The role of prostate inflammation and fibrosis in lower urinary tract symptoms

Lower urinary tract symptoms (LUTS) in aging men are extremely common. They have historically been attributed to benign prostatic hyperplasia (BPH), enlargement of the prostate, and bladder outlet obstruction. However, recent studies have revealed acute and chronic inflammation to be highly associated with LUTS, correlated with prostatic enlargement, and implicated as a cause of prostatic fibrosis that contributes to bladder outlet obstruction. This review examines the evidence implicating inflammation and fibrosis in BPH/LUTS. It identifies potential mechanisms by which inflammation may drive nociceptive signaling as well as hyperplastic growth and fibrosis and identifies targets for pharmacological intervention. This is a promising area for research and development of novel therapies to prevent or more effectively treat LUTS in aging men

The Role of Pharmacology in Ureteral Physiology and Expulsive Therapy

Abstract. Research in the field of ureteral physiology and pharmacology has traditionally been directed toward relaxation of ureteral spasm as a mechanism of analgesia during painful ureteral obstruction, most often stone-induced episodes. However, interest in this field has expanded greatly in recent years with the expanded use of alpha-blocker therapy for inducing stone passage, a usage now termed "medical expulsive therapy". While most clinical reports involving expulsive therapy have focused on alpha receptor or calcium channel blockade, there are diverse studies investigating pharmacological ureteral relaxation with novel agents including cyclooxygenase inhibitors, small molecule beta receptor agonists, neurokinin antagonists, and phosphodiesterase inhibitors. In addition, cutting edge molecular biology research is revealing promising potential therapeutic targets aimed at specific molecular changes that occur during the acute obstruction that accompanies stone disease. The purpose of this report is to review the use of pharmacological agents as ureteral smooth muscle relaxants clinically, and to look into the future of expulsive therapy by reviewing the available literature of ureteral physiology and pharmacology research

Ras/ERK and PI3K/AKT signaling differentially regulate oncogenic ERG mediated transcription in prostate cells

The TMPRSS2/ERG gene rearrangement occurs in 50% of prostate tumors and results in expression of the transcription factor ERG, which is normally silent in prostate cells. ERG expression promotes prostate tumor formation and luminal epithelial cell fates when combined with PI3K/AKT pathway activation, however the mechanism of synergy is not known. In contrast to luminal fates, expression of ERG alone in immortalized normal prostate epithelial cells promotes cell migration and epithelial to mesenchymal transition (EMT). Migration requires ERG serine 96 phosphorylation via endogenous Ras/ERK signaling. We found that a phosphomimetic mutant, S96E ERG, drove tumor formation and clonogenic survival without activated AKT. S96 was only phosphorylated on nuclear ERG, and differential recruitment of ERK to a subset of ERG-bound chromatin associated with ERG-activated, but not ERG-repressed genes. S96E did not alter ERG genomic binding, but caused a loss of ERG-mediated repression, EZH2 binding and H3K27 methylation. In contrast, AKT activation altered the ERG cistrome and promoted expression of luminal cell fate genes. These data suggest that, depending on AKT status, ERG can promote either luminal or EMT transcription programs, but ERG can promote tumorigenesis independent of these cell fates and tumorigenesis requires only the transcriptional activation function

Coordinated induction of cell survival signaling in the inflamed microenvironment of the prostate

PURPOSE: Both prostate cancer and benign prostatic hyperplasia are associated with inflammatory microenvironments. Inflammation is damaging to tissues, but it is unclear how the inflammatory microenvironment protects specialized epithelial cells that function to proliferate and repair the tissue. The objective of this study is to characterize the cell death and cell survival response of the prostatic epithelium in response to inflammation. METHODS: We assessed induction of cell death (TNF, TRAIL, TWEAK, FasL) and cell survival factors (IGFs, hedgehogs, IL-6, FGFs, and TGFs) in inflamed and control mouse prostates by ELISA. Cell death mechanisms were determined by immunoblotting and immunofluorescence for cleavage of caspases and TUNEL. Survival pathway activation was assessed by immunoblotting and immunofluorescence for Mcl-1, Bcl-2, Bcl-XL, and survivin. Autophagy was determined by immunoblotting and immunofluorescence for free and membrane associated light chain 3 (LC-3). RESULTS: Cleavage of all four caspases was significantly increased during the first 2 days of inflammation, and survival protein expression was substantially increased subsequently, maximizing at 3 days. By 5 days of inflammation, 50% of prostatic epithelial cells expressed survivin. Autophagy was also evident during the recovery phase (3 days). Finally, immunofluorescent staining of human specimens indicates strong activation of survival proteins juxtaposed to inflammation in inflamed prostate specimens. CONCLUSIONS: The prostate responds to deleterious inflammation with induction of cell survival mechanisms, most notably survivin and autophagy, demonstrating a coordinated induction of survival factors that protects and expands a specialized set of prostatic epithelial cells as part of the repair and recovery process during inflammation

The common parasite Toxoplasma gondii induces prostatic inflammation and microglandular hyperplasia in a mouse model

BACKGROUND: Inflammation is the most prevalent and widespread histological finding in the human prostate, and associates with the development and progression of benign prostatic hyperplasia and prostate cancer. Several factors have been hypothesized to cause inflammation, yet the role each may play in the etiology of prostatic inflammation remains unclear. This study examined the possibility that the common protozoan parasite Toxoplasma gondii induces prostatic inflammation and reactive hyperplasia in a mouse model. METHODS: Male mice were infected systemically with T. gondii parasites and prostatic inflammation was scored based on severity and focality of infiltrating leukocytes and epithelial hyperplasia. We characterized inflammatory cells with flow cytometry and the resulting epithelial proliferation with bromodeoxyuridine (BrdU) incorporation. RESULTS: We found that T. gondii infects the mouse prostate within the first 14 days of infection and can establish parasite cysts that persist for at least 60 days. T. gondii infection induces a substantial and chronic inflammatory reaction in the mouse prostate characterized by monocytic and lymphocytic inflammatory infiltrate. T. gondii-induced inflammation results in reactive hyperplasia, involving basal and luminal epithelial proliferation, and the exhibition of proliferative inflammatory microglandular hyperplasia in inflamed mouse prostates. CONCLUSIONS: This study identifies the common parasite T. gondii as a new trigger of prostatic inflammation, which we used to develop a novel mouse model of prostatic inflammation. This is the first report that T. gondii chronically encysts and induces chronic inflammation within the prostate of any species. Furthermore, T. gondii-induced prostatic inflammation persists and progresses without genetic manipulation in mice, offering a powerful new mouse model for the study of chronic prostatic inflammation and microglandular hyperplasia

Toll-like receptor 4 signaling activates ERG function in prostate cancer and provides a therapeutic target

The TMPRSS2-ERG gene fusion and subsequent overexpression of the ERG transcription factor occurs in ∼50% of prostate tumors, making it the most common abnormality of the prostate cancer genome. While ERG has been shown to drive tumor progression and cancer-related phenotypes, as a transcription factor it is difficult to target therapeutically. Using a genetic screen, we identified the toll-like receptor 4 (TLR4) signaling pathway as important for ERG function in prostate cells. Our data confirm previous reports that ERG can transcriptionally activate TLR4 gene expression; however, using a constitutively active ERG mutant, we demonstrate that the critical function of TLR4 signaling is upstream, promoting ERG phosphorylation at serine 96 and ERG transcriptional activation. The TLR4 inhibitor, TAK-242, attenuated ERG-mediated migration, clonogenic survival, target gene activation and tumor growth. Together these data indicate a mechanistic basis for inhibition of TLR4 signaling as a treatment for ERG-positive prostate cancer

Anti-tumor activity and mechanistic characterization of APE1/Ref-1 inhibitors in bladder cancer

