Kohno T.,National Cancer Center Research Institute |
Otsuka A.,National Cancer Center Research Institute |
Girard L.,University of Texas Southwestern Medical Center |
Sato M.,National Cancer Center Research Institute |
And 5 more authors.
Genes Chromosomes and Cancer
A total of 176 genes homozygously deleted in human lung cancer were identified by DNA array-based whole genome scanning of 52 lung cancer cell lines and subsequent genomic PCR in 74 cell lines, including the 52 cell lines scanned. One or more exons of these genes were homozygously deleted in one (1%) to 20 (27%) cell lines. These genes included known tumor suppressor genes, e.g., CDKN2A/p16, RB1, and SMAD4, and candidate tumor suppressor genes whose hemizygous or homozygous deletions were reported in several types of human cancers, such as FHIT, KEAP1, and LRP1B/LRP-DIP. CDKN2A/p16 and p14ARF located in 9p21 were most frequently deleted (20/74, 27%). The PTPRD gene was most frequently deleted (8/74, 11%) among genes mapping to regions other than 9p21. Somatic mutations, including a nonsense mutation, of the PTPRD gene were detected in 8/74 (11%) of cell lines and 4/95 (4%) of surgical specimens of lung cancer. Reduced PTPRD expression was observed in the majority (>80%) of cell lines and surgical specimens of lung cancer. Therefore, PTPRD is a candidate tumor suppressor gene in lung cancer. Microarray-based expression profiling of 19 lung cancer cell lines also indicated that some of the 176 genes, such as KANK and ADAMTS1, are preferentially inactivated by epigenetic alterations. Genetic/epigenetic as well as functional studies of these 176 genes will increase our understanding of molecular mechanisms behind lung carcinogenesis. © 2010 Wiley-Liss, Inc. Source
Pallante P.,University of Naples Federico II |
Malapelle U.,University of Naples Federico II |
Berlingieri M.T.,University of Naples Federico II |
Bellevicine C.,University of Naples Federico II |
And 8 more authors.
European Journal of Cancer
Introduction: UbcH10 codes for the cancer related E2 Ubiquitin Conjugating Enzyme, an enzymatic molecule with a key role in the ubiquitin-proteasome pathway. Current studies have suggested a critical role of UbcH10 in a variety of malignancies, including human thyroid, breast, ovarian and colorectal carcinomas. The aim of this study has been to extend the analysis of UbcH10 expression to lung cancer. This neoplasia represents one of the leading cause of cancer mortality worldwide, and new tools for an accurate diagnosis/prognosis are needed. Methods: The expression levels of UbcH10 were analysed in human non-small cell lung carcinoma (NSCLC) by quantitative RT-PCR and tissue microarray immunohistochemistry, and these values were correlated with the clinicopathological features of the patients affected by NSCLC. Results: Our results demonstrate that UbcH10 is overexpressed in NSCLC compared to the normal lung tissue. Moreover, UbcH10 expression is significantly higher in squamous cell and large cell carcinomas than in adenocarcinomas, and directly and inversely correlated with the mutational status of p53 and EGFR, respectively. The suppression of UbcH10 expression by RNAi resulted in a drastic reduction of proliferation and migration abilities of lung carcinoma cell lines. Conclusion: These results, taken together, indicate that UbcH10 overexpression has a critical role in lung carcinogenesis, and the evaluation of UbcH10 expression levels may be a new tool for the characterisation of NSCLC. © 2012 Elsevier Ltd. All rights reserved. Source
Garcia-Linares C.,Institute Of Medicina Predictiva I Personalitzada Del Cancer Imppc |
Garcia-Linares C.,Institute Dinvestigacio Biomedica Of Bellvitge Idibell |
Fernandez-Rodriguez J.,Institute Catala Doncologia Ico Idibell |
Terribas E.,Institute Of Medicina Predictiva I Personalitzada Del Cancer Imppc |
And 12 more authors.
