Loss of PTEN leads to hyperactivation of AKT in the nucleus of breast and thyroid cancer cells. A, Left, Whole-cell lysates (WCL) were collected from MCF-7 cells stably expressing PTEN-shRNA or shRNA vector control. Western blots showed that PTEN-shRNA knocked down PTEN expression accompanied by increased P-AKT. Right, Cytoplasmic (Cyt) and nuclear (Nuc) fractions of MCF-7 cells stably expressing PTEN-shRNA or shRNA vector control were isolated and immunoblotted for P-AKT. B, Left, Whole cell lysates (WCL) were collected from BCPAP cells transfected with PTEN-shRNA or shRNA vector control. Western blots showed that PTEN-shRNA knocked down PTEN expression accompanied by increased P-AKT. Right, Cytoplasmic (Cyt) and nuclear (Nuc) fractions of BCPAP cells expressing PTEN-shRNA or shRNA vector control were isolated and immunoblotted for P-AKT. C and D, Charts show quantification of Western blot densitometry in A and B, separately (n = 2 experiments for each cell line).