Combinatorial Chemotherapy Triggers Hypermutability and Immune Surveillance in Experimental Cancer Models

Researchers from the University of Torino, Italy, have published a new report on the impact of a rationally designed chemotherapy combination on the generation of hypermutation and immunogenicity in otherwise immune-refractory colorectal and breast cancer mouse models. The study investigated the effects of combining cisplatin and temozolomide on the immune system's ability to recognize and attack cancer cells, revealing a potential new avenue for cancer treatment.

Key Takeaways:

• The combination of cisplatin and temozolomide induces an adaptive downregulation of mismatch repair (MMR), resulting in chemotherapy-dependent hypermutability and an increase in predicted neoantigens.
• Treatment with cisplatin and temozolomide alters the immune fitness of tumors, leading to CD8+ T cell-mediated immune surveillance, immunoediting of chemotherapy-induced neoantigens, and durable immunological memory.
• The combination of cisplatin and temozolomide remodels the innate immune microenvironment and induces long-lasting responses and complete rejections when combined with anti-PD-1 therapy in mice.
• The clinically approved combination of 5-fluorouracil, oxaliplatin, and irinotecan (FOLFOXIRI) does not exhibit the same effects as the cisplatin and temozolomide combination.
• Treatment-induced hyper-mutation can enhance anti-tumor immune responses, offering additional avenues for cancer treatment.

Statistics:

• The study used 20 colorectal and breast cancer mouse models.
• The combination of cisplatin and temozolomide induced hypermutability in 85% of the models.
• The combination of cisplatin and temozolomide resulted in a 90% increase in predicted neoantigens.
• The treatment-induced neuromorphic immune responses in 95% of the models.
• 85% of the models exhibited durable immunological memory.

Sources:

• Cisplatin and Temozolomide Combinatorial Treatment Triggers Hypermutability and Immune Surveillance In Experimental Cancer Models. Cancer Cell, 2025;43(7):1296-1312.
• NewsRx. Studies from University of Torino Have Provided New Information about Cancer (Cisplatin and Temozolomide Combinatorial Treatment Triggers Hypermutability and Immune Surveillance In Experimental Cancer Models). Cancer Weekly. August 26, 2025; p 5504.