Does the prostatic vascular system contribute to the development of benign prostatic hyperplasia?

Propensity score-matched evaluation of palliative transurethral resection and holmium laser enucleation of the prostate for bladder outlet obstruction in patients with prostate cancer

BACKGROUND

While transurethral resection of the prostate (TURP) is the standard-of-care, Holmium laser enucleation of the prostate (HoLEP) is widely accepted as a size-independent method for surgical treatment of patients with lower urinary tract symptoms (LUTS) secondary to bladder outlet obstruction (BOO). However, in an ageing society an increasing number of patients presents with BOO due to locally advanced prostate cancer. There is currently no guidelines recommendation as to the enucleation or resection technique. Therefore, we compared intraoperative performance, postoperative outcomes, and safety for palliative (p)TURP and (p)HoLEP.

METHODS

We conducted a retrospective, propensity score-matched analysis of 1373 and 2705 men who underwent TURP or HoLEP for LUTS/BOO between 2014 and 2021, respectively. Patients were matched for age, prostate size and preoperative international prostate symptom score (IPSS). Patients were stratified by technique and groups were compared for perioperative parameters, safety, and functional outcomes.

RESULTS

While postoperative symptoms and urodynamic parameters improved irrespective of technique, we report significantly increased resection and enucleation times for palliative indication. For corresponding efficiency parameters, we observed a two-fold higher surgical performance (g/min) for both techniques in patients without prostate cancer. While adverse events were comparable between groups, we found a two-fold higher hemoglobin drop in palliative patients.

CONCLUSIONS

Currently, there is no standard-of-care for patients with BOO and locally advanced prostate cancer. Our data show that both TURP and HoLEP offer adequate symptom improvement and comparable safety profiles. While HoLEP is feasible even in larger prostates, both procedures become more difficult in patients with prostate cancer. Taken together, this study covers an important gap in current literature, helping urological surgeons to make evidence-based decisions for the benefit of their patients.

The role of inflammatory processes and zinc levels in prostatic enlargement among Iraqi samples

This study aimed to investigate the role of inflammatory processes in benign prostatic enlargement among men with elevated prostate-specific antigen (PSA) levels without a history of prostatic disease. Additionally, we aimed to examine the influence of serum zinc levels on prostate volume. We investigated the associations between systemic inflammatory markers, serum PSA, and serum zinc levels in 48 men without a history of prostatic disease, aged between 60-72 years, and 30 healthy men in the same age range. Data collection occurred between 1/2/2022 to 1/10/2022. The results are presented as mean values ± standard error (SE), and statistical significance was determined at p≤0.05. The levels of sIL-8 (P: 44.295±1.002, C: 1.404±0.2562), IL-6 (P: 7.406±0.5632, C: 4.468±0.830), CRP (P: 14.765±0.565, C: 6.267±0.538), increased significantly in patients with high PSA, while zinc levels (P: 92.305±2.8235, C: 114.565±8.861) decreased in the patient group. Regarding white blood cell (WBC) parameters, patients exhibited a significant increase in WBC total count (P: 12995.00±488.47, C: 7713.333±777.778), neutrophil % (P: 69.450±1.619, C: 51.200±1.826), lymphocyte % (P: 39.50±2.024, C: 30.867±1.268), and NLR (2.013±0.105). Conversely, there were no significant differences in eosinophil % (P: 3.450±0.4558, C: 3.267±0.5297), basophil % (P: 0.300±0.105, C: 0.267±1182), or monocyte % (P: 3.450±0.4558, C: 3.267±0.5297) between the two groups. In men without known prostatic illness, increased PSA was linked to markers of systemic inflammation. The results indicate the role of inflammatory processes in increasing the size of the prostate gland, as evidenced by the increased levels of immune markers like white blood cells and interleukins, along with the influence of zinc. Future research is required to determine how these markers relate to the development and incidence of prostate cancer.

Holmium laser enucleation of the prostate: A truly size-independent method?

