovarian epithelial tumor in 48 cases. Results: The abnormal expression rate of beta-catenin in malignant and borderline ovarian epithelial tumors was higher than that in benign epithelial tumors (P<0.01). The expression rates of c-myc and cyclin-D1 in ovarian malignant and borderline epithelial tumors were higher than those in benign epithelial tumors too(P<0.05). The prevalence of APC protein positive expression in benign epithelial tumors were significantly greater than that in malignant epithelial tumors (P<0.05). A significant negative correlation was found between beta-catenin and APC protein in ovarian epithelial tumors; while a significant positive correlation was found between beta-catenin, c-myc and cyclin-D1 in ovarian epithelial tumor (P<0.05). Conclusion: The abnormal expressions of Beta-catenin, APC protein, c-myc and cyclin-D1 might be used to indicate the malignance transform of ovarian epithelial tumors.

  19. c-Myc-miR-29c-REV3L signalling pathway drives the acquisition of temozolomide resistance in glioblastoma.

    Science.gov (United States)

    Luo, Hui; Chen, Zhengxin; Wang, Shuai; Zhang, Rui; Qiu, Wenjin; Zhao, Lin; Peng, Chenghao; Xu, Ran; Chen, Wanghao; Wang, Hong-Wei; Chen, Yuanyuan; Yang, Jingmin; Zhang, Xiaotian; Zhang, Shuyu; Chen, Dan; Wu, Wenting; Zhao, Chunsheng; Cheng, Gang; Jiang, Tao; Lu, Daru; You, Yongping; Liu, Ning; Wang, Huibo

    2015-12-01

    Resistance to temozolomide poses a major clinical challenge in glioblastoma multiforme treatment, and the mechanisms underlying the development of temozolomide resistance remain poorly understood. Enhanced DNA repair and mutagenesis can allow tumour cells to survive, contributing to resistance and tumour recurrence. Here, using recurrent temozolomide-refractory glioblastoma specimens, temozolomide-resistant cells, and resistant-xenograft models, we report that loss of miR-29c via c-Myc drives the acquisition of temozolomide resistance through enhancement of REV3L-mediated DNA repair and mutagenesis in glioblastoma. Importantly, disruption of c-Myc/miR-29c/REV3L signalling may have dual anticancer effects, sensitizing the resistant tumours to therapy as well as preventing the emergence of acquired temozolomide resistance. Our findings suggest a rationale for targeting the c-Myc/miR-29c/REV3L signalling pathway as a promising therapeutic approach for glioblastoma, even in recurrent, treatment-refractory settings.

  20. The role of micro RNAs let7c, 100 and 218 expression and their target RAS, C-MYC, BUB1, RB, SMARCA5, LAMB3 and Ki-67 in prostate cancer

    Directory of Open Access Journals (Sweden)

    Sabrina T. Reis

    2013-05-01

    Full Text Available OBJECTIVE: The aim of this study is to verify the expression of proteins that are controlled by miR-let7c, 100 and 218 using immunohistochemistry in tissue microarray representative of localized and metastasized the lymph nodes and bone prostate cancer. METHODS: To verify the expression of proteins that are controlled by miR-let7c (C-MYC, BUB1, RAS 100 (SMARCA5, RB and 218 (LAMB3 and cell proliferation (Ki-67 we used immunohistochemistry and computerized image system ImageJ MacBiophotonics in three tissue microarrays representative of localized prostate cancer and lymph node and bone metastases. miRNA expression was evaluated by qRT-PCR using 60 paraffin blocks to construct the tissue microarray representative of localized disease. RESULTS: RAS expression was increased in localized prostate cancer and bone metastases compared to the lymph nodes (p=0.017. RB showed an increase in expression from localized prostate cancer to lymph node and bone metastasis (p=0.036. LAMB3 was highly expressed in localized and lymph node metastases (p<0.001. Cell proliferation evaluated by Ki-67 showed an increase from localized prostate cancer to metastases (p<0.001. We did not found any relationship between C-MYC (p=0.253, BUB1 (p=0.649 and SMARCA5 (p=0.315 protein expression with prognosis or tumor behavior. CONCLUSION: We found that the expression of RAS, RB, LAMB3 and Ki-67 changed in the different stages of prostate cancer. Furthermore, we confirmed the overexpression of the miRNAs let7c, 100 and 218 in localized prostate cancer but failed to show the control of protein expression by the putative controller miRNAs using immunohistochemistry.

  1. Investigating actinomycin D binding to G-quadruplex, i-motif and double-stranded DNA in 27-nt segment of c-MYC gene promoter.

    Science.gov (United States)

    Niknezhad, Zhila; Hassani, Leila; Norouzi, Davood

    2016-01-01

    c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy. Around 90% of c-MYC transcription is controlled by NHE III1, whose 27-nt purine-rich strand has the ability to form G-quadruplex structure. In this investigation, interaction of ActD with 27-nt G-rich strand (G/c-MYC) and its equimolar mixture with the complementary sequence, (GC/c-MYC) as well as related C-rich oligonucleotide (C/c-MYC) was evaluated. Molecular dynamic simulations showed that phenoxazine and lactone rings of ActD come close to the outer G-tetrad nucleotides indicating that ActD binds through end-stacking to the quadruplex DNA. RMSD and RMSF revealed that fluctuation of the quadruplex DNA increases upon interaction with the drug. The results of spectrophotometry and spectrofluorometry indicated that ActD most probably binds to the c-MYC quadruplex and duplex DNA via end-stacking and intercalation, respectively and polarity of ActD environment decreases due to the interaction. It was also found that binding of ActD to the GC-rich DNA is stronger than the two other forms of DNA. Circular dichroism results showed that the type of the three forms of DNA structures doesn't change, but their compactness alters due to their interaction with ActD. Finally, it can be concluded that ActD binds differently to double stranded DNA, quadruplex DNA and i-motif.

  2. Long-term cultivation of in vitro Apis mellifera cells by gene transfer of human c-myc proto-oncogene.

    Science.gov (United States)

    Kitagishi, Yasuko; Okumura, Naoko; Yoshida, Hitomi; Nishimura, Yuri; Takahashi, Jun-ichi; Matsuda, Satoru

    2011-08-01

    Establishment of cell lines representative of honeybee character would greatly assist in their analysis. Here, we show that immortalized cell line, designated as MYN9, has been generated from honeybee embryo by the gene transfer of human c-myc proto-oncogene. The morphology of the cell is characteristic of embryonic stem cell, although the cell is stable and does not spontaneously differentiate. Polymerase chain reaction analyses show that the cell is originated from authentic honeybee cell. It is proposed that the integration of human c-myc gene into honeybee precursor populations results in the establishment of stable cell line suitable for cellular and molecular studies.

  3. Identification of functional networks of estrogen- and c-Myc-responsive genes and their relationship to response to tamoxifen therapy in breast cancer.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Musgrove

    Full Text Available BACKGROUND: Estrogen is a pivotal regulator of cell proliferation in the normal breast and breast cancer. Endocrine therapies targeting the estrogen receptor are effective in breast cancer, but their success is limited by intrinsic and acquired resistance. METHODOLOGY/PRINCIPAL FINDINGS: With the goal of gaining mechanistic insights into estrogen action and endocrine resistance, we classified estrogen-regulated genes by function, and determined the relationship between functionally-related genesets and the response to tamoxifen in breast cancer patients. Estrogen-responsive genes were identified by transcript profiling of MCF-7 breast cancer cells. Pathway analysis based on functional annotation of these estrogen-regulated genes identified gene signatures with known or predicted roles in cell cycle control, cell growth (i.e. ribosome biogenesis and protein synthesis, cell death/survival signaling and transcriptional regulation. Since inducible expression of c-Myc in antiestrogen-arrested cells can recapitulate many of the effects of estrogen on molecular endpoints related to cell cycle progression, the estrogen-regulated genes that were also targets of c-Myc were identified using cells inducibly expressing c-Myc. Selected genes classified as estrogen and c-Myc targets displayed similar levels of regulation by estrogen and c-Myc and were not estrogen-regulated in the presence of siMyc. Genes regulated by c-Myc accounted for 50% of all acutely estrogen-regulated genes but comprised 85% (110/129 genes in the cell growth signature. siRNA-mediated inhibition of c-Myc induction impaired estrogen regulation of ribosome biogenesis and protein synthesis, consistent with the prediction that estrogen regulates cell growth principally via c-Myc. The 'cell cycle', 'cell growth' and 'cell death' gene signatures each identified patients with an attenuated response in a cohort of 246 tamoxifen-treated patients. In multivariate analysis the cell death signature

  4. The reducing agent Dithiothreitol (DTT) increases expression of c-myc and c- fos protooncogenes in human cells

    DEFF Research Database (Denmark)

    Skouv, J.; Sørensen, Ilona Kryspin; Frandsen, H.

    1995-01-01

    The objective of the present study was to assess the possible tumour promoting activity of the food mutagen 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP), by studying its influence on the expression of three genes considered to be of relevance in the tumour promotion step....... However, when cells were treated with DTT alone, the expression of c-fos and c-myc was also transiently induced. We therefore conclude that DTT, and not N-OH-PhIP, induced oncogene expression. Induction of both c-fos and c-mye expression by a reducing agent, DTT, which is frequently used in in vitro...

  5. Nucleolus disassembly in mitosis and apoptosis: dynamic redistribution of phosphorylated-c-Myc, fibrillarin and Ki-67

    Directory of Open Access Journals (Sweden)

    C Soldani

    2009-06-01

    Full Text Available The nucleolus may undergo disassembly either reversibly during mitosis, or irreversibly in apoptosis, thus allowing the redistribution of the nucleolar proteins.We investigated here by immunocytochemistry the fate of three representative proteins, namely phosphorylated c-Myc, fibrillarin and Ki-67, and found that they behave independently in both processes: they relocate in distinct compartments during mitosis, whereas during apoptosis they may either be cleaved (Ki-67 or be extruded into the cytoplasm with a different kinetics and following an ordered, non chaotic program. The separation of these nucleolar proteins which occurs in early apoptotic nuclei continues also in the cytoplasm, and culminates in the final formation of apoptotic blebs containing different nucleolar proteins: this evidence confirms that the apoptotic bodies may be variable in size, content and surface reactivity, and include heterogeneous aggregates of nuclear proteins and/or nucleic acids.

  6. Effects of matrine on the growth inhibition, c-myc and hTERT protein expression in human adenocarcinoma lung cancer cell line A549

    Directory of Open Access Journals (Sweden)

    Qiong CHEN

    2008-08-01

    Full Text Available Background and objective It was reported that telomerase was associated with the oncogenesis and progression of cancer, and to be the common targets of cancer therapy. The mechanism of matrine on lung cancer in vitro is not clear. We studied the effect of matrine on growth of human lung adenocarcinoma A549 cells and the mechanism related with telomerase. Methods MTT was used for measuring A549 cells viability, Hoechst 33342-propidium iodide fluorescent staining for observing apoptotic cells, flow cytometry (FCM for analyzing cell cycle and apoptosis, and immunocytochemistry for measuring the protein expressions of c-myc and hTERT in A549 cells. Results Matrine inhibited the proliferation of A549 cells with a time-dose-dependent manner (P<0.05. Hoechst 33342-propidium iodide staining showed apoptotic cells with chromatin condensation and fragmentation of nuclei. FCM analysis indicated elevating rate of cells in G0/G1 phase, lowering rate of that in S phase and the highering apoptotic rate. The levels of c-myc and hTERT protein expression in the matrine group was lower than that in the control group (P<0.05, and AOD of c-myc showed positive correlation with AOD of hTERT (r=0.633, P<0.01 Conclusion The inhibitory effect of matrine on A549 cells may be related to the lower expression of c-myc and hTERT.

  7. The use of FISH-comet to detect c-Myc and TP 53 damage in extended-term lymphocyte cultures treated with terbuthylazine and carbofuran.

    Science.gov (United States)

    Mladinic, Marin; Zeljezic, Davor; Shaposhnikov, Sergey A; Collins, Andrew R

    2012-05-20

    Terbuthylazine and carbofuran are suspected to cause non-Hodgkin's lymphoma and lung cancer. We evaluated the effects of prolonged exposure to low concentrations on primary DNA damage by comet assay, and on the structural integrity of c-Myc and TP 53 genes by FISH-comet. Another novelty in studying these pesticides' genotoxicity is the use of 14-day extended-term human lymphocyte cultures. Concentrations corresponded to values of ADI and OEL: for terbuthylazine 0.58 ng/ml and 8 ng/ml; for carbofuran 8 ng/ml and 21.6 ng/ml, respectively. A possible effect of metabolic activation (S9) was also considered. Carbofuran treatment induced a significant migration of DNA into the tail in a concentration-dependent manner, while for terbuthylazine the effect was significant only at the higher concentration. Terbuthylazine caused migration of both c-Myc signals into the comet tail. A significant occurrence of TP 53 signals in the tail was observed at 8 ng/ml. Prolonged carbofuran treatment significantly elevated the migration of a single c-Myc signal into the tail in a concentration-dependent manner. With S9, distribution of signals shifted toward increased presence of both signals in tail. Our results showed impaired structural integrity of c-Myc and TP 53 due to prolonged exposure to terbuthylazine and carbofuran.

  8. Effect of Neem Leaf Extract (Azadirachta indica on c-MycOncogene Expression in 4T1 Breast Cancer Cells of BALB/c Mice

    Directory of Open Access Journals (Sweden)

    Chong Pei Pei

    2012-01-01

    Full Text Available Objective: Breast cancer is the most common cause of cancer-related deaths in women both worldwide and in Malaysia. Azadirachta indica (A. Juss, commonly known as neem, is one of the most versatile medicinal plants that has gained worldwide prominence due to its medicinal properties. However, the anticancer effect of ethanolic neem leaf extract against breast cancer has not been documented. The purpose of the present study is to investigate the effect of neem leaf extract on c-Myc oncogene expression in 4T1 breast cancer BALB/c mice.Materials and Methods: In this experimental study, A total of 48 female BALB/c mice were divided randomly into four groups of 12 mice per group: i.cancer control (CC treated with 0.5% Tween 20 in PBS, ii. 0.5 μg/mL tamoxifen citrate (CT, iii. 250 mg/kg neem leaf extract (C250, and iv. 500 mg/kg neem leaf extract (C500. In situ reverse transcription polymerase chain reaction (in situ RT-PCR was applied to evaluate suppression of c-Myc oncogene expression in breast cancer tissue.Results: The C500 group showed significant (p<0.05 suppression of c-Myc oncogene expression compared to the CC group.Conclusion: c-Myc was found to be down regulated under the effect of 500 mg/kg ethanolicneem leaf extract.

  9. Function of apoptosis and expression of the proteins Bcl-2, p53 and C-myc in the development of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    An Gao Xu; Shao Guang Li; Ji Hong Liu; Ai Hua Gan

    2001-01-01

    @@INTRODUCTION In China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer .

  10. THE HEPARIN-BINDING DOMAIN AND V REGION OF FIBRONECTIN REGULATE APOPTOSIS BY SUPPRESSION OF P53 AND C-MYC IN HUMAN PRIMARY CELLS

    Science.gov (United States)

    In apoptosis the tumor suppressor p53 and oncogene c-myc, are usually upregulated. However, we report here an alternate pathway of regulation that is triggered by inflammatory-associated matrix fragments of fibronectin (FN) and leads to apoptosis. It is mediated by transcriptio...

  11. The inhibition effects of the c-myc targeting CRISPR/Cas9 adenovirus system on hepatoma cells%靶向 c-myc 基因的 CRISPR/Cas9腺病毒系统对肝癌的抑制作用

    Institute of Scientific and Technical Information of China (English)

    连竹生; 梁鑫; 金桂花; 吴领知; 韩苏夏

    2016-01-01

    目的:设计、构建并包装靶向 c-myc 基因的 CRISPR/Cas9腺病毒;评估靶向 c-myc 基因的 CRISPR/Cas9腺病毒系统对肝癌的抑制作用。方法:采用生物信息学网站设计靶向 c-myc 基因的 gRNA,以 GFP 作为对照设计GFP gRNA;通过 T7E1筛选出编辑效率高的 gRNA 并将筛选的 gRNA 构建 CRISPR/Cas9腺病毒载体并包装腺病毒,通过分析细胞增殖、周期和凋亡及迁移能力的变化来评估靶向 c-myc 基因的 CRISPR/Cas9腺病毒系统对肝癌的抑制作用。结果:成功设计、构建并包装靶向 c-myc 基因的 CRISPR/Cas9腺病毒;靶向 c-myc 基因的 CRISPR/Cas9腺病毒系统能够显著抑制 Hepa1-6细胞的增殖和迁移、阻滞细胞周期进程,但对细胞凋亡无影响。结论:靶向 c-myc 基因的 CRISPR/Cas9腺病毒系统可在细胞水平明显抑制肝癌细胞的生长。%Aim:To design,construct and package the CRISPR/Cas9 adenovirus system for targeting the mouse c-myc gene;To evaluate the inhibition efficiency of the constructed adenovirus system on c-myc gene in hepatoma cells.Methods:We designed gRNAs for targeting the mouse c-myc gcontrolene and used another gene (gRNAs for GFP)as control based on bioinformatics website.The editing efficiencies of these gRNAs were determined by T7E1 cleavage.The gRNAs with higher editing efficiency were se-lected and packed into adenovirus for the following experiments.Firstly,Hepa 1-6 cells were infected with the constructed adenovirus,then cell proliferation,cell cycle,cell apoptosis and migration assays were detected to de the inhibition efficiency of the adenovirus on hepatoma cells.Statistical analyses were performed with SPSS(version 18.0)and t-test,P <0.05 was considered statistically significant.Re-sults:The CRISPR/Cas9 adenovirus system targeting the mouse c-myc gene was successfully designed constructed and packaged.Compared with the control group,the experiment groups (with CRISPR/Cas9

  12. c-Myc quadruplex-forming sequence Pu-27 induces extensive damage in both telomeric and nontelomeric regions of DNA.

    Science.gov (United States)

    Islam, Md Ashraful; Thomas, Shelia D; Murty, Vundavalli V; Sedoris, Kara J; Miller, Donald M

    2014-03-21

    Quadruplex-forming DNA sequences are present throughout the eukaryotic genome, including in telomeric DNA. We have shown that the c-Myc promoter quadruplex-forming sequence Pu-27 selectively kills transformed cells (Sedoris, K. C., Thomas, S. D., Clarkson, C. R., Muench, D., Islam, A., Singh, R., and Miller, D. M. (2012) Genomic c-Myc quadruplex DNA selectively kills leukemia. Mol. Cancer Ther. 11, 66-76). In this study, we show that Pu-27 induces profound DNA damage, resulting in striking chromosomal abnormalities in the form of chromatid or chromosomal breaks, radial formation, and telomeric DNA loss, which induces γ-H2AX in U937 cells. Pu-27 down-regulates telomeric shelterin proteins, DNA damage response mediators (RAD17 and RAD50), double-stranded break repair molecule 53BP1, G2 checkpoint regulators (CHK1 and CHK2), and anti-apoptosis gene survivin. Interestingly, there are no changes of DNA repair molecules H2AX, BRCA1, and the telomere maintenance gene, hTERT. ΔB-U937, where U937 cells stably transfected with deleted basic domain of TRF2 is partially sensitive to Pu-27 but exhibits no changes in expression of shelterin proteins. However, there is an up-regulation of CHK1, CHK2, H2AX, BRCA1, and survivin. Telomere dysfunction-induced foci assay revealed co-association of TRF1with γ-H2AX in ATM deficient cells, which are differentially sensitive to Pu-27 than ATM proficient cells. Alt (alternating lengthening of telomere) cells are relatively resistant to Pu-27, but there are no significant changes of telomerase activity in both Alt and non-Alt cells. Lastly, we show that this Pu-27-mediated sensitivity is p53-independent. The data therefore support two conclusions. First, Pu-27 induces DNA damage within both telomeric and nontelomeric regions of the genome. Second, Pu-27-mediated telomeric damage is due, at least in part, to compromise of the telomeric shelterin protein complex.

  13. Pokemon、c-myc在结直肠癌中的表达及意义%EXPRESSION AND CLINICAL SIGNIFICANCE OF POKEMON AND C-MYC IN COLORECTAL CANCER

    Institute of Scientific and Technical Information of China (English)

    刘叔敏; 范玉磊; 梁婷婷; 孙影

    2014-01-01

    目的:探讨结直肠癌组织Pokemon和c-myc蛋白表达的变化和意义。方法:SP免疫组化法检测60例结直肠癌组织和癌旁正常组织Pokemon和c-myc蛋白的表达情况。结果:结直肠癌组织Pokemon和c-myc蛋白的阳性表达率均明显高于正常组织(P<0.01);结直肠癌组织Pokemon和c-myc蛋白的阳性表达与分化程度、Dukes分期和淋巴结转移有关(P<0.01,P<0.05);结直肠癌组织中,Pokemon和c-myc蛋白的表达呈显著正相关(r=0.615,P<0.05)。结论:Pokemon和c-myc对结直肠癌的诊断和预后评判具有一定的价值。%Objective: To investigate the expression and clinical significance of Pokemon and c-myc in human colorectal cancer.Methods: SP immunohistochemical staining was used to detect the expression of Pokemon and c-myc in 60 cases colorectal cancer and matched para-carcinoma tissues.Results:The positive expression rate of Pokemon and c-myc in colorectal cancer were obviously higher than that in normal tissue (P<0.01). In colorectal cancer, the positive expression of Pokemon and c-myc were related with differentiation degree, Dukes stage and lymph node metastasis (P<0.01,P<0.05). The positive expression of Pokemon in colorectal cancer was positively correlated with c-myc expression (r=0.615,P<0.05). Conclusions: Pokemon and c-myc have certain value for diagnosing and prognosis of colorectal cancer.

  14. The function of apoptosis and protein expression of bcl-2, p53 and C-myc inthe development of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    An Gao Xu; Shao Guang Li; Ji Hong Liu; Ai Hua Gan

    2000-01-01

    AIM To understand the rule and possible function of apoptosis and protein expression of bcl-2, p53 and C-myc in chronic gastritis, gastric ulcer, non-classic proliferation of gastric mucosa and gastric cancer.METHODS Apoptosis was detected by using in situ terminal labelling (TUNEL). The protein expression ofbcl-2, p53 and C-myc was detected by immunohistochemical method.RESULTS The indexes of apoptosis in chronic active gastritis, gastric ulcer, mild and severe non-classicproliferation of gastric mucosa, early and progressive gastric cancer were 16.8%±12.3%, 24.1%±20.0%,19.3%±16.4%, 15.7%±15.2%, 10.1%±9.1% and 6.3%±6.0%, respectively. The index of progressivegastric cancer was lower than that of early gastric cancer and non-classic proliferation of gastric mucosa(P<0.05). The positive rate of bcl-2 protein was 9.4%, 27.6%, 52.9%, 75.0%, 83.3% and 46.7%,respectively. The positive rate of bcl-2 of early gastric cancer was higher than that of progressive gastriccancer. The positive rates of p53 protein of severe non-classic proliferation, early and progressive gastriccancer were 25.0%, 33.3% and 63.3%, respectively. The positive rate of p53 of progressive gastric cancerwas higher than that of early gastric cancer and non-classic proliferation (P<0.05). In Lauren types, theindex of apoptosis, protein expression rates of bcl-2, p53 and C-myc of intestinal type were 8.3%±7.2%,38.9%, 77.7% and 56.6%, while that of diffuse type were 5.1%±4.9%, 58.3%, 50.0% and 8.3%,respectively. All markers had statistical difference between two types (P<0.05).CONCLUSION Apoptosis was inhibited stepwise in the development of non-classic proliferation of gastricmucosa to early gastric cancer and then to progressive gastric cancer. The high expression of bcl-2, p53 andC-myc was related to the development of gastric cancer, bcl-2 might play an important role in early gastriccancer while p53 and C-myc act mostly in middle and late stage gastric cancer. The Lauren typing of

  15. Assessment of the effect of betaine on p16 and c-myc DNA methylation and mRNA expression in a chemical induced rat liver cancer model

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    Ling Wen-hua

    2009-07-01

    Full Text Available Abstract Background The development and progression of liver cancer may involve abnormal changes in DNA methylation, which lead to the activation of certain proto-oncogenes, such as c-myc, as well as the inactivation of certain tumor suppressors, such as p16. Betaine, as an active methyl-donor, maintains normal DNA methylation patterns. However, there are few investigations on the protective effect of betaine in hepatocarcinogenesis. Methods Four groups of rats were given diethylinitrosamine (DEN and fed with AIN-93G diets supplemented with 0, 10, 20 or 40 g betaine/kg (model, 1%, 2%, and 4% betaine, respectively, while the control group, received no DEN, fed with AIN-93G diet. Eight or 15 weeks later, the expression of p16 and c-myc mRNA was examined by Real-time PCR (Q-PCR. The DNA methylation status within the p16 and c-myc promoter was analyzed using methylation-specific PCR. Results Compared with the model group, numbers and areas of glutathione S-transferase placental form (GST-p-positive foci were decreased in the livers of the rats treated with betaine (P . Although the frequency of p16 promoter methylation in livers of the four DEN-fed groups appeared to increase, there is no difference among these groups after 8 or 15 weeks (P > 0.05. Betaine supplementation attenuated the down-regulation of p16 and inhibited the up-regulation of c-myc induced by DEN in a dose-dependent manner (P P . Finally, enhanced antioxidative capacity (T-AOC was observed in both the 2% and 4% betaine groups. Conclusion Our data suggest that betaine attenuates DEN-induced damage in rat liver and reverses DEN-induced changes in mRNA levels.

  16. Cytotoxic effect of γ-sitosterol from Kejibeling (Strobilanthes crispus and its mechanism of action towards c-myc gene expression and apoptotic pathway

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    Susi Endrini

    2015-01-01

    Full Text Available Background: This study aimed to analyze the cytotoxicity effect of γ-sitosterol isolated from “Kejibeling” (Strobilanthes crispus, a medicinal plant, on several cancer cell lines. The mechanisms of the effects were studied through the expression of cancer-caused gene, c-myc and apoptotic pathways.Methods: This in vitro study was done using human colon cancer cell lines (Caco-2, liver cancer cell lines (HepG2, hormone-dependent breast cancer cell lines (MCF-7 and the normal liver cell lines (Chang Liver. The cytotoxic effect was measured through MTT assay and the potential cytotoxic value was calculated by determining the toxic concentration which may kill up to 50% of the total cell used (IC50. Meanwhile, the cytotoxic mechanism was studied by determining the effect of adding γ-sitosterol to the c-myc gene expression by reverse transciptase-polymerase chain reaction (RT-PCR. The effect of γ-sitosterol through apoptotic pathway was studied by using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay.Results: γ-sitosterol was cytotoxic against Caco-2, HepG2, and MCF-7 with IC50-values of 8.3, 21.8, and 28.8 μg/mL, respectively. There were no IC50-values obtained from this compound against Chang Liver cell line. This compound induced apotosis on Caco-2 and HepG2 cell lines and suppressed the c-myc genes expression in both cells.Conclusion: γ-sitosterol was cytotoxic against colon and liver cancer cell lines and the effect was mediated by down-regulation of c-myc expression and induction of the apoptotic pathways.

  17. Oxidative damage, pro-inflammatory cytokines, TGF-α and c-myc in chronic HCV-related hepatitis and cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Fabio Farinati; Romilda Cardin; Marina Bortolami; Maria Guido; Massimo Rugge

    2006-01-01

    AIM: To assess whether a correlation exists between oxidative DNA damage occurring in chronic HCV-relatecl hepatitis and expression levels of pro-inflammatory cytokines, TGF-α and c-myc.METHODS: The series included 37 patients with chronic active HCV-related hepatitis and 11 with HCV-related compensated cirrhosis. Eight-hydroxydeoxyguanosine in liver biopsies was quantified using an electrochemical detector. The mRNA expression of TNF-α, IL-1β, TGF-αand c-myc in liver specimens was detected by semiquantitative comparative RT-PCR.RESULTS: TNF-α levels were significantly higher in hepatitis patients than in cirrhosis patients (P=0.05).IL-1β was higher in cirrhosis patients (P=0.05). A significant correlation was found between TNF-α and staging (P=0.05) and between IL-1β levels and grading (P= 0.04). c-myc showed a significantly higher expression in cirrhosis patients (P=0.001). Eight-hydroxydeoxyguanosine levels were significantly higher in cirrhosis patients (P=0.05) and in HCV genotype 1. (P=0.03).Considering all patients, 8-hydroxydeoxyguanosine levels were found to be correlated with genotype (P=0.04)and grading (P=0.007). Also multiple logistic regression analysis demonstrated a significant correlation among the number of DNA adducts, TNF-α expression and HCV genotype (P= 0.02).CONCLUSION: In chronic HCV-related liver damage, oxidative DNA damage correlates with HCV genotype, grading and TNF-α levels. As HCV-related liver damage progresses, TNF-α levels drop while IL-1β and c-myc levels increase, which may be relevant to liver carcinogenesis.

  18. c-myc but not Hif-1α-dependent downregulation of VEGF influences the proliferation and differentiation of HL-60 cells induced by ATRA.

    Science.gov (United States)

    Song, Guanhua; Li, Yanmei; Zhang, Zhiyong; Ren, Xia; Li, Hongjiang; Zhang, Wen; Wei, Ruoying; Pan, Sufei; Shi, Lulu; Bi, Kehong; Jiang, Guosheng

    2013-06-01

    Vascular endothelial growth factor (VEGF) plays an important role in solid tumor growth, progression and metastasis as well as in the proliferation and differentiation of hematological malignancies. However, the molecular mechanism that modulates VEGF expression and secretion in leukemia cells has not yet to be elucidated. The purpose of the present study was to investigate the role of the signal pathway in modulating the expression of VEGF in HL-60 cells. Specific siRNAs targeting VEGF were transfected into HL-60 cells and the VEGF expression was measured with reverse transcription-polymerase chain reaction (RT-PCR) and western blot assay. The cell proliferation of HL-60 cells was detected by the cell counting kit-8 (CCK-8) assay and the differentiation of HL-60 cells induced by all-trans-retinoic acid (ATRA) was detected by the RT-PCR assay and flow cytometry assay for CD11b. The upstream transcription factors that were related to VEGF expression such as P53, SP-1, c-jun, VHL, cox-2, c-myc and stat3 were detected by RT-PCR assay. In addition, the chromatin immunoprecipitation (ChIP) assay was used to reveal the role of c-myc by binding the target gene VEGF. The results demonstrated the hypoxia-inducible factor 1α-related signaling pathway, not the same as in solid tumors, might not play a key role in modulating VEGF expression. c-myc contributes to the modulation of VEGF expression by targeting the promoter of VEGF, which was indicated by the ChIP assay. In conclusion, our data demonstrate that VEGF plays an important role in the differentiation and proliferation of HL-60 cells; c-myc-dependent downregulation of VEGF induced by ATRA contributes to the differentiation of HL-60 cells.

  19. HSPH1 inhibition downregulates Bcl-6 and c-Myc and hampers the growth of human aggressive B-cell non-Hodgkin lymphoma.

    Science.gov (United States)

    Zappasodi, Roberta; Ruggiero, Giusi; Guarnotta, Carla; Tortoreto, Monica; Tringali, Cristina; Cavanè, Alessandra; Cabras, Antonello D; Castagnoli, Lorenzo; Venerando, Bruno; Zaffaroni, Nadia; Gianni, Alessandro M; De Braud, Filippo; Tripodo, Claudio; Pupa, Serenella M; Di Nicola, Massimo

    2015-03-12

    We have shown that human B-cell non-Hodgkin lymphomas (B-NHLs) express heat shock protein (HSP)H1/105 in function of their aggressiveness. Here, we now clarify its role as a functional B-NHL target by testing the hypothesis that it promotes the stabilization of key lymphoma oncoproteins. HSPH1 silencing in 4 models of aggressive B-NHLs was paralleled by Bcl-6 and c-Myc downregulation. In vitro and in vivo analysis of HSPH1-silenced Namalwa cells showed that this effect was associated with a significant growth delay and the loss of tumorigenicity when 10(4) cells were injected into mice. Interestingly, we found that HSPH1 physically interacts with c-Myc and Bcl-6 in both Namalwa cells and primary aggressive B-NHLs. Accordingly, expression of HSPH1 and either c-Myc or Bcl-6 positively correlated in these diseases. Our study indicates that HSPH1 concurrently favors the expression of 2 key lymphoma oncoproteins, thus confirming its candidacy as a valuable therapeutic target of aggressive B-NHLs.

  20. Abrupt reduction of c-myc expression by antisense RNA inducing terminal differentiation and apoptosis of a human esophageal cancer cell line

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    赵晓航; 王秀琴; 周传农; 彭仁玲; 阎水中; 吴旻

    1995-01-01

    A human esophageal cancer cell line (EC8712) expressing high-level Myc protein was infected with recombmant retroviral particles (pA-BD9) at a multiplicity of infection (MOI) 1:1. This viral particle contains a neomycin-resistant gene and a 1.53-kb antisense RNA spanning the 2nd exon and its flanking sequences of the human c-myc oncogene. The G418-resistant EC8712 clones showed an 86% inhibition of growth rate and morphological changes characteristic of terminal differentiation and apoptosis. A decrease of about 80% of Myc protein was also observed in these infected cells by ABC-ELISA assay. 12-24 h after the infection of ECS712 cells with pA-BD9 at a high viral particle concentration (MOI = 1:10), the integration of the extrinsic 1.53-kb antisense c-myc fragment into the cancer cell genome was evidenced by the Southern blot analysis. Northern blot analyses showed the expression of this antisense fragment and a decrease of the intrinsic c-myc expression by 74% in comparison with that of the parental EC8

  1. INCREASED EXPRESSION OF PDGF AND C-MYC GENES IN LUNGS AND PULMONARY ARTERIES OF PULMONARY HYPERTENSIVE RATS INDUCED BY HYPOXIA

    Institute of Scientific and Technical Information of China (English)

    蔡英年; 韩梅; 罗兰; 宋为; 周晓梅

    1996-01-01

    The role of growth factors and proto-oncogene in pulmonary vascular structural remodelling is not well known.The present study examined gene expression of plateler-derived growth factor(PDGF)-A and -B chain and proto-oncogene,c-myc,in lung tissue and pulmonary artery of rats exposed to hypoxia and compred to those levels of gene expression in normal rats.Normal lungs and pulmonary artery expressed PDGF-A chain transcripr of 1.7kb and PDGF-B chain transcript of 3.5 Kb. The c-myc transcript of 2.2 kb was expressed as well.After hypoxic exposure for 7 and 14 days mRNA levels of PDGF-B chain and c-myc were elevated significantly compared with those of control rats.PDGF-A chain mRNA increased after hypoxia for 7 days,and then declined.These results suggest that activation of sutocrine and /or paracrine is important in proliferation mechanism of pulmonary artery smooth muscle cells in bypoxic pulmonary hypertensive rats.

  2. Induction of C-FOS, C-MYC and P53 by US -adrenergic receptor (US -AR) stimulation of rat parotid acinar cells (RPAC)

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    Kousvelari, E.E.; Louis, J.; Curran, T.; Baum, B.J.

    1987-05-01

    Treatment of rats with the US -agonist isoproterenol (ISO) results in dramatically increased parotid gland protein synthesis, processing and cell proliferation. The authors have shown that in RPAC in vitro, US -AR stimulation has similar effect on protein synthesis and processing. Proto-oncogenes have been implicated in growth regulation, differentiation and in mediating some extracellular stimulated events at the level of gene expression. To understand the regulation of cellular events after US -AR stimulation, the expression of c-fos, c-myc and p53 was investigated. RPAC were incubated with or without 10 VM ISO for 15, 30, 60 min. mRNA was isolated from cells and hybridization analysis was performed on nitrocellulose paper-transferred mRNA using TSP-labeled DNA probes. At early time points, the levels of c-fos gene activation in ISO-treated and control cells were comparable. After 60 min of ISO treatment, a sharp 20-30 fold induction of c-fos expression occurred. Similar increases in c-myc and p53 gene expression were observed after 60 min of ISO treatment. The authors data indicate that early effects of US -AR stimulation of RPAC include induction of c-fos, c-myc and p53 gene expression as well as enhanced protein synthesis and processing.

  3. Diet-induced obesity promotes murine gastric cancer growth through a nampt/sirt1/c-myc positive feedback loop.

    Science.gov (United States)

    Li, Hai-Jun; Che, Xiang-Ming; Zhao, Wei; He, Shi-Cai; Zhang, Zheng-Liang; Chen, Rui; Fan, Lin; Jia, Zong-Liang

    2013-11-01

    Obesity increases the risk of gastric cancer and may promote its growth, as was recently demonstrated by our novel in vivo mouse model. However, the underlying mechanisms of this correlation remain unclear. The purpose of this study was to investigate the precise effects of obesity on gastric cancer growth and to elucidate the potential molecular mechanisms. Diet-induced obese mice were insulin-resistant, glucose-intolerant and had high serum visfatin concentration. In the subcutaneous mouse model, tumors were more aggressive in diet-induced obese mice compared with lean mice. Tumor weights showed a significant positive correlation with mouse body weights, as well as serum insulin and visfatin concentrations. Immunohistochemical staining showed that the expression levels of iNampt, Sirt1 and c-MYC proteins were upregulated in the subcutaneous tumors from obese mice compared to those from lean animals. Furthermore, obesity not only prompted significantly murine forestomach carcinoma cell migration, proliferation, but also affected cellular apoptosis and cell cycle by endocrine mechanisms. These were associated with increased expression of the pro-survival nampt/sirt1/c-myc positive feedback loop confirmed by RT-PCR and western blotting. These results suggested that diet-induced obesity could promote murine gastric cancer growth by upregulating the expression of the nampt, sirt1 and c-myc genes.

  4. A Novel PTEN/Mutant p53/c-Myc/Bcl-XL Axis Mediates Context-Dependent Oncogenic Effects of PTEN with Implications for Cancer Prognosis and Therapy

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    Xiaoping Huang

    2013-08-01

    Full Text Available Phosphatase and tensin homolog located on chromosome 10 (PTEN is one of the most frequently mutated tumor suppressors in human cancer including in glioblastoma. Here, we show that PTEN exerts unconventional oncogenic effects in glioblastoma through a novel PTEN/mutant p53/c-Myc/Bcl-XL molecular and functional axis. Using a wide array of molecular, genetic, and functional approaches, we demonstrate that PTEN enhances a transcriptional complex containing gain-of-function mutant p53, CBP, and NFY in human glioblastoma cells and tumor tissues. The mutant p53/CBP/NFY complex transcriptionally activates the oncogenes c-Myc and Bcl-XL, leading to increased cell proliferation, survival, invasion, and clonogenicity. Disruption of the mutant p53/c-Myc/Bcl-XL axis or mutant p53/CBP/NFY complex reverses the transcriptional and oncogenic effects of PTEN and unmasks its tumor-suppressive function. Consistent with these data, we find that PTEN expression is associated with worse patient survival than PTEN loss in tumors harboring mutant p53 and that a small molecule modulator of p53 exerts greater antitumor effects in PTEN-expressing cancer cells. Altogether, our study describes a new signaling pathway that mediates context-dependent oncogenic/tumor-suppressive role of PTEN. The data also indicate that the combined mutational status of PTEN and p53 influences cancer prognosis and anticancer therapies that target PTEN and p53.

  5. The c-myc mRNA and helicobacter pylori infection and the relationship between the programmed cell death in the with Gastric cancer in the patients with gastric cancer%胃癌变患者c-myc mRNA与幽门螺杆菌感染及细胞程序性死亡的关系

    Institute of Scientific and Technical Information of China (English)

    潘晟; 罗浩; 李力

    2013-01-01

    Objective To discuss different stomach trouble change occurred in the process of development until the progression in patients with c-myc mRNA expression in correlation with helicobacter pylori (Hp) infection and its relationship with gastric tissue programmed cell death.Methods By real-time fluorescent quantitative reverse transcription-olymerase chain reaction (FQ-PCR) to detect 72 cases of chronic superficial gastritis (CSG),55 cases of chronic atrophic gastritis (the CAG),52 cases of intestinal metaplasia (IM),46 cases of atypical hyperplasia (AH),65 cases of gastric cancer (GC) group (CSG group,respectively,the CAG group,IM,AM group,AH,the GC group) in the c-myc mRNA expression;Rapid enzymatic urea,Warthin Starry silver staining and toluidine blue staining assay for gastric mucosa Hp infection;In situ end labeling (TUNEL) method to detect gastric mucosal cell apoptosis index (AI).Results CSG group,the CAG group,IM,AM group,AH,the GC group c-myc in gastric mucosa tissue mRNA positive example were 21.5% (7/31),31.0% (8/27),41.0% (10/26),59.1% (14/24) and 69.1 (23/33),c-myc relative mRNA expression levels were 0.089 ± 0.002,0.01 13 ± 0.014 mm,0.168 ±0.028,0.226,0.367 ±0.037 mm,0.040 mm IM,AH group,GC group c-myc amount of mRNA expression were higher than in CSG,the CAG group (P < 0.01),the AH group is higher than the IM group (P <0.01),the GC group higher than IM,AH group (P <0.01).C-myc mRNA expression quantity and negatively correlated with gastric mucosa cells AI (rs =-0.700,P <0.05) ;IM,AH group,GC group Hp positive patients with gastric mucosa cell c-myc mRNA expression were higher than Hp negative patients (P <0.05 or 0.01).Conclusion In the process of the gastric mucosal canceration,Hp infection can increase gastric mucosa cell c-myc mRNA expression,and inhibition of special-shaped programmed cell death (apoptosis) and play a role of cancer.%目的 探讨不同胃病变患者的发生发展直至恶变过程中c-myc mRNA的表达与

  6. 艾灸对实验性类风湿关节炎滑膜细胞原癌基因 c-fos和c-myc mRNA表达的影响%Effects of moxibustion on the expression of protooncogene c-fos and c-myc mRNA in experimental arthritis

    Institute of Scientific and Technical Information of China (English)

    余俊辉; 刘旭光; 余曙光; 蔡美英; 周昌华; 赵宗蓉; 张平

    2005-01-01

    目的观察艾灸对实验性类风湿关节炎滑膜细胞原癌基因c-fos、c-myc mRNA表达的影响,初步探讨艾灸对RA滑膜细胞内分子信号传导的调控.方法在日本大耳白兔右后足踝关节部皮内注射福氏完全佐剂造模,经过艾灸治疗,通过半定量RT-PCR测定c-fos和c-myc mRNA的表达量.结果治疗组c-fos和c-myc mRNA表达量显著低于造模组(P<0.01).结论艾灸治疗能够降低c-fos和c-myc mRNA的表达,影响生长因子信号传导系统.

  7. C-MYC and BCL2 translocation frequency in diffuse large B-cell lymphomas: A study of 97 patients

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    Bahar Akkaya

    2016-01-01

    Full Text Available Purpose: Diffuse large B-cell lymphoma (DLBCL is an aggressive non-Hodgkin lymphoma with marked biologic heterogeneity. MYC and BCL2 rearrangements have been reported in a proportion of DLBCLs, where they may be associated with an adverse clinical outcome. The aim of this study was to determine the frequency of MYC and BCL2 translocations in DLBCL and assess the prognostic impact in DLBCL patients. Materials and Methods:   In the present study, we evaluated the expression patterns of CD 10, BCL6, and MUM 1 by immunohistochemistry in 121 cases with DLBCL in tissue microarray (TMA: 62 cases in germinal center B-cells (GCBs; and 59 cases in activated B-cells (ABCs of which 60 were females and 61 were males. MYC and BCL2 rearrangements were investigated by interphase fluorescence in situ hybridization on TMAs in 97 DLBCLs. Result: MYC rearrangements were observed in 11 of 97 cases. There was no association with other clinical features, including age, sex, and nodal/extranodal disease. MYC rearrangement was associated with significantly worse overall survival (P < 0.01. BCL2 rearrangements were observed in 14 of 97 cases. There was no association with other clinical features including age and sex. BCL2 rearrangement had a worse outcome (P < 0.01. MYC and BCL2 rearrangements were observed in 3 of 97 cases with the age of  53 (female, 53, 63 years old, respectively, died in 24, 18, and 35 months after the diagnosis. Two cases had primary nodal and one case primary extranodal presentations. All these patients had stage IV disease. Conclusion: We concluded that C-MYC and BCL2 may contribute to aggressive transformation, and more mechanism-based therapy should be explored. Targeted therapies involving these rearrangements and its associated pathways may change the fate of DLBCLs. Analysis of MYC gene rearrangement along with BCL2 is critical in the identification of high-risk patients with poor prognosis.

  8. Nodal diffuse large B-cell lymphomas in children and adolescents: immunohistochemical expression patterns and c-MYC translocation in relation to clinical outcome.

    Science.gov (United States)

    Gualco, Gabriela; Weiss, Lawrence M; Harrington, William J; Bacchi, Carlos E

    2009-12-01

    Diffuse large B-cell lymphoma (DLBCL) is a very infrequent neoplasm in the pediatric age group; therefore there are very few studies on the immunophenotype or genetics of these cases. We studied a series of 16 patients with nodal DLBCL occurring in patients between 10 and 18 years of age. The cases were classified according to the 2008 World Health Organization classification criteria, with application of immunohistochemistry for the detection of CD10, BCL-6, and MUM1 proteins to divide the lymphomas into germinal center and nongerminal center types. In addition, TCL1, BCL-2 expression, and the Ki-67 proliferation index were evaluated by immunohistochemistry, and c-MYC and BCL2 translocations were evaluated by fluorescence in situ hybridization. All these parameters were correlated with clinical features and outcome. Our study revealed that centroblastic morphology and the germinal center type of DLBCL are more prevalent in these young patients (63%), with 37% containing a c-MYC translocation. Only 1 case showed a BCL2 translocation, reflecting a double-hit case with features intermediate between DLBCL and Burkitt lymphoma. We found a higher frequency of BCL-2 expression than previously reported, with no direct influence on the outcome of the disease in univariate or multivariate analysis. The expression of TCL1 has not been specifically studied in nodal pediatric DLBCL before; we found a 31% incidence of TCL1 expression. MUM1 expression was observed in 44% of the cases and these positive cases showed a significant negative impact on clinical outcome. TCL1 is directly and significantly associated with the presence of c-MYC and a high proliferative index. The germinal center and nongerminal center subtypes showed significant differences for both overall survival and disease-free interval. c-MYC translocation was found in 37% of patients, and had a favorable impact on clinical outcome. We conclude that nodal pediatric and adolescent DLBCL are mainly of the germinal

  9. Physiological Expression and Accumulation of the Products of Two Upstream Open Reading Frames mrtl and MycHex1 Along With p64 and p67 Myc From the Human c-myc Locus.

    Science.gov (United States)

    Ji, Mi Hong; Kim, Seung-Ki; Kim, Chae-Yong; Phi, Ji Hoon; Jun, Hyun Jin; Blume, Scott W; Choi, Hyoung Soo

    2016-06-01

    In addition to the canonical c-Myc p64 and p67 proteins, the human c-myc locus encodes two distinct proteins, mrtl (myc-related translation/localization regulatory factor) and MycHex1 (Myc Human Exon 1), from the upstream open reading frames within the 5'-untranslated region of the c-myc P0 mRNA. The aim of this study is to examine simultaneously, for the first time, mrtl, MycHex1, c-Myc p64, and p67 in human tumor cell lines and pediatric brain tumor tissues. Western blot analysis demonstrated endogenous mrtl, MycHex1, c-Myc p64, and p67 simultaneously. The relative abundance of mrtl and MycHex1 were consistent among a variety of human tumor cell lines, and the relative intensities of mrtl and MycHex1 correlated positively. Confocal imaging revealed mrtl predominantly localized to the nuclear envelope, along with prominent reticular pattern in the cytoplasm. MycHex1 was observed as a series of bright foci located within the nucleus, a subset of which colocalized with fibrillarin. mrtl and MycHex1 co-immunoprecipitated with RACK1, c-Myc, fibrillarin, coilin, and with each other. These findings suggest that mrtl and MycHex1 have multiple interaction partners in both the nucleus and cytoplasm. Sequence analyses confirmed a known polymorphism of mrtl at base 1965 (G>T) and new mutations at bases 1900 (C>G) and 1798 (C>G). Evidence is presented for expression and stable accumulation of all four proteins encoded by three distinct non-overlapping open reading frames within the human c-myc locus. Additional work is warranted to further elucidate the functional or regulatory roles of these molecules in regulation of c-Myc and in oncogenesis.

  10. Chromosomal and Extrachromosomal Instability of the cyclin D2 Gene is Induced by Myc Overexpression

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    Sabine Mai

    1999-08-01

    Full Text Available We examined the expression of cyclins D1, D2, D3, and E in mouse B-lymphocytic tumors. Cyclin D2 mRNA was consistently elevated in plasmacytomas, which characteristically contain Myc-activating chromosome translocations and constitutive c-Myc mRNA and protein expression. We examined the nature of cyclin D2 overexpression in plasmacytomas and other tumors. Human and mouse tumor cell lines that exhibited c-Myc dysregulation displayed instability of the cyclin D2 gene, detected by Southern blot, fluorescent in situ hybridization (FISH, and in extrachromosomal preparations (Hirt extracts. Cyclin D2 instability was not seen in cells with low levels of c-Myc protein. To unequivocally demonstrate a role of c-Myc in the instability of the cyclin D2 gene, a Myc-estrogen receptor chimera was activated in two mouse cell lines. After 3 to 4 days of Myc-ERTm activation, instability at the cyclin D2 locus was seen in the form of extrachromosomal elements, determined by FISH of metaphase and interphase nuclei and of purified extrachromosomal elements. At the same time points, Northern and Western blot analyses detected increased cyclin D2 mRNA and protein levels. These data suggest that Myc-induced genomic instability may contribute to neoplasia by increasing the levels of a cell cycle—regulating protein, cyclin D2, via intrachromosomal amplification of its gene or generation of extrachromosomal copies.

