Inflammation, Microbiota, and Prostate Cancer

Role of Chemokines and Cytokines in Prostate Cancer Skeletal Metastasis

PURPOSE OF REVIEW

Once prostate cancer (PCa) bone metastases develop, the prognosis dramatically declines. The precise mechanisms regulating bone metastasis remain elusive. This review will explore recent findings related to cytokines and chemokines in the process of bone metastases.

RECENT FINDINGS

We discuss the role of cytokines in tumor growth, invasion, bone remodelling and angiogenesis and immune regulation in PCa skeletal metastases. Major advances in our understanding focus on immune evasion, immune checkpoint blockade, tumor-associated macrophages (TAMs), CAR-T cells, cytokine regulation of matrix metalloproteinases, cytokines including IL-10, IL-27, Interferon-γ, prostate transmembrane protein androgen induced 1 (Pmepa1), and regulation of RUNX2 transcription in supporting survival and growth of disseminated tumor cells (DTCs) and metastases development. The review highlights the complexity of cytokine actions in PCa bone metastases, suggesting potential therapeutic targets to disrupt interactions between cancer cells and their microenvironment.

Influence of microbiome in intraprostatic inflammation and prostate cancer

BACKGROUND

Chronic infection and inflammation have been linked to the development of prostate cancer. Dysbiosis of the oral and gut microbiomes and subsequent microbial translocation can lead to pathogenic prostate infections. Microbial-produced metabolites have also been associated with signaling pathways that promote prostate cancer development. A comprehensive discussion on the mechanisms of microbiome infection and the prostate microenvironment is essential to understand prostate carcinogenesis.

METHODS

Published studies were used from the National Center for Biotechnology Information (NCBI) database to conduct a narrative review. No restrictions were applied in the selection of articles.

RESULTS

Microbiome-derived short-chain fatty acids (SCFAs) have been found to upregulate multiple signaling pathways, including MAPK and PI3K, through IGF-1 signaling and M2 macrophage polarization. SCFAs can also upregulate Toll-like receptors, leading to chronic inflammation and the creation of a pro-prostate cancer environment. Dysbiosis of oral microbiota has been correlated with prostate infection and inflammation. Additionally, pathogenic microbiomes associated with urinary tract infections have shown a link to prostate cancer, with vesicoureteral reflux potentially contributing to prostate infection.

CONCLUSIONS

This review offers a comprehensive understanding of the impact of microbial infections linked to intraprostatic inflammation as a causative factor for prostate cancer. Further studies involving the manipulation of the microbiome and its produced metabolites may provide a more complete understanding of the microenvironmental mechanisms that promote prostate carcinogenesis.

Molecular Pathology of Prostate Cancer

Molecular profiling studies have shed new light on the complex biology of prostate cancer. Genomic studies have highlighted that structural rearrangements are among the most common recurrent alterations. In addition, both germline and somatic mutations in DNA repair genes are enriched in patients with advanced disease. Primary prostate cancer has long been known to be multifocal, but recent studies demonstrate that a large fraction of prostate cancer shows evidence of multiclonality, suggesting that genetically distinct, independently arising tumor clones coexist. Metastatic prostate cancer shows a high level of morphologic and molecular diversity, which is associated with resistance to systemic therapies. The resulting high level of intratumoral heterogeneity has important implications for diagnosis and poses major challenges for the implementation of molecular studies. Here we provide a concise review of the molecular pathology of prostate cancer, highlight clinically relevant alterations, and discuss opportunities for molecular testing.

Prognostic and therapeutic potential of senescent stromal fibroblasts in prostate cancer

The stromal component of the tumour microenvironment in primary and metastatic prostate cancer can influence and promote disease progression. Within the prostatic stroma, fibroblasts are one of the most prevalent cell types associated with precancerous and cancerous lesions; they have a vital role in the structural composition, organization and integrity of the extracellular matrix. Fibroblasts within the tumour microenvironment can undergo cellular senescence, which is a stable arrest of cell growth and a phenomenon that is emerging as a recognized hallmark of cancer. Supporting the idea that cellular senescence has a pro-tumorigenic role, a subset of senescent cells exhibits a senescence-associated secretory phenotype (SASP), which, along with increased inflammation, can promote prostate cancer cell growth and survival. These cellular characteristics make targeting senescent cells and/or modulating SASP attractive as a potential preventive or therapeutic option for prostate cancer.

Expression and clinical value of NLRP1 and NLRC4 inflammasomes in prostate cancer

