title: [Overexpression of miR-21 promotes proliferation and reduces apoptosis in non-small cell lung cancer].
abstract: OBJECTIVE
  To elucidate the regulatory mechanism underlying proliferation and anti-apoptosis in NSCLC by overexpression of miR-21.
  
  
  METHODS
  Real-time PCR was used to measure miR-21 abundance in non-small cell lung cancer (NSCLC) tumor samples and adjacent normal tissues, as well as NSCLC cell lines. Tumor suppressor genes as potential targets of miR-21 were predicted by sequence analysis. Luciferase assay and Western blot were used to assess the regulatory effect. The effect on A549 cell viability and apoptosis by miR-21-induced gene repression was tested by trypan-blue exclusion and flow cytometry.
  
  
  RESULTS
  miR-21 expression was 2.24-fold higher in the NSCLC tumor samples and 3.06-fold higher in the A549 cells than that in the adjacent normal tissues. Sequence prediction and gene expression regulation assays showed that miR-21 could reversely regulate the expression of PDCD4 (P < 0.01). Suppression of miR-21 expression is associated with an elevation of Pdcd4, resulting in a significant reduction of proliferation and the apoptosis rate (2.6%) was increased to 10.9%. Moreover, the anti-proliferation and pro-apoptotic effect by miR-21 suppression could be reversed by PDCD4 knock down.
  
  
  CONCLUSIONS
  Suppression of the tumor suppressor PDCD4 expression may be one of the important regulatory pathways of the miR-21-mediated cell proliferation and decrease of apoptosis in non-small cell lung cancer.
authors.affiliation: Department of Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Lan
authors.forename: Cong-yao
authors.initials: CY
authors.lastname: Lin
authors.forename: Hong-yin
authors.initials: HY
authors.lastname: Yuan
authors.forename: Bin
authors.initials: B
authors.lastname: Xiong
mesh_terms: D000368:Aged; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D016376:Oligonucleotides, Antisense / Q000235:genetics; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D051017:Apoptosis Regulatory Proteins; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins