BACKGROUND: Prostate cancer develops through malignant transformation of the prostate epithelium in a stepwise, mutation-driven process. Although activator protein-1 transcription factors such as JUN have been implicated as potential oncogenic drivers, the molecular programs contributing to prostate cancer progression are not fully understood. METHODS: We analyzed JUN expression in clinical prostate cancer samples across different stages and investigated its functional role in a Pten-deficient mouse model. We performed histopathological examinations, transcriptomic analyses and explored the senescence-associated secretory phenotype in the tumor microenvironment. RESULTS: Elevated JUN levels characterized early-stage prostate cancer and predicted improved survival in human and murine samples. Immune-phenotyping of Pten-deficient prostates revealed high accumulation of tumor-infiltrating leukocytes, particularly innate immune cells, neutrophils and macrophages as well as high levels of STAT3 activation and IL-1β production. Jun depletion in a Pten-deficient background prevented immune cell attraction which was accompanied by significant reduction of active STAT3 and IL-1β and accelerated prostate tumor growth. Comparative transcriptome profiling of prostate epithelial cells revealed a senescence-associated gene signature, upregulation of pro-inflammatory processes involved in immune cell attraction and of chemokines such as IL-1β, TNF-α, CCL3 and CCL8 in Pten-deficient prostates. Strikingly, JUN depletion reversed both the senescence-associated secretory phenotype and senescence-associated immune cell infiltration but had no impact on cell cycle arrest. As a result, JUN depletion in Pten-deficient prostates interfered with the senescence-associated immune clearance and accelerated tumor growth. CONCLUSIONS: Our results suggest that JUN acts as tumor-suppressor and decelerates the progression of prostate cancer by transcriptional regulation of senescence- and inflammation-associated genes. This study opens avenues for novel treatment strategies that could impede disease progression and improve patient outcomes.

• Klíčová slova
• AP-1 transcription factors, Immune infiltration, JUN, Prostate cancer, SASP, Senescence,
• MeSH
• fosfohydroláza PTEN * genetika   metabolismus   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí * imunologie   MeSH
• nádory prostaty * patologie   genetika   metabolismus   MeSH
• progrese nemoci * MeSH
• protoonkogenní proteiny c-jun metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• sekreční fenotyp asociovaný se senescencí MeSH
• stanovení celkové genové exprese MeSH
• stárnutí buněk genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fosfohydroláza PTEN * MeSH
• protoonkogenní proteiny c-jun MeSH

Although the induction of senescence in cancer cells is a potent mechanism of tumor suppression, senescent cells remain metabolically active and may secrete a broad spectrum of factors that promote tumorigenicity in neighboring malignant cells. Here we show that androgen deprivation therapy (ADT), a widely used treatment for advanced prostate cancer, induces a senescence-associated secretory phenotype in prostate cancer epithelial cells, indicated by increases in senescence-associated β-galactosidase activity, heterochromatin protein 1β foci, and expression of cathepsin B and insulin-like growth factor binding protein 3. Interestingly, ADT also induced high levels of vimentin expression in prostate cancer cell lines in vitro and in human prostate tumors in vivo. The induction of the senescence-associated secretory phenotype by androgen depletion was mediated, at least in part, by down-regulation of S-phase kinase-associated protein 2, whereas the neuroendocrine differentiation of prostate cancer cells was under separate control. These data demonstrate a previously unrecognized link between inhibition of androgen receptor signaling, down-regulation of S-phase kinase-associated protein 2, and the appearance of secretory, tumor-promoting senescent cells in prostate tumors. We propose that ADT may contribute to the development of androgen-independent prostate cancer through modulation of the tissue microenvironment by senescent cells.

• MeSH
• androgenní receptory metabolismus   MeSH
• antagonisté androgenů farmakologie   MeSH
• beta-galaktosidasa metabolismus   MeSH
• down regulace účinky léků   MeSH
• fosfohydroláza PTEN metabolismus   MeSH
• IGFBP-3 metabolismus   MeSH
• kathepsin B metabolismus   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory prostaty genetika   metabolismus   patologie   MeSH
• proteiny asociované s kinázou S-fáze genetika   metabolismus   MeSH
• průtoková cytometrie MeSH
• RNA interference MeSH
• signální transdukce účinky léků   MeSH
• stárnutí buněk účinky léků   MeSH
• vimentin metabolismus   MeSH
• western blotting MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• androgenní receptory MeSH
• antagonisté androgenů MeSH
• AR protein, human MeSH Prohlížeč
• beta-galaktosidasa MeSH
• fosfohydroláza PTEN MeSH
• IGFBP-3 MeSH
• kathepsin B MeSH
• proteiny asociované s kinázou S-fáze MeSH
• vimentin MeSH