10.6084/m9.figshare.1568477.v2 Valentina Grossi Valentina Grossi Giuseppe Lucarelli Giuseppe Lucarelli Giovanna Forte Giovanna Forte Alessia Peserico Alessia Peserico Antonio Matrone Antonio Matrone Aldo Germani Aldo Germani Monica Rutigliano Monica Rutigliano Alessandro Stella Alessandro Stella Rosanna Bagnulo Rosanna Bagnulo Daria Loconte Daria Loconte Vanessa Galleggiante Vanessa Galleggiante Francesca Sanguedolce Francesca Sanguedolce Simona Cagiano Simona Cagiano Pantaleo Bufo Pantaleo Bufo Senia Trabucco Senia Trabucco Eugenio Maiorano Eugenio Maiorano Pasquale Ditonno Pasquale Ditonno Michele Battaglia Michele Battaglia Nicoletta Resta Nicoletta Resta Cristiano Simone Cristiano Simone Loss of STK11 expression is an early event in prostate carcinogenesis and predicts therapeutic response to targeted therapy against MAPK/p38 Taylor & Francis Group 2018 apoptosis autophagy AMPK drug resistance MAPK/p38 prostate cancer STK11 2018-08-31 21:21:36 Dataset https://tandf.figshare.com/articles/dataset/Loss_of_STK11_expression_is_an_early_event_in_prostate_carcinogenesis_and_predicts_therapeutic_response_to_targeted_therapy_against_MAPK_p38/1568477 <p>Prostate cancer (PCa) is the second leading cause of cancer-related death in men; however, the molecular mechanisms leading to its development and progression are not yet fully elucidated. Of note, it has been recently shown that conditional <i>stk11</i> knockout mice develop atypical hyperplasia and prostate intraepithelial neoplasia (PIN). We recently reported an inverse correlation between the activity of the STK11/AMPK pathway and the MAPK/p38 cascade in HIF1A-dependent malignancies. Furthermore, MAPK/p38 overactivation was detected in benign prostate hyperplasia, PIN and PCa in mice and humans. Here we report that STK11 expression is significantly decreased in PCa compared to normal tissues. Moreover, STK11 protein levels decreased throughout prostate carcinogenesis. To gain insight into the role of STK11-MAPK/p38 activity balance in PCa, we treated PCa cell lines and primary biopsies with a well-established MAPK14-MAPK11 inhibitor (SB202190), which has been extensively used in vitro and in vivo. Our results indicate that inhibition of MAPK/p38 significantly affects PCa cell survival in an STK11-dependent manner. Indeed, we found that pharmacologic inactivation of MAPK/p38 does not affect viability of <i>STK11</i>-proficient PCa cells due to the triggering of the AMPK-dependent autophagic pathway, while it induces apoptosis in <i>STK11</i>-deficient cells irrespective of androgen receptor (AR) status. Of note, AMPK inactivation or autophagy inhibition in <i>STK11</i>-proficient cells sensitize SB202190-treated PCa cells to apoptosis. On the other end, reconstitution of functional <i>STK11</i> in <i>STK11</i>-deficient PCa cells abrogates apoptosis. Collectively, our data show that STK11 is a key factor involved in the early phases of prostate carcinogenesis, and suggest that it might be used as a predictive marker of therapeutic response to MAPK/p38 inhibitors in PCa patients.</p>