The present study explored the clinical value of the protein expression levels of nucleotide binding oligomerization-like receptor family pyrin domain containing 1 (NLRP1) and nucleotide-binding oligomerization domain leucine-rich repeat and caspase recruitment domain-containing 4 (NLRC4) inflammasomes in the diagnosis and treatment of prostate cancer. A total of 54 patients with prostatic hyperplasia and 58 patients with prostate cancer were recruited at The First People's Hospital of Pinghu between January and May 2022. Immunohistochemical staining was used to determine the protein expression levels of the NLRP1 and NLRC4 inflammasomes in addition to the proinflammatory cytokines IL-18 and IL-1β in the two groups of patients. The protein expression levels of NLRP1 and NLRC4 inflammasome were significantly increased in patients with prostate cancer compared with patients with prostate hyperplasia. The differences in expression of NLRP1 and NLRC4 inflammatory vesicles in prostate cancer of different stages were also compared based on data from The Cancer Genome Atlas. The protein expression level of NLRP1 demonstrated a significant positive correlation with IL-1β and IL-18 expression, and the protein expression level of the NLRC4 inflammasome was significantly positively correlated with IL-18 expression. The protein expression levels of both NLRP1 and NLRC4 demonstrated a significant positive correlation with the Gleason score of prostate cancer. The expression of NLRP1 in tumor (T)3/T4 was significantly higher compared with T1 and expression of the NLRC4 inflammasome in T2 and T3/T4 was significantly higher compared with T1. Expression of the NLRP1 and NLRC4 inflammasomes was significantly higher in patients with prostate cancer, compared with patients with prostatic hyperplasia. Therefore, expression of NLRP1 and NLRC4 may promote tumorigenesis by promoting the maturation and release of proinflammatory cytokines IL-1β and IL-18. Expression of the NLRP1 and NLRC4 inflammasomes demonstrated a significant positive correlation with the risk of prostate cancer. Expression of the NLRP1 and NLRC4 inflammasomes in middle- and advanced-stage tumors was higher compared with early-stage tumors. These results suggested that inflammasome expression may serve a significant role in the progression of tumors and could provide a fixed value for the risk assessment and prognosis prediction of prostate cancer.

Prevalence of genotoxic bacteria in men undergoing biopsy for prostate cancer

BACKGROUND

New evidence suggests that bacteria-produced DNA toxins may have a role in the development or progression of prostate cancer. To determine the prevalence of these genes in a noninfection (i.e., colonized) state, we screened urine specimens in men before undergoing a biopsy for prostate cancer detection.

METHODS

We developed a multiplex polymerase chain reaction using three of the most described bacterial genotoxin gene primers: Colibactin (polyketone synthase [pks] gene island: clbN and clbB), cytotoxic necrotizing factor (cnf1) toxin, and cytolethal distending toxin B (cdtB) represented gene islands. After calibration on Escherichia coli samples of known genotypes, we used a training and validation cohort. We performed multiplex testing on a training cohort of previously collected urine from 45 men undergoing prostate biopsy. For the validation cohort, we utilized baseline urine samples from a previous randomized clinical trial (n = 263) with known prostate cancer outcomes.

RESULTS

The prevalence of four common bacterial genotoxin genes detected in the urine before prostate biopsy for prostate cancer is 8% (25/311). The prevalence of pks island (clbN and clbB), cnf1, and cdt toxin genes are 6.1%, 2.4%, and 1.7%, respectively. We found no association between urinary genotoxins and prostate cancer (p = 0.83). We did identify a higher proportion of low-grade cancer (92% vs. 44%) in those men positive for urinary genotoxin and higher-grade cancer in those genotoxin negative (8% vs. 56%, p = 0.001).

CONCLUSIONS

The prevalence of urinary genotoxins is low and does not correspond to a prostate cancer diagnosis. The urine was taken at one point in time and does not rule out the possibility of previous exposure.

Unlocking the Potential of the Human Microbiome for Identifying Disease Diagnostic Biomarkers

The human microbiome encodes more than three million genes, outnumbering human genes by more than 100 times, while microbial cells in the human microbiota outnumber human cells by 10 times. Thus, the human microbiota and related microbiome constitute a vast source for identifying disease biomarkers and therapeutic drug targets. Herein, we review the evidence backing the exploitation of the human microbiome for identifying diagnostic biomarkers for human disease. We describe the importance of the human microbiome in health and disease and detail the use of the human microbiome and microbiota metabolites as potential diagnostic biomarkers for multiple diseases, including cancer, as well as inflammatory, neurological, and metabolic diseases. Thus, the human microbiota has enormous potential to pave the road for a new era in biomarker research for diagnostic and therapeutic purposes. The scientific community needs to collaborate to overcome current challenges in microbiome research concerning the lack of standardization of research methods and the lack of understanding of causal relationships between microbiota and human disease.

Microbiomes of Urine and the Prostate Are Linked to Human Prostate Cancer Risk Groups

BACKGROUND

Bacteria play a suspected role in the development of several cancer types, and associations between the presence of particular bacteria and prostate cancer have been reported.

OBJECTIVE

To provide improved characterisation of the prostate and urine microbiome and to investigate the prognostic potential of the bacteria present.

DESIGN, SETTING, AND PARTICIPANTS

Microbiome profiles were interrogated in sample collections of patient urine (sediment microscopy: n = 318, 16S ribosomal amplicon sequencing: n = 46; and extracellular vesicle RNA-seq: n = 40) and cancer tissue (n = 204).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Microbiomes were assessed using anaerobic culture, population-level 16S analysis, RNA-seq, and whole genome DNA sequencing.

RESULTS AND LIMITATIONS

We demonstrate an association between the presence of bacteria in urine sediments and higher D'Amico risk prostate cancer (discovery, n = 215 patients, p < 0.001; validation, n = 103, p < 0.001, χ² test for trend). Characterisation of the bacterial community led to the (1) identification of four novel bacteria (Porphyromonas sp. nov., Varibaculum sp. nov., Peptoniphilus sp. nov., and Fenollaria sp. nov.) that were frequently found in patient urine, and (2) definition of a patient subgroup associated with metastasis development (p = 0.015, log-rank test). The presence of five specific anaerobic genera, which includes three of the novel isolates, was associated with cancer risk group, in urine sediment (p = 0.045, log-rank test), urine extracellular vesicles (p = 0.039), and cancer tissue (p = 0.035), with a meta-analysis hazard ratio for disease progression of 2.60 (95% confidence interval: 1.39-4.85; p = 0.003; Cox regression). A limitation is that functional links to cancer development are not yet established.

