TRAF6 regulates proliferation of stromal cells in the transition and peripheral zones of benign prostatic hyperplasia via Akt/mTOR signaling

Exploring the Enigma of 5-ARIs Resistance in Benign Prostatic Hyperplasia: Paving the Path for Personalized Medicine

PURPOSE OF REVIEW

Despite the widespread utilization of 5-alpha reductase inhibitors (5-ARIs) for managing benign prostatic hyperplasia (BPH), certain BPH patients exhibit unresponsiveness to 5-ARIs therapy. This paper provides a comprehensive overview of the current perspectives on the mechanisms of 5-ARIs resistance in BPH patients and integrates potential biomarkers and underlying therapeutic options for 5-ARIs resistance. These findings may facilitate the development of novel or optimize more effective treatment options, and promote personalized medicine for BPH.

RECENT FINDINGS

The pathways contributing to resistance against 5-ARIs in certain BPH patients encompass epigenetic modifications, shifts in hormone levels, autophagic processes, and variations in androgen receptor structures, and these pathways may ultimately be attributed to inflammation. Promisingly, novel biomarkers, including intravesical prostatic protrusion, inflammatory factors, and single nucleotide polymorphisms, may offer predictive insights into the responsiveness to 5-ARIs therapy, empowering physicians to fine-tune treatment strategies. Additionally, on the horizon, GV1001 and mTOR inhibitors have emerged as potential alternative therapeutic modalities for addressing BPH in the future. After extensive investigation into BPH's pathological processes and molecular landscape, it is now recognized that diverse pathophysiological mechanisms may contribute to different BPH subtypes among individuals. This insight necessitates the adoption of personalized treatment strategies, moving beyond the prevailing one-size-fits-all paradigm centered around 5-ARIs. The imperative for early identification of individuals prone to treatment resistance will drive physicians to proactively stratify risk and adapt treatment tactics in future practice. This personalized medicine approach marks a progression from the current standard treatment model, emerging as the future trajectory in BPH management.

Evaluation of the Antioxidant and Antiangiogenic Activity of a Pomegranate Extract in BPH-1 Prostate Epithelial Cells

Benign prostatic hypertrophy (BPH) is a noncancerous enlargement of the prostate gland that develops from hyper-proliferation of the stromal and epithelium region. Activation of pathways involving inflammation and oxidative stress can contribute to cell proliferation in BPH and tumorigenesis. Agricultural-waste-derived extracts have drawn the attention of researchers as they represent a valid and sustainable way to exploit waste production. Indeed, such extracts are rich in bioactive compounds and can provide health-promoting effects. In particular, extracts obtained from pomegranate wastes and by-products have been shown to exert antioxidant and anti-inflammatory effects. This study focused on the evaluation of the anti-angiogenic effects and chemopreventive action of a pomegranate extract (PWE) in cellular models of BPH. In our experimental conditions, we observed that PWE was able to significantly (p < 0.001) reduce the proliferation and migration rates (up to 60%), together with the clonogenic capacity of BPH-1 cells concomitantly with the reduction in inflammatory cytokines (e.g., IL-6, PGE2) and pro-angiogenic factor (VEGF-ADMA) release. Additionally, we demonstrated the ability of PWE in reducing angiogenesis in an in vitro model of BPH consisting in transferring BPH-1-cell-conditioned media to human endothelial H5V cells. Indeed, PWE was able to reduce tube formation in H5V cells through VEGF level reduction even at low concentrations. Overall, we confirmed that inhibition of angiogenesis may be an alternative therapeutic option to prevent neovascularization in prostate tissue with BPH and its transformation into malignant prostate cancer.

The Molecular Basis and Clinical Consequences of Chronic Inflammation in Prostatic Diseases: Prostatitis, Benign Prostatic Hyperplasia, and Prostate Cancer

