Genetically distinct microenvironment determines cancer survival and response to therapy in mice

Genetic uniqueness of the tumor microenvironment significantly influences cancer growth, survival, and response to therapy, independent of the cancer cell’s intrinsic properties or the adaptive immune system. Using genetically distinct Rag1-/- mouse models, this study shows that different strains exhibit varied tumor growth kinetics and survival outcomes when xenografted with identical leukemic and solid tumor cell lines. This study further highlights the critical role of the myeloid immune compartment and shows that disrupting both lymphoid and myeloid systems alters cancer progression. These results also reveal that the tumor microenvironment can permanently alter cancer cell phenotypes and significantly affect chemotherapy efficacy, as seen with Cisplatin’s varying effects across strains. These findings underscore the importance of considering genetic background in preclinical cancer models, suggesting that reliance upon a single mouse strain may lead to incomplete conclusions about cancer biology and treatment efficacy.