Metformin boosts doxorubicin efficacy and increases CD8 + T cell frequency in mouse breast cancer

Breast cancer is a leading cause of cancer-related deaths among women worldwide. The presence and function of CD8 + T cells in the tumor microenvironment have been associated with better patient outcomes. Drug toxicity has posed a significant challenge to the clinical implementation of chemotherapy-based strategies in cancer treatment. In this study, we employed flow cytometry to investigate the potential synergistic immunomodulatory effects on CD8 + T cells in a mouse model of breast cancer by combining metformin, an anti-diabetic medication, with doxorubicin. Through flow cytometry analysis, we observed that the combination of the two drugs led to an increased percentage of CD8 + T cells compared to either drug alone. The modulation of HIF-1α and STAT3 gene expression in the combination group further confirmed the efficacy of this approach. Our findings suggest that combining metformin with doxorubicin can enhance the anticancer activity of doxorubicin and decrease its cytotoxicity in a 4T1 breast cancer mouse model.