Epigenetic Silencing of MicroRNA-34b/c Plays an Important Role in the Pathogenesis of Malignant Pleural Mesothelioma

Purpose: Malignant pleural mesothelioma (MPM) is an aggressive tumor with a dismal prognosis. Unlike other malignancies, TP53 mutations are rare in MPM. Recent studies have showed that altered expression of microRNA (miRNA) is observed in human malignant tumors. In this study, we investigated the alterations of miR-34s, a direct transcriptional target of TP53, and the role of miR-34s on the pathogenesis of MPM. Experimental Design: Aberrant methylation and expression of miR-34s were examined in MPM cell lines and tumors. miR-34b/c was transfected to MPM cells to estimate the protein expression, cell proliferation, invasion, and cell cycle. Results: Aberrant methylation was present in 2 (33.3%) of 6 MPM cell lines and 13 (27.7%) of 47 tumors in miR-34a and in all 6 MPM cell lines (100%) and 40 (85.1%) of 47 tumors in miR-34b/c. Expression of miR-34a and 34b/c in all methylated cell lines was reduced and restored with 5-aza-2′-deoxycytidine treatment. Because epigenetic silencing was the major event in miR-34b/c, we investigated the functional role of miR-34b/c in MPM. miR-34b/c–transfected MPM cells with physiologic miR-34b/c expression exhibited antiproliferation with G1 cell cycle arrest and suppression of migration, invasion, and motility. The forced overexpression of miR-34b/c, but not p53, showed a significant antitumor effect with the induction of apoptosis in MPM cells. Conclusions: We show that the epigenetic silencing of miR-34b/c by methylation is a crucial alteration and plays an important role in the tumorigenesis of MPM, suggesting potential therapeutic options for MPM. Clin Cancer Res; 17(15); 4965–74. ©2011 AACR.

[1]  F. Favero,et al.  MicroRNA signature of malignant mesothelioma with potential diagnostic and prognostic implications. , 2010, American journal of respiratory cell and molecular biology.

[2]  R. Aharonov,et al.  Molecular and Cellular Pathobiology Cancer Research hsa-miR-29 c * Is Linked to the Prognosis of Malignant Pleural Mesothelioma , 2010 .

[3]  Min Zhang,et al.  MicroRNA miR-34 Inhibits Human Pancreatic Cancer Tumor-Initiating Cells , 2009, PloS one.

[4]  C. Croce,et al.  MicroRNAs in Cancer. , 2009, Annual review of medicine.

[5]  A. Nicholson,et al.  CDKN2A, NF2, and JUN are dysregulated among other genes by miRNAs in malignant mesothelioma—A miRNA microarray analysis , 2009, Genes, chromosomes & cancer.

[6]  C. Croce,et al.  SnapShot: MicroRNAs in Cancer , 2009, Cell.

[7]  Michael Peyton,et al.  Alterations in Genes of the EGFR Signaling Pathway and Their Relationship to EGFR Tyrosine Kinase Inhibitor Sensitivity in Lung Cancer Cell Lines , 2009, PloS one.

[8]  Carola Berking,et al.  Inactivation of miR-34a by aberrant CpG methylation in multiple types of cancer , 2008, Cell cycle.

[9]  M. Toyota,et al.  Epigenetic silencing of microRNA-34b/c and B-cell translocation gene 4 is associated with CpG island methylation in colorectal cancer. , 2008, Cancer research.

[10]  Y. Sekido.  Molecular biology of malignant mesothelioma , 2008, Environmental health and preventive medicine.

[11]  S. Toyooka,et al.  Advances in the molecular biology of malignant mesothelioma. , 2008, Acta medica Okayama.

[12]  H. Hermeking.  p53 enters the microRNA world. , 2007, Cancer cell.

[13]  Wei Wang,et al.  MicroRNA-34b and MicroRNA-34c are targets of p53 and cooperate in control of cell proliferation and adhesion-independent growth. , 2007, Cancer research.

[14]  L. Lim,et al.  A microRNA component of the p53 tumour suppressor network , 2007, Nature.

[15]  M. Fraga,et al.  Genetic unmasking of an epigenetically silenced microRNA in human cancer cells. , 2007, Cancer research.

[16]  C. Croce,et al.  MicroRNA signatures in human cancers , 2006, Nature Reviews Cancer.