Dermal neurofibromas (dNFs) are benign tumors of the peripheral nervous system typically associated with Neurofibromatosis type 1 (NF1) patients. Genes controlling the integrity of the DNA are likely to influence the number of neurofibromas developed because dNFs are caused by somatic mutational inactivation of the NF1 gene, frequently evidenced by loss of heterozygosity (LOH). We performed a comprehensive analysis of the prevalence and mechanisms of LOH in dNFs. Our study included 518 dNFs from 113 patients. LOH was detected in 25% of the dNFs (N = 129). The most frequent mechanism causing LOH was mitotic recombination, which was observed in 62% of LOH-tumors (N = 80), and which does not reduce the number of NF1 gene copies. All events were generated by a single crossover located between the centromere and the NF1 gene, resulting in isodisomy of 17q. LOH due to the loss of the NF1 gene accounted for a 38% of dNFs with LOH (N = 49), with deletions ranging in size from ~80 kb to ~8 Mb within 17q. In one tumor we identified the first example of a neurofibroma-associated second-hit type-2 NF1 deletion. Analysis of the prevalence of mechanisms causing LOH in dNFs in individual patients (possibly under genetic control) will elucidate whether there exist interindividual variation. © 2010 Wiley-Liss, Inc. Source
Pros E.,Genes and Cancer Group |
Lantuejoul S.,Grenoble University Hospital Center |
Sanchez-Verde L.,Immunohistochemistry Histology Unit |
Castillo S.D.,Genes and Cancer Group |
And 10 more authors.
International Journal of Cancer
Growth factor receptors (GFRs) are amenable to therapeutic intervention in cancer and it is important to select patients appropriately. One of the mechanisms for activation of GFRs is gene amplification (GA) but discrepancies arising from the difficulties associated with data interpretation and the lack of agreed parameters confound the comparison of results from different laboratories. Here, we attempt to establish appropriate conditions for standardization of the determination of GA in a panel of GFRs. A NSCLC tissue microarray panel containing 302 samples was screened for alterations at ALK, FGFR1, FGFR2, FGFR3, ERBB2, IGF1R, KIT, MET and PDGFRA by FISH, immunostaining and/or real-time quantitative RT-PCR. Strong amplification was found for FGFR1, ERBB2, KIT/PDFGRA and MET, with frequencies ranging from 1 to 6%. Thresholds for overexpression and GA were established. Strong immunostaining was found in most tumors with ERBB2, MET and KIT amplification, although some tumors underwent strong immunostaining in the absence of GA. KIT and PDFGRA were always coamplified, but only one tumor showed PDGFRA overexpression, indicating that KIT is the main target. Amplification of FGFR1 predominated in squamous cell carcinomas, although the association with overexpression was inconclusive. Interestingly, alterations at ALK, MET, EGFR, ERBB2 and KRAS correlated with augmented levels of phospho-S6 protein, suggesting activation of the mTOR pathway, which may prove useful to pre-select tumors for testing. Overall, here, we provide with parameters for the determination of GA at ERBB2, MET, KIT and PDGFRA which could be implemented in the clinic to stratify lung cancer patients for specific treatments. What's new? Targeting growth factor receptors is a good way to treat cancer, in the right patients. Therefore, it's important to be able to identify patients with alterations in relevant GFRs. One way they get activated is by gene amplification, but it can be tricky to establish whether amplification has taken place. This study provides the first comprehensive analysis of gene copy number and gene expression alteration in non-small cell lung carcinoma (NSCLC). By combining the analyses of alterations at the DNA, mRNA, and protein levels for certain growth factors in a panel of 300 NSCLC, the authors were able to identify those tumors that carry gene amplifications. These new results establish parameters for gene amplification that will be useful for routine screening. Copyright © 2013 UICC. Source
Romero O.A.,Genes and Cancer Group |
Torres-Diz M.,Genes and Cancer Group |
Pros E.,Genes and Cancer Group |
Savola S.,MRC Holland |
And 10 more authors.
Our knowledge of small cell lung cancer (SCLC) genetics is still very limited, ampli-fication of L-MYC, N-MYC, and C-MYC being some of the well-established gene alterations. Here, we report our discovery of tumor-specific inactivation of the MYC-associated factor X gene, MAX, in SCLC. MAX inactivation is mutually exclusive with alterations of MYC and BRG1, the latter coding for an ATPase of the switch/sucrose nonfermentable (SWI/SNF) complex. We demonstrate that BRG1 regulates the expression of MAX through direct recruitment to the MAX promoter, and that depletion of BRG1 strongly hinders cell growth, specifically in MAX-deficient cells, heralding a synthetic lethal interaction. Furthermore, MAX requires BRG1 to activate neuroendocrine transcriptional programs and to upregulate MYC targets, such as glycolysis-related genes. Finally, inactivation of the MAX dimerization protein, MGA, was also observed in both non-small cell lung cancer and SCLC. Our results provide evidence that an aberrant SWI/SNF-MYC network is essential for lung cancer development. SIGNIFICANCE: We discovered that the MYC-associated factor X gene, MAX, is inactivated in SCLCs. Furthermore, we revealed a preferential toxicity of the inactivation of the chromatin remodeler BRG1 in MAX-deficient lung cancer cells, which opens novel therapeutic possibilities for the treatment of patients with SCLC with MAX-deficient tumors. © 2013 American Association for Cancer Research. Source