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

From microbes to medicine: harnessing the gut microbiota to combat prostate cancer

The gut microbiome (GM) has been identified as a crucial factor in the development and progression of various diseases, including cancer. In the case of prostate cancer, commensal bacteria and other microbes are found to be associated with its development. Recent studies have demonstrated that the human GM, including Bacteroides, Streptococcus, Bacteroides massiliensis, Faecalibacterium prausnitzii, Eubacterium rectale, and Mycoplasma genitalium, are involved in prostate cancer development through both direct and indirect interactions. However, the pathogenic mechanisms of these interactions are yet to be fully understood. Moreover, the microbiota influences systemic hormone levels and contributes to prostate cancer pathogenesis. Currently, it has been shown that supplementation of prebiotics or probiotics can modify the composition of GM and prevent the onset of prostate cancer. The microbiota can also affect drug metabolism and toxicity, which may improve the response to cancer treatment. The composition of the microbiome is crucial for therapeutic efficacy and a potential target for modulating treatment response. However, their clinical application is still limited. Additionally, GM-based cancer therapies face limitations due to the complexity and diversity of microbial composition, and the lack of standardized protocols for manipulating gut microbiota, such as optimal probiotic selection, treatment duration, and administration timing, hindering widespread use. Therefore, this review provides a comprehensive exploration of the GM's involvement in prostate cancer pathogenesis. We delve into the underlying mechanisms and discuss their potential implications for both therapeutic and diagnostic approaches in managing prostate cancer. Through this analysis, we offer valuable insights into the pivotal role of the microbiome in prostate cancer and its promising application in future clinical settings.

Icaritin-curcumol activates CD8+ T cells through regulation of gut microbiota and the DNMT1/IGFBP2 axis to suppress the development of prostate cancer

BACKGROUND

Prostate cancer (PCa) incidence and mortality rates are rising. Our previous research has shown that the combination of icariin (ICA) and curcumol (CUR) induced autophagy and ferroptosis in PCa cells, and altered lipid metabolism. We aimed to further explore the effects of the combination of ICA and CUR on gut microbiota, metabolism, and immunity in PCa.

METHODS

A mouse subcutaneous RM-1 cell tumor model was established. 16 S rRNA sequencing was performed to detect changes in fecal gut microbiota. SCFAs in mouse feces, and the effect of ICA-CUR on T-cell immunity, IGFBP2, and DNMT1 were examined. Fecal microbiota transplantation (FMT) was conducted to explore the mechanism of ICA-CUR. Si-IGFBP2 and si/oe-DNMT1 were transfected into RM-1 and DU145 cells, and the cells were treated with ICA-CUR to investigate the mechanism of ICA-CUR on PCa development.

RESULTS

After treatment with ICA-CUR, there was a decrease in tumor volume and weight, accompanied by changes in gut microbiota. ICA-CUR affected SCFAs and DNMT1/IGFBP2/EGFR/STAT3/PD-L1 pathway. ICA-CUR increased the positive rates of CD3+CD8+IFN-γ, CD3+CD8+Ki67 cells, and the levels of IFN-γ and IFN-α in the serum. After FMT (with donors from the ICA-CUR group), tumor volume and weight were decreased. SCFAs promote tumor development and the expression of IGFBP2. In vitro, DNMT1/IGFBP2 promotes cell migration and proliferation. ICA-CUR inhibits the expression of DNMT1/IGFBP2.

CONCLUSIONS

ICA-CUR mediates the interaction between gut microbiota and the DNMT1/IGFBP2 axis to inhibit the progression of PCa by regulating immune response and metabolism, suggesting a potential therapeutic strategy for PCa.

Current Trends and Challenges of Microbiome Research in Prostate Cancer

PURPOSE OF REVIEW

The role of the gut microbiome in prostate cancer is an emerging area of research interest. However, no single causative organism has yet been identified. The goal of this paper is to examine the role of the microbiome in prostate cancer and summarize the challenges relating to methodology in specimen collection, sequencing technology, and interpretation of results.

