cAMP and Pyk2 interact to regulate prostate cell proliferation and function

In cultured prostate cancer cells cAMP blocks proliferation and induces neuroendocrine differentiation. Pyk2 expression inversely correlates with malignancy of prostate cancer. The aim of this study was to investigate the interaction between cAMP and Pyk2 in the prostate. EPN cells, a line derived from human normal prostate expressing Pyk2, and EPN-PKM3 cells, an EPN clone bearing a Pyk2 kinase-negative mutant, were adopted as model system. cAMP inhibited cell growth in both prostate cell lines, and activated Pyk2, but not ERK1/2, in EPN cells. cAMP treatment, abolished the activation of AKT1, an important component of the pro-survival pathway, in the EPN cells but not in EPN-PKM3 cells. Finally, upon cAMP treatment, EPN and EPN-PKM3 cells exhibited different expression patterns of HOX genes, an important network controlling cell identity. These data demonstrated for the first time that Pyk2 and cAMP interact in regulating prostate cell functions and in "keeping" prostate identity.