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bioRxiv · 10.1101/2025.09.27.679002

Macrophage-derived WNT regulates tumor immune microenvironment to reduce colitis-associated colon cancer

Abstract

Prolonged colonic inflammation and ulcerative colitis lead to colon cancer. The rapid growth and treatment-resistant nature of these tumors are primarily influenced by an immunosuppressive tumor microenvironment, which is led by tumor-associated macrophages (TAMs). However, factors influencing or regulating the immunosuppressive nature of TAMs have not been sufficiently studied. In this manuscript, we use a mouse model of colitis-associated colorectal cancer (CRC) to demonstrate that WNT expression in TAMs regulates their immunosuppressive function by inhibiting Glycogen synthase kinase-3 beta (GSK-3{beta}) within the macrophages, possibly through an autofeedback loop. GSK3{beta} is a positive regulator of PD-1 and PDL1 expression in macrophages and promotes an immunosuppressive microenvironment. Therefore, GSK-3{beta} inhibition alters the immunosuppressive nature of the immune microenvironment and effectively controls tumor growth. In Csf1r-iCre; Porcnfl/fl mice, the absence of macrophage-derived WNT promotes tumor growth in the model of colitis-associated colon cancer. Absence of macrophage-derived WNT stabilizes GSK-3{beta} in macrophages and promotes an immunosuppressive tumor microenvironment. We also show that pharmacological inhibition of GSK-3{beta} in a macrophage-specific manner, achieved by systemic delivery of a lipo-GSK3{beta} inhibitor, effectively inhibits tumor growth. Therefore, this manuscript demonstrates for the first time that the macrophage-specific modulation of GSK3{beta} can be a potential target to treat colitis-associated colon cancer.

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BibTeXRIS

Bhanja, P., Chugh, R. M., Rehman, S., Krepel, S., Mitra, A., Gupta-Saraf, P., Diaz-Olea, X., Pathak, H., Kasi, A., Saha, S.. 2025-09-29. Macrophage-derived WNT regulates tumor immune microenvironment to reduce colitis-associated colon cancer. https://doi.org/10.1101/2025.09.27.679002

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