[17]  R. Stahel,et al.  p53-induced apoptosis occurs in the absence of p14(ARF) in malignant pleural mesothelioma. , 2006, Neoplasia.

[18]  Peter A. Jones,et al.  Specific activation of microRNA-127 with downregulation of the proto-oncogene BCL6 by chromatin-modifying drugs in human cancer cells. , 2006, Cancer cell.

[19]  Jennifer Taylor,et al.  Polycistronic RNA polymerase II expression vectors for RNA interference based on BIC/miR-155 , 2006, Nucleic acids research.

[20]  M. Lind,et al.  Expression of Bcl-2 Family Members in Malignant Pleural Mesothelioma , 2006, Acta oncologica.

[21]  S. Elledge,et al.  A lentiviral microRNA-based system for single-copy polymerase II-regulated RNA interference in mammalian cells. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[22]  B. Aggarwal,et al.  Molecular Targets and Anticancer Potential of Indole-3-Carbinol and Its Derivatives , 2005, Cell cycle.

[23]  H. Horvitz,et al.  MicroRNA expression profiles classify human cancers , 2005, Nature.

[24]  David J Sugarbaker,et al.  Tumorigenesis and Neoplastic Progression Identification of Novel Candidate Oncogenes and Tumor Suppressors in Malignant Pleural Mesothelioma Using Large-Scale Transcriptional Profiling , 2005 .

[25]  J. Pollack,et al.  Immortalization of Human Bronchial Epithelial Cells in the Absence of Viral Oncoproteins , 2004, Cancer Research.

[26]  D. Bartel.  MicroRNAs Genomics, Biogenesis, Mechanism, and Function , 2004, Cell.

[27]  M. Oren,et al.  Decision making by p53: life, death and cancer , 2003, Cell Death and Differentiation.

[28]  J. Minna,et al.  Aberrant methylation and simian virus 40 tag sequences in malignant mesothelioma. , 2001, Cancer research.

[29]  S. Jhanwar,et al.  Expression of GPC3, an X-linked recessive overgrowth gene, is silenced in malignant mesothelioma , 2000, Oncogene.

[30]  Y. Soini,et al.  Apoptosis and expression of apoptosis regulating proteins bcl-2, mcl-1, bcl-X, and bax in malignant mesothelioma. , 1999, Clinical cancer research : an official journal of the American Association for Cancer Research.

[31]  T. H. van der Kwast,et al.  The gene for the cyclin‐dependent‐kinase‐4 inhibitor, CDKN2A, is preferentially deleted in malignant mesothelioma , 1998, International journal of cancer.

[32]  J. Herman,et al.  Methylation-specific PCR: a novel PCR assay for methylation status of CpG islands. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[33]  D. Fisher,et al.  p53 in life and death. , 1996, Clinical cancer research : an official journal of the American Association for Cancer Research.

[34]  J. Herman,et al.  5′ CpG island methylation is associated with transcriptional silencing of the tumour suppressor p16/CDKN2/MTS1 in human cancers , 1995, Nature Medicine.

[35]  J. Benichou,et al.  Malignant mesothelioma: attributable risk of asbestos exposure. , 1994, Occupational and environmental medicine.

[36]  R. Metcalf,et al.  p53 and Kirsten-ras mutations in human mesothelioma cell lines. , 1992, Cancer research.

[37]  S. Jhanwar,et al.  Genetic alterations of the p53 gene are a feature of malignant mesotheliomas. , 1991, Cancer research.

[38]  B. Vogelstein,et al.  p53 mutations in human cancers. , 1991, Science.

[39]  R. Kratzke,et al.  Inhibition of both mesothelioma cell growth and Cdk4 activity following treatment with a TATp16INK4a peptide. , 2008, Anticancer research.

[40]  G. Gordon,et al.  Functional analysis of c-Met/hepatocyte growth factor pathway in malignant pleural mesothelioma. , 2006, Cancer research.

[41]  J. Roth,et al.  Adenovirus-mediated Bak gene transfer induces apoptosis in mesothelioma cell lines. , 2001, The Journal of thoracic and cardiovascular surgery.

[42]  K. Kinzler,et al.  A simplified system for generating recombinant adenoviruses. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[43]  J Espinosa Arranz,et al.  [Malignant mesothelioma]. , 1994, Medicina clinica.