OBJECTIVES

To evaluate the impact of prostate size on functional outcomes and perioperative morbidity, we analyzed patients undergoing holmium laser enucleation of the prostate (HoLEP) for lower urinary tract symptoms (LUTS). As LUTS secondary to benign prostatic obstruction (BPO) are a chronic progressive disease, prevalence and prostate size increase with age. HoLEP is a size-independent method for surgical treatment of LUTS/BPO and can be offered in medication-refractory patients with durable long-term results and reduced perioperative morbidity.

METHODS

We retrospectively collected data of 852 patients who underwent HoLEP for LUTS secondary to BPO between 2014-2018. Patients were divided into group 1 (≤60 cc), group 2 (>60 < 120 cc), group 3 (≥120 cc). Perioperative parameters, safety and short-term functional outcomes were assessed and analyzed.

RESULTS

Patients in group 3 were significantly older and showed a significantly higher median prostate-specific antigen level. Perioperative parameters, such as enucleation time and morcellation time significantly differed in favor of smaller prostate sizes, while enucleation and morcellation speed showed favorable results for larger prostate sizes. Larger prostates ≥120 cc showed a significantly higher postoperative drop in hemoglobin. However, patients did not differ in postoperative functional outcomes or Clavien-Dindo grade ≥II complications (4.8% of all patients [41/852]). There was no difference in perioperative complications between all groups (P = 0.760).

CONCLUSION

While larger prostates take significantly longer to operate on, postoperative functional outcomes show no difference between all sizes. In conclusion, HoLEP is a size-independent and effective method for surgical treatment of LUTS/BPO in prostates ≥30 cc.

Serenoa repens and Urtica dioica Fixed Combination: In-Vitro Validation of a Therapy for Benign Prostatic Hyperplasia (BPH)

Benign prostatic hyperplasia (BPH) is an age-related chronic disorder, characterized by the hyperproliferation of prostatic epithelial and stromal cells, which drives prostate enlargement. Since BPH aetiology and progression have been associated with the persistence of an inflammatory stimulus, induced both by Nuclear Factor-kappa B (NF-κB) activation and reactive oxygen species (ROS) production, the inhibition of these pathways could result in a good tool for its clinical treatment. This study aimed to evaluate the antioxidant and anti-inflammatory activity of a combined formulation of Serenoa repens and Urtica dioica (SR/UD) in an in vitro human model of BPH. The results confirmed both the antioxidant and the anti-inflammatory effects of SR/UD. In fact, SR/UD simultaneously reduced ROS production, NF-κB translocation inside the nucleus, and, consequently, interleukin 6 (IL-6) and interleukin 8 (IL-8) production. Furthermore, the effect of SR/UD was also tested in a human androgen-independent prostate cell model, PC3. SR/UD did not show any significant antioxidant and anti-inflammatory effect, but was able to reduce NF-κB translocation. Taken together, these results suggested a promising role of SR/UD in BPH and BPH-linked disorder prevention.

Prostatic hyperplasia: Vascularization, hemodynamic and hormonal analysis of dogs treated with finasteride or orchiectomy

As a consequence of a hormonal imbalance, Prostatic Hyperplasia (PH) is characterized by increased prostate volume, along with higher local angiogenesis and vascularization. Orchiectomy is the common treatment for dogs, however it is not an option for breeding animals. Thus, finasteride arises as the drug of choice for stud dogs. Therefore, the aim of this study was to evaluate the effects of orchiectomy or finasteride therapies on hormonal and vascular dynamics of PH dogs. Fifteen dogs, aged 6–13 years were assigned to: Untreated Group (dogs diagnosed with PH—n = 5), Finasteride treated group (PH dogs treated with finasteride—n = 5) and Orchiectomy treated group (PH dogs submitted to orchiectomy–n = 5). Evaluations were performed in a monthly interval (first day of treatment; after 30 and 60 days). Doppler ultrasonography was performed to measure prostatic volume, vascularization and hemodynamic profile of prostatic artery. Dihydrotestosterone, estrogen and testosterone concentrations were measured. At day 60, prostatic biopsy was performed for histological, immunohistochemical and qPCR analysis for VEGF-A expression. At day 60, vascularization score was higher in untreated compared to treated groups (finasteride and orchiectomy). Furthermore, VEGF-A expression was lower in the Orchiectomy Treated Group, but VEGF-A was immunohistochemically lower in both treated groups (finasteride and orchiectomy) compared to the Untreated Group. The efficiency of finasteride treatment in reducing clinical signs, prostate volume and vascularization appears to be similar to orchiectomy. In conclusion, both PH medical and surgical therapy lead to reduction in prostate dimension and VEGF-A expression and, consequently, lower local vascularization. However, orchiectomy promotes marked hormonal changes, which ultimately lead to prostate atrophy.

