Inflammation and prostate carcinogenesis

Comprehensive appraisal of the association between sexually transmitted infections and prostate cancer: A scoping review of empirical studies, reviews, and meta-analyses

We performed a scoping review on the association of sexually transmitted infections (STIs) with prostate cancer and identified knowledge gaps. Searching four databases (Medline, Embase, Scopus, and Cochrane) identified 286 eligible records. Most empirical studies (n = 191) were cross-sectional (n = 66) and case-control (n = 52). The most studied STIs were human papillomavirus (HPV) (n = 82), human immunodeficiency virus (HIV) (n = 52), and herpes simplex virus (HSV) (n = 30). We included 68 narrative reviews, 10 systematic reviews, and 17 meta-analyses. Most effect estimates (odds ratios, hazard ratios, risk ratios and standardised incidence ratios) did not support an association between STIs and prostate cancer: 373 and 218 of 591 effect estimates were above and below the null, respectively, except for HIV where 74 of 108 estimates were below the null. Knowledge gaps included case-control studies, insights into HIV-related mechanisms for a lower risk for prostate cancer, studies on Mycoplasma and Ureaplasma, studies adjusting for co-infection with other STIs, and studies assessing whether STIs predispose men to a more aggressive form of prostate cancer. A key research priority identified is the need for more evidence on the biological mechanisms driving infection-mediated prostate carcinogenesis.

Role of Furfural and 5-Methyl-2-furfural in Glucose-Induced Inhibition of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) Formation in Chemical Models and Pork Patties

The effects of furfural and 5-methyl-2-furfural produced by the Maillard reaction on PhIP formation were investigated in chemical models and roasted pork patties. In the chemical models, the results indicated that increasing levels of furfural (r = -0.7338, R2 = 0.9557) and 5-methyl-2-furfural (r = -0.7959, R2 = 0.9864) significantly reduced PhIP formation, displaying a strong linear correlation. The effects of furfural and 5-methyl-2-furfural on the precursors of phenylalanine (Phe) and phenylacetaldehyde showed a significant reduction in the Phe level, while the level of phenylacetaldehyde was not increased. In addition, neither furfural nor 5-methyl-2-furfural could significantly reduce creatinine or PhIP. Further mechanism studies showed that furfural (5-methyl-2-furfural) directly captured Phe to form the corresponding Schiff base compounds a (2-((furan-2-ylmethylene) amino)-3-phenylpropanoic acid) and b (2-(((5-methylfuran-2-yl)methylene)amino)-3-phenylpropanoic acid). This process reduced the production of phenylacetaldehyde, thereby inhibiting the PhIP formation pathway. More importantly, these two compounds were detected in roasted pork patties to which glucose was added. The above pathway was finally confirmed in roasted pork patties. These results revealed that furfural and 5-methyl-2-furfural, formed during the Maillard reaction, play a significant role in inhibiting the formation of PhIP by reacting with Phe.

Associations between inflammatory burden index, prostate cancer, and mortality among middle-aged and elderly individuals

BACKGROUND

Inflammation plays a crucial role in prostate cancer (PCa) progression and mortality. This study aimed to investigate the predictive value of the inflammatory burden index (IBI) and its components for mortality risk among men aged 40 years and older.

METHODS

A total of 7,344 participants from the NHANES 2001-2010 were included. High PCa risk was defined as a %fPSA greater than 25% and a tPSA level less than 4.0 ng/mL. Cox regression and logistic regression analyses were conducted to assess the association between IBI, PCa risk, and mortality. Receiver operating characteristic (ROC) curve analysis and random survival forest (RSF) model were utilized to evaluate the predictive value of IBI and its components for mortality.

RESULTS

Elevated IBI levels were significantly associated with an increased risk of all-cause mortality (HR = 1.08 [1.05-1.10]) and cancer mortality (HR = 1.11 [1.07-1.15]). High-risk PCa cases also exhibited elevated mortality risk (all-cause: HR = 1.35 [1.19-1.54]; cancer: HR = 1.65 [1.27-2.14]). Additionally, the combined effect of elevated IBI levels and high PCa risk showed a synergistic impact on mortality outcomes (all-cause: HR = 1.49 [1.27-1.74]; cancer: HR = 1.76 [1.29-2.40]). ROC curve analysis revealed that IBI had the highest AUC for predicting all-cause mortality (AUC = 0.690 at 3 years, 0.622 at 5 years, 0.634 at 10 years, and 0.632 at 15 years) compared to its individual components (CRP, NEU, LYM). RSF analysis highlighted IBI as the most significant predictor of all-cause and cancer mortality.

CONCLUSION

The combined effect of elevated IBI levels and high PCa risk demonstrated a synergistic impact on increased mortality risk among men aged 40 years and older. IBI demonstrated superior predictive performance for mortality outcomes compared to individual inflammatory markers. These findings underscore the potential utility of IBI as a prognostic biomarker for mortality risk assessment in individual with high PCa risk.

The current state of inflammation-related research in prostate cancer: a bibliometric analysis and systematic review

Background

Prostate cancer (PCa) is the second most prevalent malignancy among men globally. The diagnosis, treatment, and prognosis of prostate cancer frequently fall short of expectations. In recent years, the connection between inflammation and prostate cancer has attracted considerable attention. However, there is a lack of bibliometric studies analyzing the research on inflammation within the domain of prostate cancer.

Research methods

We utilized the Web of Science Core Collection (WOSCC) as our data source to extract articles and reviews related to inflammation in prostate cancer, published up until April 12, 2024. The collected data underwent meticulous manual screening, followed by bibliometric analysis and visualization using the Biblioshiny package in R.

Results

This study encompasses an analysis of 2,786 papers focusing on inflammation-related research within the realm of prostate cancer. Recent years have seen a significant proliferation of publications in this area, with the United States and China being the foremost contributors. The most prolific author in this domain is Demarzoam, with Johns Hopkins University standing out as the most influential institution. The leading journal in disseminating these studies is PROSTATE. Keyword co-occurrence analysis reveals that 'inflammation-related biomarkers', 'inflammation index', and 'tumor immune microenvironment' represent the current research hotspots and frontiers.

Conclusion

The findings of this bibliometric study serve to illuminate the current landscape of inflammation-related research in the field of prostate cancer, while further augmenting the discourse on inflammation-mediated cancer therapeutics. Of particular note is the potential of these discoveries to facilitate a more nuanced understanding among researchers regarding the interplay between inflammation and prostate cancer.

Cutibacterium acnes invades prostate epithelial cells to induce BRCAness as a possible pathogen of prostate cancer

BACKGROUND

Abundant evidence suggests that chronic inflammation is linked to prostate cancer and that infection is a possible cause of prostate cancer.

METHODS

To identify microbiota or pathogens associated with prostate cancer, we investigated the transcriptomes of 20 human prostate cancer tissues. We performed de novo assembly of nonhuman sequences from RNA-seq data.

RESULTS

We identified four bacteria as candidate microbiota in the prostate, including Moraxella osloensis, Uncultured chroococcidiopsis, Cutibacterium acnes, and Micrococcus luteus. Among these, C. acnes was detected in 19 of 20 prostate cancer tissue samples by immunohistochemistry. We then analyzed the gene expression profiles of prostate epithelial cells infected in vitro with C. acnes and found significant changes in homologous recombination (HR) and the Fanconi anemia pathway. Notably, electron microscopy demonstrated that C. acnes invaded prostate epithelial cells and localized in perinuclear vesicles, whereas analysis of γH2AX foci and HR assays demonstrated impaired HR repair. In particular, BRCA2 was significantly downregulated in C. acnes-infected cells.

CONCLUSIONS

These findings suggest that C. acnes infection in the prostate could lead to HR deficiency (BRCAness) which promotes DNA double-strand breaks, thereby increasing the risk of cancer development.

Spatial distribution of tumor-associated macrophages in an orthotopic prostate cancer mouse model

Mounting evidence suggests that the immune landscape within prostate tumors influences progression, metastasis, treatment response, and patient outcomes. In this study, we investigated the spatial density of innate immune cell populations within NOD.SCID orthotopic prostate cancer xenografts following microinjection of human DU145 prostate cancer cells. Our laboratory has previously developed nanoscale liposomes that attach to leukocytes via conjugated E-selectin (ES) and kill cancer cells via TNF-related apoptosis inducing ligand (TRAIL). Immunohistochemistry (IHC) staining was performed on tumor samples to identify and quantify leukocyte infiltration for different periods of tumor growth and E-selectin/TRAIL (EST) liposome treatments. We examined the spatial-temporal dynamics of three different immune cell types infiltrating tumors using QuPath image analysis software. IHC staining revealed that F4/80+ tumor-associated macrophages (TAMs) were the most abundant immune cells in all groups, irrespective of time or treatment. The density of TAMs decreased over the course of tumor growth and decreased in response to EST liposome treatments. Intratumoral versus marginal analysis showed a greater presence of TAMs in the marginal regions at 3 weeks of tumor growth which became more evenly distributed over time and in tumors treated with EST liposomes. TUNEL staining indicated that EST liposomes significantly increased cell apoptosis in treated tumors. Additionally, confocal microscopy identified liposome-coated TAMs in both the core and periphery of tumors, highlighting the ability of liposomes to infiltrate tumors by "piggybacking" on macrophages. The results of this study indicate that TAMs represent the majority of innate immune cells within NOD.SCID orthotopic prostate tumors, and spatial density varies widely as a function of tumor size, duration of tumor growth, and treatment of EST liposomes.

