Circular RNA ARHGAP26 is over-expressed and its downregulation inhibits cell proliferation and promotes cell apoptosis in gastric cancer cells.

Background/Aims: This study aimed to explore the effect of circular RNA ARHGAP26 (circ-ARHGAP26) on cell proliferation and apoptosis in gastric cancer (GC) cell lines. Materials and Methods: Human GC cell lines including HGC-27, AGS, SGC-7901, BGC-823, NCI-N87 and human normal gastric mucosal cells GSE-1 were cultured. The circ-ARHGAP26 expression was determined by quantitative polymerase chain reaction assay. Blank inhibitor and circ-ARHGAP26 inhibitor plasmids were transfected into HGC-27 or AGS cells as NC (-) and circ-ARHGAP26(-) groups. Counting Kit-8 (CCK-8) and Annexin V (AV)/propidium iodide (PI) were conducted to evaluate cell proliferation and cell apoptosis, respectively. Western blot was performed to determine the expressions of apoptotic markers (C-Caspase3 and Bcl-2). Results: The circ-ARHGAP26 expression was elevated in HGC-27 (P < 0.001), AGS (P < 0.001), SGC-7901 (P < 0.01), BGC-823 (P < 0.05) and NCI-N87 (P < 0.05) GC cell lines compared to GSE-1 cells. In HGC-27 cells, CCK8 assay revealed that cell proliferation was decreased at 48 h (P < 0.05) and 72 h (P < 0.01), while AV/Pl assay disclosed that cell apoptosis rate was increased at 72 h in circ-ARHGAP26 (-) group compared to NC (-) group (P < 0.01). Western blot assay also illuminated that apoptotic marker C-Caspase 3 was raised, while anti-apoptotic marker Bcl-2 was reduced at 72 h in circ-ARHGAP26 (-) group compared to NC (-) group. In addition, further validation in AGS cells also exhibited that cells proliferation was repressed, while apoptosis was enhanced in circ-ARHGAP26 (-) group compared to NC (-) group. Conclusion: The circ-ARHGAP26 is over-expressed and its downregulation inhibits cell proliferation and promotes cells apoptosis in GC cells.