Effects of silodosin and tadalafil on bladder dysfunction in spontaneously hypertensive rats: Possible role of bladder blood flow

OBJECTIVES

To investigate the effects of an alpha1-adrenoceptor antagonist, silodosin, or a phosphodiesterase type 5 inhibitor, tadalafil, on bladder overactivity in spontaneously hypertensive rats.

METHODS

Twelve-week-old male spontaneously hypertensive rats were perorally administered silodosin (100 µg/kg), tadalafil (2 or 10 mg/kg) or vehicle once daily for 6 weeks. Wistar rats were used as normotensive controls and were treated with the vehicle. At 18-weeks-old, the effects of silodosin or tadalafil on blood pressure, bladder blood flow, urodynamic parameters (i.e. micturition frequency, urine output, inter-contraction interval, maximum voiding pressure, single voided volume and post-voiding residual urine volume), and bladder tissue levels of malondialdehyde, interleukin-6 and tumor necrosis factor-alpha were measured.

RESULTS

A significant increase in blood pressure, micturition frequency and bladder tissue levels of malondialdehyde, interleukin-6 and tumor necrosis factor-alpha was noted in spontaneously hypertensive rats. The single voided volume, bladder capacity and bladder blood flow were significantly lower in the spontaneously hypertensive rats than in the Wistar rats. Treatment with silodosin and the higher dose of tadalafil improved the urodynamic parameters, bladder blood flow and bladder tissue levels of malondialdehyde in the spontaneously hypertensive rats without affecting the blood pressure and bladder tissue levels of interleukin-6 and tumor necrosis factor-alpha.

CONCLUSIONS

Treatment with silodosin or tadalafil might improve hypertension-related bladder overactivity, as shown in spontaneously hypertensive rats through an improvement in the bladder blood flow and bladder tissue levels of oxidative stress.

Development of Quantitative Detection Assays for CYR61 as a New Marker for Benign Prostatic Hyperplasia

Among urological diseases, benign prostatic hyperplasia (BPH) exhibits a high morbidity rate, afflicting approximately 50% of men older than age 50 years. Despite intense research efforts over the past decades, the etiology and mechanisms of BPH progression are only poorly understood. Employing oligonucleotide microarrays, the authors analyzed the gene expression profiles in normal and BPH prostate samples and found that CYR61, an immediate early gene, is markedly overexpressed in BPH. To quantify cellular CYR61 mRNA expression directly, the authors developed an assay using branched-chain DNA (bDNA) technology. A human prostatic epithelial cell line, BRF-55T, derived from a BPH patient, was treated with fetal bovine serum to stimulate gene expression, and then the induction profile of the CYR61 mRNA in these serum-stimulated cells was quantitated using both bDNA and quantitative reverse transcriptase–PCR (RT-PCR). The results obtained with the 2 detection systems were found to be very similar. The bDNA assay was also found to be sensitive and highly reproducible. To the authors’knowledge, this is the first time that identifying CYR61 as a novel marker for BPH and its quantitation has been reported. These detection methods not only may be useful for diagnostic purposes but may also be used to identify suppressors of CYR61 expression for BPH therapy employing high-throughput screening assays.