The Potential Preventive and Therapeutic Roles of NSAIDs in Prostate Cancer

Prostate cancer (PC) is the second most common type of cancer and the leading cause of death among men worldwide. Preventing the progression of cancer after treatments such as radical prostatectomy, radiation therapy, and hormone therapy is a major concern faced by prostate cancer patients. Inflammation, which can be caused by various factors such as infections, the microbiome, obesity and a high-fat diet, is considered to be the main cause of PC. Inflammatory cells are believed to play a crucial role in tumor progression. Therefore, nonsteroidal anti-inflammatory drugs along with their effects on the treatment of inflammation-related diseases, can prevent cancer and its progression by suppressing various inflammatory pathways. Recent evidence shows that nonsteroidal anti-inflammatory drugs are effective in the prevention and treatment of prostate cancer. In this review, we discuss the different pathways through which these drugs exert their potential preventive and therapeutic effects on prostate cancer.

Late puberty onset and lack of acne during adolescence reduce high-grade prostate cancer at adulthood

BACKGROUND

The interplay between pubertal events patterns (PEP) and prostate cancer (PCa) remains poorly understood. Therefore, we investigated the association of PEP with the odds of PCa, and PCa histological differentiation in men residents of Mexico city.

METHODS

In this case-control study, we analyzed the information of 371 incident prostate cancer cases and 775 controls matched on age (±5 years). High-grade prostate cancer was classified with Gleason score at diagnosis as ≥8. With information related to beard growth, age at maximum height attainment, and acne severity, the k-medoids algorithm was used to identify three mutually exclusive PEP (early, intermediate, and late). This association was evaluated using multivariable nonconditional logistic regression models.

RESULTS

Men with late PEP, characterized by age at maximum height attainment at around 23 years and no history of acne, was inversely associated with incident (odds ratio [OR]: 0.27; 95% confidence interval [CI]: 0.15-0.48, p trend <0.01) and high-grade prostate cancer (OR: 0.24; 95% CI: 0.09-0.59, p trend <0.01). Similar associations were observed even after adjusting by IGF-1 (OR: 0.19; 95% CI: 0.06-0.58) and androgens excretion (OR: 0.21; 95% CI: 0.06-0.66). Only the association between the absence of acne and prostate cancer remained significant after adjustment by these biomarkers.

CONCLUSIONS

This study suggests that pubertal characteristics might be helpful in identifying risk groups, among which, secondary prevention strategies could be applied. Also, the results agree with previous work suggesting other potential biological mechanisms involved in the etiology of prostate cancer such as the infectious and inflammatory pathways.

Interaction between drinking and dietary inflammatory index affects prostate specific antigen: a cross-sectional study

BACKGROUND

Numerous studies have shown that the dietary inflammatory index (DII) is associated with adverse health effects. However, the relationship between DII and prostate cancer (PCa) remains controversial. Although alcohol is included in DII as a dietary factor, the various adverse health effects of alcohol consumption are not only related to inflammation. On the other hand, it has been a long-standing debate whether alcohol consumption is linked to the risk of PCa. Therefore, to clarify whether drinking affects the relationship between DII and PCa, we evaluated the correlation between DII and prostate-specific antigen (PSA) based on the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

We used data from the NHANES spanning from 2005 to 2010 to analyze the relationship between PCa and DII. Out of the 31,034 NHANES participants, we enrolled 4,120 individuals in our study, utilizing dietary intake data from a twenty-four-hour period to determine DII scores. Demographic data, physical and laboratory test results were collected to compare between low PSA and high PSA groups, and to calculate the odds ratio between both groups, we employed a logistic regression analysis.

RESULTS

In this cross-sectional investigation of PCa, drinkers and non-drinkers had different relationships between DII and PSA levels (OR: 1.2, 95% Cl: 1-1.44 vs. OR: 0.98, 95% Cl: 0.9-1.07), and DII and abstaining from alcohol were effective in reducing the incidence of PSA (p-value for significant interaction = 0.037).

CONCLUSION

The results of our study suggest that drinking may influence the relationship between DII and PSA levels. DII is likely to be a reliable indicator for estimating PSA levels among non-drinkers, who may limit their intake of pro-inflammatory ingredients to lower the incidence and death of PCa.

Trinity of inflammation, innate immune cells and cross-talk of signalling pathways in tumour microenvironment

Unresolved inflammation is a pathological consequence of persistent inflammatory stimulus and perturbation in regulatory mechanisms. It increases the risk of tumour development and orchestrates all stages of tumorigenesis in selected organs. In certain cancers, inflammatory processes create the appropriate conditions for neoplastic transformation. While in other types, oncogenic changes pave the way for an inflammatory microenvironment that leads to tumour development. Of interest, hallmarks of tumour-promoting and cancer-associated inflammation are striking similar, sharing a complex network of stromal (fibroblasts and vascular cells) and inflammatory immune cells that collectively form the tumour microenvironment (TME). The cross-talks of signalling pathways initially developed to support homeostasis, change their role, and promote atypical proliferation, survival, angiogenesis, and subversion of adaptive immunity in TME. These transcriptional and regulatory pathways invariably contribute to cancer-promoting inflammation in chronic inflammatory disorders and foster "smouldering" inflammation in the microenvironment of various tumour types. Besides identifying common target sites of numerous cancer types, signalling programs and their cross-talks governing immune cells' plasticity and functional diversity can be used to develop new fate-mapping and lineage-tracing mechanisms. Here, we review the vital molecular mechanisms and pathways that establish the connection between inflammation and tumour development, progression, and metastasis. We also discussed the cross-talks between signalling pathways and devised strategies focusing on these interaction mechanisms to harness synthetic lethal drug combinations for targeted cancer therapy.

Predictive value of prostate calcification for future cancer occurrence: a retrospective long-term follow-up cohort study

OBJECTIVE

Although prostate calcification is often identified on pelvic CT images, calcification itself is usually not considered clinically significant. A recent histological study proposed an association between prostate calcification and prostate cancer occurrence. Our aim was to determine the predictive value of prostate calcifications for future prostate cancer occurrence.

METHODS

We retrospectively analysed male patients (≥50 years old) without prior prostate cancer history, who underwent unenhanced pelvic CT between April 2010 and March 2011, and followed-up until December 2021. Cox proportional hazards models were used to assess prostate cancer risk with prostate calcification (defined as a high-density area larger than 3 mm with CT attenuation values ≥ 130 HU), controlling for age, body mass index (BMI), hypertension and diabetes mellitus.

RESULTS

A total of 636 male patients (mean age, 68 years ± 9 [standard deviation]) were evaluated. At the end of follow-up, prostate cancer had been more frequently diagnosed in patients with prostate calcification than those without prostate calcification (6.5% vs  2.6%). Multivariate analysis revealed that prostate calcification on CT was a significant predictor of future prostate cancer occurrence (hazard ratio [HR], 2.7; 95% CI: 1.20, 5.91; p = 0.016). No statistical differences were observed in any other factors.

CONCLUSION

Prostate calcification may be a significant predictor of future prostate cancer occurrence, and may be used for risk stratification and to guide screening protocols.

ADVANCES IN KNOWLEDGE

Presence of prostate calcification on unenhanced CT scan was associated with increased incidence of prostate cancer occurrence on long term follow-up.

Potential role of gut microbiota in prostate cancer: immunity, metabolites, pathways of action?

The gut microbiota helps to reveal the relationship between diseases, but the role of gut microbiota in prostate cancer (PCa) is still unclear. Recent studies have found that the composition and abundance of specific gut microbiota are significantly different between PCa and non-PCa, and the gut microbiota may have common and unique characteristics between different diseases. Intestinal microorganisms are affected by various factors and interact with the host in a variety of ways. In the complex interaction model, the regulation of intestinal microbial metabolites and the host immune system is particularly important, and they play a key role in maintaining the ecological balance of intestinal microorganisms and metabolites. However, specific changes in the composition of intestinal microflora may promote intestinal mucosal immune imbalance, leading to the formation of tumors. Therefore, this review analyzes the immune regulation of intestinal flora and the production of metabolites, as well as their effects and mechanisms on tumors, and briefly summarizes that specific intestinal flora can play an indirect role in PCa through their metabolites, genes, immunity, and pharmacology, and directly participate in the occurrence, development, and treatment of tumors through bacterial and toxin translocation. We also discussed markers of high risk PCa for intestinal microbiota screening and the possibility of probiotic ingestion and fecal microbiota transplantation, in order to provide better treatment options for clinic patients. Finally, after summarizing a number of studies, we found that changes in immunity, metabolites.

