FH535-mediated inhibition of Wnt/β-catenin suppresses CRC growth and invasion and alters MCP1 and MCP2 expression with potential immunological implications.

Background: The Wnt/β-catenin signaling pathway plays a key role in colorectal cancer (CRC) progression, but its broader biological effects, when blocked, remain poorly understood. In this study, we examined the direct antitumor effects and the impact on the tumor microenvironment of FH535, a small-molecule inhibitor of Wnt/β-catenin and PPARδ signaling, in human CRC cells. Methods: We treated HCT116 and HT29 colorectal cancer cell lines with different doses of FH535. We measured changes in cell viability, colony-forming ability, movement, invasion, cell death, and cell-cycle stages. We used Western blotting to check key proteins involved in Wnt/β-catenin signaling, cell-cycle control, DNA damage, and cell death. To make sure the effects were specific to the pathway, we also used siRNA to silence β-catenin. We then measured the levels of the chemokines MCP1 (CCL2) and MCP2 (CCL8) after both drug treatment and gene silencing. Results: FH535 treatment reduced cell viability and colony-forming ability as the dose increased. It also reduced the cells' ability to move and invade. These changes were accompanied by increased cell death, as evidenced by flow cytometry and caspase-3 cleavage. Levels of total and phosphorylated β-catenin, cyclin D, and survivin also went down. Both FH535 treatment and β-catenin silencing strongly reduced MCP1 and MCP2 levels. Conclusion: FH535 shows antitumor effects in colorectal cancer by blocking Wnt/β-catenin signaling. This results in reduced cell growth, decreased movement, and increased cell death. Lower levels of MCP1 and MCP2 suggest this pathway also affects immune responses. These results support targeting Wnt/β-catenin as a possible treatment for CRC.