Cytoplasmic p44 promotes and nuclear p44 inhibits proliferation of prostate epithelial cells.

<p>(A) Nuclear p44 enhanced expression of prostate-secreted proteins. A, Quantitative RT-PCR analysis of expression of prostate-secreted proteins. Total RNAs were isolated from LT^ts-ECs cultured at 33°C or 37°C for 6 days, and amounts of specific RNAs were measured by RT-PCR. Relative expression indicates specific AR expression in LTA^ts-ECs cultured at 37°C divided by amounts of the same RNA in LTA^ts-ECs cultured at 33°C. (B) Cytoplasmic p44 fully restored the growth inhibition of prostate epithelial cells induced by the non-permissive temperature. Growth curves of LTA^ts-ECs infected with control lentivirus (Og2) or lentivirus expressing p44, NES-p44, or NLS-p44 and grown at 33°C or 37°C. One-way ANOVA analysis: F = 196.5, p = <0.0001, R square = 0.9861. The p value of unpaired Student’s t-Test of data between 37°C-Og2 and 33°C-NESp44, 33°C-NESp44, 37°C-NESp44, 33°C-NLSp44, or 37°C-NLSp44 is <0.0001, <0.0001, 0.0053, 0.0017, or 0.0038. (C) Nuclear p44 inhibited proliferation of prostate epithelial cells. LTA^ts-ECs infected with control lentivirus (Og2) or lentivirus expressing p44, NES-p44, or NLS-p44 were allowed to grow in the presence of BrdU and immunostained with an anti-BrdU antibody (shown blown).