  11. 氧化苦参碱对结肠癌LoVo细胞c-myc,PSMD9,CDK4mRNA表达的影响%Effect of Oxymatrine on Expression of c-myc, PSMD9 and CDK4 mRNA in Human Colon Carcinoma LoVo Cells

    Institute of Scientific and Technical Information of China (English)

    彭燕; 韩凌; 孙静; 危建安

    2012-01-01

    目的:探讨氧化苦参碱( oxymatrine,OM)抑制人结肠癌LoVo细胞增殖和诱导凋亡的分子作用机制.方法:采用流式细胞仪检测LoVo细胞凋亡率以及细胞周期分布;采用荧光定量PCR法检测0.25,0.5 g·L-1 OM对LoVo细胞增殖相关基因c -myc,蛋白酶调解因子9(PSMD9),CDK4的基因表达的影响.结果:0.5 g·L-1以下浓度的OM作用结肠癌LoVo细胞48 h,对细胞凋亡无明显影响.0.25 g·L-1 OM作用48 h时可明显抑制人结肠癌LoVo细胞c-myc基因表达(P<0.05).0.5g·L-1 OM作用48 h时可明显抑制LoVo细胞c-myc,CDK4的基因表达(P <0.01,P<0.01,).药物作用时间为96 h时,0.5g·L-1 OM可明显抑制c-myc,PSM D9,CDK4基因表达(P<0.05,或P<0.01).结论:较低剂量OM显著抑制人结肠癌LoVo细胞增殖的作用机制,可能与下调LoVo细胞c-myc,PSM D9,CDK4表达有关.%Objective: To explore the molecular mechanism of inhibiting colon cancer cell strein LoVo proliferation and inducing apoptosis by oxymatrine ( OM ) Method: Flow cytometry was used to detect the LoVo cells apoptosis and cell cycle distribution. Fluorescence quantitative PCR was used to detect cell proliferation-related genes like the c-myc, proteasome modulator 9 (PSMD9) , CDK4 gene expression when LoVo was treated with 0. 25, 0. 5 g · L-1OM. Result: OM had no significant effect on apoptosis in colon cancer LoVo cells when the treatment of OM lasted 48 h and the concentration was lower than 0.5, 0.25 g · L-1 OM can inhibit c-myc gene expression in LoVo when duration of action last 24 h ( P < 0. 05 ). When the dose increated to 0. 5 g · L-1 and duration of action was 48 h, OM could inhibit c-myc, CDK4 gene expression in LoVo cells (P <0. 01 , P < 0. 01). When duration of action was extended to 96 h, 0. 5 g · L-1 OM could inhibit the c-myc, PSMD9, CDK4 gene expression in LoVo cells ( P < 0. 05, P < 0. 01, P < 0. 01 ). Conclusion; OM at Lower dose could significantly inhibit the proliferation of human colon cancer Lo

  12. C-Myc induced compensated cardiac hypertrophy increases free fatty acid utilization for the citric acid cycle.

    Science.gov (United States)

    Olson, Aaron K; Ledee, Dolena; Iwamoto, Kate; Kajimoto, Masaki; O'Kelly Priddy, Colleen; Isern, Nancy; Portman, Michael A

    2013-02-01

    The protooncogene C-Myc (Myc) regulates cardiac hypertrophy. Myc promotes compensated cardiac function, suggesting that the operative mechanisms differ from those leading to heart failure. Myc regulation of substrate metabolism is a reasonable target, as Myc alters metabolism in other tissues. We hypothesize that Myc induced shifts in substrate utilization signal and promote compensated hypertrophy. We used cardiac specific Myc-inducible C57/BL6 male mice between 4-6 months old that develop hypertrophy with tamoxifen (tam) injections. Isolated working hearts and (13)Carbon ((13)C)-NMR were used to measure function and fractional contributions (Fc) to the citric acid cycle by using perfusate containing (13)C-labeled free fatty acids, acetoacetate, lactate, unlabeled glucose and insulin. Studies were performed at pre-hypertrophy (3-days tam, 3dMyc), established hypertrophy (7-days tam, 7dMyc) or vehicle control (Cont). Non-transgenic siblings (NTG) received 7-days tam or vehicle to assess drug effect. Hypertrophy was assessed by echocardiograms and heart weights. Western blots were performed on key metabolic enzymes. Hypertrophy occurred in 7dMyc only. Cardiac function did not differ between groups. Tam alone did not affect substrate contributions in NTG. Substrate utilization was not significantly altered in 3dMyc versus Cont. The free fatty acid FC was significantly greater in 7dMyc versus Cont with decreased unlabeled Fc, which is predominately exogenous glucose. Free fatty acid flux to the citric acid cycle increased while lactate flux was diminished in 7dMyc compared to Cont. Total protein levels of a panel of key metabolic enzymes were unchanged; however total protein O-GlcNAcylation was increased in 7dMyc. Substrate utilization changes for the citric acid cycle did not precede hypertrophy; therefore they are not the primary signal for cardiac growth in this model. Free fatty acid utilization and oxidation increase at established hypertrophy. Understanding the

  13. C-Myc Induced Compensated Cardiac Hypertrophy Increases Free Fatty Acid Utilization for the Citric Acid Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Aaron; Ledee, Dolena; Iwamoto, Kate; Kajimoto, Masaki; O' Kelly-Priddy, Colleen M.; Isern, Nancy G.; Portman, Michael A.

    2013-02-01

    The protooncogene C-Myc (Myc) regulates cardiac hypertrophy. Myc promotes compensated cardiac function, suggesting that the operative mechanisms differ from those leading to heart failure. Myc regulation of substrate metabolism is a reasonable target, as Myc alters metabolism in other tissues. We hypothesize that Myc-induced shifts in substrate utilization signal and promote compensated hypertrophy. We used cardiac specific Myc-inducible C57/BL6 male mice between 4-6 months old that develop hypertrophy with tamoxifen (tam). Isolated working hearts and 13Carbon (13C )-NMR were used to measure function and fractional contributions (Fc) to the citric acid cycle by using perfusate containing 13C-labeled free fatty acids, acetoacetate, lactate, unlabeled glucose and insulin. Studies were performed at pre-hypertrophy (3-days tam, 3dMyc), established hypertrophy (7-days tam, 7dMyc) or vehicle control (cont). Non-transgenic siblings (NTG) received 7-days tam or vehicle to assess drug effect. Hypertrophy was confirmed by echocardiograms and heart weights. Western blots were performed on key metabolic enzymes. Hypertrophy occurred in 7dMyc only. Cardiac function did not differ between groups. Tam alone did not affect substrate contribution in NTG. Substrate utilization was not significantly altered in 3dMyc versus cont. The free fatty acid FC was significantly greater in 7dMyc vs cont with decreased unlabeled Fc, which is predominately exogenous glucose. Free fatty acid flux to the citric acid cycle increased while lactate flux was diminished in 7dMyc compared to cont. Total protein levels of a panel of key metabolic enzymes were unchanged; however total protein O-GlcNAcylation was increased in 7dMyc. Substrate utilization changes did not precede hypertrophy; therefore they are not the primary signal for cardiac growth in this model. Free fatty acid utilization and oxidation increase at established hypertrophy. Understanding the mechanisms whereby this change maintained

  14. Liver tumor formation by a mutant retinoblastoma protein in the transgenic mice is caused by an upregulation of c-Myc target genes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Hikosaka, Keisuke; Sultana, Nishat; Sharkar, Mohammad Tofael Kabir [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Noritake, Hidenao [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Kimura, Wataru; Wu, Yi-Xin [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Kobayashi, Yoshimasa [Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Uezato, Tadayoshi [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Miura, Naoyuki, E-mail: nmiura@hama-med.ac.jp [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Fifty percent of the mutant Rb transgenic mice produced liver tumors. Black-Right-Pointing-Pointer In the tumor, Foxm1, Skp2, Bmi1 and AP-1 mRNAs were up-regulated. Black-Right-Pointing-Pointer No increase in expression of the Myc-target genes was observed in the non-tumorous liver. Black-Right-Pointing-Pointer Tumor formation depends on up-regulation of the Myc-target genes. -- Abstract: The retinoblastoma (Rb) tumor suppressor encodes a nuclear phosphoprotein that regulates cellular proliferation, apoptosis and differentiation. In order to adapt itself to these biological functions, Rb is subjected to modification cycle, phosphorylation and dephosphorylation. To directly determine the effect of phosphorylation-resistant Rb on liver development and function, we generated transgenic mice expressing phosphorylation-resistant human mutant Rb (mt-Rb) under the control of the rat hepatocyte nuclear factor-1 gene promoter/enhancer. Expression of mt-Rb in the liver resulted in macroscopic neoplastic nodules (adenomas) with {approx}50% incidence within 15 months old. Interestingly, quantitative reverse transcriptase-PCR analysis showed that c-Myc was up-regulated in the liver of mt-Rb transgenic mice irrespective of having tumor tissues or no tumor. In tumor tissues, several c-Myc target genes, Foxm1, c-Jun, c-Fos, Bmi1 and Skp2, were also up-regulated dramatically. We determined whether mt-Rb activated the Myc promoter in the HTP9 cells and demonstrated that mt-Rb acted as an inhibitor of wild-type Rb-induced repression on the Myc promoter. Our results suggest that continued upregulation of c-Myc target genes promotes the liver tumor formation after about 1 year of age.

  15. AID induces double-strand breaks at immunoglobulin switch regions and c-MYC causing chromosomal translocations in yeast THO mutants.

    Science.gov (United States)

    Ruiz, José F; Gómez-González, Belén; Aguilera, Andrés

    2011-02-01

    Transcription of the switch (S) regions of immunoglobulin genes in B cells generates stable R-loops that are targeted by Activation Induced Cytidine Deaminase (AID), triggering class switch recombination (CSR), as well as translocations with c-MYC responsible for Burkitt's lymphomas. In Saccharomyces cerevisiae, stable R-loops are formed co-transcriptionally in mutants of THO, a conserved nuclear complex involved in mRNP biogenesis. Such R-loops trigger genome instability and facilitate deamination by human AID. To understand the mechanisms that generate genome instability mediated by mRNP biogenesis impairment and by AID, we devised a yeast chromosomal system based on different segments of mammalian S regions and c-MYC for the analysis of chromosomal rearrangements in both wild-type and THO mutants. We demonstrate that AID acts in yeast at heterologous S and c-MYC transcribed sequences leading to double-strand breaks (DSBs) which in turn cause chromosomal translocations via Non-Homologous End Joining (NHEJ). AID-induced translocations were strongly enhanced in yeast THO null mutants, consistent with the idea that AID-mediated DSBs depend on R-loop formation. Our study not only provides new clues to understand the role of mRNP biogenesis in preventing genome rearrangements and the mechanism of AID-mediated genome instability, but also shows that, once uracil residues are produced by AID-mediated deamination, these are processed into DSBs and chromosomal rearrangements by the general and conserved DNA repair functions present from yeast to human cells.

  16. AID induces double-strand breaks at immunoglobulin switch regions and c-MYC causing chromosomal translocations in yeast THO mutants.

    Directory of Open Access Journals (Sweden)

    José F Ruiz

    2011-02-01

    Full Text Available Transcription of the switch (S regions of immunoglobulin genes in B cells generates stable R-loops that are targeted by Activation Induced Cytidine Deaminase (AID, triggering class switch recombination (CSR, as well as translocations with c-MYC responsible for Burkitt's lymphomas. In Saccharomyces cerevisiae, stable R-loops are formed co-transcriptionally in mutants of THO, a conserved nuclear complex involved in mRNP biogenesis. Such R-loops trigger genome instability and facilitate deamination by human AID. To understand the mechanisms that generate genome instability mediated by mRNP biogenesis impairment and by AID, we devised a yeast chromosomal system based on different segments of mammalian S regions and c-MYC for the analysis of chromosomal rearrangements in both wild-type and THO mutants. We demonstrate that AID acts in yeast at heterologous S and c-MYC transcribed sequences leading to double-strand breaks (DSBs which in turn cause chromosomal translocations via Non-Homologous End Joining (NHEJ. AID-induced translocations were strongly enhanced in yeast THO null mutants, consistent with the idea that AID-mediated DSBs depend on R-loop formation. Our study not only provides new clues to understand the role of mRNP biogenesis in preventing genome rearrangements and the mechanism of AID-mediated genome instability, but also shows that, once uracil residues are produced by AID-mediated deamination, these are processed into DSBs and chromosomal rearrangements by the general and conserved DNA repair functions present from yeast to human cells.

  17. The effect of non-coding DNA variations on P53 and cMYC competitive inhibition at cis-overlapping motifs.

    Science.gov (United States)

    Kin, Katherine; Chen, Xi; Gonzalez-Garay, Manuel; Fakhouri, Walid D

    2016-04-15

    Non-coding DNA variations play a critical role in increasing the risk for development of common complex diseases, and account for the majority of SNPs highly associated with cancer. However, it remains a challenge to identify etiologic variants and to predict their pathological effects on target gene expression for clinical purposes. Cis-overlapping motifs (COMs) are elements of enhancer regions that impact gene expression by enabling competitive binding and switching between transcription factors. Mutations within COMs are especially important when the involved transcription factors have opposing effects on gene regulation, like P53 tumor suppressor and cMYC proto-oncogene. In this study, genome-wide analysis of ChIP-seq data from human cancer and mouse embryonic cells identified a significant number of putative regulatory elements with signals for both P53 and cMYC. Each co-occupied element contains, on average, two COMs, and one common SNP every two COMs. Gene ontology of predicted target genes for COMs showed that the majority are involved in DNA damage, apoptosis, cell cycle regulation, and RNA processing. EMSA results showed that both cMYC and P53 bind to cis-overlapping motifs within a ChIP-seq co-occupied region in Chr12. In vitro functional analysis of selected co-occupied elements verified enhancer activity, and also showed that the occurrence of SNPs within three COMs significantly altered enhancer activity. We identified a list of COM-associated functional SNPs that are in close proximity to SNPs associated with common diseases in large population studies. These results suggest a potential molecular mechanism to identify etiologic regulatory mutations associated with common diseases.

  18. Surface-enhanced raman scattering surface selection rules for the proteomic liquid biopsy in real samples: Efficient detection of the oncoprotein c-MYC

    OpenAIRE

    2016-01-01

    NOTICE: This is the peer reviewed version of the following article: Elena Pazos, Manuel García-Algar, Cristina Penas, Moritz Nazarenus, Arnau Torruella, Nicolas Pazos-Perez, Luca Guerrini, M. Eugenio Vázquez, Eduardo Garcia-Rio*, José L. Macareñas* and Ramon A. Alvarez-Puebla* (2016), SERS Surface Selection Rules for the Proteomic Liquid Biopsy in Real Samples: Efficient Detection of the Oncoprotein c-MYC. J. Am. Chem. Soc., 138, 14206-14209 [DOI:10.1021/jacs.6b08957]. This article may be use...

  19. Angiotensin II reduces cardiac AdipoR1 expression through AT1 receptor/ROS/ERK1/2/c-Myc pathway.

    Directory of Open Access Journals (Sweden)

    Li Li

    Full Text Available Adiponectin, an abundant adipose tissue-derived protein, exerts protective effect against cardiovascular disease. Adiponectin receptors (AdipoR1 and AdipoR2 mediate the beneficial effects of adiponectin on the cardiovascular system. However, the alteration of AdipoRs in cardiac remodeling is not fully elucidated. Here, we investigated the effect of angiotensin II (AngII on cardiac AdipoRs expression and explored the possible molecular mechanism. AngII infusion into rats induced cardiac hypertrophy, reduced AdipoR1 but not AdipoR2 expression, and attenuated the phosphorylations of adenosine monophosphate-activated protein kinase and acetyl coenzyme A carboxylase, and those effects were all reversed by losartan, an AngII type 1 (AT1 receptor blocker. AngII reduced expression of AdipoR1 mRNA and protein in cultured neonatal rat cardiomyocytes, which was abolished by losartan, but not by PD123319, an AT2 receptor antagonist. The antioxidants including reactive oxygen species (ROS scavenger NAC, NADPH oxidase inhibitor apocynin, Nox2 inhibitor peptide gp91 ds-tat, and mitochondrial electron transport chain complex I inhibitor rotenone attenuated AngII-induced production of ROS and phosphorylation of extracellular signal-regulated kinase (ERK 1/2. AngII-reduced AdipoR1 expression was reversed by pretreatment with NAC, apocynin, gp91 ds-tat, rotenone, and an ERK1/2 inhibitor PD98059. Chromatin immunoprecipitation assay demonstrated that AngII provoked the recruitment of c-Myc onto the promoter region of AdipoR1, which was attenuated by PD98059. Moreover, AngII-induced DNA binding activity of c-Myc was inhibited by losartan, NAC, apocynin, gp91 ds-tat, rotenone, and PD98059. c-Myc small interfering RNA abolished the inhibitory effect of AngII on AdipoR1 expression. Our results suggest that AngII inhibits cardiac AdipoR1 expression in vivo and in vitro and AT1 receptor/ROS/ERK1/2/c-Myc pathway is required for the downregulation of AdipoR1 induced by AngII.

  20. Molecular cloning of MSSP-2, a c-myc gene single-strand binding protein: characterization of binding specificity and DNA replication activity.

    OpenAIRE

    Takai, Toshiki; Nishita, Yoshinori; Iguchi-Ariga, Sanae M. M.; Ariga, Hiroyoshi

    1994-01-01

    We have previously reported the human cDNA encoding MSSP-1, a sequence-specific double- and single-stranded DNA binding protein [Negishi, Nishita, Saëgusa, Kakizaki, Galli, Kihara, Tamai, Miyajima, Iguchi-Ariga and Ariga (1994) Oncogene, 9, 1133-1143]. MSSP-1 binds to a DNA replication origin/transcriptional enhancer of the human c-myc gene and has turned out to be identical with Scr2, a human protein which complements the defect of cdc2 kinase in S.pombe [Kataoka and Nojima (1994) Nucleic Ac...

  1. DJ-1, an oncogene and causative gene for familial Parkinson's disease, is essential for SV40 transformation in mouse fibroblasts through up-regulation of c-Myc

    OpenAIRE

    Kim, Yun Chul; Kitaura, Hirotake; Iguchi-Ariga, Sanae M. M.; Ariga, Hiroyoshi

    2010-01-01

    Simian virus 40 (SV40) is a tumor virus and its early gene product large T-antigen (LT) is responsible for the transforming activity of SV40. Parkinson's disease causative gene DJ-1 is also a ras-dependent oncogene, but the mechanism of its oncogene function is still not known. In this study, we found that there were no transformed foci when fibroblasts from DJ-1-knockout mice were transfected with LT. We also found that DJ-1 directly bound to LT and that the expression level of c-Myc in tran...

  2. Effect of hydroxyapatite nanoparticles on the growth and p53/c-Myc protein expression of implanted hepatic VX2 tumor in rabbits by intravenous injection

    Institute of Scientific and Technical Information of China (English)

    Jun Hu; Zhi-Su Liu; Sheng-Li Tang; Yue-Ming He

    2007-01-01

    AIM:To evaluate the effect of hydroxyapatite nanoparticles (Nano HAP) by intravenous injection on the inhibition of implanted hepatic VX2 tumor growth in rabbits and cell p53/c-Myc protein expression.METHODS: 60 hepatic VX2 tumor-bearing rabbits was randomly divided into five groups. Nano HAP collosol 20 mg/kg, 40 mg/kg, 5-FU solutions 20 mg/mL, mixed liquor of 5-FU solution 20 mg/mL and Nano HAP collosol 20 mg/kg were infused by vein, normal saline conducted as the control. The general state, weight, liver function and gross tumor volume were detected dynamically.The expression of p53 and c-Myc gene protein in tumor tissue was detected by immunohistochemistry methods.RESULTS: The growth of implanted hepatic VX2 tumors was significantly inhibited in all therapy groups, 3 wk after the injection, the tumor control rates in Nano HAP collosol groups were 25.5% and 32.5% respectively,and the gross tumor volumes were obviously less than that of control group. (24.81 ± 5.17 and 22.73 ± 4.23vs 33.32 ± 5.26, P < 0.05). The tumor control rate of 5-FU group was 43.7% (18.74 ± 4.40 vs 33.32 ± 5.26,P < 0.05), but the general state of the animals after injection aggravated; and the adverse reaction in the drug combination group obviously decreased. Due to the effect of Nano HAP, the positive expression of tumor associated the mutated p53 and c-Myc in tumor tissue was decreased obviously compared with the control group.CONCLUSION: Nano HAP has evident inhibitory action on rabbit implanted hepatic VX2 tumor in vivo, which may be the result of decreasing the expression of the mutated p53 and c-myc, and drug combination can obviously decrease the adverse reaction of 5-FU.

  3. 阴道脱落细胞检查联合人类染色体末端酶基因、c-myc 检测在宫颈癌诊断中的价值%The clinical value of Thinprep cytology test combined with h -TERC and c -myc in the diagnosis of cervical ;cancer

    Institute of Scientific and Technical Information of China (English)

    毛海波

    2015-01-01

    Objective To explore the clinical value of Thinprep cytology test (TCT)combined with h -TERC and c -myc in the diagnosis of cervical cancer.Methods hTERC amplification was detected by dual -color interphase fluorescence in situ hybridization (FISH),and the results were compared with TCT and histological examination.Examination the positive which TCT,h -TERC and c -myc by pathological examination.The final diag-nosis was determined by the pathological examination.Results TCT was abnormal in 26.4% of 500 case,18.0%abnormal h -TERC gene,16.0% abnormal c -myc gene.In 270 cases according to the cervical biopsy,the positive rate of chronic inflammation,cervical intraepithelial neoplasia (CIN)Ⅰ,CINⅡ,CINⅢ and cervical cancer:44.4%, 38.2%,36.4%,18.2%,and 7.3% respectively.The positive rates of h -TERC were 18.1%,45.4%,52.5%, 65.9% and 100.0%,respectively.The positive rates of c -myc were 21.4%,48.9%,56.7%,59.9% and 100.0%.With increased pathological grade,the expressions of h -TERC and c -myc were high.Conclusion TCT combined with h -TERC and c -myc can test cervical cancer more effective.%目的:探讨阴道脱落细胞检查(TCT)结合人类染色体末端酶基因(h-TERC)和 c-myc 检测在宫颈癌中的价值。方法运用免疫荧光原位杂交技术检测近三年来该院宫颈癌患者500例的宫颈脱落细胞中h-TERC 和 c-myc 的表达,将其检测结果与 TCT 检测结果比较,将上述三种结果的任一阳性检测再进行病理学诊断标准来确定,且以病理诊断为准进行分析。结果在所检测的500例患者中,TCT 异常者132例(26.4%),h-TECR 异常者90例(18.0%),c-myc 异常者80例(16.0%),将270例患者进行阴道宫颈活检技术,在这些病例中,宫颈慢性炎者120例,宫颈病变者150例,其中宫颈上皮瘤变 CINⅠ52例(38.2%),CINⅡ50例(36.4%),CIN Ⅲ30例(18.2%),宫颈癌18例(7.3%)。在所检测的病例中,

  4. NM23-H2 may play an indirect role in transcriptional activation of c-myc gene expression but does not cleave the nuclease hypersensitive element III[subscript 1

    Energy Technology Data Exchange (ETDEWEB)

    Dexheimer, Thomas S.; Carey, Steven S.; Zuohe, Song; Gokhale, Vijay M.; Hu, Xiaohui; Murata, Lauren B.; Maes, Estelle M.; Weichsel, Andrzej; Sun, Daekyu; Meuillet, Emmanuelle J.; Montfort, William R.; Hurley, Laurence H. (Ariz)

    2009-05-13

    The formation of G-quadruplex structures within the nuclease hypersensitive element (NHE) III{sub 1} region of the c-myc promoter and the ability of these structures to repress c-myc transcription have been well established. However, just how these extremely stable DNA secondary structures are transformed to activate c-myc transcription is still unknown. NM23-H2/nucleoside diphosphate kinase B has been recognized as an activator of c-myc transcription via interactions with the NHE III{sub 1} region of the c-myc gene promoter. Through the use of RNA interference, we confirmed the transcriptional regulatory role of NM23-H2. In addition, we find that further purification of NM23-H2 results in loss of the previously identified DNA strand cleavage activity, but retention of its DNA binding activity. NM23-H2 binds to both single-stranded guanine- and cytosine-rich strands of the c-myc NHE III{sub 1} and, to a lesser extent, to a random single-stranded DNA template. However, it does not bind to or cleave the NHE III{sub 1} in duplex form. Significantly, potassium ions and compounds that stabilize the G-quadruplex and i-motif structures have an inhibitory effect on NM23-H2 DNA-binding activity. Mutation of Arg{sup 88} to Ala{sup 88} (R88A) reduced both DNA and nucleotide binding but had minimal effect on the NM23-H2 crystal structure. On the basis of these data and molecular modeling studies, we have proposed a stepwise trapping-out of the NHE III{sub 1} region in a single-stranded form, thus allowing single-stranded transcription factors to bind and activate c-myc transcription. Furthermore, this model provides a rationale for how the stabilization of the G-quadruplex or i-motif structures formed within the c-myc gene promoter region can inhibit NM23-H2 from activating c-myc gene expression.

  5. The antihistamines clemastine and desloratadine inhibit STAT3 and c-Myc activities and induce apoptosis in cutaneous T-cell lymphoma cell lines.

    Science.gov (United States)

    Döbbeling, Udo; Waeckerle-Men, Ying; Zabel, Franziska; Graf, Nicole; Kündig, Thomas M; Johansen, Pål

    2013-02-01

    Mycosis fungoides and its leukaemic counterpart Sézary syndrome are the most frequent cutaneous T-cell lymphomas (CTCL), and there is no cure for these diseases. We evaluated the effect of clinically approved antihistamines on the growth of CTCL cell lines. CTCL cell lines as well as blood lymphocytes from patients with Sézary syndrome were cultured with antihistamines, and the cell were analysed for proliferation, apoptosis and expression of programmed death molecules and transcription factors. The two antihistamines clemastine and desloratadine, currently used for symptom alleviation in allergy, induced potent reduction of the activities of the constitutively active transcription factors c-Myc, STAT3, STAT5a and STAT5b in mycosis fungoides and Sézary syndrome cell lines. This inhibition was followed by apoptosis and cell death, especially in the Sézary syndrome-derived cell line Hut78 that also showed increased expression of the programmed death-1 (PD-1) after clemastine treatment. In lymphocytes isolated from Sézary syndrome patients, the CD4-positive fraction underwent apoptosis after clemastine treatment, while CD4-negative lymphocytes were little affected. Because both c-Myc and STAT transcription factors are highly expressed in proliferating tumours, their inhibition by clemastine, desloratadine and other inhibitors could complement established chemotherapies not only for cutaneous T-cell lymphomas but perhaps also other cancers.

  6. Phospholipase D1 Couples CD4+ T Cell Activation to c-Myc-Dependent Deoxyribonucleotide Pool Expansion and HIV-1 Replication.

    Directory of Open Access Journals (Sweden)

    Harry E Taylor

    2015-05-01

    Full Text Available Quiescent CD4+ T cells restrict human immunodeficiency virus type 1 (HIV-1 infection at early steps of virus replication. Low levels of both deoxyribonucleotide triphosphates (dNTPs and the biosynthetic enzymes required for their de novo synthesis provide one barrier to infection. CD4+ T cell activation induces metabolic reprogramming that reverses this block and facilitates HIV-1 replication. Here, we show that phospholipase D1 (PLD1 links T cell activation signals to increased HIV-1 permissivity by triggering a c-Myc-dependent transcriptional program that coordinates glucose uptake and nucleotide biosynthesis. Decreasing PLD1 activity pharmacologically or by RNA interference diminished c-Myc-dependent expression during T cell activation at the RNA and protein levels. PLD1 inhibition of HIV-1 infection was partially rescued by adding exogenous deoxyribonucleosides that bypass the need for de novo dNTP synthesis. Moreover, the data indicate that low dNTP levels that impact HIV-1 restriction involve decreased synthesis, and not only increased catabolism of these nucleotides. These findings uncover a unique mechanism of action for PLD1 inhibitors and support their further development as part of a therapeutic combination for HIV-1 and other viral infections dependent on host nucleotide biosynthesis.

  7. Nuclear localization of vascular endothelial growth factor-D and regulation of c-Myc-dependent transcripts in human lung fibroblasts.

    Science.gov (United States)

    El-Chemaly, Souheil; Pacheco-Rodriguez, Gustavo; Malide, Daniela; Meza-Carmen, Victor; Kato, Jiro; Cui, Ye; Padilla, Philip I; Samidurai, Arun; Gochuico, Bernadette R; Moss, Joel

    2014-07-01

    Lymphangiogenesis and angiogenesis are processes that are, in part, regulated by vascular endothelial growth factor (VEGF)-D. The formation of lymphatic structures has been implicated in multiple lung diseases, including pulmonary fibrosis. VEGF-D is a secreted protein produced by fibroblasts and macrophages, which induces lymphangiogenesis by signaling via VEGF receptor-3, and angiogenesis through VEGF receptor-2. VEGF-D contains a central VEGF homology domain, which is the biologically active domain, with flanking N- and C-terminal propeptides. Full-length VEGF-D (∼ 50 kD) is proteolytically processed in the extracellular space, to generate VEGF homology domain that contains the VEGF-D receptor-binding sites. Here, we report that, independent of its cell surface receptors, full-length VEGF-D accumulated in nuclei of fibroblasts, and that this process appears to increase with cell density. In nuclei, full-length VEGF-D associated with RNA polymerase II and c-Myc. In cells depleted of VEGF-D, the transcriptionally regulated genes appear to be modulated by c-Myc. These findings have potential clinical implications, as VEGF-D was found in fibroblast nuclei in idiopathic pulmonary fibrosis, a disease characterized by fibroblast proliferation. These findings are consistent with actions of full-length VEGF-D in cellular homeostasis in health and disease, independent of its receptors.

  8. ALK and c-myc gene of anaplastic large cell lymphoma%间变性大细胞淋巴瘤的ALK和c-myc基因研究

    Institute of Scientific and Technical Information of China (English)

    于冉; 周春菊; 陈刚; 高子芬; 时云飞; 石岩; 谢建兰; 周小鸽; 宫丽平

    2010-01-01

    目的 探讨间变性大细胞淋巴瘤(ALCL)中间变性淋巴瘤激酶(ALK)基因与c-myc基因的分子遗传学改变.方法 收集原发系统性ALCL石蜡包埋组织标本72例,利用间期荧光原位杂交(FISH)技术检测ALCL肿瘤组织中ALK和c-myc基因结构与数目的变化.结果 72例ALCL中,ALK阳性者42例,40例存在涉及ALK基因的染色体易位,其中17例同时伴有ALK基因的多拷贝;ALK阴性的30例均未发现ALK基因的易位,但其中14例存在ALK基因的多拷贝.ALK基因多拷贝的发生率在ALK阳性与阴性组中的差异无统计学意义(P>0.05).72例病例中,均未发现涉及c-myc基因的染色体易位,但其中24例存在c-myc基因的多拷贝.结论 大部分ALCL伴有ALK基因的异常(75.0%).以涉及ALK基因的染色体易位最为多见(55.6%),ALK基因多拷贝也是ALCL较为常见的遗传学改变(43.1%).前者只出现于ALK阳性ALCL中,后者既可出现在ALK阳性也可出现在ALK阴性的ALCL中.ALCL中不见或罕见涉及c-myc基因的染色体易位,但c-myc基因多拷贝的现象较为常见(33.3%).%Objective To investigate the molecular genetic changes of anaplastic lymphoma kinase (ALK) gene and c-myc gene in anaplastic large cell lymphoma (ALCL). Methods The structural aberrations and changes of copy numbers in ALK and c-myc genes in 72 paraffin-embedded ALCL specimens were detected by interphase fluorescence in situ hybridization (FISH). Results Among 72 ALCL specimens, ALK protein was expressed in 42, ALK gene translocation was detected in 40 specimens in which extra copies of ALK gene were detected in 17. ALK gene translocation was not found in all 30 ALK negative specimens, but extra copies of ALK gene were detected in 14 cases. The difference of incidence rates of extra copies in ALK gene between ALK positive and ALK negative specimens was not significant (P>0.05). c-myc gene translocation was not found in any of 72 ALCL specimens, but extra copies were detected in 24

  9. Expressão dos protooncogenes c-fos, c-myc e c-jun em miométrio normal e mioma humanos Expression of the protooncogenes c-fos, c-myc and c-jun in human normal miometrium and leiomyoma

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    Ana Luiza Ferrari

    2006-10-01

    Full Text Available OBJETIVO: Comparar a expressão gênica (mRNA e protéica dos protooncogenes c-fos, c-myc e c-jun em miométrio normal e mioma humanos. MÉTODOS: Foi realizado um estudo do tipo caso-controle. O material foi coletado de 12 pacientes submetidas a histerectomia no Hospital de Clínicas de Porto Alegre. A expressão do mRNA específico para c-myc, c-fos, c-jun e beta-microglobulina foi avaliada pela técnica de RT-PCR, utilizando primers específicos para cada gene. A expressão protéica destes protooncogenes foi avaliada através de Western blot com anticorpos específicos. RESULTADOS: Não houve diferença significativa para expressão gênica desses protooncogenes entre miométrio normal e mioma (c-myc: 0,87 ± 0,08 vs 0,87 ± 0,08, p = 0,952; c-fos: 1,10 ± 0,17 vs 1,01 ± 0,11, p = 0,21; c-jun: 1,03 ± 0,12 vs 0,96 ± 0,09, p = 0,168, respectivamente. Não houve diferença significativa para expressão protéica desses protooncogenes entre miométrio normal e mioma (c-myc: 1,36 ± 0,48 vs 1,53 ± 0,29, p = 0,569; c-fos: 8,85 ± 5,5 vs 6,56 ± 4,22, p = 0,434; e c-jun: 6,47 ± 3,04 vs 5,42 ± 2,03, p = 0,266, respectivamente. CONCLUSÃO: A expressão gênica (transcrição e a expressão protéica (tradução dos protooncogenes c-myc, c-fos e c-jun em mioma e miométrio normal são semelhantes.Uterine myomas are common benign tumors of the female genital tract. The expression of growth factor signal transduction cascade components including the protooncogenes c-myc, c-fos, and c-jun seem to be involved in the development of myomas. PURPOSE: To compare the gene (mRNA and protein expression of the protooncogenes c-fos, c-myc, and c-jun in human normal myometrium and leiomyoma. METHOD: A case-control study was performed. Samples were collected from 12 patients submitted to hysterectomy at the Hospital de Clínicas at Porto Alegre. The expression of the specific mRNA for c-myc, c-fos, c-jun, and beta-microglobulin was assessed through the RT

  10. Incidence of HPV Infection in Oral Squamous Cell Carcinoma and Its Association with the Presence of p53 & c-myc Mutation : A Case Control Study in Muwardi Hospital Surakarta

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    Adi Prayitno

    2012-12-01

    Full Text Available Introduction: Annual incidence rates for oral and pharyngeal cancer are estimated at 25 cases per 100,000 in developing countries. Human papilloma virus (HPV was implicated in pathogenesis of Cancer. The mutations of p53 and c-myc are found 50% in cancer. Objective: Aims of this research were to know the incidence of OSSC patient which realized HPV infection without p53 and c-myc gene mutation. Materials and Methods: Tissue biopsy frozen sections were taken from BOSC (Benign Oral Squamous Cell and OSCC (Oral Squamous Cell Carcinoma patients collected from Oral and Dental Departement of dr Muwardi Distric Hospital in Surakarta from January 2007 to January 2008. To amplify L1-HPV gene for fixed the HPV stressor. To amplify p53 and c-myc genes, continued with SSCP (Single Strand Conformational Polymorphisme analysis and followed with measurement using densitometer, to see mutation existence. The collected data were analyzed with Chi Square. Results: BOSC patient identified 23% with HPV infections and OSCC patient identified 73% with HPV infections. Hundred percent BOSC patient with HPV infection without mutation in p53 gene and c-myc gene, 81% OSCC patient with HPV infection without mutation in p53 gene and 91% OSCC patient with HPV infection without mutation in c-myc gene. Chi  square analysis showed significant difference between BOSC and OSCC patients with HPV infection without mutation in p53 and c-myc gene. Conclusion: HPV is a factor for pathogenesis of OSCC.DOI: 10.14693/jdi.v17i2.44

  11. Cyclin D1 inhibits whereas c-Myc enhances the cytotoxicity of cisplatin in mouse pancreatic cancer cells via regulation of several members of the NF-κB and Bcl-2 families

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    Ayman El-Kady

    2011-01-01

    Full Text Available Background: Cisplatin (CDDP is a drug used for treatment of many types of malignancy but pancreatic cancer is relatively resistant to it. This study aims to determine whether and how cyclin D1 (D1 and c-Myc influence the response of pancreatic cancer cells to CDDP. Materials and Methods: Ela-mycPT mouse pancreatic cancer cells were transfected with D1 or c-myc cDNA and treated with CDDP alone or together with NPCD, an inhibitor of cyclin dependent ckinase (CDK 4 and 6. Reverse transcription followed by polymerase chain reaction (RT-PCR and western blot assays were used to determine the mRNA and protein levels of interested genes. Cell viability was determined using 3-(4, 5-Dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide (MTT assay. Results: Treatment of Ela-mycPT1 cells with CDDP caused an increase in c-myc expression but a slightly latent decrease in D1 expression, whereas D1 and c-Myc proteins repressed each other. D1 or c-Myc rendered Ela-mycPT1 cells resistant or sensitive, respectively, to CDDP. D1 induced the expression of several members of the NF-κB family, including RelA, RelB, Nfκb1 and Nfκb2. D1 also induced BIRC5 and several pro-survival members of the Bcl-2 gene family, including Bcl-2, Mcl-1 and Bad while it decreased the level of the pro-apoptotic Noxa. Inhibition of CDK4 or CDK6 kinase activity by NPCD did not affect these effects of D1. In contrast, c-Myc in Ela-mycPT1 and Ela-mycPT4 cells has the opposite effects to D1 on the expression of most of these apoptosis regulating genes. Conclusion: Our results suggest that induction of c-Myc and inhibition of D1 may be mechanisms for CDDP to elicit cytotoxicity. On the other hand, D1 induces whereas c-Myc represses the expression of key NF-κB family members to induce and repress, respectively, the expression of BIRC5 and several Bcl-2 family members, in turn inhibiting or enhancing the response to CDDP.

  12. Genetic dissimilarity between primary colorectal carcinomas and their lymph node metastases: ploidy, p53, bcl-2, and c-myc expression--a pilot study.

    Science.gov (United States)

    Zalata, Khaled Refaat; Elshal, Mohamed Farouk; Foda, Abd AlRahman Mohammad; Shoma, Ashraf

    2015-08-01

    The current paradigm of metastasis proposes that rare cells within primary tumors acquire metastatic capability via sequential mutations, suggesting that metastases are genetically dissimilar from their primary tumors. This study investigated the changes in the level of expression of a well-defined panel of cell proliferation, differentiation, and apoptosis markers between the primary colorectal cancer (CRC) and the corresponding synchronous lymph node (LN) metastasis from the same patients. DNA flow cytometry and immunostaining of p53, bcl-2, and c-myc were carried out on 36 cases of CRC radical resection specimens with their corresponding LN metastases. There was very low probability that the histological patterns of primary tumors and LN metastases are independent (p < 0.001). Metastatic tumors were significantly more diffusely positive for p53 than the primary tumors (p < 0.001). Conversely, primary tumors were significantly more diffusely positive for c-myc than metastatic tumors (p = 0.011). No significant difference was found between the LNs and the primary tumors in bcl-2 positivity (p = 0.538) and DNA aneuploidy (p = 0.35), with a tendency towards negative bcl-2 and less aneuploidy in LN metastases than primary tumors. In conclusion, LN metastatic colorectal carcinomas have a tendency of being less differentiated, with a higher incidence of diffuse p53 staining, lower incidence of bcl-2 staining, and less aneuploidy in comparison to their primary counterparts suggesting a more aggressive biological behavior, which could indicate the necessity for more aggressive adjuvant therapy.

  13. Disturbance of Bcl-2, Bax, Caspase-3, Ki-67 and C-myc expression in acute and subchronic exposure to benzo(a)pyrene in cervix.

    Science.gov (United States)

    Gao, Meili; Li, Yongfei; Ji, Xiaoying; Xue, Xiaochang; Chen, Lan; Feng, Guodong; Zhang, Huqin; Wang, Huichun; Shah, Walayat; Hou, Zhanwu; Kong, Yu

    2016-03-01

    Epidemiological studies have demonstrated that cigarette smoking is an important cofactor or an independent risk factor for the development of cervical cancer. Benzo(a)pyrene (BaP) is one of the most potent tobacco smoke carcinogens in tobacco smoke. BaP induced DNA damage and over expression in p53 cervical tissue of mice as demonstrated in our previous study. Here we present the findings of exposure to BaP on the expression of Bcl-2, C-myc, Ki-67, Caspase-3 and Bax genes in mouse cervix. Acute intraperitoneal administration of BaP (12.5, 25, 50, 100mg/kg body weight) to ICR female mice induced a significant increase in Bcl-2, C-myc, Ki-67 mRNA and protein level till 72h except in Bcl-2 at 24h with 12.5, 25, 50mg/kg as well as at 48h with 12.5mg/kg body weight post treatment. A significant increase was also seen in Caspase-3 and Bax mRNA and protein level with peak level at 24h and gradual decrease till 72h, however, the expression of caspase-3 increased while that of Bax decreased with increasing dose of Bap after 24h. In sub chronic intraperitoneal and oral gavage administration of BaP (2.5, 5, 10mg/kg body weight), similar significant increase was observed for all the examined genes as compared to the control and vehicle groups, however the expression of Bax decreased in a dose dependent manner. The findings of this study will help in further understanding the molecular mechanism of BaP induced carcinogenesis of cervical cancer.

  14. PET/CT imaging of c-Myc transgenic mice identifies the genotoxic N-nitroso-diethylamine as carcinogen in a short-term cancer bioassay.

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    Katja Hueper

    Full Text Available BACKGROUND: More than 100,000 chemicals are in use but have not been tested for their safety. To overcome limitations in the cancer bioassay several alternative testing strategies are explored. The inability to monitor non-invasively onset and progression of disease limits, however, the value of current testing strategies. Here, we report the application of in vivo imaging to a c-Myc transgenic mouse model of liver cancer for the development of a short-term cancer bioassay. METHODOLOGY/PRINCIPAL FINDINGS: μCT and ¹⁸F-FDG μPET were used to detect and quantify tumor lesions after treatment with the genotoxic carcinogen NDEA, the tumor promoting agent BHT or the hepatotoxin paracetamol. Tumor growth was investigated between the ages of 4 to 8.5 months and contrast-enhanced μCT imaging detected liver lesions as well as metastatic spread with high sensitivity and accuracy as confirmed by histopathology. Significant differences in the onset of tumor growth, tumor load and glucose metabolism were observed when the NDEA treatment group was compared with any of the other treatment groups. NDEA treatment of c-Myc transgenic mice significantly accelerated tumor growth and caused metastatic spread of HCC in to lung but this treatment also induced primary lung cancer growth. In contrast, BHT and paracetamol did not promote hepatocarcinogenesis. CONCLUSIONS/SIGNIFICANCE: The present study evidences the accuracy of in vivo imaging in defining tumor growth, tumor load, lesion number and metastatic spread. Consequently, the application of in vivo imaging techniques to transgenic animal models may possibly enable short-term cancer bioassays to significantly improve hazard identification and follow-up examinations of different organs by non-invasive methods.

  15. c-Myc Alters Substrate Utilization and O-GlcNAc Protein Posttranslational Modifications without Altering Cardiac Function during Early Aortic Constriction.

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    Dolena Ledee

    Full Text Available Hypertrophic stimuli cause transcription of the proto-oncogene c-Myc (Myc. Prior work showed that myocardial knockout of c-Myc (Myc attenuated hypertrophy and decreased expression of metabolic genes after aortic constriction. Accordingly, we assessed the interplay between Myc, substrate oxidation and cardiac function during early pressure overload hypertrophy. Mice with cardiac specific, inducible Myc knockout (MycKO-TAC and non-transgenic littermates (Cont-TAC were subjected to transverse aortic constriction (TAC; n = 7/group. Additional groups underwent sham surgery (Cont-Sham and MycKO-Sham, n = 5 per group. After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketone bodies and unlabeled glucose and insulin. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. In sham hearts, Myc knockout did not affect cardiac function or substrate preferences for the citric acid cycle. However, Myc knockout altered fractional contributions during TAC. The unlabeled fractional contribution increased in MycKO-TAC versus Cont-TAC, whereas ketone and free fatty acid fractional contributions decreased. Additionally, protein posttranslational modifications by O-GlcNAc were significantly greater in Cont-TAC versus both Cont-Sham and MycKO-TAC. In conclusion, Myc alters substrate preferences for the citric acid cycle during early pressure overload hypertrophy without negatively affecting cardiac function. Myc also affects protein posttranslational modifications by O-GlcNAc during hypertrophy, which may regulate Myc-induced metabolic changes.

  16. Protein kinase A antagonist inhibits β-catenin nuclear translocation, c-Myc and COX-2 expression and tumor promotion in ApcMin/+ mice

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    Brudvik Kristoffer W

    2011-12-01

    Full Text Available Abstract Background The adenomatous polyposis coli (APC protein is part of the destruction complex controlling proteosomal degradation of β-catenin and limiting its nuclear translocation, which is thought to play a gate-keeping role in colorectal cancer. The destruction complex is inhibited by Wnt-Frz and prostaglandin E2 (PGE2 - PI-3 kinase pathways. Recent reports show that PGE2-induced phosphorylation of β-catenin by protein kinase A (PKA increases nuclear translocation indicating two mechanisms of action of PGE2 on β-catenin homeostasis. Findings Treatment of ApcMin/+ mice that spontaneously develop intestinal adenomas with a PKA antagonist (Rp-8-Br-cAMPS selectively targeting only the latter pathway reduced tumor load, but not the number of adenomas. Immunohistochemical characterization of intestines from treated and control animals revealed that expression of β-catenin, β-catenin nuclear translocation and expression of the β-catenin target genes c-Myc and COX-2 were significantly down-regulated upon Rp-8-Br-cAMPS treatment. Parallel experiments in a human colon cancer cell line (HCT116 revealed that Rp-8-Br-cAMPS blocked PGE2-induced β-catenin phosphorylation and c-Myc upregulation. Conclusion Based on our findings we suggest that PGE2 act through PKA to promote β-catenin nuclear translocation and tumor development in ApcMin/+ mice in vivo, indicating that the direct regulatory effect of PKA on β-catenin nuclear translocation is operative in intestinal cancer.

  17. Oridonin induces apoptosis and senescence in colorectal cancer cells by increasing histone hyperacetylation and regulation of p16, p21, p27 and c-myc

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    Zhao Ying-Zheng

    2010-11-01

    Full Text Available Abstract Background Oridonin, a tetracycline diterpenoid compound, has the potential antitumor activities. Here, we evaluate the antitumor activity and action mechanisms of oridonin in colorectal cancer. Methods Effects of oridonin on cell proliferation were determined by using a CCK-8 Kit. Cell cycle distribution was determined by flow cytometry. Apoptosis was examined by analyzing subdiploid population and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Senescent cells were determined by senescence-associated β-galactosidase activity analysis. Semi-quantitative RT-PCR was used to examine the changes of mRNA of p16, p21, p27 and c-myc. The concomitant changes of protein expression were analyzed with Western blot. Expression of AcH3 and AcH4 were examined by immunofluorescence staining and Western blots. Effects of oridonin on colony formation of SW1116 were examined by Soft Agar assay. The in vivo efficacy of oridonin was detected using a xenograft colorectal cancer model in nude mice. Results Oridonin induced potent growth inhibition, cell cycle arrest, apoptosis, senescence and colony-forming inhibition in three colorectal cancer cell lines in a dose-dependent manner in vitro. Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice. With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4 hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression. Conclusion Oridonin possesses potent in vitro and in vivo anti-colorectal cancer activities that correlated with induction of histone hyperacetylation and regulation of pathways critical for maintaining growth inhibition and cell cycle arrest. Therefore, oridonin may represent a novel therapeutic option in colorectal cancer treatment.

  18. Alterations in TP53, cyclin D2, c-Myc, p21WAF1/CIP1 and p27KIP1 expression associated with progression in B-CLL

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    Antosz Halina

    2010-04-01

    Full Text Available B-cell chronic lymphocytic leukaemia (B-CLL originates from B lymphocytes that may differ in the activationlevel, maturation state or cellular subgroups in peripheral blood. Tumour progression in CLL B cells seems to result in gradualaccumulation of the clone of resting B lymphocytes in the early phases (G0/G1 of the cell cycle. The G1 phase isimpaired in B-CLL. We investigated the gene expression of five key cell cycle regulators: TP 53, c-Myc, cyclin D2,p21WAF1/CIP1 and p27KIP1, which primarily regulate the G1 phase of the cell cycle, or S-phase entry and ultimately controlthe proliferation and cell growth as well as their role in B-CLL progression. The study was conducted in peripheral bloodCLL lymphocytes of 40 previously untreated patients. Statistical analysis of correlations of TP53, cyclin D2, c-Myc,p21WAF1/CIP1 and p27KIP1 expressions in B-CLL patients with different Rai stages demonstrated that the progression of diseasewas accompanied by increases in p53, cyclin D2 and c-Myc mRNA expression. The expression of p27KIP1 was nearlystatistically significant whereas that of p21 WAF1/CIP1 showed no such correlation. Moreover, high expression levels of TP53and c-Myc genes were found to be closely associated with more aggressive forms of the disease requiring earlier therapy.

  19. Microwave-assisted synthesis of cupric (Ⅱ) complex with porphyrin and its interaction with c-myc G4 DNA%微波辅助四(P-甲氧苯基)卟啉铜(Ⅱ)的合成及其与c-myc G4 DNA的相互作用

    Institute of Scientific and Technical Information of China (English)

    孙福强; 梅文杰; 吴韦黎; 吴剑; 张召; 张紫伊; 崔英德

    2014-01-01

    以吡咯、p-甲氧基苯甲醛为原料,丙酸为溶剂,130℃条件下制得四(p-甲氧苯基)卟啉(TMOPP);然后在100℃微波辐射条件下,以TMOPP和乙酸铜为原料,DMF为溶剂,制得目标化合物四(p-甲氧苯基)卟啉铜(Ⅱ)配合物(CuTMOPP).采用电喷雾质谱、紫外光谱和红外光谱等分析方法对所合成的目标化合物进行了表征,目标化合物的理论值和实验值基本一致.进一步采用紫外光谱、CD光谱、FRET熔点实验、PCR-Stop实验考察了目标化合物与c-myc G4 DNA的相互作用,结果表明目标化合物可能与c-myc G4 DNA以静电方式结合,从而抑制其复制,进一步对其生物功能的影响还在研究中.

  20. Identification of cytotoxic drugs that selectively target tumor cells with MYC overexpression.

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    Anna Frenzel

    Full Text Available Expression of MYC is deregulated in a wide range of human cancers, and is often associated with aggressive disease and poorly differentiated tumor cells. Identification of compounds with selectivity for cells overexpressing MYC would hence be beneficial for the treatment of these tumors. For this purpose we used cell lines with conditional MYCN or c-MYC expression, to screen a library of 80 conventional cytotoxic compounds for their ability to reduce tumor cell viability and/or growth in a MYC dependent way. We found that 25% of the studied compounds induced apoptosis and/or inhibited proliferation in a MYC-specific manner. The activities of the majority of these were enhanced both by c-MYC or MYCN over-expression. Interestingly, these compounds were acting on distinct cellular targets, including microtubules (paclitaxel, podophyllotoxin, vinblastine and topoisomerases (10-hydroxycamptothecin, camptothecin, daunorubicin, doxorubicin, etoposide as well as DNA, RNA and protein synthesis and turnover (anisomycin, aphidicholin, gliotoxin, MG132, methotrexate, mitomycin C. Our data indicate that MYC overexpression sensitizes cells to disruption of specific pathways and that in most cases c-MYC and MYCN overexpression have similar effects on the responses to cytotoxic compounds. Treatment of the cells with topoisomerase I inhibitors led to down-regulation of MYC protein levels, while doxorubicin and the small molecule MYRA-A was found to disrupt MYC-Max interaction. We conclude that the MYC pathway is only targeted by a subset of conventional cytotoxic drugs currently used in the clinic. Elucidating the mechanisms underlying their specificity towards MYC may be of importance for optimizing treatment of tumors with MYC deregulation. Our data also underscores that MYC is an attractive target for novel therapies and that cellular screenings of chemical libraries can be a powerful tool for identifying compounds with a desired biological activity.

  1. Identification of cytotoxic drugs that selectively target tumor cells with MYC overexpression.

    Science.gov (United States)

    Frenzel, Anna; Zirath, Hanna; Vita, Marina; Albihn, Ami; Henriksson, Marie Arsenian

    2011-01-01

    Expression of MYC is deregulated in a wide range of human cancers, and is often associated with aggressive disease and poorly differentiated tumor cells. Identification of compounds with selectivity for cells overexpressing MYC would hence be beneficial for the treatment of these tumors. For this purpose we used cell lines with conditional MYCN or c-MYC expression, to screen a library of 80 conventional cytotoxic compounds for their ability to reduce tumor cell viability and/or growth in a MYC dependent way. We found that 25% of the studied compounds induced apoptosis and/or inhibited proliferation in a MYC-specific manner. The activities of the majority of these were enhanced both by c-MYC or MYCN over-expression. Interestingly, these compounds were acting on distinct cellular targets, including microtubules (paclitaxel, podophyllotoxin, vinblastine) and topoisomerases (10-hydroxycamptothecin, camptothecin, daunorubicin, doxorubicin, etoposide) as well as DNA, RNA and protein synthesis and turnover (anisomycin, aphidicholin, gliotoxin, MG132, methotrexate, mitomycin C). Our data indicate that MYC overexpression sensitizes cells to disruption of specific pathways and that in most cases c-MYC and MYCN overexpression have similar effects on the responses to cytotoxic compounds. Treatment of the cells with topoisomerase I inhibitors led to down-regulation of MYC protein levels, while doxorubicin and the small molecule MYRA-A was found to disrupt MYC-Max interaction. We conclude that the MYC pathway is only targeted by a subset of conventional cytotoxic drugs currently used in the clinic. Elucidating the mechanisms underlying their specificity towards MYC may be of importance for optimizing treatment of tumors with MYC deregulation. Our data also underscores that MYC is an attractive target for novel therapies and that cellular screenings of chemical libraries can be a powerful tool for identifying compounds with a desired biological activity.

