Correlation between 5-α reductase type 2 protein expression and methylation of 5-α reductase type 2 promotor gene of benign prostatic hyperplasia

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.

Upregulation of mir-1199-5p is associated with reduced type 2 5-α reductase expression in benign prostatic hyperplasia

Background

5-α reductase inhibitors (5-ARIs) are first-line drugs for managing benign prostatic hyperplasia (BPH). Unfortunately, some patients do not respond to 5-ARI therapy and may even show worsening symptoms. The decreased expression of steroid 5-α reductase type 2(SRD5A2) in BPH tissues may explain the failure of 5-ARI therapy, however, the mechanisms underlying SRD5A2 decreased remained unelucidated.

Objectives

To investigate microRNA-mediated regulation of the expression of SRD5A2 resulting in 5-ARI therapy failure.

Materials and methods

The expression of SRD5A2 and microRNAs in BPH tissues and prostate cells were detected by immunohistochemistry, western blotting, and quantitative real-time PCR. Dual-luciferase reporter assay was performed to confirm that microRNA directly combine to SRD5A2 mRNA. The apoptosis of prostatic cells was detected by flow cytometry.

Results

SRD5A2 expression was variable; it was negative, weak, and strong in 13.6%, 28.8%, and 57.6% of BPH tissues respectively. The normal human prostatic epithelial cell line RWPE-1 strongly expressed SRD5A2, whereas the immortalized human prostatic epithelial cell line BPH-1 weakly expressed SRD5A2. miR-1199-5p expression was remarkably higher in BPH-1 than in RWPE-1 cells(P<0.001), and miR-1199-5p expression was significantly upregulated in BPH tissues with negative SRD5A2 expression than those with positive SRD5A2 expression. Transfection of miR-1199-5p mimics in RWPE-1 cells led to a marked decrease in SRD5A2 expression, whereas miR-1199-5p inhibitor increased SRD5A2 expression in BPH-1 cells. Dual-luciferase reporter assay showed that miR-1199-5p could bind the 3′untranslated region of SRD5A2 mRNA. miR-1199-5p also decreased the RWPE-1 sensibility to finasteride, an inhibitor of SRD5A2.

Conclusion

Our results show that SRD5A2 expression varies in BPH tissues and miR-1199-5p might be one of the several factors contributing to differential SRD5A2 expression in BPH patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-01121-5.

METTL3 promotes prostatic hyperplasia by regulating PTEN expression in an m6A-YTHDF2-dependent manner

Uncontrolled epithelial cell proliferation in the prostate transition zone and the hyper-accumulation of mesenchymal-like cells derived from the epithelial-mesenchymal transition (EMT) of prostatic epithelium are two key processes in benign prostatic hyperplasia (BPH). m⁶A RNA modification affects multiple cellular processes, including cell proliferation, apoptosis, and differentiation. In this study, the aberrant up-regulation of methylase METTL3 in BPH samples suggests its potential role in BPH development. Elevated m⁶A modification in the prostate of the BPH rat was partially reduced by METTL3 knockdown. METTL3 knockdown also partially reduced the prostatic epithelial thickness and prostate weight, significantly improved the histological features of the prostate, inhibited epithelial proliferation and EMT, and promoted apoptosis. In vitro, METTL3 knockdown decreased TGF-β-stimulated BPH-1 cell proliferation, m⁶A modification, and EMT, whereas promoted cell apoptosis. METTL3 increased the m⁶A modification of PTEN and inhibited its expression through the reading protein YTHDF2. PTEN knockdown aggravated the molecular, cellular, and pathological alterations in the prostate of BPH rats and amplified TGF-β-induced changes in BPH-1 cells. More importantly, PTEN knockdown partially abolished the improving effects of METTL3 knockdown both in vivo and in vitro. In conclusion, the level of m⁶A modification is elevated in BPH; the METTL3/YTHDF2/PTEN axis disturbs the balance between epithelial proliferation and apoptosis, promotes EMT, and accelerates BPH development in an m⁶A modification-related manner.

Dutasteride add-on treatment to tadalafil for patients with benign prostatic enlargement is similarly effective as dutasteride add-on treatment to alpha blocker: a propensity-score matching analysis

PURPOSE

To investigate the efficacy of dutasteride add-on treatment to tadalafil in patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic enlargement (BPE).

METHODS

A prospective study was conducted in patients with BPE who had not been satisfied with tadalafil monotherapy for more than 3 months. Inclusion criteria were prostate volume (PV) ≥ 30 ml and IPSS ≥ 8 or QOL index ≥ 3 under administration of tadalafil without anticholinergic agent. Before and 24 weeks after dutasteride add-on treatment to tadalafil, we assessed IPSS, overactive bladder symptom score (OABSS), serum PSA and testosterone, and uroflowmetry (UFM) to compare these parameters before and after dutasteride add-on treatment. Using a propensity-score matching analysis, the efficacy of dutasteride add-on treatment to tadalafil was compared with the previous study of dutasteride add-on treatment to alpha blocker.

RESULTS

Of 52 patients who were enrolled in this study, 48 patients completed the study (mean age: 72 ± 5 years old). Dutasteride add-on treatment to tadalafil significantly improved IPSS (from 16.4 ± 5.2 to 13.3 ± 6.4) and IPSS-QOL (from 4.0 ± 1.2 to 3.3 ± 1.1), and reduced PV from 55 ± 26 to 39 ± 22 ml. Propensity-score matching identified 42 matched pairs of patients. The improvement rate of IPSS and reduction rate of PV were similar between patients treated with dutasteride add-on treatment to tadalafil and dutasteride add-on treatment to alpha blocker. The logistic regression analysis showed that PV at baseline and reduction rate of PV after treatment were associated with the effective symptomatic outcome.

