Study on the the mechanism of circ_0061140 regulating the proliferation, cycle distribution and apoptosis of gastric cancer cells by targeting miR-548b-3p

Objective To investigate the expression levels of circ_0061140 and miR-548b-3p in gastric cancer cells, and explore the effects of circ_0061140 on the proliferation, cycle distribution and apoptosis of gastric cancer cells by targeting miR-548b-3p.

Methods The relative levels of circ_0061140 and miR-548b-3p in human gastric mucosal cells GES1 and gastric cancer cell lines(SNU-1, AGS, HS-746T) were detected using the RT-qPCR.The small interfering RNA of circ_0061140, miR-548b-3p mimic, and small interfering RNA of circ_0061140 + miR-548b-3p inhibitor were transfected into SNU-1 cells, respectively.The viability of SNU-1 cells was detected by CCK-8 assay, the apoptosis and cycle distribution were detected by flow cytometry.The dual luciferase reporter experiment, RIP assay and RT-qPCR were used to analyze the target regulation relationship between circ_0061140 and miR-548b-3p.

Results Compared with GES1 cells, the relative level of circ_0061140 in SNU-1, AGS and HS-746T cells significantly increased(P < 0.05), and the relative level of miR-548b-3p significantly decreased(P < 0.05 to P < 0.01).After interfering the expression of circ_0061140, the cell viability and S phase ratio of SNU-1 cells were significantly reduced(P < 0.05 to P < 0.01), and the apoptosis rate, G0/G1 phase ratio, and relative levels of miR-548b-3p significantly increased(P < 0.05 to P < 0.01).After overexpression of miR-548b-3p, the cell viability and S phase ratio of SNU-1 cells were significantly reduced(P < 0.01), and the apoptosis rate and G0/G1 phase ratio significantly increased(P < 0.01).The relative level of miR-548b-3p in SNU-1 cells was significantly reduced after overexpression of circ_0061140(P < 0.05).The circ_0061140 was directly and specifically bound to miR-548b-3p.Inhibiting the miR-548b-3p expression could significantly reduce the effects of interfering circ_0061140 on the cell viability, cycle distribution and apoptosis of SNU-1 cells(P < 0.01).

Conclusions The circ_0061140 expression is up-regulated, and the miR-548b-3p expression is down-regulated in gastric cancer cells.Interfering circ_0061140 can suppress the cell proliferation of gastric cancer cells by up-regulating miR-548b-3p, induce cell arrest in G0/G1 phase, and promote apoptos.