  2. Thermo-Responsive Complexes of c-Myc Antisense Oligonucleotide with Block Copolymer of Poly(OEGMA) and Quaternized Poly(4-Vinylpyridine).

    Science.gov (United States)

    Topuzogullari, Murat; Elalmis, Yeliz Basaran; Isoglu, Sevil Dincer

    2017-04-01

    Solution behavior of thermo-responsive polymers and their complexes with biological macromolecules may be affected by environmental conditions, such as the concentration of macromolecular components, pH, ion concentration, etc. Therefore, a thermo-responsive polymer and its complexes should be characterized in detail to observe their responses against possible environments under physiological conditions before biological applications. To briefly indicate this important issue, thermo-responsive block copolymer of quaternized poly(4-vinylpyridine) and poly(oligoethyleneglycol methyl ether methacrylate) as a potential nonviral vector has been synthesized. Polyelectrolyte complexes of this copolymer with the antisense oligonucleotide of c-Myc oncogene are also thermo-responsive but, have lower LCST (lower critical solution temperature) values compared to individual copolymer. LCST values of complexes decrease with molar ratio of macromolecular components and presence of salt. Dilution of solutions also affects solution behavior of complexes and causes a significant decrease in size and an increase in LCST, which indicates possible effects of severe dilutions in the blood stream.

  3. Melatonin promotes circadian rhythm-induced proliferation through Clock/histone deacetylase 3/c-Myc interaction in mouse adipose tissue.

    Science.gov (United States)

    Liu, Zhenjiang; Gan, Lu; Luo, Dan; Sun, Chao

    2017-05-01

    Melatonin is synthesized in the pineal gland and controls circadian rhythm of peripheral adipose tissue, resulting in changes in body weight. Although core regulatory components of clock rhythmicity have been defined, insight into the mechanisms of circadian rhythm-mediated proliferation in adipose tissue is still limited. Here, we showed that melatonin (20 mg/kg/d) promoted circadian and proliferation processes in white adipose tissue. The circadian amplitudes of brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (Bmal1, Pcircadian locomotor output cycles kaput (Clock, Pcycle and increased cell numbers (Pcircadian disruption and promoted adipocyte proliferation in chronic jet-lagged mice and obese mice. Thus, our study found that melatonin promoted adipocyte proliferation by forming a Clock/HDAC3/c-Myc complex and subsequently driving the circadian amplitudes of proliferation genes. Our data reveal a novel mechanism that links circadian rhythm to cell proliferation in adipose tissue. These findings also identify a new potential means for melatonin to prevent and treat sleep deprivation-caused obesity.

  4. Radiosensitivity of small-cell lung cancer xenografts compared with activity of c-myc, N-myc, L-myc, c-raf-1 and K-ras proto-oncogenes

    DEFF Research Database (Denmark)

    Rygaard, K; Slebos, R J; Spang-Thomsen, M

    1991-01-01

    , the CPH and the GLC series. CPH-54A and CPH-54B are in vitro-derived subclones of a SCLC cell line, while the GLC tumours were established as cell lines from a patient during longitudinal follow-up. Both tumours were later transferred into nude mice. CPH-54A was more sensitive to single-dose irradiation...... than CPH-54B, while, with respect to the 3 GLC tumours examined, GLC-16 was most sensitive, followed by GLC-14 and GLC-19. The CPH tumours expressed similar amounts of c-myc and c-raf-1 mRNA, and neither expressed N-myc or L-myc. GLC-14 expressed N-myc and c-raf-1 mRNA but no c-myc. GLC-16 and GLC-19...

  5. 原癌基因c-myc真核表达载体构建及其生物学作用%Construction and identification of an original oncogene c-myc eukaryotic expression vector

    Institute of Scientific and Technical Information of China (English)

    荆志波; 韦丹丹; 逄越

    2013-01-01

    目的 利用基因工程技术构建携带原癌基因c-myc的真核表达载体pIRES2-AcGFPl-Nuc-c-myc重组质粒并在Hela细胞中表达.方法 以构建好的表达质粒pET28a-c-myc为基础,利用PCR方法扩增c-myc基因,并加入EcoR Ⅰ和SmaⅠ酶切位点,克隆至pMD 19-T Simple载体,双酶切后将其与同样经过双酶切的真核表达载体pIRES2-AcGFP1-Nuc连接,通过PCR、酶切及测序鉴定重组质粒的正确性,再将重组质粒pIRES2-AcGFPl-Nuc-c-myc转染Hela细胞,利用荧光显微镜观察GFP表达,利用MTT和免疫印迹证实c-myc蛋白表达量提高.结果 经PCR和酶切鉴定与预期结果相符,测序结果与GenBank中报道的序列完全一致,成功构建了重组表达质粒.免疫印迹证实c-myc基因在Hela细胞中得到表达.MTT结果显示Hela细胞数量显著增加.结论 真核表达载体pIRES2-AcGFP 1-Nuc-c-myc成功构建,c-myc基因在Hela细胞中成功表达,具有生物学活性.%This study designed to construct and express original oncogene c-myc eukaryotic expression vector pIRES2-AcGFP1-Nuc-c-myc using gene engineering technique.The c-myc gene was obtained by PCR amplification from pET28a-c-myc,to constructed pIRES2-AcGFPl-Nuc eukaryotic expression vector,which was then confirmed by PCR method,restriction analysis and DNA sequencing.In addition,the recombinant plasmid pIRES2-AcGFPl-Nuc-c-myc was transfected to Hela cells,and green fluorescent protein was expressed successfully under fluorescence microscopy.Analysis of Western blotting showed that c-myc protein expression was increased in Hela cell,and MTT assay indicated c-myc protein could promote the proliferation of Hela cells.In conclusion,eukaryotic expression vector of c-myc gene was constructed and transfected,which lay foundation for the lamprey cell line research.

  6. Stabilization of c-myc G-Quadruplex DNA, inhibition of telomerase activity, disruption of mitochondrial functions and tumor cell apoptosis by platinum(II) complex with 9-amino-oxoisoaporphine.

    Science.gov (United States)

    Qin, Jiao-Lan; Qin, Qi-Pin; Wei, Zu-Zhuang; Yu, Yan-Cheng; Meng, Ting; Wu, Chen-Xuan; Liang, Yue-Lan; Liang, Hong; Chen, Zhen-Feng

    2016-11-29

    [Pd(L)(DMSO)Cl2] (1) and [Pt(L)(DMSO)Cl2] (2) with 9-amino-oxoisoaporphine (L), were synthesized and characterized. 1 and 2 are more selectively cytotoxic to Hep-G2 cells versus normal liver cells (HL-7702). Various experiments showed that 2 acted as telomerase inhibitors targeting G4-DNA and triggered cell apoptosis by interacting with c-myc G4-DNA. Furthermore, 2 significantly induced cell cycle arrest at both G2/M and S phase, which leading to the down-regulation of cdc25 A, cyclin D, cyclin B, cyclin A and CDK2 and the up-regulation of p53, p27, p21,chk1 and chk2. In addition, 2 also caused mitochondrial dysfunction. Taken together, we found that 2 exerted its cytotoxic activity mainly via inhibiting telomerase by interaction with c-myc G4-DNA and disruption of mitochondrial function.

  7. mad—overexpression down regulates the malignant growth and p53 mediated apoptosis in human hepatocellular carcinoma BEL—7404 cells

    Institute of Scientific and Technical Information of China (English)

    ZHANHUA; YONGHUAXU

    1999-01-01

    Mad protein has been shown as an antagonist of cMyc protein in some cell lines.The effect of Mad protein to the malignant phenotype of human hepatoma BEL-7404 cell line was investigated experimentally.An eukarryotic vector pCDNA Ⅲ containing full ORF fragment of mad cDNA was transfected into targeted cells.Under G418 selection,stable Mad-overexpressed cells were cloned.Studies on the effect of Mad over-expression in cell proliferation and cell cycle revealed that cell morphology of the Mad-overexpressed BEL-7404-M1 cells was significantly different from the parent and control vector transfected cells.DNA synthesis,cell proliferation and anchorage-independent growth in soft-agar of the madtransfected cells were partially inhibited in comparison to control cells.Flos cytometry analysis indicated that mad over-expression might block more transfectant cells at G0/G1 phase,resulting in the retardation of cell proliferation.RT-PCR detected a marked inhibition of the expression of cdc25A,an important regulator gene of G0/G1 to S phase in cell cycle.It was also found that Mad protein overexpression could greatly suppress p53-mediated apoptosis in BEL-74040M1 cells in the absence of serume.Thus,Mad proteins may function as a negative regulator antagonizing c-Myc activity in the control of cell growth and apoptosis in human hepatocellular carcinoma BEL-7404 cells.

  8. Estrogen Receptor-α and Its Target Gene c-Myc and Pre-implantation Embryos%雌激素受体α及其靶基因c-Myc与植入前胚

    Institute of Scientific and Technical Information of China (English)

    张燕琴

    2012-01-01

    Estrogen receptor-α(Erα), member of the steroid hormone receptor gene superfamily that acts as ligand-inducible transcription factor and plays an important role in regulating the proliferation, differentiation and development of cells and tissues. C-Myc,the Erα target gene,which belongs to Myc gene family, is a kind of nucleoprotein class protooncogene. Erα regulates the expression of c-Myc, at the same time,the expression of c-Myc changing also affects the function of Erα,they are associated with each other. Erα and c-Myc expression are stage-specific in preimplantation embryos, suggesting that their functions might be involved in the development of mammalian preimplantation embryos.%雌激素受体α(ERα)属于类固醇激素受体超家族,是细胞核中需要配体激活的转录因子,对细胞和组织的增殖、分化和发育有重要的调节作用.c-Myc是ERα目的 基因,属于Myc基因家族,是一种核蛋白类的原癌基因.ERα调控着c-Myc的表达,而c-Myc的表达变化也影响着ERα的功能发挥,彼此之间存在关联.它们在哺乳动物植入前胚中呈阶段特异性表达,在植入前胚发育中发挥一定作用.

  9. Microwave-assisted synthesis of arene ruthenium(II) complexes [(η⁶-RC₆H₅)Ru(m-MOPIP)Cl]Cl (R = -H and -CH₃) as groove binder to c-myc G4 DNA.

    Science.gov (United States)

    Wu, Qiong; Chen, Tianfeng; Zhang, Zhao; Liao, Siyan; Wu, Xiaohui; Wu, Jian; Mei, Wenjie; Chen, Yanhua; Wu, Weili; Zeng, Lingli; Zheng, Wenjie

    2014-06-28

    Two arene Ru(II) complexes coordinated by 2-(3-methoxyphenyl)imidazole[4,5-f][1,10]phenanthroline, [(η(6)-RC6H5)Ru(m-MOPIP)Cl]Cl (R = H, ; R = CH3, 2), have been prepared under microwave irradiation; the crystal structure of 2 exhibits a typical "piano stool" conformation, with bond angles for N1-Ru1-Cl1 86.02 (14)° and N2-Ru1-Cl1 84.51 (14)°. The Ru-C distance for the Ru atom bound to the benzene ring is about 0.2178(8) nm, and the average Ru-N distance for Ru atom to the two chelating N atoms is about 0.2092(4) nm. The evaluation of in vitro anticancer activities revealed that these synthetic Ru(II) complexes selectively inhibited the growth of HepG2 hepatocellular carcinoma cells, with low cytotoxicity toward LO2 human normal liver cells. The results demonstrated that the complexes exhibited great selectivity between human cancer and normal cells by comparing with the ligand m-MOPIP. Furthermore, complexes 1 and 2 could bind to c-myc G4 DNA in groove binding mode in promising affinity, and the insertion of the methyl groups in the arene ligand contributed to strengthen the binding affinity. This was also confirmed by molecular docking calculation and (1)H NMR analysis which showed that both 1 and 2 can bind in the loop constructed by A6-G9 and G21-A25 base pairs in c-myc G4 DNA to block the replication of c-myc oligomer. Taken together, these results suggest that arene Ru(II) complexes display application potential as small molecule inhibitors of c-myc G4 DNA.

  10. Rate of CRL4(CRBN) substrate Ikaros and Aiolos degradation underlies differential activity of lenalidomide and pomalidomide in multiple myeloma cells by regulation of c-Myc and IRF4.

    Science.gov (United States)

    Bjorklund, C C; Lu, L; Kang, J; Hagner, P R; Havens, C G; Amatangelo, M; Wang, M; Ren, Y; Couto, S; Breider, M; Ning, Y; Gandhi, A K; Daniel, T O; Chopra, R; Klippel, A; Thakurta, A G

    2015-10-02

    Recent discoveries suggest that the critical events leading to the anti-proliferative activity of the IMiD immunomodulatory agents lenalidomide and pomalidomide in multiple myeloma (MM) cells are initiated by Cereblon-dependent ubiquitination and proteasomal degradation of substrate proteins Ikaros (IKZF1) and Aiolos (IKZF3). By performing kinetic analyses, we found that the downregulation or proteasomal degradation of Ikaros and Aiolos led to specific and sequential downregulation of c-Myc followed by IRF4 and subsequent growth inhibition and apoptosis. Notably, to ensure growth inhibition and cell death, sustained downregulation of Ikaros and Aiolos, c-Myc or IRF4 expression was required. In addition, we found that the half-maximal rate, rather than the final extent of Ikaros and Aiolos degradation, correlated to the relative efficacy of growth inhibition by lenalidomide or pomalidomide. Finally, we observed that all four transcription factors were elevated in primary MM samples compared with normal plasma cells. Taken together, our results suggest a functional link between Ikaros and Aiolos, and the pathological dysregulation of c-Myc and IRF4, and provide a new mechanistic understanding of the relative efficacy of lenalidomide and pomalidomide based on the kinetics of substrate degradation and downregulation of their downstream targets.

  11. Rate of CRL4CRBN substrate Ikaros and Aiolos degradation underlies differential activity of lenalidomide and pomalidomide in multiple myeloma cells by regulation of c-Myc and IRF4

    Science.gov (United States)

    Bjorklund, C C; Lu, L; Kang, J; Hagner, P R; Havens, C G; Amatangelo, M; Wang, M; Ren, Y; Couto, S; Breider, M; Ning, Y; Gandhi, A K; Daniel, T O; Chopra, R; Klippel, A; Thakurta, A G

    2015-01-01

    Recent discoveries suggest that the critical events leading to the anti-proliferative activity of the IMiD immunomodulatory agents lenalidomide and pomalidomide in multiple myeloma (MM) cells are initiated by Cereblon-dependent ubiquitination and proteasomal degradation of substrate proteins Ikaros (IKZF1) and Aiolos (IKZF3). By performing kinetic analyses, we found that the downregulation or proteasomal degradation of Ikaros and Aiolos led to specific and sequential downregulation of c-Myc followed by IRF4 and subsequent growth inhibition and apoptosis. Notably, to ensure growth inhibition and cell death, sustained downregulation of Ikaros and Aiolos, c-Myc or IRF4 expression was required. In addition, we found that the half-maximal rate, rather than the final extent of Ikaros and Aiolos degradation, correlated to the relative efficacy of growth inhibition by lenalidomide or pomalidomide. Finally, we observed that all four transcription factors were elevated in primary MM samples compared with normal plasma cells. Taken together, our results suggest a functional link between Ikaros and Aiolos, and the pathological dysregulation of c-Myc and IRF4, and provide a new mechanistic understanding of the relative efficacy of lenalidomide and pomalidomide based on the kinetics of substrate degradation and downregulation of their downstream targets. PMID:26430725

  12. Altered expression of Bcl-2, c-Myc, H-Ras, K-Ras, and N-Ras does not influence the course of mycosis fungoides

    Science.gov (United States)

    Maj, Joanna; Jankowska-Konsur, Alina; Plomer-Niezgoda, Ewa; Sadakierska-Chudy, Anna

    2013-01-01

    Introduction Data about genetic alterations in mycosis fungoides (MF) are limited and their significance not fully elucidated. The aim of the study was to explore the expression of various oncogenes in MF and to assess their influence on the disease course. Material and methods Skin biopsies from 27 MF patients (14 with early MF and 13 with advanced disease) and 8 healthy volunteers were analyzed by real-time polymerase chain reaction (PCR) to detect Bcl-2, c-Myc, H-Ras, K-Ras and N-Ras expression. All PCR reactions were performed using an Applied Biosystems 7900HT Fast Real-Time PCR System and interpreted using Sequence Detection Systems software which utilizes the comparative delta Ct method. The level of mRNA was normalized to GAPDH expression. All data were analyzed statistically. Results All evaluated oncogenes were found to be expressed in the skin from healthy controls and MF patients. Bcl-2 (–4.2 ±2.2 vs. –2.2 ±1.1; p = 0.01), H-Ras (–3.0 ±3.3 vs. 0.6 ±2.6; p = 0.01) and N-Ras (–3.6 ±2.0 vs. –1.1 ±2.4; p = 0.03) were expressed at significantly lower levels in MF. No relationships between oncogene expression and disease stage, presence of distant metastases and survival were observed (p > 0.05 for all comparisons). Conclusions The pathogenic role and prognostic significance of analyzed oncogenes in MF seem to be limited and further studies are needed to establish better prognostic factors for patients suffering from MF. PMID:24273576

  13. GDNF Up-Regulates c-Myc Transcription via the PI3K/Akt Pathway to Promote Dairy Goat Male Germline Stem Cells (mGSC) Proliferation

    Institute of Scientific and Technical Information of China (English)

    SUN Jun-wei; ZHU Hai-jing; LIU Chao; LI Ming-zhao; HUA Jin-lian

    2013-01-01

    Studies have demonstrated that regulation of GDNF on male germline stem cells (mGSCs) mainly through Ras/Erk1/2, Src family kinase and PI3K/Akt signaling pathways, but the signaling pathways GDNF-mediated are different when the species and cell lines varied. Whether GDNF regulates self-renewal of mGSCs isolated from livestock has not been reported. Here, we purified mGSCs from dairy goat testis using mixed enzymes and fibronectin. Immunofluoresce staining revealed the cultured dairy mGSCs expressed Vasa, Nanos2, Ngn3, Tert, Dazl, Lin28, Oct4, CD49f, Stra8 and GFRa1, reflecting that these cells were mGSCs phenotype. Then we cultured these dairy goat mGSCs in different concentrations of GDNF (0, 5, 10, or 20 ng mL-1) to optimize the best concentration of GDNF to sustain the dairy goat mGSCs self-renewal, after that the inhibitor of PI3K (LY294002, 10μmol L-1) was added to the medium which contains the optimal concentration of GDNF we obtained by experiments. The mGSCs cultured in different media were compared through the population doubling time (PDT), capacity of cell proliferation evaluated by PCNA and BrdU immunofluorescence staining, RT-PCR, QRT-PCR, Western blotting and flow cytometry. Results showed that 10 ng mL-1 was the optimal concentration of GDNF to maintain goat mGSCs self-renewal and GDNF up-regulates c-Myc transcription via the PI3K/Akt pathway to promote goat mGSCs proliferation. This study provides us an efficient model to study the mechanism in mGSCs proliferation and differentiation in goat, and has important implications in unveiling signaling pathways in livestock GSCs.

  14. Expressions of Pokemon and c-myc in colorectal cancer and their clinical significance%Pokemon和c-myc在结直肠癌中的表达及临床意义

    Institute of Scientific and Technical Information of China (English)

    郭柏华; 杨章林; 董国钢; 王笑凌; 班雨

    2015-01-01

    目的 检测Pokemon和c-myc在结直肠癌、结直肠腺瘤和正常结直肠黏膜组织中的表达情况,研究结直肠癌组织中Pokemon和c-myc的表达与临床病理因素的关系.方法 收集86例结直肠癌患者肿瘤组织标本,60例结直肠腺瘤组织标本和40例正常结直肠黏膜组织标本.采用免疫组织化学法检测组织中Pokemon和c-myc蛋白表达情况,反转录聚合酶链反应检测组织中Pokemon和c-myc基因表达水平,并分析其与结直肠癌临床病理因素的关系.结果 结直肠癌组织中Pokemon和c-myc蛋白阳性表达率均明显高于结直肠腺瘤组织和正常结直肠黏膜组织[69.8%(60/86)比13.3%(8/60)和5.0%(2/40)、73.3%(63/86)比15.0%(9/60)和2.5%(1/40)],结直肠癌组织中Pokemon和c-myc基因表达水平均明显高于结直肠腺瘤组织和正常结直肠黏膜组织(0.915±0.247比0.358±0.102和0.277±0.085、1.272±0.360比0.398±0.153和0.255 ± 0.097),差异有统计学意义(P<0.05).结直肠癌组织中Pokemon和c-myc基因的表达水平与肿瘤浸润程度、肿瘤分化程度、淋巴结转移、远处转移和Dukes分期有关,差异有统计学意义(P<0.05),但与性别、年龄和肿瘤直径无关(P>0.05).结论 Pokemon和c-myc在结直肠癌组织中高表达,且这种表达与结直肠癌临床病理特征有关,提示Pokemon和c-myc可作为结直肠癌患者临床治疗的评估指标.%Objective To investigate the expressions of Pokemon and c-myc in colorectal cancer,colorectal adenomas and normal colorectal mucosa tissues,and demonstrate its relationship with clinicopathological features and prognosis in patients with colorectal cancer.Methods The specimens were taken from colorectal cancer tissue of 86 patients,colorectal adenomas tissue of 60 patients,and 40 normal colorectal mucosa tissue.The expressions of Pokemon and c-myc protein were detected by immunohistochemistry,and the expressions of Pokemon and c-myc gene were detected by reverse

  15. Pokemon mRNA在乳腺癌中的表达及与c- myc相关性分析%Expression of Pokemon mRNA in breast carcinoma and its relationship to c-myc

    Institute of Scientific and Technical Information of China (English)

    付朝江; 崔明; 徐衍; 王应霞

    2011-01-01

    目的:探讨人乳腺癌中原癌基因c-myc和Pokemon mRNA在乳腺癌组织中的表达及其与乳腺癌发生、转移的相关性.方法:收集浸润性导管癌组织、癌旁乳腺组织、正常乳腺组织各45、20和20例,用原位杂交法检测Pokemon mRNA表达,并用免疫组织化学法检测浸润性导管癌c-myc表达,并进行统计分析.结果:乳腺癌细胞质Pokemon mRNA的表达率为71.2%(37/45),显著高于癌旁正常乳腺组织40%(8/20)、乳腺增生组织25%(5/20), 三者有显著性差异 (P<0.05),细胞质c-myc阳性率分别为86.67%、60.0%、50.0%,三者有显著性差异(P<0.05).细胞质Pokemon mRNA表达与乳腺癌淋巴结转移、组织学分级相关(P<0.05).细胞质c-myc表达与乳腺癌腋窝淋巴结转移相关(P<0.05).45例乳腺癌细胞质Pokemon mRNA与c-myc表达呈正相关(γ=0.585 ,P<0.05).结论:Pokemon mRNA的表达可能在乳腺导管癌的组织发生中起关键作用,c-myc的过度表达可能与乳腺癌Pokemon基因转录激活有关.%Objective: To explore the expression and interaction of Pokemon mRNA and proto - oncogene c - myc in the course of carcinogenesis and metastasis of breast cancer.Methods : The expression of Pokemon mRNA was examined by in situhybridization in 45 cases of breast cancer,20 cases of adjacent noncancerous breast tissue and 20 cases of mammary gland hyperplasia,The expression of c - myc was examined by immunohistochemistry in 45 cases of carcinoma.Results:The rate of strong positive plasma Pokemon mRNA and c - myc expression was significandy higher in breast cancer than in adjacent noncancerous breast tissue and mammary gland hyperplasia ( P < 0.05 ) , the rates of strong positive plasma Pokemon expression were 71.2% ( 37/45 ) ,40% ( 8/20) , 25 % ( 5/20) ;86.67% 、60.0% 、50.0% , respectively.The positive expreasion of Pokemon mRNA and c - myc in breast cancer was strongly related to lympb nodemetastasis(P <0.05) .The expre8aion of Pokemon m

  16. 人胎冠状动脉原位杂交c-myc和jun原癌基因表达%Expression of proto - oncogenes c - myc and jun in human coronary artery ruring development

    Institute of Scientific and Technical Information of China (English)

    蔡维君; 陈新平; 伍校琼; 罗学港

    2004-01-01

    目的研究原癌基因c-myc和jun在人胎冠状动脉发育过程中的表达与平滑肌细胞增殖的关系.方法用原位杂交方法检测,胎龄分别为16周、22周(因治疗需要引产)的胎儿和意外死亡的足月胎儿冠状动脉前降支c-myc mRNA和jun mRNA的表达水平.杂交反应产物用图像分析仪(MIAS300)作定量分析.结果C-myc mRNA原位杂交反应产物与被测血管区域面积的百分比在16周、22周和足月胎儿分别是70、56和10;Jun mRNA的杂交信反应产物与被测血管区域面积的百分比在这三个时期分别是68、53和8.两个原癌基因在不同阶段的表达均具有显著性差异.结论本实验首次报道c-myc和jun在人胎冠状动脉发育过程中平滑肌的表达图型,c-myc和jun在胎儿冠状动脉平滑肌细胞增殖和内膜的形成过程中可能具有重要的调控作用.%Objective: To investigate the expression of protooncogenes, c - myc and jun, in human coronary artery during development. Methods: In situ hybridization was employed to detect c - myc mRNA and jun mRNA in human coronary artery from aborted fetus with embryonic ages from week 16 to 22 due to treatment requirements. In addition, 3 cases of full term human fetus died of accident were also studied. Hybridized signals were quantified with a computer - assisted image - analyzing system ( MIAS 300 ). Results: The ratio of hybridized signal of c - myc to the area of vascular wall detected were 0.7, 0.54 and 0.10 respectively corresponding to the embryonic ages, 16 weeks,22 weeks and full term. Similar results with the ratio of 0.68, 0.53 and 0.08 for jun mRNA at above embryonic ages was also found. The levels of c - myc and jun mRNA expressed at different embryonic stage showed a significant difference. Conclusions: We first reported the expression of proto - oncogenes, c - myc and jun, in human coronary artery during embryonic development. These two proto - oncogenes may play an important role in the

  17. Ku70 acetylation and modulation of c-Myc/ATF4/CHOP signaling axis by SIRT1 inhibition lead to sensitization of HepG2 cells to TRAIL through induction of DR5 and down-regulation of c-FLIP

    DEFF Research Database (Denmark)

    Kim, Mi-Ju; Hong, Kyung-Soo; Kim, Hak-Bong

    2013-01-01

    In this study, we investigated the role of c-Myc/ATF4/CHOP signaling pathway in sensitization of human hepatoma HepG2 cells to TRAIL. Knockdown of SIRT1 or treatment with SIRT1 inhibitor caused the up-regulation of DR5 and down-regulation of c-FLIP through modulation of c-Myc/ATF4/CHOP pathway, a...

  18. 人类p53和c-myc同源基因在玉米颖果发育过程中的表达%Expressions of Human p53 and c-myc Gene Homologues During Caryopsis Development in Maize

    Institute of Scientific and Technical Information of China (English)

    亓翠英; 宁顺斌; 王宁; 李立家; 宋运淳

    2003-01-01

    肿瘤抑制基因p53和原癌基因c-myc已被证明在动物中高度保守并参与许多PCD过程.这两个基因编码的同源蛋白及其RNA在玉米中的存在已有报道,并且其DNA同源序列已利用荧光原位杂交定位在玉米相应的染色体上.利用免疫组织化学方法探测了与人类p53和c-myc基因同源的玉米基因在玉米颖果发育过程中的时空表达模式.结果发现,在授粉后的一定阶段,在反足细胞、珠被、未成熟的胚乳、子房壁、导管组织和糊粉层中,p53同源基因表达强烈,c-myc同源基因的表达相反,在授粉后的这些组织中基本不表达,而在授粉前的中央细胞的极核中表达水平较高.TUNEL检测显示,在p53同源基因呈现高水平表达的地方,DNA断裂信号强烈.在动物细胞中,p53和c-myc起相反的调节作用,这与其同源基因在玉米中的作用模式相似.由此说明p53和c-myc同源基因可能在玉米颖果发育PCD过程中起重要作用,并进一步推论高等植物PCD和动物细胞凋亡存在一定的保守性机制.%Tumor suppressor gene p53 and proto-oncogene c-myc have been proved to be highly conserved and participate in many PCD processes in animals.In maize,proteins and RNAs related to p53 and c-myc have already been reported and the sequences homologous to these two genes have also been localized onto maize chromosomes by FISH.In this study,using immunohistochemistry we investigated the expression patterns of maize genes homologous to human p53 and c-myc during caryopsis development stages in maize.In a giving stage after pollination,p53 homologue showed high levels in the antipodal cells,integument,immature endosperm,ovary wall,tracheary elements,and aleurone layer,while c-myc homologue showed low levels in these tissues,only before pollination showed high expression in polar nucleus.The results of TUNEL assay demonstrated that TUNEL positive signals were detected where p53 homologue showed high expression

  19. Reevesioside A, a cardenolide glycoside, induces anticancer activity against human hormone-refractory prostate cancers through suppression of c-myc expression and induction of G1 arrest of the cell cycle.

    Directory of Open Access Journals (Sweden)

    Wohn-Jenn Leu

    Full Text Available In the past decade, there has been a profound increase in the number of studies revealing that cardenolide glycosides display inhibitory activity on the growth of human cancer cells. The use of potential cardenolide glycosides may be a worthwhile approach in anticancer research. Reevesioside A, a cardenolide glycoside isolated from the root of Reevesia formosana, displayed potent anti-proliferative activity against human hormone-refractory prostate cancers. A good correlation (r² = 0.98 between the expression of Na⁺/K⁺-ATPase α₃ subunit and anti-proliferative activity suggested the critical role of the α₃ subunit. Reevesioside A induced G1 arrest of the cell cycle and subsequent apoptosis in a thymidine block-mediated synchronization model. The data were supported by the down-regulation of several related cell cycle regulators, including cyclin D1, cyclin E and CDC25A. Reevesioside A also caused a profound decrease of RB phosphorylation, leading to an increased association between RB and E2F1 and the subsequent suppression of E2F1 activity. The protein and mRNA levels of c-myc, which can activate expression of many downstream cell cycle regulators, were dramatically inhibited by reevesioside A. Transient transfection of c-myc inhibited the down-regulation of both cyclin D1 and cyclin E protein expression to reevesioside A action, suggesting that c-myc functioned as an upstream regulator. Flow cytometric analysis of JC-1 staining demonstrated that reevesioside A also induced the significant loss of mitochondrial membrane potential. In summary, the data suggest that reevesioside A inhibits c-myc expression and down-regulates the expression of CDC25A, cyclin D1 and cyclin E, leading to a profound decrease of RB phosphorylation. G1 arrest is, therefore, induced through E2F1 suppression. Consequently, reevesioside A causes mitochondrial damage and an ultimate apoptosis in human hormone-refractory prostate cancer cells.

  20. c-myc、p53和p16的表达及GNAS1基因突变在骨的纤维结构不良中的意义%Abnormal expression of c-myc,p53,p16 protein and GNAS1 gene mutation in fibrous dysplasia

    Institute of Scientific and Technical Information of China (English)

    唐娟; 赵红叶; 郑莉; 张惠箴; 蒋智铭

    2009-01-01

    Objective To study the significance of c-myc,p53 and p16 protein expression in fibrous dysplasia,to detect the GNAS1 gene mutation in fibrous dysplasia,and to explore the property of fibrous dysplasia.Methods The expression of c-myc,p53 and p16 protein was evaluated by immunohistochemistry SP method in 35 cases of fibrous dysplasia including 1 FD with malignancy,1 Mazabraud syndrome and 20 control cases (10 cases of bony callus,10 cases of osteosarcoma). Genomic DNA extraction,PCR amplification and gene sequencing were used to detect GNAS1 gene mutation in 35 cases of fibrous dysplasia.Results C-myc protein immunoreactivity was detected in 91 percentage of FD(P=0.001).Compared with the negative control group,the difference was significant.P16 positive waa detected in 34 FD cases(P=0.001).The difference was significant as compared with the positive control group.Positive p53 protein expression was detected in the only 1 case of fibrous dysplasia with malignant transformation.PCR amplification was successful in 12 of 35 FD cases.Two of the 12 FD cases were detected to have GNAS1 gene mutation,in which 1 case waa FD of Mazabraud syndrome,1 case was a monostotic lesion.Concimiom C-myc could be another protooncogene in addition to c-fos in the fibrous dysplasia disease.P53 protein overexpression could be useful in the diagnosis of FD malignancy and in the prediction of the prognosis of FD.The abnormal expression of the gene p16 might play an important role in the formation of FD.The GNAS1 mutation exist in FD.All of the results indicate that FD could be a neoplasia disease.caused by multiple factors leading to a dysfunction of bone development.%目的 检测c-myc、p53和p16蛋白在骨的纤维结构不良(FD)中的表达及其意义,检测FD中GNAS1基因第8外显子突变,探讨FD的病变性质.方法 采用免疫组织化学SP法检测35例FD(包括1例FD恶变,1例Mazabraud综合征)及20例对照组(10例骨痂、10例骨肉瘤)中c-myc、p53和p16蛋白表达.

  1. Correlation of expression VEGF to expression of protooncogenes of c-fos and c-myc at protein level among various grades of liver cirrhosis%硬变肝组织VEGF的表达与原癌基因c-fos,c-myc 以及肝功能分级的相关性研究

    Institute of Scientific and Technical Information of China (English)

    施宝民; 杨镇; 张黎; 李大鹏

    2001-01-01

    目的探讨血管内皮生长因子(VEGF)在肝硬化发生发展中的作用以及肝脏原癌基因(c-fos,c-myc)与肝功能Child分级的相关关系。方法通过对54例硬变肝组织中的VEGF、c-fos、c-myc蛋白的免疫组化检测,观察VEGF的蛋白水平表达与肝脏功能Child 分级的相关性,同时分析VEGF阳性病例组与阴性病例组c-fos、c-myc的不同表达,来了解二者的相互作用关系。结果 Child A级与Child B级VEGF的表达显著高于Child C级和对照组(P<0.05),而Child A级与Child B级之间差异无显著性意义(P>0.05)。c-fos 及c-myc的表达在VEGF阳性组和阴性组差异无显著性意义(P>0.05)。结论 VEGF的水平可以反映肝脏功能的代偿状态,可能在肝硬化的进程中起着保肝作用;原癌基因c-fos、c-myc与VEGF作用在不同环节。

  2. S-Adenosylmethionine Inhibits the Growth of Cancer Cells by Reversing the Hypomethylation Status of c-myc and H-ras in Human Gastric Cancer and Colon Cancer

    Directory of Open Access Journals (Sweden)

    Jin Luo, Yan-Ni Li, Fei Wang, Wei-Ming Zhang, Xin Geng

    2010-01-01

    Full Text Available A global DNA hypomethylation might activate oncogene transcription, thus promoting carcinogenesis and tumor development. S-Adenosylmethionine (SAM serves as a major methyl donor in biological transmethylation events. The object of this study is to explore the influence of SAM on the status of methylation at the promoter of the oncogenes c-myc, H-ras and tumor-suppressor gene p16 (INK4a, as well as its inhibitory effect on cancer cells. The results indicated that SAM treatment inhibited cell growth in gastric cancer cells and colon cancer cells, and the inhibition efficiency was significantly higher than that in the normal cells. Under standard growth conditions, C-myc and H-ras promoters were hypomethylated in gastric cancer cells and colon cancer cells. SAM treatment resulted in a heavy methylation of these promoters, which consequently downregulated mRNA and protein levels. In contrast, there was no significant difference in mRNA and protein levels of p16 (INK4a with and without SAM treatment. SAM can effectively inhibit the tumor cells growth by reversing the DNA hypomethylation on promoters of oncogenes, thus down-regulating their expression. With no influence on the expression of the tumor suppressor genes, such as P16, SAM could be used as a potential drug for cancer therapy.

  3. TA1 oncofetal rat liver cDNA and putative amino acid permease: temporal correlation with c-myc during acute CCl4 liver injury and variation of RNA levels in response to amino acids in hepatocyte cultures.

    Science.gov (United States)

    Shultz, V D; Campbell, W; Karr, S; Hixson, D C; Thompson, N L

    1999-01-01

    TA1 is a rat liver oncofetal cDNA and a member of an emerging family of evolutionarily conserved molecules with homology to amino acid transporters and permeases. The aim of these studies was to characterize the regulation and role of TA1 in acute rat liver injury by examining its relation to regeneration and metabolic stress. Following a single dose of CCl4, TA1 message was expressed 3-48 h. The major 3.3-kb TA1 transcript correlated temporally with c-myc expression. A novel 2.9-kb TA1 transcript was expressed more variably 24-48 h. TA1 protein was restricted to hepatocytes in G0 and G1 phases of the cell cycle. Relative to CCl4, a much smaller increase in TA1 was noted after partial hepatectomy and TA1 preceded the peak of c-myc expression. In vitro TA1 was not induced in hepatocytes by EGF or the acute-phase cytokines IL-6 and TNF-alpha, but was found to be modulated in response to amino acid availability. TA1 expression increased in media without arginine and glutamine and was repressed by total amino acid levels 5-fold over basal MEM. Together, these results contrast with the constitutive expression observed in transformed cells and suggest an adaptive role for TA1 during liver injury.

  4. Differential regulation of LncRNA-SARCC suppresses VHL-mutant RCC cell proliferation yet promotes VHL-normal RCC cell proliferation via modulating androgen receptor/HIF-2α/C-MYC axis under hypoxia.

    Science.gov (United States)

    Zhai, W; Sun, Y; Jiang, M; Wang, M; Gasiewicz, T A; Zheng, J; Chang, C

    2016-09-15

    It is well established that hypoxia contributes to tumor progression in a hypoxia inducible factor-2α (HIF-2α)-dependent manner in renal cell carcinoma (RCC), yet the role of long noncoding RNAs (LncRNAs) involved in hypoxia-mediated RCC progression remains unclear. Here we demonstrate that LncRNA-SARCC (Suppressing Androgen Receptor in Renal Cell Carcinoma) is differentially regulated by hypoxia in a von Hippel-Lindau (VHL)-dependent manner both in RCC cell culture and clinical specimens. LncRNA-SARCC can suppress hypoxic cell cycle progression in the VHL-mutant RCC cells while derepress it in the VHL-restored RCC cells. Mechanism dissection reveals that LncRNA-SARCC can post-transcriptionally regulate androgen receptor (AR) by physically binding and destablizing AR protein to suppress AR/HIF-2α/C-MYC signals. In return, HIF-2α can transcriptionally regulate the LncRNA-SARCC expression via binding to hypoxia-responsive elements on the promoter of LncRNA-SARCC. The negative feedback modulation between LncRNA-SARCC/AR complex and HIF-2α signaling may then lead to differentially modulated RCC progression in a VHL-dependent manner. Together, these results may provide us a new therapeutic approach via targeting this newly identified signal from LncRNA-SARCC to AR-mediated HIF-2α/C-MYC signals against RCC progression.

  5. Investigation of miRNA Biology by Bioinformatic Tools and Impact of miRNAs in Colorectal Cancer: Regulatory Relationship of c-Myc and p53 with miRNAs

    Directory of Open Access Journals (Sweden)

    Yaguang Xi

    2007-01-01

    Full Text Available MicroRNAs (miRNAs are a class of small non-coding RNAs that mediate gene expression at the posttranscriptional and translational levels and have been demonstrated to be involved in diverse biological functions. Mounting evidence in recent years has shown that miRNAs play key roles in tumorigenesis due to abnormal expression of and mutations in miRNAs. High throughput miRNA expression profiling of several major tumor types has identified miRNAs associated with clinical diagnosis and prognosis of cancer treatment. Previously our group has discovered a novel regulatory relationship between tumor suppressor gene p53 with miRNAs expression and a number of miRNA promoters contain putative p53 binding sites. In addition, others have reported that c-myc can mediate a large number of miRNAs expression. In this review, we will emphasize algorithms to identify mRNA targets of miRNAs and the roles of miRNAs in colorectal cancer. In particular, we will discuss a novel regulatory relationship of miRNAs with tumor suppressor p53 and c-myc. miRNAs are becoming promising novel targets and biomarkers for future cancer therapeutic development and clinical molecular diagnosis.

  6. Bromodichloromethane induces cell proliferation in different tissues of male F344 rats by suppression of E-cadherin expression via hypermethylation or transcriptional activation of c-myc and cyclin D1.

    Science.gov (United States)

    Liao, Jing; Li, Xiao-Feng; Zhou, Shun-Chang; Luo, Yan; Liu, Ai-Lin; Lu, Wen-Qing

    2013-11-25

    The aim of this study was to investigate the mechanism of bromodichloromethane (BDCM) - induced cell proliferation in different tissues of male F344 rats. Rats were administered at doses of 0 and 100mg/kg/day BDCM dissolved in corn oil by gavage for 5 days/week for 1, 4, 8 and 12 weeks. Then the colon, kidney and liver were collected. No histologic lesions were observed in the colon of rats exposed to BDCM, while there were mild nephrotoxicity and marginal hepatotoxicity related to BDCM treatment. Moreover, BDCM enhanced cell proliferation in the colon and kidney but not in the liver. In colons, hypermethylation in E-cadherin promoter might be associated with inhibition of mRNA and protein expression after 12 weeks of BDCM exposure. In kidneys, BDCM decreased E-cadherin mRNA expression, accompanying with transcriptional activation of c-myc and cyclin D1. However, suppression of E-cadherin mRNA and protein expression occurred in the absence of significant changes in DNA methylation. Therefore, suppression of E-cadherin expression via hypermethylation or transcriptional activation of c-myc and cyclin D1 may be involved in BDCM-induced cell proliferation in different tissues of male F344 rats.

  7. Determination of Mutation of C-myc Oncogene in Gastric Cancer by Capillary Electrophoresis%毛细管电泳法检测癌基因C-myc胃癌中基因点突变

    Institute of Scientific and Technical Information of China (English)

    谢希晖; 王荣; 贾正平; 谢华; 张爱梅; 徐娟; 王晓莉; 王先华

    2011-01-01

    癌基因C-myc激活和突变在胃癌形成过程中起着重要作用.通过毛细管电泳(CE)方法检测50例胃癌患者中C-myc基因突变,建立一种准确、快速诊断早期胃癌的方法.本实验采用PCR扩增胃癌及癌旁正常组织中C-myc基因第二外显子易发突变的部位基因序列,扩增样品分别经96℃变性和EcoRV酶切处理,以PAGE-SSCP,CE-SSCP,CE-RFLP分别对其突变情况进行检测.优化的CE检测条件:筛分介质PEO浓度3.0%,pH 8.2,电压15 kV,温度15℃;荧光检测:λex=488 nm,λem=520 nm.检测结果:C-myc基因总突变率为20.0% (10/50).测序分析结果显示C-myc基因第二外显子第53密码子存在点突变,碱基A变为碱基T(GAT→GTT),碱基的改变使氨基酸由亮氨酸替代为谷氨酰胺.本研究数据证实C-myc基因突变与胃癌的形成紧密相关,CE检测C-myc突变基因可作为胃癌早期诊断的简便可靠的方法.%Activation of C-myc oncogene by mutation has been reported to play an important role in gastric cancer tumorigenesis. We determined C-myc mutation in 50 patients with gastric cancer by capillary electrophoresis (CE) to establish an exactly and volant clinical diagnostic method in early gastric cancer. In this experiment, genomic DNA was extracted from normal tissue and gastric cancer tissue and the sequence of C-myc oncogene on exon 2 (possible with high mutation frequency) in the extracted genomic DNA was amplified by polymerase chain reaction (PCR). Then amplified DNA samples were denatured at 96 oC and digested by EcoRV and detected by PAGE-single strand conformation polymorphism (SSCP), CE-SSCP, CE-restriction fragment length polymorphism (RFLP). The optimum CE detection conditions including 3. 0% sieving medium poly(ethylene oxide) (PEO), pH 8. 2, separation voltage of 15 kV and temperature of 15 oC were adopted. The laser-induced fluorescence detector was set at λex = 488 nm, λem = 520 nm. The results reveal that the mutation frequency of C-myc

  8. Reptin is required for the transcription of telomerase reverse transcriptase and over-expressed in gastric cancer

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    Liu Tiantian

    2010-05-01

    Full Text Available Abstract Background Telomerase is activated in oncogenesis, which confers an immortal phenotype to cancer cells. The AAA + ATPase Reptin is required for telomerase biogenesis by maintaining telomerase RNA (hTER stability and is aberrantly expressed in certain cancers. Given its role in chromatin remodeling and transcription regulation, we determined the effect of Reptin on the transcription of the telomerase reverse transcriptase (hTERT gene, a key component of the telomerase complex and its expression in gastric cancer. Results Knocking down Reptin or its partner Pontin using small interfering RNA in gastric and cervical cancer cells led to significant decreases in hTERT mRNA, but hTERT promoter activity was inhibited in only Reptin-depleted cells. Reptin interacted with the c-MYC oncoprotein and its stimulatory effect on the hTERTpromoter was significantly dependent on functional E-boxes in the promoter. Moreover, Reptin bound to the hTERT proximal promoter and the loss of the Reptin occupancy led to dissociation of c-MYC from the hTERT promoter in Reptin-depleted cells. Reptin inhibition dramatically impaired clonogenic potential of gastric cancer cells by inducing cell growtharrest and over-expression of Reptin was observed in primary gastric cancer specimens. Conclusions The hTERT gene is a direct target of Reptin, and hTERT transcription requires constitutive expression of Reptin and its cooperation with c-MYC. Thus, Reptin regulates telomerase at two different levels. This finding, together with the requirementof Reptin for the clonogenic potential of cancer cells and its over-expression in gastriccancer and other solid tumors, suggests that Reptin may be a putative therapeutic target.

  9. Differential 14-3-3 sigma DNA methylation and expression in c-myc- and activated H-ras-transformed cells under r- and K-selection.

    Science.gov (United States)

    Sato, Hiroyuki; Nakamura, Yukari; Motokura, Toru

    2006-05-08

    We cloned rat 14-3-3 sigma, a mediator of p53 tumor suppressor, as a target of K-selection. 14-3-3 sigma expression is suppressed with DNA methylation in breast cancers while its overexpression with hypomethylation is frequent in pancreatic cancers. These opposite findings were recapitulated through r- and K-selection of transformed rat embryo fibroblasts. 14-3-3 sigma expression was suppressed with DNA methylation after r-selection and the gene was overexpressed and demethylated in K-selected cells. 5-aza-2'-deoxycytidine recovered 14-3-3 sigma expression in r-selected cells. The presence of heterogeneous methylation patterns and expression levels before selection suggests that different 14-3-3 sigma expression levels play a role as a prerequisite for selection and clonal evolution.

  10. Neuroprotective effects of prostaglandin A1 and its effect on IKK/IkB/NF-kB/c-myc signaling pathway in rat models of permanent focal cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Hui-lingZHANG; Zhen-lunGU; Zheng-hongQIN

    2005-01-01

    AIM Prostaglandin A1(PGA1) is a cyclopentenone prostaglandin. Recently, we reported that PGA1 can inhibit excitotoxin-induced apoptosis of striatal neurons in vivo and rotenone-induced apoptosis ofcultured SH-SY5Y cells, suggesting that PGA1 may have neuroprotective efficacy, possibly mediated by inhibition of NF-kB activation. The present study evaluated the neuroprotective potential of PGA1 and its effect on IKK/I( B/NF-kB/c-myc signaling pathway in rat models of permanent focal cerebral ischemia. METHODS Permanent middle cerebral artery occlusion (pMCAO) model was constructed by intraluminal suture cannulation through the internal carotid artery in Wistar rats.

  11. Overexpression of PD2 leads to increased tumorigenicity and metastasis in pancreatic ductal adenocarcinoma

    Science.gov (United States)

    Vaz, Arokia Priyanka; Deb, Shonali; Rachagani, Satyanarayana; Dey, Parama; Muniyan, Sakthivel; Lakshmanan, Imayavaramban; Karmakar, Saswati; Smith, Lynette; Johansson, Sonny; Lele, Subodh; Ouellette, Michel; Ponnusamy, Moorthy P.; Batra, Surinder K.

    2016-01-01

    Pancreatic differentiation 2 (PD2), an important subunit of the human PAF complex, was identified after differential screening analysis of 19q13 amplicon, and its overexpression induces oncogenic transformation of NIH3T3 cells, hence raising the possibility of a role for PD2 in tumorigenesis and metastasis. To test this hypothesis, we analyzed here the functional role and clinical significance of PD2 in pancreatic ductal adenocarcinoma (PDAC) and its pathogenesis. Using immunohistochemical analysis, we found that PD2 is detected in the acini but not in the ducts in the normal pancreas. In human PDAC specimens, PD2 was instead primarily detected in the ducts (12/48 patients 25%; p-value < 0.0001), thereby showing that PDAC correlates with increased ductal expression of PD2. Consistently, PD2 expression was increased in telomerase-immortalized human pancreatic ductal cells (HPNE cells) modified to express the HPV16 E6 and E7 proteins, whose respective functions are to block p53 and RB. In addition, ectopic expression of PD2 in PDAC cells (Capan-1 and SW1990) led to increased clonogenicity and migration in vitro, and tumor growth and metastasis in vivo. Interestingly, PD2 overexpression also resulted in enrichment of cancer stem cells (CSCs) and upregulation of oncogenes such as c-Myc and cell cycle progression marker, cyclin D1. Taken together, our results support that PD2 is overexpressed in the ducts of PDAC tissues, and results in tumorigenesis and metastasis via upregulation of oncogenes such as c-Myc and cyclin hence D1 implicating PD2 upregulation in pancreatic oncogenesis with targeted therapeutic potential. PMID:26689992

  12. The Phosphoinositide 3-Kinase p110α Isoform Regulates Leukemia Inhibitory Factor Receptor Expression via c-Myc and miR-125b to Promote Cell Proliferation in Medulloblastoma.

    Directory of Open Access Journals (Sweden)

    Fabiana Salm

    Full Text Available Medulloblastoma (MB is the most common malignant brain tumor in childhood and represents the main cause of cancer-related death in this age group. The phosphoinositide 3-kinase (PI3K pathway has been shown to play an important role in the regulation of medulloblastoma cell survival and proliferation, but the molecular mechanisms and downstream effectors underlying PI3K signaling still remain elusive. The impact of RNA interference (RNAi-mediated silencing of PI3K isoforms p110α and p110δ on global gene expression was investigated by DNA microarray analysis in medulloblastoma cell lines. A subset of genes with selectively altered expression upon p110α silencing in comparison to silencing of the closely related p110δ isoform was revealed. Among these genes, the leukemia inhibitory factor receptor α (LIFR α was validated as a novel p110α target in medulloblastoma. A network involving c-Myc and miR-125b was shown to be involved in the control of LIFRα expression downstream of p110α. Targeting the LIFRα by RNAi, or by using neutralizing reagents impaired medulloblastoma cell proliferation in vitro and induced a tumor volume reduction in vivo. An analysis of primary tumors revealed that LIFRα and p110α expression were elevated in the sonic hedgehog (SHH subgroup of medulloblastoma, indicating its clinical relevance. Together, these data reveal a novel molecular signaling network, in which PI3K isoform p110α controls the expression of LIFRα via c-Myc and miR-125b to promote MB cell proliferation.