RECENT FINDINGS

Significant heterogeneity still exists in methodology for stool sampling/storage, preservative options, DNA extraction, and sequencing database selection/in silico processing. Debate persists over primer choice in amplicon sequencing as well as optimal methods for data normalization. Statistical methods for longitudinal microbiome analysis continue to undergo refinement. While standardization of methodology may help yield more consistent results for organism identification in prostate cancer, this is a difficult task due to considerable procedural variation at each step in the process. Further reproducibility and methodology research is required.

Targeted Nanoparticle-Based Diagnostic and Treatment Options for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest cancers, presents significant challenges in diagnosis and treatment due to its aggressive, metastatic nature and lack of early detection methods. A key obstacle in PDAC treatment is the highly complex tumor environment characterized by dense stroma surrounding the tumor, which hinders effective drug delivery. Nanotechnology can offer innovative solutions to these challenges, particularly in creating novel drug delivery systems for existing anticancer drugs for PDAC, such as gemcitabine and paclitaxel. By using customization methods such as incorporating conjugated targeting ligands, tumor-penetrating peptides, and therapeutic nucleic acids, these nanoparticle-based systems enhance drug solubility, extend circulation time, improve tumor targeting, and control drug release, thereby minimizing side effects and toxicity in healthy tissues. Moreover, nanoparticles have also shown potential in precise diagnostic methods for PDAC. This literature review will delve into targeted mechanisms, pathways, and approaches in treating pancreatic cancer. Additional emphasis is placed on the study of nanoparticle-based delivery systems, with a brief mention of those in clinical trials. Overall, the overview illustrates the significant advances in nanomedicine, underscoring its role in transcending the constraints of conventional PDAC therapies and diagnostics.

The elusive male microbiome: revealing the link between the genital microbiota and fertility. Critical review and future perspectives

There is a growing focus on understanding the role of the male microbiome in fertility issues. Although research on the bacterial communities within the male reproductive system is in its initial phases, recent discoveries highlight notable variations in the microbiome's composition and abundance across distinct anatomical regions like the skin, foreskin, urethra, and coronary sulcus. To assess the relationship between male genitourinary microbiome and reproduction, we queried various databases, including MEDLINE (available via PubMed), SCOPUS, and Web of Science to obtain evidence-based data. The literature search was conducted using the following terms "gut/intestines microbiome," "genitourinary system microbiome," "microbiome and female/male infertility," "external genital tract microbiome," "internal genital tract microbiome," and "semen microbiome." Fifty-one relevant papers were analyzed, and eleven were strictly semen quality or male fertility related. The male microbiome, especially in the accessory glands like the prostate, seminal vesicles, and bulbourethral glands, has garnered significant interest because of its potential link to male fertility and reproduction. Studies have also found differences in bacterial diversity present in the testicular tissue of normozoospermic men compared to azoospermic suggesting a possible role of bacterial dysbiosis and reproduction. Correlation between the bacterial taxa in the genital microbiota of sexual partners has also been found, and sexual activity can influence the composition of the urogenital microbiota. Exploring the microbial world within the male reproductive system and its influence on fertility opens doors to developing ways to prevent, diagnose, and treat infertility. The present work emphasizes the importance of using consistent methods, conducting long-term studies, and deepening our understanding of how the reproductive tract microbiome works. This helps make research comparable, pinpoint potential interventions, and smoothly apply microbiome insights to real-world clinical practices.

