Scutellarin induces apoptosis of colorectal cancer HCT116 cells via Hippo signaling pathway

OBJECTIVE To investigate the effect of scutellarin on the apoptosis of human colorectal cancer cells via the Hippo signaling pathway in vitro. METHODS MTT colorimetric method was used to detect the influence of scutellarin on the survival rate of HCT116 cells. And the effect of scutellarin at various concentrations on cell morphology was observed by microscopy. Cell scratch experiment was used to detect the influence of scutellarin on the migration of HCT116 cells. Hoechst33342/PI double staining method was used to detect the effect of scutellarin on the apoptosis of HCT116 cells. Western blotting method was used to assess the action of scutellarin on the expressions of Hippo signaling pathway-related proteins Mst1, Lats1, YAP1, p-YAP(Ser127), TAZ, and its downstream effector proteins c-Myc and cyclin D1, as well as apoptosis-related proteins Bcl-2 and Bax in HCT116 cells. RESULTS Scutellarin significantly affected the morphology of HCT116 cells and reduced the survival rate of HCT116 cells. Hoechst33342/PI double staining showed that scutellarin effectively induced the apoptosis of HCT116 cells. Western blotting analysis showed that the expression levels of Hippo signaling pathway-related proteins Mst1, Lats1, YAP1, TAZ and its downstream effector proteins c-Myc, cyclin D1 were down-regulated in a concentration-dependent manner by scutellarin, and the expression of p-YAP(ser127) was up-regulated. Moreover, scutellarin substantially lessened the expression level of apoptosis-related protein Bcl-2, and promoted the protein level of Bax. CONCLUSION Scutellarin may inhibit the proliferation and migration of HCT116 cells, while induce its apoptosis, potentially by activation of Hippo signaling pathway.