Abstract

Purpose: Colorectal cancer is a lethal and prevalent type of cancer in both men and women worldwide, which can develop resistance to cancer chemotherapy. Developing an effective therapeutic agent is the most promising method for this life-threatening disease. The present study aimed to identify, clone, express and purify the recombinant arazyme (r-arazyme) of Serratia proteomaculans and evaluate the antitumor effect of r-arazyme in vitro. Methods: Bacterial strains and cell line, construction of expression vector and preparation of recombinant protein were prepared and then evaluated by western blot, cell culture, cell viability assay, lactate dehydrogenase release assay, cell apoptosis assay, caspase-3 and -9 activation assay, adhesion assay, matrigel invasion assay and reverse transcriptase-polymerase chain reaction (RT-PCR). Results: R-arazyme caused a great cytotoxic effect against human colorectal adenocarcinoma (HT29) cells in a dose-dependent manner, without any cytotoxic effect on human embryonic kidney cells 293 (HEK 293). In addition, r-arazyme could induce apoptosis in colorectal cancer cell lines via caspase-3 activation and the elevation of the Bax/Bcl-2 ratio. Further, r-arazyme inhibited cancer cells angiogenesis by significantly reducing the expression of angiogenesis-related genes such as VEGF, VEGFR-1, and VEGFR-2. Furthermore, r-arazyme could prevent invasion and adhesion of cancer cells. In general, the results may support the evidence that r-arazyme is a promising therapeutic candidate against cancer. Conclusion: R-arazyme may play an important role in developing effective therapies against colorectal adenocarcinoma in humans, which results in reducing the overall morbidity and mortality related to colorectal cancer.