Let-7c inhibits metastatic ability of mouse hepatocarcinoma cells via targeting mannoside acetylglucosaminyltransferase 4 isoenzyme A

Aberrant glycosylation may promote tumor invasion and metastasis. To investigate whether microRNA (miRNA) is involved in glycosylation-related metastasis, we examined the role of let-7c, a well-known tumor-suppressor miRNA, in glycosylation in murine hepatocarcinoma cell lines Hca-F and Hca-P. We found that let-7c level was higher in Hca-P cells (with lower lymphatic metastasis potential) than in Hca-F cells (with higher lymphatic metastasis potential). Overexpression of let-7c decreased hyper-N-glycosylation of Hca-F cells and repressed their metastatic and invasive ability. Mannoside acetylglucosaminyltransferase 4, isoenzyme A (Mgat4a) is a key glycosyltransferase in the pathway of synthesizing complex N-glycans. Bioinformatics analysis indicates that Mgat4a may be a target of let-7c, which has been verified by dual-luciferase reporter gene assay. Furthermore, the anti-metastatic effect of overexpressed let-7c is similar to that of Mgat4a siRNAs transfection. Hence, our results suggest that let-7c may inhibit the metastatic ability of Hca-F cells, at least partially, via repressing Mgat4a activity.