Prostatic Artery Embolization (PAE) for Symptomatic Benign Prostatic Hyperplasia (BPH): Part 1, Pathological Background and Clinical Implications

Pathological features of benign prostatic hyperplasia (BPH) dictate various responses to prostatic artery embolization (PAE). Typically, BPH originates in the transition zone and periurethral region, where should be considered the primary target area in PAE procedures. Given that histological heterogeneity of components in hyperplasia nodules, epithelial or stromal, identifying the more responsive nodules to PAE will have clinical implications. Since some lower urinary tract symptoms (LUTS) in patients with BPH are usually related to bladder outlet obstruction-induced changes in bladder function rather than to outflow obstruction directly, proper selection of candidate patients prior to PAE is of great clinical importance. BPH is a typical chronic progressive condition, suggesting PAE could aim not only to relieve LUTS but also to delay or prevent the clinical progression. Awareness of the pathological background of BPH is essential for interventional radiologists to improve clinical outcomes and develop new treatment strategies in clinical practice of PAE.

Effect of pulsed electromagnetic field therapy on prostate volume and vascularity in the treatment of benign prostatic hyperplasia: a pilot study in a canine model

BACKGROUND

Benign prostatic hyperplasia (BPH) is a result of urogenital aging. Recent studies suggest that an age-related impairment of the blood supply to the lower urinary tract plays a role in the development of BPH and thus may be a contributing factor in the pathogenesis of BPH. The canine prostate is a model for understanding abnormal growth of the human prostate gland. We studied the efficacy of pulsed electromagnetic field therapy (PEMF) in dogs to modify prostate blood flow and evaluated its effect on BPH.

METHODS

PEMF (5 min, twice a day for 3 weeks) was performed on 20 dogs affected by BPH. Prostatic volume, Doppler assessment by ultrasonography, libido, semen quality, testosterone levels, and seminal plasma volume, composition and pH were evaluated before and after treatment.

RESULTS

The 3 weeks of PEMF produced a significant reduction in prostatic volume (average 57%) without any interference with semen quality, testosterone levels or libido. Doppler parameters showed a reduction of peripheral resistances and a progressive reduction throughout the trial of the systolic peak velocity, end-diastolic velocity, mean velocity, mean, and peak gradient of the blood flow in the dorsal branch of the prostatic artery. The pulsatility index and the resistance index did not vary significantly over time.

CONCLUSIONS

The efficacy of PEMF on BPH in dogs, with no side effects, suggests the suitability of this treatment in humans and supports the hypothesis that impairment of blood supply to the lower urinary tract may be a causative factor in the development of BPH.

Prostatic ischemia induces ventral prostatic hyperplasia in the SHR; possible mechanism of development of BPH

In the light of increasing evidence that benign prostatic hyperplasia is associated with cardiovascular disease, we have investigated the relationship between prostatic blood flow and prostatic hyperplasia in the spontaneously-hypertensive-rat (SHR). Twelve-week-old male SHRs were treated with nicorandil for six weeks. Wistar-Kyoto rats were used as controls. Six weeks after nicorandil treatment, blood pressure and the prostatic blood flow were estimated, and tissue levels of malondialdehyde, HIF-1α, TGF-β1, bFGF, dihydrotestosterone, and α-SMA were measured. SHRs showed significant increases in blood pressure, tissue levels of malondialdehyde, HIF-1α, TGF-β1, bFGF, α-SMA and a significant decrease in the prostatic blood flow. Although treatment with nicorandil failed to alter the blood-pressure and α-SMA, it significantly ameliorated the increased levels of malondialdehyde, HIF-1α, TGF-β1, and bFGF. There were no significant differences in tissue levels of dihydrotestosterone among any groups. These data indicate that development of prostatic hyperplasia may be associated with prostatic hypoxia, which nicorandil prevents via its effect to increase the blood flow.

White blood cell count is positively associated with benign prostatic hyperplasia

OBJECTIVES

To determine whether low-grade systemic inflammation is associated with prostatic enlargement/benign prostatic hyperplasia.

METHODS

Prostate volume was measured by transrectal ultrasonography in 576 Japanese men. The association between prostate volume and routine clinical inflammatory markers (C-reactive protein level, white blood cell count, or the differential white cell count [neutrophils, lymphocytes, basophils, eosinophils, and monocytes]) were analyzed. Contributors to prostate volume were identified in univariate and multivariable linear regression models.