Microbiome and Prostate Cancer: Emerging Diagnostic and Therapeutic Opportunities

This review systematically addresses the correlation between the microbiome and prostate cancer and explores its diagnostic and therapeutic implications. Recent research has indicated an association between the urinary and gut microbiome composition and prostate cancer incidence and progression. Specifically, the urinary microbiome is a potential non-invasive biomarker for early detection and risk evaluation, with altered microbial profiles in prostate cancer patients. This represents an advancement in non-invasive diagnostic approaches to prostate cancer. The role of the gut microbiome in the efficacy of various cancer therapies has recently gained attention. Gut microbiota variations can affect the metabolism and effectiveness of standard treatment modalities, including chemotherapy, immunotherapy, and hormone therapy. This review explores the potential of gut microbiome modification through dietary interventions, prebiotics, probiotics, and fecal microbiota transplantation for improving the treatment response and mitigating adverse effects. Moreover, this review discusses the potential of microbiome profiling for patient stratification and personalized treatment strategies. While the current research identifies the pivotal role of the microbiome in prostate cancer, it also highlights the necessity for further investigations to fully understand these complex interactions and their practical applications in improving patient outcomes in prostate cancer management.

Intratumoural microbiota: a new frontier in cancer development and therapy

Human microorganisms, including bacteria, fungi, and viruses, play key roles in several physiological and pathological processes. Some studies discovered that tumour tissues once considered sterile actually host a variety of microorganisms, which have been confirmed to be closely related to oncogenesis. The concept of intratumoural microbiota was subsequently proposed. Microbiota could colonise tumour tissues through mucosal destruction, adjacent tissue migration, and hematogenic invasion and affect the biological behaviour of tumours as an important part of the tumour microenvironment. Mechanistic studies have demonstrated that intratumoural microbiota potentially promote the initiation and progression of tumours by inducing genomic instability and mutations, affecting epigenetic modifications, promoting inflammation response, avoiding immune destruction, regulating metabolism, and activating invasion and metastasis. Since more comprehensive and profound insights about intratumoral microbiota are continuously emerging, new methods for the early diagnosis and prognostic assessment of cancer patients have been under examination. In addition, interventions based on intratumoural microbiota show great potential to open a new chapter in antitumour therapy, especially immunotherapy, although there are some inevitable challenges. Here, we aim to provide an extensive review of the concept, development history, potential sources, heterogeneity, and carcinogenic mechanisms of intratumoural microorganisms, explore the potential role of microorganisms in tumour prognosis, and discuss current antitumour treatment regimens that target intratumoural microorganisms and the research prospects and limitations in this field.

The Association between Dietary Inflammatory Potential and Urologic Cancers: A Meta-analysis

A meta-analysis published in 2018 indicated a significant association between the dietary inflammatory index (DII) and risk of urologic cancers (UC). The number of included studies was limited, and more research has been published on this topic since then. The current study aimed to find a more precise estimate of the association between dietary inflammatory potential and risk of UC by updating the previous meta-analysis. The PubMed and Embase databases were searched between January 2015 and April 2023 to identify eligible articles. Combined relative risk (RR) and 95% confidence intervals (CI) were calculated by random-effects model to assess the association between dietary inflammatory potential and risk of UC by comparison of the highest versus the lowest category of the DII/empirical dietary inflammatory pattern (EDIP) or by using the continuous DII/EDIP score. The analysis, including 23 studies with 557,576 subjects, showed different results for UC. There was a significant association for prostate cancer among case-control studies (RR = 1.75, 95% CI: 1.34-2.28), whereas among cohort studies a null association was found (RR = 1.02, 95% CI: 0.96-1.08). For bladder cancer, a nonsignificant association was observed in both case-control (RR = 1.59, 95% CI: 0.95-2.64) and cohort studies (RR = 1.03, 95% CI: 0.86-1.24). Pooled RR from 3 case-control studies displayed a statistically significant association between the DII and risk of kidney cancer (RR = 1.27, 95% CI: 1.03-1.56). Although DII was positively associated with all types of UC, no association was found for EDIP. The present meta-analysis confirmed that an inflammatory diet has a direct effect on the development of prostate cancer and kidney cancer. Large-scale studies are needed to demonstrate the association between dietary inflammatory potential and risk of UC and provide effective nutritional advice for UC prevention. PROTOCOL REGISTRATION: The protocol was registered in the International Prospective Register of Systematic Reviews (CRD42023391204).