CONCLUSIONS

This study characterises prostate and urine microbiomes, and indicates that specific anaerobic bacteria genera have prognostic potential.

PATIENT SUMMARY

In this study, we investigated the presence of bacteria in patient urine and the prostate. We identified four novel bacteria and suggest a potential prognostic utility for the microbiome in prostate cancer.

Chronic Prostatitis: Impact of Lifestyle, Infection, and Inflammation on Semen Parameters

Chronic prostatitis is a widespread disease of the prostate affecting men’s sexual and reproductive health worldwide. Its leading causes are urogenital tract infections by microorganisms with a prostate tropism. This study aimed to evaluate semen parameters and the factors associated (lifestyle, urogenital infections, and inflammation) with the onset of chronic prostatitis symptoms. This case-control study included seventy-six donors: 30 volunteers with chronic prostatitis and 46 asymptomatic volunteers for urogenital infections as a control group. Sociodemographic, urinary symptoms, pain location, sexual and reproductive health and lifestyle-related variables were collected in a survey. Seminal quality, cytokine levels in semen and serum, and the presence of nineteen microorganisms in the urogenital tract were evaluated. Prostatitis was also associated with poor sperm morphology, more lipoperoxidation of the sperm membrane, and lower serum nitric oxide concentration. In addition, N. gonorrhoeae infection was detected more frequently in semen samples from volunteers with chronic prostatitis. Volunteers with chronic prostatitis report more frequently erectile dysfunction and premature ejaculation, anxiety, depression, and stress compared to the control group. Chronic prostate infections alter the microbiota from the genitourinary tract causing prostatitis, a disease that affects all life areas, including the familiar environment of patients. Chronic prostatitis affects seminal parameters, with a great impact on life quality and sexual and reproductive health. Despite being a relatively unexplored disease, much remains to be clarified regarding its diagnosis and treatment. Alterations in the genitourinary microbiota can favor sexually transmitted infections that produce chronic and systemic inflammation.

Inflammation induced by lipopolysaccharide advanced androgen receptor expression and epithelial-mesenchymal transition progress in prostatitis and prostate cancer

Background

To explore the mechanism of prostatic inflammation on prostate cancer (PCa) by comparing the changes of prostate epithelial cells and PCa cells in an inflammatory environment.

Methods

First, immunohistochemistry (IHC) was used to compare the level of expression of TNF-α, IL-1β, IL-6, and TGF-β between benign prostatic hyperplasia (BPH), prostatitis, and PCa. Then primary prostate epithelial cells were sampled from patients who were suspected of PCa and had histological prostatitis (HP) confirmed by pathological biopsy. Lipopolysaccharide (LPS) or BAY11-7082 were used to investigate the change of androgen receptor (AR) and AR-mediated transcription, epithelial-mesenchymal transition (EMT) in primary prostate epithelial cells, and lymph node carcinoma of the prostate (LNCap) cells.

Results

TNF-α, IL-1β, IL-6, and TGF-β were significantly increased in HP and PCa compared with those in BPH patients. The proliferation of primary prostate epithelial cells and LNCap cells got the inflection point at LPS 10 µg/mL. In an inflammatory environment with 10 µg/mL LPS, both primary prostate epithelial cell and LNCap cell viability increased, and AR, AR-mediated transcription, and EMT processes were significantly increased. Inhibitors of NF-κB with 10 nM BAY11-7082 decreased AR, AR-mediated transcription, and EMT processes.

Conclusions

NF-κB regulates AR expression and EMT in prostatitis and PCa, and NF-κB inhibitors may have potential therapeutic value.

IL-6 and IL-8 cytokines are associated with elevated prostate-specific antigen levels among patients with adenocarcinoma of the prostate at the Uganda Cancer Institute

Background:

The possible clinical application of specific cytokines and chemokines contributing to tumorigenesis and the clinical outcome of several cancers has been reported. However, less invasive and easily applicable biomarkers in prostate cancer diagnosis and prognostication are still lacking. This study assessed the levels of plasma cytokines in prostate cancer patients as potential biomarkers for noninvasive early diagnosis.

Methods:

The plasma levels of nine cytokines, IL-6, IL-8, IL-10, IL-1β, IL-17A, IL-2, M-CSF, IL-12 and IFN-α, were detected by Luminex^© liquid array-based multiplexed immunoassays in 56 prostate cancer patients on androgen deprivation therapy and radiotherapy and 27 normal healthy controls.

Results:

Levels of plasma proinflammatory cytokines IL-6 and IL-8 were markedly increased in prostate cancer patients compared with controls. There was, however, no significant difference in the concentrations of all cytokines in prostate cancer patients compared with controls. Increasing levels of IL-6 and IL-8 were significantly associated with high levels of plasma prostate-specific antigen (p < 0.05).

Conclusion:

Proinflammatory cytokines IL-6 and IL-8 are potential biomarkers for prostate cancer pathogenesis and could serve as markers of disease progression.

The differential presence of human polyomaviruses, JCPyV and BKPyV, in prostate cancer and benign prostate hypertrophy tissues

Background

Studies have shown that human polyomavirus infection may be associated with various human cancers. We investigated the potential relationship between the prevalence of JCPyVor BKPyV and prostate cancer (PC) in patients from Taiwan.

Methods

Patients with PC and benign prostate hypertrophy (BPH; 76 and 30 patients, respectively) were recruited for this study. Paraffin-embedded tissues and clinical information of the patients were obtained. The tissue sections were used for viral DNA detection and immunohistochemistry analysis was performed for examining viral large T (LT) and VP1 proteins. Regression analysis was used to evaluate the relationship between the clinical characteristics of the patients and the risk of JCPyV/BKPyV infection.

