title: Effect of miR-34b overexpression on the radiosensitivity of non-small cell lung cancer cell lines.
abstract: 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.
  
  
  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.
  
  
  CONCLUSIONS
  In the p53 wild type, KRAS mutated NSCLC cells, the overexpression of miR-34b increases radiosensitivity at low doses of radiation.
authors.affiliation: Applied Molecular Biology/Biochemistry Unit, FMUC, Coimbra, Portugal. joanabalca.silva@gmail.com
authors.forename: Joana
authors.initials: J
authors.lastname: Balça-Silva
authors.forename: Sílvia
authors.initials: S
authors.lastname: Sousa Neves
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Gonçalves
authors.forename: Ana Margarida
authors.initials: AM
authors.lastname: Abrantes
authors.forename: João
authors.initials: J
authors.lastname: Casalta-Lopes
authors.forename: Maria Filomena
authors.initials: MF
authors.lastname: Botelho
authors.forename: Ana Bela
authors.initials: AB
authors.lastname: Sarmento-Ribeiro
authors.forename: Henriqueta Coimbra
authors.initials: HC
authors.lastname: Silva
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D035683:MicroRNAs / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D016283:Proto-Oncogene Proteins p21(ras); D011836:Radiation Tolerance; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D018631:ras Proteins / Q000235:genetics
chemical_list: C117307:KRAS protein, human; C522425:MIRN34 microRNA, human; D035683:MicroRNAs; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins