Prostate Tumor Development Research Articles

Exosomes That Have Different Cellular Origins Followed by the Impact They Have on Prostate Tumor Development in the Tumor Microenvironment.

Prostate cancer (PCa) is the most common urinary tumor with the highest incidence rate and the second among the leading causes of death worldwide for adult males. In the worldwide cancer incidence rate, PCa is on the increase. The cancerous cells in the prostate and cells in the microenvironment surrounding the tumor communicate through signal transduction, which is crucial for the development and spread of PCa. Exosomes are nanoscale vesicles released into body fluids by various cells that can aid intercellular communication by releasing nucleic acids and proteins. Exosomes published by different types of cells in the tumor microenvironment can have varying impacts on the proliferation and growth of tumor cells via various signaling pathways, modes of action, and secreted cytokines. The main purpose of this review is to describe the effects of different cell-derived exosomes in the tumor microenvironment of PCa on the progression of tumor cells, as well as to summarize and discuss the prospects for the application of exosomes in the treatment and diagnosis of PCa.

Sensitivity of magnetic resonance elastography to extracellular matrix and cell motility in human prostate cancer cell line-derived xenograft models

Prostate cancer (PCa) is a significant health problem in the male population of the Western world. Magnetic resonance elastography (MRE), an emerging medical imaging technique sensitive to mechanical properties of biological tissues, detects PCa based on abnormally high stiffness and viscosity values. Yet, the origin of these changes in tissue properties and how they correlate with histopathological markers and tumor aggressiveness are largely unknown, hindering the use of tumor biomechanical properties for establishing a noninvasive PCa staging system.To infer the contributions of extracellular matrix (ECM) components and cell motility, we investigated fresh tissue specimens from two PCa xenograft mouse models, PC3 and LNCaP, using magnetic resonance elastography (MRE), diffusion-weighted imaging (DWI), quantitative histology, and nuclear shape analysis. Increased tumor stiffness and impaired water diffusion were observed to be associated with collagen and elastin accumulation and decreased cell motility. Overall, LNCaP, while more representative of clinical PCa than PC3, accumulated fewer ECM components, induced less restriction of water diffusion, and exhibited increased cell motility, resulting in overall softer and less viscous properties. Taken together, our results suggest that prostate tumor stiffness increases with ECM accumulation and cell adhesion - characteristics that influence critical biological processes of cancer development.MRE paired with DWI provides a powerful set of imaging markers that can potentially predict prostate tumor development from benign masses to aggressive malignancies in patients. Statement of significanceXenograft models of human prostate tumor cell lines, allowing correlation of microstructure-sensitive biophysical imaging parameters with quantitative histological methods, can be investigated to identify hallmarks of cancer.

TLR9 Monotherapy in Immune-Competent Mice Suppresses Orthotopic Prostate Tumor Development.

Prostate cancer is ranked second in the world for cancer-related deaths in men, highlighting the lack of effective therapies for advanced-stage disease. Toll-like receptors (TLRs) and immunity have a direct role in prostate cancer pathogenesis, but TLR9 has been reported to contribute to both the progression and inhibition of prostate tumorigenesis. To further understand this apparent disparity, we have investigated the effect of TLR9 stimulation on prostate cancer progression in an immune-competent, syngeneic orthotopic mouse model of prostate cancer. Here, we utilized the class B synthetic agonist CPG-1668 to provoke a TLR9-mediated systemic immune response and demonstrate a significant impairment of prostate tumorigenesis. Untreated tumors contained a high abundance of immune-cell infiltrates. However, pharmacological activation of TLR9 resulted in smaller tumors containing significantly fewer M1 macrophages and T cells. TLR9 stimulation of tumor cells in vitro had no effect on cell viability or its downstream transcriptional targets, whereas stimulation in macrophages suppressed cancer cell growth via type I IFN. This suggests that the antitumorigenic effects of CPG-1668 were predominantly mediated by an antitumor immune response. This study demonstrated that systemic TLR9 stimulation negatively regulates prostate cancer tumorigenesis and highlights TLR9 agonists as a useful therapeutic for the treatment of prostate cancer.

Epigenetic regulation of androgen dependent and independent prostate cancer.