  13. HeLa和SiHa细胞中Skp2、p27和C-myc的表达%Expressions of Skp2、p27 and C-myc in HeLa and SiHa Cells

    Institute of Scientific and Technical Information of China (English)

    薛翔; 公丕军; 范引侠

    2012-01-01

    Objective: To test the expressions of S-phase kinase-associated protein 2 (Skp2), C-myc and p27 in HeLa and SiHa cells from the levels of RNA and protein and to investgate the meaning of those indexes in cervical cancerous cells. Methods:We tested the expressions of Skp2, p27 and C-myc in HeLa and SiHa cell lines by immunohistochemistry, western blotting as well as semiquantitative PCR . Results: Immunohistochemistry results showed that the expressions of Skp2 and C-myc were obviously stronger in HeLa cells than those in SiHa cells (P =0.032 and P = 0.026). While the expression of p27 was weaker in HeLa cells than that in SiHa cells (P=0.035). Western blot results showed that the expressions of endogenous Skp2 and C-myc protein in HeLa cells were as 2.8 and 1.5 times of SiHa cells respectively. However, the expression of p27 protein in SiHa cells was as 2.7 times of those in HeLa cells. RT-PCR results showed that the expression levels of endogenous Skp2 and C-myc mRNA in HeLa cells were higher than those in Si-Hha cells(P = 0.034 and P = 0.028, respectively), meanwhile, the expression of p27mRNA in SiHa cells was higher than that of HeLa cells (P=0.002). Conclusions: The expressions of Skp2 and C-myc in HeLa cells are obviously higher than those in SiHa cells. The expression of p27 in HeLa cells is lower than that in SiHa cells.%目的:检测S期激酶相关蛋白2( Skp2)、C-myc、p27在宫颈癌HeLa及SiHa细胞系中的表达,明确这些指标在宫颈癌细胞系表达的意义.方法:通过细胞免疫组化、Western blot、RT-PCR技术分析Skp2、p27和C-myc在蛋白和mRNA水平表达的差异.结果:免疫组化显示:HeLa细胞中Skp2和C-myc表达强度高于SiHa细胞(P=0.032和P=0.026),而HeLa细胞中p27蛋白表达弱于SiHa细胞(P=0.035).Western blot显示:在HeLa细胞中Skp2和C-myc蛋白表达分别是SiHa细胞表达量的2.8倍和1.5倍;而SiHa细胞中的p27蛋白的表达水平是He-La细胞中表达的2.7倍.RT-PCR结果

  14. CyclinA、C-myc在皮肤瘢痕及瘢痕癌组织中的表达及意义%Expressions and Significance of CyclinA and C-myc in Skin Scar and Skin Scar Carcinoma

    Institute of Scientific and Technical Information of China (English)

    郭瑞珍; 周开梅; 王燕

    2011-01-01

    目的 探讨CyclinA、C-myc在皮肤病理性瘢痕和瘢痕癌组织中的表达及意义.方法以病理性皮肤瘢痕、皮肤瘢痕癌组织为研究对象,以正常皮肤组织为对照.采用免疫组织化学(SP法)分别检测CyclinA、C-myc蛋白的表达,采用核酸分子原位杂交法检测CyclinA mRNA的表达,所有数据输入计算机后运用SPSS 16.0软件包进行统计学分析.结果 (1)CyclinA、CyclinA mRNA在正常皮肤和皮肤瘢痕上皮中的表达呈阴性或弱阳性,在瘢痕癌组织中呈强阳性.瘢痕癌组的表达(平均吸光度和阳性面积)与正常皮肤组及皮肤瘢痕组比较,差异均有统计学意义(P<0.01);但正常皮肤组与瘢痕组比较,差异无统计学意义(P>0.05).(2)C-myc蛋白在正常皮肤中的表达呈弱阳性,在皮肤瘢痕上皮中呈阳性,在瘢痕癌组织中呈强阳性.且两两比较差异均有统计学意义(P<0.05).(3)相关分析显示,在皮肤瘢痕癌中,CyclinA与CyclinA mRNA(r=0.766,P<0.01)、CyclinA与C-myc蛋白(r=0.804,P<0.01)的表达均呈正相关.结论(1)CyclinA及其mRNA、C-myc的高表达,可能与皮肤瘢痕癌的发生有关;(2)C-myc蛋白的高表达与皮肤瘢痕上皮癌变有相关性.(3)在瘢痕癌中CyclinA同时存在蛋白水平和基因水平的异常表达.%Objective To study the expressions and significance of CyclinA and C-myc in skin Scar and skin Scar Carcinoma. Methods We compared pathological skin scar tissues and skin scar carcinoma tissues with normal skin tissues. The expression of CyclinA and C-myc proteins were detected by the immu-nohistochemical method of SP. And the expression of CyclinA mRNA was detected by in situ hybridization. All data were input into the computer and statistically analyzed with SPSS (16. 0) software. Results (1) CyclinA and its mRNA showed strong positive expression in scar carcinoma tissues, negative or weakly positive expression in normal skin epidermis and pathological skin scar epithelium

  15. 多态性上皮黏蛋白1和原癌基因C-myc在老年甲状腺乳头状癌患者中的表达%Expression changes of mucin1 and c-myc gene in elderly papillary thyroid carcinoma patient

    Institute of Scientific and Technical Information of China (English)

    胡耀杰; 罗晓燕; 杨岳; 陈春悠; 张志勇; 郭欣

    2014-01-01

    Objective To study the changes of expression of mucin1 (MUC1) and protooncogene proteins C-myc (C-myc) gene in elderly papillary thyroid carcinoma.Methods The expression levels of MUC1 and C-myc were examined by immunohistochemical methods in 58 sample of thyroid carcinoma,35 nodular goiter and in 30 normal thyroid tissue.Results The detective rate of MUC1 in 58 specimens of thyroid carcinoma was 77.6% (45/58),while 90.0% (9/10) in those with infiltration and 88.2 % (15/17) in those with metastasis.The detective rate of C-myc in 58 specimens of thyroid carcinoma was 81.0 % (47/58),and 100.0 % (17/17) in those with metastasis.Conclusions The differences in MUC1 or C myc expression and in thyroid carcinoma infiltration and lymph node metastasia between benign versus malignant thyroid tumor are statistically significant.%目的 探讨多态性上皮黏蛋白1 (mucin 1,MUC1)和原癌基因蛋白质(proto-oncogene proteins C-myc,C-Myc)基因在老年甲状腺乳头状癌(PTC)患者中的表达和临床意义. 方法 应用免疫组化法检测30例腺瘤旁正常甲状腺组织、35例结节性甲状腺肿和58例PTC标本中MUC1和C-myc的表达水平. 结果 MUC1基因在甲状腺癌中表达率为77.6%(45/58),MUC1在有局部浸润和淋巴结转移患者中的检出率分别为90.0%(9/10)和88.2%(15/17).C-myc基因在甲状腺癌中阳性率为81.0% (47/58);C-myc在淋巴结转移组中的检出率为100.0% (17/17). 结论 MUC1和C myc的阳性表达在甲状腺良恶性病变间有差异,并与甲状腺癌的转移有关.

  16. Complex Biological Systems Analysis of Cell Cycling Models in Carcinogenesis: I. The essential roles of modifications in the c-Myc, TP53/p53, p27 and hTERT modules in Cancer Initiation and Progression

    CERN Document Server

    Prisecaru, V I

    2004-01-01

    A new approach to the integration of results from a modular, complex biological systems analysis of nonlinear dynamics in cell cycling network transformations that are leading to carcinogenesis is proposed. Carcinogenesis is a complex process that involves dynamically inter-connected biomolecules in the intercellular, membrane, cytosolic, nuclear and nucleolar compartments that form numerous inter-related pathways referred to as networks. One such network module contains the cell cyclins whose functions are essential to cell cycling and division. Cyclins are proteins that also link to several critical pro-apoptotic and other cell cycling/division components, such as: c-Myc, p27, the tumor suppressor gene TP53 and its product-- the p53 protein with key roles in controlling DNA repair, inducing apoptosis and activating p21 (which can depress cell cyclins if activated), mdm2(with its biosynthesis activated by p53 and also, in its turn, inhibiting p53), p21, the Thomsen-Friedenreich antigen(T- antigen),Rb,Bax, Ba...

  17. Triphala Extract Suppresses Proliferation and Induces Apoptosis in Human Colon Cancer Stem Cells via Suppressing c-Myc/Cyclin D1 and Elevation of Bax/Bcl-2 Ratio

    Directory of Open Access Journals (Sweden)

    Ramakrishna Vadde

    2015-01-01

    Full Text Available Colon cancer is the second leading cause of cancer related deaths in the USA. Cancer stem cells (CSCs have the ability to drive continued expansion of the population of malignant cells. Therefore, strategies that target CSCs could be effective against colon cancer and in reducing the risk of relapse and metastasis. In this study, we evaluated the antiproliferative and proapoptotic effects of triphala, a widely used formulation in Indian traditional medicine, on HCT116 colon cancer cells and human colon cancer stem cells (HCCSCs. The total phenolic content, antioxidant activity, and phytochemical composition (LC-MS-MS of methanol extract of triphala (MET were also measured. We observed that MET contains a variety of phenolics including naringin, quercetin, homoorientin, and isorhamnetin. MET suppressed proliferation independent of p53 status in HCT116 and in HCCSCs. MET also induced p53-independent apoptosis in HCCSCs as indicated by elevated levels of cleaved PARP. Western blotting data suggested that MET suppressed protein levels of c-Myc and cyclin D1, key proteins involved in proliferation, and induced apoptosis through elevation of Bax/Bcl-2 ratio. Furthermore, MET inhibited HCCSCs colony formation, a measure of CSCs self-renewal ability. Anticancer effects of triphala observed in our study warrant future studies to determine its efficacy in vivo.

  18. 鸟氨酸脱羧酶和c-myc在胃癌及其癌前病变组织中的表达及意义%Expression of ornithine decarboxylase and c-myc in gastric cancer and premalignant lesions and its significance

    Institute of Scientific and Technical Information of China (English)

    魏小娟; 王云溪

    2016-01-01

    Objective:To detect the expression of ODC and c-myc in chronic superficial gastritis, intestinal metaplasia, atypical hy-perplasia and gastric carcinoma, to explore the correlation and significance of the expression of ODC and c-myc in gastric carcinoma and precancerous lesions.Methods:The expressions of ODC and c-myc were detected by RT-PCR and immunohistochemistry in 18 cases of chronic superficial gastritis( CSG) , 18 chronic atrophic gastritis with intestinal metaplasia CAG( with IM) ,12 gastric dysplasia ( DYS) and 30 gastric carcinoma ( GC) , to explore the correlation between ODC and c-myc and their relationship with precancerous gastric le-sions.Results:The expression of ODC in CAG with IM, DYS and GC was significantly higher than that in CSG(P<0.01).The expres-sion of c-myc was significantly higher in GC comparing with CSG and CAG with IM (P<0.01).In addition, ODC and c-myc positive immunostaining rates were significantly higher in poorly-differentiated GC than in well-differentiated GC (P<0.01).The expression of ODC was positively correlated with c-myc at different stages of gastric carcinogenesis.Conclusions:ODC may play an important role as carcinogenic factor, and c-myc promotes cell proliferation by inducing ODC expression.Detecting both markers together may help in ear-ly diagnosis of gastric carcinoma.%及蛋白的表达。结果:ODC mRNA及蛋白在萎缩性胃炎肠化生( CAG与IM)、不典型增生( DYS)及胃癌( GC)组织中的表达水平显著高于浅表性胃炎(CSG)(P<0.01)。 c-myc mRNA及蛋白在胃癌(GC)组织中的表达水平显著高于浅表性胃炎(CSG)、萎缩性胃炎肠化生(CAG with IM)(P<0.01),ODC和c-myc在中低分化腺癌的表达水平显著高于高分化腺癌(P<0.05)。 ODC与c-myc在胃粘膜癌变多阶段中的表达呈正相关( P<0.01)。结论:ODC作为致癌因子在胃癌发生中有重要作用,且c-myc通过促进ODC的

  19. Hepatocellular alterations and dysregulation of oncogenic pathways in the liver of transgenic mice overexpressing growth hormone.

    Science.gov (United States)

    Miquet, Johanna G; Freund, Thomas; Martinez, Carolina S; González, Lorena; Díaz, María E; Micucci, Giannina P; Zotta, Elsa; Boparai, Ravneet K; Bartke, Andrzej; Turyn, Daniel; Sotelo, Ana I

    2013-04-01

    Growth hormone (GH) overexpression throughout life in transgenic mice is associated with the development of liver tumors at old ages. The preneoplastic pathology observed in the liver of young adult GH-overexpressing mice is similar to that present in humans at high risk of hepatic cancer. To elucidate the molecular pathogenesis underlying the pro-oncogenic liver pathology induced by prolonged exposure to elevated GH levels, the activation and expression of several components of signal transduction pathways that have been implicated in hepatocellular carcinogenesis were evaluated in the liver of young adult GH-transgenic mice. In addition, males and females were analyzed in parallel in order to evaluate sexual dimorphism. Transgenic mice from both sexes exhibited hepatocyte hypertrophy with enlarged nuclear size and exacerbated hepatocellular proliferation, which were higher in males. Dysregulation of several oncogenic pathways was observed in the liver of GH-overexpressing transgenic mice. Many signaling mediators and effectors were upregulated in transgenic mice compared with normal controls, including Akt2, NFκB, GSK3β, β-catenin, cyclin D1, cyclin E, c-myc, c-jun and c-fos. The molecular alterations described did not exhibit sexual dimorphism in transgenic mice except for higher gene expression and nuclear localization of cyclin D1 in males. We conclude that prolonged exposure to GH induces in the liver alterations in signaling pathways involved in cell growth, proliferation and survival that resemble those found in many human tumors.

  20. Detection of gene amplification in MYCN, C-MYC, MYCL1, ERBB2, EGFR, AKT2, and human papilloma virus in samples from cervical smear normal cytology, intraepithelial cervical neoplasia (CIN I, II, III, and cervical cancer

    Directory of Open Access Journals (Sweden)

    Dabeiba Adriana García

    2011-06-01

    Full Text Available Introducción: El cáncer cervical es el segundo cáncer más importante en mujeres a nivel mundial y es la segunda causa de muerte por cáncer en mujeres. Se ha demostrado que el proceso de carcinogénesis cervical presenta componentes tanto genéticos como epigenéticos y medio ambientales. En la actualidad, hay gran interés en la búsqueda de marcadores moleculares asociados con la progresión de esta enfermedad, uno de los posibles mecanismos y que además está poco estudiado en cáncer cervical es la amplificación génica de algunos oncogenes como la familia MYC, EGFR y AKT entre otros. Objetivos: Detectar la amplificación génica de MYCN, C-MYC, MYCL1, ERBB2, EGFR y AKT2 además de la presencia del virus de papiloma humano en cepillados cervicales en mujeres con citología normal o con neoplasia intraepitelial cervical (NIC I, II y III o con cáncer cervical. Métodos: Se genotipificó mediante reverse line blot (RLB el virus de papiloma humano (VPH y se determinó el estado de amplificación génica de los genes mencionados mediante PCR en tiempo real utilizando sondas taqman. Resultados: El VPH se encontró presente en 4% de las pacientes con citología normal, en 48% en NIC I, 63.6% en NIC II, 64% en NIC III y 70.8% en cáncer cervical. Los genes MYCN, MYCL1 y ERBB2 mostraron mayor amplificación en lesiones de alto grado y cáncer con diferencias estadísticamente significativas  a las lesiones de bajo grado y citología normal, en 39.1%, 34.7% y 30.4% respectivamente. Además, se encontraron amplificados los genes C-MYC, EGFR y AKT2, en muestras de pacientes con cáncer cervical, en 12%, 18% y 13% respectivamente. Sin embargo, no se observaron diferencias estadísticamente significativas con respecto a las lesiones de alto y bajo grado y citología normal. Conclusión: En las lesiones de alto grado como en cáncer cervical, se encuentra mayor prevalencia del virus al igual que se detectan mayor cantidad de alteraciones gen

  1. Indole-3-carbinol induces cMYC and IAP-family downmodulation and promotes apoptosis of Epstein-Barr virus (EBV)-positive but not of EBV-negative Burkitt's lymphoma cell lines.

    Science.gov (United States)

    Perez-Chacon, Gema; de Los Rios, Cristobal; Zapata, Juan M

    2014-11-01

    Indole-3-carbinol (I3C) is a natural product found in broadly consumed plants of the Brassica genus, such as broccoli, cabbage, and cauliflower, which exhibits anti-tumor effects through poorly defined mechanisms. I3C can be orally administered and clinical trials have demonstrated that I3C and derivatives are safe in humans. In this study we show that I3C efficiently induces apoptosis in cell lines derived from EBV-positive Burkitt's lymphomas (virus latency I/II), while it does not have any cytotoxic activity against EBV-negative Burkitt's lymphomas and immortalized EBV-infected lymphoblastoid cell lines (virus latency III). The effect of I3C in EBV-positive Burkitt's lymphoma is very specific, since only I3C and its C6-methylated derivative, but not other 3-substituted indoles, have an effect on cell viability. I3C treatment caused apoptosis characterized by loss of mitochondria membrane potential and caspase activation. I3C alters the expression of proteins involved in the control of apoptosis and transcription regulation in EBV-positive Burkitt's lymphoma cell lines. Among those, cMYC, cIAP1/2 and XIAP downmodulation at mRNA and protein level precede apoptosis induction, thus suggesting a role in I3C cytotoxicity. We also showed that I3C and, more particularly, its condensation dimer 3,3'-diindolylmethane (DIM) prolonged survival and reduced tumor burden of mice xenotransplanted with EBV-positive Burkitt's lymphoma Daudi cells. In summary these results, together with previous reports from clinical trials indicating the lack of toxicity in humans of I3C and derivatives, support the use of these compounds as a new therapeutic approach for treating patients with endemic (EBV-positive) Burkitt's lymphoma.

  2. Hans, Choi immunophenotyping and C-MYC genetic features between pediatric and adult diffuse large B-cell lymphoma%儿童与成人弥漫大B细胞淋巴瘤的Hans、Choi免疫分型和C-MYC基因特征

    Institute of Scientific and Technical Information of China (English)

    徐红艳; 黄慧; 杨文萍; 黄传生; 钟梅慧

    2013-01-01

    Objective To explore the difference of Hans,Choi immunophenotyping and C-MYC gene characteristics between pediatric and adult diffuse large B-cell lymphoma.Methods To collect 60 cases of DLBCL clinicopathological data and follow-up,which contained 17 cases of children group,adult group of 43 patients.To observe CD10,BCL-6,MUM1,FOXP1,GCET1 and CD5 protein expression by immunohistochemical SP method and evaluated by Hans and Choi immunophenotyping standard genotyping.To detect C-MYC gene circumstances by interphase fluorescence insituhybridization (FISH).Results 1) Hans typing:the Children DLBCL group of GCB were 11 cases,non-GCB type were 6 cases; the GCB type in the adult DLBCL group were nine cases,non-GCB type were 34 cases.2)Choi typing:the Children DLBCL group of GCB type were 13 cases,ABC type were 4 cases; the adult DLBCL group of GCB type were 13 cases,ABC type were 30 cases (P < 0.01).3) C-MYC gene:The C-MYC gene disruption of children DLBCL were 5 cases; C-MYC gene in 43 adult cases were normal(P <0.01).Conclusions Child DLBCL of GCB-type with better prognosis while but non-GCB-type predict worse prognosis.The C-MYC gene disruption in Children DLBCL was significantly higher than that of adult ones.%目的 探讨弥漫大B细胞淋巴瘤(DLBCL)各年龄组的Hans、Choi免疫分型及C-MYC基因特征.方法 收集60例DLBCL临床病理资料并进行随访,其中儿童组17例、成人组43例.用免疫组化SP法观察CD10、BCL-6、MUM1、FOXP1、GCET1及CD5蛋白表达,根据Hans及Choi免疫分型标准分型;用间期荧光原位杂交法检测C-MYC 基因.结果 1)Hans分型:儿童DLBCL组GCB型11例,non-GCB型6例;成人组DLBCL中GCB型9例,non-GCB型34例(P<0.05).2) Choi分型:儿童DLBCL组GCB型13例,ABC型4例;成人DLBCL组GCB型13例,ABC型30例(P<0.01).3) C-MYC基因:儿童组DLBCL中C-MYC基因断裂6例;成人组DLBCL中C-MYC基因正常43例(P<0.01).结论 儿童DLBCL以GCB型为主,预后较好;成人DLBCL以non-GCB

  3. OVEREXPRESSION OF DOMINANT-NEGATIVE IRE1 ENZYME IN H1299-shE6AP CELLS INCREASES HEAT SHOCK ELEMENT-DEPENDENT TRANSCRIPTION

    Directory of Open Access Journals (Sweden)

    D. O.

    2015-12-01

    Full Text Available To investigate IRE1-dependent branch of endoplasmic reticulum stress pathway in various cancer cells we created cDNA-constructs for expression of dominant-negative inositol-requiring enzyme – 1 IRE1 and cytosolic domain of IRE1 fused on a C-terminus with c-Myc and 6xHis tags. The non-small-cell lung carcinoma cells H1299-shE6AP were transfected with these constructs. Using anti-c-Myc antibodies we demonstrated effective, dose-dependent expression of dominant-negative and cytosolic IRE1 proteins. In order to investigate IRE1-mediated, heat shock element-dependent transcription, the cells were further transfected with a reporter construct containing heat shock element. We observed that overexpression of dnIRE1 in H1299-shE6AP cells led to significant induction of heat shock element-dependent transcription. This observation may reflect the induction of heat shock genes, which contribute to cellular adaptation to inhibition of native IRE1, a key sensory-signaling enzyme of endoplasmic reticulum stress pathway, which suppresses cancer cell proliferative capacities and alternates the expression of numerous genes, including many transcription factors.

  4. Cloning and Preliminary Function Analysis of Xuhuai Goat c-Myc Promoter%徐淮山羊c-Myc基因启动子的克隆及其功能的初步分析

    Institute of Scientific and Technical Information of China (English)

    韦光辉; 左其生; 李东; 张亚妮; 刘志永; 朱睿; 邱峰龙; 李碧春

    2014-01-01

    本研究旨在确定徐淮山羊c-Myc基因启动子区域,找出该基因启动子的核心调控区,初步探讨c-Myc基因的表达调控机制.根据UCSC基因组数据库已公布的绵羊c-Myc基因的启动子序列,设计特异性PCR引物扩增c-Myc基因的一系列启动子缺失片段,定向克隆至pEGFP-N1和PGL3-c-Myc,分别转染gFF、COS7及P19细胞,并进行TSA和NFAT1诱导,同时对-402~-249 bp区域的转录因子SP1结合位点进行定点突变,最后进行双荧光报告基因活性检测.结果表明,徐淮山羊c-Myc基因5′侧翼区-1 334~+1 bp区域的启动子活性最强,-402~+1 bp区域为c-Myc基因启动子基本活性区域.进一步研究发现,-1 334~-971 bp、-587~-147 bp区域存在正调控元件,-1 976~-1 334 bp、-971~-587 bp区域存在负调控元件.TSA和NFAT1均能增强PMyc启动子的活性,SP1结合位点定点突变后,启动子活性降低.本试验通过构建包含c-Myc基因启动子不同片段的重组报告基因载体并比较其转录活性,确定了c-Myc基因启动子的核心区域,发现转录因子SP1是c-Myc基因启动子核心区域的调控元件,为进一步研究c-Myc基因的表达调控机制奠定了基础.

  5. Clinical course of incidental syringomyelia without predisposing pathologies.

    Science.gov (United States)

    Kim, Jiha; Kim, Chi Heon; Jahng, Tae-Ahn; Chung, Chun Kee

    2012-05-01

    Although the widespread use of MRI has facilitated the diagnosis of subclinical syringomyelia, little information has been established regarding its natural course. To elucidate the clinical course and treatment strategy of incidental syringomyelia without predisposing pathologies, we retrospectively reviewed the clinical course of 12 adult patients with incidental syringomyelia. No patients had any predisposing pathology, including Chiari malformation or spinal cord tumor. Using the medical records and MRI, we analyzed the neurological and radiological features of each patient. After a mean of 39.9 months follow-up, no patient developed neurological deterioration. Although one patient had radiological progression without neurological deterioration, 11 patients (91.7%) had no change on MRI. Additionally, all patients experienced a favorable clinical course without surgery. These results indicate that, for patients with incidental syringomyelia without predisposing pathology, close observation rather than surgery can be recommended.

  6. Detecting disease-predisposing variants: The haplotype method

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, A.M.; Thomson, G. [Univ. of California, Berkeley, CA (United States)

    1997-03-01

    For many HLA-associated diseases, multiple alleles - and, in some cases, multiple loci - have been suggested as the causative agents. The haplotype method for identifying disease-predisposing amino acids in a genetic region is a stratification analysis. We show that, for each haplotype combination containing all the amino acid sites involved in the disease process, the relative frequencies of amino acid variants at sites not involved in disease but in linkage disequilibrium with the disease-predisposing sites are expected to be the same in patients and controls. The haplotype method is robust to mode of inheritance and penetrance of the disease and can be used to determine unequivocally whether all amino acid sites involved in the disease have not been identified. Using a resampling technique, we developed a statistical test that takes account of the nonindependence of the sites sampled. Further, when multiple sites in the genetic region are involved in disease, the test statistic gives a closer fit to the null expectation when some - compared with none - of the true predisposing factors are included in the haplotype analysis. Although the haplotype method cannot distinguish between very highly correlated sites in one population, ethnic comparisons may help identify the true predisposing factors. The haplotype method was applied to insulin-dependent diabetes mellitus (IDDM) HLA class II DQA1-DQB1 data from Caucasian, African, and Japanese populations. Our results indicate that the combination DQA1 No. 52 (Arg predisposing) DQB1 No. 57 (Asp protective), which has been proposed as an important IDDM agent, does not include all the predisposing elements. With rheumatoid arthritis HLA class H DRB1 data, the results were consistent with the shared-epitope hypothesis. 35 refs., 2 figs., 6 tabs.

  7. 流体切应力对脑动静脉畸形内皮细胞增殖与c-myc表达的影响%Effect of flow shear stress on endothelial cell proliferation and c-myc expression in cerebral arteriovenous malformation

    Institute of Scientific and Technical Information of China (English)

    赵明光; 李彦兵; 吕博川; 梁勇; 薛洪利; 赵丽萍; 王丹玲

    2007-01-01

    BACKGROUND:Shear stress can directly mediate the expression of endothelial cells, especially some cytokine genes whose codes are related to angiogenesis. Otherwise, flow shear stress of blood plays an importantly biological role in regulating vascular structure and function.OBJECTIVE: To observe the effects of laminar flow shear stress on the proliferation of vascular endothelial cells and the expression of protooncogene c-myc in human cerebral arteriovenous malformation.DESIGN: Randomized controlled study.SETTING: Department of Neurosurgery, Shenyang General Hospital of Military Area Command of Chinese PLA.MATERIALS: The experiment was carried out in the Neuromedical Institute, General Hospital of Shenyang Military Area Command of Chinese PLA from November 2006 to February 2007. Fresh samples of human cerebral arteriovenous malformation were derived from 20 patients who were of grade Spetzler Ⅱ -Ⅲ and received resection of human cerebral arteriovenous malformation in the Department of Neurosurgery, General Hospital of Shenyang Military Area Command of Chinese PLA in 2006. All cases were diagnosed with whole-brain angiography before operation. The main reagents and equipments were detailed as follows: M199 culture media (Gilbco BRL), quality fetal bovine serum (HyClone), endothelial cell growth supplement (ECGS; Sigma, USA), CO2 incubator (Forma Scientific, USA), flow cytometry analysis of cell cycle kit (BD Company), flow cytometer (FACS Calibur, BD Company), rat-anti-human c-myc monoclonal antibody (Santa Cruz Company, USA), and reverse transcription polymerase chain reaction (RT-PCR) kit (Promega).METHODS: Tissue explants adherent method was used to culture vascular endothelial cells of human cerebral arteriovenous malformation, and then the cells were classified into 4 groups based on degree of shear stress, including control group, low shear stress group, moderate shear stress group and high shear stress group. Cultured endothelial cells of human cerebral

  8. The prevalence of predisposing deformity in osteoarthritic hip joints

    DEFF Research Database (Denmark)

    Klit, Jakob; Gosvig, Kasper; Jacobsen, Steffen;

    2011-01-01

    relationship in both sexes with the clinical presentation. The study cohort which fulfilled these inclusion criteria consisted of 322 females (149 right hips and 173 left hips) and 162 males (77 right hips and 85 left hips) with osteoarthritis. We found an overall prevalence of predisposing hip deformities...... in females of 62.4% and in males of 78.9%. Minor and major deformities showed the same prevalence. Both sexes had a comparable prevalence of minor and major hip joint deformity, except for pistol grip deformity, which was more prevalent in men. We concluded that 'idiopathic osteoarthritis' is uncommon......, and that even minor predisposing deformities are associated with hip osteoarthritis....

  9. Dendrosomal nanocurcumin and p53 overexpression synergistically trigger apoptosis in glioblastoma cells

    Directory of Open Access Journals (Sweden)

    Reihaneh Keshavarz

    2016-12-01

    Full Text Available Objective(s: Glioblastoma is the most lethal tumor of the central nervous system. Here, we aimed to evaluate the effects of exogenous delivery of p53 and a nanoformulation of curcumin called dendrosomal curcumin (DNC, alone and in combination, on glioblastoma tumor cells. Materials and Methods: MTT assay was exploited to measure the viability of U87-MG cells against DNC treatment. Cells were separately subjected to DNC treatment and transfected with p53-containing vector and then were co-exposed to DNC and p53 overexpression. Annexin-V-FLUOS staining followed by flow cytometry and real-time PCR were applied to examine apoptosis and analyze the expression levels of the genes involved in cell cycle and oncogenesis, respectively. Results: The results of cell viability assay through MTT indicated that DNC inhibits the proliferation of U87-MG cells in a time- and dose-dependent manner. Apoptosis evaluation revealed that p53 overexpression accompanied by DNC treatment can act in a synergistic manner to significantly enhance the number of apoptotic cells (90% compared with their application alone (15% and 38% for p53 overexpression and DNC, respectively. Also, real-time PCR data showed that the concomitant exposure of cells to both DNC and p53 overexpression leads to an enhanced expression of GADD45 and a reduced expression of NF-κB and c-Myc. Conclusion: The findings of the current study suggest that our combination strategy, which merges two detached gene (p53 and drug (curcumin delivery systems into an integrated platform, may represent huge potential as a novel and efficient modality for glioblastoma treatment.

  10. Iron deficiency: an overlooked predisposing factor in angular cheilitis.

    Science.gov (United States)

    Murphy, N C; Bissada, N F

    1979-10-01

    Clinicians who recommend the use of antifungal agents for angular cheilitis may be treating the symptoms and not the predisposing cause of the disease. Iron deficiency should be considered as part of the differential diagnosis whenever angular cheilitis is encountered, especially in women of child-bearing age.

  11. In vivo study on the effects of microcystin extracts on the expression profiles of proto-oncogenes (c-fos, c-jun and c-myc) in liver, kidney and testis of male Wistar rats injected i.v. with toxins.

    Science.gov (United States)

    Li, Huiying; Xie, Ping; Li, Guangyu; Hao, Le; Xiong, Qian

    2009-01-01

    Microcystins (MCs) are a potent liver tumor promoter, possessing potent tumor-promoting activity and weak initiating activity. Proto-oncogenes are known to be involved in the tumor-promoting mechanisms of microcystin-LR. However, few data are available on the effects of MCs on proto-oncogenes in the whole animal. To investigate the effects of MCs on the expression profile of the proto-oncogenes in different organs, male Wistar rats were injected intravenously with microcystin extracts at a dose of 86.7 mug MC-LR eq/kg bw (MC-LR eq, MC-LR equivalents). mRNA levels of three proto-oncogenes c-fos, c-jun and c-myc in liver, kidney and testis were analyzed using quantitative real-time PCR at several time points post-injection. Significant induction of these genes at transcriptional level was observed in the three organs. In addition, the increase of mRNA expression of all three genes was much higher in liver than in kidney and testis. Meanwhile, the protein levels of c-Fos and c-Jun were investigated by western blotting. Both proteins were induced in the three organs. However, elevations of protein levels were much lower than those of mRNA levels. These findings suggest that the expression of c-fos, c-jun and c-myc might be one possible mechanism for the tumor-promoting activity and initiating activity of microcystins.

  12. Expression and significance of AP-2α,Bcl-2 and C-myc in severe preeclampsia%AP-2α、Bcl-2及C-myc在重度子痫前期患者胎盘组织中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    张玲; 曾宪旭; 张展; 常爱民

    2016-01-01

    目的:探讨转录因子激活蛋白-2α( AP-2α)与B淋巴细胞瘤-2基因( Bcl-2)、C-myc在重度子痫前期胎盘组织中的表达及其意义。方法采用免疫组化法及实时荧光定量-PCR( RT-PCR)的方法,检测重度子痫前期组胎盘组织及正常对照组胎盘组织中AP-2α及Bcl-2、C-myc蛋白及mRNA的表达。结果重度子痫前期组胎盘组织中AP-2α蛋白明显高于正常对照组(P﹤0.05),Bcl-2和C-myc蛋白表达明显低于正常对照组(P﹤0.05);重度子痫前期组胎盘组织中AP-2α mRNA明显高于正常对照组(P﹤0.05),C-myc和Bcl-2 mRNA表达明显低于正常对照组( P﹤0.05)。结论 AP-2α和Bcl-2、C-myc在重度子痫前期患者胎盘组织中的差异表达参与重度子痫前期的病理生理过程。%Objective To investigate the role of AP-2α,Bcl-2 and C-myc proein and mRNA in severe preeclampsia. Methods The expression of AP-2α,Bcl-2 and C-myc in placental tissues in se-vere preeclamptic pregnancies and normotensive pregnancies were analyzed by using immunohistochemis-try and RT-PCR. Results The positive expression of AP-2α for placenta trophoblast in severe pre-eclampsia was significantly higher than that in control group( P﹤0. 05 ),while the positive expressions of Bcl-2 and C-myc were significantly lower than those in control group( P﹤0. 05 ). The expression of AP-2αmRNA for placenta tissue in severe preeclampsia was significantly higher than that in control group ( P﹤0. 05 ),while the expressions of Bcl-2 and C-myc mRNA were significantly lower than those in con-trol group( P﹤0. 05 ). Conclusions AP-2αand Bcl-2 ,C-myc participate in the pathological process of preeclampsia.

  13. POLE mutations in families predisposed to cutaneous melanoma

    DEFF Research Database (Denmark)

    Aoude, Lauren G; Heitzer, Ellen; Johansson, Peter

    2015-01-01

    Germline mutations in the exonuclease domain of POLE have been shown to predispose to colorectal cancers and adenomas. POLE is an enzyme involved in DNA repair and chromosomal DNA replication. In order to assess whether such mutations might also predispose to cutaneous melanoma, we interrogated...... whole-genome and exome data from probands of 34 melanoma families lacking pathogenic mutations in known high penetrance melanoma susceptibility genes: CDKN2A, CDK4, BAP1, TERT, POT1, ACD and TERF2IP. We found a novel germline mutation, POLE p.(Trp347Cys), in a 7-case cutaneous melanoma family....... Functional assays in S. pombe showed that this mutation led to an increased DNA mutation rate comparable to that seen with a Pol ε mutant with no exonuclease activity. We then performed targeted sequencing of POLE in 1243 cutaneous melanoma cases and found that a further ten probands had novel or rare...

  14. Predisposing factors and prevention of Clostridium perfringens-associated enteritis.

    Science.gov (United States)

    Allaart, Janneke G; van Asten, Alphons J A M; Gröne, Andrea

    2013-09-01

    Clostridium perfringens is one of the major causes of intestinal disease in humans and animals. Its pathogenicity is contributed to by the production of a variety of toxins. In addition, predisposing environmental factors are important for the induction of C. perfringens-associated enteritis as shown by infection models. Environmental contamination, gastric and intestinal pH, intestinal microflora, nutrition, concurrent infections, and medical interventions may influence the intestinal colonization, growth, and toxin production by C. perfringens. Prevention of C. perfringens-associated enteritis may be mediated by the use of feed additives like probiotics, prebiotics, organic acids, essential oils, bacteriophages, lysozymes, bacteriocins, and antimicrobial peptides. Here we summarize and discuss published data on the influence of different environmental predisposing factors and preventive measures. Further research should focus on feed composition and feed additives in order to prevent C. perfringens-associated enteritis.

  15. Predisposing factors and surgical outcome of complicated liver hydatid cysts

    Institute of Scientific and Technical Information of China (English)

    Alper; Akcan; Erdogan; Sozuer; Hizir; Akyildiz; Zeki; Yilmaz; Ahmet; Ozturk; Altay; Atalay

    2010-01-01

    AIM: To evaluate the predisposing factors for peritoneal perforation and intrabiliary rupture and the effects of these complications on surgical outcome in liver hydatid disease.METHODS: A total of 372 patients with liver hydatid cysts who had undergone surgical treatment were evaluated retrospectively. Twenty eight patients with peritoneal perforation, 93 patients with spontaneous intrabiliary perforation, and 251 patients with noncomplicated hydatid cysts were treated in our clinics.RESULTS: When the pred...

  16. Depressive behavior induced by social isolation of predisposed female rats.

    Science.gov (United States)

    Zanier-Gomes, Patrícia Helena; de Abreu Silva, Tomaz Eugênio; Zanetti, Guilherme Cia; Benati, Évelyn Raquel; Pinheiro, Nanci Mendes; Murta, Beatriz Martins Tavares; Crema, Virgínia Oliveira

    2015-11-01

    Depression is a mood disorder that is more prevalent in women and has been closely associated with chronic stress. Many models of depression have been suggested that consider different forms of stress. In fact, stress is present in the life of every human being, but only a few develop depression. Accordingly, it seems wrong to consider all stressed animals to be depressed, emphasizing the importance of predisposition for this mood disorder. Based on this finding, we evaluated a predisposition to depressive behavior of female rats on the forced swim test (FST), and the more immobile the animal was during the FST, the more predisposed to depression it was considered to be. Then, animals were subjected to the stress of social isolation for 21 days and were re-evaluated by the FST. The Predisposed/Isolated rats presented higher immobility times. Once all the rats had prior experience in the FST, we calculated an Index of Increase by Isolation, confirming the previous results. Based on this result, we considered the Predisposed/Isolated group as presenting depressive behavior ('Depressed') and the Nonpredisposed/Nonisolated group as the control group ('Nondepressed'). The animals were distributed into 4 new groups: Nondepressed/Vehicle, Nondepressed/Amitriptyline, Depressed/Vehicle, Depressed/Amitriptyline. After 21 days of treatment, only the Depressed/Vehicle group differed from the other 3 groups, demonstrating the efficacy of amitriptyline in treating the depressive behavior of the Depressed animals, validating the model. This study shows that conducting an FST prior to any manipulation can predict predisposition to depressive behavior in female rats and that the social isolation of predisposed animals for 21 days is effective in inducing depressive behavior. This behavior can be considered real depressive behavior because it takes into account predisposition, chronic mild stress, and the prevalent gender.

  17. Effects of valsartan and spironolactone on the expression of c-myc in the left ventricle of renovascular hypertension rats.%缬沙坦与螺内酯对肾血管性高血压大鼠左室c-myc表达的影响

    Institute of Scientific and Technical Information of China (English)

    王圣; 刘宇飞; 曲鹏

    2011-01-01

    Objective To assess the roles of the local renin-angiotensin-aldosterone system (RAAS) and mechanical load in the expression of c-myc in hypertrophied myocardium of hypertension. Methods Two-kidney,one-clip (2KlC) renovascular hypertension was induced in Sprague-Dawley rats. The rats were randomized into untreated hypertension group (H group), spironolactone group (gorged spironolactone 50 mg/kg·day, S group), valsartan group (gorged valsanan 30 mg/kg·day, V group), and spironolactone plus valsartan group (gorged spironolactone 50 mg/kg·day and valsartan 30m g/kg·day at the same time, S+V group). Sham-operated rats served as controls (C group). The changes of heart structure and function in all groups were observed with echocardiogram. Left ventricle concentration of angiotensin Ⅱ(Ang Ⅱ) and ALD was assessed by radioimmunoassay. Immunohistochemistry was adopted to examine the protein expression of c-myc. Results After 8 weeks treatment, carotid systolic pressure, .MESS (meridian end systolic stress), LVPWd(left ventricular posterior wall thickness at end diastolic), IVSd (interventricular septal thickness at end diastolic) in V group and S-V group were decreased significantly compared with those in H group and S group (P<0.05). The left ventricle concentration of Ang Ⅱ was much lower in S group, V group and S-V group than that in It group (p<0.05). The expression of c-myc was much higher in H group and S group than that in C group, V group and S+V group (P<0.01). The expression of c-myc was positively related to carotid systolic pressure after 8 weeks treatment (r=0.848, P<0.01). Significant correlation was also present between MESS and the expression of c-myc (r=0.580,P<0.01). No correlation was found between Ang Ⅱ and the expression ofc-myc. Conclusion The increasing of mechanical load is an important factor inducing the persistent expression of c-myc in left ventricle cardiomyocytes of renovascular hypertension rats. The persistent

  18. 伽玛射线诱导脑膜瘤细胞凋亡和影响原癌基因c-myc的表达%Effects of gamma-ray on apoptosis and expression of c-myc protooncogene of meningioma cells

    Institute of Scientific and Technical Information of China (English)

    陈春美; 陈建乐; 韦浩; 张伟强; 蔡刚峰; 王春华; 王锐; 石松生; 杨卫忠

    2013-01-01

    目的 观察不同剂量伽玛(γ)射线诱导脑膜瘤细胞凋亡和原癌基因c-myc表达变化.方法 采用机械分离法获得稳定生长脑膜瘤细胞的离体培养细胞株,根据不同照射剂量分为4组,照射组分别接受中心剂量为2.00、5.00、8.22、13.33 Gy,设立对照组,剂量为0,照射后荧光显微镜观察细胞形态变化,流式细胞术检测细胞周期和凋亡率,Westem blot法检测c-myc蛋白的表达变化.结果 对照组、照射1组、2组、3组及4组细胞凋亡率分别为:(3.73±0.25)%、(4.07±0.29)%、(9.81±1.66)%、(21.63±3.08)%、(8.27±1.61)%;c-myc蛋白表达分别为:0、11±0.01、0.12±0.01、0.19 ±0.02、0.31±0.08、0.09±0.01;对照组和中心剂量2 Gy组照射后细胞形态、细胞周期、凋亡率和c-myc蛋白表达差异无统计学意义(P>0.05);中心剂量分别为5.00 Gy和8.22 Gy组细胞出现凋亡特征,细胞周期G0/G1和G2/M期细胞数量逐渐增多,细胞凋亡率升高,c-myc蛋白表达增多,与对照组比较差异均有统计学意义(P<0.05);剂量为13.33 Gy组,细胞以坏死为主,S期细胞增多,c-myc蛋白表达减少.结论 一定剂量的伽玛刀射线能够诱导脑膜瘤细胞进入凋亡,原癌基因c-myc在此过程中可能发挥促进脑膜瘤细胞进入凋亡过程.%Objective To investigate the apoptosis of meningioma cell and changes of the expression of c-myc protooncogene after gama ray radiation.Methods The isolated and cultured meningioma cells with stable growth were obtained from a patient with meningiomas by mechanical separation,and those cells were divided into 4 groups with the radiation center doses of 2.00,5.00,8.22,and 13.33 Gy respectively.There was a control group without radiation.Meningioma cell morphology was observed under fluorescent microscope.Flow cytometry was used to examine the cell cycle and apoptosis.The expression of c-myc protein was detected by using Western blotting.Results The cell apoptosis rate in

  19. MAT2A mutations predispose individuals to thoracic aortic aneurysms.

    Science.gov (United States)

    Guo, Dong-chuan; Gong, Limin; Regalado, Ellen S; Santos-Cortez, Regie L; Zhao, Ren; Cai, Bo; Veeraraghavan, Sudha; Prakash, Siddharth K; Johnson, Ralph J; Muilenburg, Ann; Willing, Marcia; Jondeau, Guillaume; Boileau, Catherine; Pannu, Hariyadarshi; Moran, Rocio; Debacker, Julie; Bamshad, Michael J; Shendure, Jay; Nickerson, Deborah A; Leal, Suzanne M; Raman, C S; Swindell, Eric C; Milewicz, Dianna M

    2015-01-08

    Up to 20% of individuals who have thoracic aortic aneurysms or acute aortic dissections but who do not have syndromic features have a family history of thoracic aortic disease. Significant genetic heterogeneity is established for this familial condition. Whole-genome linkage analysis and exome sequencing of distant relatives from a large family with autosomal-dominant inheritance of thoracic aortic aneurysms variably associated with the bicuspid aortic valve was used for identification of additional genes predisposing individuals to this condition. A rare variant, c.1031A>C (p.Glu344Ala), was identified in MAT2A, which encodes methionine adenosyltransferase II alpha (MAT IIα). This variant segregated with disease in the family, and Sanger sequencing of DNA from affected probands from unrelated families with thoracic aortic disease identified another MAT2A rare variant, c.1067G>A (p.Arg356His). Evidence that these variants predispose individuals to thoracic aortic aneurysms and dissections includes the following: there is a paucity of rare variants in MAT2A in the population; amino acids Glu344 and Arg356 are conserved from humans to zebrafish; and substitutions of these amino acids in MAT Iα are found in individuals with hypermethioninemia. Structural analysis suggested that p.Glu344Ala and p.Arg356His disrupt MAT IIα enzyme function. Knockdown of mat2aa in zebrafish via morpholino oligomers disrupted cardiovascular development. Co-transfected wild-type human MAT2A mRNA rescued defects of zebrafish cardiovascular development at significantly higher levels than mRNA edited to express either the Glu344 or Arg356 mutants, providing further evidence that the p.Glu344Ala and p.Arg356His substitutions impair MAT IIα function. The data presented here support the conclusion that rare genetic variants in MAT2A predispose individuals to thoracic aortic disease.

  20. 聚乙烯亚胺介导BmkCT基因抑制C6胶质瘤细胞C-Myc、VEGF表达%Expression of Polyethyleneimine-mediated Bmk CT Gene Inhibitation to VEGF and C-Myc in C6 Glioma Cells

    Institute of Scientific and Technical Information of China (English)

    张亚涛; 范丽娜; 温春丽; 胡风云

    2016-01-01

    目的:应用阳离子聚合物聚乙烯亚胺(polyethyleneimine,PEI)介导东亚钳蝎氯离子通道毒素( Buthus martensii Karsch Chlorotoxin-like Toxin,Bmk CT)基因转染 C6胶质瘤细胞,观察其对 C6细胞内 C-Myc、VEGF 表达的影响。方法:将 PEI 分别和 pEGFP-N1-Bmk CT、pEGFP-N1质粒混合,获得 PEI / pEGFP-N1-Bmk CT 和 PEI / pEG-FP-N1两种复合物,将其转染 C6细胞,MTS 法观察细胞增殖和存活活力,48 h后通过 Western-blot 方法检测 C-Myc、VEGF 蛋白表达水平。结果:PEI / pEGFP-N1-Bmk CT 转染 C6细胞48 h后较 PEI / pEGFP-N1能够显著抑制C6细胞增殖和存活活力,同时抑制 C-Myc、VEGF 蛋白表达。结论:PEI / pEGFP-N1-Bmk CT 转染 C6细胞可能通过抑制 C-Myc、VEGF 表达进而抑制 C6细胞增殖和血管生成。%Objective:To investigate the effects of PEI(polyethyleneimine)-mediated Bmk CT(Buthus martensii Karsch Chlorotoxin-like Toxin),Bmk CT gene transfection on the expression levels of C-Myc and VEGF of C6 glioma cells. Methods:pEGFP-N1 and pEGFP-N1-BmK CT were combined with PEI to form the composites,PEI/ pEGFP-N1-Bmk CT and PEI/ pEGFP-N1,which were used to transfect C6 glioma cells. Then,MTS test was performed to investigate the proliferation and viability of the transfected cells. After 48 hours the expression of C-Myc and VEGF proteins were de-tected by Western-bloting. Results:The proliferation of C6 glioma cells in the pEGFP-N1-Bmk CT group was significant-ly inhibited,while the expression levels of C-Myc and VEGF were lower than pEGFP-N1 group after the transfection. Conclusion:PEI/ pEGFP-N1-Bmk CT may suppress the angiogenesis and the proliferation of C6 glioma cells through in-hibiting the expression of C-Myc and VEGF.

  1. Mitogenic signaling pathways in the liver of growth hormone (GH)-overexpressing mice during the growth period.

    Science.gov (United States)

    Martinez, Carolina S; Piazza, Verónica G; González, Lorena; Fang, Yimin; Bartke, Andrzej; Turynl, Danie; Miquet, Johanna G; Sotelo, Ana I

    2016-01-01

    Growth hormone (GH) is a pleiotropic hormone that triggers STATs, ERK1/2 and Akt signaling, related to cell growth and proliferation. Transgenic mice overexpressing GH present increased body size, with a disproportionate liver enlargement due to hypertrophy and hyperplasia of the hepatocytes. We had described enhanced mitogenic signaling in liver of young adult transgenic mice. We now evaluate the activation of these signaling cascades during the growth period and relate them to the morphological alterations found. Signaling mediators, cell cycle regulators and transcription factors involved in cellular growth in the liver of GH-overexpressing growing mice were assessed by immunoblotting, RT-qPCR and immunohistochemistry. Hepatocyte enlargement can be seen as early as 2-weeks of age in GH-overexpressing animals, although it is more pronounced in young adults. Levels of cell cycle mediators PCNA and cyclin D1, and transcription factor c-Jun increase with age in transgenic mice with no changes in normal mice, whereas c-Myc levels are higher in 2-week-old transgenic animals and cyclin E levels decline with age for both genotypes. STAT3, Akt and GSK3 present higher activation in the adult transgenic mice than in the growing animals, while for c-Src and mTOR, phosphorylation in GH-overexpressing mice is higher than in control siblings at 4 and 9 weeks of age. No significant changes are observed for ERK1/2, neither by age or genotype. Thus, the majority of the mitogenic signaling pathways are gradually up-regulated in the liver of GH-transgenic mice, giving rise to the hepatic morphological changes these mice exhibit.