Chronic inflammation is now recognized as one of the major risk factors and molecular hallmarks of chronic prostatitis, benign prostatic hyperplasia (BPH), and prostate tumorigenesis. However, the molecular mechanisms by which chronic inflammation signaling contributes to the pathogenesis of these prostate diseases are poorly understood. Previous efforts to therapeutically target the upstream (e.g., TLRs and IL1-Rs) and downstream (e.g., NF-κB subunits and cytokines) inflammatory signaling molecules in people with these conditions have been clinically ambiguous and unsatisfactory, hence fostering the recent paradigm shift towards unraveling and understanding the functional roles and clinical significance of the novel and relatively underexplored inflammatory molecules and pathways that could become potential therapeutic targets in managing prostatic diseases. In this review article, we exclusively discuss the causal and molecular drivers of prostatitis, BPH, and prostate tumorigenesis, as well as the potential impacts of microbiome dysbiosis and chronic inflammation in promoting prostate pathologies. We specifically focus on the importance of some of the underexplored druggable inflammatory molecules, by discussing how their aberrant signaling could promote prostate cancer (PCa) stemness, neuroendocrine differentiation, castration resistance, metabolic reprogramming, and immunosuppression. The potential contribution of the IL1R-TLR-IRAK-NF-κBs signaling molecules and NLR/inflammasomes in prostate pathologies, as well as the prospective benefits of selectively targeting the midstream molecules in the various inflammatory cascades, are also discussed. Though this review concentrates more on PCa, we envision that the information could be applied to other prostate diseases. In conclusion, we have underlined the molecular mechanisms and signaling pathways that may need to be targeted and/or further investigated to better understand the association between chronic inflammation and prostate diseases.

6-Paradol Alleviates Testosterone-Induced Benign Prostatic Hyperplasia in Rats by Inhibiting AKT/mTOR Axis

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common disease among elderly men. Its pharmacological treatment is still unsatisfactory. 6-Paradol (6-PD) is an active metabolite found in many members of the Zingiberaceae family. It was reported to possess anti-proliferative, antioxidant, and anti-inflammatory activities. The present study aimed at exploring the potential of 6-PD to inhibit testosterone-induced BPH in rats as well as the probable underlying mechanism.

METHODS

Male Wistar rats were divided into 6 groups and treated as follows: Group 1 (control group) received vehicles only, Group 2 testosterone only, Groups 3 and 4 received 6-PD (2.5 and 5.0 mg/kg; respectively) and testosterone, and Group 6 received finasteride and testosterone.

RESULTS

Daily treatment of animals with 6-PD at the two dose levels of 2.5 and 5 mg/kg significantly ameliorated a testosterone-induced rise in prostate index and weight. This was confirmed by histological examinations of prostatic tissues that indicated a reduction in the pathological changes as well as inhibition of the rise in glandular epithelial height in 6-PD treated rats. Immunohistochemical investigations showed that 6-PD prevented the up-regulation of cyclin D1 induced by testosterone injections. Further, 6-PD significantly modulated mRNA expression of both Bcl2 and Bax in prostate tissues of testosterone-treated rats in favor of anti-proliferation. It also showed antioxidant activities as evidenced by inhibition of accumulation of malondialdehyde (MDA) and exhaustion of catalase (CAT) activity. In addition, 6-PD displayed significant anti-inflammatory activities as it prevented up-regulation of interleukin-6 (IL-6) and nuclear factor kappa B (NF-κB). Immunoblotting analysis revealed that 6-PD significantly inhibited testosterone-induced activation of AKT and mTOR in prostate tissues.

CONCLUSIONS

6-PD protects against testosterone-induced BPH in rats. This can be attributed, at least partly, to its antiproliferative, antioxidant, and anti-inflammatory properties as well as its ability to inhibit activation of the AKT/mTOR axis.

A Systemic Review and Meta-analysis of Transabdominal Intravesical Prostatic Protrusion Assessment in Determining Bladder Outlet Obstruction and Unsuccessful Trial Without Catheter

CONTEXT

Urodynamic study (UDS) provides the most objective assessment of bladder outlet obstruction (BOO) but is impractical to be recommended routinely in outpatient services. Intravesical prostatic protrusion (IPP) had been described to obstruct urinary flow by creating an anatomical ball-valve effect, but there remains a lack of pooled evidence that can objectively correlate with BOO in benign prostatic hyperplasia.

OBJECTIVE

To update the current evidence on the predictive role of IPP in determining BOO and unsuccessful trial without catheter (TWOC).

EVIDENCE ACQUISITION

A comprehensive literature search was performed to identify studies that evaluated IPP in diagnosing UDS-determined BOO and TWOC. The search included the PubMed/MEDLINE, EMBASE, and Cochrane Library up to January 2021. An updated systemic review and meta-analysis was performed.