Microbiota and the landscape of the prostate tumor microenvironment

Prostate cancer remains one of the most common causes of cancer-related death in men globally. Progression of prostate cancer to lethal metastatic disease is mediated by multiple contributors. The role of prostate microbiota and their metabolites in metastasis, therapeutic resistance to castration resistant prostate cancer (CRPC), and tumor relapse has yet to be fully investigated. Characterization of microflora can provide new mechanistic insights into the functional significance in the emergence of therapeutic resistance, identification of novel effective targeted therapies, and development of biomarkers during prostate cancer progression. The tumor microenvironment (TME) and its components work concurrently with the prostate microbiota in promoting prostate cancer development and progression to metastasis. In this article, we discuss the growing evidence on the functional contribution of microbiota to the phenotypic landscape of the TME and its effect on prostate cancer therapeutic targeting and recurrent disease.

Causal associations between gut microbiota and urological tumors: a two-sample mendelian randomization study

BACKGROUND

Dysbiosis of gut microbiota has been linked to numerous diseases, including cancer. The unique role of gut microbiota in urological tumors is gaining prominence. However, it is still controversial whether the dysbiosis of gut microbiota should be one of the etiological factors of bladder cancer (BCa), prostate cancer (PCa) or kidney cancer (KCa).

MATERIALS AND METHODS

The microbiome genome-wide association study (GWAS) from the MiBioGen consortium (18,340 samples of 24 population-based cohorts) was utilized as the exposure data. Additionally, outcomes data (951 BCa cases and 307,092 controls; 1,631 KCa cases and 238,678 controls; 79,148 PCa cases and 61,106 controls) were extracted from the GWAS of the FinnGen and PRACTICAL consortia. To detect the potential causative bacterial traits for BCa, PCa, and KCa, a two-sample Mendelian randomization (MR) analysis was performed, employing the inverse-variance weighted or Wald ratio method. Sensitivity analyses were subsequently conducted to explore the robustness of the primary results. Finally, the reverse MR analysis was undertaken to mitigate the reverse causation.

RESULTS

This study suggested that Bifidobacterium (p = 0.030), Actinobacteria (p = 0.037 for phylum, 0.041 for class), and Ruminococcustorques group (p = 0.018), exhibited an association with an increased risk of BCa using either the inverse-variance weighted or Wald ratio method. By utilizing the Wald ratio method, Allisonella (p = 0.004, p = 0.038) was associated with a decreased risk of BCa and PCa, respectively. Furthermore, Ruminococcustorques group (p = 0.028) and Erysipelatoclostridium (p = 0.048) were causally linked to an elevated risk of KCa.

CONCLUSIONS

This MR study supports that genetically predicted gut microbiota is causally related to BCa, PCa and KCa. Additionally, distinct bacterial traits are identified in relation to each tumor type.

New insights into molecular signaling pathways and current advancements in prostate cancer diagnostics & therapeutics