  2. Clinical significance of bcl-6, p53, c-myc aberrations in diffuse large B-cell lymphoma%bcl-6、p53、c-myc基因异常在弥漫大B细胞淋巴瘤中的临床意义

    Institute of Scientific and Technical Information of China (English)

    何兰兰; 严峰; 刘德亮; 曹祥山; 谢晓宝; 王志林

    2013-01-01

    Objective To investigate aberrations of bcl-6,p53,c-myc genes in diffuse large B-cell lymphoma (DLBCL) and its clinical significance.Methods Interphase fluorescence in situ hybridization (I-FISH) was detected in 59 DLBCL patients in vivo tissue bcl-6,p53 protein,c-myc gene status.The patients were treated with CHOP or R-CHOP chemotheralpy,and the survival rates and treatment efficiency were compared.Results The p53 deletion was detected in 18 of the 59 cases (30.5 %),bcl-6 rearrangement in 11 cases (18.6 %),5 cases with c-myc rearrangement (8.5 %).In the aspects of remission rate,p53 deletion positive group contained less advantage than negative ones (33.3 % vs 75.6 %,x2 =9.560,P =0.002).The prognosis of bcl-6 gene rearrangement positive group different from negative group,but the difference was not statistically significant (OS,P =0.107; PFS,P =0.094),p53 deletion positive patients was in significantly worse prognosis than the negative group (OS,P =0.031; PFS,P =0.028),c-myc rearrangement positive group difference in gene rearrangement negative group,but the difference was not statistically significant (OS,P =0.163; PFS,P =0.167).In the CHOP group,prognosis of p53 deletion,c-myc rearrangement positive group were significantly worse than the negative group,the difference was statistically significant (P < 0.05).In R-CHOP group,the prognostic significance of bcl-6 gene rearrangement positive group were worse (OS,P =0.003; PFS,P =0.007).Conclusion DLBCL patients with bcl-6,p53,c-myc genes aberrations are related with poor prognosis,and they can be used as prognostic factors for predicting DLBCL and guiding therapy.%目的 探讨bcl-6 、p53、c-myc基因异常的检测在弥漫大B细胞淋巴瘤(DLBCL)中的临床意义.方法 间期荧光原位杂交(I-FISH)方法检测59例DLBCL患者活体石蜡组织bcl-6、p53蛋白、c-myc基因异常的情况,同时以CHOP及R-CHOP方案化疗,评价疗效.观察bcl-6、p53蛋白、c-myc基因与化疗疗

  3. Quercetin通过TGF-β1/smad3/c-myc信号通路对LOVO细胞增殖的抑制作用%Quercetin inhibits proliferation of LOVO cells through TGF-β1/smad3 / c-myc signaling pathway

    Institute of Scientific and Technical Information of China (English)

    安昌勇; 寇耀; 赵林; 邵新宏; 张刘平; 张才全

    2013-01-01

    Objective To investigate the effect of Quercetin on TlGF-βl/smad3/c-myc signating pamway of LO V O cell strain as well as the possible mechanisms of inhibitory effect of Quercetin on the proliferation of LOVO cells.Methods Lovo ceils were treated with Quercetin at dosages of 5,10,20,40,80 and 160 μmol / L for 48 h respectively,using those untreated as control,and determined for proliferation activity.LOVO cells were divided into C,T,TQ and Q groups.The cells in C group were untreated,while those in T group were treated with 5 ng/ml TGF-β1 for one week,those in TQ group with 5 ng/ml TGF-β1 for one week then with 20 μmol/L Quercetin for 72 h,and those in Q group with 20 μmol/L Quercetin for 72 h.The effects of Quercetin and TGF-β1 on the clone formation ability as well as expressions of smad3 and c-myc were analyzed by plate clone formation test,immunohistochemical assay with SP staining,RT-PCR and Western blot.Results Quercetin showed significantly dosage-dependent inhibitory effect on proliferation of LOVO cells,with an IC50 of about 40 μmol/L.The proliferation of LOVO cells as well as expressions of smad3 and c-myc were promoted by TGF-β1 significantly (P < O.05),while were inhibited by Quercetin significantly (P < 0.05).As compared with those in TQ group,both the proliferation ability and the expression level of c-myc in TQ group decreased significantly(P < 0.05).Conclusion Quercetin down-regulated the expression of target gene c-myc by inhibiting the TGF-β1/smad3/c-myc signaling pathway,and inhibited the proliferation of LOVO cells.%目的 研究Quercetin对结肠癌LOVO细胞株TGF-β1/smad3/c-myc信号通路的影响,并探讨其抑制LOVO细胞增殖的可能机制.方法 采用5、10、20、40、80、160 μmol/L的Quercetin处理结肠癌LOVO细胞48 h,以未经Quercetin处理的LOVO细胞作为对照组,采用MTT法检测Quercetin对细胞增殖活力的影响.以5 ng/ml的TGF-Bl刺激l周的LOVO细胞为细胞模型,设对照

  4. Subclinical Mastitis in Dairy Animals: Incidence, Economics, and Predisposing Factors

    Directory of Open Access Journals (Sweden)

    Mukesh Kr. Sinha

    2014-01-01

    Full Text Available A study was conducted to assess the incidence and economics of subclinical form of bovine mastitis in Central Region of India. Daily milk records of 187 animals during three seasons were collected and subjected to analysis. The economic loss due to reduction in yield, clinical expenses, and additional resources used were quantified and aggregated. The losses due to mastitis in monetary terms were estimated to be INR1390 per lactation, among which around 49% was owing to loss of value from milk and 37% on account of veterinary expenses. Higher losses were observed in crossbred cows due to their high production potential that was affected during mastitis period. The cost of treating an animal was estimated to be INR509 which includes cost of medicine (31.10% and services (5.47%. Inadequate sanitation, hygiene, and veterinary services were the main predisposing factors for incidence and spread of mastitis as perceived by the respondents.

  5. 通脉汤方对实验性动脉粥样硬化家兔胸主动脉表皮生长因子受体和c-myc基因表达的影响%Effect of Tongmai Recipe on Epidermal Growth Factor Receptor and Protooncogene c-myc mRNA Expression in Aorta of Atherosclerotic Rabbit

    Institute of Scientific and Technical Information of China (English)

    张娟; 孙明; 周宏研

    2007-01-01

    目的 探讨通脉方对实验性动脉粥样硬化家兔胸主动脉表皮生长因子受体和c-myc基因表达的影响.方法 日本大耳白兔40只,随机分为4组:①对照组10只,以普通饲料喂养,每日两次;②模型组10只,以高胆固醇饲料[胆固醇0.5 g/(kg·d)、蛋黄2 g/(kg·d)和猪油2 g/(kg·d)]喂养,每日两次;③通脉汤方低剂量组(简称低剂量组)10只,高胆固醇饲料喂养(剂量同模型组),同时予通脉汤方灌胃,每只剂量相当于生药7.3 g/(kg*d),分上下午两次给药;④通脉汤方高剂量组(简称高剂量组)10只,高胆固醇饲料喂养(剂量同模型组),同时予通脉汤方灌胃,每只剂量相当于生药21.9 g/(kg·d),分上下午两次给药;共喂养16周.运用免疫组织化学染色法检测主动脉表皮生长因子受体的表达,同时用内参比逆转录聚合酶链反应定量分析c-myc mRNA在主动脉的表达.结果 模型组主动脉表皮生长因子受体及c-myc mRNA表达显著高于对照组(分别为0.327±0.030比0.209±0.006,P0.05;0.44±0.09比0.52±0.11 P>0.05).结论 ①动脉粥样硬化时促进血管平滑肌细胞增殖的表皮生长因子受体及原癌基因c-myc mRNA表达增强.②通脉汤方通过抑制血管壁表皮生长因子受体及c-myc基因的表达,从而抑制血管平滑肌细胞增殖.

  6. Inverse association between obesity predisposing FTO genotype and completed suicide.

    Directory of Open Access Journals (Sweden)

    Izabela Chojnicka

    Full Text Available The A allele of rs9939609 in the FTO gene predisposes to increased body mass index (BMI and obesity. Recently we showed an inverse association between the obesity related A allele of rs9939609 and alcohol dependence which was replicated by others. Since this finding raises a possibility that FTO may be associated with other psychiatric phenotypes, we aimed to examine association of rs9939609 with completed suicide. We genotyped rs9939609 in 912 suicide victims and 733 controls using TaqMan approach. We observed an inverse association between suicide and the rs9939609 A allele (OR = 0.80, P = 0.002, Pcor = 0.006 with genotype distribution suggesting a co-dominant effect. Given the link between alcoholism and suicide under influence of alcohol reported in Polish population, confounding by alcohol addiction was unlikely due to apparently similar effect size among cases who were under influence of ethanol at the time of death (OR = 0.76, P = 0.003, N = 361 and those who were not (OR = 0.80, P = 0.007, N = 469. The search for genotype-phenotype correlations did not show significant results. In conclusion, our study proves that there is an inverse association between rs9939609 polymorphism in FTO gene and completed suicide which is independent from association between FTO and alcohol addiction.

  7. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections.

    Science.gov (United States)

    Kuang, Shao-Qing; Medina-Martinez, Olga; Guo, Dong-Chuan; Gong, Limin; Regalado, Ellen S; Reynolds, Corey L; Boileau, Catherine; Jondeau, Guillaume; Prakash, Siddharth K; Kwartler, Callie S; Zhu, Lawrence Yang; Peters, Andrew M; Duan, Xue-Yan; Bamshad, Michael J; Shendure, Jay; Nickerson, Debbie A; Santos-Cortez, Regie L; Dong, Xiurong; Leal, Suzanne M; Majesky, Mark W; Swindell, Eric C; Jamrich, Milan; Milewicz, Dianna M

    2016-03-01

    The ascending thoracic aorta is designed to withstand biomechanical forces from pulsatile blood. Thoracic aortic aneurysms and acute aortic dissections (TAADs) occur as a result of genetically triggered defects in aortic structure and a dysfunctional response to these forces. Here, we describe mutations in the forkhead transcription factor FOXE3 that predispose mutation-bearing individuals to TAAD. We performed exome sequencing of a large family with multiple members with TAADs and identified a rare variant in FOXE3 with an altered amino acid in the DNA-binding domain (p.Asp153His) that segregated with disease in this family. Additional pathogenic FOXE3 variants were identified in unrelated TAAD families. In mice, Foxe3 deficiency reduced smooth muscle cell (SMC) density and impaired SMC differentiation in the ascending aorta. Foxe3 expression was induced in aortic SMCs after transverse aortic constriction, and Foxe3 deficiency increased SMC apoptosis and ascending aortic rupture with increased aortic pressure. These phenotypes were rescued by inhibiting p53 activity, either by administration of a p53 inhibitor (pifithrin-α), or by crossing Foxe3-/- mice with p53-/- mice. Our data demonstrate that FOXE3 mutations lead to a reduced number of aortic SMCs during development and increased SMC apoptosis in the ascending aorta in response to increased biomechanical forces, thus defining an additional molecular pathway that leads to familial thoracic aortic disease.

  8. Factors predisposing to severe acute pancreatitis: evaluation and prevention

    Institute of Scientific and Technical Information of China (English)

    Bei Sun; Ha-Li Li; Yue Gao; Jun Xu; Hong-Chi liang

    2003-01-01

    AIM: To analyze factors predisposing to the infections associated with severe acute pancreatitis (SAP) and to work out ways for its prevention.METHODS: Total 208 cases of SAP treated in this hospital from Jan. 1980 to Dec. 2001 were retrospectively analyzed.RESULTS: Statistical difference in the incidence of the aforementioned infections was found between the following pairs: between the groups of bloody or non-bloody ascites,paralytic ileus lasting shorter or longer than 5 days, Ranson scores lower or higher than 5, hematocrit lower or higher than 45 %, CT Balthazar scores lower or higher than 7 and between 1980.1-1992.6 or 1992.7-2001.12 admissions (χ2>3.84, P<0.05), while no statistical difference was established between the groups of biliogenic and nonbiliogenic pancreatitis, serum amylase <200 U/L and ≥200U/L, serum calcium <2 mmol/L and ≥ 2 mmol/L or groups of total parenteral nutrition shorter or longer than 7 days (χ2<3.84, P>0.05).CONCLUSION: Occurrence of infection in patients with SAP is closely related with bloody ascites, paralytic ileus ≥5 days, Ranson scores ≥5, hematocrit ≥45 % and CT Balthazar Scores ≥7, but not with pathogens, serum calcium and total parenteral nutrition (TPN). Comprehensive prevention of pancreatic infection and practice of individualized therapy contribute to reducing the incidence of infection.

  9. Sleep deprivation predisposes Gujarati Indian adolescents to obesity

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    Shaikh Wasim

    2009-01-01

    Full Text Available Background and Aim: Recent studies on various populations indicate that lack of sleep is one of the potential risk factors predisposing the youth to obesity. Since there is a significant rise in obesity among Indian youth and because research indicating the role of sleep in development of obesity among Indian population is scant, the current study was undertaken to assess the effect of sleep duration on adiposity among Gujarati Indian adolescents. Materials and Methods: A randomized cross-sectional study was done on 489 voluntarily participating Indian adolescents in the age group of 16-19 years. Participants were grouped into two categories 1. Adequate Sleep Duration at Night (more than seven hours, ASDN and 2 Inadequate Sleep Duration at Night (less than seven hours, IASDN as reported by the participants. The participants were later assessed for adiposity in terms of BMI, BF % , FM, FMI and waist circumference, meal frequency per day and physical activity status. Results: In both boys as well as girls, the BMI, BF%, FM and FMI were significantly lower in the ASDN group than the IASDN group. However, there was an insignificant difference in the meal frequency and physical activity status between the ASDN and IASDN group. Conclusion : Inadequate sleep duration increases adiposity among Gujarati Indian adolescents but further studies are required to find out the mechanisms through which sleep affects adiposity in this population.

  10. An Evaluation of Factors Predisposing Building Elements to Variation in Nigeria

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    Babatunde, S.O.

    2013-01-01

    Full Text Available The construction industry has been consistently criticized for poor performance in attaining clients’ requirements. The study, thus, assessed the factors predisposing building elements to variation with a view to providing cost-design information that enhance construction project delivery, that is, on-time completion of project within budget. The building elements considered in this study include substructure, frame, upper floors, and roof. Data were collected using well-structured questionnaires administered on professionals in consulting firms, contracting firms, and client organizations in Lagos metropolis. Data analysis was done using descriptive and inferential statistics. The results of the analysis revealed nine factors through factor analysis that predispose substructure to variation, seven factors predispose frame, six factors predispose upper floors, and seven factors predispose roofs to variation during construction process in Nigeria.

  11. Effect of Selenium, molybdenum and boron on ameloblast morphology and the expression of PCMA,C-MYC in fluorosis rat%硒、钼、硼对氟中毒大鼠成釉细胞形态及PCNA、C-myc表达变化的影响

    Institute of Scientific and Technical Information of China (English)

    汤晔; 陈黎明

    2011-01-01

    目的 观察硒、钼、硼对氟中毒大鼠成釉细胞形态及增殖细胞核抗原(PCNA),C-myc 基因表达变化的影,气方法大鼠分组均喂以含F-45 mg/L的蒸馏水及含不同浓度硒、钼、硼的饲料,建立微量元素拮抗氟中毒的大鼠模型.采用HE染色及免疫组化的方法观察氟对成釉细胞的影响,采用图像分析技术时免疫组化结果进行量化分析.结果 实验组成釉细胞形态较正常,PCNA表达增强,C-myc表达减弱.结论 硒、钼、硼减轻氟毒性的机制可能与通过拮抗氟引起的C-myc表达增强、PCNA表达减弱等作用有关.

  12. Somatic overgrowth predisposes to seizures in autism spectrum disorders.

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    Giulia Valvo

    Full Text Available BACKGROUND: Comorbidity of Autism Spectrum Disorders with seizures or abnormal EEG (Autism-Epilepsy Phenotype suggests shared pathomechanisms, and might be a starting point to identify distinct populations within the clinical complexity of the autistic spectrum. In this study, we tried to assess whether distinct subgroups, having distinctive clinical hallmarks, emerge from this comorbid condition. METHODS: Two-hundred and six individuals with idiopathic Autism Spectrum Disorders were subgrouped into three experimental classes depending on the presence of seizures and EEG abnormalities. Neurobehavioral, electroclinical and auxological parameters were investigated to identify differences among groups and features which increase the risk of seizures. Our statistical analyses used ANOVA, post-hoc multiple comparisons, and the Chi-squared test to analyze continuous and categorical variables. A correspondence analysis was also used to decompose significant Chi-squared and reduce variables dimensions. RESULTS: The high percentage of children with seizures (28.2% of our whole cohort and EEG abnormalities (64.1% confirmed that the prevalence of epilepsy in Autism Spectrum Disorders exceeds that of the general population. Seizures were associated with severe intellectual disability, and not with autism severity. Interestingly, tall stature (without macrocephaly was significantly associated with EEG abnormalities or later onset seizures. However, isolated macrocephaly was equally distributed among groups or associated with early onset seizures when accompanied by tall stature. CONCLUSIONS: Tall stature seems to be a phenotypic "biomarker" of susceptibility to EEG abnormalities or late epilepsy in Autism Spectrum Disorders and, when concurring with macrocephaly, predisposes to early onset seizures. Growth pattern might act as an endophenotypic marker in Autism-Epilepsy comorbidity, delineating distinct pathophysiological subtypes and addressing personalized

  13. Mineral deficiency predisposes occurrence of retention of placenta in crossbred

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    S. K. Sheetal

    2014-12-01

    Full Text Available Aim: The present study was carried out to investigate the relationship between blood serum concentrations of macro and micro minerals and development of retention of placenta (ROP in crossbred cattle. Materials and Methods: The present study was carried out at Instructional Livestock Farm, Bihar Veterinary College and local Khatals in and around Patna. A total of 20 crossbred cattle (n=10 with normal expulsion of the placenta as control and n=10 with ROP were selected in the present study. Blood samples were collected from these animals and serum was separated and stored in the deep freezer at −20°C till further analysis. The estimation of serum macro-minerals (Ca, P, Ca/P ratio was done by Span diagnostic Kits (Surat, India and trace minerals or micro-minerals (Zn, Cu, and Fe were analyzed by atomic absorption spectrophotometer (Perkin Elmer AAS 220. Mean values were compared between both the groups at 0 h (at parturition and 12 h after parturition. Results: The mean values of serum calcium and zinc were found significantly lower in cattle having ROP than control at both 0 h and 12 h after parturition. The mean values of serum Ca and P ratio obtained at 0 hour were significantly lower in ROP groups as compared to control groups and non-significant at 12 h. The mean values of serum inorganic phosphorus, copper and iron was found non-significantly lower in ROP cases as compared to control. Conclusions: Macro and micro mineral deficiency such as calcium, iron, zinc and copper in blood serum may be predisposing factor for the occurrence of retention of placenta in crossbred cattle.

  14. Influence of DNA methyltransferase 3b on the expression of STAT1 and C-myc and the methylation of promoters in human hepatocellular carcinolna cell line%DNA甲基转移酶3b对肝癌细胞株中STAT1及其下游基因c-myc的表达和启动子甲基化的影响

    Institute of Scientific and Technical Information of China (English)

    司亚卿; 王佳辰; 王家祥

    2009-01-01

    Objective To invetigate the influence of DNMT3b of SMMC7721 on the expression of STAT1 and c-myc and the methylation of promoters,and further study the functions of DNMT3b.Methods DNMT3b was silenced by siRNA in human hepatocellular carcinoma cell line SMMC-7721.Westem blotting was performed to evaluate the expression of sTAT1 and c-myc.Methylation specific PCR(MSP)was performed to investigate whether the promoters of STAT1 and c-myc were methylated.Results Western blot analysis showed that the expression of DNMT3b and c-myc in DNMT3bsiRNA transfection group was decreased significantly as compared with the control group,and the expression of STATI increased significanfly.There was no significant difierence in the state of methylation between the transfection and control groups.Conclusion DNMT3b may regulate the expression STAT1 and c-myc in SMMC7721 cells,but not change the state of methylation,suggesting DNMT3b may play roles as transcription factors.%目的 探讨DNA甲基转移酶3b(DNMT3b)在人肝癌细胞株(SMMC7721)中对STAT1和c-myc基因表达及其启动子甲基化水平的影响,并进一步探讨DNMT3b的作用.方法 用DNMT3bsiRNA抑制DNMT3b在SMMC7721细胞系中的表达,用Western blot技术检测其转染前后DNMT3b及STAT1和c-myc基因的表达.应用甲基化特异性PCR(MSP)技术分别检测两组细胞中STAT1和c-myc基因启动子区的甲基化状况.结果 转染DNMT3bsiRNA的实验组DNMT3b表达水平明显低于对照组,STAT1基因的表达高于对照组;c-myc基因的表达低于对照组.两组中STAT1和c-myc基因启动子区甲基化状态无差异,均未发生甲基化.结论 DNM33b可以调节STAT1和c-myc基因的表达,而不改变基因的甲基化状态,可能发挥了转录调控因子的作用.

  15. Urological complications after radical hysterectomy: Incidence rates and predisposing factors

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    Likić-Lađević Ivana

    2007-01-01

    Full Text Available Bacground/Aim. Radical hysterectomy is a surgical approach for stage Ib and IIa of cervical cancer. The incidence of intraoperative injuries of the bladder during radical hysterectomy ranges from 0.4-3.7%. The ureter can be crushed, caught in sutures, transsected, obstructed by angulation, or ischemic by the stippling or periureteric fascia. Vesicovaginal and ureterovaginal fistuls are reported to develop in 0.9-2% of patients after radical abdominal hysterectomy. Fistulas usually become manifested or visible at speculum examination within 14 days following the surgery. The aim of this study was to establish the incidence and predisposing factor of urological complications after radical hysterectomy. Methods. The study included a total of 536 patients with invasive stage Ib to IIb cancer of the cervix uteri who had underwent radical hysterectomy. The special elements considered were: the patient’s age; the International Federation of Ginecology and Obstetrics (FIGO stage after pathohistology; duration of operation; the result of preoperative laboratory tests for diabetes, anemia, hypoproteinemia, or disorders of liver or kidney function; ASA status; postoperative surgical infection. Results. The average age of the patients with complications was 48.68 years. All patients with intraoperative ureteric and bladder injuries had statisticaly significant higher stage of disease and operation lasted more than in others without injury. We noticed 1.3% ureteral injuries and 1.49% bladder injuries, more than 50% of the patients with a previously mentioned injuries were operated on more than 3 hours. We found 2.61% vesicovaginal and 2.43% ureterovaginal fistuls. A total of 50% of the patients with bladder injury and vesicovaginal fistuls and 70% of the patients with ureterovaginal fistuls had diabetes mellitus. Postoperative infection of surgical site is a very important factor for the development of fistule. Half of the patients with vesicovaginal

  16. 32 CFR 644.389 - Army military-modified predisposal procedures where E.O. 11954 surveys have been made.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Army military-modified predisposal procedures... (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Predisposal Action § 644.389 Army military—modified predisposal procedures where E.O. 11954 surveys have been made. (a)...

  17. Deciphering c-MYC-regulated genes in two distinct tissues

    Directory of Open Access Journals (Sweden)

    Hunter Ewan

    2011-09-01

    Full Text Available Abstract Background The transcription factor MYC is a critical regulator of diverse cellular processes, including both replication and apoptosis. Differences in MYC-regulated gene expression responsible for such opposing outcomes in vivo remain obscure. To address this we have examined time-dependent changes in global gene expression in two transgenic mouse models in which MYC activation, in either skin suprabasal keratinocytes or pancreatic islet β-cells, promotes tissue expansion or involution, respectively. Results Consistent with observed phenotypes, expression of cell cycle genes is increased in both models (albeit enriched in β-cells, as are those involved in cell growth and metabolism, while expression of genes involved in cell differentiation is down-regulated. However, in β-cells, which unlike suprabasal keratinocytes undergo prominent apoptosis from 24 hours, there is up-regulation of genes associated with DNA-damage response and intrinsic apoptotic pathways, including Atr, Arf, Bax and Cycs. In striking contrast, this is not the case for suprabasal keratinocytes, where pro-apoptotic genes such as Noxa are down-regulated and key anti-apoptotic pathways (such as Igf1-Akt and those promoting angiogenesis are up-regulated. Moreover, dramatic up-regulation of steroid hormone-regulated Kallikrein serine protease family members in suprabasal keratinocytes alone could further enhance local Igf1 actions, such as through proteolysis of Igf1 binding proteins. Conclusions Activation of MYC causes cell growth, loss of differentiation and cell cycle entry in both β-cells and suprabasal keratinocytes in vivo. Apoptosis, which is confined to β-cells, may involve a combination of a DNA-damage response and downstream activation of pro-apoptotic signalling pathways, including Cdc2a and p19Arf/p53, and downstream targets. Conversely, avoidance of apoptosis in suprabasal keratinocytes may result primarily from the activation of key anti-apoptotic signalling pathways, particularly Igf1-Akt, and induction of an angiogenic response, though intrinsic resistance to induction of p19Arf by MYC in suprabasal keratinocytes may contribute.

  18. Evaluation of Molecular Inhibitors of the c-Myc Oncoprotein

    Science.gov (United States)

    2007-02-01

    G1 growth arrest. Improved Myc-Max Inhibitors2 Mol Cancer Ther 2007;6(9). September 2007 Growth ofMammalian Cells HL60 human promyelocytic leukemia ...Supplementary Fig. S1.7 Each compound was initially tested for its ability to inhibit the growth of the HL60 human promyelocytic leukemia cell line, which...apoptosis, and myeloid differentiation of human acute myeloid leukemia . Exp Hematol 2006;34: 1480–9. 19. Zhang H, Fan S, Prochownik EV. Distinct

  19. A Conditioned Medium of Umbilical Cord Mesenchymal Stem Cells Overexpressing Wnt7a Promotes Wound Repair and Regeneration of Hair Follicles in Mice

    Science.gov (United States)

    Dong, Liang; Hao, Haojie; Liu, Jiejie; Ti, Dongdong; Tong, Chuan; Hou, Qian; Li, Meirong; Zheng, Jingxi; Liu, Gang

    2017-01-01

    Mesenchymal stem cells (MSCs) can affect the microenvironment of a wound and thereby accelerate wound healing. Wnt proteins act as key mediators of skin development and participate in the formation of skin appendages such as hair. The mechanisms of action of MSCs and Wnt proteins on skin wounds are largely unknown. Here, we prepared a Wnt7a-containing conditioned medium (Wnt-CM) from the supernatant of cultured human umbilical cord-MSCs (UC-MSCs) overexpressing Wnt7a in order to examine the effects of this CM on cutaneous healing. Our results revealed that Wnt-CM can accelerate wound closure and induce regeneration of hair follicles. Meanwhile, Wnt-CM enhanced expression of extracellular matrix (ECM) components and cell migration of fibroblasts but inhibited the migratory ability and expression of K6 and K16 in keratinocytes by enhancing expression of c-Myc. However, we found that the CM of fibroblasts treated with Wnt-CM (HFWnt-CM-CM) can also promote wound repair and keratinocyte migration; but there was no increase in the number of hair follicles of regeneration. These data indicate that Wnt7a and UC-MSCs have synergistic effects: they can accelerate wound repair and induce hair regeneration via cellular communication in the wound microenvironment. Thus, this study opens up new avenues of research on the mechanisms underlying wound repair.

  20. A Conditioned Medium of Umbilical Cord Mesenchymal Stem Cells Overexpressing Wnt7a Promotes Wound Repair and Regeneration of Hair Follicles in Mice

    Directory of Open Access Journals (Sweden)

    Liang Dong

    2017-01-01

    Full Text Available Mesenchymal stem cells (MSCs can affect the microenvironment of a wound and thereby accelerate wound healing. Wnt proteins act as key mediators of skin development and participate in the formation of skin appendages such as hair. The mechanisms of action of MSCs and Wnt proteins on skin wounds are largely unknown. Here, we prepared a Wnt7a-containing conditioned medium (Wnt-CM from the supernatant of cultured human umbilical cord-MSCs (UC-MSCs overexpressing Wnt7a in order to examine the effects of this CM on cutaneous healing. Our results revealed that Wnt-CM can accelerate wound closure and induce regeneration of hair follicles. Meanwhile, Wnt-CM enhanced expression of extracellular matrix (ECM components and cell migration of fibroblasts but inhibited the migratory ability and expression of K6 and K16 in keratinocytes by enhancing expression of c-Myc. However, we found that the CM of fibroblasts treated with Wnt-CM (HFWnt-CM-CM can also promote wound repair and keratinocyte migration; but there was no increase in the number of hair follicles of regeneration. These data indicate that Wnt7a and UC-MSCs have synergistic effects: they can accelerate wound repair and induce hair regeneration via cellular communication in the wound microenvironment. Thus, this study opens up new avenues of research on the mechanisms underlying wound repair.

  1. Consequences of over-expression of rat Scavenger Receptor, SR-BI, in an adrenal cell model

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    Azhar Salman

    2006-12-01

    Full Text Available Abstract Background The plasma membrane scavenger receptor, SR-BI, mediates the 'selective uptake' process by which cholesteryl esters (CE from exogenously supplied HDL are taken up by target cells. Recent work suggests that dimer and higher order oligomeric forms of the SR-BI protein are important to this process. SR-BI has been shown to be particularly associated with microvilli and microvillar channels found at the cell surface of steroidogenic cells, and a study with the hormone stimulated adrenal gland has shown impressive changes in the size and complexity of the microvillar compartment as the mass of CE uptake (and accompanying steroidogenesis fluctuates. In the present study, we examine a cell line in which we overexpress the SR-BI protein to determine if morphological, biochemical and functional events associated with SR-BI in a controlled cell system are similar to those observed in the intact mammalian adrenal which is responsive to systemic factors. Methods Y1-BS1 mouse adrenocortical cells were transiently transfected using rat SR-BI-pcDNA6-V5-His, rat SR-BI-pcDNA6-cMyc-His or control pcDNA6-V5-His vector construct using a CaPO4 precipitation technique. Twenty four hours after transfection, cells were treated with, or without, Bt2cAMP, and SR-BI expression, CE uptake, and steroidogenesis was measured. SR-BI dimerization and cell surface architectural changes were assessed using immunoelectron microscopic techniques. Results Overexpression of the scavenger receptor protein, SR-BI, in Y1-BS1 cells results in major alterations in cell surface architecture designed to increase uptake of HDL supplied-CEs. Changes include 1 the formation of crater-like erosions of the surface with multiple double membraned channel structures lining the craters, and 2 dimerized formations of SR-BI lining the newly formed craters and associated double membraned channels. Conclusion These data show that overexpression of the scavenger receptor protein, SR

  2. Overexpression of X-linked genes in T cells from women with lupus.

    Science.gov (United States)

    Hewagama, Anura; Gorelik, Gabriela; Patel, Dipak; Liyanarachchi, Punsisi; McCune, W Joseph; Somers, Emily; Gonzalez-Rivera, Tania; Strickland, Faith; Richardson, Bruce

    2013-03-01

    Women develop lupus more frequently than men and the reason remains incompletely understood. Evidence that men with Klinefelter's Syndrome (XXY) develop lupus at approximately the same rate as women suggests that a second X chromosome contributes. However, since the second X is normally inactivated, how it predisposes to lupus is unclear. DNA methylation contributes to the silencing of one X chromosome in women, and CD4+ T cell DNA demethylation contributes to the development of lupus-like autoimmunity. This suggests that demethylation of genes on the inactive X may predispose women to lupus, and this hypothesis is supported by a report that CD40LG, an immune gene encoded on the X chromosome, demethylates and is overexpressed in T cells from women but not men with lupus. Overexpression of other immune genes on the inactive X may also predispose women to this disease. We therefore compared mRNA and miRNA expression profiles in experimentally demethylated T cells from women and men as well as in T cells from women and men with lupus. T cells from healthy men and women were treated with the DNA methyltransferase inhibitor 5-azacytidine, then X-linked mRNAs were surveyed with oligonucleotide arrays, and X-linked miRNA's surveyed with PCR arrays. CD40LG, CXCR3, OGT, miR-98, let-7f-2*, miR 188-3p, miR-421 and miR-503 were among the genes overexpressed in women relative to men. MiRNA target prediction analyses identified CBL, which downregulates T cell receptor signaling and is decreased in lupus T cells, as a gene targeted by miR-188-3p and miR-98. Transfection with miR-98 and miR-188-3p suppressed CBL expression. The same mRNA and miRNA transcripts were also demethylated and overexpressed in CD4+ T cells from women relative to men with active lupus. Together these results further support a role for X chromosome demethylation in the female predisposition to lupus.

  3. Identifying Some Factors That Might Predispose Drug Abuse among Learners in a South African Township School

    Science.gov (United States)

    Grobler, R.; Khatite, M.

    2012-01-01

    This study inquires into some of the factors that might predispose the use and abuse of drugs among secondary school learners in a township school. The objective of this research is to identify these factors and to offer a few suggestions on how the abuse may be prevented. A quantitative research strategy is used and a document analysis technique…

  4. Diet- and colonization-dependent intestinal dysfunction predisposes to necrotizing enterocolitis in preterm pigs

    DEFF Research Database (Denmark)

    Sangild, Per T.; Siggers, Richard H.; Schmidt, Mette;

    2006-01-01

    Background & Aims: Preterm birth and formula feeding are key risk factors associated with necrotizing enterocolitis (NEC) in infants, but little is known about intestinal conditions that predispose to disease. Thus, structural, functional, and microbiologic indices were used to investigate the et...

  5. The Influence of Predisposing, Enabling and Need Factors on Condom Use in Ivory Coast

    Science.gov (United States)

    Ngamini Ngui, Andre

    2010-01-01

    The main objective of this study was to identify key determinants of condom use in Ivory Coast. Data stem from Ivory Coast Demographic Health Survey (DHS) conducted by ORC Macro in 2005 among a representative sample of 9,686 persons aged 15 - 49. Following the behavioral model, we use logistic regression to assess the effect of predisposing,…

  6. Chromosome 21 Scan in Down Syndrome Reveals DSCAM as a Predisposing Locus in Hirschsprung Disease

    NARCIS (Netherlands)

    A-S. Jannot (Anne-Sophie); A. Pelet (Anna); A. Henrion-Caude (Alexandra); A. Chaoui (Asma); M. Masse-Morel (Marine); S. Arnold (Stacey); D. Sanlaville (Damien); I. Ceccherini (Isabella); S. Borrego (Salud); R.M.W. Hofstra (Robert); A. Munnich (Arnold); N. Bondurand (Nadège); A. Chakravarti (Aravinda); F. Clerget-Darpoux (Françoise); J. Amiel (Jeanne); S. Lyonnet (Stanislas)

    2013-01-01

    textabstractHirschsprung disease (HSCR) genetics is a paradigm for the study and understanding of multigenic disorders. Association between Down syndrome and HSCR suggests that genetic factors that predispose to HSCR map to chromosome 21. To identify these additional factors, we performed a dose-dep

  7. Genetic factors predisposing to homosexuality may increase mating success in heterosexuals

    NARCIS (Netherlands)

    Zietsch, B.P.; Morley, K.I.; Shekar, S.N.; Verweij, K.J.H.; Keller, M.C.; MacGregor, S.; Wright, M.J.; Bailey, J.M.; Martin, N.G.

    2008-01-01

    There is considerable evidence that human sexual orientation is genetically influenced, so it is not known how homosexuality, which tends to lower reproductive success, is maintained in the population at a relatively high frequency. One hypothesis proposes that while genes predisposing to homosexual

  8. Candidate colorectal cancer predisposing gene variants in Chinese early-onset and familial cases

    NARCIS (Netherlands)

    Zhang, J.X.; Fu, L.; Voer, R.M. de; Hahn, M.M.; Jin, P.; Lv, C.X.; Verwiel, E.T.; Ligtenberg, M.J.L.; Hoogerbrugge, N.; Kuiper, R.P.; Sheng, J.Q.; Geurts van Kessel, A.H.M.

    2015-01-01

    AIM: To investigate whether whole-exome sequencing may serve as an efficient method to identify known or novel colorectal cancer (CRC) predisposing genes in early-onset or familial CRC cases. METHODS: We performed whole-exome sequencing in 23 Chinese patients from 21 families with non-polyposis CRC

  9. NUCKS overexpression in breast cancer

    Directory of Open Access Journals (Sweden)

    Kittas Christos

    2009-08-01

    Full Text Available Abstract Background NUCKS (Nuclear, Casein Kinase and Cyclin-dependent Kinase Substrate is a nuclear, DNA-binding and highly phosphorylated protein. A number of reports show that NUCKS is highly expressed on the level of mRNA in several human cancers, including breast cancer. In this work, NUCKS expression on both RNA and protein levels was studied in breast tissue biopsies consisted of invasive carcinomas, intraductal proliferative lesions, benign epithelial proliferations and fibroadenomas, as well as in primary cultures derived from the above biopsies. Specifically, in order to evaluate the level of NUCKS protein in correlation with the histopathological features of breast disease, immunohistochemistry was employed on paraffin sections of breast biopsies of the above types. In addition, NUCKS expression was studied by means of Reverse Transcription PCR (RT-PCR, real-time PCR (qRT-PCR and Western immunoblot analyses in the primary cell cultures developed from the same biopsies. Results The immunohistochemical Results showed intense NUCKS staining mostly in grade I and II breast carcinomas compared to normal tissues. Furthermore, NUCKS was moderate expressed in benign epithelial proliferations, such as adenosis and sclerosing adenosis, and highly expressed in intraductal lesions, specifically in ductal carcinomas in situ (DCIS. It is worth noting that all the fibroadenoma tissues examined were negative for NUCKS staining. RT-PCR and qRT-PCR showed an increase of NUCKS expression in cells derived from primary cultures of proliferative lesions and cancerous tissues compared to the ones derived from normal breast tissues and fibroadenomas. This increase was also confirmed by Western immunoblot analysis. Although NUCKS is a cell cycle related protein, its expression does not correlate with Ki67 expression, neither in tissue sections nor in primary cell cultures. Conclusion The results show overexpression of the NUCKS protein in a number of non

  10. Predisposing factors for early retirement in patients with schizophrenia in Germany.

    Science.gov (United States)

    Schnabel, Reinhard; Friedel, Heiko; Erfurth, Andreas; Angermayer, Matthias; Clouth, Johannes; Eichmann, Florian

    2008-08-01

    Although early retirement causes major changes in the life of schizophrenic patients and is among the major cost factors to be covered by payers, the causes leading to early retirement of schizophrenic patients have not been investigated in detail. Therefore, the objective of this retrospective non-interventional case-control study was to generate hypotheses on predisposing factors for early retirement in schizophrenia. Logistic regression was used to explore potential predisposing parameters with regard to their effect on the outcome early retirement. As the study results indicate, schizophrenia severity, assistance or care in the patient's everyday life, age and antipsychotic treatment with typical antipsychotics are linked to the occurrence of early retirement. Further research should be planned to confirm or refute the hypotheses determined in this retrospective analysis and to determine whether atypical antipsychotics could help to avoid early retirement and to improve the situation of schizophrenic patients.

  11. Extremely high frequency of autoimmune-predisposing alleles in medieval specimens

    Institute of Scientific and Technical Information of China (English)

    WITAS H.W.; J(E)DRYCHOWSKA-DA(N)SKA K.; ZAWICKI P.

    2007-01-01

    The precise etiology and reasons for the increase in incidence of autoimmune disorders still remain unclear, and although both genetic and environmental factors have been proven to shape individual predisposition, it is not known which of the factors, if not both, is responsible for the boom observed during the last decades. In order to establish whether a higher frequency of autoimmune-predisposing alleles may explain this increase we took advantage of ancient DNA methodology to establish the genetic predisposition, conferred by cytotoxic T lymphocyte associated antigen-4 (CTLA4) +49A/G and human leukocyte antigens (HLA)DQB157, in population inhabiting Poland in the Middle Ages. After successful typing of 42 individuals from a 12th~14th's century archeological burial site, we found that frequencies of the predisposing alleles in the medieval population were higher than they are at present, suggesting thus that the recently observed incidence increase results most probably from factors of other than genetic nature.

  12. Predisposing Factors of Complicated Deep Neck Infection: An Analysis of 158 Cases

    OpenAIRE

    Lee, Joon-Kyoo; Kim, Hee-Dae; Lim, Sang-Chul

    2007-01-01

    Both the introduction of antibiotics and improvements in oral hygiene have made deep neck infections occur less frequently today than in the past. Nevertheless, the complications from these infections are often life-threatening. The purpose of this article was to review the clinical findings of deep neck infections and identify the predisposing factors of these complications. The present study reviewed 158 cases of deep neck infections between the years of 1995 to 2004, 23 of which had life-t...

  13. Synergistic effect of multiple predisposing risk factors on the development of bezoars

    Institute of Scientific and Technical Information of China (English)

    Metin Kement; Nuraydin Ozlem; Elif Colak; Sadik Kesmer; Cem Gezen; Selahattin Vural

    2012-01-01

    AIM:To describe the clinical characteristics of patients with gastric or intestinal bezoars recently treated in our hospital.METHODS:In this study,a retrospective chart review of consecutive patients with gastrointestinal bezoars,who were treated at the Samsun Education and Research Hospital between January 2006 and March 2011,was conducted.Data on demographic characteristics,clinical presentation,history of risk factors,diagnostic procedures,localization of bezoars,treatment interventions,and postoperative morbidity and mortality rates were collected and evaluated.RESULTS:Forty-two patients [26 (61.9%) males and 16 (31.1%) females] with a mean ± SD (range) age of 55.8 ± 10.5 (37-74) years were enrolled in this study,.Thirty-six patients (85.7%) had one or more predisposing risk factors for gastrointestinal bezoars.The most common predisposing risk factor was a history of previous gastric surgery which was identified in 18 patients (42.8%).Twenty three patients (54.8%) had multiple predisposing risk factors.Phytobezoars were identified in all patients except one who had a trichobezoar in the stomach.Non-operative endoscopic fragmentation was performed either initially or after unsuccessful medical treatment in 14 patients with gastric bezoars and was completely successful in 10 patients (71.5%).Surgery was the most frequent treatment method in our study,which was required in 28 patients (66.7%).Intestinal obstruction secondary to bezoars was the most common complication (n =18,42.8%) in our study.CONCLUSION:The presence of multiple predisposing factors may create a synergistic effect in the development of bezoars.

  14. Double-strand break damage and associated DNA repair genes predispose smokers to gene methylation

    OpenAIRE

    Leng, Shuguang; Stidley, Christine A.; Willink, Randy; Bernauer, Amanda; Do, Kieu; Picchi, Maria A.; Sheng, Xin; Frasco, Melissa, A.; Berg, David Van Den; Gilliland, Frank D.; Zima, Christopher; Crowell, Richard E.; Belinsky, Steven A.

    2008-01-01

    Gene promoter hypermethylation in sputum is a promising biomarker for predicting lung cancer. Identifying factors that predispose smokers to methylation of multiple gene promoters in the lung could impact strategies for early detection and chemoprevention. This study evaluated the hypothesis that double-strand break repair capacity and sequence variation in genes in this pathway are associated with a high methylation index in a cohort of current and former cancer-free smokers. A 50% reduction...

  15. Predisposing Factors In Patients With Silent Myocardial Infarction Farabi Hospital (2000

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    Mahmoodi M j

    2002-09-01

    Full Text Available Myocardial infarction sequel of coronary artery diseases, can be sometimes asymptomatic, called silent myocardial infarction. Some risk factors predispose the patients to this condition. In this study, we intend to determine the predisposing factors in such patients."nMethods and Materials: We included those patients with electrocardiogram changes, consistent with myocardial infarction, who had not any symptoms of ischemia or a previous history of coronary artery disease, consulted for preoperative work up of eye surgery during the year 2000."nResults: We analyzed 100 patients with the diagnosis of silent myocardial infarction. (59 males and 41 females. Among our patients. 99 percent were above age 50 years of age. Their mean age at the time of study was 69.7 years. 78 percent of patients were illiterate. In 41 of them body mass index was above the normal limits (overweight and obese. Their past medical history revealed that 46 patients had hypertension, 38 patients had hyper-lipidemia. and 26 patients had diabetes mellitus. Also, a positive family history of coronary artery disease was seen in 52 percent of the patients. The rate of cigarette smokers and opium addicts, among our patients, was 33 and 13 percents. respectively. Analysis of electrocardiogram changes, showed that 43 patients had inferior myocardial infarction, 24 had antero-septal. and 17 of them suffered from anterior myocardial infarction."nConclusion: Almost all of our patients with silent myocardial infarction were in old age group. Diabetes mellitus, hypertension, overweight, hyper-lipidemia, and a positive family history of coronary artery disease were the most important predisposing factors, found in such patients, thus taking into account these predisposing factors and control of them would dramatically reduce the prevalence of morbidity and mortality of silent myocardial infarction.

  16. Maternal air pollution exposure induces fetal neuroinflammation and predisposes offspring to obesity in aduthood in a sex-specific manner

    Science.gov (United States)

    Emerging evidence suggests environmental chemical exposures during critical windows of development may contribute to the escalating prevalence of obesity. We tested the hypothesis that prenatal air pollution exposure would predispose the offspring to weight gain in adulthood. Pre...

  17. Mycoplasma ovipneumoniae can predispose bighorn sheep to fatal Mannheimia haemolytica pneumonia.

    Science.gov (United States)

    Dassanayake, Rohana P; Shanthalingam, Sudarvili; Herndon, Caroline N; Subramaniam, Renuka; Lawrence, Paulraj K; Bavananthasivam, Jegarubee; Cassirer, E Frances; Haldorson, Gary J; Foreyt, William J; Rurangirwa, Fred R; Knowles, Donald P; Besser, Thomas E; Srikumaran, Subramaniam

    2010-10-26

    Mycoplasma ovipneumoniae has been isolated from the lungs of pneumonic bighorn sheep (BHS). However experimental reproduction of fatal pneumonia in BHS with M. ovipneumoniae was not successful. Therefore the specific role, if any, of M. ovipneumoniae in BHS pneumonia is unclear. The objective of this study was to determine whether M. ovipneumoniae alone causes fatal pneumonia in BHS, or predisposes them to infection by Mannheimia haemolytica. We chose M. haemolytica for this study because of its isolation from pneumonic BHS, and its consistent ability to cause fatal pneumonia under experimental conditions. Since in vitro culture could attenuate virulence of M. ovipneumoniae, we used ceftiofur-treated lung homogenates from pneumonic BHS lambs or nasopharyngeal washings from M. ovipneumoniae-positive domestic sheep (DS) as the source of M. ovipneumoniae. Two adult BHS were inoculated intranasally with lung homogenates while two others received nasopharyngeal washings from DS. All BHS developed clinical signs of respiratory infection, but only one BHS died. The dead BHS had carried leukotoxin-positive M. haemolytica in the nasopharynx before the onset of this study. It is likely that M. ovipneumoniae colonization predisposed this BHS to fatal infection with the M. haemolytica already present in this animal. The remaining three BHS developed pneumonia and died 1-5 days following intranasal inoculation with M. haemolytica. On necropsy, lungs of all four BHS showed lesions characteristic of bronchopneumonia. M. haemolytica and M. ovipneumoniae were isolated from the lungs. These results suggest that M. ovipneumoniae alone may not cause fatal pneumonia in BHS, but can predispose them to fatal pneumonia due to M. haemolytica infection.

  18. Technical Note: Assessing predictive capacity and conditional independence of landslide predisposing factors for shallow landslide susceptibility models

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    S. Pereira

    2012-04-01

    Full Text Available The aim of this study is to identify the landslide predisposing factors' combination using a bivariate statistical model that best predicts landslide susceptibility. The best model is one that has simultaneously good performance in terms of suitability and predictive power and has been developed using variables that are conditionally independent. The study area is the Santa Marta de Penaguião council (70 km2 located in the Northern Portugal.

    In order to identify the best combination of landslide predisposing factors, all possible combinations using up to seven predisposing factors were performed, which resulted in 120 predictions that were assessed with a landside inventory containing 767 shallow translational slides. The best landslide susceptibility model was selected according to the model degree of fitness and on the basis of a conditional independence criterion. The best model was developed with only three landslide predisposing factors (slope angle, inverse wetness index, and land use and was compared with a model developed using all seven landslide predisposing factors.

    Results showed that it is possible to produce a reliable landslide susceptibility model using fewer landslide predisposing factors, which contributes towards higher conditional independence.

  19. CYP2J2 overexpression protects against arrhythmia susceptibility in cardiac hypertrophy.

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    Christina Westphal

    Full Text Available Maladaptive cardiac hypertrophy predisposes one to arrhythmia and sudden death. Cytochrome P450 (CYP-derived epoxyeicosatrienoic acids (EETs promote anti-inflammatory and antiapoptotic mechanisms, and are involved in the regulation of cardiac Ca(2+-, K(+- and Na(+-channels. To test the hypothesis that enhanced cardiac EET biosynthesis counteracts hypertrophy-induced electrical remodeling, male transgenic mice with cardiomyocyte-specific overexpression of the human epoxygenase CYP2J2 (CYP2J2-TG and wildtype littermates (WT were subjected to chronic pressure overload (transverse aortic constriction, TAC or β-adrenergic stimulation (isoproterenol infusion, ISO. TAC caused progressive mortality that was higher in WT (42% over 8 weeks after TAC, compared to CYP2J2-TG mice (6%. In vivo electrophysiological studies, 4 weeks after TAC, revealed high ventricular tachyarrhythmia inducibility in WT (47% of the stimulation protocols, but not in CYP2J2-TG mice (0%. CYP2J2 overexpression also enhanced ventricular refractoriness and protected against TAC-induced QRS prolongation and delocalization of left ventricular connexin-43. ISO for 14 days induced high vulnerability for atrial fibrillation in WT mice (54% that was reduced in CYP-TG mice (17%. CYP2J2 overexpression also protected against ISO-induced reduction of atrial refractoriness and development of atrial fibrosis. In contrast to these profound effects on electrical remodeling, CYP2J2 overexpression only moderately reduced TAC-induced cardiac hypertrophy and did not affect the hypertrophic response to β-adrenergic stimulation. These results demonstrate that enhanced cardiac EET biosynthesis protects against electrical remodeling, ventricular tachyarrhythmia, and atrial fibrillation susceptibility during maladaptive cardiac hypertrophy.

  20. A new predisposing factor for trigemino-cardiac reflex during subdural empyema drainage: a case report

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    Arasho Belachew

    2010-11-01

    Full Text Available Abstract Introduction The trigemino-cardiac reflex is defined as the sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, apnea, or gastric hypermotility during stimulation of any of the sensory branches of the trigeminal nerve. Clinically, trigemino-cardiac reflex has been reported to occur during neurosurgical skull-base surgery. Apart from the few clinical reports, the physiological function of this brainstem reflex has not yet been fully explored. Little is known regarding any predisposing factors related to the intraoperative occurrence of this reflex. Case presentation We report the case of a 70-year-old Caucasian man who demonstrated a clearly expressed form of trigemino-cardiac reflex with severe bradycardia requiring intervention that was recorded during surgical removal of a large subdural empyema. Conclusion To the best of our knowledge, this is the first report of an intracranial infection leading to perioperative trigemino-cardiac reflex. We therefore add a new predisposing factor for trigemino-cardiac reflex to the existing literature. Possible mechanisms are discussed in the light of the relevant literature.

  1. Trematode infections in pregnant ewes can predispose to mastitis during the subsequent lactation period.

    Science.gov (United States)

    Mavrogianni, V S; Papadopoulos, E; Spanos, S A; Mitsoura, A; Ptochos, S; Gougoulis, D A; Barbagianni, M S; Kyriazakis, I; Fthenakis, G C

    2014-02-01

    Objective was to investigate if trematode infections predispose ewes to mastitis and/or metritis. We used 80 trematode-infected ewes: primigravidae in group P-A and multigravidae in M-A remained untreated, primigravidae in P-B and multigravidae in M-B were drenched with netobimin and multigravidae in M-C were given rafoxanide. We collected faecal samples for parasitological examination, blood samples for β-hydroxybutyrate concentration measurement and uterine content, teat duct material and milk samples for bacteriological examination. We found significant differences in blood β-hydroxybutyrate concentrations between M-A, M-B and M-C during pregnancy (P ⩽ 0.002). We did not observe significant differences between groups regarding development of metritis (P>0.83). We found that for M-A, M-B and M-C ewes, respectively, median time to first case of mastitis was 5.75, 21 and 6.75 days after lambing (P = 0.003) and incidence risk of mastitis was 0.308, 0.069 and 0.222 (P = 0.047). We postulate that trematode infections predispose ewes to mastitis; perhaps, increased β-hydroxybutyrate blood concentrations adversely affect mammary cellular defences. This is the first report associating parasitic infections with mastitis in sheep.

  2. Factors predisposing to wound infection in cardiac surgery. A prospective study of 517 patients.

    Science.gov (United States)

    Wilson, A P; Livesey, S A; Treasure, T; Grüneberg, R N; Sturridge, M F

    1987-01-01

    Postoperative wound infection can greatly prolong hospital stay after cardiac surgery, so the identification of predisposing factors may help in prevention or early institution of treatment. Transfer of organisms from the leg to the sternum during coronary artery surgery has been proposed as a major additional cause of sepsis. The definition of wound infection is not standardised and therefore makes comparison between centres difficult. In a prospective study of 517 patients, a wound scoring method (ASEPSIS) has been used to register all abnormal wounds to maximise the chances of identifying factors predisposing to infection. Abnormal healing was noted in 99 (19%) sternal wounds and 29 (8%) leg wounds. Obesity was the principal risk factor (P less than 0.005). Diabetes, reoperation, length of preoperative hospital stay, age, sex, or previous cardiac surgery had little effect on wound healing. The range of bacteria isolated from chest wounds after coronary artery surgery was similar to that after valvular surgery, but the rate of isolation was significantly greater. With careful attention to technique, leg wound infection rarely presented a clinical problem and did not appear to be a source of bacteria infecting the chest wound.

