Colon cancer is one of the leading causes of cancer-related mortality worldwide. Current treatments, including surgery, chemotherapy, and radiation therapy, often have limited efficacy due to tumor heterogeneity and resistance mechanisms. Therefore, there is a critical need for novel therapeutic strategies that can enhance the immune response against colon cancer cells while promoting their efficient clearance. In this study, we investigated the anti-tumor effects of Ro 90-7501, a specific small molecule, in colon cancer cell lines (HCT8 and SW480) and in vivo models. MTS, EdU, Scratch Wound and Transwell assays were performed to detect the cell proliferation and metastasis. Additionally, flow cytometry and immunofluorescence staining were used to analyze changes in apoptosis and necrosis. Furthermore, we examined its ability to induce immunogenic cell death (ICD) and promote retinoic acid-inducible gene I (RIG-I)-mediated autophagy. The expression levels of key molecules involved in ICD and autophagy were assessed using Western blot analysis, immunofluorescence staining, and enzyme-linked immunosorbent assay (ELISA). Our findings demonstrated that Ro 90-7501 significantly suppressed colon cancer cell proliferation and metastasis, inducing apoptosis and necrosis. Mechanistically, Ro 90-7501 triggered ICD by upregulating the exposure of calreticulin (CRT) on the cell surface and increasing the release of high mobility group box 1 (HMGB1) and extracellular ATP levels. Concurrently, it promoted RIG-I-mediated autophagy via the MAVS-TRAF6 signaling axis, evidenced by increased expression of autophagy-related genes, such as microtubule-associated protein 1 light chain 3 (LC3) and Beclin 1 proteins, coupled with a reduction in P62 protein. Additionally, Ro 90-7501 treatment activated the RIG-I-MAVS-TRAF6 signaling axis in colon cancer cells. Furthermore, Ro 90-7501 enhanced the secretion of pro-inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNFα), thereby activating the immune response. In conclusion, Ro 90-7501 exhibits potent anti-tumor activity against colon cancer by inducing ICD and promoting RIG-I-mediated autophagy. These results suggest that Ro 90-7501 may serve as a promising therapeutic candidate for colon cancer treatment by enhancing both intrinsic cellular processes and adaptive immune responses. Further studies are warranted to elucidate the detailed mechanisms underlying these effects and to evaluate its therapeutic potential in clinical settings.
Keywords: Autophagy; Colon cancer; Immunogenic cell death; RIG-I; Ro 90-7501.
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