|microRNA-29a suppresses cell proliferation by targeting SPARC in hepatocellular carcinoma|
Authors: Xu-Chao Zhu, Qiong-Zhu Dong, Xiao-Fei Zhang, Biao Deng, Hu-Liang Jia, Qin-Hai Ye, Lun-Xiu Qin, Xing-Zhong Wu
Affiliations: Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Key Laboratory of Glycoconjugate Research, Ministry of Public Health, Shanghai 200032, P.R. China, Liver Cancer Institute and Zhongshan Hospital, Institutes of Biomedical Sciences, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai 200032, P.R. China
Published online on: Tuesday, September 25, 2012
In the present study, we constructed a lentivirus vector encoding the miR-29a precursor and established two stably infected cell lines, PLC-29a and 97L-29a. The overexpression of miR-29a was confirmed by TaqMan RT-PCR and significantly suppressed the growth of the hepatocellular carcinoma cell lines MHCC-97L and PLC. Dual-luciferase reporter assays indicated that the SPARC mRNA 3'UTR was directly targeted by miR-29a since the mutated 3'UTR was not affected. Silencing SPARC expression by RNAi knockdown resulted in a similar effect as miR-29a overexpression on hepatocellular carcinoma (HCC) cell growth regulation. Anti-miR-29a oligonucleotides (AMOs) upregulated the levels of SPARC in the HCC cells. The phosphorylation of AKT/mTOR downstream of SPARC was inhibited in miR-29a-overexpressing HCC cells. We further examined and compared the expression levels of miR-29a in HCC tissues and the corresponding nearby non-cancerous liver tissues of 110 patients with HCC by qRT-PCR, and significantly lower expression of miR-29a was observed in the tissues affected by HCC. Our findings demonstrate that the expression of miR-29a is important in the regulation of the SPARC-AKT pathway and HCC growth.