Bladder cancer is the ninth most common cause of cancer-related deaths worldwide. Although cisplatin is used routinely in treating bladder cancer, refractory disease remains lethal for many patients. The recent addition of immunotherapy has improved patient outcomes; however, a large cohort of patients does not respond to these treatments. Therefore, identification of innovative molecular targets for bladder cancer is crucial. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in both DNA repair and activation of transcription factors through reduction-oxidation (redox) regulation. High APE1/Ref-1 expression is associated with shorter patient survival time in many cancer types. In this study, we found high APE1/Ref-1 expression in human bladder cancer tissue relative to benign urothelium. Inhibition of APE1/Ref-1 redox signaling using APE1/Ref-1-specific inhibitors attenuates bladder cancer cell proliferation in monolayer, in three-dimensional cultures, and in vivo. This inhibition corresponds with an increase in apoptosis and decreased transcriptional activity of NF-κB and STAT3, transcription factors known to be regulated by APE1/Ref-1, resulting in decreased expression of downstream effectors survivin and Cyclin D1 in vitro and in vivo. We also demonstrate that in vitro treatment of bladder cancer cells with APE1/Ref-1 redox inhibitors in combination with standard-of-care chemotherapy cisplatin is more effective than cisplatin alone at inhibiting cell proliferation. Collectively, our data demonstrate that APE1/Ref-1 is a viable drug target for the treatment of bladder cancer, provide a mechanism of APE1/Ref-1 action in bladder cancer cells, and support the use of novel redox-selective APE1/Ref-1 inhibitors in clinical studies. SIGNIFICANCE: This work identifies a critical mechanism for APE1/Ref-1 in bladder cancer growth and provides compelling preclinical data using selective redox activity inhibitors of APE1/Ref-1 in vitro and in vivo

Phosphatase and Tensin Homologue: Novel Regulation by Developmental Signaling

Phosphatase and tensin homologue (PTEN) is a critical cell endogenous inhibitor of phosphoinositide signaling in mammalian cells. PTEN dephosphorylates phosphoinositide trisphosphate (PIP3), and by so doing PTEN has the function of negative regulation of Akt, thereby inhibiting this key intracellular signal transduction pathway. In numerous cell types, PTEN loss-of-function mutations result in unopposed Akt signaling, producing numerous effects on cells. Numerous reports exist regarding mutations in PTEN leading to unregulated Akt and human disease, most notably cancer. However, less is commonly known about nonmutational regulation of PTEN. This review focuses on an emerging literature on the regulation of PTEN at the transcriptional, posttranscriptional, translational, and posttranslational levels. Specifically, a focus is placed on the role developmental signaling pathways play in PTEN regulation; this includes insulin-like growth factor, NOTCH, transforming growth factor, bone morphogenetic protein, wnt, and hedgehog signaling. The regulation of PTEN by developmental mediators affects critical biological processes including neuronal and organ development, stem cell maintenance, cell cycle regulation, inflammation, response to hypoxia, repair and recovery, and cell death and survival. Perturbations of PTEN regulation consequently lead to human diseases such as cancer, chronic inflammatory syndromes, developmental abnormalities, diabetes, and neurodegeneration

Ras/ERK and PI3K/AKT signaling differentially regulate oncogenic ERG mediated transcription in prostate cells.

The TMPRSS2/ERG gene rearrangement occurs in 50% of prostate tumors and results in expression of the transcription factor ERG, which is normally silent in prostate cells. ERG expression promotes prostate tumor formation and luminal epithelial cell fates when combined with PI3K/AKT pathway activation, however the mechanism of synergy is not known. In contrast to luminal fates, expression of ERG alone in immortalized normal prostate epithelial cells promotes cell migration and epithelial to mesenchymal transition (EMT). Migration requires ERG serine 96 phosphorylation via endogenous Ras/ERK signaling. We found that a phosphomimetic mutant, S96E ERG, drove tumor formation and clonogenic survival without activated AKT. S96 was only phosphorylated on nuclear ERG, and differential recruitment of ERK to a subset of ERG-bound chromatin associated with ERG-activated, but not ERG-repressed genes. S96E did not alter ERG genomic binding, but caused a loss of ERG-mediated repression, EZH2 binding and H3K27 methylation. In contrast, AKT activation altered the ERG cistrome and promoted expression of luminal cell fate genes. These data suggest that, depending on AKT status, ERG can promote either luminal or EMT transcription programs, but ERG can promote tumorigenesis independent of these cell fates and tumorigenesis requires only the transcriptional activation function