Possible mechanism of benign prostatic hyperplasia induced by androgen-estrogen ratios in castrated rats

Clinicopathological and immunohistochemical evaluation of lonidamine-entrapped lipid-polymer hybrid nanoparticles in treatment of benign prostatic hyperplasia: An experimental rat model

Benign prostatic hyperplasia (BPH) is a progressive proliferative disease, the incidence of which is constantly increasing due to aging of population. In this research, a hexokinase-II enzyme inhibiting agent, lonidamine - the use of which is limited in BPH treatment due to high hepatic toxicity observed after three months of treatment - was selected as an active agent, based on its mechanism of action in treating BPH. The aim of this study was to evaluate in vivo therapeutic efficacy and hepatic toxicity of lipid-polymer hybrid nanoparticles of lonidamine in a rat BPH model created in rat prostates. After local injections of hybrid nanoparticles of lonidamine were administered to the rat prostates, hyperplasic structures of prostates were evaluated in terms of prostatic index values, immunohistochemical evaluations, and histopathological findings. Liver blood enzyme values were also determined to specify hepatic toxicity. Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) reaction and histopathological methods to determine intravital degenerative destruction in liver. Through this study, lonidamine-loaded hybrid nanoparticles were found to reduce the hepatic toxicity and increase therapeutic efficiency of lonidamine. Therefore, lonidamine-entrapped hybrid nanoparticles may provide a promising, and very safe, drug delivery strategy in the treatment of BPH.

Simultaneous quantification of oestrogens and androgens in the serum of patients with benign prostatic hyperplasia by liquid chromatography-Tandem mass spectrometry

Benign prostate hyperplasia (BPH) is a common disease in elderly men. It has been found that the occurrence of BPH was closely related to dysregulated steroid hormones. Here, a rapid, sensitive, accurate and specific method for the quantitative profiling of five androgens in man serum was developed and validated by the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using this method, dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T), androsterone (A), dihydrotestosterone (DHT), oestrone (E1) and oestradiol (E2) were quantified in serum from man with and without BPH. BPH patients were characterised by the decreases in DHEA, A4 and T as well as increases in DHT, E2 and E1 in serum. Meanwhile, DHEA and DHT in serum were screened as sensitive biomarkers of BPH patients. This study will provide a new perspective of dysregulated steroid hormones for the diagnosis and prevention of BPH.

Meta-Analysis of steroid-converting enzymes and related receptors in prostate cancer suggesting novel combined therapies

Androgen receptor (AR) signaling is essential for prostate cancer (PC) progression and treatment. Experiments have demonstrated that the intratumoral androgen levels are not affected by circulating androgen levels, but rather modulated by local steroid-converting enzyme activities. The expression modulation status of human steroid-converting enzymes and nuclear receptors are of great promise to identify novel therapeutic targets. Meta-analysis was performed with 9 cohorts (1093 specimens) from Gene Expression Omnibus, 16 cohorts (933 specimens) from Oncomine and the TCGA cohort (550 specimens). We found significant up regulation of 5α-reductase type 1 and type 3 in both primary and metastatic PC, together with the down regulation of AKR1C2 in primary PC, contributing to the high intratumoral DHT levels. The expression of AR in metastatic PC was up regulated, indicating the importance of AR signaling in the progression of this cancer. The down regulations of HSD11B1 and NR3C1 in primary and metastatic PC may diminish the anti-inflammation and anti-proliferation effects of glucocorticoids signaling. Furthermore, the decrease of progesterone receptor (PGR) expression in primary and metastatic PC was also observed, relieving the suppression effect of PGR on PC proliferation. The clinical evidences of the remarkable expression modulation of steroid-converting enzymes and receptors in PC may indicate novel combined treatment against this highly incident cancer.

