摘要
BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related death worldwide.The 5-year survival rate of patients with early-stage CRC could reach 90%,but it is very low in patients with advanced-stage CRC.Recent studies have shown that circular RNAs play important roles in regulating the migration and invasion of CRC cells.AIM To elucidate the role of circRNA_0084927(circ_0084927)in the migration and invasion of CRC cells and its underlying mechanism.METHODS Clinical tissue samples and cells were collected,and the expression of circ_0084927 was detected by quantitative polymerase chain reaction(qPCR).The diagnostic performance of circ_0084927 was assessed by receiver operating characteristic curve analysis.The role of circ_0084927 in CRC cell proliferation,migration,and invasion was determined using cell counting kit-8 assay,wound healing assay,and transwell assay,respectively.The regulatory relationship among circ_0084927,miRNA-20b-3p(miR-20b-3p),and glutathione S-transferase mu 5(GSTM5)was identified using databases,luciferase reporter assay,qPCR,and Western blot analysis.AKT-mTOR signaling was also verified after circ_0084927 knockdown or miR-20b-3p mimic treatment.RESULTS The expression of circ_0084927 was significantly increased in CRC tissues and cells,and it was higher in advanced-stage CRC compared with early-stage CRC.The area under the curve(AUC)of circ_0084927 was 0.806[95%confidence interval(CI):0.683-0.896].In addition,the AUC was 0.874(95%CI:0.738-0.956)in patients with advanced-stage CRC and 0.713(95%CI:0.555-0.840)in those with early-stage CRC.Knockdown of circ_0084927 inhibited the migration and invasion of HCT116 cells.Moreover,circ_0084927 was found to act as a sponge of miR-20b-3p.MiR-20b-3p activation reduced the circ_0084927 level,whereas miR-20b-3p inhibition increased the circ_0084927 level.But the effect was not found after circ_0084927 mutation.In addition,miR-20b-3p expression in CRC patients was also reduced and negatively correlated with circ_0084927 expression.The function of circ_0084927 in HCT116 cells with circ_0084927 knockdown was rescued by miR-20b-3p.Moreover,GSTM5 expression was significantly decreased after overexpressing miR-20b-3p or inhibiting circ_0084927,but its expression was rescued when circ_0084927 and miR-20b-3p were both inhibited.Finally,AKTmTOR signaling was markedly regulated by circ_0084927 and miR-20b-3p.CONCLUSION The expression of circ_0084927 is significantly increased in CRC and higher in advanced-stage CRC than in early-stage CRC.Moreover,circ_0084927 potentially regulates CRC cell migration and invasion via the miR-20b-3p/GSTM5/AKT/mTOR pathway.