  3. Study of Personality Disorders Among Fertile and Infertile Women and Some Predisposing Factors

    Directory of Open Access Journals (Sweden)

    Ahmad Ali Noorbala

    2007-06-01

    Full Text Available Objective: This study aimed to determine prevalence and predisposing factors of personality disorders among infertile in comparison to fertile women. Materials and Methods:  By a descriptive- analytic study in Vali-e-asr Reproductive Health Research Center, 300 women entered the research.  Eysenck personality (EPQ and structured researcher questionnaires were applied for all patients. Demographic characteristics and predisposing personality factors were recorded and personality symptoms were scaled. For data analysis, SPSS-11-5 software system, chi-square and T-test were used.  P-value <0.05 was considered significant.Results: Based on EPQ, personality instability was significantly more frequent in infertile women in comparison to fertile women (P<0.001. Housewives are at higher risk of developing personality instability as compared to working women. This finding was also statistically significant (P<0.001. Conclusion: Considering the high prevalence of personality disorders among infertile women, it seems that more serious attention is required from gynecologists, psychiatrists and psychologists for better treatment of these disorders. The use of psychotherapy, especially supportive methods, should be considered as part of the general therapeutic framework of infertility.

  4. Primary Candida guilliermondii Infection of the Knee in a Patient without Predisposing Factors

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    Gun Woo Lee

    2012-01-01

    Full Text Available Isolated primary candidal infection of joint is extremely rare, with only a few reported cases. It occurs as a result of accidental implantations of fungus during traumatic procedures, such as surgery, and is usually reported in patients with predisposing factors such as immunosuppression, malignancy, and drug abuse. If left untreated, irreversible deformity and pain with severe osteoarticular destruction occur. Thus, early diagnosis and treatment are important. This paper presents a case of 72-year-old man with primary C. guilliermondii infection of knee joint without predisposing factors and previous traumatic procedures, who was misdiagnosed with advanced degenerative osteoarthritis. Our case is the second case of primary C. guilliermondii arthritis of knee to be reported in the English-language literature and the first to be successfully treated with total knee arthroplasty following IV amphotericin B and oral fluconazole. Primary candidal infection of joint is generally asymptomatic or involves only mild pain and swelling in the affected knee. Thus, although the majority of knee joint infections are of a pyogenic or tuberculous origin, if a patient complains of mild pain and swelling in the knee and has mild signs of infection, the possibility of fungal infection should be considered.

  5. [Factors predisposing to acute urine retention in patients with prostatic adenoma].

    Science.gov (United States)

    Davidov, M I

    2007-01-01

    The aim of the trial was to study factors predisposing to acute urine retention (AUR) in patients with prostatic adenoma (PA). The trial was made in Perm Center for Urgent Urological Care. This allowed registration and analysis of all cases of AUR in the city with population of 1 million people. For 11 years there were 1504 episodes of AUR in 1130 PA patients. One AUR episode was registered in 888 (78.6%) patients, two to four--in 242. Questioning of the patients, the disease histories analysis provided information on the factors predisposing to AUR. The following factors provoked AUR: alcohol intake (25.9%), water loading (11.5%), medication (atropin, belladonna, efedrin, aminasin, tizercin, phenobarbital, imisin, promedol, lazix, etc.; 11.4%), acute inflammation of the adenomatous nodes (7.4%), cold (6.7%), spicy food (5.5%), flebitis of the hemorrhoidal veins (5.5%), fatigue (5.1%), emotional stress (3.9%), forced urine retention (3.1%), bed rest (2.8%), sexual excesses (2%), surgical interventions (2%), etc. AUR occurred more often in the morning (at 4 to 8 o'clock a.m.), in the holidays and after them (92.5% of these patients took alcohol), on days with acute fluctuations of atmospheric pressure, temperature, air humidity. A complex of meteoprophylaxis of AUR is proposed.

  6. Posterior reversible encephalopathy syndrome: do predisposing risk factors make a difference in MRI appearance?

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Mang, Christina; Mang, Thomas; Prayer, Daniela [Medical University of Vienna, Department of Radiology, Vienna (Austria); Pirker, Agnes [Medical University of Vienna, Department of Neurology, Vienna (Austria); Klein, Katharina [Medical University of Vienna, Department of Obstetrics and Gynecology, Vienna (Austria); Prchla, Christine [SMZ-Ost Danube Hospital, Department of Pediatrics, Vienna (Austria)

    2009-06-15

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological entity, characterized by typical neurological deficits, distinctive magnetic resonance imaging (MRI) features, and a usually benign clinical course. Although frequently seen in association with hypertensive conditions, many other predisposing factors, notably cytotoxic and immunosuppressant drugs have been associated with PRES. The aim of this study was to determine differences in the MR appearance of PRES according to various risk factors. Thirty consecutive patients with clinical and MRI findings consistent with PRES were included. We identified 24 patients with hypertension-related conditions, including 14 patients with preeclampsia-eclampsia, and six patients without hypertension, in whom PRES was associated with exposition to neurotoxic substances. Lesion distribution, extent of disease, and number of affected brain regions were compared between patients with PRES with and without hypertension, and patients with PRES with and without preeclampsia-eclampsia, respectively. No statistically significant differences in distribution of lesions and extent of disease were observed between patients with PRES with or without hypertension, and patients with or without preeclampsia-eclampsia, respectively. The number of affected brain regions was significantly higher in patients with preeclampsia-eclampsia (p = 0.046), and the basal ganglia region was more frequently involved in these patients (p = 0.066). Apart from a significant higher number of involved brain regions and a tendency for basal ganglia involvement in patients with PRES associated with preeclampsia-eclampsia, the MRI appearance of patients with PRES does not seem to be influenced by predisposing risk factors. (orig.)

  7. Study of psychiatric disorders among fertile and infertile women and some predisposing factors

    Directory of Open Access Journals (Sweden)

    Ahmad Ali Noorbala

    2007-03-01

    Full Text Available Objective: This study aimed to determine prevalence and predisposing factors of psychiatric disorders among infertile in comparison to fertile women. Materials and Methods:  By a descriptive- analytic study in Vali-e-asr Reproductive Health Research Center, 300 women entered the research.   Symptom Checklist -90 -Revised (SCL-90-R test and structured researcher questionnaires were applied for all patients. Demographic characteristics and predisposing psychological and personality factors were recorded and psychological symptoms were scaled. For data analysis, SPSS-11-5 software system, chi-square and T-test were used.  P-value <0.05 was considered significant.Results: Results showed that 44% of infertile and 28.7% of fertile women had psychiatric disorders. Using SCL-90-R test, the highest mean scores among infertile women were found for paranoid ideation, depression and interpersonal sensitivity scales and the lowest scores were related to psychoticism and phobic anxiety scales. Interpersonal sensitivity, depression, phobic anxiety, paranoid ideas and psychoticism scales were significantly different between infertile and fertile women (p<0.05. Housewives were at a statistically significant higher risk for psychiatric disorders as compared to working women (p<0.001. Conclusion: The significantly higher prevalence of psychiatric disorders among infertile women mandates a more serious attention from gynecologists, psychiatrists and psychologists regarding to diagnosis and treatment of these disorders.

  8. Reduced life expectancy seen in hereditary diseases which predispose to early-onset tumors

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    Evans DGR

    2013-07-01

    Full Text Available D Gareth R Evans,1 Sarah Louise Ingham21Genetic Medicine, Manchester Academic Health Science Centre, Central Manchester Foundation Trust, St Mary's Hospital, Manchester, UK; 2Centre for Health Informatics, Institute of Population Health, The University of Manchester, Manchester, UKAbstract: There are several hereditary diseases that are a predisposition to early-onset tumors. These include syndromic conditions like neurofibromatosis 1 and 2, von Hippel–Lindau syndrome, Gorlin syndrome, multiple endocrine neoplasia, and familial adenomatous polyposis; and conditions which are usually not possible to diagnose clinically in a single individual, such as Lynch syndrome and BRCA1/2. Understanding of the mortality in hereditary cancer predisposing diseases is important for developing effective disease treatment programs. A number of studies have been undertaken to investigate the genetic predictors, prevalence and incidence, and treatment outcomes of these diseases; however, the majority examine only the most common of these diseases (eg, neurofibromatosis or BRCA, or look into postoperative survival. The mortality of individuals who are diagnosed with one of these hereditary diseases remains an area for investigation. This review is the first to attempt identification of studies investigating life expectancy in hereditary diseases which predispose to early-onset tumors.Keywords: mortality, survival, life expectancy, early-onset, tumors

  9. Primary Otomycosis in the Indian Subcontinent: Predisposing Factors, Microbiology, and Classification

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    Sampath Chandra Prasad

    2014-01-01

    Full Text Available Objective. To define otomycosis and determine the predisposing factors and microbiology in primary otomycosis. Study Design. Prospective study of two years and review of the literature. Setting. Academic Department of Otolaryngology in a coastal city in India. Patients. 150 immunocompetent individuals of whom 100 consecutive patients with a clinical diagnosis of otomycosis are considered as the study group and 50 consecutive patients with no otomycosis are considered as the control group. Results and Observations. Instillation of coconut oil (42%, use of topical antibiotic eardrops (20%, and compulsive cleaning of external ear with hard objects (32% appeared to be the main predisposing factors in otomycosis. Aspergilli were the most common isolates (80% followed by Penicillium (8%, Candida albicans (4%, Rhizopus (1%, and Chrysosporium (1%, the last being reported for the first time in otomycosis. Among aspergilli, A. niger complex (38% was the most common followed by A. fumigatus complex (27% and A. flavus complex (15%. Bacterial isolates associated with fungi in otomycosis were S. aureus, P. aeruginosa, and Proteus spp. In 42% of healthy external ears fungi were isolated. Conclusion. Aspergillus spp. were the most common fungi isolated, followed by Penicillium. Otomycotic ears are often associated with bacterial isolates when compared to normal ears. Fungi are also present in a significant number of healthy external auditory canals and their profiles match those in cases of otomycosis. The use of terms “primary” and “secondary” otomycosis is important to standardize reporting.

  10. Does clamping during liver surgery predispose to thrombosis of the hepatic veins? Analysis of 210 cases

    Institute of Scientific and Technical Information of China (English)

    Nikolaos Arkadopoulos; Vaia Stafyla; Athanasios Marinis; Vassilios Koutoulidis; Kassiani Theodoraki; Theodosios Theodosopoulos; Ioannis Vassiliou; Nikolaos Dafnios; Georgios Fragulidis; Vassilios Smyrniotis

    2009-01-01

    AIM: To test whether clamping during liver surgery predisposes to hepatic vein thrombosis.METHODS: We performed a retrospective analysis of 210 patients who underwent liver resection with simultaneous inflow and outflow occlusion.Intraoperatively, flow in the hepatic veins was assessed by Doppler ultrasonography during the reperfusion phase. Postoperatively, patency of the hepatic veins was assessed by contrast-enhanced CT angiography,when necessary after 3-6 mo follow up.RESULTS: Twelve pat ients (5.7%) developed intraoperative liver remnant swelling. However,intraoperative ultrasonography did not reveal evidence of hepatic vein thrombosis. In three of these patients a kinking of the common trunk of the middle and left hepatic veins hindering outflow was recognized and was managed successfully by suturing the liver remnant to the diaphragm. Twenty three patients (10.9%) who developed signs of mild outflow obstruction postoperatively, had no evidence of thrombi in the hepatic veins or flow disturbances on ultrasonography and contrast-enhanced CT angiography, while hospitalized. Long term assessment of the patency of the hepatic veins over a 3-6 mo follow-up period did not reveal thrombi formation or clinical manifestations of outflow obstruction.CONCLUSION: Extrahepatic dissection and clamping of the hepatic veins does not predispose to clinically important thrombosis.

  11. A BAP1 mutation in a Danish family predisposes to uveal melanoma and other cancers

    DEFF Research Database (Denmark)

    Aoude, Lauren G; Wadt, Karin; Bojesen, Anders;

    2013-01-01

    with predominantly uveal melanoma but also a range of other tumor types including lung, neuroendocrine, stomach, and breast cancer; as well as pigmented skin lesions. Whole-exome sequencing identified a BAP1 splice mutation located at c.581-2A>G, which leads to a premature truncation of BAP1 in an individual......Truncating germline mutations in the tumor suppressor gene BRCA-1 associated protein-1 (BAP1) have been reported in families predisposed to developing a wide range of different cancer types including uveal melanoma and cutaneous melanoma. There has also been an association between amelanotic tumor...... development and germline BAP1 mutation suggesting a possible phenotypic characteristic of BAP1 mutation carriers. Though there have been many types of cancer associated with germline BAP1 mutation, the full spectrum of disease association is yet to be ascertained. Here we describe a Danish family...

  12. Predisposing factors on the surface of the skin in persons with pityriasis versicolor.

    Science.gov (United States)

    Gloor, M; Kümpel, D; Friederich, H C

    1975-12-31

    This is a report on biochemical and physiological examinations carried out on 20 test persons who in the last 2 years had contacted and completely recovered from pityriasis versicolor and on 25 control persons of corresponding age and sex. The tests on the skin surface of the patients with pityriasis versicolor show, when compared with the corresponding control group, the following significant results: 1. Significantly more amino acids could be extracted from the skin of the pityriasis versicolor patients than from the skin of the control persons. 2. A significantly shorter alkali neutralisation time was to be found in the pityriasis versicolor patients than in the control persons. 3. The degree of water spreading on the skin was found to be significantly reduced in the pityriasis versicolor patients when compared with the control persons. It is probable that these results point to important predisposing factors for pityriasis versicolor.

  13. Metastatic Colon Cancer in an 18-Year-Old without Predisposing Factors

    Directory of Open Access Journals (Sweden)

    Divya Mirchandani

    2016-01-01

    Full Text Available While colorectal carcinoma is a common gastrointestinal cancer in adults, it is rare in pediatrics with an incidence of 1 : 1,000,000 and represents a fraction of neoplasms encountered in children. Malignant neoplasms represent a major cause of mortality in the pediatric age group. While presenting with weight loss, iron deficiency, rectal bleeding, abdominal pain, and change in bowel habits, or symptoms similar to acute appendicitis, the working diagnosis may be considered to be anorexia. This case illustrates the importance of considering colon cancer among other disease entities as a cause of unintentional weight loss in adolescents. While this is a rare occurrence in the pediatric population, significant unintentional weight loss with altered bowel habits should prompt a search for underlying malignancy—even in the absence of a positive family history or predisposing cancer syndromes.

  14. Radiographic analysis of factors predisposing toward tendon tears in the knee extensor mechanism

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    Rodrigo Pires e Albuquerque

    2014-08-01

    Full Text Available Objectives:To review radiographs of patients who suffered tendon tears of the knee extensor apparatus and observe alterations that might be factors predisposing toward this type of injury.Methods:We retrospectively analyzed 60 cases of injury to the knee extensor mechanism that were treated surgically at the Miguel Couto Municipal Hospital between March 2004 and March 2011. Four patients were excluded due to poor quality of the examination.Results:Of the 56 patients evaluated, 23 were considered to be normal and 33 presented radiographic alterations. Among these, eight (24.3% presented suprapatellar osteophytes alone; seven (21.2%, infrapatellar calcification; seven (21.2%, suprapatellar calcification; six (18.2%, supra- and infrapatellar osteophytes; and five (15.1%, infrapatellar osteophytes alone.Conclusion:Radiographic alterations were frequently observed in patients with extensor mechanism tears.

  15. Metastatic Colon Cancer in an 18-Year-Old without Predisposing Factors.

    Science.gov (United States)

    Mirchandani, Divya; Kulpa, Jolanta; Khawar, Nayaab; Kochin, Israel; Narula, Pramod; Sundaram, Revathy

    2016-01-01

    While colorectal carcinoma is a common gastrointestinal cancer in adults, it is rare in pediatrics with an incidence of 1 : 1,000,000 and represents a fraction of neoplasms encountered in children. Malignant neoplasms represent a major cause of mortality in the pediatric age group. While presenting with weight loss, iron deficiency, rectal bleeding, abdominal pain, and change in bowel habits, or symptoms similar to acute appendicitis, the working diagnosis may be considered to be anorexia. This case illustrates the importance of considering colon cancer among other disease entities as a cause of unintentional weight loss in adolescents. While this is a rare occurrence in the pediatric population, significant unintentional weight loss with altered bowel habits should prompt a search for underlying malignancy-even in the absence of a positive family history or predisposing cancer syndromes.

  16. Predisposing effects of cigarette advertising on children's intentions to smoke when older.

    Science.gov (United States)

    Aitken, P P; Eadie, D R; Hastings, G B; Haywood, A J

    1991-04-01

    Six hundred and forty Glasgow children, initially aged between 11 and 14 years, were interviewed twice, with approximately one year between interviews. Children whose intentions to smoke when older became more positive between the two interviews tended to be more aware of cigarette advertising at the time of the first interview (compared with children whose intentions to smoke were negative at both interviews). Children whose intentions to smoke became more negative between the interviews tended to be less appreciative of cigarette advertisements at the time of the first interview (compared with children whose intentions to smoke were positive at both interviews). Since both groups differed from their respective contrast groups before their declared intentions changed, these findings support the view that cigarette advertising has predisposing as well as reinforcing effects on children's attitudes and behaviour with respect to smoking.

  17. Predisposing factors to lateral ankle injury in male comrades marathon runners

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    J. Hiemstra

    2009-02-01

    Full Text Available Introduction: More than two million people experience ankle ligament traumaeach year in the United States. Half of these are severe ligament sprains, however verylittle is known about the factors that predispose individuals to these injuries. The purpose of this study, (which was conducted as an undergraduate research project,was to find a correlation between the characteristics of height, weight and limbdominance and lateral ankle ligament injuries. Method: A  retrospective study was conducted on 114 ultra distance runners whoparticipated in the 2006 Comrades Marathon. During race registration, the runners’ height and weight were measuredafter answering a questionnaire regarding their training. Results: 114 runners responded to the questionnaire. From this cohort, 38 (33.3% had sustained previous lateral ankle injuries. Of these 38 injuries, 47.4% of the injuries occurred on the runner’s dominant limb and 36.8% occurred on thenon-dominant side. 15.8% of the runners sustained previous ankle injuries to both ankles. There was a low negative correlation coefficient of 0.24 with regards to weight as a risk factor. This indicated that the power of the correlationwas 5.93%. The study demonstrates that there is no correlation between an increase in weight and an increase in theincidence of ankle injury. The correlation coefficient indicated a low correlation between an increase in height and the incidence of ankle injury. However, the power of the correlation at 18.37% makes inaccurate any attempt to predict the height at which a runner would be at most risk for lateral ankle injury. Conclusion: Height and weight are not risk factors predisposing subjects to lateral ankle injury. In addition, the studyillustrated that there was no effect of limb dominance on the incidence of lateral ankle injury.

  18. Highlights Regarding Host Predisposing Factors to Recurrent Vulvovaginal Candidiasis: Chronic Stress and Reduced Antioxidant Capacity

    Science.gov (United States)

    Akimoto-Gunther, Luciene; Bonfim-Mendonça, Patrícia de Souza; Takahachi, Gisele; Irie, Mary Mayumi T.; Miyamoto, Sônia; Consolaro, Márcia Edilaine Lopes; Svidzinsk, Terezinha I. Estivalet

    2016-01-01

    We studied host factors that could predispose women to develop recurrent vulvovaginal candidiasis (RVVC), including glycemia, insulin resistance, chronic stress, antioxidant capacity, overall immune status, local inflammation and vaginal microbiota. The presence of yeasts in vaginal culture was screened in 277 women, with or without signs and symptoms of VVC and RVVC. The presence of an inflammatory process and microbiota were analyzed through vaginal bacterioscopy and cervical-vaginal cytology, respectively. Fasting-blood samples were collected by standard venipuncture for biochemical analyses. Flow cytometry was employed to obtain the T helper/T cytotoxic lymphocyte ratio, and insulin resistance was assessed by the HOMA index (HI). Yeasts were isolated from 71 (26%) women: 23 (32.4%) with a positive culture but without symptoms (COL), 22 (31%) in an acute episode (VVC), and 26 (36.6%) with RVVC. C. albicans was the main yeast isolated in all clinical profiles. The control group (negative culture) comprised 206 women. Diabetes mellitus and insulin resistance were more associated with the positive-culture groups (COL, VVC and RVVC) than with negative ones. The RVVC group showed lower mean levels of cortisol than the control group and lower antioxidant capacity than all other groups. The T Helper/T cytotoxic lymphocyte ratio was similar in all groups. The RVVC group showed a similar level of vaginal inflammation to the control group, and lower than in the COL and VVC groups. Only the CVV group showed a reduction in vaginal lactobacillus microbiota. Our data suggest that both chronic stress (decreased early-morning cortisol levels) and reduced antioxidant capacity can be host predisposing factors to RVVC. PMID:27415762

  19. Studies on the Predisposing Factors of Protein Energy Malnutrition Among Pregnant Women in a Nigerian Community

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    Okwu GN

    2008-01-01

    Full Text Available Protein Energy Malnutrition (PEM continues to be a major public health problem in developing countries and affects mostly infants, young children, pregnant and lactating mothers. This study was carried on some of the factors that predispose pregnant women to PEM and hence identify groups at greater risk. A total of 1387 pregnant women (910 in the urban area and 477 in the rural areas were recruited for the study. Anthropometric indices of weight, height and Body Mass Index (BMI of the pregnant women were measured and semi structured questionnaires were used to elicit information on possible predisposing factors such as age, level of education, parity, child spacing etc. Results obtained showed that the mean weight and height of the rural pregnant women, were significantly (p<0.0001 lower than those of the urban pregnant women. The mean BMI of the rural subjects, was also significantly (p< 0.0027 lower than that of the urban subjects. Analysis of the effect of age showed that the younger age category (24 years and below had significantly (p<0.0001 lower mean BMI and higher prevalence of PEM while the effect of level of education showed significantly (p<0006 lower mean BMI and higher PEM prevalence among the less educated (no formal and primary education. Those with parity of two, one and primipara showed significantly (p<0.0175 lower mean BMI while child spacing did not have any significant effect on both mean BMI and prevalence of PEM. The implications of these findings are discussed and recommendations made on how to tackle the problem.

  20. Variation in Telangiectasia Predisposing Genes Is Associated With Overall Radiation Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Tanteles, George A. [Department of Genetics, University of Leicester, Leicester (United Kingdom); Department of Cancer Studies and Molecular Medicine, University Hospitals of Leicester, Leicester Royal Infirmary, Leicester (United Kingdom); Murray, Robert J.S. [Department of Genetics, University of Leicester, Leicester (United Kingdom); Mills, Jamie [Department of Cancer Studies and Molecular Medicine, University Hospitals of Leicester, Leicester Royal Infirmary, Leicester (United Kingdom); Barwell, Julian [Department of Genetics, University of Leicester, Leicester (United Kingdom); Department of Cancer Studies and Molecular Medicine, University Hospitals of Leicester, Leicester Royal Infirmary, Leicester (United Kingdom); Chakraborti, Prabir [Department of Clinical Oncology, Derby Hospitals NHS Foundation Trust, Derby (United Kingdom); Chan, Steve [Department of Clinical Oncology, Nottingham University Hospitals NHS Trust, Nottingham (United Kingdom); Cheung, Kwok-Leung [Division of Breast Surgery, University of Nottingham, Nottingham (United Kingdom); Ennis, Dawn [Department of Clinical Oncology, Derby Hospitals NHS Foundation Trust, Derby (United Kingdom); Khurshid, Nazish [Department of Genetics, University of Leicester, Leicester (United Kingdom); Lambert, Kelly [Department of Breast Surgery, University Hospitals of Leicester, Glenfield Hospital, Leicester (United Kingdom); Machhar, Rohan; Meisuria, Mitul [Department of Genetics, University of Leicester, Leicester (United Kingdom); Osman, Ahmed; Peat, Irene [Department of Cancer Studies and Molecular Medicine, University Hospitals of Leicester, Leicester Royal Infirmary, Leicester (United Kingdom); Sahota, Harjinder [Department of Genetics, University of Leicester, Leicester (United Kingdom); Woodings, Pamela [Department of Clinical Oncology, Derby Hospitals NHS Foundation Trust, Derby (United Kingdom); Talbot, Christopher J., E-mail: cjt14@le.ac.uk [Department of Genetics, University of Leicester, Leicester (United Kingdom); and others

    2012-11-15

    Purpose: In patients receiving radiotherapy for breast cancer where the heart is within the radiation field, cutaneous telangiectasiae could be a marker of potential radiation-induced heart disease. We hypothesized that single nucleotide polymorphisms (SNPs) in genes known to cause heritable telangiectasia-associated disorders could predispose to such late, normal tissue vascular damage. Methods and Materials: The relationship between cutaneous telangiectasia as a late normal tissue radiation injury phenotype in 633 breast cancer patients treated with radiotherapy was examined. Patients were clinically assessed for the presence of cutaneous telangiectasia and genotyped at nine SNPs in three candidate genes. Candidate SNPs were within the endoglin (ENG) and activin A receptor, type II-like 1 (ACVRL1) genes, mutations in which cause hereditary hemorrhagic telangiectasia and the ataxia-telangiectasia mutated (ATM) gene associated with ataxia-telangiectasia. Results: A total of 121 (19.1%) patients exhibited a degree of cutaneous telangiectasiae on clinical examination. Regression was used to examine the associations between the presence of telangiectasiae in patients who underwent breast-conserving surgery, controlling for the effects of boost and known brassiere size (n=388), and individual geno- or haplotypes. Inheritance of ACVRL1 SNPs marginally contributed to the risk of cutaneous telangiectasiae. Haplotypic analysis revealed a stronger association between inheritance of a ATM haplotype and the presence of cutaneous telangiectasiae, fibrosis and overall toxicity. No significant association was observed between telangiectasiae and the coinheritance of the candidate ENG SNPs. Conclusions: Genetic variation in the ATM gene influences reaction to radiotherapy through both vascular damage and increased fibrosis. The predisposing variation in the ATM gene will need to be better defined to optimize it as a predictive marker for assessing radiotherapy late effects.

  1. Highlights Regarding Host Predisposing Factors to Recurrent Vulvovaginal Candidiasis: Chronic Stress and Reduced Antioxidant Capacity.

    Directory of Open Access Journals (Sweden)

    Luciene Akimoto-Gunther

    Full Text Available We studied host factors that could predispose women to develop recurrent vulvovaginal candidiasis (RVVC, including glycemia, insulin resistance, chronic stress, antioxidant capacity, overall immune status, local inflammation and vaginal microbiota. The presence of yeasts in vaginal culture was screened in 277 women, with or without signs and symptoms of VVC and RVVC. The presence of an inflammatory process and microbiota were analyzed through vaginal bacterioscopy and cervical-vaginal cytology, respectively. Fasting-blood samples were collected by standard venipuncture for biochemical analyses. Flow cytometry was employed to obtain the T helper/T cytotoxic lymphocyte ratio, and insulin resistance was assessed by the HOMA index (HI. Yeasts were isolated from 71 (26% women: 23 (32.4% with a positive culture but without symptoms (COL, 22 (31% in an acute episode (VVC, and 26 (36.6% with RVVC. C. albicans was the main yeast isolated in all clinical profiles. The control group (negative culture comprised 206 women. Diabetes mellitus and insulin resistance were more associated with the positive-culture groups (COL, VVC and RVVC than with negative ones. The RVVC group showed lower mean levels of cortisol than the control group and lower antioxidant capacity than all other groups. The T Helper/T cytotoxic lymphocyte ratio was similar in all groups. The RVVC group showed a similar level of vaginal inflammation to the control group, and lower than in the COL and VVC groups. Only the CVV group showed a reduction in vaginal lactobacillus microbiota. Our data suggest that both chronic stress (decreased early-morning cortisol levels and reduced antioxidant capacity can be host predisposing factors to RVVC.

  2. SIMPLIFYING CELIAC DISEASE PREDISPOSING HLA-DQ ALLELES DETERMINATION BY THE REAL TIME PCR METHOD

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    Nicole SELLESKI

    2015-06-01

    Full Text Available Background Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Genetic susceptibility is associated with two sets of alleles, DQA1*05 - DQB1*02 and DQA1*03 - DQB1*03:02, which code for class II MHC DQ2 and DQ8 molecules, respectively. Approximately 90%-95% of celiac patients are HLA-DQ2 positive, and half of the remaining patients are HLA-DQ8 positive. In fact, during a celiac disease diagnostic workup, the absence of these specific DQA and DQB alleles has a near perfect negative predictive value. Objective Improve the detection of celiac disease predisposing alleles by combining the simplicity and sensitivity of real-time PCR (qPCR and melting curve analysis with the specificity of sequence-specific primers (SSP. Methods Amplifications of sequence-specific primers for DQA1*05 (DQ2, DQB1*02 (DQ2, and DQA1*03 (DQ8 were performed by the real time PCR method to determine the presence of each allele in independent reactions. Primers for Human Growth Hormone were used as an internal control. A parallel PCR-SSP protocol was used as a reference method to validate our results. Results Both techniques yielded equal results. From a total of 329 samples the presence of HLA predisposing alleles was determined in 187 (56.8%. One hundred fourteen samples (61% were positive for a single allele, 68 (36.3% for two alleles, and only 5 (2.7% for three alleles. Conclusion Results obtained by qPCR technique were highly reliable with no discordant results when compared with those obtained using PCR-SSP.

  3. Taeniasis in non-descript dogs in Ngorongoro, Tanzania: Prevalence and predisposing factors

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    Emmanuel S. Swai

    2016-03-01

    Full Text Available The prevalence of taeniasis was determined during the period January to April 2013 in a cross-sectional study of non-descript domestic dogs from the livestock–wildlife ecosystem of Ngorongoro, Tanzania. Taeniid eggs were determined by screening faecal samples using the formalin-ether sedimentation technique. Predisposing factors for dog infection were assessed in relation to demographic, husbandry and management data. Of the 205 faecal samples screened, 150 (73.2% were positive for taeniid eggs. The prevalence of dogs harbouring taeniid eggs was 80%, 30.2% and 75.3% in the less than 1 year, 1–3 years and greater than 3 years of age groups, respectively. Age group and sex prevalence in dogs did not differ significantly (P > 0.05, although the females showed a marginally higher prevalence (73.8% in comparison to the males (72.7%. Taeniid eggs were significantly more likely to be found in the faeces of dogs located in Waso (80.6% and Endulen (75% than in Malambo (63.2%, P < 0.05. The study revealed that dogs owned and raised by agro-pastoralists were at a lower risk of acquiring Taenia spp. infection (P = 0.001 than those that were raised by pastoralists. The majority of dog owners were not aware of the predisposing factors and the mode of transmission of taeniids. Dogs were frequently fed on viscera, trimmings and the heads of slaughtered animals, and they were not treated for parasitic infections. The findings of this study indicate that taeniasis is prevalent among non-descript dogs in Ngorongoro, underscoring the need for further research and active surveillance to better understand the transmission cycle of Taenia spp. in a wider geographical area in Tanzania.

  4. Significance of Aurora B overexpression in hepatocellular carcinoma. Aurora B Overexpression in HCC

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    Lin Zhong-Zhe

    2010-08-01

    Full Text Available Abstract Background To investigate the significance of Aurora B expression in hepatocellular carcinoma (HCC. Methods The Aurora B and Aurora A mRNA level was measured in 160 HCCs and the paired nontumorous liver tissues by reverse transcription-polymerase chain reaction. Mutations of the p53 and β-catenin genes were analyzed in 134 and 150 tumors, respectively, by direct sequencing of exon 2 to exon 11 of p53 and exon 3 of β-catenin. Anticancer effects of AZD1152-HQPA, an Aurora B kinase selective inhibitor, were examined in Huh-7 and Hep3B cell lines. Results Aurora B was overexpressed in 98 (61% of 160 HCCs and in all 7 HCC cell lines examined. The overexpression of Aurora B was associated with Aurora A overexpression (P = 0.0003 and p53 mutation (P = 0.002 and was inversely associated with β-catenin mutation (P = 0.002. Aurora B overexpression correlated with worse clinicopathologic characteristics. Multivariate analysis confirmed that Aurora B overexpression was an independent poor prognostic factor, despite its interaction with Aurora A overexpression and mutations of p53 and β-catenin. In Huh-7 and Hep3B cells, AZD1152-HQPA induced proliferation blockade, histone H3 (Ser10 dephosphorylation, cell cycle disturbance, and apoptosis. Conclusion Aurora B overexpression is an independent molecular marker predicting tumor invasiveness and poor prognosis of HCC. Aurora B kinase selective inhibitors are potential therapeutic agents for HCC treatment.

  5. SPONTANEOUS SPINAL EPIDURAL ABSCESS FOLLOWING TRAUMA TO BACK IN A HEALTHY ADULT WITHOUT PREDISPOSING FACTORS - A RARE CASE REPORT

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    Shanmuga Sundaram

    2014-02-01

    Full Text Available Spinal epidural abscess due to its varied presentation , poses a great challenge, more so in a healthy adult, without any predisposing factors. Early diagnosis and treatment is paramount, as late diagnosis and delayed treatment result in increased mortality and morbidity. In this case report, we are presenting a case of spinal extradural abscess in a healthy young adult without predisposing factors, provisionally diagnosed as extradural hematoma and early surgical intervention confirmed the diagnosis of spinal epidural abscess and prevented any devastating consequence

  6. The predisposing factors between dental caries and deviations from normal weight

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    Amandeep Chopra

    2015-01-01

    Full Text Available Background: Dental caries and deviations from normal weight are two conditions which share several broadly predisposing factors. So it′s important to understand any relationship between dental state and body weight if either is to be managed appropriately. Aims: The study was done to find out the correlation between body mass index (BMI, diet, and dental caries among 12-15-year-old schoolgoing children in Panchkula District. Materials and Methods: A multistage sample of 12-15-year-old school children (n = 810 in Panchkula district, Haryana was considered. Child demographic details and diet history for 5 days was recorded. Data regarding dental caries status was collected using World Health Organization (1997 format. BMI was calculated and categorized according to the World Health Organization classification system for BMI. The data were subjected to statistical analysis using chi-square test and binomial regression developed using the Statistical Package for Social Sciences (SPSS 20.0. Results: The mean Decayed Missing Filled Teeth (DMFT score was found to be 1.72 with decayed, missing, and filled teeth to be 1.22, 0.04, and 0.44, respectively. When the sample was assessed based on type of diet, it was found that vegetarians had higher mean DMFT (1.72 as compared to children having mixed diet. Overweight children had highest DMFT (3.21 which was followed by underweight (2.31 and obese children (2.23. Binomial regression revealed that females were 1.293 times at risk of developing caries as compared to males. Fair and poor Simplified-Oral Hygiene Index (OHI-S showed 3.920 and 4.297 times risk of developing caries as compared to good oral hygiene, respectively. Upper high socioeconomic status (SES is at most risk of developing caries. Underweight, overweight, and obese are at 2.7, 2.5, and 3 times risk of developing caries as compared to children with normal BMI, respectively. Conclusion: Dental caries and deviations from normal weight are two

  7. Common variants at the MHC locus and at chromosome 16q24.1 predispose to Barrett's esophagus

    NARCIS (Netherlands)

    Su, Zhan; Gay, Laura J.; Strange, Amy; Palles, Claire; Band, Gavin; Whiteman, David C.; Lescai, Francesco; Langford, Cordelia; Nanji, Manoj; Edkins, Sarah; van der Winkel, Anouk; Levine, David; Sasieni, Peter; Bellenguez, Celine; Howarth, Kimberley; Freeman, Colin; Trudgill, Nigel; Tucker, Art T.; Pirinen, Matti; Peppelenbosch, Maikel P.; van der Laan, Luc J. W.; Kuipers, Ernst J.; Drenth, Joost P. H.; Peters, Wilbert H.; Reynolds, John V.; Kelleher, Dermot P.; McManus, Ross; Grabsch, Heike; Prenen, Hans; Bisschops, Raf; Krishnadath, Kausila; Siersema, Peter D.; van Baal, Jantine W. P. M.; Middleton, Mark; Petty, Russell; Gillies, Richard; Burch, Nicola; Bhandari, Pradeep; Paterson, Stuart; Edwards, Cathryn; Penman, Ian; Vaidya, Kishor; Ang, Yeng; Murray, Iain; Patel, Praful; Ye, Weimin; Mullins, Paul; Wu, Anna H.; Bird, Nigel C.; Dallal, Helen; Shaheen, Nicholas J.; Murray, Liam J.; Koss, Konrad; Bernstein, Leslie; Romero, Yvonne; Hardie, Laura J.; Zhang, Rui; Winter, Helen; Corley, Douglas A.; Panter, Simon; Risch, Harvey A.; Reid, Brian J.; Sargeant, Ian; Gammon, Marilie D.; Smart, Howard; Dhar, Anjan; McMurtry, Hugh; Ali, Haythem; Liu, Geoffrey; Casson, Alan G.; Chow, Wong-Ho; Rutter, Matt; Tawil, Ashref; Morris, Danielle; Nwokolo, Chuka; Isaacs, Peter; Rodgers, Colin; Ragunath, Krish; MacDonald, Chris; Haigh, Chris; Monk, David; Davies, Gareth; Wajed, Saj; Johnston, David; Gibbons, Michael; Cullen, Sue; Church, Nicholas; Langley, Ruth; Griffin, Michael; Alderson, Derek; Deloukas, Panos; Hunt, Sarah E.; Gray, Emma; Dronov, Serge; Potter, Simon C.; Tashakkori-Ghanbaria, Avazeh; Anderson, Mark; Brooks, Claire; Blackwell, Jenefer M.; Bramon, Elvira; Brown, Matthew A.; Casas, Juan P.; Corvin, Aiden; Duncanson, Audrey; Markus, Hugh S.; Mathew, Christopher G.; Palmer, Colin N. A.; Plomin, Robert; Rautanen, Anna; Sawcer, Stephen J.; Trembath, Richard C.; Viswanathan, Ananth C.; Wood, Nicholas; Trynka, Gosia; Wijmenga, Cisca; Cazier, Jean-Baptiste; Atherfold, Paul; Nicholson, Anna M.; Gellatly, Nichola L.; Glancy, Deborah; Cooper, Sheldon C.; Cunningham, David; Lind, Tore; Hapeshi, Julie; Ferry, David; Rathbone, Barrie; Brown, Julia; Love, Sharon; Attwood, Stephen; MacGregor, Stuart; Watson, Peter; Sanders, Scott; Ek, Weronica; Harrison, Rebecca F.; Moayyedi, Paul; de Caestecker, John; Barr, Hugh; Stupka, Elia; Vaughan, Thomas L.; Peltonen, Leena; Spencer, Chris C. A.; Tomlinson, Ian; Donnelly, Peter; Jankowski, Janusz A. Z.

    2012-01-01

    Barrett's esophagus is an increasingly common disease that is strongly associated with reflux of stomach acid and usually a hiatus hernia, and it strongly predisposes to esophageal adenocarcinoma (EAC), a tumor with a very poor prognosis. We report the first genome-wide association study on Barrett'

  8. Phosphoinositide 3-kinase δ gene mutation predisposes to respiratory infection and airway damage

    Science.gov (United States)

    Angulo, Ivan; Vadas, Oscar; Garçon, Fabien; Banham-Hall, Edward; Plagnol, Vincent; Leahy, Timothy R.; Baxendale, Helen; Coulter, Tanya; Curtis, James; Wu, Changxin; Blake-Palmer, Katherine; Perisic, Olga; Smyth, Deborah; Maes, Mailis; Fiddler, Christine; Juss, Jatinder; Cilliers, Deirdre; Markelj, Gašper; Chandra, Anita; Farmer, George; Kielkowska, Anna; Clark, Jonathan; Kracker, Sven; Debré, Marianne; Picard, Capucine; Pellier, Isabelle; Jabado, Nada; Morris, James A.; Barcenas-Morales, Gabriela; Fischer, Alain; Stephens, Len; Hawkins, Phillip; Barrett, Jeffrey C.; Abinun, Mario; Clatworthy, Menna; Durandy, Anne; Doffinger, Rainer; Chilvers, Edwin; Cant, Andrew J.; Kumararatne, Dinakantha; Okkenhaug, Klaus; Williams, Roger L.; Condliffe, Alison; Nejentsev, Sergey

    2014-01-01

    Genetic mutations cause primary immunodeficiencies (PIDs), which predispose to infections. Here we describe Activated PI3K-δ Syndrome (APDS), a PID associated with a dominant gain-of-function mutation E1021K in the p110δ protein, the catalytic subunit of phosphoinositide 3-kinase δ (PI3Kδ), encoded by the PIK3CD gene. We found E1021K in 17 patients from seven unrelated families, but not among 3,346 healthy subjects. APDS was characterized by recurrent respiratory infections, progressive airway damage, lymphopenia, increased circulating transitional B cells, increased IgM and reduced IgG2 levels in serum and impaired vaccine responses. The E1021K mutation enhanced membrane association and kinase activity of p110δ. Patient-derived lymphocytes had increased levels of phosphatidylinositol 3,4,5-trisphosphate and phosphorylated AKT protein and were prone to activation-induced cell death. Selective p110δ inhibitors IC87114 and GS-1101 reduced the activity of the mutant enzyme in vitro, suggesting a therapeutic approach for patients with APDS. PMID:24136356

  9. Helminth infections predispose mice to pneumococcal pneumonia but not to other pneumonic pathogens.

    Science.gov (United States)

    Apiwattanakul, Nopporn; Thomas, Paul G; Kuhn, Raymond E; Herbert, De'Broski R; McCullers, Jonathan A

    2014-10-01

    Pneumonia is the leading killer of children worldwide. Here, we report that helminth-infected mice develop fatal pneumonia when challenged with Streptococcus pneumoniae. Mice were chronically infected with either the flatworm Taenia crassiceps or the roundworm Heligmosomoides polygyrus. Upon challenge with a pneumonic type 3 strain of S. pneumoniae (A66.1), the worm-infected mice developed pneumonia at a rate and to a degree higher than age-matched control mice as measured by bioluminescent imaging and lung titers. This predisposition to pneumonia appears to be specific to S. pneumoniae, as worm-infected mice did not show evidence of increased morbidity when challenged with a lethal dose of influenza virus or sublethal doses of Staphylococcus aureus or Listeria monocytogenes. The defect was also present when worm-infected mice were challenged with a type 2 sepsis-causing strain (D39); an increased rate of pneumonia, decreased survival, and increased lung and blood titers were found. Pneumococcal colonization and immunity against acute otitis media were unaffected. Anti-helminthic treatment in the H. polygyrus model reversed this susceptibility. We conclude that helminth coinfection predisposes mice to fatal pneumococcal pneumonia by promoting increased outgrowth of bacteria in the lungs and blood. These data have broad implications for the prevention and treatment for pneumonia in the developing world, where helminth infections are endemic and pneumococcal pneumonia is common.

  10. Haploinsufficiency of the ESCRT Component HD-PTP Predisposes to Cancer

    Directory of Open Access Journals (Sweden)

    Sanaz Manteghi

    2016-05-01

    Full Text Available Endosomal sorting complexes required for transport (ESCRT drive cell surface receptor degradation resulting in attenuation of oncogenic signaling and pointing to a tumor suppressor function. Here, we show that loss of function of an ESCRT protein (HD-PTP encoded by the PTPN23 gene, located on the tumor suppressor gene cluster 3p21.3 drives tumorigenesis in vivo. Indeed, Ptpn23+/− loss predisposes mice to sporadic lung adenoma, B cell lymphoma, and promotes Myc-driven lymphoma onset, dissemination, and aggressiveness. Ptpn23+/−-derived tumors exhibit an unaltered remaining allele and maintain 50% of HD-PTP expression. Consistent with the role of HD-PTP in attenuation of integrin recycling, cell migration, and invasion, hemizygous Ptpn23+/− loss increases integrin β1-dependent B cell lymphoma survival and dissemination. Finally, we reveal frequent PTPN23 deletion and downregulation in human tumors that correlates with poor survival. Altogether, we establish HD-PTP/PTPN23 as a prominent haploinsufficient tumor suppressor gene preventing tumor progression through control of integrin trafficking.

  11. TGFBR2 mutations alter smooth muscle cell phenotype and predispose to thoracic aortic aneurysms and dissections

    Science.gov (United States)

    Inamoto, Sakiko; Kwartler, Callie S.; Lafont, Andrea L.; Liang, Yao Yun; Fadulu, Van Tran; Duraisamy, Senthil; Willing, Marcia; Estrera, Anthony; Safi, Hazim; Hannibal, Mark C.; Carey, John; Wiktorowicz, John; Tan, Filemon K.; Feng, Xin-Hua; Pannu, Hariyadarshi; Milewicz, Dianna M.

    2010-01-01

    Aims Transforming growth factor-β (TGF-β) signaling is critical for the differentiation of smooth muscle cells (SMCs) into quiescent cells expressing a full repertoire of contractile proteins. Heterozygous mutations in TGF-β receptor type II (TGFBR2) disrupt TGF-β signaling and lead to genetic conditions that predispose to thoracic aortic aneurysms and dissections (TAADs). The aim of this study is to determine the molecular mechanism by which TGFBR2 mutations cause TAADs. Methods and results Using aortic SMCs explanted from patients with TGFBR2 mutations, we show decreased expression of SMC contractile proteins compared with controls. Exposure to TGF-β1 fails to increase expression of contractile genes in mutant SMCs, whereas control cells further increase expression of these genes. Analysis of fixed and frozen aortas from patients with TGFBR2 mutations confirms decreased in vivo expression of contractile proteins relative to unaffected aortas. Fibroblasts explanted from patients with TGFBR2 mutations fail to transform into mature myofibroblasts with TGF-β1 stimulation as assessed by expression of contractile proteins. Conclusions These data support the conclusion that heterozygous TGFBR2 mutations lead to decreased expression of SMC contractile protein in both SMCs and myofibroblasts. The failure of TGFBR2-mutant SMCs to fully express SMC contractile proteins predicts defective contractile function in these cells and aligns with a hypothesis that defective SMC contractile function contributes to the pathogenesis of TAAD. PMID:20628007

  12. Dietary zinc deficiency predisposes mice to the development of preneoplastic lesions in chemically-induced hepatocarcinogenesis.

    Science.gov (United States)

    Romualdo, Guilherme Ribeiro; Goto, Renata Leme; Henrique Fernandes, Ana Angélica; Cogliati, Bruno; Barbisan, Luis Fernando

    2016-10-01

    Although there is a concomitance of zinc deficiency and high incidence/mortality for hepatocellular carcinoma in certain human populations, there are no experimental studies investigating the modifying effects of zinc on hepatocarcinogenesis. Thus, we evaluated whether dietary zinc deficiency or supplementation alter the development of hepatocellular preneoplastic lesions (PNL). Therefore, neonatal male Balb/C mice were submitted to a diethylnitrosamine/2-acetylaminefluorene-induced hepatocarcinogenesis model. Moreover, mice were fed adequate (35 mg/kg diet), deficient (3 mg/kg) or supplemented (180 mg/kg) zinc diets. Mice were euthanized at 12 (early time-point) or 24 weeks (late time-point) after introducing the diets. At the early time-point, zinc deficiency decreased Nrf2 protein expression and GSH levels while increased p65 and p53 protein expression and the number of PNL/area. At the late time-point, zinc deficiency also decreased GSH levels while increased liver genotoxicity, cell proliferation into PNL and PNL size. In contrast, zinc supplementation increased antioxidant defense at both time-points but not altered PNL development. Our findings are the first to suggest that zinc deficiency predisposes mice to the PNL development in chemically-induced hepatocarcinogenesis. The decrease of Nrf2/GSH pathway and increase of liver genotoxicity, as well as the increase of p65/cell proliferation, are potential mechanisms to this zinc deficiency-mediated effect.

  13. Status of Taenia solium cysticercosis and predisposing factors in developing countries involved in pig farming

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    Joseph M. Kungu

    2015-05-01

    Full Text Available Taenia solium cysticercosis is a disease of pigs and humans populations considered endemic in many developing countries of Latin America, Africa, and South East Asia having serious impact on public health and agriculture. We conducted an in-depth comparative analysis of literature on the disease situation and predisposing factors in selected countries known to be at the interface of poverty-emerging livestock systems-zoonoses and with a growing small holder pig industry. Transmission, methods of diagnosis and employed control strategies of T. solium infection in pig and human populations in these countries are also discussed. Limited knowledge on porcine cysticercosis (PC by various stakeholders expected to be key players in its control has undermined efforts for eliminating this potentially eradicable condition. Poor pig production practices, poor hygiene, and sanitation habits have also been important in the maintenance of the T. solium life-cycle. The major gaps identified in this review include scanty current information on PC prevalence in pigs with hardly any reports on the condition in humans in most developing countries. Factors affecting pattern of the infection and how they interact at the different levels of the pig value chain have not been exhaustively studied. Information on socioeconomic and public health impact is inadequate and not current.

  14. Sex differences in soleus strength may predispose middle age women to falls.

    Science.gov (United States)

    Chimera, Nicole J; Manal, Kurt T

    2013-09-01

    This study investigated middle age healthy adults to elucidate if plantar flexion (PF) strength differences exist because of the triceps surae or the soleus when comparing between sexes. A random population sample was stratified by sex and included 25 healthy (12 women and 13 men) subjects who volunteered for participation. Dorsiflexion range of motion was measured using a biplane goniometer. Self-reported function was assessed using the Foot and Ankle Ability Measure. Ankle PF strength was assessed using the Biodex System 3. To determine triceps surae vs. soleus strength, testing positions included (1) full ankle dorsiflexion with the knee in full extension and (2) full ankle dorsiflexion with 90° of knee flexion. Results indicated that women were significantly weaker than men in absolute PF strength for both triceps surae and soleus testing positions. Furthermore, even with normalizing PF strength to body mass PF strength deficits persisted. Additionally, when the contribution of the soleus was accounted for in the full knee extended position (triceps surae), normalized strength differences no longer existed between sexes. Therefore, these results indicate that what appeared as triceps surae complex strength deficits in middle age women compared with men was actually soleus weakness. This may suggest that middle age women are predisposed to increased falls at an early age than previously reported. Additionally, this may indicate that the soleus muscle should be a focus of strength training for women during middle age.

  15. Discrete deposition of hydroxyapatite nanoparticles on a titanium implant with predisposing substrate microtopography accelerated osseointegration

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Ichiro [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Huang Yuhong [Chemat Technology, Incorporated, Northridge, CA (United States); Butz, Frank [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Ogawa, Takahiro [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Lin, Audrey [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Wang, Chiachien Jake [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States)

    2007-06-20

    We report here a new versatile method to deposit discrete hydroxyapatite (HA) nanoparticles on a titanium (Ti) implant with predisposing substrate microtopography, which exhibited an unexpectedly robust biological effect. Commercially pure Ti substrates were treated with 3-aminopropyltriethoxysilane, on which HA nanoparticles (20 nm) were deposited and chemically bonded to TiO{sub 2}. The HA deposition rate was linearly related to the treatment time and HA nanoparticles were deposited on up to 50% of the substrate surface. As a result, the discrete deposition of HA nanoparticles generated novel 20-40 nm nanotopography on the Ti substrate with microtopography that was smooth (turned) or roughened by double acid etching (DAE). The experimental implants with or without HA nanoparticles were surgically placed in rat femur and an implant push-in test was performed after two weeks of healing. The deposition of HA nanoparticles on the DAE surface increased the mechanical withstanding load by 129% and 782% as compared to the control DAE and turned implants, respectively. Micro-computed tomography-based 3D bone morphometry revealed equivalent bone volumes around the DAE implant with or without HA nanoparticles. These data suggest that the discrete deposition of HA nanoparticles accelerates the early osseointegration process, likely through increased shear bonding strengths.