Role of inflammatory factors in prediction of Gleason score and its upgrading in localized prostate cancer patients after radical prostatectomy

Purpose

To investigate the role of inflammatory factors including systemic immune-inflammation index (SII) and neutrophil to lymphocyte ratio (NLR) in predicting Gleason Score (GS) and Gleason Score upgrading (GSU) in localized prostate cancer (PCa) after radical prostatectomy (RP).

Methods

The data of 297 patients who underwent prostate biopsy and RP in our center from January 2014 to March 2020 were retrospectively analyzed. Preoperative clinical characteristics including age, values of tPSA, total prostate volume (TPV), f/t PSA ratio, body mass index (BMI), biopsy GS and inflammatory factors including SII, NLR, lymphocyte to monocyte (LMR), neutrophil ratio (NR), platelet to lymphocyte ratio (PLR), lymphocyte ratio (LR), mean platelet volume (MPV) and red cell distribution (RDW) as well as pathological T (pT) stage were collected and compared according to the grades of RP GS (GS ≤ 6 and GS≥7), respectively. ROC curve analysis was used to confirm the discriminative ability of inflammatory factors including SII, NLR and their combination with tPSA for predicting GS and GSU. By using univariate and multivariate logistic regression analysis, the association between significant inflammatory markers and grades of GS were evaluated.

Results

Patients enrolled were divided into low (GS ≤ 6) and high (GS≥7) groups by the grades of GS. The median values of clinical factors were 66.08 ± 6.04 years for age, 36.62 ± 23.15 mL for TPV, 26.16 ± 33.59 ng/mL for tPSA and 0.15 ± 0.25 for f/t PSA ratio, 22.34 ± 3.14 kg/m² for BMI, 15 (5.1%) were pT1, 116 (39.1%) were pT2 and 166 (55.9%) were pT3. According to the student's t test, patients in high GS group had a greater proportion of patients with pT3 (P<0.001), and higher NLR (P=0.04), SII (P=0.037) and tPSA (P=0.015) compared with low GS group, the distribution of age, TPV, f/t PSA ratio, BMI, LMR, NR, PLR, LR, MPV and RDW did not show any significantly statistical differences. The AUC for SII, NLR and tPSA was 0.732 (P=0.007), 0.649 (P=0.045) and 0.711 (P=0.015), with threshold values of 51l.08, 2.3 and 10.31ng/mL, respectively. According to the multivariable logistic regression models, NLR ≥ 2.3 (OR, 2.463; 95% CI, 0.679-10.469, P=0.042), SII ≥ 511.08 (OR, 3.519; 95% CI 0.891-12.488; P=0.003) and tPSA ≥ 10.31 ng/mL (OR, 4.146; 95% CI, 1.12-15.35; P=0.033) were all independent risk factors associated with higher GS. The AUC for combination of SII, NLR with tPSA was 0.758 (P=0.003) and 0.756 (P=0.003), respectively. GSU was observed in a total of 48 patients with GS ≤ 6 (55.17%). Then patients were divided into 2 groups (high and low) according to the threshold value of SII, NLR, tPSA, SII+tPSA and NLR+tPSA, respectively, when the GSU rates were compared with regard to these factors, GSU rate in high level group was significantly higher than that in low level group, P=0.001, 0.044, 0.017, <0.001 and <0.001, respectively.

Conclusion

High SII, NLR and tPSA were associated with higher GS and higher GSU rate. SII was likely to be a more favorable biomarker for it had the largest AUC area compared with tPSA and NLR; the combination of SII or NLR with tPSA had greater values for predicting GS and GSU compared with NLR, SII or tPSA alone, since the AUC area of combination was much higher. SII, NLR were all useful inflammatory biomarkers for predicting GS and detecting GSU among localized PCa patients with biopsy GS ≤ 6.

Microbiome and Prostate Cancer: A Novel Target for Prevention and Treatment

Growing evidence of the microbiome's role in human health and disease has emerged since the creation of the Human Microbiome Project. Recent studies suggest that alterations in microbiota composition (dysbiosis) may play an essential role in the occurrence, development, and prognosis of prostate cancer (PCa), which remains the second most frequent male malignancy worldwide. Current advances in biological technologies, such as high-throughput sequencing, transcriptomics, and metabolomics, have enabled research on the gut, urinary, and intra-prostate microbiome signature and the correlation with local and systemic inflammation, host immunity response, and PCa progression. Several microbial species and their metabolites facilitate PCa insurgence through genotoxin-mediated mutagenesis or by driving tumor-promoting inflammation and dysfunctional immunosurveillance. However, the impact of the microbiome on PCa development, progression, and response to treatment is complex and needs to be fully understood. This review addresses the current knowledge on the host-microbe interaction and the risk of PCa, providing novel insights into the intraprostatic, gut, and urinary microbiome mechanisms leading to PCa carcinogenesis and treatment response. In this paper, we provide a detailed overview of diet changes, gut microbiome, and emerging therapeutic approaches related to the microbiome and PCa. Further investigation on the prostate-related microbiome and large-scale clinical trials testing the efficacy of microbiota modulation approaches may improve patient outcomes while fulfilling the literature gap of microbial-immune-cancer-cell mechanistic interactions.

PD-L1 Up-Regulation in Prostate Cancer Cells by Porphyromonas gingivalis

Chronic inflammation is known to contribute to various human cancers. Porphyromonas gingivalis (P. gingivalis), is a gram-negative oral keystone pathogen that may cause severe periodontitis and expresses several virulence factors to affect the host immune system. Periodontitis is a chronic infectious disease that while progression, may cause loss of attachment and destruction of the tooth supporting tissues. Prostate cancer is one of the most common malignancies in men. Increasing evidence links periodontitis with prostate cancer, however the mechanisms explaining this relationship remain unclear. The aim of this study was to investigate the expression and signaling pathway of programmed death ligand 1 (PD-L1) in a prostate cancer cell line after infection with P. gingivalis and stimulation with P. gingivalis components to reveal the mechanism of tumor-induced immune evasion associated with bacterial infection in the tumor environment. Prostate cancer cells were infected with different concentrations of viable P. gingivalis and treated with different concentrations of heat-killed P. gingivalis and P. gingivalis cell components, including the total membrane fraction, inner membrane fraction, outer membrane fraction, cytosolic fraction and peptidoglycan (PGN). Chemical inhibitors were used to block different important molecules of signaling pathways to assess the participating signal transduction mechanisms. PD-L1 expression was detected by Western blot after 24 h of infection. PD-L1 was demonstrated to be upregulated in prostate cancer cells after infection with viable and with heat-killed P. gingivalis membrane fractions. Also isolated PGN induced PD-L1 up-regulation. The upregulation was mediated by the NOD1/NOD2 signaling pathway. No upregulation could be detected after treatment of the cells with P. gingivalis lipopolysaccharide (LPS). These results indicate, that chronic inflammatory disease can contribute to tumor immune evasion by modifying the tumor microenvironment. Thus, chronic infection possibly plays an essential role in the immune response and may promote the development and progression of prostate cancer.

Identification of Pyroptosis-Related Gene Signatures and Construction of the Risk Model to Predict BCR in Prostate Cancer

Prostate cancer is one of the most common malignant tumors in men. Pyroptosis is related to tumor immune infiltration and tumor microenvironment (TME) and has been confirmed to be related to the progression of a variety of tumors. However, the relationship between prostate cancer and pyroptosis, as well as TME and tumor immune infiltration, has not been discussed yet. We obtained and combined the RNA-seq data of prostate cancer from TCGA and GEO databases, analyzed the differential expression of pyroptosis-related genes (PRGs), and divided them into two groups according to the PRG expression level. The relationship between pyroptosis subtypes and the TME of prostate cancer was further verified, and the differential expression genes (DEGs) in the two subtypes were identified. The relationship between the DEGs and clinicopathology was explored and KEGG and GO enrichment analysis was conducted; it was found that most DEGs were enriched in immune-related pathways. Then, we randomly divided datasets into training and testing sets, performed the LASSO and multicox progression analysis, selected eight genes as prognostic signatures and used the eight genes, calculated the risk score, and then separated the entire cohort into high- and low-risk groups. The prognosis between two groups and the 1-, 3-, and 5-year ROC curves of biochemical relapse (BCR) were verified in training, testing, and the entire cohort, respectively. The TME, CSC index, mutation, and drug susceptibility were also discussed.

Identification of ISG15 and ZFP36 as novel hypoxia- and immune-related gene signatures contributing to a new perspective for the treatment of prostate cancer by bioinformatics and experimental verification

Background

Prostatic cancer (PCa) is one of the most common malignant tumors in men worldwide. Emerging evidence indicates significance of hypoxia and immunity in PCa invasion and metastasis. This study aimed to develop a hypoxia- and immune-related gene risk signature and explore the molecular mechanisms to formulate a better prognostic tool for PCa patients.

