[Expression of TGF-ß in bladder neck contracture after transurethral enucleation and resection of the prostate].

OBJECTIVE: To explore the role of transforming growth factor-ß (TGF-ß) in bladder neck contracture (BNC) after transurethral enucleation and resection of the prostate (TUERP). METHODS: This study included 300 BPH patients undergoing TUERP, aged 51－89 (69.19 ± 8.43) years, with the prostate volume of 14.4－355.8 (63.18 ± 47.63) ml and preoperative IPSS of 15－35 (26.07 ± 5.9), QOL score of 3－6 (4.43 ± 0.67), PSA content of 0.17－23.16 (2.94 ± 3.77) ug/L, urinary leukocyte increase in 50 cases, post-void residual urine volume (PVR) of 0－440 (83.53 ± 86.85) ml, and maximum urinary flow rate (Qmax) of 2.3－14.5 (7.77 ± 3.47) ml/s. During TUERP, we collected the tissues from the bladder neck at 5 and 7 o'clock as well as the BPH tissue and the tissue from the residual prostate for HE staining, immunohistochemistry (the SP method) and examination of the infiltration degree of inflammatory cells and expressions of TGF-ß1 and TGF-ß3. During the 6－24 months follow-up, 6 of the patients were confirmed with BNC based on the clinical symptoms and the results of uroflowmetry and cystoscopy, and underwent transurethral bladder neck incision and detection of the expressions of TGF-ß1 and TGF-ß3 in the bladder neck tissue with BNC. RESULTS: The bladder neck tissue without BNC was mainly composed of smooth muscle and fibrous tissues with local infiltration of inflammatory cells, and the residual prostate tissue primarily comprised fibrous and muscle tissues, mixed with a little prostatic epithelial tissue. The bladder neck tissue with BNC, compared with that harvested during the initial TUERP, exhibited significantly increased expression of TGF-ß1 (ï¼»68.20 ± 10.88ï¼½% vs ï¼»36.14 ± 7.62ï¼½%, P < 0.05), decreased expression of TGF-ß3 (ï¼»8.55 ± 4.73ï¼½% vs ï¼»20.77 ± 8.69ï¼½%, P < 0.05), and enhanced infiltration of inflammatory cells (P < 0.05). The bladder neck tissue without BNC, in comparison with the BPH tissue, showed dramatically up-regulated expressions of TGF-ß1 (ï¼»27.05 ± 8.21ï¼½% vs ï¼»1.61 ± 0.69ï¼½%, P < 0.001) and TGF-ß3 (ï¼»14.09 ± 4.19ï¼½% vs ï¼»0.32 ± 0.11ï¼½%, P < 0.001) and increased infiltration of inflammatory cells (P < 0.05). CONCLUSIONS: After TUERP, the expression of TGF-ß1 is increased, that of TGF-ß3 decreased and the infiltration of inflammatory cells enhanced in the bladder neck tissue with BNC, which suggests that BNC may be related to the expression of TGF-ß and that BNC after TUERP could be prevented by regulating the expression of TGF-ß.

RNA-binding protein Musashi2 stabilizing androgen receptor drives prostate cancer progression.

The androgen receptor (AR) pathway is critical for prostate cancer carcinogenesis and development; however, after 18-24 months of AR blocking therapy, patients invariably progress to castration-resistant prostate cancer (CRPC), which remains an urgent problem to be solved. Therefore, finding key molecules that interact with AR as novel strategies to treat prostate cancer and even CRPC is desperately needed. In the current study, we focused on the regulation of RNA-binding proteins (RBPs) associated with AR and determined that the mRNA and protein levels of AR were highly correlated with Musashi2 (MSI2) levels. MSI2 was upregulated in prostate cancer specimens and significantly correlated with advanced tumor grades. Downregulation of MSI2 in both androgen sensitive and insensitive prostate cancer cells inhibited tumor formation in vivo and decreased cell growth in vitro, which could be reversed by AR overexpression. Mechanistically, MSI2 directly bound to the 3'-untranslated region (UTR) of AR mRNA to increase its stability and, thus, enhanced its transcriptional activity. Our findings illustrate a previously unknown regulatory mechanism in prostate cancer cell proliferation regulated by the MSI2-AR axis and provide novel evidence towards a strategy against prostate cancer.