Prostate adenocarcinoma accounts for more than 20% of deaths among males due to cancer. It is the fifth-leading cancer diagnosed in males across the globe. The mortality rate is quite high due to prostate cancer. Despite the fact that advancements in diagnostics and therapeutics have been made, there is a lack of effective drugs. Metabolic pathways are altered due to the triggering of androgen receptor (AR) signaling pathways, and elevated levels of dihydrotestosterone are produced due to defects in AR signaling that accelerate the growth of prostate cancer cells. Further, PI3K/AKT/mTOR pathways interact with AR signaling pathway and act as precursors to promote prostate cancer. Prostate cancer therapy has been classified into luminal A, luminal B, and basal subtypes. Therapeutic drugs inhibiting dihydrotestosterone and PI3K have shown to give promising results to combat prostate cancer. Many second-generation Androgen receptor signaling antagonists are given either as single agent or with the combination of other drugs. In order to develop a cure for metastasized prostate cancer cells, Androgen deprivation therapy (ADT) is applied by using surgical or chemical methods. In many cases, Prostatectomy or local radiotherapy are used to control metastasized prostate cancer. However, it has been observed that after 1.5 years to 2 years of Prostatectomy or castration, there is reoccurrence of prostate cancer and high incidence of castration resistant prostate cancer is seen in population undergone ADT. It has been observed that Androgen derivation therapy combined with drugs like abiraterone acetate or docetaxel improve overall survival rate in metastatic hormone sensitive prostate cancer (mHSPC) patients. Scientific investigations have revealed that drugs inhibiting poly ADP Ribose polymerase (PARP) are showing promising results in clinical trials in the prostate cancer population with mCRPC and DNA repair abnormalities. Recently, RISUG adv (reversible inhibition of sperm under guidance) has shown significant results against prostate cancer cell lines and MTT assay has validated substantial effects of this drug against PC3 cell lines. Current review paper highlights the advancements in prostate cancer therapeutics and new drug molecules against prostate cancer. It will provide detailed insights on the signaling pathways which need to be targeted to combat metastasized prostate cancer and castration resistant prostate cancer.

Dissecting Microbiome-Derived SCFAs in Prostate Cancer: Analyzing Gut Microbiota, Racial Disparities, and Epigenetic Mechanisms

Prostate cancer (PCa) continues to be the most diagnosed cancer and the second primary cause of fatalities in men globally. There is an abundance of scientific evidence suggesting that the human microbiome, together with its metabolites, plays a crucial role in carcinogenesis and has a significant impact on the efficacy of anticancer interventions in solid and hematological cancers. These anticancer interventions include chemotherapy, immune checkpoint inhibitors, and targeted therapies. Furthermore, the microbiome can influence systemic and local immune responses using numerous metabolites such as short-chain fatty acids (SCFAs). Despite the lack of scientific data in terms of the role of SCFAs in PCa pathogenesis, recent studies show that SCFAs have a profound impact on PCa progression. Several studies have reported racial/ethnic disparities in terms of bacterial content in the gut microbiome and SCFA composition. These studies explored microbiome and SCFA racial/ethnic disparities in cancers such as colorectal, colon, cervical, breast, and endometrial cancer. Notably, there are currently no published studies exploring microbiome/SCFA composition racial disparities and their role in PCa carcinogenesis. This review discusses the potential role of the microbiome in PCa development and progression. The involvement of microbiome-derived SCFAs in facilitating PCa carcinogenesis and their effect on PCa therapeutic response, particularly immunotherapy, are discussed. Racial/ethnic differences in microbiome composition and SCFA content in various cancers are also discussed. Lastly, the effects of SCFAs on PCa progression via epigenetic modifications is also discussed.

Probing the Relationship Between the Human Gut Microbiome and Prospects of Prostate Cancer: A Systematic Review

Prostate neoplasia is one of the most commonly occurring neoplasias in males and has a high mortality rate. Prostate cancer (PCA) risk factors include tall stature, male sex, known family history, obesity, high blood pressure, lack of fitness, higher levels of testosterone for a long time, increasing age, and ethnicity are well known. The association and role of the gut microbiota in different diseases in our body have been highlighted recently. Therefore, finding the influence of gut microbiota on the prostatic cells can be useful for preventing prostatic neoplasia and/or reducing its severity. We aimed to assess its impact on PCA risk. We thoroughly searched databases for the relevant literature for our systematic review. The final research papers analyzed how bacteria played a role in the risk of PCA, either through inflammation or the production of metabolites that increase/decrease the risk of PCA. Based on the studies reviewed, we found that some gut bacteria play a role in the formation of PCA. In contrast, some bacteria can help prevent PCA, but the metabolism of the dietary components is the major factor for PCA.