title: Effect of MicroRNA-218 on the viability, apoptosis and invasion of renal cell carcinoma cells under hypoxia by targeted downregulation of CXCR7 expression.
abstract: OBJECTIVE
  To investigate the effect of microRNA-218 on the viability, apoptosis and invasion of renal cell carcinoma cells under hypoxia by targeted regulation of expression of chemokine receptor 7 (CXCR7).
  
  
  METHODS
  The expression of miR-218 in renal cell carcinoma cell lines under normal and hypoxia conditions, as well in normal renal tubular epithelial cells (HK2) was measured using RT-PCR. MiR-218 mimic and NC were transfected into renal cell carcinoma cell line ACHN using Lipofectamine™ 2000. The expression of miR-218 was analyzed using RT-PCR. The viability, apoptosis, migration and invasion of the transfected cells were assayed using the MTT assay, flow cytometry and transwell assays. The expression of CXCR7 was assayed using RT-PCR and Western blot. Luciferase reporter was used to verify the downstream target of miR-218.
  
  
  RESULTS
  The expression of miR-218 was lower than in renal cell carcinoma cell lines ACHN, 769-p and Caki-1 that in HK-2. The expression of miR-218 in the renal carcinoma cell lines was lower under hypoxia than under normal oxygen conditions. The expression of miR-218 in ACHN cells under normal and hypoxic conditions was significantly increased after transfection with miR-218 mimic. Compared with NC transfected cells under normal oxygen condition, the mimic-transfected cells had reduced viability, migration ability and invasion ability, and increased apoptosis, and mimic transfected-cells under hypoxia had significantly reduced viability, migration ability and invasion ability, and increased apoptosis. Overexpression of miR-218 mimic resulted in significant reduction in the expression of CXCR7 at protein and mRNA levels under normal and hypoxic conditions. Luciferase reporter assay confirmed that CXCR7 is the target protein of miR-218.
  
  
  CONCLUSIONS
  Up-regulation of miR-218 expression in renal cell carcinoma under hypoxia can result in significant and targeted down-regulation of CXCR7 expression, which could reduce cell viability, migration and invasion ability and induce apoptosis in the cancer cells.
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China; Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang, Jiangxi 330006, China.
authors.forename: Shouhua
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Urology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China.
authors.forename: Zhengdong
authors.initials: Z
authors.lastname: Hong
authors.affiliation: Department of Urology, The First People's Hospital of Fuzhou, Fuzhou, Jiangxi 344000, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang, Jiangxi 330006, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lei
authors.affiliation: Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang, Jiangxi 330006, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China. Electronic address: quelingliu607@sina.com.
authors.forename: Queling
authors.initials: Q
authors.lastname: Liu
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000473:pathology*; D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D017930:Genes, Reporter; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000473:pathology; D008156:Luciferases / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D010100:Oxygen / Q000494:pharmacology; D054387:Receptors, CXCR / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
chemical_list: C501896:ACKR3 protein, human; C547471:MIRN218 microRNA, human; D035683:MicroRNAs; D054387:Receptors, CXCR; D008156:Luciferases; D010100:Oxygen
keywords: Chemokine receptor 7; Renal cell carcinoma; miR-218