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Micro RNA ‐122 suppresses cell proliferation and induces cell apoptosis in hepatocellular carcinoma by directly targeting Wnt/β ‐catenin pathway
Author(s) -
Xu Jie,
Zhu Xiuming,
Wu Lingjiao,
Yang Rong,
Yang Zeran,
Wang Qiangfeng,
Wu Fusheng
Publication year - 2012
Publication title -
liver international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.873
H-Index - 110
eISSN - 1478-3231
pISSN - 1478-3223
DOI - 10.1111/j.1478-3231.2011.02750.x
Subject(s) - mir 122 , wnt signaling pathway , apoptosis , transfection , cell growth , microbiology and biotechnology , catenin , messenger rna , hepatocellular carcinoma , flow cytometry , chemistry , cell , cancer research , blot , biology , signal transduction , microrna , cell culture , gene , biochemistry , genetics
Aims To validate whether the anti‐cancer effect of micro RNA ‐122 ( miR ‐122) on hepatocellular carcinoma ( HCC ) is mediated through regulating Wnt/β ‐catenin signalling pathways. Methods The expression levels of miR ‐122 in HCC tissues and varied hepatoma cells were quantified by real‐time PCR . MiR‐122 agomir was transfected into HepG2 , Hep3B cells to over‐express miR ‐122. The effect of over‐expression miR ‐122 on proliferation and apoptosis of HepG2 and Hep3B cells was evaluated using CCK ‐8 kit and flow cytometer respectively. The 3′‐ UTR segments of Wnt1 containing the miR ‐122 binding sites were amplified by PCR and the luciferase activity in the transfected cells was assayed. Wnt1 mRNA level was quantified using RT‐PCR . Protein levels of Wnt1 , β‐catenin and TCF ‐4 were detected using W estern blotting. Results In comparison with the expression level of miR ‐122 in para‐cancerous tissues or C hang liver cell, the expression level in HCC tissues or varied hepatoma cells was significantly decreased ( P < 0.05). Over‐expression of miR ‐122 significantly inhibited the proliferation ( P < 0.05), and promoted the apoptosis of HepG2 and Hep3B cells. Over‐expressed miR ‐122 down‐regulated the protein levels of Wnt1 , β‐catenin and TCF ‐4 ( P < 0.05). MiR‐122 suppressed the luciferase activity of the pmiR‐Wnt1‐wt by approximately 50% compared with the negative control, while mutation or removal of the miR ‐122 binding site using si RNA or mir‐122 inhibitor blocked the suppressive effect ( P < 0.05). Conclusions MiR‐122 expression is down‐regulated in human HCC . Over‐expression of miR‐122 inhibits HCC cell growth and promotes the cell apoptosis by affecting Wnt/β‐catenin‐ TCF signalling pathway.