Methods

The hypoxia and immune scores of all PCa patients in The Cancer Genome Atlas (TCGA) dataset were calculated via the maximally selected rank statistics method and the ESTIMATE algorithm. From common genes identified overlapping hypoxia- and immune-related differentially expressed genes (DE-HRGs and DE-IRGs), a hypoxia- and immune-related gene risk signature was developed utilizing univariate and multivariate Cox regression analyses, and validated in the Memorial Sloan Kettering Cancer Centre (MSKCC) database. The immune cell infiltration level of PCa samples were evaluated with ssGSEA algorithm. Differential expression of prognostic genes was evidenced by immunohistochemistry and western blot (WB) in paired PCa samples. Expression levels of these genes and their variations under regular and hypoxic conditions were examined in cell lines. The functional effects of the prognostic gene on PCa cells were examined by wound healing and transwell assays.

Results

A hypoxia- and immune-related gene risk signature constructed by ISG15 and ZFP36 displays significant predictive potency, with higher risk score representing worse survival. A nomogram based on independent prognostic factors including the risk score and Gleason score exhibited excellent clinical value in the survival prediction of PCa. Infiltration levels of eosinophils, neutrophils, Tcm, Tem, TFH, Th1 cells, and Th17 cells were significantly lower in the high-risk group. Conversely, aDC, pDC, T helper cells, and Tregs were significantly higher. Additionally, the two prognostic genes were closely correlated with the tumor-infiltrating immune cell subset in PCa progression. RT-qPCR and WB presented higher and lower expression of ISG15 and ZFP36 in PCa cells, respectively. They were correspondingly increased and decreased in PCa cells under hypoxic conditions. Wound healing and transwell assays showed that over-expression of ISG15 promoted the migration and invasion of PCa cells.

Conclusion

Our study identified a novel hypoxia- and immune-related gene signature, contributing a new perspective to the treatment of PCa

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03398-4.

The Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine Hair Dosimeter, DNA Adductomics Discovery, and Associations with Prostate Cancer Pathology Biomarkers

Well-done cooked red meat consumption is linked to aggressive prostate cancer (PC) risk. Identifying mutation-inducing DNA adducts in the prostate genome can advance our understanding of chemicals in meat that may contribute to PC. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a heterocyclic aromatic amine (HAA) formed in cooked meat, is a potential human prostate carcinogen. PhIP was measured in the hair of PC patients undergoing prostatectomy, bladder cancer patients under treatment for cystoprostatectomy, and patients treated for benign prostatic hyperplasia (BPH). PhIP hair levels were above the quantification limit in 123 of 205 subjects. When dichotomizing prostate pathology biomarkers, the geometric mean PhIP hair levels were higher in patients with intermediate and elevated-risk prostate-specific antigen values than lower-risk values <4 ng/mL (p = 0.03). PhIP hair levels were also higher in patients with intermediate and high-risk Gleason scores ≥7 compared to lower-risk Gleason score 6 and BPH patients (p = 0.02). PC patients undergoing prostatectomy had higher PhIP hair levels than cystoprostatectomy or BPH patients (p = 0.02). PhIP-DNA adducts were detected in 9.4% of the patients assayed; however, DNA adducts of other carcinogenic HAAs, and benzo[a]pyrene formed in cooked meat, were not detected. Prostate specimens were also screened for 10 oxidative stress-associated lipid peroxidation (LPO) DNA adducts. Acrolein 1,N²-propano-2'-deoxyguanosine adducts were detected in 54.5% of the patients; other LPO adducts were infrequently detected. Acrolein adducts were not associated with prostate pathology biomarkers, although DNA adductomic profiles differed between PC patients with low and high-grade Gleason scores. Many DNA adducts are of unknown origin; however, dG adducts of formaldehyde and a series of purported 4-hydroxy-2-alkenals were detected at higher abundance in a subset of patients with elevated Gleason scores. The PhIP hair biomarker and DNA adductomics data support the paradigm of well-done cooked meat and oxidative stress in aggressive PC risk.

HERV-K and HERV-H Env Proteins Induce a Humoral Response in Prostate Cancer Patients

A higher expression of human endogenous retroviruses (HERVs) has been associated with several malignancies, including prostate cancer, implying a possible use as a diagnostic or prognostic cancer biomarker. For this reason, we examined the humoral response against different epitopes obtained from the envelope protein of HERV-K (HERV-K env-su_19–37, HERV-K env-su_109–126), HERV-H (HERV-H env-su_229–241, HERV-H env_387–399) and HERV-W (HERV-W env-su_93–108, HERV-W env-su_248–262) in the plasma of patients affected by prostate cancer (PCa), and compared to that of benign prostate hyperplasia (BPH) and a borderline group of patients with atypical small acinar proliferation (ASAP) and prostate intraepithelial neoplasia (PIN) and healthy controls. A significant antibody response was observed against HERV-K env-su_109–126 (p = 0.004) and HERV-H env-su_229–241 (p < 0.0001) in PCa patients compared to HCs, BPH and borderline cohorts, whilst no significance difference was found in the antibodies against HERV-W env-su_93–108 and HERV-W env-su_248–262 in patients with PCa. Our results provided further proof of the association between HERV-K and PCa and added new evidence about the possible involvement of HERV-H in PCa pathogenesis, highlighting their possibility of being used as biomarkers of the disease.

Metabolism and biomarkers of heterocyclic aromatic amines in humans

Heterocyclic aromatic amines (HAAs) form during the high-temperature cooking of meats, poultry, and fish. Some HAAs also arise during the combustion of tobacco. HAAs are multisite carcinogens in rodents, inducing cancer of the liver, gastrointestinal tract, pancreas, mammary, and prostate glands. HAAs undergo metabolic activation by N-hydroxylation of the exocyclic amine groups to produce the proposed reactive intermediate, the heteroaryl nitrenium ion, which is the critical metabolite implicated in DNA damage and genotoxicity. Humans efficiently convert HAAs to these reactive intermediates, resulting in HAA protein and DNA adduct formation. Some epidemiologic studies have reported an association between frequent consumption of well-done cooked meats and elevated cancer risk of the colorectum, pancreas, and prostate. However, other studies have reported no associations between cooked meat and these cancer sites. A significant limitation in epidemiology studies assessing the role of HAAs and cooked meat in cancer risk is their reliance on food frequency questionnaires (FFQ) to gauge HAA exposure. FFQs are problematic because of limitations in self-reported dietary history accuracy, and estimating HAA intake formed in cooked meats at the parts-per-billion level is challenging. There is a critical need to establish long-lived biomarkers of HAAs for implementation in molecular epidemiology studies designed to assess the role of HAAs in health risk. This review article highlights the mechanisms of HAA formation, mutagenesis and carcinogenesis, the metabolism of several prominent HAAs, and the impact of critical xenobiotic-metabolizing enzymes on biological effects. The analytical approaches that have successfully biomonitored HAAs and their biomarkers for molecular epidemiology studies are presented.

Human Prostate Epithelial Cells Activate the AIM2 Inflammasome upon Cellular Senescence: Role of POP3 Protein in Aging-Related Prostatic Inflammation

Increased levels of type I (T1) interferon (IFN)-inducible POP3 protein in myeloid cells inhibit activation of the AIM2 inflammasome and production of IL-1β and IL-18 proinflammatory cytokines. The AIM2 mRNA levels were significantly higher in benign prostate hyperplasia (BPH) than the normal prostate. Further, human normal prostate epithelial cells (PrECs), upon becoming senescent, activated an inflammasome. Because in aging related BPH senescent PrECs accumulate, we investigated the role of POP3 and AIM2 proteins in pre-senescent and senescent PrECs. Here we report that the basal levels of the POP3 mRNA and protein were lower in senescent (versus young or old) PrECs that exhibited activation of the T1 IFN response. Further, treatment of PrECs and a BPH cell line (BPH-1) that expresses the androgen receptor (AR) with the male sex hormone dihydrotestosterone (DHT) increased the basal levels of POP3 mRNA and protein, but not AIM2, and inhibited activation of the AIM2 inflammasome. Of interest, a stable knockdown of POP3 protein expression in the BPH-1 cell line increased cytosolic DNA-induced activation of AIM2 inflammasome. These observations suggest a potential role of POP3 protein in aging-related prostatic inflammation.

Blood-Derived Biomarkers of Diagnosis, Prognosis and Therapy Response in Prostate Cancer Patients

Prostate cancer is among the most frequent cancers in men worldwide. Despite the fact that multiple therapeutic alternatives are available for its treatment, it is often discovered in an advanced stage as a metastatic disease. Prostate cancer screening is based on physical examination of prostate size and prostate-specific antigen (PSA) level in the blood as well as biopsy in suspect cases. However, these markers often fail to correctly identify the presence of cancer, or their positivity might lead to overdiagnosis and consequent overtreatment of an otherwise silent non-progressing disease. Moreover, these markers have very limited if any predictive value regarding therapy response or individual risk for therapy-related toxicities. Therefore, novel, optimally liquid biopsy-based (blood-derived) markers or marker panels are needed, which have better prognostic and predictive value than the ones currently used in the everyday routine. In this review the role of circulating tumour cells, extracellular vesicles and their microRNA content, as well as cellular and soluble immunological and inflammation- related blood markers for prostate cancer diagnosis, prognosis and prediction of therapy response is discussed. A special emphasis is placed on markers predicting response to radiotherapy and radiotherapy-related late side effects.

