Apatinib reverses paclitaxel-resistant lung cancer cells (A549) through blocking the function of ABCB1 transporter

Background/Aim: Multidrug resistance (MDR) is often associated with overexpression of P-glycoprotein (ABCB1) in cancer cells. Apatinib is a novel Vascular endothelial growth factor receptor-TKI (VEGFR-TKI) which inhibits the function of ABCB1 in certain cancers. This study aimed to investigate the effect of apatinib on the reversal of paclitaxel (PTX) resistance in A549 lung cancer cells (A549/PTX) and related mechanisms. Materials and Methods: A549/PTX cells were treated with apatinib alone, PTX alone, or PTX and apatinib. Cell viability was measured by the CCK8 assay. Apoptosis rate, cell-cycle arrest, Rhodamine efflux and reactive oxygen species (ROS) generation were determined by flow cytometry. The intracellular paclitaxel concentration was measured by ultra performance liquid chromatography (UPLC). Protein levels were analyzed by western blotting. Results: A549/PTX cells had significant resistance to PTX and higher expression of ABCB1 compared to A549 cells. Apatinib increased the cytotoxicity of PTX, enhanced PTX-induced apoptosis and cycle arrest, and triggered intracellular ROS generation in A549/PTX cells. In addition, apatinib treatment increased the concentration of intracellular PTX in A549/PTX cells. Apatinib-PTX combination inhibited AKT and ERK pathways. Conclusion: Apatinib reverses the drug resistance to PTX in A549 PTX-resistant cells through inhibiting the function of ABCB1 and resumes anti-cancer effects.