EVIDENCE SYNTHESIS

A total of 18 studies with 4128 patients were examined. Eleven studies with 1478 patients examined the role of IPP in UDS-determined BOO. The pooled area under the curve (AUC) was 0.83 (95% confidence interval [CI]: 0.79-0.86), and at a cut-off of >10 mm, the sensitivity (Sn) and specificity (Sp) were 0.71 (95% CI: 0.61-0.78) and 0.77 (95% CI: 0.68-0.84), respectively. The probability-modifying plot revealed positive and negative likelihood ratios of 3.34 (95% CI: 2.56-4.36) and 0.35 (95% CI: 0.26-0.45), respectively. Seven studies with 2650 patients examined IPP in predicting unsuccessful TWOC, with a pooled AUC of 0.74 (95% CI: 0.70-0.84), with Sn of 0.51 (95% CI: 0.43-0.60) and Sp of 0.79 (95% CI: 0.73-0.84) at an IPP cut-off of >10 mm. Five studies compared prostate volume (PV) and IPP and revealed a lower AUC of PV at 0.71 (95% CI: 0.67-0.75), which was an inferior parameter in diagnosing BOO (p < 0.001).

CONCLUSIONS

This systemic review provided evidence that IPP is a reliable clinical parameter that correlates strongly with underlying BOO and unsuccessful TWOC.

PATIENT SUMMARY

In this review, we comprehensively reviewed all the literature to date on evaluating the clinical utility of intravesical prostatic protrusion (IPP). We have demonstrated that IPP correlates strongly with urodynamic study (UDS)-determined bladder outlet obstruction and failure of trial without catheter (TWOC). Outpatient IPP measurement is a quick, inexpensive, and reproducible clinical parameter that can determine the severity of benign prostatic hyperplasia. The clinical role of IPP in predicting failure of TWOC selects patients who are best treated with aggressive surgical approaches rather than conservative medical therapies. More importantly, IPP can facilitate the discriminatory use of invasive UDS, reserved for patients with a strong suspicion of concomitant detrusor abnormalities.

Exosomes from mesenchymal stem cells expressing microribonucleic acid-125b inhibit the progression of diabetic nephropathy via the tumour necrosis factor receptor-associated factor 6/Akt axis

Diabetic nephropathy (DN) seriously threatens the health of patients with diabetes. Moreover, it has been reported that mesenchymal stem cell (MSC)-derived exosomal miRNAs can modulate the progression of multiple diseases, including DN. It has been suggested that miR-125b is involved in DN. However, the biological functions of exosomal miRNAs, especially miR-125b, in DN are still unclear. To establish a DN model in vitro, we used a model of human embryonic kidney epithelial cells (HKCs) injury induced by high glucose (HG). Then, miR-125b was delivered to the model cells in vitro via MSC-derived exosomes (MSC-Exos), and the effect of exosomal miR-125b on HKCs apoptosis was evaluated by flow cytometry. qRT-PCR or western blotting was performed to measure miR-125b or tumour necrosis factor receptor-associated factor 6 (TRAF6) expression in HKC. The effect of MSC-Exos on HKCs apoptosis after miR-125b knockdown was determined by flow cytometry. Moreover, dual-luciferase reporter assays were used to determine the targeting relationship between miR-125b and TRAF6 in HKCs. Our data revealed that MSC-Exos increased HG-induced autophagy in HKCs and reversed HKCs apoptosis. Moreover, our study found that miR-125b was enriched in MSC-Exos and directly targeted TRAF6 in HKCs. In addition, exosomally transferred miR-125b inhibited the apoptosis of HG-treated HKCs by mediating Akt signalling. In summary, MSC-derived exosomal miR-125b induced autophagy and inhibited apoptosis in HG-treated HKCs via the downregulation of TRAF6. Therefore, our study provided a new idea for DN treatment.

Three-dimensional measurement and analysis of benign prostatic hyperplasia

Background

The volume and thickness of intravesical prostatic protrusion and other characteristics of benign prostatic hyperplasia have not been investigated. We determine the effects of age and prostate volume on anatomical features of benign prostatic hyperplasia using three-dimensional measurement in this study.

Methods

This retrospective study included a total of 98 patients with benign prostatic hyperplasia. Three-dimensional models of prostate, central gland, peripheral zone, intravesical prostatic protrusion, prostatic urethra and bladder were reconstructed according to pelvic T2-weighted magnetic resonance imaging of these patients. The models were used to measure the intravesical prostatic protrusion volume, intravesical prostatic protrusion thickness, intravesical prostatic protrusion index, intravesical prostatic protrusion, prostate volume, peripheral zone volume, peripheral zone thickness, peripheral zone index, prostatic urethra thickness, the angle and distance of distal prostatic urethra with regard to coronal plane and sagittal plane and so on.