Results

The prevalence of JCPyV/BKPyV DNA was different in PC and BPH tissues (27/76 [35.52%] and 2/30 [6.7%], respectively, p = 0.003)]. The LT and VP1 proteins were detected in 27 (35.52%) and 29 PC (38.2%) specimens, respectively, but neither protein was detected in BPH samples (p < 0.001). PC cells were more susceptible to JCPyV infection than BPH tissues [odds ratio (OR) 7.71, 95% CI: 1.71–34.09, p = 0.003). Patients with PC showing high levels of prostate-specific antigen and high Gleason scores were associated with a high risk of viral infection (ORs 1.1, 95% CI 1.000–1.003; p = 0.045 and ORs 6.18, 95% CI 1.26–30.33, p = 0.025, respectively). The expression of LT protein associated with the risk of PC increased 2923.39-fold (95% CI 51.19–166,963.62, p < 0.001).

Conclusions

The findings indicate that JCPyV infection in PC cells may be associated with prostate cancer progression and prognosis.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08862-w.

The presence of chronic inflammation in positive prostate biopsy is associated with upgrading in radical prostatectomy

OBJECTIVE

This study aimed to determine the predictive effect of the presence of chronic prostatitis associated with prostate cancer (PCa) in prostate biopsy on Gleason score upgrade (GSU) in radical prostatectomy (RP) specimens.

MATERIALS AND METHODS

The data of 295 patients who underwent open or robotic RP with a diagnosis of localized PCa following biopsy were retrospectively analyzed. Patients were divided into two groups with and without GSU following RP. Predictive factors affecting GSU on biopsy were determined. The impact of chronic prostatitis associated with prostate cancer on GSU was examined via logistic regression analysis.

RESULTS

Out of 224 patients with Gleason 3+3 scores on biopsy, 145 (64.7%) had Gleason upgrade, and 79 (35.2%) had no upgrade. Whilst comparing the two groups with and without Gleason upgrade in terms of patient age, prostate-specific antigen (PSA) value, PSA density (PSAD), prostate volume (PV), neutrophil/lymphocyte (N/L) ratio, number of positive cores, percentage of positive cores, and Prostate Imaging Reporting and Data System version 2 score, no statistically significant difference was detected. The presence of chronic prostatitis associated with PCa was higher in the patient cohort with GSU in contrast to the other group (p < 0.001). According to the univariate logistic regression analysis, the presence of chronic prostatitis was identified to be an independent marker for GSU.

CONCLUSIONS

Pathologists and urologists should be careful regarding the possibility of a more aggressive tumor in the presence of chronic inflammation associated with PCa because inflammation within PCa was revealed to be linked with GSU after RP.

Immunologic disparities in prostate cancer between American men of African and European descent

Health disparities between American men of African and European descent (AA and EA, respectively) can be attributed to multiple factors, including disparities in socioeconomic status, access to healthcare, lifestyle, ancestry, and molecular aberrations. Numerous clinical trials and research studies are being performed to identify new and better therapeutic approaches to detect and treat prostate cancer. Of potential concern is the fact that the majority of the patients enrolled on these trials are EA. This disproportionate enrollment of EA could have implications when disease management recommendations are proposed without regard to the existing disparities in prostate cancer between races. With increasing advancements in immunotherapies, the immunological disparities between men of diverse ethnicities will need to be fully explored to develop novel and effective therapeutic approaches for prostate cancer patients globally. To help address this need, this review fully describes inequalities in prostate cancer at the immunological level between AA and EA.

Can leukocytospermia predict prostate cancer via its effects on mitochondrial DNA?

Leukocytospermia was previously reported to affect sperm quality by the production of reactive oxygen species (ROS) leading to oxidative stress (OS). In turn, OS decreases sperm functional integrity, increases sperm DNA damage and ultimately alters fertility status. To elucidate the impact of leukocytospermia on sperm nuclear DNA integrity and mitochondrial DNA (mtDNA) structure, we conducted a study including 67 samples from infertile patients with low level of leucocytes (Group 1: n = 20) and with leukocytospermia (Group 2: n = 47). In addition to standard sperm parameters' assessment, we measured the levels of inflammation biomarkers [interleukin-6 (IL-6) and interleukin-8 (IL-8)] and evaluated the oxidative status [malondialdehyde (MDA) and enzymatic and non-enzymatic antioxidants]. In addition, we evaluated the level of sperm nuclear DNA fragmentation and analysed mitochondrial DNA (mtDNA) of sperm cells by sequencing of 5 genes [cytochrome oxidase I (COXI), cytochrome oxidase II (COXII), cytochrome oxidase III (COXIII), adenosine triphosphate synthase 6 (ATPase 6) and adenosine triphosphate synthase 8 (ATPase 8)]. As expected, patients with leukocytospermia had significantly higher MDA levels (32.56 ± 24.30 nmole/ml) than patients without leukocytospermia (17.59 ± 9.60 nmole/ml) (p < .018). Also, sperm DNA fragmentation index (DFI) was significantly higher in Group 2 (33.05 ± 18.14%) as compared to Group 1 (14.19 ± 9.50%) (p < .001). The sequencing of mtDNA revealed a high number of substitutions in Group 2 (n = 102) compared to Group 1 (n = 5). These substitutions were observed mainly in COXI. Among COXI substitutions found in Group 2, twelve changes were previously described in patients with prostate cancer and six of them were shown associated with this pathology. These findings suggest that leukocytospermia may predispose to the manifestation of prostate cancer through modification of mitochondrial DNA and this may be promoted by OS.