Prostate cancer is one of the most common malignancies among men worldwide. Besides genetic alterations, epigenetic modulations including DNA methylation, histone modifications and miRNA mediated alteration of gene expression are the key driving forces for the prostate tumor development and cancer progression. Aberrant expression and/or the activity of the epigenetic modifiers/enzymes, results in aberrant expression of genes involved in DNA repair, cell cycle regulation, cell adhesion, apoptosis, autophagy, tumor suppression and hormone response and thereby disease progression. Altered epigenome is associated with prostate cancer recurrence, progression, aggressiveness and transition from androgen-dependent to androgen-independent phenotype. These epigenetic modifications are reversible and various compounds/drugs targeting the epigenetic enzymes have been developed that are effective in cancer treatment. This chapter focuses on the epigenetic alterations in prostate cancer initiation and progression, listing different epigenetic biomarkers for diagnosis and prognosis of the disease and their potential as therapeutic targets. This chapter also summarizes different epigenetic drugs approved for prostate cancer therapy and the drugs available for clinical trials.

NKX3.1 Expression Contributes to Epithelial-Mesenchymal Transition of Prostate Cancer Cells.

Studies demonstrate that inflammation synergizes with high-grade aggressive prostate tumor development and ultimately metastatic spread, in which a lot of work has been done in recent years. However, the clear mechanism of inflammation inciting prostate cancer remains largely uncharacterized. Our previous study has shown that the conditioned media (CM)-mediated LNCaP cell migration is partially correlated with the loss of expression of the tumor suppressor NKX3.1. Here, we continue to investigate the inflammation-mediated migration of prostate cancer cells, and the role of NKX3.1 in this process to gain insights into cell migration-related changes comprehensively. Earlier, the model of inflammation in the tumor microenvironment have been optimized by our research group; here, we continue to investigate the time-dependent effect of CM exposure together with NKX3.1 changes, in which we observed that these changes play important roles in gaining heterogeneous epithelial-to-mesenchymal transition (EMT) phenotype. Hence, this is an important parameter of tumor progression; we depleted NKX3.1 expression using the CRISPR/Cas9 system and examined the migrating cell clusters after exposure to inflammatory cytokines. We found that the migrated cells clearly demonstrate reversible loss of E-cadherin expression, which is consistent with subsequent vimentin expression alterations in comparison to control cells. Moreover, the data suggest that the AR-mediated transcriptional program also contributes to mesenchymal-to-epithelial transition (MET) in prostate cancer progression. Furthermore, the quantitative proteomic analysis showed that migrated subpopulations from the same cell line presented different phenotypes in which the proteins overexpressed are involved in cell metabolism and RNA processing. According to KEGG pathway analysis, the ABC transporters were found to be the most significant. Thus, the dynamic process of cellular migration favors diverse genetic compositions under changing tumor microenvironments. The different levels of invasiveness are supported by shifting the cells in between these EMT and MET phenotypes.

Abstract A028: Dissecting the role of cellular senescence in prostate cancer initiation and immune suppression

Abstract Prostate cancer is the most common malignancy and the second leading cause of cancer-related death in American men. Although many disease cases remain latent for decades, others progress to malignant prostate cancer with high rates of mortality. The molecular underpinnings driving malignancy are still poorly understood, and there is an urgent need to identify mechanisms and informative biomarkers of disease progression. Using the Pb-Cre+; Ptenfl/fl (CP) mouse model, we and others found that Pten genomic loss, a common occurrence in human prostate cancer, leads to induction of cellular senescence, senescence-associated inflammation, and immune suppression during tumor onset. Similarly, senescence markers have also been identified in benign and early prostate cancer lesions in humans. This suggests that senescence may play a yet uncharacterized functional role in prostate tumorigenesis. Cellular senescence is a damage-induced pathway leading to durable growth arrest and has long been considered a potent tumor suppressive mechanism that limits the ability of pre-malignant cells to proliferate and develop into malignant tumors. However, recent findings suggest that the accumulation of senescent cells can paradoxically lead to chronic inflammation that fosters an environment for eventual tumor development and progression through the induction of growth and inflammatory factors collectively known as the senescence-associated secretory phenotype (SASP). Thus, it remains unclear whether senescence or specific senescent cell populations block or rather promote prostate tumor development. Leveraging the CP prostate cancer mouse model and genetic tools to track senescent cells, we observed that markers of senescence (SA-β-gal, p16, Bcl2) and the inflammatory SASP (NF-𝜅B, IL-1b, CXCL1, CSF-1) were not only present in early prostate intraepithelial neoplasia (PIN) lesions but remained elevated following adenocarcinoma development and progression, and could be found in both epithelial cells as well as other immune and stromal populations. Expression of the canonical senescence marker p16 also correlated with disease progression in human prostate cancer samples. Moreover, senescent cell accumulation was associated with a reduction in cytotoxic lymphocytes and an influx of suppressive myeloid populations that we and others have previously shown contribute to prostate cancer progression. Senolytic approaches to eliminate these senescent cell populations reduced progression to adenocarcinoma and remodeled the immune system to reverse myeloid-mediated immune suppression and activate cytotoxic lymphocyte immunity. Together, our preliminary results suggest that senescence might contribute to prostate cancer initiation and progression, and that removal of senescent cells could delay tumor onset and reverse prostate cancer immune suppression. Citation Format: Lin Zhou, Jarin Snyder, Katherine C. Murphy, Kelly D. DeMarco, Sachliv Chana, Karl Simin, Zhong Jiang, Marcus Ruscetti. Dissecting the role of cellular senescence in prostate cancer initiation and immune suppression [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A028.