Results

Intravesical prostatic protrusion volume, intravesical prostatic protrusion thickness and peripheral zone volume of prostate volume >80 mL group were significantly higher than these in prostate volume <80 mL group (P<0.001, 0.01, 0.01, respectively). These parameters significantly increased with age (P<0.001, 0.01, 0.05, respectively). Peripheral zone index was significantly lower of prostate volume >80 mL group than these in prostate volume <80 mL group (P<0.05). Peripheral zone index significantly decreased with age (P<0.01). Intravesical prostatic protrusion index had no significant difference in all age groups. Peripheral zone thickness and prostatic urethra thickness had no significant difference in all groups. The distance and angle of distal prostatic urethra prostatic urethra with regard to coronal plane were significantly higher than these with regard to sagittal plane (both P<0.001).

Conclusions

The rearward slope of the prostatic urethra is greater than the left or right offset during the process of benign prostatic hyperplasia. Three-dimensional measurement provides good supports for further clinical and scientific research.

Effects of shRNA-mediated silencing of PDE5A3 on intracellular cGMP and free Ca2+ levels and human prostate smooth muscle cell proliferation from benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS) is a common disease among elderly men, for which safe and effective treatment strategies remain limited. The aim of the present study was to explore the potential effects of phosphodiesterase 5A3 (PDE5A3) silencing on human prostate smooth muscle cells (HPSMCs). HPSMCs were initially obtained from patients with BPH/LUTS. Short hairpin RNA (shRNA) targeting the PDE5A3 gene was subsequently transfected into cultured HPSMCs. The expression of PDE5A3 was measured using reverse transcription-quantitative PCR and western blotting. cGMP levels were then measured using western blotting and immunocytochemical staining and intracellular Ca²⁺ concentration was measured using rhod2-AM in HPSMCs after transfection. HPSMC proliferation was also observed within 4 days. Cells transfected with PDE5A3-shRNA2 exhibited the most notable decline in PDE5A3 expression compared with that in the Control or NC groups. cGMP levels in HPSMCs transfected with PDE5A3-shRNA2 was significantly increased compared with those in the Control or NC groups, whereas intracellular Ca²⁺ concentrations in cells in the PDE5A3-shRNA2 group were decreased compared with that in the Control or NC groups. The proliferation of HPSMCs in the PDE5A3-shRNA2 group was also inhibited compared with that in the Control or NC groups after 72 h of culture. In conclusion, shRNA-mediated silencing of PDE5A3 was able to increase the levels of cGMP whilst reducing the concentration of Ca²⁺ in HPSMCs, in turn suppressing their proliferation. These findings may potentially provide a novel therapeutic target for treating BPH/LUTS.

TRAF6 Promotes Gastric Cancer Cell Self-Renewal, Proliferation, and Migration

Gastric cancer is the third most common type of tumor associated with death. TRAF6 belongs to the tumor necrosis factor receptor-associated factor family and has been demonstrated to be involved in tumor progression in various cancers. However, the exact effect of TRAF6 on gastric cancer stem cells has not been extensively studied. In this study, abnormal expression of TRAF6 was found in gastric cancer tissues. Overexpression of TRAF6 enhanced proliferation and migration, and TRAF6 knockdown reversed this phenomenon in gastric cancer cells. Moreover, TRAF6 may inhibit differentiation and promote stemness and epithelial-mesenchymal transition (EMT). Transcriptome profiles revealed 701 differentially expressed genes in the wild-type group and the TRAF6 knockout group. Potential molecules associated with cell proliferation and migration were identified, including MAPK, FOXO, and IL-17. In conclusion, TRAF6 is a significant factor promoting proliferation and migration in gastric cancer cells and may provide a new target for the accurate treatment of gastric cancer.

Integrative multiplatform molecular profiling of benign prostatic hyperplasia identifies distinct subtypes

Benign prostatic hyperplasia (BPH), a nonmalignant enlargement of the prostate, is among the most common diseases affecting aging men, but the underlying molecular features remain poorly understood, and therapeutic options are limited. Here we employ a comprehensive molecular investigation of BPH, including genomic, transcriptomic and epigenetic profiling. We find no evidence of neoplastic features in BPH: no evidence of driver genomic alterations, including low coding mutation rates, mutational signatures consistent with aging tissues, minimal copy number alterations, and no genomic rearrangements. At the epigenetic level, global hypermethylation is the dominant process. Integrating transcriptional and methylation signatures identifies two BPH subgroups with distinct clinical features and signaling pathways, validated in two independent cohorts. Finally, mTOR inhibitors emerge as a potential subtype-specific therapeutic option, and men exposed to mTOR inhibitors show a significant decrease in prostate size. We conclude that BPH consists of distinct molecular subgroups, with potential for subtype-specific precision therapy.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.