Role of sex hormone on morphological and histological changes in benign prostatic hypertrophy rats

BACKGROUND

The prostate, the key secondary male reproductive organ, serves an important function of alkalizing seminal fluid and protecting genetic information in the acidity of the vaginal tract. As males age, the most common urologic condition manifests as an enlargement of the prostate known as benign prostatic hypertrophy (BPH). The purpose of this study is to examine the relationship between hormonal regulation and the morphological changes in BPH. Furthermore, we examine whether the ion-transport pump, H-K-ATPase (HKA), mediates such hormonal regulation. The experiments were designed to test the effects of the primary male androgen, testosterone propionate (TP), as well as the female hormone, estradiol (E2).

METHODS

The rats were divided into three groups; control group, TP group, and TP+E2 group. Both the TP and the E2 were diluted in vegetable oil and covered to eliminate light exposure. A subcutaneous injection of TP at 3 mg/mL was administered to induce BPH in each rat. After 6 weeks of TP-induced BPH, we divided these rats into two groups. In one group of BPH rats, we injected 60 µg of E2, and in another group of BPH rats, we injected 120 µg of E2 subcutaneously. The rats were sacrificed under anesthesia, and the prostate specimens were dissected. The rat's body weight and the prostate tissue weight were measured as the organ quotient.

RESULTS

The data indicate significant hypertrophy of the luminal cells in rats with 3 mg TP compared to the control (524.542 ± 4.637 vs. 350.583 ± 1.996, P-value < 0.005). Whereas, the group with 60 µg E2 on TP-induced BPH showed significant inhibitory effects compared to TP-induced BPH (385.571 ± 7.265 vs. 524.542 ± 4.637, P-value < 0.005). The experimental group with 120 µg E2 on TP-induced BPH also showed significant inhibitory effects compared to TP-induced BPH (465.857 ± 8.259 vs. 524.542 ± 4.637, P-value < 0.005). The inhibitory effects of the 60 µg E2 group were more significant than the inhibitory effects of the 120 µg E2 group (385.571 ± 7.265 vs. 465.857 ± 8.259, P-value < 0.005), suggesting the importance of maintaining a proper E2:TP ratio. Western blot analysis shows up-regulation of specific bands for HKA alpha subunit at ~97 kDa for TP-induced BPH and down-regulation of HKA in the TP+E2 treatment groups.

CONCLUSIONS

The results show that TP induces benign prostate hypertrophy. Whereas, E2 is shown to inhibit BPH; the effect of E2 inhibition on BPH requires the optimal ratio between E2 and TP. If such a ratio is not reached, then BPH inhibition will not occur or will be less effective by E2. Both the induction and inhibition of hypertrophic cells suggest that the prostate is under hormonal regulation. The proper E2:TP ratio plays a crucial role in the pathogenesis of BPH. The ratio of E2:TP may lead to new approaches to preventing and treating BPH disease in the future.

Estrogen and estrogen receptor alpha promotes malignancy and osteoblastic tumorigenesis in prostate cancer

The role of estrogen signaling in regulating prostate tumorigenesis is relatively underexplored. Although, an increasing body of evidence has linked estrogen receptor beta (ERβ) to prostate cancer, the function of estrogen receptor alpha (ERα) in prostate cancer is not very well studied. We have discovered a novel role of ERα in the pathogenesis of prostate tumors. Here, we show that prostate cancer cells express ERα and estrogen induces oncogenic properties in prostate cancer cells through ERα. Importantly, ERα knockdown in the human prostate cancer PacMetUT1 cells as well as pharmacological inhibition of ERα with ICI 182,780 inhibited osteoblastic lesion formation and lung metastasis in vivo. Co-culture of pre-osteoblasts with cancer cells showed a significant induction of osteogenic markers in the pre-osteoblasts, which was attenuated by knockdown of ERα in cancer cells suggesting that estrogen/ERα signaling promotes crosstalk between cancer and osteoblastic progenitors to stimulate osteoblastic tumorigenesis. These results suggest that ERα expression in prostate cancer cells is essential for osteoblastic lesion formation and lung metastasis. Thus, inhibition of ERα signaling in prostate cancer cells may be a novel therapeutic strategy to inhibit the osteoblastic lesion development as well as lung metastasis in patients with advanced prostate cancer.