Molecular evaluation of human papillomavirus as an oncogenic biomarker in prostate cancer.

Prostate cancer (PCa) is one of the most common tumors in men, regardless of ethnicity and demographics. In many risk factors causing PCa, genes and viral infections are strong candidates for the development of prostate tumors. Indeed, tissue infections of PCa have been reported by the presence of several types of viruses including Human Papillomaviruses (HPV). the present study was planned to determine whether HPV DNA could be detected in the blood of known men with prostate cancer and to assess the potential association between HPV infection and clinico-pathological characteristics of the patients. In order to achieve our objectives, 150 liquid blood samples were taken from Moroccan patients, 100 patients with PCa, and 50 control cases. The viral DNA was extracted, calibrated and the target genes were amplified by PCR using specific primers and the use of 2% agarose gel with visualization under UV. Of the 100 samples tested, (10%) were infected with HPV), However, none of the control cases were infected with HPV. The analysis of the data made it possible to establish a correlation between the frequency of the viral infection of the human papilloma and the tumoral criteria. Therefore, this study strengthens the potential role of HPV as a cofactor in prostate cancer development, and we propose that infection with this virus may be involved in the development of PCa metastases.

Abstract 1243: RON receptor signaling enhances prostate cancer metastasis in Hi-Myc mice

Abstract Prostate cancer (PCa) is the second leading cause of cancer mortality among men globally. Death from PCa is typically due to the lack of effective treatments for advanced forms of prostate cancers including castration-resistant prostate cancer (CRPC) and metastatic prostate cancers (mPCa). Distantly metastasized cancers drop the 5-year survival rate from 98% to 30%. Understanding the intrinsic and extrinsic mechanisms that lead to the development of these advanced prostate cancers could improve treatment options. The RON receptor tyrosine kinase is a cell surface receptor, which is activated by growth factor ligands (HGFL or Gas6), which binding promotes several cancer phenotypes in various cancers including prostate cancer. Our laboratory has shown that RON is overexpressed in 86% of primary and 100% of metastatic human prostate cancers compared to normal prostate tissue. Additionally, we have shown that RON overexpression in the prostates of mice can induce Prostatic intraepithelial neoplasia (PIN) lesions, adenocarcinoma, and increases several cancer phenotypes including proliferation, cell survival, metastasis, and increased recruitment of tumor-associated macrophages. However, we have yet to explore the effect of RON on prostate cancer metastasis. We hypothesize that RON expression enhances metastasis by promoting an increase in the amount of disseminating prostate cancer cells. To test this hypothesis, the Hi-Myc mouse model has been employed. The MYC gene is one of the most dysregulated genes in prostate cancers and Myc expression has been detected in the early stages of prostate cancer development, PIN lesion, and all later stages of prostate cancer. Additionally, the Hi-Myc model is clinically relevant as prostate tumor development in this model is similar to that in humans in regard to progression from PIN lesions to adenocarcinoma. From the Hi-Myc model, we have generated two additional genetic modifications within prostate epithelial cells: 1) Hi-Myc mice with prostate-specific RON overexpression (OE) and 2) Hi-Myc mice with prostate-specific RON loss (ΔEpi). In this study we report that a lack of prostate RON expression diminishes adenocarcinoma development and metastasis within the Hi-Myc mouse model. Moreover, RON overexpression promotes the development of metastatic adenocarcinoma that was not observed in the prostates from Hi-Myc control mice. These studies suggest that RON expression supports the advancement of primary tumors to metastatic prostate cancer within the Hi-Myc mouse models. Therefore, future directions include determining the signaling pathways driven by RON that promotes this metastatic phenotype in both castration-sensitive and resistant tumors. Citation Format: Angelle D. Jones, Carissa Lester, Susan E. Waltz. RON receptor signaling enhances prostate cancer metastasis in Hi-Myc mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1243.

