Effects of serine-hydroxymethyltransferase 2 on cell proliferation of skin cutaneous melanoma cells
Objective To investigate the effect and its mechanism of serine hydroxymethyltransferase 2(SHMT2)on the cell prolifera-tion of skin cutaneous melanoma cell lines A-375.Methods The expression of SHMT2 in human skin cutaneous melanoma and its correlation with β-catenin,c-Myc and Cyclin D1 were analyzed based on GEPIA online database.The human skin cutaneous melanoma cell line A-375-SHMT2 stably overexpressing SHMT2 was screened by puromycin.Cell proliferation and cell cycle were detected by cell growth curve,CCK-8 assay and flow cytometry.The protein levels of β-catenin,Cyclin D1 and c-Myc were detected by Western blot.The activity of wnt/β-catenin signaling pathway was detected by TOP/FOP-Flash luciferase reporter assay.After XAV-939 was used to inhibit wnt/β-catenin signaling pathway activity in A-375-SHMT2 cells,the change of cell proliferation was observed.Results The results of GEPIA online database analysis showed that SHMT2 was highly expressed in human cutaneous melanoma tissues(P<0.05),and that SHMT2 expression was positively correlated with β-catenin,c-Myc and Cyclin D1(P<0.05).The A-375-SHMT2 cell line with stable SHMT2 expression and the control cell line A-375-GFP were successfully obtained.The proliferation ability of A-375-SHMT2 cells was significantly higher than that of A-375-GFP cells(P<0.05),and the proportion of A-375-SHMT2 cells in the G0/G1 phase was lower than that of A-375-GFP cells(P<0.05),while the proportion of S and G2/M phase cells was higher(P<0.05).Western blot and TOP/FOP assay showed that SHMT2 enhanced wnt/β-catenin signaling pathway activity and upregulated the expressions of β-catenin,c-Myc and Cyclin D1(allP<0.05).The promoted cell growth and the upregulated expressions of Cyclin D1 and c-Myc induced by SHMT2 in A-375-SHMT2 cells were reversed by XAV-939.Conclusion SHMT2 can promote the proliferation of human cutaneous melanoma cells in vitro by activating wnt/β-catenin signaling pathway activity.