title: MiRNA-21: a biomarker predictive for platinum-based adjuvant chemotherapy response in patients with non-small cell lung cancer.
abstract: OBJECTIVE
  To investigate the possible role of microRNAs in the resistance to platinum based chemotherapy in non-small cell lung cancer (NSCLC), explore their potential role and find potential biomarkers for prediction of the response to platinum.
  
  
  RESULTS
  21 miRNAs were deregulated in A549/CDDP. Increased miR-21 expression significantly increased the resistance of A549 cell to platinum, whereas reduced miR-21 decreased the resistance of A549/CDDP cell. This finding was further validated in the tissue samples of 58 patients and it was found that miR-21 expression was significantly increased in platinum based chemotherapy-resistant patients (n = 58, p = 0.000). And increased miR-21 expression was associated with the shorter DFS (p = 0.008). Among these 58 patients, 32 had the corresponding plasma samples and similar tendencies were detected in 68.75% patients. Finally, transfection of A549/CDDP with anti-miR-21 increased the expression of PTEN and decreased Bcl-2. In contrast, pre-miR-21 decreased the expression of PTEN and increased Bcl-2 in A549.
  
  
  METHODS
  Microarray was employed to compare the expression of miRNAs between A549 and A549/CDDP cells. The effect of a differently expressed miRNA (miR-21) was examined on the sensitivity of cells to platinum. MiR-21 expression in NSCLC tumor tissues and matched plasma sample was also analyzed by Real-time PCR.
  
  
  CONCLUSIONS
  Our data suggests that the expression level of miR-21 in tumor tissue and plasma might be used as a biomarker to predict adjuvant platinum based chemotherapy response and disease free survival in patients with NSCLC. Thus, it may serve as a novel therapeutic target to modulate platinum-based chemotherapy.
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China. Yoghurt831030@126.com
authors.forename: Wen
authors.initials: W
authors.lastname: Gao
authors.forename: Xiao
authors.initials: X
authors.lastname: Lu
authors.forename: Lingxiang
authors.initials: L
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Dongjie
authors.initials: D
authors.lastname: Feng
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Shu
mesh_terms: D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D019008:Drug Resistance, Neoplasm; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D009944:Organoplatinum Compounds / Q000494:pharmacology*
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D009944:Organoplatinum Compounds