Abstract 7: AGS3 depletion promotes tumorigenesis in a murine model of lung cancer

Abstract Activator of G-protein Signaling 3 (AGS3/GPSM1) is a receptor independent activator of G-protein signaling that couples to Gα subunits of the heterotrimeric G-protein to mediate cellular functions. It was previously shown that AGS3 modulates prostate tumor development. In this study we investigate the role of AGS3 in the onset of lung cancer. To that end, we used a murine model of Lung Lewis Carcinoma (LLC) in mice deficient in AGS3 expression (AGS3-/-) relative to wild-type animals (AGS3+/+). AGS3-/- mice exhibited a significant increase in LLC tumor growth relative to AGS3+/+ mice. Immunohistochemical analysis of the tumors also revealed a significant increase in microvessels density in AGS3-/- tumors. FACS analysis of tumor infiltrating leukocytes also showed a significant decrease in lymphocyte recruitment in AGS3-/- tumor microenvironment (TME) relative to AGS3+/+ mice. The decrease leukocytes recruitment in AGS3-/- xenografts correlated with a marked decrease in chemokines expression in the TME. Taken together, these results indicate that AGS3 modulates LLC tumor development and progression. Citation Format: Timothy O. Adekoya, Nikia Smith, Ricardo M. Richardson. AGS3 depletion promotes tumorigenesis in a murine model of lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 7.

Polymorphisms in the gene encoding CYP1A2 influence prostate cancer risk and progression.

The role of the cytochrome P450 1A2 (CYP1A2) rs2472299, rs2470890 and rs11072508 polymorphisms in prostate cancer risk, disease progression and tumour development remains unclear. The potential associations of these three CYP1A2 polymorphisms and haplotypes with prostate cancer susceptibility and its clinicopathological characteristics were therefore investigated. The present case-control study consisted of 522 patients with prostate cancer and 554 healthy controls. High-resolution melting analysis was used to determine the CYP1A2 polymorphisms. No significant association in prostate cancer risk was seen for CYP1A2 rs2472299 and rs11072508. However, a significantly decreased risk of prostate cancer was found for CYP1A2 rs2470890 [odds ratio (OR), 0.67; P=0.02] in the recessive model. After analysis of the associations of clinical status and these three CYP1A2 polymorphisms, the CYP1A2 rs2470890 and rs11072508 polymorphisms showed a positive association with a higher Gleason score (rs2470890 OR, 1.36, P=0.04 in the allelic model; rs11072508 OR, 1.37, P=0.04 in the allelic model and OR, 1.60, P=0.03 in the dominant model). All three polymorphisms showed a significant positive association with pathological T stage in the additive, allelic and dominant genetic models (P<0.05). Haplotype analysis revealed that the most common haplotypes 'GTT' and 'ACC' were significantly associated with pathological T stages 3 and 4 (OR, 0.62; P=0.02 and OR, 1.54; P=0.03, respectively). A significant association was found between the 'GTT' haplotype and the Gleason score (OR, 0.71; P=0.03). In conclusion, these CYP1A2 polymorphisms and haplotypes have the potential to predict prostate cancer disease progression.

CHD6 promotes broad nucleosome eviction for transcriptional activation in prostate cancer cells.

Despite being a member of the chromodomain helicase DNA-binding protein family, little is known about the exact role of CHD6 in chromatin remodeling or cancer disease. Here we show that CHD6 binds to chromatin to promote broad nucleosome eviction for transcriptional activation of many cancer pathways. By integrating multiple patient cohorts for bioinformatics analysis of over a thousand prostate cancer datasets, we found CHD6 expression elevated in prostate cancer and associated with poor prognosis. Further comprehensive experiments demonstrated that CHD6 regulates oncogenicity of prostate cancer cells and tumor development in a murine xenograft model. ChIP-Seq for CHD6, along with MNase-Seq and RNA-Seq, revealed that CHD6 binds on chromatin to evict nucleosomes from promoters and gene bodies for transcriptional activation of oncogenic pathways. These results demonstrated a key function of CHD6 in evicting nucleosomes from chromatin for transcriptional activation of prostate cancer pathways.