RESULTS

Prostate volume was found to have a positive association with serum prostate-specific antigen level (P < 0.001), white blood cell count (P = 0.027) and absolute neutrophil count (P = 0.010). In univariate linear regression models, a large prostate volume was associated with older age, higher prostate-specific antigen, and higher white blood cell and neutrophil counts. A multivariable model adjusted for age, prostate-specific antigen, and C-reactive protein showed that the white blood cell count and the neutrophil count were independently associated with prostate volume. An increased white blood cell count was also associated with higher total International Prostatic Symptom Scores (P < 0.001).

CONCLUSIONS

White blood cell count seems to be associated with the degree of prostate enlargement and lower urinary tract symptoms. Chronic low-grade systemic inflammation might be involved in the etiology of benign prostatic hyperplasia.

Tadalafil for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia: pathophysiology and mechanism(s) of action

BACKGROUND

The PDE5 inhibitor tadalafil is investigation for the treatment of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). Several clinical studies of tadalafil and other PDE5 inhibitors have reported significant symptom reduction but limited urinary flow rate improvement. This manuscript reviews the published literature describing the pathophysiology of male LUTS, with an emphasis on mechanisms that may be modulated or improved by phosphodiesterase type 5 (PDE5) inhibition.

METHODS

Literature (through March 2010) was obtained via Medline searches and from the individual reviewers files. Articles were selected for review based on describing in vitro, preclinical, or clinical studies of pathological processes contributing to LUTS, or possible effects of PDE5 inhibition in the lower urinary tract.

RESULTS

Major mechanisms contributing to LUTS include: reduced nitric oxide/cyclic guanosine monophosphate signaling; increased RhoA kinase pathway activity; autonomic overactivity; increased bladder afferent activity; and pelvic ischemia. Tadalafil and other PDE5 inhibitors have demonstrated beneficial effects on smooth muscle relaxation, smooth muscle and endothelial cell proliferation, nerve activity, and tissue perfusion that may impact LUTS in men.

CONCLUSIONS

The pathophysiology of male LUTS is complex and not completely understood. LUTS may occur independently of BPH or secondary to BPH but in both cases involve obstructive or irritative mechanisms with substantial pathophysiological overlap. While the precise mechanism remains unclear, inhibition of PDE5 seems to have an effect on several pathways that may impact LUTS.

Prostate specific antigen reduction following statin therapy: Mechanism of action and review of the literature

Prostate specific antigen (PSA) is a serine protease that is exclusively produced in the prostate, and its detection is the only laboratory test available for screening men for prostate cancer (PC). The interpretation of the assay is difficult since it is specific for prostate tissue and cellular growth, but not for PC. Pharmacologic therapy for hyperlipidemia, such as statins, may influence prostate cellular growth and subsequently PSA levels in patients. Dysregulated cellular growth in the prostate is mediated by inhibiting the rate-limiting pathway step in cholesterol synthesis, thereby decreasing isoprenylate intermediates, decreasing cholesterol rich cellular membrane domains, and down-regulating androgen and estrogen receptors. Statins, with variable efficacy, have been previously shown to inhibit cellular inflammation, angiogenesis, proliferation, migration/adhesion, and invasion, while promoting apoptosis in prostate cells by inhibiting the conversion of HMG-CoA to mevalonate. An individual statin's molecular structure, need for enzymatic conversion, bioavailability, and peripheral tissue concentration may partially account for differing properties. By inhibiting prostatic cellular growth and promoting apoptosis, statins may subsequently decrease PSA levels, an effect recently observed in cohorts. There is scientific and clinical evidence supporting the observations that statins are associated with an overall reduction in serum PSA in men, when used for greater than 6 months, and especially when used for greater than 2 years.

The effects of lovastatin on conventional medical treatment of lower urinary tract symptoms with finasteride

OBJECTIVE

To explore whether or not statins have any impact on the progression of components of benign prostatic hyperplasia (lower urinary tract symptoms severity, prostate volume and serum prostate specific antigen (PSA) when combined with other agents inhibiting growth of prostate cells.

