Reprogramming Tumor-Associated Macrophages To Reverse EGFR^T790M Resistance by Dual-Targeting Codelivery of Gefitinib/Vorinostat

Gefitinib is a first-line therapy in the EGFR-mutated nonsmall cell lung cancer (NSCLC). However, the development of drug resistance is almost unavoidable, thus leading to an unsustainable regimen. EGFR^T790M mutation is the major cause responsible for the molecular-targeting therapy failure in NSCLC. Although the recently approved osimertinib is effective for the EGFR^T790M-positive NSCLC, the osimertinib-resistant EGFR mutation is rapidly developed, too. In this study, we proposed a tumor-associated macrophage (TAM) reprogramming strategy for overcoming the EGFR^T790M-associated drug resistance via a dual-targeting codelivery system of gefitinib/vorinostat that acted on both TAM with overexpression of mannose receptors and the HER-2 positive NSCLC cells. The trastuzumab-modified, mannosylated liposomal system was able to repolarize the protumor M2 phenotype to the antitumor M1 and cause the elevating ROS in the cancer cells, consequently modulating the intracellular redox balance via ROS/NOX3/MsrA axis. The suppressed MsrA facilitated the EGFR^T790M degradation through 790M oxidation by ROS, thus resensitizing the EGFR^T790M-positive cells to gefitinib. The dual-targeting codelivery and TAM-reprogramming strategies provided a potential method for rescuing the EGFR^T790M-caused resistance to tyrosine kinase inhibitor treatment