Stromal androgen signaling acts as tumor niches to drive prostatic basal epithelial progenitor-initiated oncogenesis

The androgen receptor (AR)-signaling pathways are essential for prostate tumorigenesis. Although significant effort has been devoted to directly targeting AR-expressing tumor cells, these therapies failed in most prostate cancer patients. Here, we demonstrate that loss of AR in stromal sonic-hedgehog Gli1-lineage cells diminishes prostate epithelial oncogenesis and tumor development using in vivo assays and mouse models. Single-cell RNA sequencing and other analyses identified a robust increase of insulin-like growth factor (IGF) binding protein 3 expression in AR-deficient stroma through attenuation of AR suppression on Sp1-regulated transcription, which further inhibits IGF1-induced Wnt/β-catenin activation in adjacent basal epithelial cells and represses their oncogenic growth and tumor development. Epithelial organoids from stromal AR-deficient mice can regain IGF1-induced oncogenic growth. Loss of human prostate tumor basal cell signatures reveals in basal cells of stromal AR-deficient mice. These data demonstrate a distinct mechanism for prostate tumorigenesis and implicate co-targeting stromal and epithelial AR-signaling for prostate cancer.

Deletion of monoamine oxidase A in a prostate cancer model enhances anti-tumor immunity through reduced immune suppression

We have previously shown that monoamine oxidase A (MAO A) mediates prostate cancer growth and metastasis. Further, MAO A/Pten double knockout (DKO) mice were generated and demonstrated that the deletion of MAO A delayed prostate tumor development in the Pten knockout mouse model of prostate adenocarcinoma. Here, we investigated its effect on immune cells in the tumor microenvironment in MAO A/Pten DKO mouse model. Our results shows that Paraffin embedded prostate tissues from MAO A/Pten DKO mice had elevated markers of immune stimulation (CD8+ cytotoxic T cells, granzyme B, and IFNγ) and decreased expression of markers of immune suppression (FoxP3, CD11b, HIF-1-alpha, and arginase 1) compared to parental Pten knockouts (MAO A wildtype). CD11b+ myeloid derived suppressor cells (MDSC) were the primary immunosuppressive cell types in these tumors. The data suggest that deletion of MAO A reduces immune suppression in prostate tumors to enhance antitumor immunity in prostate cancer. Thus, MAO A inhibitor may alleviate immune suppression, increase the antitumor immune response and be used for cancer immunotherapy.

Dual Effect of Tryptamine on Prostate Cancer Cell Growth Regulation: A Pilot Study.

Abnormal tryptophan metabolism is linked to cancer and neurodegenerative diseases, and tryptophan metabolites have been reported as potential prostate cancer (PCa) biomarkers. However, little is known about the bioactivities of tryptophan metabolites on PCa cell growth. In this study, MTT and transwell assays were used to study the cytotoxicities of 13 major tryptophan metabolites on PCa and normal prostate epithelial cell lines. Ultraperformance liquid chromatography–high resolution mass spectrometry (UPLC–HRMS) was used to analyze metabolic changes in cells treated with tryptamine. Flow cytometry, confocal imaging, and Western blot were used to test the apoptosis induced by tryptamine. It was shown that tryptamine had obvious inhibitory effects on PCa cell lines PC-3 and LNCaP, stronger than those on the normal prostate cell line RWPE-1. Tryptamine was further shown to induce apoptosis and inhibit PC-3 cell migration. Metabolic changes including amino acid metabolism related to cell proliferation and metastasis were found in PC-3 cells treated with tryptamine. Furthermore, a PC-3 xenograft mouse model was used to study the effect of tryptamine in vivo. The intratumoral injection of tryptamine was demonstrated to significantly reduce the tumor growth and tumor sizes in vivo; however, intraperitoneal treatment resulted in increased tumor growth. Such dual effects in vivo advanced our understanding of the bioactivity of tryptamine in regulating prostate tumor development, in addition to its major role as a neuromodulator.

