Study on Regulation of Autophagy in Colorectal Cancer SW480 Cells by Ursolic Acid Based on Wnt Signaling Pathway
Objective:To investigate the effect of ursolic acid(UA)on autophagy in colorectal cancer cells and its mechanism of regulation of auto-phagy based on Wnt signaling pathway.Methods:The effect of UA on the proliferation of SW480 cells was detected by MTT assay.In vitro scratch assay was used to measure the effect of UA(5.47,10.94 and 21.88 μmol/L)on the migration of SW480 cells.The influence of UA on autophagosome formation in SW480 cells was observed with MDC/PI assay.The effects of UA on the mRNA levels of autophagy-related genes including microtubule-associated protein light chain3(Lc3),Beclin-1,autophagy-related gene5(Atg5)and P62,and Wnt signaling pathway-related genes involving β-catenin,Tcf4,Gsk-3β,Wnt5a and C-myc were detected by qRT-PCR.Western blot was employed to analyze the influence of UA on the expression of autophagy-related proteins including LC3-Ⅱ,Beclin-1,ATG5 and P62,and Wnt signaling pathway-re-lated proteins involving β-catenin,nuclear β-catenin,TCF4,GSK-3β,p-GSK-3β,Wnt5 A and C-Myc.Results:U A significantly inhibited the proliferation and migration of SW480 cells(P＜0.01),and enhanced the fluorescence intensity of autophagosomes in SW480 cells(P＜0.01).UA significantly up-regulated the mRNA expression levels of Lc3,Beclin-1,Atg5 and Gsk-3β,while down-regulated the mRNA levels of P62,β-catenin,Tcf4,Wnt5a and C-myc in SW480 cells(P＜0.05).Also,UA significantly up-regulated the protein expressions of LC3-Ⅱ,Bec-lin-1,ATG5 and GSK-3β,while down-regulated the protein expressions of P62,β-catenin,nuclear β-catenin,TCF4,Wnt5A,p-GSK-3β(Ser389)and C-Myc in SW480 cells(P＜0.05).The inhibition of UA on the proliferation of SW480 cells was synergized by Wnt signaling in-hibitor IWR-1(P＜0.01),but antagonized by Wnt signaling activator SKL2001(P＜0.01).Conclusion:UA may inhibit the proliferation and migration,and enhance the autophagy of SW480 cells.Its mechanism may be related to decreasing Wnt signaling pathway activity in colorectal cancer cells.
Ursolic acidWnt signaling pathwayAutophagyColorectal cancer
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