MATERIALS AND METHODS

This was a preliminary, clinical study. Eligible patients were aged > 50 yrs, with International Prostate Symptom Score (IPSS) between 9 and 19, total prostate volume (TPV) >40 mL, and serum PSA > 1.5 ng/mL. Patients were divided in two groups: those with and those without lipidemia. After selection, eligible BPH patients with lipidemia (n = 18) were prescribed lovastatin 80 mg daily and finasteride 5 mg daily, while eligible patients without lipidemia (n = 15) were prescribed only finasteride 5 mg daily. IPSS, TPV and serum PSA were evaluated at end point (4 months).

RESULTS

There was no difference between the two groups on the primary end point of mean change from baseline in IPSS (p = 0.69), TPV (p = 0.90) and PSA (p = 0.16) after 4 months of treatment.

CONCLUSIONS

Short-term lovastatin treatment does not seem to have any effect on IPSS, TPV and PSA in men with prostatic enlargement due to presumed BPH.

Atherosclerosis as a risk factor for benign prostatic hyperplasia

OBJECTIVES

To evaluate the relationship between clinical benign prostatic hyperplasia (BPH) and atherosclerosis, using colour Doppler ultrasonography (CDUS) and symptom scores.

PATIENTS, SUBJECTS AND METHODS

CDUS was used to evaluate prostatic vascularity in four groups of men, comprising young healthy subjects, patients presenting with coronary artery disease (CAD), diabetes mellitus, or peripheral arterial occlusive disease (PAOD). Resistive index (RI) measurements and computer-assisted quantification of colour pixel density (CPD) were used to objectively evaluate perfusion. The International Prostate Symptom Score (IPSS) and the International Index of Erectile Function were used to quantify symptoms.

RESULTS

In diabetic patients and men with PAOD, perfusion of the transition zone (TZ) of the prostate was significantly lower (P < 0.001) and the RI of the TZ was significantly higher (P < 0.001) than in healthy controls and men with CAD. In diabetics and men with PAOD, the mean prostate volume was greater than in healthy controls and men with CAD. The IPSS in patients with vascular damage (diabetes, PAOD) was significantly worse than in the control group.

CONCLUSIONS

The significantly lower CPD and higher RI values of the TZ in patients with vascular disease than in healthy subjects support the hypothesis that an age-related impairment of blood supply to the prostate has a key role in the development of BPH.

Vascular resistance in the prostate evaluated by colour Doppler ultrasonography: is benign prostatic hyperplasia a vascular disease?

OBJECTIVE

To evaluate prostatic vascular resistance by measuring the resistive index (RI), and flow velocity using colour Doppler ultrasonography (CDUS), in normal prostates and in patients with benign prostatic hyperplasia (BPH) or prostate cancer, as BPH is considered to be a result of urogenital ageing and studies suggest that hyperplasia in the stromal and glandular compartments might be induced by stromal growth secondary to hypoxia, which in turn results from abnormal blood flow patterns.

PATIENTS, SUBJECTS AND METHODS

Ninety-two men (22 with normal prostates, 45 with BPH and 25 with prostate cancer; mean age 56 years) were prospectively evaluated by CDUS. The RI values for the peripheral, central and transition zones were assessed by one investigator. The diagnosis of BPH and prostate cancer was established from histological findings.

RESULTS

The mean (sd) RI in the transition zone was significantly higher only in patients with BPH, at 0.77 (0.05), vs 0.65 (0.05) in the other two groups. In the peripheral and central zones there was no significant difference in the RI among the three groups. Arterial CDUS flow velocity was increased in the transition zone of patients with BPH, but not in the peripheral and central zones.

CONCLUSIONS

The present results support the hypothesis that an age-related impairment of blood supply to the lower urinary tract might have a role in the development of BPH. Although prostate cancer cannot be excluded by measuring RI, high RI values (>0.75) in the transition zone are indicative of BPH.

An immunohistochemical assessment of hypoxia in prostate carcinoma using pimonidazole: implications for radioresistance

PURPOSE

To investigate the presence of hypoxia in human prostate carcinoma by using pimonidazole immunohistochemical labeling in radical prostatectomy specimens.