Prostate Cancer Peripheral Blood NK Cells Show Enhanced CD9, CD49a, CXCR4, CXCL8, MMP-9 Production and Secrete Monocyte-Recruiting and Polarizing Factors

Natural killer (NK) cells, effector lymphocytes of the innate immunity, have been shown to be altered in several cancers, both at tissue and peripheral levels. We have shown that in Non-Small Cell Lung Cancer (NSCLC) and colon cancer, tumour associated circulating NK (TA-NK) and tumour infiltrating NK (TI-NK) exhibit pro-angiogenic phenotype/functions. However, there is still a lack of knowledge concerning the phenotype of peripheral blood (PB) NK (pNK) cells in prostate cancer (PCa). Here, we phenotypically and functionally characterized pNK from PCa patients (PCa TA-NKs) and investigated their interactions with endothelial cells and monocytes/macrophages. NK cell subset distribution in PB of PCa patients was investigated, by multicolor flow cytometry, for surface antigens expression. Protein arrays were performed to characterize the secretome on FACS-sorted pNK cells. Conditioned media (CM) from FACS-sorted PCa pTA-NKs were used to determine their ability to induce pro-inflammatory/pro-angiogenic phenotype/functions in endothelial cells, monocytes, and macrophages. CM from three different PCa (PC-3, DU-145, LNCaP) cell lines, were used to assess their effects on human NK cell polarization in vitro, by multicolor flow cytometry. We found that PCa pTA-NKs acquire the CD56brightCD9+CD49a+CXCR4+ phenotype, increased the expression of markers of exhaustion (PD-1, TIM-3) and are impaired in their degranulation capabilities. Similar effects were observed on healthy donor-derived pNK cells, exposed to conditioned media of three different PCa cell lines, together with increased production of pro-inflammatory chemokines/chemokine receptors CXCR4, CXCL8, CXCL12, reduced production of TNFα, IFNγ and Granzyme-B. PCa TA-NKs released factors able to support inflammatory angiogenesis in an in vitro model and increased the expression of CXCL8, ICAM-1, and VCAM-1 mRNA in endothelial cells. Secretome analysis revealed the ability of PCa TA-NKs to release pro-inflammatory cytokines/chemokines involved in monocyte recruitment and M2-like polarization. Finally, CMs from PCa pTA-NKs recruit THP-1 and peripheral blood CD14+ monocyte and polarize THP-1 and peripheral blood CD14+ monocyte-derived macrophage towards M2-like/TAM macrophages. Our results show that PCa pTA-NKs acquire properties related to the pro-inflammatory angiogenesis in endothelial cells, recruit monocytes and polarize macrophage to an M2-like type phenotype. Our data provides a rationale for a potential use of pNK profiling in PCa patients.

Role of tumor-associated immune cells in prostate cancer: angel or devil?

Prostate cancer is the most common malignancy in the reproductive system of older males. Androgen deprivation therapy (ADT) is an important treatment for prostate cancer patients. However, almost all prostate cancer patients unavoidably progress to the castration-resistant stage after ADT treatment. Recent studies have shown that tumor-associated immune cells play major roles in the initiation, progression, and metastasis of prostate cancer. Various phenotypes of tumor-associated immune cells have tumor-promoting or antitumor functions mediated by interacting with tumor cells. Here, we review the current knowledge of tumor-associated immune cells in prostate cancer.

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.

The microbiome in urological diseases

Due to the rapid development of next-generation sequencing, it has become possible to obtain information on the sequences of all genes in a specific microbiome. The detection of bacteria in patients with no urinary tract infections indicated that the dogma that “urine is sterile” was false, leading to active research regarding the roles of the urinary microbiome in the human urinary tract. Here, we present a review of the current literature regarding the role of the microbiome in urology.

The Urinary Microbiome and Anticancer Immunotherapy: The Potentially Hidden Role of Unculturable Microbes

Several urinary disorders, including overactive bladder, urinary incontinence, and interstitial cystitis, are often characterized by negative urine cultures. The application of metagenomics (i.e., 16S rRNA microbial profiling or whole-genome shotgun sequencing) to urine samples has enabled the identification of previously undetected bacteria, contributing to the discovery and characterization of the urinary microbiome. The most frequent species isolated are Lactobacillus (15%), Corynebacterium (14.2%), Streptococcus (11.9%), Actinomyces (6.9%), and Staphylococcus (6.9%). Although several studies are emerging in this context, the role of urinary microbiota in the pathogenesis of infections and in tumor carcinogenesis remains unclear. Furthermore, data on the activity of gut microbiota in modulating sensitivity to immune checkpoint inhibitors in advanced cancer patients suggest that the influence of urinary microbiota on tumor response to anticancer therapy should also be investigated. Moreover, its possible relationship with tumor mutational burden, which is in turn correlated with response to immunotherapy, should be the focus of future studies. Of note, the effect of antibiotics on this complex scenario seems to deserve careful consideration.

