Figure 5.

Drp1 depletion inhibits GBP2 mediated cell invasion and mitochondrial fission. Knockdown of endogenous Drp1 inhibits invasion abilities of breast cancer MDA-MB-231 and MDA-MB-436 cells with (a) IFN-γ treatment or (b) transfected with GFP-GBP2 or GFP as control. The histogram shows cell invasion. Data shown are mean±S.E.M. (n=4), *P<0.05. (c and d) Representative confocal images of MDA-MB-231 cells (upper) and MDA-MB-436 cells (lower) with IFN-γ treatment or GFP-GBP2 expression, transfected with scramble or Drp1 shRNA and stained with MitoTracker Red, show endogenous expression of Drp1 and mitochondrial morphology; green shows exogenous GBP2 expression. Scale bar, 10 mm. (e and f) A GFP-tagged Drp1 mutant, insensitive to Drp1 shRNA, was expressed in Drp1-silenced breast cancer cells with IFN-γ treatment or Flag-GBP2 expression for 48 h, and cells were then collected for western blotting analysis of Drp1 expression. (g and h) As described in panels (e and f), cells were collected for transwell invasion assays. n=4, mean±S.E.M. *P<0.05