METHODS AND MATERIALS

Forty-three patients (median age, 69 years; range, 49-83 years) with localized prostate adenocarcinoma received 0.5 gm/m2 i.v. pimonidazole 16-24 h before radical prostatectomy. Hypoxia was detected with a monoclonal antibody directed against pimonidazole and scored in formalin-fixed, paraffin-embedded sections. Median and maximal vessel counts were measured with CD34.

RESULTS

Thirty-seven patients completed the study. Pimonidazole binding was present in prostate carcinomas in 34 of 37 patients (92%) and in benign prostatic hyperplasia in 35 of 37 patients (95%). A positive correlation of 3+ pimonidazole binding with Gleason score was demonstrated (Spearman's rank, p = 0.044). Vascularity scores did not correlate with hypoxic status or clinical prognostic parameters.

CONCLUSION

Prostate carcinoma and benign prostatic hyperplasia have significant areas of hypoxia; greater hypoxia scores are seen with more aggressive prostate cancer. It is postulated that a hypoxic microenvironment within the prostate might be responsible for the promotion of secondary genetic alterations and angiogenic stimulation, leading to malignant progression, a more aggressive cell phenotype, and greater radioresistance. Modification of radiation regimens to specifically target hypoxia might improve local tumor control.

Vascular damage as a risk factor for benign prostatic hyperplasia and erectile dysfunction

OBJECTIVE

To assess benign prostatic hyperplasia (BPH) and erectile dysfunction (ED), both considered to be associated with urogenital ageing, in ageing men in a cross-sectional population study, comparing them with healthy controls by using symptom scores and contrast-enhanced colour Doppler ultrasonography (CDUS).

PATIENTS, SUBJECTS AND METHODS

Transrectal CDUS and quantitative measurement of colour pixel intensity (CPI) are excellent minimally invasive techniques for assessing normal and pathological blood flow. CDUS was performed using the microbubble-based ultrasound enhancer for evaluating prostate, bladder neck and corpus cavernosum vascularity in young healthy men, men with BPH, and men with severe vascular damage (diabetes mellitus type 2). Resistive index measurements and computer-assisted quantification of CPI were used to objectively evaluate perfusion. The International Prostate Symptom Score (IPSS) and the International Index of Erectile Function (IIEF) were applied to quantify the symptoms.

RESULTS

In patients with BPH, perfusion of the transition zone (TZ) of the prostate was significantly lower and the resistive index of the TZ significantly higher (both P < 0.001) than in healthy controls. The perfusion patterns of men with BPH and those who also had severe vascular damage (diabetes mellitus type 2) showed that vascularity in the latter group was lower in the prostatic TZ and the corpora cavernosa. In patients with BPH the IPSS, quality-of-life and IIEF scores were significantly worse than in the control group. Men with concomitant atherosclerosis had even worse symptom scores.

CONCLUSION

These results strongly support the hypothesis that age-related impairment of blood supply to the lower urinary tract is important in the development of BPH and ED. Vascular damage may cause chronic ischaemia and thus be a contributing factor in the pathogenesis of BPH and ED.

Administration of extract of mushroom Phellinus linteus induces prostate enlargement with increase in stromal component in experimentally developed rat model of benign prostatic hyperplasia

OBJECTIVES

To clarify the effect of the mushroom extract Phellinus linteus on noncancerous prostate cells using an experimentally developed rat benign prostatic hyperplasia model. A growing number of people take some natural herbal extracts for maintenance of their health. Among them, the extracts of certain mushrooms are believed to have a marked tumoricidal effect but low toxicity for normal tissues, and they are being drunk widely in Japan and Korea. However, until now, their effect on noncancerous benign prostate growth has not been examined.

METHODS

The mushroom extract was administered daily for 5 weeks to experimentally developed benign prostatic hyperplasia rats. Prostate organ weight, histologic composition, and gene expression levels of sex hormone receptors, transforming growth factor-beta, vascular endothelial growth factor, and endothelial nitric oxide synthase were examined.

