Effect of miR-34b overexpression on the radiosensitivity of non-small cell lung cancer cell lines.

BACKGROUND The miR-34 family, under-expressed in-non small cell lung cancers (NSCLCs), are effectors of p53 activation upon irradiation of cells. We evaluated whether the miR-34b overexpression modulates the NSCLCs response to radiation. MATERIALS AND METHODS NSCLC cell lines A549 with V-KI-RAS2 Kirsten Rat Sarcoma viral oncogene (KRAS) codon 12 mutation and with wild type p53, and H1299, not expressing p53, were irradiated after transfection with pre-miR-34b. Cell survival was assessed by clonogenic survival assays. The apoptosis and the cell cycle were evaluated by flow cytometry. RESULTS In the A549 cell line, overexpression of miR-34b significantly reduced cell survival at lower than 4 Gy radiation doses. There was a significant reduction in B-cell CLL/lymphoma 2 (BCL2) expression but no significant differences were observed in the apoptotic cell population or the cycle profile. No significant effect was recorded in the H1299 irradiated cells. CONCLUSION In the p53 wild type, KRAS mutated NSCLC cells, the overexpression of miR-34b increases radiosensitivity at low doses of radiation.

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

[2]  J. Minna,et al.  A Translational View of the Molecular Pathogenesis of Lung Cancer , 2007, Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer.

[3]  M. Koukourakis,et al.  Radiation-induced autophagy in normal and cancer cells: Towards novel cytoprotection and radio-sensitization policies? , 2009, Autophagy.

[4]  Moshe Oren,et al.  Transcriptional activation of miR-34a contributes to p53-mediated apoptosis. , 2007, Molecular cell.

[5]  Jing Yang,et al.  Identification of Differentially Expressed Genes Contributing to Radioresistance in Lung Cancer Cells using Microarray Analysis , 2005, Radiation research.

[6]  P. Riley.  Free radicals in biology: oxidative stress and the effects of ionizing radiation. , 1994, International journal of radiation biology.

[7]  William C Reinhold,et al.  MicroRNAs modulate the chemosensitivity of tumor cells , 2008, Molecular Cancer Therapeutics.

[8]  Tao Jiang,et al.  The role of microRNA in human lung squamous cell carcinoma. , 2010, Cancer genetics and cytogenetics.

[9]  J Wade Harper,et al.  The DNA damage response: ten years after. , 2007, Molecular cell.

[10]  Wafik S El-Deiry,et al.  P53 and radiation responses , 2003, Oncogene.

[11]  K. Vousden.  Activation of the p53 tumor suppressor protein. , 2002, Biochimica et biophysica acta.

[12]  Michael A. Beer,et al.  Transactivation of miR-34a by p53 broadly influences gene expression and promotes apoptosis. , 2007, Molecular cell.

[13]  D. Beer,et al.  MicroRNA classifiers for predicting prognosis of squamous cell lung cancer. , 2009, Cancer research.

[14]  Yasunori Fujita,et al.  Effects of miR-34a on cell growth and chemoresistance in prostate cancer PC3 cells. , 2008, Biochemical and biophysical research communications.

[15]  R. Stephens,et al.  Unique microRNA molecular profiles in lung cancer diagnosis and prognosis. , 2006, Cancer cell.

[16]  Lesley Seymour,et al.  Role of KRAS and EGFR as biomarkers of response to erlotinib in National Cancer Institute of Canada Clinical Trials Group Study BR.21. , 2008, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[17]  J. Gray,et al.  [19] Cell cycle analysis by flow cytometry , 1979 .

[18]  N. Mailand,et al.  The ATM–Chk2–Cdc25A checkpoint pathway guards against radioresistant DNA synthesis , 2001, Nature.

[19]  Imran Babar,et al.  MicroRNAs as potential agents to alter resistance to cytotoxic anticancer therapy. , 2007, Cancer research.

[20]  Min Zhang,et al.  Restoration of tumor suppressor miR-34 inhibits human p53-mutant gastric cancer tumorspheres , 2008, BMC Cancer.

[21]  Izumi Horikawa,et al.  Nutlin-3a activates p53 to both down-regulate inhibitor of growth 2 and up-regulate mir-34a, mir-34b, and mir-34c expression, and induce senescence. , 2008, Cancer research.

[22]  N. Chen,et al.  Role and regulation of autophagy in cancer. , 2009, Biochimica et biophysica acta.

[23]  J. Soh,et al.  Frequent methylation and oncogenic role of microRNA-34b/c in small-cell lung cancer. , 2012, Lung cancer.

[24]  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.

[25]  B. Vogelstein,et al.  Participation of p53 protein in the cellular response to DNA damage. , 1991, Cancer research.

[26]  George P Cobb,et al.  microRNAs as oncogenes and tumor suppressors. , 2007, Developmental biology.

[27]  H. Matsumoto,et al.  Enhancement of radiosensitivity by topoisomerase II inhibitor, amrubicin and amrubicinol, in human lung adenocarcinoma A549 cells and kinetics of apoptosis and necrosis induction. , 2006, International journal of molecular medicine.

[28]  C. N. Coleman,et al.  Radiation Sensitivity of Human Carcinoma Cells Transfected with Small Interfering RNA Targeted against Cyclooxygenase-2 , 2005, Clinical Cancer Research.

[29]  E. Brambilla,et al.  Pathogenesis of lung cancer signalling pathways: roadmap for therapies , 2009, European Respiratory Journal.

[30]  V. Tarasov,et al.  Differential Regulation of microRNAs by p53 Revealed by Massively Parallel Sequencing: miR-34a is a p53 Target That Induces Apoptosis and G1-arrest , 2007, Cell cycle.