[Coiling method combined with bloodletting from the corpus cavernosum for penile incarceration with a metal ring: A case report and literature review].

OBJECTIVE: To explore the treatment of penile incarceration with a metal ring. METHODS: Based on our experience in the successful management of a case of penile incarceration with a metal ring by coiling and bloodletting from the corpus cavernosum, we reviewed the relevant literature and analyzed the indications, advantages and disadvantages of different methods for the treatment of penile incarceration with a circular foreign body. RESULTS: The clamping and cutting methods were non-invasive, fast, effective, and with few complications, which could be applied to the treatment of penile strangulation at all levels. However, clamping was not desirable enough for a hard metal ring and the cutting method took a longer time and might increase the risk of unnecessary damage to the penile skin, urethra and cavernous body. Prepuce edema decompression and the thin tube-coiling method, with the advantages of minimal invasiveness, simple operation and no need of special tools, were suitable for penile strangulation injury under level 3, but might cause penile skin injury and potential postoperative erectile dysfunction. Surgical resection, as an invasive procedure, could be applied to severe penile strangulation at level 4 or 5. CONCLUSIONS: The principle for the treatment of penile incarceration with a circular foreign body is to remove the foreign object as soon as possible and not to add secondary damage.

[Finasteride inhibits microvascular density and VEGF expression in the seminal vesicle of rats].

OBJECTIVE: To investigate the effect of finasteride on the microvascular density (MVD) and the expression of the vascular endothelial growth factor (VEGF) in the seminal vesicle of rats. METHODS: Forty male SD rats were randomly and equally divided into groups A, B, C and D, those in groups A and B fed with normal saline as the control and those in C and D with finasteride at 40 mg per kg of the body weight per day, A and C for 14 days and B and D for 28 days. Then the seminal vesicles of the animals were harvested for HE staining, measurement of MVD, determination of the expressions of CD34 and VEGF by immunohistochemistry, and observation of histomorphological changes in the seminal vesicle. RESULTS: The expressions of CD34 in groups C and D were decreased by 6.7% and 15.8% as compared with those in A and B (P<0.01), and that in group D decreased by 9.3% in comparison with that in C (P<0.01). The expression indexes of VEGF in groups C and D were decreased by 6.9% and 14.1% as compared with those in A and B (P<0.01), and that in group D decreased by 9.0% in comparison with that in C (P<0.01). CONCLUSIONS: Finasteride can inhibit the expression of VEGF in the seminal vesicle tissue of the rat and hence suppress the angiogenesis of microvessels of the seminal vesicle.

Common Stress Transcriptome Analysis Reveals Functional and Genomic Architecture Differences Between Early and Delayed Response Genes.

To identify the similarities among responses to diverse environmental stresses, we analyzed the transcriptome response of rice roots to three rhizotoxic perturbations (chromium, ferulic acid and mercury) and identified common early-transient, early-constant and delayed gene inductions. Common early response genes were mostly associated with signal transduction and hormones, and delayed response genes with lipid metabolism. Network component analysis revealed complicated interactions among common genes, the most highly connected signaling hubs being PP2C68, MPK5, LRR-RLK and NPR1. Gene architecture studies revealed different conserved promoter motifs and a different ratio of CpG island distribution between early and delayed genes. In addition, early-transient genes had more exons and a shorter first exon. IMEter was used to calculate the transcription regulation effects of introns, with greater effects for the first introns of early-transient than delayed genes. The higher Ka/Ks (non-synonymous/synonymous mutation) ratio of early-constant genes than early-transient, delayed and the genome median demonstrates the rapid evolution of early-constant genes. Our results suggest that finely tuned transcriptional control in response to environmental stress in rice depends on genomic architecture and signal intensity and duration.

