Gefitinib Triggers PC-9Lung Adenocarcinoma Cells Apoptosis Through Induction Of Autophagy

Autophagy is a highly conserved metabolic process in eukaryote. It plays critical rolesin cell renewal, tissue and organ development and differentiation. Mounting evidencesuggest that cancer cells undergo autophagy during hypoxia, nutrition deprivation and cellorganelles damage. Autophagy sometimes enables cancer cell metabolism and energysupply, therefore maintains cancer cells survival in unfavorable condition. However,exceeding autophagy might lead to severe cell damage and death. Given theseconsideration, autophagy is a double-side sword. Manipulating autophagy might be apromising candidate in individualized cancer therapy. The present study aims toinvestigate effects of Gefitinib on EGFR mutated PC-9lung cancer cells autophagy and itscrosstalks with apoptosis.Section1: By employing MTT assay, the IC50of Gefitinib in PC-9cells was calculated.PC-9cells apoptosis was measured by Annexin V-FITC/PI flow cytometry.Section2: By using morphological and molecular approaches, we explored effects ofGefitinib on PC-9cells autophagy. Acridine orange staining revealed large amounts ofacidic vesicular organelles upon Gefitinib treatment. Laser confocal microscopy alsoindicated GFP-LC3puncta formation after Gefitinib treatment. Autophagosomes wereobserved by the transmission electron microscope. We also detected expressions of LC3autophagy markers expressions, and the results suggested Gefitinib prompted LC3Iâ†'LC3 II transformation.Section3: We focused on Gefitinib-induced PC-9cells autophagy function in thissection. PC-9cells were treated with Gefitinib and autophagy inducer Rapamycin, flowcytometry demonstrated increased cell apoptosis in the combined treatment group.Western blot analysis showed p-mTOR and p-Akt were further inhibited. On the contrary,the autophagy inhibitor3-methyladenin (3-MA) abrogated apoptsis triggered by Gefitinib.Furthermore,3-MA antagonized Gefitinib on p-mTOR and p-Akt inhibition. Collectively,these results highlighted Gefitinib-induced autophagy is a proapoptotic event. Inhibition ofautophagy might attenuate Gefitinib efficiency.