Links between Inflammation and Postoperative Cancer Recurrence

Despite complete resection, cancer recurrence frequently occurs in clinical practice. This indicates that cancer cells had already metastasized from their organ of origin at the time of resection or had circulated throughout the body via the lymphatic and vascular systems. To obtain this potential for metastasis, cancer cells must undergo essential and intrinsic processes that are supported by the tumor microenvironment. Cancer-associated inflammation may be engaged in cancer development, progression, and metastasis. Despite numerous reports detailing the interplays between cancer and its microenvironment via the inflammatory network, the status of cancer-associated inflammation remains difficult to recognize in clinical settings. In the current paper, we reviewed clinical reports on the relevance between inflammation and cancer recurrence after surgical resection, focusing on inflammatory indicators and cancer recurrence predictors according to cancer type and clinical indicators.

Chronic Inflammation and Cancer: The Role of Endothelial Dysfunction and Vascular Inflammation

Long-lasting subclinical inflammation is associated with a wide range of human diseases, particularly at a middle and older age. Recent reports showed that there is a direct causal link between inflammation and cancer development, as several cancers were found to be associated with chronic inflammatory conditions. In patients with cancer, healthy endothelial cells regulate vascular homeostasis, and it is believed that they can limit tumor growth, invasiveness, and metastasis. Conversely, dysfunctional endothelial cells that have been exposed to the inflammatory tumor microenvironment can support cancer progression and metastasis. Dysfunctional endothelial cells can exert these effects via diverse mechanisms, including dysregulated adhesion, permeability, and activation of NF-κB and STAT3 signaling. In this review, we highlight the role of vascular inflammation in predisposition to cancer within the context of two common disease risk factors: obesity and smoking. In addition, we discuss the molecular triggers, pathophysiological mechanisms, and the biological consequences of vascular inflammation during cancer development and metastasis. Finally, we summarize the current therapies and pharmacological agents that target vascular inflammation and endothelial dysfunction.

Application of Anti-Inflammatory Agents in Prostate Cancer

Chronic inflammation is a major cause of human cancers. The environmental factors, such as microbiome, dietary components, and obesity, provoke chronic inflammation in the prostate, which promotes cancer development and progression. Crosstalk between immune cells and cancer cells enhances the secretion of intercellular signaling molecules, such as cytokines and chemokines, thereby orchestrating the generation of inflammatory microenvironment. Tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) play pivotal roles in inflammation-associated cancer by inhibiting effective anti-tumor immunity. Anti-inflammatory agents, such as aspirin, metformin, and statins, have potential application in chemoprevention of prostate cancer. Furthermore, pro-inflammatory immunity-targeted therapies may provide novel strategies to treat patients with cancer. Thus, anti-inflammatory agents are expected to suppress the “vicious cycle” created by immune and cancer cells and inhibit cancer progression. This review has explored the immune cells that facilitate prostate cancer development and progression, with particular focus on the application of anti-inflammatory agents for both chemoprevention and therapeutic approach in prostate cancer.

Recruitment of miR-8080 by luteolin inhibits androgen receptor splice variant 7 expression in castration-resistant prostate cancer

A need exists for seeking effective treatments for castration-resistant prostate cancer (CRPC) in response to its emergence following androgen deprivation therapy as a major clinical problem. In the present study, we investigated the chemopreventive and chemotherapeutic potential of luteolin, a flavonoid with antioxidative properties, on prostate cancer, including CRPC. Luteolin inhibited the progression of rat prostate carcinogenesis by induction of apoptosis in a transgenic rat for adenocarcinoma of prostate (TRAP) model. Luteolin decreased cell proliferation in a dose-dependent manner and induced apoptosis with the activation of caspases 3 and 7 in both rat (PCai1, established from a TRAP prostate tumor) and human (22Rv1) CRPC cells. Dietary luteolin also suppressed tumor growth via an increase in apoptosis and inhibition of angiogenesis in PCai1 and 22Rv1 xenografts implanted in castrated nude mice. We also focused on androgen receptor splice variant 7 (AR-V7), which contributes to cell proliferation and therapeutic resistance in CRPC. Luteolin dramatically suppressed AR-V7 protein expression in 22Rv1 cells in vitro and ex vivo. Microarray analysis identified MiR-8080, which contains a possible target sequence for AR-V7 3'-UTR, as a gene upregulated by luteolin. MiR-8080 transfection decreased the AR-V7 expression level and the induction of apoptosis in 22Rv1 cells. Furthermore, miR-8080 knockdown canceled luteolin decreasing AR-V7 and the cell growth of 22Rv1. MiR-8080 induced by luteolin intake enhanced the therapeutic effect of enzalutamide on 22Rv1 xenografts under castration conditions. These results indicate luteolin inhibits CRPC by AR-V7 suppression through miR-8080, highlighting luteolin and miR-8080 as promising therapeutic agents for this disease.

Inflammatory serum markers and risk and severity of prostate cancer: The PROCA-life study

Whether chronic inflammation mirrored by high levels of systemic inflammatory markers such as high sensitive-CRP (hs-CRP) and white blood cell count (WBC) are associated with prostate cancer development remains unclear. In the Prostate Cancer Study throughout Life (PROCA-life), a prospective population-based cohort study, 7,356 men were included. Prediagnostic WBC and hs-CRP were assessed from blood collected at study entry; 2,210 participants also had a second CRP measure during follow-up. During a mean 11.8 years follow-up, 509 men developed prostate cancer (mean age at diagnosis 71.7 years). Multivariable Cox proportional hazard regression models were used to study whether individual biomarkers (WBC, hs-CRP), a combined score based on analyte tertiles (score range 2-6), or change in CRP were associated with risk and severity of prostate cancer. We observed a positive dose-response relationship between hs-CRP and prostate cancer risk with a Hazard Ratio (HR) per mg/l of 1.3, 95% CI 1.00-1.07. Men with an increase in hs-CRP between two measurements (Δhs-CRP) of ≥1.00 mg/l had a 36% increased risk of prostate cancer (HR 1.36, 95% CI 1.02-1.82), compared to men with no change or decrease in hs-CRP. Men with a systemic inflammatory score of 5 or 6 had a 68% higher risk of being diagnosed with metastatic disease (HR 1.68, 95% CI, 1.04-2.73) compared to men with lower scores. Our study supports that hs-CRP including repeated measurements alone or in combination with WBC may be a useful inflammation-related biomarker for prostate cancer risk and prognosis.

Inflammatory Potential of Diet and the Risk of Prostate Cancer: A Casecontrol Study in the West of Iran

Background:

Prostate cancer is one of the most common cancer in worldwide and inflammatory reactions may be the major risk factors for it. Diet has a potential role in the running of inflammatory reactions. Dietary Inflammatory Index (DII) is a tool that can assess the inflammatory potential of a diet.

Objective:

Study of the effect of Dietary Inflammatory Index (DII) and body composition on the risk of prostate cancer was the aim of this research.

Methods:

We assessed the ability of Dietary Inflammatory Index (DII) to predict prostate cancer in a case-control study conducted in Kermanshah, Iran in 2016. The study included 50 cases with primary prostate cancer and 150 healthy controls. Anthropometric indices were measured by Bioelectric Impedance Analysis (BIA). The DII was computed based on the intake of 32 nutrients assessed using a 147-items food frequency questionnaire. The multivariate logistic regression was used to evaluate the odds ratio, with DII expressed as a dichotomous variable.

Results:

There were no statistically significant differences in body composition between case and control groups, but participants with DII > 0.80 had significant differences in BMI, LBM, SLM, MBF and TBW versus participant with DII ≤ 0.80. Also, men with higher DII scores were at increased risk of prostate cancer [OR: 1.77; 95% confidence interval 1.28-2.44] and categorical variable [OR DII>0.80 vs ≤ 0.80: 3.81; 95% confidence interval: 1.49-9.75].

Conclusion:

These findings suggest that a pro-inflammatory diet is a risk factor for prostate cancer and also can have the impact on body composition.

The human gastrointestinal microbiota and prostate cancer development and treatment

The human gastrointestinal microbiome contains commensal bacteria and other microbiota that have been gaining increasing attention in the context of cancer development and response to treatment. Microbiota play a role in the maintenance of host barrier surfaces that contribute to both local inflammation and other systemic metabolic functions. In the context of prostate cancer, the gastrointestinal microbiome may play a role through metabolism of estrogen, an increase of which has been linked to the induction of prostatic neoplasia. Specific microbiota such as Bacteroides, Streptococcus, Bacteroides massiliensis, Faecalibacterium prausnitzii, Eubacterium rectalie, and Mycoplasma genitalium have been associated with differing risks of prostate cancer development or extensiveness of prostate cancer disease. In this Review, we discuss gastrointestinal microbiota's effects on prostate cancer development, the ability of the microbiome to regulate chemotherapy for prostate cancer treatment, and the importance of using Next Generation Sequencing to further discern the microbiome's systemic influence on prostate cancer.

