Ginsenoside Rg3 targets Glut1 acetylation to restrain immunosuppressive TAM polarization and potentiate anti-PD-1 therapy in colorectal cancer

Tumor-associated macrophages (TAMs) are the most abundant infiltrating immune cells in tumors and contribute to the formation of an immunosuppressive niche. Ginsenoside Rg3, a triterpenoid glycoside derived from Panax ginseng, has been extensively documented to exert anti-tumor activities. However, whether the therapeutic efficacy of Rg3 against colorectal cancer (CRC) is closely associated with TAM-mediated immune suppression remains largely elusive. We investigated the immunomodulatory effects of Rg3 on TAM-mediated functions using murine CRC and human 3D organoid models. MS-DARTS technology was employed to identify the potential molecular targets of Rg3, which were further validated through CETSA, SPR, and molecular dynamics simulations. Metabolomic, proteomic, and transcriptomic analyses were performed to explore the metabolic and molecular mechanisms underlying Rg3-mediated tumor microenvironment (TME) remodeling. A macrophage-specific Glut1 knockout mouse model was established to assess the effects of Glut1 deficiency on TAM polarization and the therapeutic efficacy of Rg3. The treatment of Rg3 plus anti-PD-1 was evaluated to determine whether Rg3 enhances the anti-CRC effect of anti-PD-1. Rg3 inhibited CRC progression by modulating the immunosuppressive polarization of TAMs in a host immune-dependent manner. Rg3 directly binds to Glut1 on macrophages, thereby inhibiting p300/CBP-mediated acetylation and triggering metabolic reprogramming. This cascade reduces itaconate levels, leading to enhanced phosphorylation of JAK1 and subsequent activation of the STAT1 signaling pathway. By promoting STAT1 nuclear translocation, Rg3 increases the secretion of CXCL10/11, thereby facilitating the infiltration of CD8 + T cells into tumors. Rg3 enhances the therapeutic effect of anti-PD-1 against CRC progression, showing efficacy even in microsatellite stable CRC models. Rg3 is a promising candidate for targeting TAM metabolism to reshape the immunosuppressive TME and combat CRC development.