Figure 5

Aberrant nuclear localization of PTEN E307K mutant. (A) Total cell lysate (Lys) from MDA-MB-453 was fractionated into cytosolic (Cyt) and nuclear (Nuc) fractions with the NE-PER kit (Pierce, IL). Tubulin and Sp1 were used as cytosolic and nuclear markers, respectively. Similar results were obtained from two independent experiments. (B) MCF7 cells were transfected by lipofection with the indicated expression plasmids and cell lysates were fractionated after 24 h. Purity of the cytosolic and nuclear fractions was confirmed with p38 and Sp1, respectively. Results represent data from two experiments performed in duplicates. Bars, SE. *, p < 0.05, one-tailed t-test (right panel). (C) Pten ^-/- MEFs expressing WT and E307K were treated with PBS (upper panels) or 5 μM cisplatinum (+CP)(Sicor Inc., CA) for 48 hours. Cells were stained with PI. Note the reduction in the % of sub-G1 cells in E307K+CP. (D) Western blotting analysis of PTEN expression. Anti-PTEN polyclonal antibody (#9552) was used in all panels. Abbreviations: C, control. *, background signals.