Aberrant androgen action in prostatic progenitor cells induces oncogenesis and tumor development through IGF1 and Wnt axes

Androgen/androgen receptor (AR) signaling pathways are essential for prostate tumorigenesis. However, the fundamental mechanisms underlying the AR functioning as a tumor promoter in inducing prostatic oncogenesis still remain elusive. Here, we demonstrate that a subpopulation of prostatic Osr1 (odd skipped-related 1)-lineage cells functions as tumor progenitors in prostate tumorigenesis. Single cell transcriptomic analyses reveal that aberrant AR activation in these cells elevates insulin-like growth factor 1 (IGF1) signaling pathways and initiates oncogenic transformation. Elevating IGF1 signaling further cumulates Wnt/β-catenin pathways in transformed cells to promote prostate tumor development. Correlations between altered androgen, IGF1, and Wnt/β-catenin signaling are also identified in human prostate cancer samples, uncovering a dynamic regulatory loop initiated by the AR through prostate cancer development. Co-inhibition of androgen and Wnt-signaling pathways significantly represses the growth of AR-positive tumor cells in both ex-vivo and in-vivo, implicating co-targeting therapeutic strategies for these pathways to treat advanced prostate cancer.

SIRT1 inhibition-induced senescence as a strategy to prevent prostate cancer progression.

Emerging evidence suggests an important role for SIRT1, a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase in cancer development, progression and therapeutic resistance; making it a viable therapeutic target. Here, we examined the impact of resveratrol-mediated pharmacological activation of SIRT1 on the progression of HGPIN lesions (using the Pten-/- mouse model) and on prostate tumor development (using an orthotopic model of prostate cancer cells stably silenced for SIRT1). We show that precise SIRT1 modulation could benefit both cancer prevention and treatment. Positive effect of SIRT1 activation can prevent Pten deletion-driven development of HGPIN lesions in mice if resveratrol is administered early (pre-cancer stage) with little to no benefit after the establishment of HGPIN lesions or tumor cell implantation. Mechanistically, our results show that under androgen deprivation conditions, SIRT1 inhibition induces senescence as evidenced by decreased gene signature associated with negative regulators of senescence and increased senescence-associated β-galactosidase activity. Furthermore, pharmacological inhibition of SIRT1 potentiated growth inhibitory effects of clinical androgen receptorblockade agents and radiation. Taken together, our findings provide an explanation for the discrepancy regarding the role of SIRT1 in prostate tumorigenesis. Our results reveal that the bifurcated roles for SIRT1 may occur in stage and context-dependent fashion by functioning in an antitumor role in prevention of early-stage prostate lesion development while promoting tumor development and disease progression post-lesion development. Clinically, these data highlight the importance of precise SIRT1 modulation to provide benefits for cancer prevention and treatment including sensitization to conventional therapeutic approaches.

IL-6 Signaling Link between Inflammatory Tumor Microenvironment and Prostatic Tumorigenesis

Benign prostatic hyperplasia and prostate cancer are tumoral pathologies characterized by the overexpression of inflammatory processes. The exploration of tumor microenvironment and understanding the sequential events that take place in the stromal area of the prostate could help for an early management of these pathologies. This way, it is feasible the hypothesis that normalizing the stromal environment would help to suppress or even to reverse tumor fenotype. A number of immunological and genetic factors, endocrine dysfunctions, metabolic disorders, infectious foci, nutritional deficiencies, and chemical irritants could be involved in prostate tumor development by maintaining inflammation, affecting local microcirculation, and promoting oxidative stress. Inflammatory processes activate hyperproliferative programs that ensure fibromuscular growth of the prostate and a number of extracellular changes. Acute and chronic inflammations cause accumulation of immunocompetent cells in affected prostate tissue (T cells, macrophages, mastocytes, dendritic cells, neutrophils, eosinophils, monocytes). Prostate epithelial and stromal cells, peri-prostatic fat cells, prostatic microvascular endothelial cells, and inflammatory cells produce cytokines, generating a local inflammatory environment. Interleukin-6 (IL-6) proved to be involved in the prostate tumor pathogenesis. IL-6 ability to induce pro- and anti-inflammatory responses by three mechanisms of signal transduction (classical signaling, transsignaling, cluster signaling), to interact with a diversity of target cells, to induce endocrine effects in an autocrine/paracrine manner, and the identification of an IL-6 endogenous antagonist that blocks the transmission of IL-6 mediated intracellular signals could justify current theories on the protective effects of this cytokine or by alleviating inflammatory reactions or by exacerbating tissue damage. This analysis presents recent data about the role of the inflammatory process as a determining factor in the development of benign and malign prostate tumors. The presented findings could bring improvements in the field of physiopathology, diagnosis, and treatment in patients with prostate tumors. Modulation of the expression and activity of interleukin-6 could be a mean of preventing or improving these pathologies.