Key Role of Obesity in Genitourinary Tumors with Emphasis on Urothelial and Prostate Cancers

Background: In human populations, a certain amount of data correlate obesity/body mass index (BMI) with urothelial cancer (UC) and prostate cancer (PCa) occurrence, however this is not fully elucidated at all stages of disease. In an attempt to shed light on uncertain areas in such field, in the present review we illustrate the main molecular mechanisms linking obesity and cancer, focusing on the correlation between obesity and tumor risk, disease progression and response to chemo- and immunotherapy in patients with UC and the predictive/prognostic role of obesity in PCa patients treated with the currently available therapeutic approaches. Methods: We did a large-scale literature search on existing scientific websites focusing on keywords "obesity", "body mass index (BMI)", "urothelial cancer", "prostate cancer", "docetaxel", "cabazitaxel", "abiraterone acetate", "enzalutamide", and "radium223". Results: Many adipocytes-induced molecules support tumor proliferation through activation of various cellular pathways. The available evidence in the postoperative setting do the role of BMI in oncological outcomes prediction still not completely clear. Likewise, in metastatic UC patients controversial results link the role of obesity/BMI with clinical outcomes of tumor response to chemotherapy. Adipose stromal cells recruitment, induced by PCa cells, from white adipose tissue to the tumor sites inducing cell invasiveness was associated with poor survival. Conflicting data, although more oriented towards a better survival outcome, resulted in obese patients treated with docetaxel. In PCa cell-lines a certain cabazitaxel chemo resistance adipose stromal cells (ASC)-mediated was demonstrated. In metastatic castration-resistant PCa patients with high BMI (>25 kg/m2) receiving abiraterone acetate there were significant worse survival outcomes, while in enzalutamide patients BMI did not affect survival outcome. In radium 223 patients higher BMI significantly correlated with favorable overall survival. Conclusions: The main focus of this review was to understand the interplay between obesity/BMI and UC/PCa. Several pathogenic cellular pathways exploring the issue are discussed, opening the way to challenging tailored treatments on the basis of BMI. Improving the knowledge of molecular connections between obesity and UC and PCa could favor the development of new therapies likely reducing chemo- and immunotherapy drug resistance.

Main Inflammatory Cells and Potentials of Anti-Inflammatory Agents in Prostate Cancer

Prostate cancer is the most common type of cancer and the leading cause of cancer deaths among men in many countries. Preventing progression is a major concern for prostate cancer patients on active surveillance, patients with recurrence after radical therapies, and patients who acquired resistance to systemic therapies. Inflammation, which is induced by various factors such as infection, microbiome, obesity, and a high-fat diet, is the major etiology in the development of prostate cancer. Inflammatory cells play important roles in tumor progression. Various immune cells including tumor-associated neutrophils, tumor-infiltrating macrophages, myeloid-derived suppressor cells, and mast cells promote prostate cancer via various intercellular signaling. Further basic studies examining the relationship between the inflammatory process and prostate cancer progression are warranted. Interventions by medications and diets to control systemic and/or local inflammation might be effective therapies for prostate cancer progression. Epidemiological investigations and basic research using human immune cells or mouse models have revealed that non-steroidal anti-inflammatory drugs, metformin, statins, soy isoflavones, and other diets are potential interventions for preventing progression of prostate cancer by suppressing inflammation. It is essential to evaluate appropriate indications and doses of each drug and diet.

Current Knowledge of the Potential Links between Inflammation and Prostate Cancer

Inflammation is inherent in prostatic diseases and it is now accepted that it may facilitate cellular proliferation in both benign and malignant conditions. The strong relationship between prostatic inflammation and pathogenesis of benign prostatic hyperplasia (BPH) is supported by epidemiologic, histopathologic and molecular evidence. Contrariwise, the role of inflammation in prostate carcinogenesis is still controversial, although current data indicate that the inflammatory microenvironment can regulate prostate cancer (PCa) growth and progression. Knowledge of the complex molecular landscape associated with chronic inflammation in the context of PCa may lead to the introduction and optimization of novel targeted therapies. In this perspective, evaluation of the inflammatory component in prostate specimens could be included in routine pathology reports.

A Systematic Review and Meta-analysis of Associations between Clinical Prostatitis and Prostate Cancer: New Estimates Accounting for Detection Bias

BACKGROUND

Previous meta-analyses have estimated summary positive associations between clinical prostatitis and prostate cancer. However, none have accounted for detection bias, the possibility for increased prostate cancer screening and detection in men with clinical prostatitis, in their pooled estimates.

METHODS

We searched for studies that investigated the relation between clinical prostatitis and prostate cancer through November 2018. Random effects meta-analysis was used to calculate summary odds ratios (OR) among all studies and in strata defined by methods used to reduce detection bias.Results: Although an increased odds of prostate cancer was seen among men with a history of clinical prostatitis in all 38 eligible studies combined [OR, 2.05; 95% confidence interval (CI), 1.64-2.57], this estimate attenuated to null among studies that performed the most rigorous analyses to limit detection bias (OR, 1.16; 95% CI, 0.77-1.74).

CONCLUSIONS

Our findings indicate that previously reported positive associations between clinical prostatitis and prostate cancer are likely due to detection bias.

IMPACT

Studies using rigorous detection bias methods are warranted to replicate these findings, as well as to examine the possible relation between prostate inflammation and prostate cancer directly, rather than indirectly through the diagnosis of "prostatitis," which includes a large proportion of men without evidence of prostate inflammation.

The association between epididymo-orchitis and prostate cancer: A nationwide population-based cohort study

To determine whether epididymo-orchitis, a common infectious disease among men, is associated with subsequent prostate cancer (PCa) via a nationwide cohort study.This nationwide population-based study of patients treated from 2001 to 2013 included a total of 4991 patients with epididymo-orchitis as the study group and 19,922 matched patients without epididymo-orchitis as a control group. We tracked the patients in both groups for a 5-year period to identify any new cases of PCa. Cox proportional hazards regressions were performed to calculate the hazard ratio (HR) of PCa during this 5-year follow-up period.Of the 24,913 patients in the study, 235 (0.9%) were newly diagnosed with PCa during the 5-year follow-up period; 77 (1.5%) of those were from the epididymo-orchitis group and 158 (0.8%) were from the control group. Compared to the patients without epididymo-orchitis, the adjusted HR for PCa for the patients with epididymo-orchitis was 1.56 (95% confidence interval [CI]: 1.18-2.06) during the 5-year follow-up period. Ages of more than 70 years, higher incomes, hypertension, and hyperlipidemia were more strongly associated withPCa in the study group than in the control group.The results were associated with a 56% increased risk for PCa among patients with epididymo-orchitis. Epididymo-orchitis may play an etiological role in the development of PCa in Asian populations. Further studies are warranted, however, to investigate the relationship between epididymo-orchitis and PCa.

Metabolic Activation of the Cooked Meat Carcinogen 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine in Human Prostate

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), an heterocyclic aromatic amine (HAA) formed in cooked meat, is a rodent and possible human prostate carcinogen. Recently, we identified DNA adducts of PhIP in the genome of prostate cancer patients, but adducts of 2-amino-3, 8-dimethylmidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-9 H-pyrido[2,3-b]indole (AαC), other prominent HAAs formed in cooked meats, were not detected. We have investigated the bioactivation of HAAs by Phase I and II enzymes in the human prostate (LNCaP) cell line using cytotoxicity and DNA adducts as endpoints. PhIP, MeIQx, and 2-amino-3-methylimidazo[4,5-f]quinoline, another HAA found in cooked meats, were poorly bioactivated and not toxic. The synthetic genotoxic N-hydroxylated-HAAs were also assayed in LNCaP cells with Phase II enzyme inhibitors. Notably, 2-hydroxy-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (HONH-PhIP), but not other HONH-HAAs, induced cytotoxicity. Moreover, PhIP-DNA adduct formation was 20-fold greater than adducts formed with other HONH-HAAs. Pretreatment of LNCaP cells with mefenamic acid, a specific inhibitor of sulfotransferase (SULT1A1), decreased PhIP-DNA adducts by 25%, whereas (Z)-5-(2'-hydroxybenzylidene)-2-thioxothiazolidin-4-one and pentachlorophenol, inhibitors of SULTs and N-acetyltransferases (NATs), decreased the PhIP-DNA adduct levels by 75%. NATs in cytosolic fractions of LNCaP cells and human prostate catalyzed DNA binding of HONH-PhIP by up to 100-fold greater levels than for SULT and kinase activities. Recombinant NAT2 is catalytically superior to recombinant NAT1 in the bioactivation of HONH-PhIP; however, the extremely low levels of NAT2 activity in prostate suggest that NAT1 may be the major isoform involved in PhIP-DNA damage. Thus, the high susceptibility of LNCaP cells recapitulates the DNA-damaging effect of HONH-PhIP in rodent and human prostate.

