Intraepithelial lymphocytes in relation to NIH category IV prostatitis in autopsy prostate

Membrane-derived particles shed by PSMA-positive cells function as pro-angiogenic stimuli in tumors

Cell membrane-derived particles (Mp) are rounded membrane-enclosed particles that are shed from tumor cells. Mp are formed from tumor membranes and are capable of tumor targeting and immunotherapeutic agents because they share membrane homology with parental cells; thus, they are under consideration as a drug delivery vehicle. Prostate-specific membrane antigen (PSMA), a transmembrane glycoprotein with enzymatic functionality, is highly expressed in Mp and extracellular vesicles (EV) from prostate cancer (PCa) with poor clinical prognosis. Although PSMA expression was previously shown in EV and Mp isolated from cell lines and from the blood of patients with high-grade PCa, no pathophysiological effects have been linked to PCa-derived Mp. Here, we compared Mp from PSMA-expressing (PSMA-Mp) and PSMA-non-expressing (WT-Mp) cells side by side in vitro and in vivo. PSMA-Mp can transfer PSMA and new phenotypic characteristics to the tumor microenvironment. The consequence of PSMA transfer to cells and increased secretion of vascular endothelial growth factor-A (VEGF-A), pro-angiogenic and pro-lymphangiogenic mediators, with increased 4E binding protein 1 (4EBP-1) phosphorylation.

Histopathology of nonspecific granulomatous prostatitis with special reference to eosinophilic epithelial metaplasia: Pathophysiologic, diagnostic and differential diagnostic correlations

Background

Recently, we publish two case reports about association of nonspecific granulomatous prostatitis (NSGP) and eosinophilic metaplasia (EM) in benign prostatic epithelium. There is no investigation of large series of this association in medical literature. Aim of the current study is to investigate the frequency of association of NSGP and prostatic EM in a large series of cases and their relationship with the basic prostate pathology: benign prostatic hyperplasia (BPH), National Institutes of Health-category IV prostatitis (so-called histologic prostatitis (HP)), and prostatic adenocarcinoma (PCa).

Materials and Methods

A retrospective record review for NSGP was performed on a total of 2366 prostatic specimens of all types of material. All cases of NSGP were reviewed for the presence of EM, BPH, and HP. NSGP with EM-cases and control cases with high grade PCa with endocrine differentiation (so-called Paneth cell-like changes) were evaluated immunohistochemically.

Results

NSGP was found in nine cases (0.38%). EM was detected in benign perigranulomatous secretory epithelial cells in 100% of cases with NSGP and were closely associated with BPH and HP. Immunohistochemically, in 55.5% of cases with EM, there was weak focal apical false-positive staining for p504s.

Conclusion

EM is a very common lesion in NSGP and reflects histologically a nonspecific cellular response, connected with repeated inflammation, in close relation with BPH and HP. We speculate that EM might serve as a morphological precursor of the immunologic phase of NSGP. This constant morphological finding could facilitate the histopathological differential diagnosis of NSGP with other types of granulomatous prostatitis and high grade PCa with or without endocrine differentiation.

Experimental autoimmune prostatitis: different antigens induction and antigen-specific therapy

PURPOSE

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has uncertain etiology and lacks effective treatment. Autoimmunity is an important pathogeny, and experimental autoimmune prostatitis (EAP) models have long been used for studying CP/CPPS. This review presents the detailed current knowledge of EAP models based on evaluation criteria aspects to provide a tool for model selection in pathogenesis studies and therapeutic drug screening.

METHODS

We extensively searched the published literature on CP/CPPS and different antigen-induced EAP models focusing on the histopathology, clinical-related phenotypes, and biochemical indicators. We also cover the changes in the prostate function and other organs in EAP. Finally, we try to get some insights about antigen-based therapeutic approaches for CP/CPPS.

RESULTS

Several inciting autoantigens were reported in EAP, including male accessory gland extracts, prostate extracts (PE), prostatic steroid-binding protein, prostatic spermine-binding protein (p25), prostatic acid phosphatase, seminal vesicle secretory protein 2, and T2 peptide. All of these models mimicked histological prostatitis, however only p25- and T2-induced models developed both pelvic pain and voiding behaviors. PE immunization is the most widely used method. Diminished fertility and mental health disorders can be found in PE model. Oral and intravenous T2 peptide have been studied for antigen-specific therapy and achieved preliminary progress in EAP models.