  16. Incisional Hernia in Women: Predisposing Factors and Management Where Mesh is Not Readily Available

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    E Agbakwuru

    2009-01-01

    Full Text Available Background / Aim: Incisional hernia is still relatively common in our practice. The aim of the studywas to identify risk factors associated with incisional hernia in our region. The setting is the ObafemiAwolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria during a period when prostheticmesh was not readily available. Patients and Methods: All the women who presented with incisionalhernia between 1996 and 2005 were prospectively studied using a standard form to obtaininformation on pre-hernia (index operations and possible predisposing factors. They all had opensurgical repair and were followed up for 18-60 months. Results: Forty-four women were treatedduring study period. The index surgeries leading to the hernias were emergency caesarian section26/44 (59.1%, emergency exploratory laparotomy 6/44 (13.6%, and elective surgeries 12/44(27.3%. Major associated risk factors were the use of wrong suture materials for fascia repair, midlineincisions, wound sepsis, and overweight. Conclusion: For elective surgeries, reduction of weightshould be encouraged when appropriate, and transverse incisions are preferred. Absorbable sutures,especially chromic catgut, should be avoided in fascia closure. Antibiotics should be used forcomplicated obstetric cases.

  17. Constitutional abnormalities of chromosome 21 predispose to iAMP21-acute lymphoblastic leukaemia.

    Science.gov (United States)

    Harrison, Christine J; Schwab, Claire

    2016-03-01

    In addition to Down syndrome, individuals with other constitutional abnormalities of chromosome 21 have an increased risk of developing childhood acute lymphoblastic leukaemia (ALL). Specifically, carriers of the Robertsonian translocation between chromosomes 15 and 21, rob(15;21) (q10; q10)c, have ∼2,700 increased risk of developing ALL with iAMP21 (intrachromosomal amplification of chromosome 21). In these patients, chromosome 15 as well as chromosome 21 is involved in the formation of iAMP21, referred to here as der(21)(15;21). Individuals with constitutional ring chromosomes involving chromosome 21, r(21)c, are also predisposed to iAMP21-ALL, involving the same series of mutational processes as seen in sporadic- and der(21)(15;21)-iAMP21 ALL. Evidence is accumulating that the dicentric nature of the Robertsonian and ring chromosome is the initiating factor in the formation of the complex iAMP21 structure. Unravelling these intriguing predispositions to iAMP21-ALL may provide insight into how other complex rearrangements arise in cancer.

  18. Predisposing factors for renal scarring in children with urinary tract infection

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    Fatemeh Beiraghdar

    2012-01-01

    Full Text Available This study was undertaken to determine the predisposing factors for renal scarring in children with urinary tract infection. In this prospective cohort study, 176 children with documented urinary tract infection were categorized into four groups: ≤1 year old, 1-2 years old, 2-7 years and 7-14 years old. Ultrasonography and Technetium-99 m-DMSA scan were used to detect the possible abnormalities. Infants under 12 months old presented as the most common group for renal scarring (27 cases, 52.9%, and vesicoureteral reflux (VUR was diagnosed in 29 cases (56.8%. Fifteen (41.67% children between the ages of one and two years had renal scar, and VUR was detected in half of the patients. In the third group, 36.3%, and in fourth group, 41.6% of the patients had renal scar. Also, 38.6% in group three and 50% in the final group had VUR. A co-incidental finding that was observed in this study was the high incidence of pseudohypoaldesteronism (PHA in our patients: in 39.2% of the children in group one, 22.2% in group two and 4% in group three. In group four however, none of the patients had PHA. Risk of scar formation with urinary tract infection (UTI was higher in the younger age group and in those with recurrent UTIs.

  19. Predictive genetic testing in children: constitutional mismatch repair deficiency cancer predisposing syndrome.

    Science.gov (United States)

    Bruwer, Zandrè; Algar, Ursula; Vorster, Alvera; Fieggen, Karen; Davidson, Alan; Goldberg, Paul; Wainwright, Helen; Ramesar, Rajkumar

    2014-04-01

    Biallelic germline mutations in mismatch repair genes predispose to constitutional mismatch repair deficiency syndrome (CMMR-D). The condition is characterized by a broad spectrum of early-onset tumors, including hematological, brain and bowel and is frequently associated with features of Neurofibromatosis type 1. Few definitive screening recommendations have been suggested and no published reports have described predictive testing. We report on the first case of predictive testing for CMMR-D following the identification of two non-consanguineous parents, with the same heterozygous mutation in MLH1: c.1528C > T. The genetic counseling offered to the family, for their two at-risk daughters, is discussed with a focus on the ethical considerations of testing children for known cancer-causing variants. The challenges that are encountered when reporting on heterozygosity in a child younger than 18 years (disclosure of carrier status and risk for Lynch syndrome), when discovered during testing for homozygosity, are addressed. In addition, the identification of CMMR-D in a three year old, and the recommended clinical surveillance that was proposed for this individual is discussed. Despite predictive testing and presymptomatic screening, the sudden death of the child with CMMR-D syndrome occurred 6 months after her last surveillance MRI. This report further highlights the difficulty of developing guidelines, as a result of the rarity of cases and diversity of presentation.

  20. Taeniasis in non-descript dogs in Ngorongoro, Tanzania: Prevalence and predisposing factors.

    Science.gov (United States)

    Swai, Emmanuel S; Miran, Miran B; Kasuku, Ayubu A; Nzalawahe, Jahashi

    2016-05-24

    The prevalence of taeniasis was determined during the period January to April 2013 in a cross-sectional study of non-descript domestic dogs from the livestock-wildlife ecosystem of Ngorongoro, Tanzania. Taeniid eggs were determined by screening faecal samples using the formalin-ether sedimentation technique. Predisposing factors for dog infection were assessed in relation to demographic, husbandry and management data. Of the 205 faecal samples screened, 150 (73.2%) were positive for taeniid eggs. The prevalence of dogs harbouring taeniid eggs was 80%, 30.2% and 75.3% in the less than 1 year, 1-3 years and greater than 3 years of age groups, respectively. Age group and sex prevalence in dogs did not differ significantly (P > 0.05), although the females showed a marginally higher prevalence (73.8%) in comparison to the males (72.7%). Taeniid eggs were significantly more likely to be found in the faeces of dogs located in Waso (80.6%) and Endulen (75%) than in Malambo (63.2%, P taeniasis is prevalent among non-descript dogs in Ngorongoro, underscoring the need for further research and active surveillance to better understand the transmission cycle of Taenia spp. in a wider geographical area in Tanzania.

  1. A BAP1 mutation in a Danish family predisposes to uveal melanoma and other cancers.

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    Lauren G Aoude

    Full Text Available Truncating germline mutations in the tumor suppressor gene BRCA-1 associated protein-1 (BAP1 have been reported in families predisposed to developing a wide range of different cancer types including uveal melanoma and cutaneous melanoma. There has also been an association between amelanotic tumor development and germline BAP1 mutation suggesting a possible phenotypic characteristic of BAP1 mutation carriers. Though there have been many types of cancer associated with germline BAP1 mutation, the full spectrum of disease association is yet to be ascertained. Here we describe a Danish family with predominantly uveal melanoma but also a range of other tumor types including lung, neuroendocrine, stomach, and breast cancer; as well as pigmented skin lesions. Whole-exome sequencing identified a BAP1 splice mutation located at c.581-2A>G, which leads to a premature truncation of BAP1 in an individual with uveal melanoma. This mutation was carried by several other family members with melanoma or various cancers. The finding expands on the growing profile of BAP1 as an important uveal and cutaneous melanoma tumor suppressor gene and implicates its involvement in the development of lung, and stomach cancer.

  2. Mutations in complement regulatory proteins predispose to preeclampsia: a genetic analysis of the PROMISSE cohort.

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    Jane E Salmon

    2011-03-01

    Full Text Available BACKGROUND: Pregnancy in women with systemic lupus erythematosus (SLE or antiphospholipid antibodies (APL Ab--autoimmune conditions characterized by complement-mediated injury--is associated with increased risk of preeclampsia and miscarriage. Our previous studies in mice indicate that complement activation targeted to the placenta drives angiogenic imbalance and placental insufficiency. METHODS AND FINDINGS: We use PROMISSE, a prospective study of 250 pregnant patients with SLE and/or APL Ab, to test the hypothesis in humans that impaired capacity to limit complement activation predisposes to preeclampsia. We sequenced genes encoding three complement regulatory proteins--membrane cofactor protein (MCP, complement factor I (CFI, and complement factor H (CFH--in 40 patients who had preeclampsia and found heterozygous mutations in seven (18%. Five of these patients had risk variants in MCP or CFI that were previously identified in atypical hemolytic uremic syndrome, a disease characterized by endothelial damage. One had a novel mutation in MCP that impairs regulation of C4b. These findings constitute, to our knowledge, the first genetic defects associated with preeclampsia in SLE and/or APL Ab. We confirmed the association of hypomorphic variants of MCP and CFI in a cohort of non-autoimmune preeclampsia patients in which five of 59 were heterozygous for mutations. CONCLUSION: The presence of risk variants in complement regulatory proteins in patients with SLE and/or APL Ab who develop preeclampsia, as well as in preeclampsia patients lacking autoimmune disease, links complement activation to disease pathogenesis and suggests new targets for treatment of this important public health problem. STUDY REGISTRATION: ClinicalTrials.gov NCT00198068.

  3. 痤疮易感基因的研究进展%Predisposing genes in acne

    Institute of Scientific and Technical Information of China (English)

    杨小燕; 何黎

    2011-01-01

    痤疮是发生于毛囊皮脂腺的一种慢性炎症性疾病,发病机制尚不完全清楚.目前认为,主要与雄激素、皮脂分泌增多、毛囊导管的异常角化、痤疮丙酸杆菌感染、外界因素、机体的免疫反应和遗传有关.近年来研究表明,痤疮是一种多基因遗传病,尤其是重型痤疮与遗传密切相关.CYP11α、CYP17、CYP1A1、雄激素受体基因、CYP21等基因被认为是痤疮易感基因.因此,探讨痤疮的易感基因,对痤疮尤其是重型痤疮的早期诊断、治疗和预防具有重要意义.%Acne is a common chronic inflammatory disease affecting hair follicles and sebaceous glands with unclear pathogenesis. It is a multifactorial disease and several pathogenetic factors have been identified, including the increase of androgen and sebum excretion, follicular hyperkeratinization, infection with Propionibacterium acnes, external factors, innate immunity, genetics, etc. Latest studies have indicated that acne is a polygenic disease and there is a particularly close correlation between severe acne and heredity. Many predisposing genes have been discovered for acne, including human CYP11α gene, CYP17 gene, CYP1A1gene, androgen receptor gene, CYP21 gene, etc. Therefore, the investigation into susceptible genes for acne may be beneficial to the early diagnosis, treatment and prevention of severe acne.

  4. Fumonisins affect the intestinal microbial homeostasis in broiler chickens, predisposing to necrotic enteritis.

    Science.gov (United States)

    Antonissen, Gunther; Croubels, Siska; Pasmans, Frank; Ducatelle, Richard; Eeckhaut, Venessa; Devreese, Mathias; Verlinden, Marc; Haesebrouck, Freddy; Eeckhout, Mia; De Saeger, Sarah; Antlinger, Birgit; Novak, Barbara; Martel, An; Van Immerseel, Filip

    2015-09-23

    Fumonisins (FBs) are mycotoxins produced by Fusarium fungi. This study aimed to investigate the effect of these feed contaminants on the intestinal morphology and microbiota composition, and to evaluate whether FBs predispose broilers to necrotic enteritis. One-day-old broiler chicks were divided into a group fed a control diet, and a group fed a FBs contaminated diet (18.6 mg FB1+FB2/kg feed). A significant increase in the plasma sphinganine/sphingosine ratio in the FBs-treated group (0.21 ± 0.016) compared to the control (0.14 ± 0.014) indicated disturbance of the sphingolipid biosynthesis. Furthermore, villus height and crypt depth of the ileum was significantly reduced by FBs. Denaturing gradient gel electrophoresis showed a shift in the microbiota composition in the ileum in the FBs group compared to the control. A reduced presence of low-GC containing operational taxonomic units in ileal digesta of birds exposed to FBs was demonstrated, and identified as a reduced abundance of Candidatus Savagella and Lactobaccilus spp. Quantification of total Clostridium perfringens in these ileal samples, previous to experimental infection, using cpa gene (alpha toxin) quantification by qPCR showed an increase in C. perfringens in chickens fed a FBs contaminated diet compared to control (7.5 ± 0.30 versus 6.3 ± 0.24 log10 copies/g intestinal content). After C. perfringens challenge, a higher percentage of birds developed subclinical necrotic enteritis in the group fed a FBs contaminated diet as compared to the control (44.9 ± 2.22% versus 29.8 ± 5.46%).

  5. Pre-exposure to ozone predisposes oak leaves to attacks by Diplodia corticola and Biscogniauxia mediterranea.

    Science.gov (United States)

    Paoletti, Elena; Anselmi, Naldo; Franceschini, Antonio

    2007-01-01

    One-year-old cork oak (Quercus suber) and turkey oak (Q. cerris) seedlings were exposed to ozone (110 ppb, 5 h day(-1), for 30 days) and were inoculated with Diplodia corticola and Biscogniauxia mediterranea, respectively, by spraying a suspension of spores on the leaves. Both fungi are endophytic and may act as weak parasites, contributing to oak decline. Ozone exposure stimulated leaf attacks after inoculation, although the physiological, visible, and structural responses of both oaks to O3 exposure were weak. In fact, steady-state gas exchange, leaf waxes, and wettability were not significantly affected by O3. In Q. cerris, O3 altered the structure of stomata, as observed by scanning microscopy, and reduced the leaf relative water content. No hyphal entry through stomata or growth towards stomata was, however, observed. Inoculations were performed in a humid chamber at low light; stomata were likely to be closed. When Q. cerris was inoculated in natural conditions, i.e., in a forest infected by B. mediterranea, seedlings pre-exposed to the enhanced O3 regime had a higher number of B. mediterranea isolates than the controls. This suggests that pre-exposure to O3 predisposed Q. cerris leaves to attacks by B. mediterranea independent of stomata. The hyphae of both fungi were able to enter the leaf through the cuticle, either by gradual in-growth into the cuticle or erosion of a hollow in the cuticle at the point of contact. The primary cause of increased leaf injury in O3-exposed seedlings appeared to be higher germination of spores than on control leaves.

  6. Early severe inflammatory responses to uropathogenic E. coli predispose to chronic and recurrent urinary tract infection.

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    Thomas J Hannan

    Full Text Available Chronic infections are an increasing problem due to the aging population and the increase in antibiotic resistant organisms. Therefore, understanding the host-pathogen interactions that result in chronic infection is of great importance. Here, we investigate the molecular basis of chronic bacterial cystitis. We establish that introduction of uropathogenic E. coli (UPEC into the bladders of C3H mice results in two distinct disease outcomes: resolution of acute infection or development of chronic cystitis lasting months. The incidence of chronic cystitis is both host strain and infectious dose-dependent. Further, development of chronic cystitis is preceded by biomarkers of local and systemic acute inflammation at 24 hours post-infection, including severe pyuria and bladder inflammation with mucosal injury, and a distinct serum cytokine signature consisting of elevated IL-5, IL-6, G-CSF, and the IL-8 analog KC. Mice deficient in TLR4 signaling or lymphocytes lack these innate responses and are resistant, to varying degrees, to developing chronic cystitis. Treatment of C3H mice with the glucocorticoid anti-inflammatory drug dexamethasone prior to UPEC infection also suppresses the development of chronic cystitis. Finally, individuals with a history of chronic cystitis, lasting at least 14 days, are significantly more susceptible to redeveloping severe, chronic cystitis upon bacterial challenge. Thus, we have discovered that the development of chronic cystitis in C3H mice by UPEC is facilitated by severe acute inflammatory responses early in infection, which subsequently are predisposing to recurrent cystitis, an insidious problem in women. Overall, these results have significant implications for our understanding of how early host-pathogen interactions at the mucosal surface determines the fate of disease.

  7. Why do young women smoke? III. Attention and impulsivity as neurocognitive predisposing factors.

    Science.gov (United States)

    Yakir, Avi; Rigbi, Amihai; Kanyas, Kyra; Pollak, Yehudah; Kahana, Gazit; Karni, Osnat; Eitan, Renana; Kertzman, Semion; Lerer, Bernard

    2007-04-01

    Since nicotine has been shown to facilitate sustained attention and control of impulsivity, impairment in these domains may influence individuals who initiate smoking for various reasons to continue to smoke cigarettes. The purpose of this study was to determine whether young women who smoke regularly but are not abstinent at the time of testing, differ in their cognitive functioning from non-smokers and whether they resemble women who smoked in the past but quit. Female undergraduate students aged 20-30 years were recruited by advertisement from institutes of higher education in the Jerusalem area. The study sample consisted of 91 current smokers (CS), 40 past smokers (PS) and 151 non-smokers (NS). 46 occasional smokers (OS) were also tested. Confounding by withdrawal state was neutralized by including only CS and OS who smoked their last cigarette less than 90 min before testing. Subjects performed a computerized neurocognitive battery, which tests the domains of attention, memory, impulsivity, planning, information processing and motor performance. Analyses were controlled for age. The results showed that CS made significantly more errors than NS on the Continuous Performance Task (CPT), Matching Familiar Figures Test (MFFT) and Tower of London (TOL) test. PS were significantly worse than NS on the MFFT and TOL test. PS did not differ significantly from CS on any test. No association was found between duration of smoking and performance. These findings suggest that a neurocognitive profile characterized by impairments in sustained attention and control of impulsivity may be one of the factors that predispose young women who initiate cigarette smoking to maintain the habit.

  8. CARDIAC RUPTURE IN MYOCARDIAL INFARCTION: INCIDENCE AND PREDISPOSING FACTORS (15 YEAR FOLLOW-UP

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    V. A. Shulman

    2015-12-01

    Full Text Available Aim. To evaluate the incidence of cardiac rupture (CR in patients with acute myocardial infarction (MI as well as predisposing factors during 15-year follow-up.Material and methods. 1453 patients with acute MI who were admitted to Krasnoyarsk cardiological center during 1989, 1993 and 2003 years were studied. All patients were divided into three groups: group I - 447 patients, who were on treatment in 1989, group II - 475 patients of 1993, and group III – 531 patients of 2003. There were no differences in groups on patient sex, location and depth of MI, previous MI, arrhythmias, heart failure and diabetes mellitus.Results. CR was found in 18 of 447 patients (4% of group I (1989, in 16 of 475 patients (3,4% of group II (1993 and in 10 of 531 patients (1,9% of group 3 (2003, (p1,3 <0,05. Incidence of CR significantly decreased from 1989 to 2003 in female patients (7,2%; 5,7% and 1,6% in 1989, 1993 and 2003, respectively; p1,3 < 0,01, p2,3 < 0,05. Incidence of CR in male patients didn’t changed (2,5%, 1,8% and 2,1%, respectively. The average blood pressure (BP during the first day of MI in female patients was higher than this in male ones in 1989 and 1993. There were no significant differences in BP between women and men in 2003. Heart rate (HR during the first day of MI in female patients was higher than this in male patients in 1989. However in 1993 and 2003 there were no differences in HR between women and men. MI therapy more often included betablockers, angiotensin converting enzyme inhibitors, intravenous nitrates, statins, thrombolythics and anticoagulants in 2003 than in 1989 and 1993.Conclusion. Effective BP and HR control is the most effective way to prevent CR in patients with MI.

  9. CARDIAC RUPTURE IN MYOCARDIAL INFARCTION: INCIDENCE AND PREDISPOSING FACTORS (15 YEAR FOLLOW-UP

    Directory of Open Access Journals (Sweden)

    V. A. Shulman

    2007-01-01

    Full Text Available Aim. To evaluate the incidence of cardiac rupture (CR in patients with acute myocardial infarction (MI as well as predisposing factors during 15-year follow-up.Material and methods. 1453 patients with acute MI who were admitted to Krasnoyarsk cardiological center during 1989, 1993 and 2003 years were studied. All patients were divided into three groups: group I - 447 patients, who were on treatment in 1989, group II - 475 patients of 1993, and group III – 531 patients of 2003. There were no differences in groups on patient sex, location and depth of MI, previous MI, arrhythmias, heart failure and diabetes mellitus.Results. CR was found in 18 of 447 patients (4% of group I (1989, in 16 of 475 patients (3,4% of group II (1993 and in 10 of 531 patients (1,9% of group 3 (2003, (p1,3 <0,05. Incidence of CR significantly decreased from 1989 to 2003 in female patients (7,2%; 5,7% and 1,6% in 1989, 1993 and 2003, respectively; p1,3 < 0,01, p2,3 < 0,05. Incidence of CR in male patients didn’t changed (2,5%, 1,8% and 2,1%, respectively. The average blood pressure (BP during the first day of MI in female patients was higher than this in male ones in 1989 and 1993. There were no significant differences in BP between women and men in 2003. Heart rate (HR during the first day of MI in female patients was higher than this in male patients in 1989. However in 1993 and 2003 there were no differences in HR between women and men. MI therapy more often included betablockers, angiotensin converting enzyme inhibitors, intravenous nitrates, statins, thrombolythics and anticoagulants in 2003 than in 1989 and 1993.Conclusion. Effective BP and HR control is the most effective way to prevent CR in patients with MI.

  10. Urine Stasis Predisposes to Urinary Tract Infection by an Opportunistic Uropathogen in the Megabladder (Mgb Mouse.

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    Brian Becknell

    Full Text Available Urinary stasis is a risk factor for recurrent urinary tract infection (UTI. Homozygous mutant Megabladder (Mgb-/- mice exhibit incomplete bladder emptying as a consequence of congenital detrusor aplasia. We hypothesize that this predisposes Mgb-/- mice to spontaneous and experimental UTI.Mgb-/-, Mgb+/-, and wild-type female mice underwent serial ultrasound and urine cultures at 4, 6, and 8 weeks to detect spontaneous UTI. Urine bacterial isolates were analyzed by Gram stain and speciated. Bladder stones were analyzed by x-ray diffractometry. Bladders and kidneys were subject to histologic analysis. The pathogenicity of coagulase-negative Staphylococcus (CONS isolated from Mgb-/- urine was tested by transurethral administration to culture-negative Mgb-/- or wild-type animals. The contribution of urinary stasis to CONS susceptibility was evaluated by cutaneous vesicostomy in Mgb-/- mice.Mgb-/- mice develop spontaneous bacteriuria (42% and struvite bladder stones (31% by 8 weeks, findings absent in Mgb+/- and wild-type controls. CONS was cultured as a solitary isolate from Mgb-/- bladder stones. Bladders and kidneys from mice with struvite stones exhibit mucosal injury, inflammation, and fibrosis. These pathologic features of cystitis and pyelonephritis are replicated by transurethral inoculation of CONS in culture-negative Mgb-/- females, whereas wild-type animals are less susceptible to CONS colonization and organ injury. Cutaneous vesicostomy prior to CONS inoculation significantly reduces the quantity of CONS recovered from Mgb-/- urine, bladders, and kidneys.CONS is an opportunistic uropathogen in the setting of urinary stasis, leading to enhanced UTI incidence and severity in Mgb-/- mice.

  11. Urine Stasis Predisposes to Urinary Tract Infection by an Opportunistic Uropathogen in the Megabladder (Mgb) Mouse

    Science.gov (United States)

    Becknell, Brian; Mohamed, Ahmad Z.; Li, Birong; Wilhide, Michael E.; Ingraham, Susan E.

    2015-01-01

    Purpose Urinary stasis is a risk factor for recurrent urinary tract infection (UTI). Homozygous mutant Megabladder (Mgb-/-) mice exhibit incomplete bladder emptying as a consequence of congenital detrusor aplasia. We hypothesize that this predisposes Mgb-/- mice to spontaneous and experimental UTI. Methods Mgb-/-, Mgb+/-, and wild-type female mice underwent serial ultrasound and urine cultures at 4, 6, and 8 weeks to detect spontaneous UTI. Urine bacterial isolates were analyzed by Gram stain and speciated. Bladder stones were analyzed by x-ray diffractometry. Bladders and kidneys were subject to histologic analysis. The pathogenicity of coagulase-negative Staphylococcus (CONS) isolated from Mgb-/- urine was tested by transurethral administration to culture-negative Mgb-/- or wild-type animals. The contribution of urinary stasis to CONS susceptibility was evaluated by cutaneous vesicostomy in Mgb-/- mice. Results Mgb-/- mice develop spontaneous bacteriuria (42%) and struvite bladder stones (31%) by 8 weeks, findings absent in Mgb+/- and wild-type controls. CONS was cultured as a solitary isolate from Mgb-/- bladder stones. Bladders and kidneys from mice with struvite stones exhibit mucosal injury, inflammation, and fibrosis. These pathologic features of cystitis and pyelonephritis are replicated by transurethral inoculation of CONS in culture-negative Mgb-/- females, whereas wild-type animals are less susceptible to CONS colonization and organ injury. Cutaneous vesicostomy prior to CONS inoculation significantly reduces the quantity of CONS recovered from Mgb-/- urine, bladders, and kidneys. Conclusions CONS is an opportunistic uropathogen in the setting of urinary stasis, leading to enhanced UTI incidence and severity in Mgb-/- mice. PMID:26401845

  12. [Predisposing factors, clinical picture and mortality in volvulus of the small intestine].

    Science.gov (United States)

    Díaz Plasencia, J; Huaynalaya, E; Rodríguez, F; Rebaza, H

    1992-01-01

    This retrospective study evaluated predisposing factors, clinical picture and the methods of treatment related to morbidity and mortality of 19 small bowel volvulus (SBV) who underwent operation at Belen Hospital (Trujillo-Peru) during the last 26 years (1966-1992). The SBV was 1.6% of all cases of intestinal obstruction in this period and 10.8% of all intestinal volvulus. The median age was of 43 +/- 20.5 years (range, 6 to 78 years) and the majority of them were between 41 and 60 years. Sixteen cases (84.2%) were men from Indian and Spanish extraction and most of them were farmers and came from the Sierra of the Department of La Libertad. Two cases (10.5%) had non-related antecedents previous surgery. In six patients (31.6%) the volvulus was less than seven day's duration and in thirty (68.4%) it was more eight day's duration with previous attacks of obstruction (median: 19.3 days, range: 17 hours to 94 days). Pain, vomiting and distention were present in almost all of these cases. The most frequent abdominal finding was distention. The location of the volvulus was: ileum, 12 cases (63.2%), root of mesentery, 4 cases (21%) and jejunum, 3 cases (15.8%). Gangrenous bowel was present in six patients (31.5) and gangrenous intestine with perforation in two cases (10.5%) who underwent resection of the involved segment with primary anastomosis. In this group one patient (5.2%) died of sepsis and the wound infection rate was of 37.5%. There was no statistically significant correlation with the duration of illness and the presence of gangrenous loops or the mortality rate (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Pre-Exposure to Ozone Predisposes Oak Leaves to Attacks by Diplodia corticola and Biscogniauxia mediterranea

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    Elena Paoletti

    2007-01-01

    Full Text Available One-year-old cork oak (Quercus suber and turkey oak (Q. cerris seedlings were exposed to ozone (110 ppb, 5 h day˗1, for 30 days and were inoculated with Diplodia corticola and Biscogniauxia mediterranea, respectively, by spraying a suspension of spores on the leaves. Both fungi are endophytic and may act as weak parasites, contributing to oak decline. Ozone exposure stimulated leaf attacks after inoculation, although the physiological, visible, and structural responses of both oaks to O3 exposure were weak. In fact, steady-state gas exchange, leaf waxes, and wettability were not significantly affected by O3. In Q. cerris, O3 altered the structure of stomata, as observed by scanning microscopy, and reduced the leaf relative water content. No hyphal entry through stomata or growth towards stomata was, however, observed. Inoculations were performed in a humid chamber at low light; stomata were likely to be closed. When Q. cerris was inoculated in natural conditions, i.e., in a forest infected by B. mediterranea, seedlings pre-exposed to the enhanced O3 regime had a higher number of B. mediterranea isolates than the controls. This suggests that pre-exposure to O3 predisposed Q. cerris leaves to attacks by B. mediterranea independent of stomata. The hyphae of both fungi were able to enter the leaf through the cuticle, either by gradual in-growth into the cuticle or erosion of a hollow in the cuticle at the point of contact. The primary cause of increased leaf injury in O3-exposed seedlings appeared to be higher germination of spores than on control leaves.

  14. Low Plasma Volume in Normotensive Formerly Preeclamptic Women Predisposes to Hypertension.

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    Scholten, Ralph R; Lotgering, Fred K; Hopman, Maria T; Van Dijk, Arie; Van de Vlugt, Maureen; Janssen, Mirian C H; Spaanderman, Marc E A

    2015-11-01

    Formerly preeclamptic women are at risk for cardiovascular disease. Low plasma volume may reflect latent hypertension and potentially links preeclampsia with chronic cardiovascular disease. We hypothesized that low plasma volume in normotensive formerly preeclamptic women predisposes to hypertension. We longitudinally studied n=104 formerly preeclamptic women in whom plasma volume was measured 3 to 30 months after the preeclamptic pregnancy. Cardiovascular variables were assessed at 2 points in time (3-30 months postpartum and 2-5 years thereafter). Study population was divided into low plasma volume (≤1373 mL/m(2)) and normal plasma volume (>1373 mL/m(2)). Primary end point was hypertension at the second visit: defined as ≥140 mm Hg systolic or ≥90 mm Hg diastolic. Secondary outcome of this study was change in traditional cardiovascular risk profile between visits. Variables correlating univariately with change in blood pressure between visits were introduced in regression analysis. Eighteen of 104 (17%) formerly preeclamptic women who were normotensive at first visit had hypertension at second evaluation 2 to 5 years later. Hypertension developed more often in women with low plasma volume (10/35 [29%]) than in women with normal plasma volume (8/69 [12%]; odds ratio, 3.2; 95% confidence interval, 1.4-8.6). After adjustments, relationship between plasma volume status and subsequent hypertension persisted (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.5). Mean arterial pressure at second visit correlated inverse linearly with plasma volume (r=-0.49; Phypertension within 5 years. Women with low plasma volume have higher chance to develop hypertension than women with normal plasma volume. Clinically, follow-up of blood pressure seems warranted in women with history of preeclampsia, even when initially normotensive.

  15. Targeted deletion of multiple CTCF-binding elements in the human C-MYC gene reveals a requirement for CTCF in C-MYC expression.

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    Wendy M Gombert

    Full Text Available BACKGROUND: Insulators and domain boundaries both shield genes from adjacent enhancers and inhibit intrusion of heterochromatin into transgenes. Previous studies examined the functional mechanism of the MYC insulator element MINE and its CTCF binding sites in the context of transgenes that were randomly inserted into the genome by transfection. However, the contribution of CTCF binding sites to both gene regulation and maintenance of chromatin has not been tested at the endogenous MYC gene. METHODOLOGY/PRINCIPAL FINDINGS: To determine the impact of CTCF binding on MYC expression, a series of mutant human chromosomal alleles was prepared in homologous recombination-efficient DT40 cells and individually transferred by microcell fusion into murine cells. Functional tests reported here reveal that deletion of CTCF binding elements within the MINE does not impact the capacity of this locus to correctly organize an 'accessible' open chromatin domain, suggesting that these sites are not essential for the formation of a competent, transcriptionally active locus. Moreover, deletion of the CTCF site at the MYC P2 promoter reduces transcription but does not affect promoter acetylation or serum-inducible transcription. Importantly, removal of either CTCF site leads to DNA methylation of flanking sequences, thereby contributing to progressive loss of transcriptional activity. CONCLUSIONS: These findings collectively demonstrate that CTCF-binding at the human MYC locus does not repress transcriptional activity but is required for protection from DNA methylation.

  16. Nuclear reprogramming of luminal-like breast cancer cells generates Sox2-overexpressing cancer stem-like cellular states harboring transcriptional activation of the mTOR pathway

    Science.gov (United States)

    Corominas-Faja, Bruna; Cufí, Sílvia; Oliveras-Ferraros, Cristina; Cuyàs, Elisabet; López-Bonet, Eugeni; Lupu, Ruth; Alarcón, Tomás; Vellon, Luciano; Iglesias, Juan Manuel; Leis, Olatz; Martín, Ángel G; Vazquez-Martin, Alejandro; Menendez, Javier A

    2013-01-01

    Energy metabolism plasticity enables stemness programs during the reprogramming of somatic cells to an induced pluripotent stem cell (iPSC) state. This relationship may introduce a new era in the understanding of Warburg’s theory on the metabolic origin of cancer at the level of cancer stem cells (CSCs). Here, we used Yamanaka’s stem cell technology in an attempt to create stable CSC research lines in which to dissect the transcriptional control of mTOR—the master switch of cellular catabolism and anabolism—in CSC-like states. The rare colonies with iPSC-like morphology, obtained following the viral transduction of the Oct4, Sox2, Klf4, and c-Myc (OSKM) stemness factors into MCF-7 luminal-like breast cancer cells (MCF-7/Rep), demonstrated an intermediate state between cancer cells and bona fide iPSCs. MCF-7/Rep cells notably overexpressed SOX2 and stage-specific embryonic antigen (SSEA)-4 proteins; however, other stemness-related markers (OCT4, NANOG, SSEA-1, TRA-1–60, and TRA-1–81) were found at low to moderate levels. The transcriptional analyses of OSKM factors confirmed the strong but unique reactivation of the endogenous Sox2 stemness gene accompanied by the silencing of the exogenous Sox2 transgene in MCF-7/Rep cells. Some but not all MCF-7/Rep cells acquired strong alkaline phosphatase (AP) activity compared with MCF-7 parental cells. SOX2-overexpressing MCF-7/Rep cells contained drastically higher percentages of CD44+ and ALDEFLUOR-stained ALDHbright cells than MCF-7 parental cells. The overlap between differentially expressed mTOR signaling-related genes in 3 different SOX2-overexpressing CSC-like cell lines revealed a notable downregulation of 3 genes, PRKAA1 (which codes for the catalytic α 1 subunit of AMPK), DDIT4/REDD1 (a stress response gene that operates as a negative regulator of mTOR), and DEPTOR (a naturally occurring endogenous inhibitor of mTOR activity). The insulin-receptor gene (INSR) was differentially upregulated in MCF-7/Rep

  17. A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity.

    Science.gov (United States)

    Frayling, Timothy M; Timpson, Nicholas J; Weedon, Michael N; Zeggini, Eleftheria; Freathy, Rachel M; Lindgren, Cecilia M; Perry, John R B; Elliott, Katherine S; Lango, Hana; Rayner, Nigel W; Shields, Beverley; Harries, Lorna W; Barrett, Jeffrey C; Ellard, Sian; Groves, Christopher J; Knight, Bridget; Patch, Ann-Marie; Ness, Andrew R; Ebrahim, Shah; Lawlor, Debbie A; Ring, Susan M; Ben-Shlomo, Yoav; Jarvelin, Marjo-Riitta; Sovio, Ulla; Bennett, Amanda J; Melzer, David; Ferrucci, Luigi; Loos, Ruth J F; Barroso, Inês; Wareham, Nicholas J; Karpe, Fredrik; Owen, Katharine R; Cardon, Lon R; Walker, Mark; Hitman, Graham A; Palmer, Colin N A; Doney, Alex S F; Morris, Andrew D; Smith, George Davey; Hattersley, Andrew T; McCarthy, Mark I

    2007-05-11

    Obesity is a serious international health problem that increases the risk of several common diseases. The genetic factors predisposing to obesity are poorly understood. A genome-wide search for type 2 diabetes-susceptibility genes identified a common variant in the FTO (fat mass and obesity associated) gene that predisposes to diabetes through an effect on body mass index (BMI). An additive association of the variant with BMI was replicated in 13 cohorts with 38,759 participants. The 16% of adults who are homozygous for the risk allele weighed about 3 kilograms more and had 1.67-fold increased odds of obesity when compared with those not inheriting a risk allele. This association was observed from age 7 years upward and reflects a specific increase in fat mass.

  18. Overexpressed TP73 induces apoptosis in medulloblastoma

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    Perlaky Laszlo

    2007-07-01

    Full Text Available Abstract Background Medulloblastoma is the most common malignant brain tumor of childhood. Children who relapse usually die of their disease, which reflects resistance to radiation and/or chemotherapy. Improvements in outcome require a better understanding of the molecular basis of medulloblastoma growth and treatment response. TP73 is a member of the TP53 tumor suppressor gene family that has been found to be overexpressed in a variety of tumors and mediates apoptotic responses to genotoxic stress. In this study, we assessed expression of TP73 RNA species in patient tumor specimens and in medulloblastoma cell lines, and manipulated expression of full-length TAp73 and amino-terminal truncated ΔNp73 to assess their effects on growth. Methods We analyzed medulloblastoma samples from thirty-four pediatric patients and the established medulloblastoma cell lines, Daoy and D283MED, for expression of TP73 RNA including the full-length transcript and the 5'-terminal variants that encode the ΔNp73 isoform, as well as TP53 RNA using quantitative real time-RTPCR. Protein expression of TAp73 and ΔNp73 was quantitated with immunoblotting methods. Clinical outcome was analyzed based on TP73 RNA and p53 protein expression. To determine effects of overexpression or knock-down of TAp73 and ΔNp73 on cell cycle and apoptosis, we analyzed transiently transfected medulloblastoma cell lines with flow cytometric and TUNEL methods. Results Patient medulloblastoma samples and cell lines expressed full-length and 5'-terminal variant TP73 RNA species in 100-fold excess compared to non-neoplastic brain controls. Western immunoblot analysis confirmed their elevated levels of TAp73 and amino-terminal truncated ΔNp73 proteins. Kaplan-Meier analysis revealed trends toward favorable overall and progression-free survival of patients whose tumors display TAp73 RNA overexpression. Overexpression of TAp73 or ΔNp73 induced apoptosis under basal growth conditions in vitro and

  19. Overexpression of PDGFRA cooperates with loss of NF1 and p53 to accelerate the molecular pathogenesis of malignant peripheral nerve sheath tumors.

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    Ki, D H; He, S; Rodig, S; Look, A T

    2017-02-23

    Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, frequently metastatic sarcomas that are associated with neurofibromatosis type 1 (NF1), a prominent inherited genetic disease in humans. Although loss of the NF1 gene predisposes to MPNST induction, relatively long tumor latency in NF1 patients suggests that additional genetic or epigenetic abnormalities are needed for the development of these nerve sheath malignancies. To study the molecular pathways contributing to the formation of MPNSTs in NF1 patients, we used a zebrafish tumor model defined by nf1 loss in a p53-deficient background together with the overexpression of either wild-type or constitutively activated PDGFRA (platelet-derived growth factor receptor-α) under control of the sox10 neural crest-specific promoter. Here we demonstrate the accelerated onset and increased penetrance of MPNST formation in fish overexpressing both the wild-type and the mutant PDGFRA transgenes in cells of neural crest origin. Interestingly, overexpression of the wild-type PDGFRA was even more potent in promoting transformation than the mutant PDGFRA, which is important because ~78% of human MPNSTs have expression of wild-type PDGFRA, whereas only 5% harbor activating mutations of the gene encoding this receptor. Further analysis revealed the induction of cellular senescence in zebrafish embryos overexpressing mutant, but not wild-type, PDGFRA, suggesting a mechanism through which the oncogenic activity of the mutant receptor is tempered by the activation of premature cellular senescence in an NF1-deficient background. Taken together, our study suggests a model in which overexpression of wild-type PDGFRA associated with NF1 deficiency leads to aberrant activation of downstream RAS signaling and thus contributes importantly to MPNST development-a prediction supported by the ability of the kinase inhibitor sunitinib alone and in combination with the MEK inhibitor trametinib to retard MPNST progression in

  20. Overexpression of PDGFRA cooperates with loss of NF1 and p53 to accelerate the molecular pathogenesis of malignant peripheral nerve sheath tumors

    Science.gov (United States)

    Ki, D H; He, S; Rodig, S; Look, A T

    2017-01-01

    Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, frequently metastatic sarcomas that are associated with neurofibromatosis type 1 (NF1), a prominent inherited genetic disease in humans. Although loss of the NF1 gene predisposes to MPNST induction, relatively long tumor latency in NF1 patients suggests that additional genetic or epigenetic abnormalities are needed for the development of these nerve sheath malignancies. To study the molecular pathways contributing to the formation of MPNSTs in NF1 patients, we used a zebrafish tumor model defined by nf1 loss in a p53-deficient background together with the overexpression of either wild-type or constitutively activated PDGFRA (platelet-derived growth factor receptor-α) under control of the sox10 neural crest-specific promoter. Here we demonstrate the accelerated onset and increased penetrance of MPNST formation in fish overexpressing both the wild-type and the mutant PDGFRA transgenes in cells of neural crest origin. Interestingly, overexpression of the wild-type PDGFRA was even more potent in promoting transformation than the mutant PDGFRA, which is important because ~78% of human MPNSTs have expression of wild-type PDGFRA, whereas only 5% harbor activating mutations of the gene encoding this receptor. Further analysis revealed the induction of cellular senescence in zebrafish embryos overexpressing mutant, but not wild-type, PDGFRA, suggesting a mechanism through which the oncogenic activity of the mutant receptor is tempered by the activation of premature cellular senescence in an NF1-deficient background. Taken together, our study suggests a model in which overexpression of wild-type PDGFRA associated with NF1 deficiency leads to aberrant activation of downstream RAS signaling and thus contributes importantly to MPNST development—a prediction supported by the ability of the kinase inhibitor sunitinib alone and in combination with the MEK inhibitor trametinib to retard MPNST progression in

  1. Abnormal ulnar nerve anatomy in the distal forearm pre-disposes to post-traumatic ulnar neuritis at the wrist.

    Science.gov (United States)

    Yeo, C J; Little, C P; Deshmukh, S C

    2005-01-01

    Anatomical variations of the ulnar nerve have been described at the level of the elbow and in Guyon's canal, while the path in the forearm has always been assumed to be constant. We present a case of compressive ulnar neuropathy at the wrist pre-disposed by a presumed congenital variation of the path of the ulnar nerve at the level of the wrist which improved following surgical release of the constriction caused as a result of it.

  2. A Case of Candida albicans Endophthalmitis with No Predisposing Risk Factors and a Distant Source of Infection

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    Randhir Chavan

    2012-09-01

    Full Text Available Purpose: To report a case of Candida albicans endophthalmitis with no identifiable predisposing risk factors. Case Report: A 57-year-old male presented with a 3-day history of worsening floaters and reduced visual acuity. Fundoscopy and optical coherence tomography showed presence of fluffy white preretinal and intraretinal infiltrates. With no past medical history or evidence of immunosuppression but having travelled abroad and suffered from diarrhoea, fungal aetiology was thought to be unlikely and as a result, treatment was commenced for toxoplasma. Despite treatment, his vision did not improve. Initial investigations including inflammatory markers, serology for toxoplasmosis, blood culture, chest radiograph and aqueous sampling could not identify a source of infection. However, polymerase chain reaction results from vitreous sampling revealed C. albicans. As a result, the patient was treated with intravenous voriconazole and intravitreal amphotericin B. As initial clinical improvement was limited, a vitrectomy was performed with further intravitreal amphotericin B. Clinical improvement was rapid following vitrectomy. After repeated Gram staining and culture of infected toenails, Gram-positive yeast cells were isolated. Conclusion: Although C. albicans is a frequent cause of endogenous endophthalmitis, patients often have one or more predisposing systemic condition assisting the diagnosis. The present case illustrates that (1 even in the absence of any predisposing risk factors, C.albicans should be considered as a possible differential diagnosis in recalcitrant uveitis, and (2 endogenous candida endophthalmitis can be a result of fungal infections from distant sites such as the toenails.

  3. Nucleophosmin is overexpressed in thyroid tumors

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    Pianta, Annalisa; Puppin, Cinzia [Dipartimento di Scienze e Tecnologie Biomediche, Universita di Udine, Udine (Italy); Franzoni, Alessandra; Fabbro, Dora [Azienda Ospedaliero-Universitaria ' S. Maria della Misericordia' Udine, Udine (Italy); Di Loreto, Carla [Dipartimento di Ricerche Mediche e Morfologiche, Universita di Udine, Udine (Italy); Bulotta, Stefania [Department of Pharmacobiological Sciences, Universita di Catanzaro ' Magna Graecia' , Catanzaro (Italy); Deganuto, Marta; Paron, Igor; Tell, Gianluca [Dipartimento di Scienze e Tecnologie Biomediche, Universita di Udine, Udine (Italy); Puxeddu, Efisio [Department of Internal Medicine, Universita di Perugia, Perugia (Italy); Filetti, Sebastiano [Department of Clinical Sciences, Universita di Roma ' La Sapienza' , Roma (Italy); Russo, Diego [Department of Pharmacobiological Sciences, Universita di Catanzaro ' Magna Graecia' , Catanzaro (Italy); Damante, Giuseppe, E-mail: giuseppe.damante@uniud.it [Dipartimento di Scienze e Tecnologie Biomediche, Universita di Udine, Udine (Italy); Azienda Ospedaliero-Universitaria ' S. Maria della Misericordia' Udine, Udine (Italy)

    2010-07-02

    Nucleophosmin (NPM) is a protein that contributes to several cell functions. Depending on the context, it can act as an oncogene or tumor suppressor. No data are available on NPM expression in thyroid cells. In this work, we analyzed both NPM mRNA and protein levels in a series of human thyroid tumor tissues and cell lines. By using immunohistochemistry, NPM overexpression was detected in papillary, follicular, undifferentiated thyroid cancer, and also in follicular benign adenomas, indicating it as an early event during thyroid tumorigenesis. In contrast, various levels of NPM mRNA levels as detected by quantitative RT-PCR were observed in tumor tissues, suggesting a dissociation between protein and transcript expression. The same behavior was observed in the normal thyroid FRTL5 cell lines. In these cells, a positive correlation between NPM protein levels, but not mRNA, and proliferation state was detected. By using thyroid tumor cell lines, we demonstrated that such a post-mRNA regulation may depend on NPM binding to p-Akt, whose levels were found to be increased in the tumor cells, in parallel with reduction of PTEN. In conclusion, our present data demonstrate for the first time that nucleophosmin is overexpressed in thyroid tumors, as an early event of thyroid tumorigenesis. It seems as a result of a dysregulation occurring at protein and not transcriptional level related to an increase of p-Akt levels of transformed thyrocytes.

  4. Overexpression of Id1 in transgenic mice promotes mammary basal stem cell activity and breast tumorigenesis.

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    Shin, Dong-Hui; Park, Ji-Hye; Lee, Jeong-Yeon; Won, Hee-Young; Jang, Ki-Seok; Min, Kyueng-Whan; Jang, Si-Hyong; Woo, Jong-Kyu; Oh, Seung Hyun; Kong, Gu

    2015-07-10

    Inhibitor of differentiation/DNA binding (Id)1 is a crucial regulator of mammary development and breast cancer progression. However, its effect on stemness and tumorigenesis in mammary epithelial cells remains undefined. Herein, we demonstrate that Id1 induces mammary tumorigenesis by increasing normal and malignant mammary stem cell (MaSC) activities in transgenic mice. MaSC-enriched basal cell expansion and increased self-renewal and in vivo regenerative capacity of MaSCs are observed in the mammary glands of MMTV-Id1 transgenic mice. Furthermore, MMTV-Id1 mice develop ductal hyperplasia and mammary tumors with highly expressed basal markers. Id1 also increases breast cancer stem cell (CSC) population and activity in human breast cancer lines. Moreover, the effects of Id1 on normal and malignant stem cell activities are mediated by the Wnt/c-Myc pathway. Collectively, these findings provide in vivo genetic evidence of Id1 functions as an oncogene in breast cancer and indicate that Id1 regulates mammary basal stem cells by activating the Wnt/c-Myc pathway, thereby contributing to breast tumor development.

  5. Diet-Induced Obesity in Mice Overexpressing Neuropeptide Y in Noradrenergic Neurons

    Directory of Open Access Journals (Sweden)

    Suvi T. Ruohonen

    2012-01-01

    Full Text Available Neuropeptide Y (NPY is a neurotransmitter associated with feeding and obesity. We have constructed an NPY transgenic mouse model (OE- mouse, where targeted overexpression leads to increased levels of NPY in noradrenergic and adrenergic neurons. We previously showed that these mice become obese on a normal chow. Now we aimed to study the effect of a Western-type diet in OE- and wildtype (WT mice, and to compare the genotype differences in the development of obesity, insulin resistance, and diabetes. Weight gain, glucose, and insulin tolerance tests, fasted plasma insulin, and cholesterol levels were assayed. We found that female OE- mice gained significantly more weight without hyperphagia or decreased activity, and showed larger white and brown fat depots with no difference in UCP-1 levels. They also displayed impaired glucose tolerance and decreased insulin sensitivity. OE- and WT males gained weight robustly, but no difference in the degree of adiposity was observed. However, 40% of but none of the WT males developed hyperglycaemia while on the diet. The present study shows that female OE- mice were not protected from the obesogenic effect of the diet suggesting that increased NPY release may predispose females to a greater risk of weight gain under high caloric conditions.

  6. Catalase overexpression in aortic smooth muscle prevents pathological mechanical changes underlying abdominal aortic aneurysm formation.

    Science.gov (United States)

    Maiellaro-Rafferty, Kathryn; Weiss, Daiana; Joseph, Giji; Wan, William; Gleason, Rudolph L; Taylor, W Robert

    2011-08-01

    The causality of the associations between cellular and mechanical mechanisms of abdominal aortic aneurysm (AAA) formation has not been completely defined. Because reactive oxygen species are established mediators of AAA growth and remodeling, our objective was to investigate oxidative stress-induced alterations in aortic biomechanics and microstructure during subclinical AAA development. We investigated the mechanisms of AAA in an angiotensin II (ANG II) infusion model of AAA in apolipoprotein E-deficient (apoE(-/-)) mice that overexpress catalase in vascular smooth muscle cells (apoE(-/-)xTg(SMC-Cat)). At baseline, aortas from apoE(-/-)xTg(SMC-Cat) exhibited increased stiffness and the microstructure was characterized by 50% more collagen content and less elastin fragmentation. ANG II treatment for 7 days in apoE(-/-) mice altered the transmural distribution of suprarenal aortic circumferential strain (quantified by opening angle, which increased from 130 ± 1° at baseline to 198 ± 8° after 7 days of ANG II treatment) without obvious changes in the aortic microstructure. No differences in aortic mechanical behavior or suprarenal opening angle were observed in apoE(-/-)xTg(SMC-Cat) after 7 days of ANG II treatment. These data suggest that at the earliest stages of AAA development H(2)O(2) is functionally important and is involved in the control of local variations in remodeling across the vessel wall. They further suggest that reduced elastin integrity at baseline may predispose the abdominal aorta to aneurysmal mechanical remodeling.

