title: Downregulation of miR-7 upregulates Cullin 5 (CUL5) to facilitate G1/S transition in human hepatocellular carcinoma cells.
abstract: MicroRNAs (miRNAs) are small, non-coding RNAs that participate in the regulation of gene expression. In this study, we demonstrate that miR-7 was downregulated in hepatocellular carcinoma (HCC) tissues compared to adjacent non-tumor tissue. Over-expression of miR-7 in QGY-7703 and HepG2 cell lines inhibited colony formation and induced G1/S phase arrest, whereas knockdown of miR-7 produced the opposite phenotype. A tumor suppressor gene, CUL5, was identified as a direct target of miR-7, and CUL-5 is upregulated upon the binding of miR-7 to its 3'UTR. Furthermore, suppression of CUL5 also suppressed cell colony formation and induced cell cycle arrest. Ectopic expression of CUL5 abrogated the effects of miR-7 inhibition on QGY-7703 and HepG2 cell lines. These results indicate that miR-7 suppresses colony formation and causes cell cycle arrest via upregulation of CUL5, and it may function as a tumor suppressor in HCC.
authors: Tianjin Life Science Research Center and Basic Medical School, Tianjin Medical University, Tianjin, China.
authors: Chaoqun
authors: C
authors: Ma
authors: Ying
authors: Y
authors: Qi
authors: Liping
authors: L
authors: Shao
authors: Min
authors: M
authors: Liu
authors: Xin
authors: X
authors: Li
authors: Hua
authors: H
authors: Tang
mesh_terms: D020413:3' Untranslated Regions; D001665:Binding Sites; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D044842:Cullin Proteins / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D059585:G1 Phase Cell Cycle Checkpoints; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference
chemical_list: D020413:3' Untranslated Regions; D044842:Cullin Proteins; D035683:MicroRNAs; C496871:CUL5 protein, human; C549242:MIRN7-1 microRNA, human
keywords: CUL5; cell cycle; hepatocellular carcinoma; miR-7; miRNA