3-MA inhibited autophagy and enhanced apoptosis induced by paclitaxel treatment in FLCN-deficient cells. A. Cells were pretreated with 5 mM 3-MA for 3 hours and subsequently treated with 100 nM paclitaxel or a control vehicle for 24 hours with or without bafilomycin A1 treatment. LC3 proteins were dramatically decreased after autophagy inhibitor 3-MA. B. Cells were treated with 3-MA and different concentrations of paclitaxel, MTT assay showed that cell viability was more significantly reduced in FLCN-deficient cells compared to 3-MA untreated cells (*: p < 0.05. UOK257 + Paclitaxel vs UOK257 + Paclitaxel + 3-MA; ACHN 5968 + Paclitaxel vs ACHN 5968 + Paclitaxel + 3-MA; n = 15). C. TUNEL assay showed that more apoptotic cells were detected among FLCN-deficient cells treated with 3-MA and paclitaxel (*: p < 0.05. UOK257: Paclitaxel vs UOK257+ 3-MA; ACHN 5968: Paclitaxel vs Paclitaxel + 3-MA; n = 15).