Inflammation and Prostate Cancer Development and Progression

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DESCRIPTION (provided by applicant): Data forming the foundation for a role for inflammation in prostate cancer comes from a variety of fields. Epidemiology studies show an increased incidence of prostate cancer associated with prostatitis and a decreased risk for individuals taking anti-inflammatory drugs. Notably, two-candidate familial prostate cancer genes code for proteins associated with the innate immune response, interferon inducible ribonuclease (RNASEL) and macrophage scavenger receptor-1 (MSR1). Also, the loss of glutathione S-transferase (GST) expression, which has been described in most prostate cancers, increases the susceptibility to mutations induced by oxygen radicals produced by inflammation. Further, inflammation induced prostatic intraepithelial atrophy (PIA) is hypothesized to be a precursor to the development of prostate cancer. Finally, IL-6 has been linked to prostate cancer growth. The multiplicity of associations between inflammation and prostate cancer are correlative but strongly implicate a relationship. Thus, establishment of models that will provide a system for defining mechanisms associated with inflammation-induced modulation of prostate cancer development and progression are needed. We have developed a genetically modified mouse model expressing a prostate specific model antigen,membrane bound ovalbumin (mOVA), prostate specific PTEN knockout generated by Cre/Loxp, and luciferase expression in prostate epithelial cells for imaging purposes (POETPTEN). The model was generated by crossing a prostate specific mOVA transgenic (POET-3) with the genetically modified PTEN knockout expressing luciferase (PTENfl/fl-luc). Preliminary data demonstrate in both POET-3 and POETPTEN demonstrate that inflammation is induced in both models. Studies in POET-3 show inflammation remains 84 days after initiation. Notably, significantly elevated prostate epithelial cell proliferation was observed in the inflamed prostate as late as the 84 day time point. Likewise, cytokine production remains elevated in the inflamed prostate 45 days after initiation, which is the latest evaluation time point. Because the prostate- specific PTEN null model represents various stages of prostate cancer progression, we are in a unique position to evaluate the impact of inflammation on disease progression in the combined POET-PTEN model. These data provide a basis for the hypothesis that prostate inflammation modulates tumor development and progression. Studies outlined in this application propose to characterize prostate inflammation in both a pre- neoplastic and a tumor environment and identify potential immunoregulatory elements present during inflammation. To this end the following specific aims are proposed: Aim 1. Characterize prostate cancer development and progression in the inflamed prostate; and Aim 2. Characterization of inflammatory cell infiltration during prostate inflammation in a pre-neoplastic (PTEN+/fl), tumor (PTENfllfl) and benign (PTEN+/+) mice. PUBLIC HEALTH RELEVANCE: The proposed studies introduce a novel model for evaluating the impact of inflammation on prostate cancer development. The studies proposed will determine the impact of inflammation on prostate cancer development and progression.