CONCLUSIONS

PE-induced model is the most commonly used, while T2- or p25-model could serve as a promising CP/CPPS model. Antigen-specific therapy in CP/CPPS deserves further study.

Prostate immunology: A challenging puzzle

Mucosal immunity defines the relationship of surfaces in contact with the environment and integrates diverse tissues such as epidermis, gum, nose, gut, uterus and prostate with the immune system. Although considered part of a system, each mucosa presents specific immune features beyond the barrier and secretory functions. Information regarding the mucosal immunology of the male reproductive tract and the prostate gland in particular is scarce. In this review, we approach the prostate as an epithelial barrier and as part of the mucosal immune system. Finally, we also raise a series of questions that will improve the understanding of this gland, its role in reproduction and its sensitivity/resistance to disease.

Human microbiome and prostate cancer development: current insights into the prevention and treatment

The huge communities of microorganisms that symbiotically colonize humans are recognized as significant players in health and disease. The human microbiome may influence prostate cancer development. To date, several studies have focused on the effect of prostate infections as well as the composition of the human microbiome in relation to prostate cancer risk. Current studies suggest that the microbiota of men with prostate cancer significantly differs from that of healthy men, demonstrating that certain bacteria could be associated with cancer development as well as altered responses to treatment. In healthy individuals, the microbiome plays a crucial role in the maintenance of homeostasis of body metabolism. Dysbiosis may contribute to the emergence of health problems, including malignancy through affecting systemic immune responses and creating systemic inflammation, and changing serum hormone levels. In this review, we discuss recent data about how the microbes colonizing different parts of the human body including urinary tract, gastrointestinal tract, oral cavity, and skin might affect the risk of developing prostate cancer. Furthermore, we discuss strategies to target the microbiome for risk assessment, prevention, and treatment of prostate cancer.

A review on the interactions between the tumor microenvironment and androgen receptor signaling in prostate cancer

Prostate cancer growth is controlled by androgen receptor signaling via both androgen-dependent and androgen-independent pathways. Furthermore, the prostate is an immune competent organ with inflammatory changes both within the systemic and local environment contributing to the reprogramming of the prostatic epithelium with consistently elevated lymphocyte infiltration and proinflammatory cytokines being found in prostate cancer. The crosstalk between the tumor microenvironment and androgen receptor signaling is complex with both protumorigenic and antitumorigenic roles observed. However, despite an increase in immune checkpoint inhibitors and inflammatory signaling blockades available for a range of cancer types, we are yet to see substantial progress in the treatment of prostate cancer. Therefore, this review aims to summarize the tumor microenvironment and its impact on androgen receptor signaling in prostate cancer.

The inflammatory microenvironment and microbiome in prostate cancer development

Chronic inflammation promotes the development of several types of solid cancers and might contribute to prostate carcinogenesis. This hypothesis partly originates in the frequent observation of inflammatory cells in the prostate microenvironment of adult men. Inflammation is associated with putative prostate cancer precursor lesions, termed proliferative inflammatory atrophy. Inflammation might drive prostate carcinogenesis via oxidative stress and generation of reactive oxygen species that induce mutagenesis. Additionally, inflammatory stress might cause epigenetic alterations that promote neoplastic transformation. Proliferative inflammatory atrophy is enriched for proliferative luminal epithelial cells of intermediate phenotype that might be prone to genomic alterations leading to prostatic intraepithelial neoplasia and prostate cancer. Studies in animals suggest that inflammatory changes in the prostate microenvironment contribute to reprogramming of prostate epithelial cells, a possible step in tumour initiation. Prostatic infection, concurrent with epithelial barrier disruption, might be a key driver of an inflammatory microenvironment; the discovery of a urinary microbiome indicates a potential source of frequent exposure of the prostate to a diverse number of microorganisms. Hence, current evidence suggests that inflammation and atrophy are involved in prostate carcinogenesis and suggests a role for the microbiome in establishing an inflammatory prostate microenvironment that might promote prostate cancer development and progression.