Increased Preoperative Plasma Level of Microbial 16S rDNA Translocation Is Associated With Relapse After Prostatectomy in Prostate Cancer Patients

Background: The environmental factors for promoting prostate cancer (PCa) recurrence remain unknown. Methods: A retrospective cross-sectional study was conducted in healthy men (n = 12) and PCa patients undergoing prostatectomy (n = 27). Plasma preoperative level of total cell-free bacterial 16S rDNA, a marker of microbial translocation, was evaluated by qPCR. Plasma levels of prostate-specific antigen (PSA) were evaluated by ELISA. Results: Similar degrees of microbial translocation were found in healthy men and patients. However, the levels of microbial 16S rDNA were increased in patients with cancer relapse (n = 10) compared to patients without relapse (n = 17) after prostatectomy. Furthermore, the levels of microbial 16S rDNA were marginally increased in patients with pT3 or pT4 tumors compared to those with pT 2 or less. The levels of microbial 16S rDNA tended to increase in patients with higher pathologic tumor stage, Gleason score, and margin and lymph node involvements; but these differences did not reach significance. Conclusion: The plasma 16S rDNA levels increased in patients with PCa who have biochemical recurrence and 16S rDNA levels were higher in patients with higher-grade PCa.

Genetic and molecular determinants of prostate cancer among Iranian patients: An update

Prostate cancer (PCa) is one of the most common age-related cancers among men. Various environmental and genetic factors are involved in the development and progression of PCa. In most cases, the primary symptoms of disease are not severe. Therefore, it is common for patients to be referred with severe clinical manifestations at advanced stages of disease. Since this malignancy is age related and Iran will face a significant increase in the number of seniors, it is expected that the prevalence of PCa among Iranian men will rise. PCa progression has been observed to be associated with genetic and ethnic factors. It may therefore be clinically useful to determine a panel of genetic markers, in addition to routine diagnostic methods, to detect tumors in the early stages. In the present review, we have summarized the reported genetic markers in PCa Iranian patients to pave the way for the determination of an ethnic specific genetic marker panel for the early detection of PCa. To understand the genetic and molecular biology of PCa among Iranians, we have categorized these genetic markers based on their cellular functions.

Is there a correlation between the aggressiveness of chronic asymptomatic prostatitis National Institutes of Health category IV and the Gleason score in patients with prostate cancer?

INTRODUCTION

We evaluated the correlation between the International Society of Urological Pathology (ISUP) grades and the aggressiveness grades of prostate inflammation in newly diagnosed prostate cancer patients with chronic asymptomatic prostatitis National Institiutes of Health (NIH) category IV (CAPNIHIV).

METHODS

The study comprised 357 consecutive patients with prostate cancer in whom a cancer diagnosis had been made via a prostate needle biopsy. Histological sections of the prostate biopsy specimens of the patients were reviewed and scored. Prostatic inflammation was scored using the aggressiveness grade of inflammation. The associations between the ISUP grades and the aggressiveness grades of inflammation were analyzed using logistic regression. The limitations of the study were its retrospective design and the limited number of cases.

RESULTS

In 110 (31%) patients, CAPNIHIV was detected: 56 (51%) patients had a grade 0 aggressiveness score, 34 (31%) patients had a grade 1 aggressiveness score, and 20 (18%) patients had a grade 2 aggressiveness score. The patients who had prostatic inflammation had 1.65 times (95% confidence interval [CI] 1.05-2.61) greater likelihood of a high ISUP grade (grade ≥3) compared with the patients who did not have prostatic inflammation. The association between the ISUP grade and the aggressiveness grade of inflammation was more pronounced for a grade 2 aggressiveness score (n= 20; odds ratio 2.97; 95% CI 1.14-7.71).

CONCLUSIONS

In prostate cancer patients with CAPNIHIV, there was a positive correlation between the inflammation aggressiveness grade and the ISUP grade. The aggressiveness of intraprostatic inflammation may be an important morphological factor affecting the Gleason score.

The seminal microbiome in health and disease

Owing to the fact that there are more microbial than human cells in our body and that humans contain more microbial than human genes, the microbiome has huge potential to influence human physiology, both in health and in disease. The use of next-generation sequencing technologies has helped to elucidate functional, quantitative and mechanistic aspects of the complex microorganism-host interactions that underlie human physiology and pathophysiology. The microbiome of semen is a field of increasing scientific interest, although this microbial niche is currently understudied compared with other areas of microbiome research. However, emerging evidence is beginning to indicate that the seminal microbiome has important implications for the reproductive health of men, the health of the couple and even the health of offspring, owing to transfer of microorganisms to the partner and offspring. As this field expands, further carefully designed and well-powered studies are required to unravel the true nature and role of the seminal microbiome.

Dietary inflammatory index is associated with increased risk for prostate cancer among Vietnamese men

OBJECTIVE

Inflammatory potential of diet, as measured by the dietary inflammatory index (DII), has consistently been associated with an increased risk for prostate cancer (PCa). However, data has largely been reported in populations with more proinflammatory dietary patterns, whereas there is high diversity in dietary pattern worldwide. The aim of this study was to assess the association between DII scores and the risk for PCa in Vietnam.

METHODS

A case-control study of 652 participants (244 incident PCa patients, 64-75 y of age, and 408 controls, frequency matched for age) was conducted in Ho Chi Minh City, Vietnam, from 2013 to 2015. Habitual diet was ascertained using a validated food frequency questionnaire (FFQ), whereas other factors, including demographic and lifestyle characteristics, were assessed via face-to-face interviews. The daily intake of pro- and anti-inflammatory nutrients for each participant was calculated from the FFQ and used to estimate individuals' energy-adjusted DII (E-DII) scores. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models.