CONCLUSIONS

The dutasteride add-on is a reasonable treatment option for male patients with LUTS who are not satisfied with tadalafil monotherapy.

Risk factors for failure of long-term dutasteride add-on treatment to alpha-adrenergic antagonist for patients with lower urinary tract symptoms and benign prostatic enlargement

PURPOSE

To identify the clinical factors resulting in the failure of dutasteride add-on treatment to alpha-adrenergic antagonist for patients with lower urinary tract symptoms and benign prostatic enlargement (BPE).

METHODS

We retrospectively surveyed the patient cohort who had been enrolled in the study of dutasteride add-on treatment to alpha-adrenergic antagonist from December 2009 to November 2011. Treatment failure was defined as receiving surgery for BPE or requiring intermittent catheterization or permanent bladder catheter for urinary retention or huge postvoid residual urine. Clinical parameters before dutasteride treatment were compared between the successful and failed group.

RESULTS

Of 92 patients, 23 (25%) were defined as treatment failure at 7-109 months (mean: 38 months) after dutasteride add-on treatment. In the failed group, the patient' age was younger (71.6  ±  6.8 vs 75.4  ±  8.4, p = 0.033), prostatic volume (PV) was larger (76  ±  41 vs 49  ±  26 ml, p = 0.005), voiding efficiency was lower (54  ±  27 vs 68  ±  24%, p = 0.045) and bladder outlet obstruction index was higher (73  ±  30 vs 48  ±  30, p = 0.015). The cox proportional-hazards model indicated that only intravesical prostatic protrusion (IPP) was associated with treatment failure. Non-failure rate at 3 years after dutasteride add-on treatment was 89% with patients of IPP < 13 mm versus 51% with those of IPP ≥ 13 mm (p < 0.001).

CONCLUSION

IPP ≥ 13 mm is the risk factor resulting in the failure of dutasteride add-on treatment to alpha-adrenergic antagonist. This kind of information should be provided to the patients early in the clinical practice so that they could consider the necessity of BPE surgery in the long run.

Epigenetic reprogramming during prostate cancer progression: A perspective from development

Conrad Waddington's theory of epigenetic landscape epitomize the process of cell fate and cellular decision-making during development. Wherein the epigenetic code maintains patterns of gene expression in pluripotent and differentiated cellular states during embryonic development and differentiation. Over the years disruption or reprogramming of the epigenetic landscape has been extensively studied in the course of cancer progression. Cellular dedifferentiation being a key hallmark of cancer allow us to take cues from the biological processes involved during development. Here, we discuss the role of epigenetic landscape and its modifiers in cell-fate determination, differentiation and prostate cancer progression. Lately, the emergence of RNA-modifications has also furthered our understanding of epigenetics in cancer. The overview of the epigenetic code regulating androgen signalling, and progression to aggressive neuroendocrine stage of PCa reinforces its gene regulatory functions during the development of prostate gland as well as cancer progression. Additionally, we also highlight the clinical implications of cancer cell epigenome, and discuss the recent advancements in the therapeutic strategies targeting the advanced stage disease.

Azasteroids from diosgenin: Synthesis and evaluation of their antiproliferative activity

In this work, we report the synthesis of two new azasteroids through the modification of the A and B rings of diosgenin 1. The 4-azasteroid derivative 12 was prepared in three steps using the α,β-insaturated-3-keto compound 11 as a precursor, which was first oxidized with KMnO4/KIO4 followed by an oxidative cleavage of ring A, and subsequently cyclized with an ammonium salt, under focused microwave irradiation for a short time of 3 min. A second azasteroid was synthesized, for which the key step was the Beckmann rearrangement of ring B of the oxime 16, affording the lactam-type enamide 17 in good yield. The methodologies developed for the synthesis of the precursors derivatives 10 and 11 contribute to improved yields, compared to those reported in the literature. The biological activity of the azasteroidal compounds 12 and 17 and their precursors has been evaluated in cervical cancer cells (HeLa), colon (HCT-15), and triple negative breast cancer (MDA-MB-231) lines.

Methylated CpG dinucleotides in the 5-α reductase 2 gene may explain finasteride resistance in benign prostatic enlargement patients

The inhibition of 5-α reductase type 2 (SRD5A2) by finasteride is commonly used for the management of urinary obstruction resulting from benign prostatic enlargement (BPE). Certain BPE patients showing no SRD5A2 protein expression are resistant to finasteride therapy. Our previous work showed that methylated cytosine-phosphate-guanine (CpG) islands in the SRD5A2 gene might account for the absence or reduction of SRD5A2 protein expression. Here, we found that the expression of the SRD5A2 protein was variable and that weak expression of the SRD5A2 protein (scored 0–100) occurred in 10.0% (4/40) of benign adult prostates. We showed that the expression of SRD5A2 was negatively correlated with DNA methyltransferase 1 (DNMT1) expression. In vitro SRD5A2-negative BPH-1 cells were resistant to finasteride treatment, and SRD5A2 was re-expressed in BPH-1 cells when SRD5A2 was demethylated by 5-Aza-2'-deoxycytidine (5-Aza-CdR) or N-phthalyl-L-tryptophan (RG108). Furthermore, we determined the exact methylation ratios of CpG dinucleotides in a CpG island of SRD5A2 through MassArray quantitative methylation analysis. Ten methylated CpG dinucleotides, including four CpG dinucleotides in the promoter and six CpG dinucleotides in the first exon, were found in a CpG island located from −400 bp to +600 bp in SRD5A2, which might lead to the silencing of SRD5A2 and the absence or reduction of SRD5A2 protein expression. Finasteride cannot exert a therapeutic effect on patients lacking SRD5A2, which may partially account for the resistance to finasteride observed in certain BPE patients.