[Transrectal ultrasound conductance-guided administration of traditional Chinese medicine for histological prostatitis in men with small-size BPH and LUTS after TURP].

OBJECTIVE: To investigate the effects of transrectal ultrasound conductance (TRUSC)-guided administration of traditional Chinese medicine on histological prostatitis in men with small-size BPH and low urinary tract symptoms (LUTS) after transurethral resection of the prostate (TURP). METHODS: This study included 167 BPH patients without surgical contraindications. We randomized the patients into an experimental group (n = 84) and a control group (n = 83), with no statistically significant differences between the two groups in age, prostate volume, International Prostate Symptom Score (IPSS), and quality of life (QoL) (P >0.05). The patients of the experimental group received TRUSC-guided administration of traditional Chinese medicine, qd, for 7 days before TURP, while those of the control group underwent TURP only. After treatment, we compared the results of postoperative pathological examination of the prostate tissue, the histological grade of inflammation, IPSS, and QoL scores between the two groups of patients. RESULTS: In the experimental group, there were 12 cases of non-inflammation (14.3%), 43 cases of mild inflammation (51.2%), 28 cases of moderate inflammation (33.3%), and 1 case of severe inflammation (1.2%), as compared with 8 cases of non-inflammation (9.6%), 28 cases of mild inflammation (33.7%), 45 cases of moderate inflammation (51.8%), and 2 cases of severe inflammation (2.4%) in the control group (P <0.05). Compared with the baseline, both the experimental and control groups showed significant improvement at 4 weeks after surgery in IPSS (22.20±4.14 vs 4.26±2.64 and 23.05±4.11 vs 7.02±4.15, P <0.05) and QoL scores (4.33±0.83 vs 1.25±1.64 and 4.25±0.91 vs 2.05±1.95, P <0.05). CONCLUSIONS: TRUSC-guided administration of traditional Chinese medicine can significantly alleviate histological inflammation and improve QoL in men with small-size BPH and LUTS after TURP.

Therapeutic potential of human umbilical cord blood mesenchymal stem cells on erectile function in rats with cavernous nerve injury.

OBJECTIVE: To evaluate the therapeutic potential of human umbilical cord blood mesenchymal stem cells (hUCBMSCs) on promoting erectile function in a rat model of bilateral cavernous nerve (CN) crush injury. RESULTS: Fifty male Sprague-Dawley rats were randomly assigned to sham + PBS group (n = 10), BCNI (bilateral cavernous nerve crush injury) + PBS group (n = 10), BCNI + hUCBMSCs group (n = 30). At day 28 (n = 10) post-surgery, erectile function was examined and histological specimens were harvested. Compared with BCNI + PBS group, hUCBMSC intracavernous injection treatment significantly increased the mean ratio of ICP/MAP, nNOS-positive nerve fibers in the dorsal penile nerve, smooth muscle content, and smooth muscle to collagen ratio in the corpus cavernousum. Electron microscopy revealed few CN and major pelvic ganglion (MPG) lesions in the BCNI + hUCBMSCs group. Injected hUCBMSCs were localized to the sinusoid endothelium of the penis and MPG on day 1, 3, 7, and 28 post-intracavernous injection. CONCLUSION: hUCBMSCs intracavernous injection treatment improves erectile function by inhibiting corpus cavernosum fibrosis and exerting neuroregenerative effects on cell bodies of injured nerves at MPG in a BCNI rat model.

Electrocautery-induced cavernous nerve injury in rats that mimics radical prostatectomy in humans.

