Enhancing therapeutic efficacy in triple-negative breast cancer and melanoma: synergistic effects of modulated electro-hyperthermia (mEHT) with NSAIDs especially COX-2 inhibition in in vivo models.

Triple-negative breast cancer (TNBC) is a leading cause of cancer mortality and lacks modern therapy options. Modulated electro-hyperthermia (mEHT) is an adjuvant therapy with demonstrated clinical efficacy for the treatment of various cancer types. In this study, we report that mEHT monotherapy stimulated interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) expression, and consequently cyclooxygenase 2 (COX-2), which may favor a cancer-promoting tumor microenvironment. Thus, we combined mEHT with nonsteroid anti-inflammatory drugs (NSAIDs): a nonselective aspirin, or the selective COX-2 inhibitor SC236, in vivo. We demonstrate that NSAIDs synergistically increased the effect of mEHT in the 4T1 TNBC model. Moreover, the strongest tumor destruction ratio was observed in the combination SC236 + mEHT groups. Tumor damage was accompanied by a significant increase in cleaved caspase-3, suggesting that apoptosis played an important role. IL-1β and COX-2 expression were significantly reduced by the combination therapies. In addition, a custom-made nanostring panel demonstrated significant upregulation of genes participating in the formation of the extracellular matrix. Similarly, in the B16F10 melanoma model, mEHT and aspirin synergistically reduced the number of melanoma nodules in the lungs. In conclusion, mEHT combined with a selective COX-2 inhibitor may offer a new therapeutic option in TNBC.