RESULTS

Comparing the middle and highest versus lowest tertile of DII scores, there was an increased risk for overall PCa. The OR and associated 95% CI was 2.63 (1.61-4.37) and 3.35 (2.06-5.53), respectively (P_trend < 0.01). Similar results were found for low-moderate and high-grade PCa. The respective ORs (95% CI) were 3.34 (1.66-7.13) and 5.29 (2.69-11.18), P_trend < 0.001, and 2.51 (1.40-4.63) and 2.57 (1.43-4.73), P_trend 0.006.

CONCLUSION

A proinflammatory diet was associated with increased risk for PCa among Vietnamese men.

Lack of Association between IL-6 Polymorphisms and Haplotypes with Gastric Cancer

The process of combating neoplasms and mononuclear cells, and during H. pylori infection, several pro-inflammatory and anti-inflammatory cytokines are synthesized. In view of the involvement of the IL-6 law and the presence of H. pylori in the development of gastric diseases, the present study aimed to characterize the promoter-region polymorphism -597 (G/A) (rs1800797), -572 (C/G) (rs1800796), and -174 (G/C) (rs1800795) by PCR-RFLP in 375 gastric biopsy specimens from patients with peptic symptoms. A total of 375 samples were analyzed: 87 patients (without lesion without gastric tissue); 236 patients with gastritis and 52 patients with gastric cancer analyzed the PCR-RFLP techniques. All the results were normalized in relation to the presence of H. pylori. The frequencies of the three polymorphisms were compared in the Control vs Gastritis groups and a statistically significant test observed: -174 (G/C) (OR: 1.27; 95% CI: 0.84-1.93; P = 0.26), 572 (C/G) (OR: 1.42; 95% CI: 0.78-2.59; P = 0.25), and 597 (G/A) (OR: 0.98; 95% CI, 0.64-1.52; P = 0.94). Similar results were obtained when the gastric cancer group was compared to the control group: -174 (G/C) (OR: 1.27; 95% CI: 0.66-2.47; P = 0.47), -572 (C/G) (OR: 1.07; 95% CI: 0.43-2.68; P = 0.88), and -597 (G/A) (OR: 1.01; 95% CI, 0.5-0.9; P = 0.99). The haplotypes were and were not observed statistically significant differences. In conclusion, we found no correlations between any of the three polymorphisms in the IL-6 gene analyzed in this study and a higher risk of gastritis or gastric cancer.

The influence of prostatic Cutibacterium acnes infection on serum levels of IL6 and CXCL8 in prostate cancer patients

Background

Chronic prostatic inflammation, caused by Cutibacterium acnes (C. acnes), has been proposed to influence the risk of prostate cancer development. In vitro studies have demonstrated the capacity of C. acnes to induce secretion of Interleukin 6 (IL6) and C-X-C motif chemokine ligand 8 (CXCL8) by prostate epithelial cells. Both these inflammatory mediators have been implicated in prostate cancer pathophysiology. In this cohort study, we aimed to investigate the influence of prostatic C. acnes on serum levels of IL6 and CXCL8.

Methods

We recruited 99 prostate cancer patients who underwent radical prostatectomy at Örebro University Hospital. The cultivation of pre-operatively obtained prostate biopsies identified C. acnes in 60 of the 99 patients. Levels of IL6 and CXCL8 in pre-operative serum samples were analyzed using ELISA, and concentrations were compared between prostate cancer patients with and without prostatic C. acnes infection using standard statistical methods.

Results

No statistical differences were observed in serum levels of IL6 and CXCL8 between subjects with and without prostatic C. acnes infection.

Conclusions

Our results indicate that prostatic C. acnes infection may give rise to low-grade inflammation with little effect on systemic levels of IL6 and CXCL8.

Association between Human Papillomavirus and Non-cervical Genital Cancers in Brazil: A Systematic Review and Meta-Analysis

Background: Human papillomavirus (HPV) infection is associated with cervical cancer; however, it is controversial whether it is involved in non-cervical genital cancers. Objective: This study aimed to evaluate articles on the prevalence of HPV in penile cancer, vulvar cancer, colorectal cancer, prostate cancer and anal canal cancer in studies conducted in Brazil. Methods: The study was conducted in accordance with the Preferred Reporting of Systematic Reviews and Meta-Analysis Statement. Comprehensive searches for HPV and cancer for the years 2006 to 2016 were conducted in two databases (PubMed and Web of Knowledge) and Google Scholar system. We also tracked the references of all eligible articles to identify additional non-captured publications through online surveys. Results: Eighteen studies, with a combined sample size of 1,552 patients were analyzed. The overall prevalence of HPV was 43% (95% CI: 36–51%; p < 0.001). The pooled prevalence of HPV in penile cancer was 42% (95% CI: 32–55%; p < 0.001), in colorectal cancer it was 67% (95% CI: 64–70%; p < 0.001) and in vulvar cancer 43% (95% CI: 34–55%; p < 0.001). HPV 16 was the most prevalent in all sites evaluated, with prevalence estimated at 54% (95% CI: 44–66%; p < 0.001), followed by genotypes 33 (21%; 95% CI: 17–28; p < 0.001), 6 (15%; 95% CI: 8–26%; p < 0.001), 11 (13%; 95% CI: 5–32%; p < 0.001) and 18 (12%; 95% CI: 7–22%; p < 0.001), respectively. The pooled prevalence of single infection was 82% and infection by multiple genotypes of HPV was 22%. Conclusion: Our study demonstrated a high prevalence of HPV in non-cervical genital cancers in Brazil, with predominance of genotype 16, providing evidence for the need for preventive and control measures to avoid future harm to the population.

