Conclusion
Our results demonstrate that CTP markedly inhibits tumor growth and activates a protective role of YAP in colorectal cancer cells, indicating that combination of CTP and YAP targeting drugs may be a promising strategy for colorectal cancer treatment.
Methods
Cell viability and cell proliferation were detected by MTT and BrdU assay. Western blotting and immunofluorescence were performed to determine CTP-induced YAP dephosphorylation and nuclear localization. Western blotting, siRNA transfection and RT-PCR analysis were carried out to investigate the mechanisms of CTP-mediated YAP activation. The anti-tumor activities of CTP were observed in mice tumor models.
Results
We demonstrated that CTP inhibits the proliferation of colorectal cancer cells both in vitro and in vivo. Moreover, we showed that CTP activates YAP in colorectal cancer cells. Mechanistically, CTP promotes LATS1 degradation via the ubiquitination/proteasome pathway, resulting in YAP dephosphorylation and nuclear localization, leading to induce YAP target genes expression in colorectal cancer cells. Inhibition of YAP activity enhances CTP-mediated inhibition of cell proliferation, suggesting that YAP plays a protective role in CTP-induced antiproliferative effect.