  7. Targeted anticancer therapy: overexpressed receptors and nanotechnology.

    Science.gov (United States)

    Akhtar, Mohd Javed; Ahamed, Maqusood; Alhadlaq, Hisham A; Alrokayan, Salman A; Kumar, Sudhir

    2014-09-25

    Targeted delivery of anticancer drugs to cancer cells and tissues is a promising field due to its potential to spare unaffected cells and tissues, but it has been a major challenge to achieve success in these therapeutic approaches. Several innovative approaches to targeted drug delivery have been devised based on available knowledge in cancer biology and on technological advancements. To achieve the desired selectivity of drug delivery, nanotechnology has enabled researchers to design nanoparticles (NPs) to incorporate anticancer drugs and act as nanocarriers. Recently, many receptor molecules known to be overexpressed in cancer have been explored as docking sites for the targeting of anticancer drugs. In principle, anticancer drugs can be concentrated specifically in cancer cells and tissues by conjugating drug-containing nanocarriers with ligands against these receptors. Several mechanisms can be employed to induce triggered drug release in response to either endogenous trigger or exogenous trigger so that the anticancer drug is only released upon reaching and preferentially accumulating in the tumor tissue. This review focuses on overexpressed receptors exploited in targeting drugs to cancerous tissues and the tumor microenvironment. We briefly evaluate the structure and function of these receptor molecules, emphasizing the elegant mechanisms by which certain characteristics of cancer can be exploited in cancer treatment. After this discussion of receptors, we review their respective ligands and then the anticancer drugs delivered by nanotechnology in preclinical models of cancer. Ligand-functionalized nanocarriers have delivered significantly higher amounts of anticancer drugs in many in vitro and in vivo models of cancer compared to cancer models lacking such receptors or drug carrying nanocarriers devoid of ligand. This increased concentration of anticancer drug in the tumor site enabled by nanotechnology could have a major impact on the efficiency of cancer

  8. Overexpression of Colligin 2 in Glioma Vasculature is Associated with Overexpression of Heat Shock Factor 2.

    Science.gov (United States)

    Mustafa, Dana A M; Sieuwerts, Anieta M; Zheng, Ping Pin; Kros, Johan M

    2010-10-20

    In previous studies we found expression of the protein colligin 2 (heat shock protein 47 (HSP47), SERPINH1) in glioma neovasculature while not in normal brain tissue. Generally, the regulation of heat shock gene expression in eukaryotes is mediated by heat shock factors (HSF). In mammals, three heat shock transcription factors, HSF-1, -2, and -4, have been isolated. Here we investigated the relation between the expression of colligin 2 and these heat shock factors at the mRNA level using real-time reverse transcriptase PCR (qRT-PCR) in different grades of astrocytic tumorigenesis, viz., low-grade glioma and glioblastoma. Endometrium samples, representing physiological angiogenesis, were included as controls. Since colligin 2 is a chaperon for collagens, the gene expression of collagen I (COL1A1) was also investigated. The blood vessel density of the samples was monitored by expression of the endothelial marker CD31 (PECAM1). Because NG2-immunopositive pericytic cells are involved in glioma neovascularization, the expression of NG2 (CSPG4) was also measured.We demonstrate overexpression of HSF2 in both stages of glial tumorigenesis (reaching significance only in low-grade glioma) and also minor elevated levels of HSF1 as compared to normal brain. There were no differences in expression of HSF4 between low-grade glioma and normal brain while HSF4 was downregulated in glioblastoma. In the endometrium samples, none of the HSFs were upregulated. In the low-grade gliomas SERPINH appeared to be slightly overexpressed with a parallel 4-fold upregulation of COL1A1, while in glioblastoma there was over 5-fold overexpression of SERPINH1 and more than 150-fold overexpression of COL1A1. In both the lowgrade gliomas and the glioblastomas overexpression of CSPG4 was found and overexpression of PECAM1 was only found in the latter. Our data suggest that the upregulated expression of colligin 2 in glioma is accompanied by upregulation of COL1A1, CSPG4, HSF2 and to a lesser extent

  9. Two necrotic enteritis predisposing factors, dietary fishmeal and Eimeria infection, induce large changes in the caecal microbiota of broiler chickens.

    Science.gov (United States)

    Wu, Shu-Biao; Stanley, Dragana; Rodgers, Nicholas; Swick, Robert A; Moore, Robert J

    2014-03-14

    It is widely established that a high-protein fishmeal supplemented starter diet and Eimeria infection can predispose birds to the development of clinical necrotic enteritis symptoms following Clostridium perfringens infection. However, it has not been clearly established what changes these treatments cause to predispose birds to succumb to necrotic enteritis. We analysed caecal microbiota of 4 groups of broilers (n=12) using deep pyrosequencing of 16S rDNA amplicons: (1) control chicks fed a control diet, (2) Eimeria infected chicks fed control diet, (3) chicks fed fishmeal supplemented diet and lastly (4) both fishmeal fed and Eimeria infected chicks. We found that the high-protein fishmeal diet had a strong effect on the intestinal microbiota similar to the previously reported effect of C. perfringens infection. We noted major changes in the prevalence of various lactobacilli while the total culturable Lactobacillus counts remained stable. The Ruminococcaceae, Lachnospiraceae, unknown Clostridiales and Lactobacillaceae families were most affected by fishmeal with increases in a number of operational taxonomic units (OTUs) that had previously been linked to Crohn's disease and reductions in OTUs known to be butyrate producers. Eimeria induced very different changes in microbiota; Ruminococcaceae groups were reduced in number and three unknown Clostridium species were increased in abundance. Additionally, Eimeria did not significantly influence changes in pH, formic, propionic or isobutyric acid while fishmeal induced dramatic changes in all these measures. Both fishmeal feeding and Eimeria infection induced significant changes in the gut microbiota; these changes may play an important role in predisposing birds to necrotic enteritis.

  10. Absence of the predisposing factors and signs and symptoms usually associated with overreaching and overtraining in physical fitness centers

    Directory of Open Access Journals (Sweden)

    Carolina Ackel-D'Elia

    2010-01-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the occurrence of the well-known predisposing factors and signs and symptoms usually associated with either overreaching or overtraining syndrome in physical fitness centers in São Paulo City, Brazil. METHOD: A questionnaire consisting of 13 question groups pertaining to either predisposing factors (1-7 or signs and symptoms (8-13 was given to 413 subjects. The general training schedule of the volunteers was characterized by workout sessions of 2.18 ± 0.04 h for a total of 11.0 ± 0.3 h/week for 33 ± 2 months independent of the type of exercise performed (walking, running, spinning, bodybuilding and stretching. A mean score was calculated ranging from 1 (completely absent to 5 (severe for each question group. A low occurrence was considered to be a question group score lower than 4, which was observed in all 13 question groups. RESULTS: The psychological evaluation by POMS Mood State Questionnaire indicated a normal non-inverted iceberg. The hematological parameters, creatine kinase activity, cortisol, total testosterone and free testosterone concentrations were within the normal ranges for the majority of the volunteers selected for this analysis (n = 60. CONCLUSION: According to the questionnaire score analysis, no predisposing factors or signs and symptoms usually associated with either overreaching or overtraining were detected among the members of physical fitness centers in São Paulo City, Brazil. This observation was corroborated by the absence of any significant hematological or stress hormone level alterations in blood analyses of the majority of the selected volunteers (n = 60.

  11. Recurrent microdeletions at 15q11.2 and 16p13.11 predispose to idiopathic generalized epilepsies

    DEFF Research Database (Denmark)

    de Kovel, Carolien G F; Trucks, Holger; Helbig, Ingo;

    2010-01-01

    Idiopathic generalized epilepsies account for 30% of all epilepsies. Despite a predominant genetic aetiology, the genetic factors predisposing to idiopathic generalized epilepsies remain elusive. Studies of structural genomic variations have revealed a significant excess of recurrent microdeletions...... at 1q21.1, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 in various neuropsychiatric disorders including autism, intellectual disability and schizophrenia. Microdeletions at 15q13.3 have recently been shown to constitute a strong genetic risk factor for common idiopathic generalized epilepsy...

  12. Predisposing factors and histopathological variants of cutaneous squamous cell carcinoma: Experience from a North Indian teaching hospital

    Directory of Open Access Journals (Sweden)

    Geeti Khullar

    2016-01-01

    Full Text Available Background: Squamous and basal cell carcinomas together constitute the majority of non-melanoma skin cancers. These malignancies are infrequent in Indians as compared to the white skinned population. Literature on squamous cell carcinoma in dark skin is limited. Aim: To analyze the risk factors and to characterize the histopathological subtypes of cutaneous squamous cell carcinoma in Indian patients in an area, non-endemic for arsenicosis. Methods: A retrospective analysis of data from January 2003 to August 2013 was performed to evaluate the predisposing factors and histopathological types of cutaneous squamous cell carcinoma at the Postgraduate Institute of Medical Education and Research (PGIMER, Chandigarh. Demographic and disease characteristics such as age, gender and predisposing factors, particularly premalignant dermatoses were recorded and histopathology slides were reviewed. Results: Of the 13,426 skin biopsy specimens received during the 10-year period, there were 82 (0.6% cases of squamous cell carcinoma and 170 (1.7% of basal cell carcinoma. The mean age at diagnosis of cutaneous squamous cell carcinoma was 53.7 years and the male to female ratio was 2:1. The most common site of involvement was the lower limbs in 34 (41.5% patients. Marjolin's ulcer was present in 36 (43.9% cases. No predisposing factor was identified in 35 (42.7% patients. Histopathologically, the tumors were classified most commonly as squamous cell carcinoma not otherwise specified in 33 (40.2% cases. Limitations: This was a retrospective study and details of occupation and interval between the precursor lesions and development of tumor were not recorded. Immunohistochemistry for human papilloma virus and p53 tumor suppressor protein were not performed as these tests were not available. Conclusion: Cutaneous squamous cell carcinoma is uncommon in Indian patients and a high index of suspicion is necessary when a rapidly enlarging nodule, verrucous fungating plaque

  13. Characterization of a naturally-occurring p27 mutation predisposing to multiple endocrine tumors

    Directory of Open Access Journals (Sweden)

    Pulz Elke

    2010-05-01

    Full Text Available Abstract Background p27Kip1 (p27 is an important negative regulator of the cell cycle and a putative tumor suppressor. The finding that a spontaneous germline frameshift mutation in Cdkn1b (encoding p27 causes the MENX multiple endocrine neoplasia syndrome in the rat provided the first evidence that Cdkn1b is a tumor susceptibility gene for endocrine tumors. Noteworthy, germline p27 mutations were also identified in human patients presenting with endocrine tumors. At present, it is not clear which features of p27 are crucial for this tissue-specific tumor predisposition in both rats and humans. It was shown that the MENX-associated Cdkn1b mutation causes reduced expression of the encoded protein, but the molecular mechanisms are unknown. To better understand the role of p27 in tumor predisposition and to characterize the MENX animal model at the molecular level, a prerequisite for future preclinical studies, we set out to assess the functional properties of the MENX-associated p27 mutant protein (named p27fs177 in vitro and in vivo. Results In vitro, p27fs177 retains some properties of the wild-type p27 (p27wt protein: it localizes to the nucleus; it interacts with cyclin-dependent kinases and, to lower extent, with cyclins. In contrast to p27wt, p27fs177 is highly unstable and rapidly degraded in every phase of the cell-cycle, including quiescence. It is in part degraded by Skp2-dependent proteasomal proteolysis, similarly to p27wt. Photobleaching studies showed reduced motility of p27fs177 in the nucleus compared to p27wt, suggesting that in this compartment p27fs177 is part of a multi-protein complex, likely together with the degradation machinery. Studies of primary rat newborn fibroblasts (RNF established from normal and MENX-affected littermates confirmed the rapid degradation of p27fs177 in vivo which can be rescued by Bortezomib (proteasome inhibitor drug. Overexpression of the negative regulators microRNA-221/222 plays no role in

  14. Somatic inactivation of ATM in hematopoietic cells predisposes mice to cyclin D3 dependent T cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Ehrlich, Lori A; Yang-Iott, Katherine; DeMicco, Amy; Bassing, Craig H

    2015-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) is a cancer of immature T cells that exhibits heterogeneity of oncogenic lesions, providing an obstacle for development of more effective and less toxic therapies. Inherited deficiency of ATM, a regulator of the cellular DNA damage response, predisposes young humans and mice to T-ALLs with clonal chromosome translocations. While acquired ATM mutation or deletion occurs in pediatric T-ALLs, the role of somatic ATM alterations in T-ALL pathogenesis remains unknown. We demonstrate here that somatic Atm inactivation in haematopoietic cells starting as these cells differentiate in utero predisposes mice to T-ALL at similar young ages and harboring analogous translocations as germline Atm-deficient mice. However, some T-ALLs from haematopoietic cell specific deletion of Atm were of more mature thymocytes, revealing that the developmental timing and celluar origin of Atm inactivation influences the phenotype of ATM-deficient T-ALLs. Although it has been hypothesized that ATM suppresses cancer by preventing deletion and inactivation of TP53, we find that Atm inhibits T-ALL independent of Tp53 deletion. Finally, we demonstrate that the Cyclin D3 protein that drives immature T cell proliferation is essential for transformation of Atm-deficient thymocytes. Our study establishes a pre-clinical model for pediatric T-ALLs with acquired ATM inactivation and identifies the cell cycle machinery as a therapeutic target for this aggressive childhood T-ALL subtype.

  15. [Candida carriage in the oral mucosa of a student population: adhesiveness of the strains and predisposing factors].

    Science.gov (United States)

    Negroni, M; González, M I; Levin, B; Cuesta, A; Iovanniti, C

    2002-01-01

    The aim of this study was to establish oral carriage of Candida and possible factors associated to their virulence in young adults and their relation with local and general situations considered as predisposing factors. Samples were obtained from dorsum tongue in 70 students attending the Faculty of Dentistry (University of Buenos Aires) average age: 23, all in healthy oral conditions. Of these, 21.42% were Candida positive. These samples were seeded in CHROMagar. Candida identification was completed in milk agar and Fungichrom 1. The following species were identified: 11 Candida albicans (C.a), 2 Candida parapsilosis (C.p) and 1 Candida glabrata (C.g). In one case, 2 species (C.a and C.g) were isolated in the same sample. Virulence was determined as adherence capacity by biofilm or in vitro plaque formation and hydrophobicity. Different host factors were analyzed statistically to establish their importance as predisposing factors to allow Candida colonization. Adherence of C.a. was found to be similar in all C.a. strains, whereas significant differences were found between C.a. and C.p. and between C.a. and C.g. Only the antiseptic mouthrinse and the diet were significant among the considered factors.

  16. Pokemon,c-myc and breast tumor%Pokemon、c-myc与乳腺肿瘤

    Institute of Scientific and Technical Information of China (English)

    付朝江; 崔明

    2009-01-01

    Pokemon(POK erythroid ontogenic factor)蛋白,即POK红系髓性致癌因子,是POK转录抑制物家族的一个成员,为ZBTB7基因所编码的产物.Pokemon蛋白作为转录因子参与一些细胞基因转录的调节,并在细胞分化过程中发挥着关键、多效性的功能.近来发现,Pokemon和c-myc在乳腺肿瘤致癌转化过程中发挥着至关重要的作用,并与乳腺肿瘤的发生密切相关.c-myc原癌基因编码核内DNA结合蛋白,调节其它基因的转录.其基因、mRNA及编码蛋白在多种肿瘤组织中均有异常.c-myc蛋白主要是通过促进cychnE/CDK2复合物的活性来调控G1期细胞进程的.

  17. Effects of c-Myc and TGF-Alpha on Polarized Membrane Traffic

    Science.gov (United States)

    1999-10-01

    accidental cell death due to excessive ion depletion or accumulation after loss of cell polarity. Interestingly, the CFTR chloride channel, while apical...J. Benos, and R. A. Frizzell. 1994. Polarization-dependent apical membrane CFTR targeting underlies cAMP- stimulated Cl- secretion in epithelial cells

  18. Treatment of Endocrine-Resistant Breast Cancer with a Small Molecule c-Myc Inhibitor

    Science.gov (United States)

    2015-06-01

    Medicine). 2. Based on part of the work supported by this award, last year I have submitted a DoD BCRP Breakthrough Award application entitled: ‘Targeting...Osborne CK, Schiff R, O’Malley BW. 2014. An epigenomic approach to therapy for tamoxifen-resistant breast cancer. Cell Res. 24(7): 809-19. PMID...Our work has established a novel therapeutic strategy to treat ER-positive breast cancer. Based on our study, it has been proposed that BET protein

  19. c-Myc-dependent formation of robertsonian translocation chromosomes in mouse cells

    OpenAIRE

    Amanda Guffei; Zelda Lichtensztejn; Amanda Gonçlves {ptdos} Santos Silva; Louis, Sherif F; Andrea Caporali; Sabine Mai

    2007-01-01

    Robertsonian (Rb) translocation chromosomes occur in human and murine cancers and involve the aberrant joining of two acrocentric chromosomes in humans and two telocentric chromosomes in mice. Mechanisms leading to their generation remain elusive, but models for their formation have been proposed. They include breakage of centromeric sequences and their subsequent fusions, centric misdivision, misparing between highly repetitive sequences of p- tel or p- arm repeats, and recombinational joini...

  20. c-Myc-Dependent Formation of Robertsonian Translocation Chromosomes in Mouse Cells12

    OpenAIRE

    Guffei, Amanda; Lichtensztejn, Zelda; Gonçalves dos Santos Silva, Amanda; Louis, Sherif F; Caporali, Andrea; Mai, Sabine

    2007-01-01

    Robertsonian (Rb) translocation chromosomes occur in human and murine cancers and involve the aberrant joining of two acrocentric chromosomes in humans and two telocentric chromosomes in mice. Mechanisms leading to their generation remain elusive, but models for their formation have been proposed. They include breakage of centromeric sequences and their subsequent fusions, centric misdivision, misparing between highly repetitive sequences of p-tel or p-arm repeats, and recombinational joining...

  1. Treatment of Multiple Myeloma with VLA4-targeted Nanoparticles Delivering Novel c-MYC Inhibitor Prodrug

    Science.gov (United States)

    2012-09-01

    well to chemotherapy and remissions occur in that majority of MM patients, but all patients eventually relapse and die from progressive disease within...6 years. If the residual post- remission cells of their activation to progressive disease could be disrupted with novel targeted therapies. It would...Bagnasco, L., Malacarne, D., Melchiori, A., Valente, P., Millo, E., Bruno, S., Basso, S., and Parodi, S. A retro-inverso peptide homologous to

  2. Need, Enabling, Predisposing, and Behavioral Determinants of Access to Preventative Care in Argentina: Analysis of the National Survey of Risk Factors

    Science.gov (United States)

    Jahangir, Eiman; Irazola, Vilma; Rubinstein, Adolfo

    2012-01-01

    Introduction Health care utilization is an important step to disease management, providing opportunities for prevention and treatment. Anderson’s Health Behavior Model has defined utilization by need, predisposing, and enabling determinants. We hypothesize that need, predisposing, and enabling, highlighting behavioral factors are associated with utilization in Argentina. Methods We performed a logistic regression analysis of the 2005 and 2009 Argentinean Survey of Risk Factors, a cohort of 41,392 and 34,732 individuals, to explore the association between need, enabling, predisposing, and behavioral factors to blood pressure measurement in the last year. Results In the 2005 cohort, blood pressure measurement was associated with perception of health, insurance coverage, basic needs met, and income. Additionally, female sex, civil state, household type, older age groups, education, and alcohol use were associated with utilization. The 2009 cohort showed similar associations with only minor differences between the models. Conclusions We explored the association between utilization of clinical preventive services with need, enabling, predisposing, and behavioral factors. While predisposing and need determinants are associated with utilization, enabling factors such as insurance coverage provides an area for public intervention. These are important findings where policies should be focused to improve utilization of preventive services in Argentina. PMID:22984608

  3. Therapeutics Targeting Drivers of Thoracic Aortic Aneurysms and Acute Aortic Dissections: Insights from Predisposing Genes and Mouse Models.

    Science.gov (United States)

    Milewicz, Dianna M; Prakash, Siddharth K; Ramirez, Francesco

    2017-01-14

    Thoracic aortic diseases, including aneurysms and dissections of the thoracic aorta, are a major cause of morbidity and mortality. Risk factors for thoracic aortic disease include increased hemodynamic forces on the ascending aorta, typically due to poorly controlled hypertension, and heritable genetic variants. The altered genes predisposing to thoracic aortic disease either disrupt smooth muscle cell (SMC) contraction or adherence to an impaired extracellular matrix, or decrease canonical transforming growth factor beta (TGF-β) signaling. Paradoxically, TGF-β hyperactivity has been postulated to be the primary driver for the disease. More recently, it has been proposed that the response of aortic SMCs to the hemodynamic load on a structurally defective aorta is the primary driver of thoracic aortic disease, and that TGF-β overactivity in diseased aortas is a secondary, unproductive response to restore tissue function. The engineering of mouse models of inherited aortopathies has identified potential therapeutic agents to prevent thoracic aortic disease.

  4. Frequency of 3' VNTR Polymorphism in the Dopamine Transporter Gene SLC6A3 in Humans Predisposed to Antisocial Behavior.

    Science.gov (United States)

    Cherepkova, E V; Aftanas, L I; Maksimov, N; Menshanov, P N

    2016-11-01

    Predisposition to antisocial behavior can be related to the presence of certain polymorphic variants of genes encoding dopaminergic system proteins. We studied the frequencies of allele variants and genotypes of variable number tandem repeat polymorphism in 3' untranslated region (3' VTNR) of the dopaminergic transporter SLC6A3 gene in Caucasian men committed socially dangerous violent and non-violent crimes. Alleles with 9 and 10 repeats were most frequent in both the control group and group of men predisposed to antisocial behavior. At the same time, the 10/10 genotype was more frequently observed in the group of men prone to antisocial non-violent behavior. Hence, the presence of certain variants of 3' VTNR polymorphism of SLC6A3 gene in men is associated with predisposition to certain forms of antisocial behavior.

  5. The mycotoxin deoxynivalenol predisposes for the development of Clostridium perfringens-induced necrotic enteritis in broiler chickens.

    Science.gov (United States)

    Antonissen, Gunther; Van Immerseel, Filip; Pasmans, Frank; Ducatelle, Richard; Haesebrouck, Freddy; Timbermont, Leen; Verlinden, Marc; Janssens, Geert Paul Jules; Eeckhaut, Venessa; Eeckhout, Mia; De Saeger, Sarah; Hessenberger, Sabine; Martel, An; Croubels, Siska

    2014-01-01

    Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (Penteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens.

  6. Predisposing factors, diagnosis, treatment and prognosis of cerebral venous thrombosis during pregnancy and postpartum: a case-control study

    Institute of Scientific and Technical Information of China (English)

    GAO Hui; YANG Bao-jun; JIN Li-ping; JIA Xiao-fang

    2011-01-01

    Background Previous investigations have demonstrated a relatively low incidence of stroke among young women,though both pregnancy and delivery can substantially increase the risk.Cerebral venous thrombosis may manifest different characteristics during pregnancy and postpartum as a result of their specific physiological statuses.This study aimed to identify the clinical manifestations,diagnosis,treatment,and prognosis of cerebral venous thrombosis during pregnancy and postpartum.Methods We conducted a retrospective analysis of 22 patients with cerebral venous thrombosis who were assigned to either group A (during pregnancy) or group B (during postpartum).The relevant risk factors,initiation and development of the disease,clinical presentations,diagnosis,treatment,and prognosis were compared between the two stages.Results Cerebral venous thrombosis occurred during both pregnancy and postpartum,but was more common postpartum.Patients in group A had a longer hospitalization period than those in group B.Confirmed predisposing factors in 85.7% of patients of group A were dehydration,infection,and underlying cerebrovascular disorders.No obvious predisposing factors were identified in group B.The most frequent symptom was headache,with epileptic seizures,hemiparalysis and aphasia being less frequent symptoms.Focal neurological symptoms (P=0.022) and cerebral infarction (P=0.014) occurred more frequently in group A than in group B.Anticoagulation therapy proved to be safe for cerebral venous thrombosis patients during puerperium,regardless of parenchymal hemorrhage.However,more attention should be paid to spontaneous in-site placental hemorrhage in pregnant patients.Both groups had similar prognoses (P=1.000),with 36.3% patients suffering from consequential dysfunction or recurrent intracranial hypertension.Delayed diagnosis was associated with a poorer prognosis.Conclusions Cerebral venous thrombosis manifests different clinical characteristics during pregnancy and

  7. Lung infarction following pulmonary embolism. A comparative study on clinical conditions and CT findings to identify predisposing factors

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, J.; Obermann, A.; Stueckradt, S.; Tueshaus, C. [General Hospital Hagen (Germany). Radiology; Goltz, J.; Kickuth, R. [University Hospital Wuerzburg (Germany). Radiology; Liermann, D. [University Hospital Marienhospital Herne (Germany). Radiology

    2015-06-15

    The aim of this study was to identify factors predisposing to lung infarction in patients with pulmonary embolism (PE). We performed a retrospective analysis on 154 patients with the final diagnosis of PE being examined between January 2009 and December 2012 by means of a Toshiba Aquilion 64 CT scanner. The severity of clinical symptoms was defined by means of a clinical index with 4 classes. The pulmonary clot load was quantified using a modified severity index of PE as proposed by Miller. We correlated several potential predictors of pulmonary infarction such as demographic data, pulmonary clot burden, distance of total vascular obstruction and pleura, the presence of cardiac congestion, signs of chronic bronchitis or emphysema with the occurrence of pulmonary infarction. Computed tomography revealed 78 areas of pulmonary infarction in 45/154 (29.2%) patients. The presence of infarction was significantly higher in the right lung than in the left lung (p < 0.001). We found no correlation between pulmonary infarction and the presence of accompanying malignant diseases (r=-0.069), signs of chronic bronchitis (r=-0.109), cardiac congestion (r=-0.076), the quantified clot burden score (r=0.176), and the severity of symptoms (r=-0.024). Only a very weak negative correlation between the presence of infarction and age (r=-0.199) was seen. However, we could demonstrate a moderate negative correlation between the distance of total vascular occlusion and the occurrence of infarction (r=-0.504). Neither cardiac congestion nor the degree of pulmonary vascular obstruction are main factors predisposing to pulmonary infarction in patients with PE. It seems that a peripheral total vascular obstruction more often results in infarction than even massive central clot burden.

  8. The mycotoxin deoxynivalenol predisposes for the development of Clostridium perfringens-induced necrotic enteritis in broiler chickens.

    Directory of Open Access Journals (Sweden)

    Gunther Antonissen

    Full Text Available Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (P<0.001. DON significantly reduced the transepithelial electrical resistance in duodenal segments (P<0.001 and decreased duodenal villus height (P = 0.014 indicating intestinal barrier disruption and intestinal epithelial damage, respectively. This may lead to an increased permeability of the intestinal epithelium and decreased absorption of dietary proteins. Protein analysis of duodenal content indeed showed that DON contamination resulted in a significant increase in total protein concentration (P = 0.023. Furthermore, DON had no effect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens.

  9. Replacing sugary drinks with milk is inversely associated with weight gain among young obesity-predisposed children.

    Science.gov (United States)

    Zheng, Miaobing; Rangan, Anna; Allman-Farinelli, Margaret; Rohde, Jeanett Friis; Olsen, Nanna Julie; Heitmann, Berit Lilienthal

    2015-11-14

    The aim of the present study was to examine the associations of sugary drink consumption and its substitution with alternative beverages with body weight gain among young children predisposed to future weight gain. Secondary analysis of the Healthy Start Study, a 1·5-year randomised controlled trial designed to prevent overweight among Danish children aged 2-6 years (n 366), was carried out. Multivariate linear regression models were used to investigate the associations of beverage consumption with change in body weight (Δweight) or BMI(ΔBMI) z-score. Substitution models were used to extrapolate the influence of replacing sugary drinks with alternative beverages (water, milk and diet drinks) on Δweight or ΔBMI z-score. Sugary drink intake at baseline and substitution of sugary drinks with milk were associated with both Δweight and ΔBMI z-score. Every 100 g/d increase in sugary drink intake was associated with 0·10 kg and 0·06 unit increases in body weight (P=0·048) and BMI z-score (P=0·04), respectively. Substitution of 100 g/d sugary drinks with 100 g/d milk was inversely associated with Δweight (β=-0·16 kg; P=0·045) and ΔBMI z-score (β=-0·07 units; P=0·04). The results of this study suggest that sugary drink consumption was associated with body weight gain among young children with high predisposition for future overweight. In line with the current recommendations, sugary drinks, whether high in added or natural sugar, should be discouraged to help prevent childhood obesity. Milk may be a good alternative to sugary drinks with regard to weight management among young obesity-predisposed children.

  10. Overexpression of vsr in Escherichia coli is mutagenic.

    Science.gov (United States)

    Doiron, K M; Viau, S; Koutroumanis, M; Cupples, C G

    1996-01-01

    Overexpression of vsr in Escherichia coli stimulates transition and frameshift mutations. The pattern of mutations suggests that mutagenesis is due to saturation or inactivation of dam-directed mismatch repair. PMID:8763960

  11. [Overexpression of FKS1 to improve yeast autolysis-stress].

    Science.gov (United States)

    Li, Jia; Wang, Jinjing; Li, Qi

    2015-09-01

    With the development of high gravity brewing, yeast cells are exposed to multiple brewing-associated stresses, such as increased osmotic pressure, enhanced alcohol concentration and nutritional imbalance. These will speed up yeast autolysis, which seriously influence beer flavor and quality. To increase yeast anti-autolytic ability, FKS1 overexpression strain was constructed by 18S rDNA. The concentration of β-1,3-glucan of overexpression strain was 62% higher than that of wild type strain. Meantime, FKS1 overexpression strain increased anti-stress ability at 8% ethanol, 0.4 mol/L NaCl and starvation stress. Under simulated autolysis, FKS1 showed good anti-autolytic ability by slower autolysis. These results confirms the potential of FKS1 overexpression to tackle yeast autolysis in high-gravity brewing.

  12. 甲状腺癌易感基因的研究进展%Research progression of thyroid carcimoma's predisposing genes

    Institute of Scientific and Technical Information of China (English)

    迟晓云; 焦淑贤

    2011-01-01

    甲状腺癌是多因素参与的一类复杂性疾病,其病因及发病机制尚不完全清楚.研究表明环境因素与遗传易感因素相互作用是大多数肿瘤的病因,并且遗传易感因素起关键作用.本文就国内外对甲状腺癌易感基因的研究进展做一综述.%Thyroid carcimoma is a complex desease participated of multiple factors.Which etiopathogenisis and invasion mechanism is unknown.Investigation indicated that the interaction of environmental fator and descent predisposing fator was majority carcinoma's etiopathogenisis , and descent predisposing fator was more important.This article reviewed the globle research progression of thyroid carcimoma's predisposing genes.

  13. Are adolescent idiopathic scoliosis and ankylosing spondylitis counter-opposing conditions? A hypothesis on biomechanical contributions predisposing to these spinal disorders.

    Science.gov (United States)

    Masi, A T; Dorsch, J L; Cholewicki, J

    2003-01-01

    Human spinal biomechanics are profoundly complex and not well understood, especially in terms of the dynamic spine function. Translation of biomechanics to disease is difficult, particularly since cause must be separated from effect. Primary dynamics predisposing to the onset of chronic spinal disorders, e.g., adolescent idiopathic scoliosis (AIS) or ankylosing spondylitis (AS), must clearly be differentiated from secondary alterations. This commentary addresses primary biomechanics that may predispose to these idiopathic diseases. A novel hypothesis is proposed, based upon inferences regarding their contrasting muscular dynamics. The hypothesis postulates opposing inherent muscle tonicity in AIS versus AS. Converse degrees of spinal stability may predispose to the respective curvature deformities of AIS and the enthesopathy lesions of AS. One condition is suspected to counter-oppose the other, within a polymorphic spectrum of spinal stability.

  14. Avaliação dos fatores predisponentes nas instabilidades femoropatelares Avaliation of predisposing factors in patellofemoral instabilities

    Directory of Open Access Journals (Sweden)

    Ricardo Carli Burmann

    2011-01-01

    Full Text Available OBJETIVO: Avaliar a prevalência dos fatores predisponentes à instabilidade femoropatelar (displasia de tróclea, patela alta, TAGT, báscula patelar em um grupo de pacientes acompanhados em nível ambulatorial. MÉTODOS: Avaliou-se 70 pacientes, sendo 52 do sexo feminino (74,28% e 18 (25,72% do sexo masculino, num total de 127 joelhos, com uma média de idade de 17,71 anos. A avaliação por imagem foi realizada através de radiografias e tomografia computadorizada. As instabilidades femoropatelares foram classificadas seguindo-se a classificação de Henri Dejour (instabilidade maior, objetiva e potencial. Enquadraram-se as displasias trocleares de acordo com a classificação de David Dejour (tipo A, B, C, D. RESULTADOS: Observou-se displasia troclear em 118 (92,91% joelhos, sendo 91 (77,11% joelhos dos tipos A e B. A altura patelar apresentou uma média de 1,23, com 44 (34,64% consideradas patela alta e 83 (65,36% normais. A báscula patelar alterada foi encontrada em 92 (72,44% joelhos e a elevação da TAGT em 63 (49,60% joelhos. Obteve-se predominância de instabilidades objetivas 89 (70,07% joelhos, Quanto a associação de fatores predisponentes,, 117 (92,13% joelhos apresentaram mais quem um fator. CONCLUSÕES: A instabilidade femoropatelar é uma doença multifatorial, os distúrbios trocleares são mais prevalentes e há uma forte associação entre 2 ou mais fatores predisponentes.OBJECTIVE: To evaluate the prevalence of predisposing factors for femoropatelar instability (dysplasia of the trochlea, high patella, TTTG, and patellar tilt in a group of patients in outpatient follow-up. METHODS: 70 patients were evaluated; 52 (74.28 % female and 18 (25.72 % male, with an average age of 17.71 years and a total of 127 knees. The evaluation by imaging was carried out through radiologic examination and computerized tomography. The femoropatelar instabilities were classified according to Henri Dejour's classification (major, objective and

  15. Predisposing and Enabling Factors Associated with Mammography Use among Hispanic and Non-Hispanic White Women Living in a Rural Area

    Science.gov (United States)

    Tejeda, Silvia; Thompson, Beti; Coronado, Gloria D.; Martin, Diane P.; Heagerty, Patrick J.

    2009-01-01

    Context: Women who do not receive regular mammograms are more likely than others to have breast cancer diagnosed at an advanced stage. Purpose: To examine predisposing and enabling factors associated with mammography use among Hispanic and non-Hispanic White women. Methods: Baseline data were used from a larger study on cancer prevention in rural…

  16. ANALYSIS OF PREDISPOSING FACTORS TO ABORTION IN WOMEN OF THE FIRST PERIOD OF MATURE AGE OF DIFFERENT SOMATOTYPES WITH 22 - 27 WEEKS GESTATIONAL PERIOD

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    L. V. Muzurova

    2008-12-01

    Full Text Available Frequency of occurance ofdifferent somatotypes and predisposing factors to abortion in women at the age of 22 to 35 of the 2-nd trimester of pregnancy has been understudy. It is determined the women with different somatotypes are characterized by different frequency of occurance of extragenital and genital pathology

  17. Examining the Diet of Post-Migrant Hispanic Males Using the Precede-Proceed Model: Predisposing, Reinforcing, and Enabling Dietary Factors

    Science.gov (United States)

    Castellanos, Diana Cuy; Downey, Laura; Graham-Kresge, Susan; Yadrick, Kathleen; Zoellner, Jamie; Connell, Carol L.

    2013-01-01

    Objective: To examine socio-environmental, behavioral, and predisposing, reinforcing, and enabling (PRE) factors contributing to post-migration dietary behavior change among a sample of traditional Hispanic males. Design: In this descriptive study, semistructured interviews, a group interview, and photovoice, followed by group interviews, were…

  18. Targeted overexpression of amelotin disrupts the microstructure of dental enamel.

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    Rodrigo S Lacruz

    Full Text Available We have previously identified amelotin (AMTN as a novel protein expressed predominantly during the late stages of dental enamel formation, but its role during amelogenesis remains to be determined. In this study we generated transgenic mice that produce AMTN under the amelogenin (Amel gene promoter to study the effect of AMTN overexpression on enamel formation in vivo. The specific overexpression of AMTN in secretory stage ameloblasts was confirmed by Western blot and immunohistochemistry. The gross histological appearance of ameloblasts or supporting cellular structures as well as the expression of the enamel proteins amelogenin (AMEL and ameloblastin (AMBN was not altered by AMTN overexpression, suggesting that protein production, processing and secretion occurred normally in transgenic mice. The expression of Odontogenic, Ameloblast-Associated (ODAM was slightly increased in secretory stage ameloblasts of transgenic animals. The enamel in AMTN-overexpressing mice was much thinner and displayed a highly irregular surface structure compared to wild type littermates. Teeth of transgenic animals underwent rapid attrition due to the brittleness of the enamel layer. The microstructure of enamel, normally a highly ordered arrangement of hydroxyapatite crystals, was completely disorganized. Tomes' process, the hallmark of secretory stage ameloblasts, did not form in transgenic mice. Collectively our data demonstrate that the overexpression of amelotin has a profound effect on enamel structure by disrupting the formation of Tomes' process and the orderly growth of enamel prisms.

  19. Oral squamous cell carcinoma in patients with and without predisposing habits in glossal and extra-glossal site: An institutional experience in South India

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    K Ranganathan

    2015-01-01

    Full Text Available INTRODUCTION: We report our cohort of oral squamous cell carcinoma (OSCC patients with or without predisposing habits in glossal and extraglossal sites. MATERIALS AND METHODS: A retrospective analysis of OSCC cases over a period of 13.75 years from the archives of Ragas Dental College and Hospital, Chennai, India. Demographic details, site, details of habits, and grade of OSCC were retrieved. Social Package for Social Service version 17.0 was used to analyze the data. Descriptive statistics, Chi-square test, and comparison of mean were employed appropriately. RESULTS: There were 151 OSCC cases, of which 60.9% (92/151 were males, 21.2% (32/151 were aged ≤40 years and 27.82% (42/151 occurred in the tongue. The glossal to extraglossal site ratio was 1:2.6. Predisposing habits were present in 52.4% of glossal OSCC and 82.6% with extra-glossal sites (P = 0.000. Besides tobacco, exclusive areca nut chewing was observed in 15.23% (23/151 patients. Thirty-nine (25.8% belonged to non-tobacco, non-areca nut, non-alcohol (NTND group with male to female ratio was1:3. DISCUSSION: In our cohort, 112 of 151 OSCC (74.8% had at least one predisposing habit. Chewing of areca nut alone was a predisposing habit by itself. In addition, there was a small, subset of cases that were not associated with history of any habits. This study brings to focus the subsets of OSCC predisposed by areca nut and NTND, that needs to be studied further.

  20. Combinatorial method for overexpression of membrane proteins in Escherichia coli.

    Science.gov (United States)

    Leviatan, Shani; Sawada, Keisuke; Moriyama, Yoshinori; Nelson, Nathan

    2010-07-30

    Membrane proteins constitute 20-30% of all proteins encoded by the genome of various organisms. Large amounts of purified proteins are required for activity and crystallization attempts. Thus, there is an unmet need for a heterologous membrane protein overexpression system for purification, crystallization, and activity determination. We developed a combinatorial method for overexpressing and purifying membrane proteins using Escherichia coli. This method utilizes short hydrophilic bacterial proteins, YaiN and YbeL, fused to the ends of the membrane proteins to serve as facilitating factors for expression and purification. Fourteen prokaryotic and mammalian membrane proteins were expressed using this system. Moderate to high expression was obtained for most proteins, and detergent solubilization combined with a short purification process produced stable, monodispersed membrane proteins. Five of the mammalian membrane proteins, overexpressed using our system, were reconstituted into liposomes and exhibited transport activity comparable with the native transporters.

  1. Combinatorial Method for Overexpression of Membrane Proteins in Escherichia coli*

    Science.gov (United States)

    Leviatan, Shani; Sawada, Keisuke; Moriyama, Yoshinori; Nelson, Nathan

    2010-01-01

    Membrane proteins constitute 20–30% of all proteins encoded by the genome of various organisms. Large amounts of purified proteins are required for activity and crystallization attempts. Thus, there is an unmet need for a heterologous membrane protein overexpression system for purification, crystallization, and activity determination. We developed a combinatorial method for overexpressing and purifying membrane proteins using Escherichia coli. This method utilizes short hydrophilic bacterial proteins, YaiN and YbeL, fused to the ends of the membrane proteins to serve as facilitating factors for expression and purification. Fourteen prokaryotic and mammalian membrane proteins were expressed using this system. Moderate to high expression was obtained for most proteins, and detergent solubilization combined with a short purification process produced stable, monodispersed membrane proteins. Five of the mammalian membrane proteins, overexpressed using our system, were reconstituted into liposomes and exhibited transport activity comparable with the native transporters. PMID:20525689

  2. Prospective implementation of a software application for pre-disposal L/ILW waste management activities in Romania

    Energy Technology Data Exchange (ETDEWEB)

    Fako, Raluca; Sociu, Florin; Stan, Camelia; Georgescu, Roxana; Barariu, Gheorghe [National Authority for Nuclear Activity - Subsidiary of Technology and Engineering for Nuclear Projects, 409 Atomistilor Str., P.O. Box 5204, Mg4 Magurele, Ilfov (Romania)

    2013-07-01

    Romania is actively engaged to update the Medium and Long Term National Strategy for Safe Management of Radioactive Waste and to approve the Road Map for Geological Repository Development. Considering relevant documents to be further updated, about 122,000 m{sup 3} SL-LILW are to be disposed in a near surface facility that will have room, also, for quantities of VLLW. Planned date for commissioning is under revision. Taking into account that in this moment there are initiated several actions for the improvement of the technical capability for LILW treatment and conditioning, several steps for the possible use of SAFRAN software were considered. In view of specific data for Romanian radioactive waste inventory, authors are trying to highlight the expected limitations and unknown data related with the implementation of SAFRAN software for the foreseen pre-disposal waste management activities. There are challenges that have to be faced in the near future related with clear definition of the properties of each room, area and waste management activity. This work has the aim to address several LILW management issues in accordance with national and international regulatory framework for the assurance of nuclear safety. Also, authors intend to develop their institutional capability for the safety demonstration of the existent and future radioactive waste management facilities and activities. (authors)

  3. Aspergillus citrinoterreus, a new species of section Terrei isolated from samples of patients with nonhematological predisposing conditions.

    Science.gov (United States)

    Guinea, Jesús; Sandoval-Denis, Marcelo; Escribano, Pilar; Peláez, Teresa; Guarro, Josep; Bouza, Emilio

    2015-02-01

    The use of molecular identification techniques has revealed an increasing number of new species within Aspergillus section Terrei. We phenotyped a set of 26 clinical isolates that showed genetic differences from Aspergillus terreus sensu stricto by analyzing sequences from PCR-amplified β-tubulin and calmodulin genes and the internal transcribed spacer region. Since the isolates were phylogenetically and morphologically different from all of the members of Aspergillus section Terrei, they are described here as a new species, Aspergillus citrinoterreus, so named because it produces a diffusible yellowish pigment in agar. A. citrinoterreus isolates were significantly more susceptible to itraconazole, voriconazole, and posaconazole than A. terreus sensu stricto isolates were; in contrast, the amphotericin B MICs for both species were high. A. citrinoterreus was found in clinical samples from patients with proven or probable invasive aspergillosis and colonized patients, none of whom had hematological malignancies as predisposing conditions. However, they did have other underlying conditions such as chronic obstructive pulmonary disease, cirrhosis, and cancer or had received a solid organ transplants and presented not only with invasive pulmonary aspergillosis but also with mediastinitis. A. citrinoterreus isolates were detected for the first time in 2002. In all cases of invasive aspergillosis, A. citrinoterreus was found to be a copathogen, mostly with A. fumigatus.

  4. Detection of a Tumor Suppressor Gene Variant Predisposing to Colorectal Cancer in an 18th Century Hungarian Mummy.

    Science.gov (United States)

    Feldman, Michal; Hershkovitz, Israel; Sklan, Ella H; Kahila Bar-Gal, Gila; Pap, Ildikó; Szikossy, Ildikó; Rosin-Arbesfeld, Rina

    2016-01-01

    Mutations of the Adenomatous polyposis coli (APC) gene are common and strongly associated with the development of colorectal adenomas and carcinomas. While extensively studied in modern populations, reports on visceral tumors in ancient populations are scarce. To the best of our knowledge, genetic characterization of mutations associated with colorectal cancer in ancient specimens has not yet been described. In this study we have sequenced hotspots for mutations in the APC gene isolated from 18th century naturally preserved human Hungarian mummies. While wild type APC sequences were found in two mummies, we discovered the E1317Q missense mutation, known to be a colorectal cancer predisposing mutation, in a large intestine tissue of an 18th century mummy. Our data suggests that this genetic predisposition to cancer already existed in the pre-industrialization era. This study calls for similar investigations of ancient specimens from different periods and geographical locations to be conducted and shared for the purpose of obtaining a larger scale analysis that will shed light on past cancer epidemiology and on cancer evolution.

  5. Detection of a Tumor Suppressor Gene Variant Predisposing to Colorectal Cancer in an 18th Century Hungarian Mummy.

    Directory of Open Access Journals (Sweden)

    Michal Feldman

    Full Text Available Mutations of the Adenomatous polyposis coli (APC gene are common and strongly associated with the development of colorectal adenomas and carcinomas. While extensively studied in modern populations, reports on visceral tumors in ancient populations are scarce. To the best of our knowledge, genetic characterization of mutations associated with colorectal cancer in ancient specimens has not yet been described. In this study we have sequenced hotspots for mutations in the APC gene isolated from 18th century naturally preserved human Hungarian mummies. While wild type APC sequences were found in two mummies, we discovered the E1317Q missense mutation, known to be a colorectal cancer predisposing mutation, in a large intestine tissue of an 18th century mummy. Our data suggests that this genetic predisposition to cancer already existed in the pre-industrialization era. This study calls for similar investigations of ancient specimens from different periods and geographical locations to be conducted and shared for the purpose of obtaining a larger scale analysis that will shed light on past cancer epidemiology and on cancer evolution.

  6. Fournier’s Gangrene after Open Hemorrhoidectomy without a Predisposing Factor: Report of a Case and Review of the Literature

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    Guldeniz Karadeniz Cakmak

    2009-05-01

    Full Text Available Fournier’s gangrene (FG is a fatal synergistic infectious disease with necrotizing fasciitis of the perineum and abdominal wall along with the scrotum and penis in men and vulva in women. An unpredictable case of FG two weeks after open hemorrhoidectomy in a previously healthy 55-year-old male is described. Full-thickness patchy skin necrosis of the perianal, perineal and scrotal region associated with rectal perforation was detected on admission. Prompt radical debridement together with aggressive fluid resuscitation and broad-spectrum antibiotic administration was initiated. Because of rectal involvement, diverting sigmoid colostomy was fashioned. The patient survived after two additional local debridements. Nevertheless, loss of sphincter function due to massive muscle destruction led to permanent colostomy. Our case together with others reported in the literature illustrates that, although rare, FG after open hemorrhoidectomy represents a life-threatening complication to otherwise healthy patients. The development of fever and urinary retention should draw the attention of the surgeon, even if the presentation is delayed. The current literature only briefly mentions the potential risk of FG after such a common surgical procedure. However, devastating complications occur more often than anticipated. This disastrous complication without predisposing factor is discussed along with a literature review.

  7. Developmental androgen excess programs sympathetic tone and adipose tissue dysfunction and predisposes to a cardiometabolic syndrome in female mice.

    Science.gov (United States)

    Nohara, Kazunari; Waraich, Rizwana S; Liu, Suhuan; Ferron, Mathieu; Waget, Aurélie; Meyers, Matthew S; Karsenty, Gérard; Burcelin, Rémy; Mauvais-Jarvis, Franck

    2013-06-15

    Among women, the polycystic ovarian syndrome (PCOS) is considered a form of metabolic syndrome with reproductive abnormalities. Women with PCOS show increased sympathetic tone, visceral adiposity with enlarged adipocytes, hypoadiponectinemia, insulin resistance, glucose intolerance, increased inactive osteocalcin, and hypertension. Excess fetal exposure to androgens has been hypothesized to play a role in the pathogenesis of PCOS. Previously, we showed that neonatal exposure to the androgen testosterone (NT) programs leptin resistance in adult female mice. Here, we studied the impact of NT on lean and adipose tissues, sympathetic tone in cardiometabolic tissues, and the development of metabolic dysfunction in mice. Neonatally androgenized adult female mice (NTF) displayed masculinization of lean tissues with increased cardiac and skeletal muscle as well as kidney masses. NTF mice showed increased and dysfunctional white adipose tissue with increased sympathetic tone in both visceral and subcutaneous fat as well as increased number of enlarged and insulin-resistant adipocytes that displayed altered expression of developmental genes and hypoadiponectinemia. NTF exhibited dysfunctional brown adipose tissue with increased mass and decreased energy expenditure. They also displayed decreased undercarboxylated and active osteocalcin and were predisposed to obesity during chronic androgen excess. NTF showed increased renal sympathetic tone associated with increased blood pressure, and they developed glucose intolerance and insulin resistance. Thus, developmental exposure to testosterone in female mice programs features of cardiometabolic dysfunction, as can be observed in women with PCOS, including increased sympathetic tone, visceral adiposity, insulin resistance, prediabetes, and hypertension.

  8. Identification of two lineages of host-associated eriophyoid mites predisposed to different levels of host diversification.

    Science.gov (United States)

    Li, Hao-Sen; Hoffmann, Ary A; Guo, Jing-Feng; Zuo, Yun; Xue, Xiao-Feng; Pang, Hong; Hong, Xiao-Yue

    2016-12-01

    Herbivorous arthropods can diversify as a consequence of evolutionary changes in response to their plant hosts. Current patterns of host association of herbivores are likely to reflect a long evolutionary history of herbivore-plant co-evolution. Here, we used molecular phylogenetics to track the evolutionary history of host shifts and diversification of 66 eriophyoid mites (Acari, Eriophyoidea), and linked past patterns of evolutionary diversification to more recent patterns of divergence by tracking population genetic variation in 13 of the eriophyoid mite species feeding on different gymnosperm hosts. This allowed us to explore the relationship between a past history of diversification and the current potential of mites to undergo host range shifts. We found that population-level diversity across gymnosperm hosts as measured by 28S rRNA markers was greater in species from the mite clade that had radiated across evolutionary time to utilize a variety of hosts including angiosperms, compared to species from the clade that has remained restricted to ancestral gymnosperm hosts. Species from the radiated clade exhibited higher variation in host use. Lineages of mites that have in the past been able to radiate and adapt to diverse plants may therefore be predisposed to continue their expansion on new hosts, although additional clades need to be tested.

  9. Cigarette Smoke-Induced Lung Disease Predisposes to More Severe Infection with Nontypeable Haemophilus influenzae: Protective Effects of Andrographolide.

    Science.gov (United States)

    Tan, W S Daniel; Peh, Hong Yong; Liao, Wupeng; Pang, Chu Hui; Chan, Tze Khee; Lau, Suk Hiang; Chow, Vincent T; Wong, W S Fred

    2016-05-27

    Cigarette smoke (CS) is associated with many maladies, one of which is chronic obstructive pulmonary disease (COPD). As the disease progresses, patients are more prone to develop COPD exacerbation episodes by bacterial infection, particularly to nontypeable Haemophilus influenza (NTHi) infection. The present study aimed to develop a CS-exposed mouse model that increases inflammation induced by NTHi challenge and investigate the protective effects of andrographolide, a bioactive molecule with anti-inflammatory and antioxidant properties isolated from the plant Andrographis paniculata. Female BALB/c mice exposed to 2 weeks of CS followed by a single intratracheal instillation of NTHi developed increased macrophage and neutrophil pulmonary infiltration, augmented cytokine levels, and heightened oxidative damage. Andrographolide effectively reduced lung cellular infiltrates and decreased lung levels of TNF-α, IL-1β, CXCL1/KC, 8-OHdG, matrix metalloproteinase-8 (MMP-8), and MMP-9. The protective actions of andrographolide on CS-predisposed NTHi inflammation might be attributable to increased nuclear factor erythroid-2-related factor 2 (Nrf2) activation and decreased Kelch-like ECH-associated protein 1 (Keap1) repressor function, resulting in enhanced gene expression of antioxidant enzymes including heme oxygenase-1 (HO-1), glutathione reductase (GR), glutathione peroxidase-2 (GPx-2), glutamate-cysteine ligase modifier (GCLM), and NAD(P)H quinone oxidoreductase 1 (NQO1). Taken together, these findings strongly support a therapeutic potential for andrographolide in preventing lung inflammation caused by NTHi in cigarette smokers.

  10. Prevalence of Geographic tongue and Related Predisposing Factors in 7-18 Year-Old Students in Kermanshah, Iran 2014.

    Science.gov (United States)

    Rezaei, Fatemeh; Safarzadeh, Mina; Mozafari, Hamidreza; Tavakoli, Payam

    2015-01-01

    Geographic tongue is a benign lesion at the dorsum and margins of the tongue that sometimes causes pain and burning sensation. This lesion is characterized by an erythematous area with white or yellow folded edges. The predisposing factors of this lesion include heredity, allergies, psoriasis, stress, fissured tongue and consumption of some foods. The present study was conducted to investigate the prevalence of geographic tongue and its related factors among the 7-18 year-old students in Kermanshah, Iran. This descriptive cross-sectional study was carried out in three schools in Kermanshah using multi-stage random cluster sampling method. A total number of 3600