The Endogenous Competing Regulation Among The Alternative Splicing Isoforms Of SMC1A Related To Colorectal Cancer Liver Metastasis

Objective:To study the endogenous competition regulation among the alternative splicing isoforms of SMC1A and the functional differences of different transcripts.Methods:The overexpression vectors of SMC1A transcripts 001 and 201 were respectively synthesized and transfected into wild-type RKO cells.The difference in the metastatic potential was compared by wound healing,transwell assay,and cytokine assay.The overexpression vectors of SMC1A transcripts 002,003,004 and 005 were respectively synthesized and transfected into wild type RKO cells,mutant(SMC1A-201 knocked-out)RKO cells,HCT116 cells,SW480 cells and SW620 cells.After RNA was extracted,effects of overexpression were verified by fluorescence quantitative PCR.After confirming the successful overexpression,RNA was extracted again and the expression of 001 and 201 were detected by fluorescence quantitative PCR.Results:First,the migration distances of the SMC1A-201 over-expressing group and the SMC1A-001 over-expressing group at the 24th and 48th hours were significantly greater than that of control group.The migration ability of SMC1A-201 overexpression group and SMC1A-001 overexpression group was significantly improved,but the migration ability of SMC1A-001 group was higher than that of SMC1A-201 group.The SMC1A-001 overexpression group cells are more capable of secreting SDF-1,IL-6 factors.Second,in wild-type RKO cells,there was no significant difference in the expression of 201 among groups after overexpression of 002,004,005 for 24h and 48h,but the expression of 201 increased significantly after 003 overexpression.In wild-type RKO cells,the expression of 001 increased after 002,003,004,005 transcripts were overexpressed for 48h,and the most significant rise was observed after 003 overexpression.The overexpression of each transcript in the mutant RKO cells,except the 004 overexpression group,was also higher after 48 h than 24 h,and the trend was similar to that in wild-type RKO cells.Third,the overexpression tendency in HCT116 and SW620 cells is different from that in the wild type RKO cells,while the overexpression tendency in SW480 cells is similar to that in the wild type RKO cells.Conclusion:There are functional differences among different transcripts of the SMC1A gene.SMC1A transcript 001 can significantly increase the metastatic potential of tumors,while the potential of SMC1A transcript 201 to promote tumor metastasis is relatively weak.In RKO cells and SW480 cells,overexpression of SMC1A transcript 003 may promote the expression of 201 and 001.