Requirements IDH2 regulation of tumor cell motility. A) PC3 cells transfected with siCtrl or siIDH2 were analyzed for cell migration (top) or invasion across Matrigel-coated Transwell inserts (bottom). Representative images of DAPI-stained nuclei of migrated or invaded cells are shown. B) PC3 (top, n = 21–25) or DU145 (bottom, n = 22–24) cells were transfected with siCtrl, 3 independent IDH2-directed siRNAs (#1, #2, #3), or IDH2-directed pooled siRNA (P) and analyzed for Matrigel invasion. Means ± sd. *P = 0.02, ***P < 0.0001. C) PC3 cells transfected as in A were reconstituted with IDH2 cDNA and analyzed for cell migration (top, n = 21–22) or Matrigel invasion (bottom, n = 21–22). Means ± sd. ***P < 0.0001. D, E) PC3 cells transfected with siCtrl or siIDH2 were further transfected with Drp1-directed siRNA (siDrp1) and analyzed by Western blotting (D) or Matrigel invasion [n = 37–45 (E)]. Means ± sd. ***P < 0.0001. F, G) PC3 cells transfected with siCtrl or siIDH2 were incubated with small molecule Akt inhibitor, MK2206, and analyzed by Western blotting (F) or Matrigel invasion (G). siCtrl, control nontargeting siRNA; ns, not significant; p, phosphorylated. Means ± sd (n = 22–24). ***P < 0.0001.