Preventive intervention with Agaricus blazei murill polysaccharide exerts anti-tumor immune effect on intraperitoneal metastasis colorectal cancer.

Agaricus blazei murill (ABM) mainly exerts its antitumor effect via modulation of the immune system. However, the immunomodulatory role of the ABM polysaccharide (ABMP) in mice with subcutaneously and intraperitoneally implanted MC38 tumor remains to be explored. This study aimed to define the progression effect of inhibiting tumor of ABMP in subcutaneous and intraperitoneal models and its effect on tumor microenvironment (TME) metabolism. In vitro experiments showed that ABMP could significantly promote the activity of CD8+ T immune cells in the co-culture system and promoted their colorectal cancer killing function (p < 0.05). In vivo animal exploration further showed that ABMP could inhibit the growth of intraperitoneal but not subcutaneous tumors. MCR-ALS analysis revealed a significant reduction in the signal of lipid-related spectral components in the TME of peritoneal tumors after ABMP intervention. In addition, preventive intervention with ABMP increased ω-3 polyunsaturated fatty acids content in intraperitoneal TME, revealing that ABMP shifted the metabolic landscape of the TME to promote T cell function and achieved immune regulation. These results suggest that the inhibitory effect of ABMP on colon cancer may be tumor stage-dependent, and that remodeling of fatty acid composition may be an important determinant of its action at any given stage.