Overexpression of microRNA-30a-5p inhibits liver cancer cell proliferation and induces apoptosis by targeting MTDH/PTEN/AKT pathway
Increasing results suggest microRNAs (miRNAs) could function important roles in malignant tumor progression. miR-30a-5p is downregulated in variety of cancers and acts as a cancer suppressing gene. The functions and molecular mechanisms of miRNA-30a-5p in hepatocellular carcinoma (HCC) remain unclear. In the present study, quantitative real-time PCR (qRT–PCR) was used to detect miR-30a-5p expression in 16 pairs of HCC and their adjacent non-cancerous tissues and HCC cell lines. By overexpression of miRNA-30a-5p, CCK-8 and colon formation assay were used to evaluate cell growth and flow cytometry to evaluate cell apoptosis. Western blot was used to test protein expression. And potential mechanisms were analyzed with luciferase activity assay. In vivo HepG2 tumor growth was observed with nude mice. Our results showed that miR-30a-5p expression in HCC tissues was significantly lower compared to adjacent non-cancerous liver tissues, and lower miR-30a-5p expression was also observed in HCC cell lines compared to normal liver cell. Luciferase assay showed that metadherin (MTDH) mRNA was a direct target of miR-30a-5p. A significant reverse correlation between miR-30a-5p and MTDH in liver cancer tissues was observed. miR-30a-5p overexpression in HCC cells significantly inhibited cell proliferation, colon formation, and induced apoptosis while MTDH overexpression reversed growth inhibition and apoptosis induction of miRNA-30a-5p in HCC cells. miRNA-30a-5p upregulated phosphatase and tensin homolog (PTEN) protein expression and thus inhibited AKT activating by targeting MTDH. miRNA-30a-5p also significantly inhibited HepG2 tumor growth in vivo. Our results suggest that underexpression of miR-30a-5p might function as a tumor suppressing miRNA by directly targeting MTDH in HCC and is therefore a potential candidate biomarker for HCC targeting therapy.
KeywordsHepatocellular carcinoma miR-30a-5p Proliferation Apoptosis Metadherin
This research was funded by the National Natural Science Foundation of China, projects No: 81272570, and the Health Bureau of Chongqing City, projects No: 2012-1-035.
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Conflicts of interest
Human and animal rights and informed consent
In this study, written informed consent was obtained from all patients, and the Chinese Medical Association Society of Medicine’s Ethics Committee approved all aspects of this study in accordance with the Helsinki Declaration. All experimental procedures were conducted in accordance with the Guide for the Care and Use of Laboratory Animals and approved by our institutional ethical guidelines for animal experiments.