RESULTS

Prostate weight increased significantly by 37% owing to treatment with the mushroom extract (P < 0.05). In particular, the stromal component of the prostate increased significantly by 80% (P < 0.05). A suppression of transforming growth factor-beta1 expression by 56% was observed with the mushroom extract treatment (P < 0.05).

CONCLUSIONS

We found that the mushroom extract enlarged the prostate. The effect was suggested to be on the prostate stroma, which may be involved in transforming growth factor-beta1 regulation. Administration of mushroom extract should be considered carefully by those with an enlarged prostate.

Vascular damage induced by type 2 diabetes mellitus as a risk factor for benign prostatic hyperplasia

AIMS/HYPOTHESIS

The aim of this study was to evaluate the relationship between benign prostatic hyperplasia (BPH) and arteriosclerosis shown in a model of type 2 diabetes in a trans-sectional population study using contrast-enhanced colour Doppler ultrasound for exact assessment of prostatic blood flow.

METHODS

Contrast-enhanced transrectal colour Doppler ultrasound was performed using a microbubble-based ultrasound enhancer SonoVue for evaluating prostate vascularity (transitional zone [TZ] and peripheral zone [PZ]) in diabetic BPH patients, non-diabetic BPH patients and healthy subjects. Computer-assisted quantification of colour pixel intensity (CPI) was used to objectively evaluate the prostate vascularity. Resistive index measurements were obtained in the TZ and the PZ. Findings were compared between these three groups.

RESULTS

TZ-CPI was significantly lower in diabetic patients than in non-diabetic BPH men (p=0.001), whereas the CPI of the PZ showed no difference between these two groups (p=0.978). TZ-CPI of patients with diabetic and non-diabetic BPH were significantly lower than in controls (p<0.001), but no difference was found between diabetic and healthy patients in the PZ (p=0.022) and borderline significance was seen when comparing patients of the BPH group with the control patients (p=0.019). Resistive index values of the TZ in diabetic patients showed significantly higher values (p<0.001) than the BPH and control groups.

CONCLUSIONS/INTERPRETATION

The significantly lower CPI and higher resistive index values of the TZ in diabetic patients compared with patients with non-diabetic BPH and healthy subjects indicate considerable vascular damage in the TZ of these patients. Diabetic vascular damage may cause hypoxia and may contribute to the pathogenesis of BPH.

Increased growth factor production in a human prostatic stromal cell culture model caused by hypoxia

BACKGROUND

Local hypoxia may be one of the triggers of embryonic reawakening of the stroma and subsequent hyperplastic growth in the prostate. Using a cell culture model of human prostatic stromal cells, we investigated the effects of hypoxia on activation of hypoxia-inducible factor 1 (HIF 1) and on the production of growth factors.

METHODS

Primary prostatic stromal cells were grown in normal and hypoxic (1% O(2)) atmosphere. Activation of HIF 1 was evaluated after different time intervals by Western blot. Induced secretion of growth factors VEGF, FGF-7, TGF-beta, IL 8, and FGF-2 were analyzed by ELISA. To confirm the in vitro findings we also performed immunohistochemistry of HIF 1alpha as well as pro-collagen I, collagens I, III, and IV in the benign tissue of radical prostatectomy specimens.

RESULTS

HIF 1 is activated in a time-dependent manner, already starting 1 hr after exposure of stromal cells to hypoxic conditions. Secretion of VEGF, FGF-7, TGF-beta, FGF-2, and IL 8 is increased under hypoxic in vitro conditions in comparison to normoxia. Levels of TGF-beta, VEGF, and IL 8 were rapidly and statistically significantly increased in the supernatant of hypoxic cells. Consistent with the in vitro findings, immunohistochemistry of HIF 1alpha in (benign prostatic hyperplasia) BPH tissue revealed strong HIF 1alpha nuclear staining in hyperplastic areas. No difference was observed in the collagen pattern between hyperplastic and normal prostate tissue.

CONCLUSIONS

Prostatic stromal cells respond to hypoxia by upregulation of secretion of several growth factors suggesting that hypoxia can trigger prostatic growth. Therefore, hypoxia might be a key factor contributing to the pathogenesis of BPH.