Potential ameliorative effects of epigallocatechin‑3‑gallate against testosterone-induced benign prostatic hyperplasia and fibrosis in rats

Green tea is among the most popular beverages in the world and is an important source of phytoestrogens. Epigallocatechin‑3‑gallate (EGCG) is the major polyphenol in green tea. The aim of this study was to investigate the anti-benign prostatic hyperplasia (BPH) activity and underling mechanisms of EGCG in testosterone-induced BPH rats and in BPH-1 cells. Prostatic levels of oxidative stress and inflammation makers, as well as angiogenesis related growth factors were measured. Additionally, the prostatic levels of sex hormonal mediators (androgen receptor (AR), estrogen receptor (ER)-α and ER-β), hypoxia-inducible factor (HIF)-1α, transforming growth factor-β1 (TGF-β1), type I TGF-β receptor (TGF-βRI), Smad3, phosphorylation-Smad3 (p-Smad3), epithelial-mesenchymal transition (EMT) markers (E-cadherin, collagen-I, fibronectin and α-SMA) and microRNA (miR)-133a/b were analyzed by immunohistochemistry assay, western blot and/or quantitative RT-PCR. It was observed that EGCG attenuated the prostatic oxidative stress and inflammatory microenvironment, ameliorated prostatic hyperplasia and collagen deposition, reduced the levels of angiogenesis related growth factors, inhibited the over-expression of AR, ER-α, HIF-1α, TGF-β1, TGF-βRI and p-Smad3, enhanced the expression of ER-β, increased the levels of miR-133a/b, as well as relieved prostatic EMT in rats. Both HIF-1α inhibitor and EGCG decreased the expression of HIF-1α and TGF-β1, as well as attenuated EMT in BPH-1 cells. It indicated that EGCG could attenuate testosterone-induced BPH and fibrosis.

Association between male accesory gland infections and prostate cancer in Turkish men: A case-control study

It is well known that chronic inflammation contributes to several forms of human cancer. Although several studies have investigated the association between prostatitis and prostate cancer, there is a lack of specifically designed study about male accessory gland infections (MAGI) and prostate cancer co-occurrence. We aimed to investigate this association with a case-control study in Turkish men. A total of 155 patients were enrolled to the study. After the pathological examination of the transrectal ultrasound-guided prostate biopsy specimens, patients were divided the two groups as control and prostate cancer and the presence of MAGI was determined. Of 155 patients, 145 met inclusion criteria. In the prostate cancer group, MAGI diagnose was determined in 18 of 31 patients (58.06%), while it was determined in 25 of 114 (21.93%) patients in the control group (p = .001). A significant correlation between MAGI and pathological Gleason score also revealed (p = .0001). We demonstrated that men with MAGI have increased risk for the development of prostate cancer. Moreover, in this population, most of the prostate cancers tend to be clinically significant or high grade.

Phage Therapy in Prostatitis: Recent Prospects

Prostatitis has various etiology including bacterial infection and dysregulated immunity; some of its forms remain a serious therapeutic challenge. Inflammation occurs in all forms of this disorder and is proposed to predispose to the development of prostate cancer (PC). There are reports that phage therapy is effective in chronic bacterial prostatitis. Recent findings suggest that phages not only eliminate bacteria, but also mediate immunomodulating (for example, anti-inflammatory) functions. The immunomodulating effects of phages could be beneficial in treating all forms of prostatitis and play some role in the prevention of the development of PC. As the etiological factors contributing to the majority of prostatitis cases remains largely unknown, and management options are often likewise limited, phage therapy merits further research as an attractive therapeutic option given its immunomodulating effects irrespective of the underlying causative factor(s).

Comparison of Chemical Profiles, Anti-Inflammatory Activity, and UPLC-Q-TOF/MS-Based Metabolomics in Endotoxic Fever Rats between Synthetic Borneol and Natural Borneol

Natural borneol (NB, called “Bingpian”) is an important traditional Chinese medicine to restore consciousness, remove heat and relieve pain, all of which are inflammation-related diseases. Recently, due to the limited source of NB, synthetic borneol (SB) is widely used as a substitute for NB in clinics. However, little is known about the effects of SB instead of NB. Herein, the aim of the present study was to compare NB and SB on chemical profiles by gas chromatography-mass spectrometer (GC-MS) analysis, anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) metabolomic approaches in endotoxic fever induced in rats. Results showed that, in total, 13 volatile components could be identified in NB and SB by GC-MS analysis, in which a significant difference between them still existed. The main constituents in SB were iso-borneol and borneol, while borneol contributes to 98.96% of the amount in NB. Additionally, both NB and SB exhibited remarkable anti-inflammatory effects to reduce the level of inflammatory factors including NO, TNF-α and IL-6 in LPS-induced RAW 264.7 macrophages, and lower the high body temperature in rats with endotoxic fever induced by LPS. Moreover, it seems that NB exhibited higher efficacy than SB. The unequal bioactive efficiency between NB and SB was also indicated by means of non-targeting metabolomics. Based on UPLC-Q-TOF/MS technology, 12 biomarkers in the serum of fever rats were identified. Pathway analysis revealed that the anti-fever effect of NB and SB was related to regulating the abnormal glycerophospholipid, linoleic acid and alpha-linoleic acid metabolism pathways in the fever model. Results indicated that there was still a great difference between NB and SB involving chemical constituents, anti-inflammation activity and the ability to regulate the abnormal metabolism pathways of the fever model. Certainly, further studies are warranted to better understand the replacement rationale in medicinal application.