Schistosoma mansoni soluble egg antigen suppresses colorectal cancer growth in vitro and in vivo

Abstract

Background: Colorectal cancer (CRC) is the third most common malignant disease around the world. Because the hosts’ immunity plays a great part in regulating tumor cells’ growth and progression, immunotherapies have therefore aroused great interest in treating cancers. Currently, scientists have investigated the use of Schistosomaderived soluble egg antigens (SEA), which is known as a strong immune modulator, in treating a series of immune-related diseases. Methods: In this study, we investigated the anti-tumor effect of SEA against CRC using in vitro cell lines, HCT-116 and DLD-1, as well as in vivo mouse xenograft model. Approaches such as migration assay, invasion assay, and western blotting were done to analyze the anti-tumor effect of SEA. Furthermore, qRT-PCR and ELISA were performed to identify the immune profile of SEA-treated cells as well as SEA-treated xenograft mice. Results: In vitro studies suggested that SEA can dose-dependently inhibit the growth and progression of HCT-116 and DLD-1 cells. This inhibition was accompanied by a reduction of epithelial-mesenchymal transition (EMT), inflammasome inactivation, and apoptosis. SEA also downregulated the expression of IL-4 and IL-10 in the CRC cells, which may be the reason why their growth and progression were suppressed. In vivo studies showed a similar beneficial effect of SEA, as local administration of 25 μg SEA significantly inhibits tumor cell growth. SEA treatment also shifts the host’s immunity from a pro-tumorigenic response to an anti-tumor response. Conclusion: In conclusion, SEA may provide a beneficial effect against CRC, and further investigation may give promise in CRC treatment.