Figure 1. PTEN regulates expression of secreted factors at the translational and transcriptional levels.

(A) Western Blot analysis demonstrating the effect of functional Phosphatase and Tensin homolog (PTEN) expression on phosphorylated Akt (p-Akt) levels following infection with wild-type PTEN Adenovirus (Ad-PTEN-WT), the catalytically inactive PTEN mutant (Ad-PTEN-CS), and LacZ (Ad-LacZ) control in whole cell extracts (WCE) of LNCaP and PC3 cells. Total Akt was used as a control for p-Akt levels and Actin was used as a loading control (Left Panel). Secretion of soluble Prorenin Receptor (sPRR), Spondin 2 (SPON2) and Cystatin C (CST3) was assessed by western blotting in the conditioned media (CM) of the same cells following infection with the adenoviruses indicated. Ponceau staining was used as the loading control (Right Panel) (n = 3). (B) qRT-PCR analysis demonstrating mean fold change in the mRNA expression of Prostate Specific Antigen (PSA) (^* P = 0.014), Inulin-like growth factor binding protein 2 (IGFBP-2), Prorenin Receptor (PRR), SPON2 (^** P = 0.006), and CST3 in Ad-PTEN-WT-infected LNCaP cells normalized to Ad-LacZ controls (n = 4). (C) Polysome profiles of PSA, IGFBP-2, and PRR in Ad-LacZ and Ad-PTEN-WT-infected LNCaP cells. The levels of transcripts in each fraction were quantified by qRT-PCR. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as a control. Data are presented as the mean ± SEM. Statistical tests conducted using Student’s t test.