Caspase-3 regulates the migration, invasion, and metastasis of colon cancer cells

Caspase-3 (CASP3) is a major mediator of apoptosis activated during cellular exposure to cytotoxic drugs, radiotherapy, or immunotherapy. It is often used as a marker for efficacy of cancer therapy. However, recent reports indicate that caspase-3 also has non-apoptotic roles such as promotion of tumor relapse and tumor angiogenesis. Therefore, the roles of caspase-3 in tumor progression remains to be defined clearly. In this study, we established caspase-3 knockout (KO) colon cancer cell lines by use of the CRISPR technology. In vitro, caspase-3 knockout HCT116 cells were significantly less clonogenic in soft agar assays. They were also significantly less invasive and more sensitive to radiation and mitomycin C than control cells. In vivo, CASP3KO cells formed tumors at rates similar to control cells but were significantly more sensitive to radiotherapy. They were also less prone to pulmonary metastasis when inoculated either subcutaneously or intravenously. At the mechanistic level, caspase-3 gene knockout appeared to cause reduced EMT phenotypes when compared with parental HCT116 cells. Indeed, they showed significantly increased E-cadherin expression, reduced N-cadherin, Snail, Slug, and ZEB1 expression than control cells. Therefore, therapeutic targeting of caspase-3 may not only increase the sensitivity of cancer cell to chemotherapy and radiotherapy, but also inhibit cancer cell invasion and metastases. This article is protected by copyright. All rights reserved.

http://ift.tt/2Hmhe4H