Etoposide

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.

To detect the effect of apoptotic-inducing factors on the activities of IGF2 axis, 0.5–1.5 × 10⁶ cells were seeded into 6-well dishes, or 1–2 × 10⁶ cells were seeded into 60 mm dishes. After attachment overnight, dishes were washed twice by PBS. For starvation treatment assay, the medium was changed with serum-free α/Ham medium containing 10 μg/ml transferrin or α/Ham medium supplemented with 10% FBS, then cells were harvested 1–4 days later. For chemotherapy drugs treatment assay, the medium was changed with McCoy's 5A for G401 or RPMI-1640 for BT16 medium supplemented with 10% FBS, in addition of DMSO (SIGMA), 0.5 μM Epirubicin HCl (Dalian Meilun Biological Technology), or 5 μM Etoposide (Dalian Meilun Biological Technology), then cells were harvested 3 days later.