Cucurbitane Triterpenoid from Momordica charantia Induces Apoptosis and Autophagy in Breast Cancer Cells, in Part, through Peroxisome Proliferator-Activated Receptor γ Activation
Figure 4
Induction of autophagy in MCF-7 cells by DMC. (a) Electron microscopic analysis of autophagosome formation in vehicle- or drug-treated MCF-7 cells as described in Section 2. Arrow: autophagosomes. (b) Fluorescent confocal microscopic analysis of drug-induced autophagosome formation in MCF-7 cells ectopically expressing GFP-LC3. The arrow indicates LC3-positive puncta in DMC-treated cells. MCF-7 cells transiently transfected with GFP-LC3 plasmids were treated with DMSO, 15 μM DMC, or 100 nM rapamycin for 24 h and then fixed by 3.7% paraldehyde and examined by confocal microscopy. (c) Dose- and (d) time-dependent effects of DMC on the conversion of LC3-I to LC3-II and/or the expression of Atg7 and Beclin 1. MCF-7 cells were treated with DMC at indicated concentrations or DMSO for 72 h.
