Figure 2
Metformin induces mitochondrial swelling in cancer cells in vitro and in vivo. (A) Electron microscopy (EM) of LNCaP (PCa) and A549 (lung cancer) cells treated with 1 and 5 mM metformin for 24 h. The graphs represent the mean of the relative mitochondrial area. An example of swollen mitochondria with modifications of the IMM is noted with an arrow. The inset shows a magnified view of a representative mitochondrion. (B) Electron microscopy images of representative mitochondria from tumor xenografts, and quantification of the relative mitochondrial area in the corresponding tumors. The error bars represent the standard error of the mean (sem). (C) Electron microscopy images of LNCaP cells treated with metformin and 40 µM 2-ABP or 10 µM KB-R7943 for 24 h. Quantification of the mitochondrial area is reported in the graph (left panel). For each condition, 60 to 100 mitochondria from several cells were analyzed by EM. (D) Quantification of MCU mRNA in LNCaP cells treated with metformin for 24 h. The differences are significant with p < 0.05 (*) and p < 0.001 (***).