Obesity, Inflammation, and Prostate Cancer

The prevalence of obesity is increasing in the world, and obesity-induced disease, insulin-resistance, cardiovascular disease, and malignancies are becoming a problem. Epidemiological studies have shown that obesity is associated with advanced prostate cancer and that obese men with prostate cancer have a poorer prognosis. Obesity induces systemic inflammation via several mechanisms. High-fat diet-induced prostate cancer progresses via adipose-secretory cytokines or chemokines. Inflammatory cells play important roles in tumor progression. A high-fat diet or obesity changes the local profile of immune cells, such as myeloid-derived suppressor cells and macrophages, in prostate cancer. Tumor-associated neutrophils, B cells, and complements may promote prostate cancer in the background of obesity. Interventions to control systemic and/or local inflammation and changes in lifestyle may also be viable therapies for prostate cancer.

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.

Diet-related inflammation and risk of prostate cancer in the California Men's Health Study

PURPOSE

The purpose of the study was to examine the relationship between proinflammatory diet and prostate cancer risk.

METHODS

Energy-adjusted Dietary Inflammatory Index (E-DII) scores were computed among 40,161 participants in the California Men's Health Study. Over 9.7 ± 3.8 years of follow-up, 2707 incident prostate cancer cases were diagnosed and categorized as low-, intermediate-, or high-risk, based on disease grade and stage. Accelerated failure-time models assessed time to diagnosis of prostate cancer. Cox proportional hazard models estimated hazard ratios (HR) and 95% confidence intervals (95% CI). Nonlinear effects of E-DII were modeled as third-order polynomials.

RESULTS

Time to prostate cancer diagnosis did not differ by E-DII quartile. The HR for high-risk prostate cancer increased in the third E-DII quartile (HRQ3 vs. Q1 = 1.36; 95% CI: 1.04-1.76), but not in the fourth (HRQ4 vs. Q1 = 0.99; 95% CI: 0.74-1.32, Ptrend = .74), suggesting a nonlinear dose-response. HR curves for prostate cancer increased exponentially above an E-DII threshold of ≈+3.0. HR curves for high-risk prostate cancer had a much steeper incline above an E-DII threshold of ≈+2.5. Curves were higher among Blacks and Whites relative to other races and among overweight or obese men. No relationship was observed between E-DII scores and intermediate- or low-risk disease.

CONCLUSIONS

Relationships between proinflammatory diet and prostate cancer risk may be nonlinear, with an increased risk above an E-DII threshold of ≈+2.5.

Dietary Carcinogens and DNA Adducts in Prostate Cancer

Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer and the second leading cause of cancer-related to death in men. The major risk factors for PC are age, family history, and African American ethnicity. Epidemiological studies have reported large geographical variations in PC incidence and mortality, and thus lifestyle and dietary factors influence PC risk. High fat diet, dairy products, alcohol and red meats, are considered as risk factors for PC. This book chapter provides a comprehensive, literature-based review on dietary factors and their molecular mechanisms of prostate carcinogenesis. A large portion of our knowledge is based on epidemiological studies where dietary factors such as cancer promoting agents, including high-fat, dairy products, alcohol, and cancer-initiating genotoxicants formed in cooked meats have been evaluated for PC risk. However, the precise mechanisms in the etiology of PC development remain uncertain. Additional animal and human cell-based studies are required to further our understandings of risk factors involved in PC etiology. Specific biomarkers of chemical exposures and DNA damage in the prostate can provide evidence of cancer-causing agents in the prostate. Collectively, these studies can improve public health research, nutritional education and chemoprevention strategies.

Ethnic differences in TGFβ-signaling pathway may contribute to prostate cancer health disparity

Epidemiological studies show that the incidence and mortality rates of prostate cancer (PCa) are significantly higher in African-American (AA) men when compared with Caucasian (CA) men in the United States. Transforming growth factor β (TGFβ) signaling pathway is linked to health disparities in AAs. Recent studies suggest a role of TGFβ3 in cancer metastases and its effect on the migratory and invasive behavior; however, its role in PCa in AA men has not been studied. We determined the circulating levels of TGFβ3 in AA and CA men diagnosed with PCa using ELISA. We analyzed serum samples from both AA and CA men diagnosed with and without PCa. We show that AA PCa patients had higher levels of TGFβ3 protein compared with AA controls and CA patients. In fact, TGFβ3 protein levels in serum were higher in AA men without PCa compared with the CA population, which may correlate with more aggressive disease seen in AA men. Studies on AA-derived PCa cell lines revealed that TGFβ3 protein levels were also higher in these cells compared with CA-derived PCa cell lines. Our studies also reveal that TGFβ does not inhibit cell proliferation in AA-derived PCa cell lines, but it does induce migration and invasion through activation of PI3K pathway. We suggest that increased TGFβ3 levels are responsible for development of aggressive PCa in AA patients as a consequence of development of resistance to inhibitory effects of TGFβ on cell proliferation and induction of invasive metastatic behavior.

Chronic obstructive pulmonary disease with short-acting inhaled pharmacotherapy increases the risk of prostate cancer: A two-stage database approach

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) are at a higher risk of many types of cancer. However, specific investigation of the risk of prostate cancer and the influence of COPD pharmacotherapy in patients with COPD is lacking. This study investigated the risk and influence of COPD pharmacotherapy on risk of prostate cancer in patients with COPD.

METHODS

This retrospective cohort study used data from Taiwan's Longitudinal Health Insurance Database 2005 (LHID2005). The study cohort comprised COPD patients who received treatment between 2004 and 2008, and who were identified from the LHID2005. The control cohort comprised patients without COPD and was matched to the study cohort by age and sex. Two-stage propensity score calibration with the National Health Interview Survey 2005 was performed to obtain the missing confounders of smoking, alcohol drinking, and body mass index in the LHID. The hazard ratio (HR) and adjusted HR were estimated. Moreover, the influence of inhaled medications and other related medication on the risk of prostate cancer was analyzed by Cox proportional hazard regression.

RESULTS

The COPD cohort comprised 12,774 patients, and the control cohort comprised 38,322 patients (1:3). The incidence of prostate cancer was 633 per 100,000 person-years in the COPD cohort and 361 per 100,000 person-years in the control cohort. The propensity score calibration-adjusted HR was 1.62 (95% CI, 1.40-1.87, p < 0.001) in the COPD cohort. Further analysis revealed that the adjusted HR for the risk of prostate cancer was 1.61 (95% CI, 1.19-2.16, p = 0.002) in patients with COPD who used short-acting muscarinic antagonists (SAMAs) and 1.89 (95% CI, 1.40-2.54, p < 0.001) in patients with COPD who used short-acting beta-agonists (SABAs). COPD patients had lower risk of prostate cancer when using statin (HR = 0.63, 95% CI, 0.45-0.89, p = 0.010) or aspirin (HR = 0.55, 95% CI, 0.35-0.85, p = 0.008).

CONCLUSION

Patients with COPD are at a higher risk of prostate cancer, particularly those using SAMAs or SABAs. This finding suggests that inflammation control may be an effective strategy for decreasing the risk of prostate cancer.

Increased inflammatory potential of diet is associated with increased odds of prostate cancer in Argentinian men

PURPOSE

Various aspects of diet, including specific food items and nutrients, have been shown to modulate inflammation and have been implicated in the etiology of prostate cancer (PrCA). No study examining the role of diet-associated inflammation in PrCA has been conducted in Latin America.

METHOD

We examined the association between the Dietary Inflammatory Index (DII®) and PrCA in a population-based case-control study in Córdoba, Argentina. A total of 153 incident cases of PrCA and 309 controls frequency matched on sex, age (± 5 years), and place of residence were recruited from 2008 to 2015. The DII was developed to determine the inflammatory potential of individuals' diets and was computed from a validated food frequency questionnaire using nutrient data from diet only. Multi-level logistic regression models were fit to evaluate the association between DII scores and PrCA, adjusting for age, body mass index, energy intake, and occupational exposure as first-level covariates and family history of prostate cancer as the second-level variable. Odds ratios were estimated in all subject and stratified by BMI (< 30 vs. ≥ 30 kg/m2).

RESULTS

Men in the most pro-inflammatory group (tertile 3) had 50% higher odds of having PrCA compared to men in the most anti-inflammatory group (tertile 1) (ORtertile3 vs. tertile1 1.50; 95% CI 1.24-1.80). The odds of prostate cancer were higher in obese men (n = 109, ORtertile3 vs. tertile1 1.81; 95% CI 1.45-2.27), while no association was found among non-obese men (n = 375, ORtertile3 vs. tertile1 0.93; 95% CI 0.25-3.51).

CONCLUSIONS

A pro-inflammatory diet, reflected by higher DII scores, was positively associated with PrCA occurrence. Based on these results and those from other studies, steps should be taken to promote a diet rich in anti-inflammatory foods, in order to reduce risk of PrCA and other chronic diseases. Future studies should explore this association in a prospective setting.

