Knockdown of LncRNA ANRIL suppresses cell proliferation, metastasis, and invasion via regulating miR-122-5p expression in hepatocellular carcinoma.

OBJECTIVE: Previous studies reported that lncRNA antisense non-coding RNA in the INK4 locus (ANRIL) was upregulated in hepatocellular carcinoma (HCC) tissues and decreased expression of ANRIL could suppress cell proliferation, metastasis, and invasion and induce apoptosis of HCC cells. However, the molecular mechanism of ANRIL involved in HCC tumorigenesis is still unknown.

METHODS: The expressions of ANRIL and miR-122-5p in HCC tissues and cells were quantified by qRT-PCR. MTT assay, colony formation assay, wound healing assay, and transwell invasion assay were performed to evaluate cell growth, metastasis, and invasion, respectively. RNA immunoprecipitation (RIP) assay and luciferase reporter assay were performed to determine whether ANRIL could directly bind to miR-122-5p in HCC cells. Xenograft tumor experiment was conducted to confirm the biological role and underlying mechanism of ANRIL in vivo.

RESULTS: The results showed that ANRIL was upregulated and miR-122-5p was downregulated in HCC tissues and cells. ANRIL was negatively correlated with miR-122-5p expression in HCC tissues. Knockdown of ANRIL or miR-122-5p overexpression suppressed HCC cell viability, colony formation ability, metastasis, and invasion. ANRIL was demonstrated to directly bind to miR-122-5p and inhibit its expression. Forced expression of ANRIL abolished the inhibitory effect of miR-122-5p overexpression on HCC progression. In vivo experiment demonstrated that ANRIL knockdown impeded tumor growth in vivo and increased miR-122-5p expression.

CONCLUSION: Our finding suggested that knockdown of ANRIL suppressed cell proliferation, metastasis and invasion via regulating miR-122-5p expression in HCC, illustrating the underlying mechanism of the oncogenic role of ANRIL in HCC.