title: MicroRNA-21 is overexpressed in renal cell carcinoma.
abstract: OBJECTIVE
  To identify microRNAs (miRNAs) that are overexpressed in renal cell carcinoma (RCC) and characterize the functional role of miR-21.
  
  
  METHODS
  The miRNA expression profiles between RCC tissue and adjacent normal tissue were compared using microarray analysis. The differential expression of miR-21 was validated by real-time polymerase chain reaction (RT-PCR). 786-O RCC cells were transfected with miR-21 mimic, miR-21 inhibitor, or negative controls and cell proliferation, apoptosis and cell cycle were examined by MTT assay and flow cytometry. The expression of programmed cell death 4 (PDCD4) and tropomyosin 1 (TPM1) was detected by RT-PCR and Western blot analysis.
  
  
  RESULTS
  Compared to adjacent normal tissue, 10 human miRNAs were significantly upregulated and 7 were downregulated in RCC tissue. RT-PCR confirmed that miR-21 was significantly overexpressed in RCC tissue. In vitro expression of miR-21 mimic promoted the growth of 786-O cells, whereas miR-21 inhibitor inhibited cell growth by inducing apoptosis and cell cycle arrest at S phase. Furthermore, miR-21 mimic or inhibitor significantly reduced or increased the expression of PDCD4 and TPM1.
  
  
  CONCLUSIONS
  MiR-21 is overexpressed in RCC tissue and modulates the growth, apoptosis and cell cycle progression of RCC cells and regulates the expression of PDCD4 and TPM1.
authors.affiliation: Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Lv
authors.forename: Fengxian
authors.initials: F
authors.lastname: Huang
authors.forename: Haiping
authors.initials: H
authors.lastname: Mao
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.forename: Man
authors.initials: M
authors.lastname: Yang
authors.forename: Xueqing
authors.initials: X
authors.lastname: Yu
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D059447:Cell Cycle Checkpoints / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000096:biosynthesis; D014335:Tropomyosin / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: D051017:Apoptosis Regulatory Proteins; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins; C490775:TPM1 protein, human; D014335:Tropomyosin