Comparative effects of Yi Jin Jing versus Tai Chi exercise training on benign prostatic hyperplasia-related outcomes in older adults: study protocol for a randomized controlled trial

BACKGROUND

Benign prostatic hyperplasia (BPH) and its associated lower urinary tract symptoms (LUTS) occur very commonly in older men. BPH and LUTS cause substantial physical and psychological impairment that could seriously affect the quality of late life and greatly cost the health-care systems. Current surgical and pharmacological therapies are expensive, may not effectively improve prostate function and health but cause adverse effects. There is an urgent need to find new and effective non-pharmacological preventions and treatments. Yi Jin Jing and Tai Chi are two common traditional Chinese mind-body exercises with different movements and techniques, but both emphasize regulating functional homeostasis and keeping whole body harmony. Yi Jin Jing and Tai Chi have not been studied much for potentially use in the treatment of BPH-related problems. The primary purpose of this protocol is to assess the effectiveness of Yi Jin Jing versus Tai Chi on the monographic and functional changes of prostate in older men.

METHODS/DESIGN

A prospective single-center randomized controlled trial will be conducted. A total of 150 old men (60-70 years old) will be recruited from the urban tertiary of Shanghai, China. Of these, 50 eligible participants will be randomly assigned to a control group and two intervention groups with either Yi Jin Jing or Tai Chi exercise training. They will undergo 30 minutes for each exercise for five times a week for 6 months. The primary outcomes are changes of signs and symptoms in BPH and lower urinary tract from baseline to post-intervention. The main secondary outcomes are exercise-induced effects on the circulating levels of estrogen and androgen. All the outcome measures will be assessed at baseline, immediately after the 6-month intervention, and at the 3-month post-intervention follow-up.

DISCUSSION

This proposed study will be the first comparative randomized clinical trial to evaluate the effectiveness of Yi Jin Jing versus Tai Chi exercise on prostate health among older adults. The results will provide an evidence-based recommendation for Chinese older men on the use of Yi Jin Jing and Tai Chi training to promote prostatic function and health. Potential mechanisms for the regulatory effect of the two exercises elucidated by multiple outcomes are also explored. A clarification of the effects and mechanisms may provide information for the development of new strategies in the prevention and treatment of BPH-related conditions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: ChiCTR-IOR-16007698 . This trial was registered on 4 January 2016.

Changes in mitotic reorientation and Wnt/AR signaling in rat prostate epithelial cells exposed to subchronic testosterone

The aim of the present study was to investigate the changes in mitotic reorientation and relative differential gene expression in rat prostate epithelial cells following long-term exposure to testosterone propionate (TP). Sprague-Dawley rats were randomly divided into two groups as follows: TP group, which received 3.7 mg/kg/day TP for 30 days (n=10); and control group, in which rats were injected with olive oil (n=10). Microscopic analysis of the prostate tissue was performed by immunohistochemical analysis and hematoxylin and eosin staining. Differential gene expression analysis was performed via gene microarray, and a total of five genes (Dkk3, Ran, Fas, Tgm4 and Wnt2) were selected and their expression levels were verified using reverse transcription-polymerase chain reaction. For rats treated with TP, mitosis was significantly reoriented, becoming parallel to the basement membrane. By contrast, in the control group cells mitotic orientation remained perpendicular to the basement membrane. Genes such as Ran and Tgm4 in the androgen receptor (AR) signaling pathway and Wnt2 in the Wnt signaling pathway, were upregulated following treatment with TP. Conversely, the Dkk3 and Fas genes were downregulated following treatment with TP. In conclusion, mitotic orientation of prostate epithelial cells was altered following long-term administration of TP. Wnt and AR signaling pathways influenced cell proliferation and may have participated in the mitotic orientation change.