The plant alkaloid voacamine induces apoptosis-independent autophagic cell death on both sensitive and multidrug resistant human osteosarcoma cells

Abbreviations: ATG, autophagy-related gene; AVOs, acidic vesicular organelles; BAF, bafilomycin A1; DAPI, 4', 6'-diamidine-2-phenylindole dihydrochloride; DOX, doxorubicin; FBS, fetal bovine serum; imps, intramembrane particles; LC3, microtubule-associated protein I (MAP1) light chain 3; MDC, monodansylcadaverine; MDR, multidrug resistance, PARP, poly (ADP-ribose) polymerase; PI, propidium iodide; PS, phosphatidylserine; SEM, scanning electron microscopy; TEM, transmission electron microscopy; VOA, voacamine; WM, worumannin; 3-MA, 3-methyladenine