LIMK2-mediated phosphorylation of PTEN contributes to aggressive oncogenic phenotypes in 22Rv1 cells. (A) Expression of WT and 5A-PTEN impaired cell proliferation in 22Rv1 cells. 22Rv1, LIMK2–22Rv1, PTEN-22Rv1 and 5A-PTEN-22Rv1 cells were cultured in 96-well plates for 24, 48, and 72h and subjected to MTT assay. (B) Data showing increased cell proliferation in 22Rv1, PTEN-22Rv1 and 5A-PTEN-22Rv1 cells upon LIMK2 overexpression. (C) LIMK2 depletion substantially reduced cell growth in 22Rv1, PTEN-22Rv1 and 5A-PTEN-22Rv1 cells. (D) 5A-PTEN shows maximal inhibition of colony formation in a soft agar assay in 22Rv1 cells. *P < 0.05 compared to vector-expressing control analyzed by one-way ANOVA. (E) PTEN and 5A-PTEN inhibit cell migration in 22Rv1 cells. Chemotaxis assay was performed in 22Rv1, PTEN-22Rv1 and 5A-PTEN-22Rv1 cells using Boyden chambers. Histogram shows mean ± SEM of three independent experiments. *P < 0.05 compared to vector control. (F) Representative images of chemotaxis assay. Magnification, 200×. (G and H) LIMK2 overexpression increases cell motility in both PTEN-22Rv1 and 5A-PTEN-22Rv1 cells. (I and J) LIMK2 depletion inhibits cell motility in both PTEN-22Rv1 and phospho-resistant 5A-PTEN-22Rv1 cells. (K) Variation in AR levels in response to PTEN as assayed using ectopic expression of WT and 5A PTEN. *P < 0.05, **P < 0.005. (L) Quantification of data shows significant decrease in AR levels in both WT and 5A-mutant expressing cells. (M) LIMK2-mediated phosphorylation of PTEN increases enzalutamide-sensitivity. 22Rv1, PTEN-22Rv1 and 5APTEN-22Rv1 cells were plated overnight, enzalutamide (1 μM) was added and cells were grown for additional 24, 48 or 72h, followed by MTT assay. (N) PTEN overexpression increases LIMK2 inhibitor sensitivity in 22Rv1 cells. 22Rv1, PTEN-22Rv1 and 5A-PTEN-22Rv1cells were plated overnight, followed by LIMK2 inhibitor (10 μM) treatment. The cells were grown for additional 24, 48 or 72h, followed by MTT assay. (O) 5A-PTEN overexpression sensitizes 22Rv1 cells to LIMK2 inhibitor and enzalutamide, 22Rv1, PTEN-22Rv1 and 5A-PTEN-22Rv1cells were plated overnight, followed by enzalutamide (1 μM) or LIMK2 inhibitor (10 μM) treatments either independently or in combination. The cells were grown for additional 72h, followed by MTT assay.