Circ_0000105 promotes liver cancer by regulating miR-498/PIK3R1.

Abstract

A growing number of studies demonstrate that circular RNA (circRNA) has a prominent role in the regulation of numerous biological behaviors of tumor cells. The present study aimed to investigate the expression, function and molecular mechanisms of circ_0000105 in liver cancer. A quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to obtain the expressions of circ_0000105 and miR-498 in liver cancer tissues and cells. The association between the expression level of circ_0000105 and the clinicopathological characteristics of liver cancer patients was analyzed. qRT-PCR and western blotting were utilized to investigate the expression of phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) in cells. Cell counting kit-8, bromodeoxyuridine and flow cytometry assays were utilized to determine liver cancer cell proliferation and apoptosis, respectively. Bioinformatics, a luciferase reporter gene experiment and a RNA immunoprecipitation experiment were conducted to predict and confirm the targeting correlation of circ_0000105 and miR-498, as well as miR-498 and PIK3R1. Circ_0000105 was highly expressed in liver cancer tissues and cell lines. Moreover, its high expression was associated with an increase in the T stage of liver cancer patients and a low degree of tumor differentiation. Circ_0000105 overexpression promoted liver cancer cell proliferation and inhibited apoptosis, whereas knocking down circ_0000105 triggered the opposite effect. miR-498 was a downstream target of circ_0000105, inhibiting liver cancer cell proliferation and promoting apoptosis. Mechanistically, circ_0000105 indirectly up-regulated the expression of PIK3R1 by adsorbing miR-498. Circ_0000105 plays a cancer-promoting role in liver cancer by regulating the miR-498/PIK3R1 axis.