Suppression of hepatocellular carcinoma progression by long noncoding RNA apolipoprotein C1 pseudogene via the regulation of the microRNA-106b-PTEN axis.

Abstract

Numerous researches have reported that long noncoding RNAs (lncRNAs) participate in tumor development and progression. LncRNA apolipoprotein C-I pseudogene 1 (APOC1P1), a pseudogene located in 19q13.2 between apolipoprotein C-I and apolipoprotein C-IV, is involved in a variety of diseases. However, the role of lncRNA APOC1P1 in hepatocellular carcinoma (HCC) remains unknown. Quantitative polymerase chain reaction (qPCR) was performed to examine the expression of APOC1P1, miR-106b, and PTEN (phosphatase and TENsin homolog deleted on chromosome 10) in HCC tissues, adjacent normal tissues, and specific cell lines (LO2, Bel-7407, HCCLM3, MHCC-97H, Hep G2, and Huh-7). Upregulation of APOC1P1 and downregulation of miR-106b were conducted via application of vector transfection and microRNA (miRNA) inhibitor. Bioinformatics analysis and luciferase reporter assay were used to verify the binding sites of APOC1P1, miR-106b, and PTEN. Cell proliferation and invasion were determined with Cell Counting Kit-8 (CCK-8) and Transwell experiments. Subcellular location analysis was used to determine the distribution of APOC1P1 in cells, and Western blotting was used to detect the expression of PTEN. It was found that the expressions of APOC1P1 and PTEN were downregulated, while that of miR-106b was upregulated in HCC tissues and cells. Subcellular location analysis showed that APOC1P1 was localized in cytoplasm and competitively bound to miR-106b. APOC1P1 overexpression and miR-106b inhibition suppressed HCC cell proliferation and invasion. qPCR indicated the negative correlation between APOC1P1 expression and miR-106b expression in HCC tissues and a positive correlation between APOC1P1 and PTEN. Our findings suggested that the lncRNA APOC1P1 inhibits HCC progression by competitively binding to miR-106b, leading to elevated PTEN expression, inhibiting cell proliferation and invasion in HCC cells. These results provide new insights into the diagnosis and therapy of HCC.