Pepstain a

BA (Meilunbio, Dalian, China; MB5971), Chloroquine (Sigma, St. Louis, MO, USA; C6628), E-64d (Sigma, E8640) and Pepstain A (Sigma, P4265) were dissolved in DMSO (Sigma, D2650). Acridine orange (Sigma, A6014) and 3-MA (Meilunbio, MB5063) were dissolved in PBS. MG132 (Meilunbio, MB5137), Etoposide (Meilunbio, MB1102-S) and CHX (Meilunbio, MB2208) were dissolved in DMSO. LC3 (MBL, Beijing, China; PM036) was bought for immunoblot or immunofluorescence analysis. Antibodies including AKT, phosphorylation of AKT (Ser473; 4060), MTOR, phosphorylation of MTOR (Ser2443; 5535), PARP (116 and 89 kd; 9542S), BAX (5023), phosphorylation of p53 (Ser15; 9286) and GAPDH (Santa Cruz Biotechnology(CA, USA) 5174) were purchased from CST (Beverly, MA, USA). Cleaved-PARP antibody was purchased from Sigma (SAB4500487). p53 (SC-126) and LAMP1 (SC-5570) were purchased from Santa Cruz Biotechnology (CA, USA) for immunoblot or immunofluorescence analyses.

Cells at desired concentrations were seeded into wells of a plastic plate, Petri dishes or culture flasks and taxanes were applied after a 24-h preincubation. After the incubation period, cells were harvested by low-speed centrifugation (2000 rpm, 9 min, 4°C), washed in PBS and centrifuged. Cell pellets were stored at -80°C. Frozen pellets were resuspended in RIPA buffer (Sigma Aldrich) containing a 1% mixture of protease inhibitors P8340 (AEBSF 104 mM, Aprotinin 80 μM, Bestatin 4 mM, E-64 1.4 mM, Leupeptin 2 mM, Pepstain A 1.5 mM, Sigma Aldrich). Protein lysates were centrifuged (14,000 rpm, 20 min, 4°C) and the supernatants containing proteins were stored at -80°C. Protein lysates were than analyzed using western blot.