Study on Anti Tumor Mechanism of Piperine Based on Wnt/β-catenin Signal

OBJECTIVE To study the mechanism of piperine at low dose regulating the proliferation and invasion abilities of gastric cancer HGC-27 cells by down-regulating the expression of Wnt/β-catenin signaling molecules. METHODS HGC-27 cells were cultured in vitro and exposed to gradient concentration of piperine. The cell viability after 24 h was measured by CCK-8 assay, and apoptotic rate was analyzed by flow cytometry. The cells were divided into normal group(HGC-27 cell), control group(Wnt/β-catenin inhibitor group) and experimental group(low dose piperine). CCK-8 assay was used to detect cell viability after 12, 24, 48 h. BrdU labeled flow cytometry was used to detect cell proliferation rate, the cell migration ability was detected by scratch test, the cell invasion ability was detected by Transwell assay. The protein expression of Wnt/β-catenin and the matrix metalloproteinases MMP2, MMP9 and cadherin N-cadherin were determined by Western blot. The mRNA expression of β-catenin, MMP2, MMP9 and N-cadherin was detected by RT-qPCR. RESULTS Compared with normal group, piperine at 5 μmol·L^-1 inhibited cell proliferation without obvious cytotoxicity, time-dependently reduced the proliferation of HGC-27 cells with statistical significant(P<0.05). The results of scratch test and Transwell experiment showed that piperine at 5 μmol·L^-1reduced the migration and invasion abilities of the HGC-27 cells as compared with normal group(P<0.05). Piperine significantly reduced the expression of Wnt/β-catenin signaling molecules, as well as the protein levels of MMP2, MMP9 and N-cadherin as compared with normal group(P<0.05). RT-qPCR results showed that the mRNA expression levels of β-catenin, MMP2, MMP9 and N-cadherin were significantly lower than those in normal group(P<0.05). CONCLUSION Piperine at low dose can regulate the proliferation and invasion of gastric cancer HGC-27 cells by down-regulating the expression of Wnt/β-catenin signaling molecules, which may be one of the anti-tumor mechanisms of piperine.