A chemical probe for BAG1 targets androgen receptor-positive prostate cancer through oxidative stress signaling pathway

SummaryBAG1 is a family of polypeptides with a conserved C-terminal BAG domain that functions as a nucleotide exchange factor for the molecular chaperone HSP70. BAG1 proteins also control several signaling processes including proteostasis, apoptosis, and transcription. The largest isoform, BAG1L, controls the activity of the androgen receptor (AR) and is upregulated in prostate cancer. Here, we show that BAG1L regulates AR dynamics in the nucleus and its ablation attenuates AR target gene expression especially those involved in oxidative stress and metabolism. We show that a small molecule, A4B17, that targets the BAG domain downregulates AR target genes similar to a complete BAG1L knockout and upregulates the expression of oxidative stress-induced genes involved in cell death. Furthermore, A4B17 outperformed the clinically approved antagonist enzalutamide in inhibiting cell proliferation and prostate tumor development in a mouse xenograft model. BAG1 inhibitors therefore offer unique opportunities for antagonizing AR action and prostate cancer growth.

Molecular characterization of human papillomavirus and mouse mammary tumor virus-like infections in prostate cancer tissue and relevance with tumor characteristics.

The suspected roles of human Papillomavirus (HPV) and mouse mammary tumor virus (MMTV) infections in prostate tumor development were recently reported. To detect the frequency of HPV and MMTV-like infections and clinical correlates of tumor characteristics, DNA samples from 50 men treated at Teaching Hospital of Rabat City (Morocco) between June 2017 and February 2019, were genotyped and confirmed by Sanger sequencing. Eight infections of HPV18 and two infections of MMTV-like were detected, and 50% of patients were at a Gleason score of 6. A significant association between Gleason score and HPV or MMTV-like infection was noted (P=0.0008); 90% of patients with viral infections presented with T1 and T2 pathological stage tumors. Yet, no significant differences were found between infected and noninfected men regarding other pathological parameters including prostate-specific antigen (PSA), tumor histological stage, age at diagnosis and radical prostatectomy treatment (P=0.2179, 0.4702, 0.8101, and 0.9644, respectively). The molecular evolution of HPV and MMTV in comparison with previously aligned sequences was discussed. Our findings provide a highlight on the correlations between the clinical-pathological parameters of prostate tumors and HPV and MMTV infections. Prospective studies with a wide sample size are needed for more statistical clarification of the association between viral infections with prostate tumor criteria.

Androgen Receptor as an Emerging Feasible Biomarker for Breast Cancer.

Biomarkers can be used for diagnosis, prognosis, and prediction in targeted therapy. The estrogen receptor α (ERα) and human epidermal growth factor receptor 2 (HER2) are standard biomarkers used in breast cancer for guiding disease treatment. The androgen receptor (AR), a nuclear hormone receptor, contributes to the development and progression of prostate tumors and other cancers. With increasing evidence to support that AR plays an essential role in breast cancer, AR has been considered a useful biomarker in breast cancer, depending on the context of breast cancer sub-types. The existing survival analyses suggest that AR acts as a tumor suppressor in ER + ve breast cancers, serving as a favorable prognostic marker. However, AR functions as a tumor promoter in ER-ve breast cancers, including HER2 + ve and triple-negative (TNBC) breast cancers, serving as a poor prognostic factor. AR has also been shown to be predictive of the potential of response to adjuvant hormonal therapy in ER + ve breast cancers and to neoadjuvant chemotherapy in TNBC. However, conflicting results do exist due to intrinsic molecular differences between tumors and the scoring method for AR positivity. Applying AR expression status to guide treatment in different breast cancer sub-types has been suggested. In the future, AR will be a feasible biomarker for breast cancer. Clinical trials using AR antagonists in breast cancer are active. Targeting AR alone or other therapeutic agents provides alternatives to existing therapy for breast cancer. Therefore, AR expression will be necessary if AR-targeted treatment is to be used.