Association between Dietary Inflammatory Index and Prostate Cancer in Shiraz Province of Iran

Background: Dietary components like food items and nutrients have been implicated to play a role in modulating inflammation and the development of prostate cancer. Studies examining this association have not been extensively explored in Middle Eastern Countries. Material and Methods: We examined the association between the dietary inflammatory index (DIITM) and prostate cancer in the Shiraz province of Iran. A total of 60 incident cases and 60 controls attending the same hospital as the cases were recruited. The energy adjusted DII (E-DIITM) was computed based on dietary intake assessed using a validated food frequency questionnaire (FFQ). Logistic regression was used to estimate odds ratios. Results: Men with higher E-DII (>0.96) were at higher risk of prostate cancer (OR = 2.55; 95% CI =1.04–6.23) compared to men with E-DII ≤0.96. Conclusion: These data suggest a pro-inflammatory diet, as indicated by increasing DII score, may be a risk factor for prostate cancer in Iranian men.

Natriuretic Peptides: The Case of Prostate Cancer

Cardiac natriuretic peptides have long been known to act as main players in the homeostatic control of blood pressure, salt and water balance. However, in the last few decades, new properties have been ascribed to these hormones. A systematic review of English articles using MEDLINE Search terms included prostate cancer, inflammation, cardiac hormones, atrial natriuretic peptide, and brain natriuretic peptide. Most recent publications were selected. Natriuretic peptides are strongly connected to the immune system, whose two branches, innate and adaptive, are finely tuned and organized to kill invaders and repair injured tissues. These peptides control the immune response and act as anti-inflammatory and immune-modulatory agents. In addition, in cancers, natriuretic peptides have anti-proliferative effects by molecular mechanisms based on the inhibition/regulation of several pathways promoting cell proliferation and survival. Nowadays, it is accepted that chronic inflammation is a crucial player in prostate cancer development and progression. In this review, we summarize the current knowledge on the link between prostate cancer and inflammation and the potential use of natriuretic peptides as anti-inflammatory and anticancer agents.

Association Between a Dietary Inflammatory Index and Prostate Cancer Risk in Ontario, Canada

BACKGROUND

Evidence exists showing that various aspects of diet are implicated in the etiology of prostate cancer, although results across studies remain inconsistent.

METHODS

We examined the ability of the dietary inflammatory index (DII) to predict prostate cancer in a case-control study conducted in Kingston, Ontario, Canada, between 1997 and 1999. The study included 72 cases of incident primary prostate cancer patients and 302 controls of urology clinic patients who had prostate conditions other than prostate cancer. The DII was computed based on intake of 18 nutrients assessed using a 67-item food frequency questionnaire. Univariate and multivariate logistic regression models were used to estimate odds ratios (ORs).

RESULTS

Men with higher DII scores were at increased risk of prostate cancer using DII score fit both as a continuous [OR = 1.58, 95% confidence interval (CI) 1.05-2.38] and categorical variable [compared to men in the lowest DII quartile, men in the highest quartile were at elevated risk (OR = 3.50, 95% CI 1.25-9.80; ptrend = 0.02)]. There was no significant heterogeneity by weight status, but stronger association was observed in men with body mass index >25 kg/m2 versus <25 kg/m2.

CONCLUSION

These findings suggest that a proinflammatory diet, as indicated by increasing DII score, is a risk factor for prostate cancer.

Prostate-specific IL-6 transgene autonomously induce prostate neoplasm through amplifying inflammation in the prostate and peri-prostatic adipose tissue

Background

The causative role of the pro-inflammatory cytokine IL-6 in prostate cancer progression has been well established at molecular level. However, whether and how IL-6 may play a role in prostate cancer risk and development is not well defined. One limitation factor to acquiring this knowledge is the lack of appropriate animal models.

Methods

We generated a novel line of prostate-specific IL-6 transgenic mouse model. We compared the prostate pathology, tumorigenic signaling components, and prostate tumor microenvironment of the IL-6 transgenic mice with wild type littermates.

Results

With this model, we demonstrate that IL-6 induces prostate neoplasm autonomously. We further demonstrate that transgenic expression of IL-6 in the prostate activates oncogenic pathways, induces autocrine IL-6 secretion and steadily-state of STAT3 activation in the prostate tissue, upregulates paracrine insulin-like growth factor (IGF) signaling axis, reprograms prostate oncogenic gene expression, and more intriguingly, amplifies inflammation in the prostate and peri-prostatic adipose tissue.

Conclusions

The pro-inflammatory IL-6 is autonomous oncogene for the prostate. IL-6 induces prostate oncogenesis through amplifying local inflammation. We also presented a valuable animal model to study inflammation and prostate cancer development.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0386-7) contains supplementary material, which is available to authorized users.

Lower Urinary Tract Infection and Subsequent Risk of Prostate Cancer: A Nationwide Population-Based Cohort Study

Purpose

We investigated whether lower urinary tract infection (LUTI), including cystitis or urethritis, is associated with an increased risk of developing prostate cancer (PCa), in a nationwide population-based cohort study.

Methods

We identified 14,273 men newly diagnosed with LUTI (9347 with cystitis, and 4926 with urethritis) between 1998 and 2011, from the Taiwan Longitudinal Health Insurance Database 2000. Each patient was randomly frequency-matched with 4 men without LUTI, based on age and index year of diagnosis. Cox’s proportional hazard regression analysis was performed to estimate the effect of LUTI on the PCa risk.

Results

The risk of developing PCa was significantly higher in the cystitis cohort (adjusted HR = 1.46, 95% CI = 1.20–1.78) and in the urethritis cohort (adjusted HR = 1.72, 95% CI = 1.26–2.34) than in the group without LUTI. Further analyses indicated that patients with more than 5 medical visits for LUTI per year had a significantly greater risk of developing PCa.

Conclusion

We found that cystitis or urethritis may play an etiological role in the development of PCa in Taiwanese men, particularly in those with repeated medical visits for cystitis or urethritis. Further studies are warranted on the association between LUTI and PCa in other countries, particularly where the prevalence of PCa is high.

Biomonitoring DNA Adducts of Cooked Meat Carcinogens in Human Prostate by Nano Liquid Chromatography-High Resolution Tandem Mass Spectrometry: Identification of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine DNA Adduct

Epidemiologic studies have reported an association between frequent consumption of well-done cooked meats and prostate cancer risk. However, unambiguous physiochemical markers of DNA damage from carcinogens derived from cooked meats, such as DNA adducts, have not been identified in human samples to support this paradigm. We have developed a highly sensitive nano-LC-Orbitrap MS n method to measure DNA adducts of several carcinogens originating from well-done cooked meats, tobacco smoke, and environmental pollution, including 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-9H-pyrido[2,3-b]indole (AαC), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), benzo[a]pyrene (B[a]P), and 4-aminobiphenyl (4-ABP). The limit of quantification (LOQ) of the major deoxyguanosine (dG) adducts of these carcinogens ranged between 1.3 and 2.2 adducts per 10 9 nucleotides per 2.5 μg of DNA assayed. The DNA adduct of PhIP, N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP) was identified in 11 out of 35 patients, at levels ranging from 2 to 120 adducts per 10 9 nucleotides. The dG-C8 adducts of AαC and MeIQx, and the B[a]P adduct, 10-(deoxyguanosin-N 2 -yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (dG-N 2 -B[a]PDE) were not detected in any specimen, whereas N-(deoxyguanosin-8-yl)-4-ABP (dG-C8-4-ABP) was identified in one subject (30 adducts per 10 9 nucleotides). PhIP-DNA adducts also were recovered quantitatively from formalin fixed paraffin embedded (FFPE) tissues, signifying FFPE tissues can serve as biospecimens for carcinogen DNA adduct biomarker research. Our biomarker data provide support to the epidemiological observations implicating PhIP, one of the most mass-abundant heterocyclic aromatic amines formed in well-done cooked meats, as a DNA-damaging agent that may contribute to the etiology of prostate cancer.

Dietary inflammatory index and prostate cancer risk in a case-control study in Mexico

Recent evidence suggests that a pro-inflammatory diet could be associated with prostate cancer (PC) risk. To evaluate the association between dietary inflammatory index (DII) and PC risk as well as aggressiveness, we conducted a case-control study in Mexico City. Cases were 394 individuals with incident, histologically confirmed PC, who were matched by age (±5 years) with 794 population controls. Dietary information was obtained through a semi-quantitative FFQ with a 3-year frame of reference before diagnosis, for cases, or interview, for controls. On the basis of twenty-eight food parameters, we estimated the energy-adjusted DII (E-DII). According to the Gleason score at diagnosis, PC cases were categorised as high (≥8), moderate (=7) and low (≤6) PC risk. Independent, unconditional logistic regression models adjusted for potential confounders were used to estimate PC risk and PC aggressiveness. There were no significant associations between overall PC risk and E-DII (OR3rd v. 1st tertile 1·18; 95 % CI 0·85, 1·63; P=0·33) or among men with high-risk PC (Gleason≥8) (OR 1·46; 95 % CI 0·88, 2·42; P=0·14). These results do not support the hypothesis that a pro-inflammatory diet is related to PC risk and PC aggressiveness. However, further studies with larger sample sizes, with sufficient statistical power and of varying designs should be conducted to address this hypothesis.