Thermal cycling hyperthermia sensitizes non-small cell lung cancer A549 cells to EGFR-tyrosine kinase inhibitor Erlotinib

Molecular targeted therapy has emerged as a mainstream treatment for non-small cell lung cancer (NSCLC), the most common lung cancer, which has been the leading cause of cancer death in both genders. Erlotinib (Erl), a targeted therapy inhibiting epidermal growth factor receptor (EGFR) pathways, has been proved to have noticeable response rate for NSCLC cells. However, limited efficacy arises due to intrinsic and acquired resistance among most NSCLC patients. Therefore, sensitizers are required to potentiate the efficacy of Erl in NSCLC treatment. The study proposed a novel thermal therapy, thermal cycling hyperthermia (TC-HT), as a supplement to amplify the effects of Erl. We found that TC-HT remarkably reduced the half-maximal inhibitory concentration (IC50) of Erl to as little as 0.5 M and demonstrated that TC-HT could sensitize A549 NSCLC cells to Erl via the downstream of EGFR signaling cascades. Furthermore, combination treatment induced G2/M cell cycle arrest, and inhibition of cell proliferation and migration. Besides, via raising the high temperature of TC-HT slightly, TC-HT treatment alone can produce excellent antineoplastic effect without hurting the normal cells. The method is expected to be applicable to other combination therapies and may be a starter for more sophisticated, side-effect-free anticancer treatments.