OBJECTIVE: To investigate the early and delayed effects of cavernous nerve electrocautery injury (CNEI) in a rat model, with the expectation that this model could be used to test rehabilitation therapies for erectile dysfunction (ED) after radical prostatectomy (RP). MATERIALS AND METHODS: In all, 30 male Sprague-Dawley rats were randomly divided equally into two groups (15 per group). The control group received CNs exposure surgery only and the experimental group received bilateral CNEI. At 1, 4 and 16 weeks after surgery (five rats at each time point), the ratio of maximal intracavernosal pressure (ICP) to mean arterial pressure (MAP) was measured in the two groups. Neurofilament expression in the dorsal penile nerves was assessed by immunofluorescent staining and Masson's trichrome staining was used to assess the smooth muscle to collagen ratio in both groups. RESULTS: At the 1-week follow-up, the mean ICP/MAP was significantly lower in the CNEI group compared with the control group, at 9.94% vs 70.06% (P < 0.05). The mean ICP/MAP in the CNEI group was substantially increased at the 4- (35.97%) and 16-week (37.11%) follow-ups compared with the 1-week follow-up (P < 0.05). At all three follow-up time points, the CNEI group had significantly decreased neurofilament staining compared with the control group (P < 0.05). Also, neurofilament expressions in the CNEI group at both 4 and 16 weeks were significantly higher than that at 1 week (P < 0.05), but there was no difference between 4 and 16 weeks (P > 0.05). The smooth muscle to collagen ratio in the CNEI group was significantly lower than in the control group at the 4- and 16-week follow-ups (P < 0.05), and the ratio at 16 weeks was further reduced compared with that at 4 weeks (P < 0.05). CONCLUSIONS: In the CNEI rat model, we found the damaging effects of CNEI were accompanied by a decline in ICP, reduced numbers of nerve fibres in the dorsal penile nerve, and exacerbated fibrosis in the corpus cavernosum. This may provide a basis for studying potential preventative measures or treatment strategies to ameliorate ED caused by CNEI during RP.

[Transurethral seminal vesiculoscopy combined with finasteride for recurrent hematospermia].

OBJECTIVE: To evaluate the clinical effectiveness of transurethral seminal vesiculoscopy (TUSV) combined with finasteride in the treatment of recurrent hemospermia. METHODS: This study included 32 patients with recurrent hematospermia, with the disease course of 3 months to 4 years. After administration of finasteride at 5 mg/d for 2 weeks, the patients underwent TUSV for both exploration of the causes and treatment, followed by medication with finasteride at the same dose for another 2 weeks. Postoperative follow-up was conducted for observation of the outcomes and complications. RESULTS: TUSV was successfully accomplished in all the 32 cases, which revealed 16 cases of seminal vesiculitis, 10 seminal calculi, 1 seminal vesicle cyst, 2 seminal vesicle polyps, and 3 seminal vesicle abscess. The operative time was 20 to 51 (31.0 +/- 5.2) minutes. Postoperative complications included 1 case of acute epididymitis and 3 cases of breast discomfort within the first 4 weeks. No incontinence, urethral stricture, rectal injury, retrograde ejaculation, and sexual dysfunction occurred postoperatively. All the patients but 1 were followed up for 6 months to 2 years. Twenty-nine of the cases were cured, and 2 experienced recurrence. CONCLUSION: Transurethral seminal vesiculoscopy combined with finasteride is safe and effective for the treatment of recurrent hemospermia.

[Differential gene expressions in the stromal cells of the human prostate peripheral zone in males of different ages].

OBJECTIVE: To study the gene expressions in the stromal cells of the human prostate peripheral zone (PZ) in men of different ages. METHODS: We primarily cultured stromal cells from the normal prostate PZ of men aged 23 -32 (young group) and 56 -75 years (old group), profiled the gene signature of the PZ cells by cDNA microarray, and defined the differential gene expression patterns by hierarchical cluster analysis. Among the differential genes, we selected and confirmed up-regulated genes by quantitative real time PCR (Q-PCR), and identified their protein coding by Western blotting. RESULTS: There were significant differences in the gene expressions of the PZ cells between the old and young groups. Based on the fold change ratio of > or = 2 or < or = 0.5, 509 up-regulated and 188 down-regulated genes were selected in the PZ cells. A subset of significantly differential genes influencing the growth of adjacent epithelial cells were identified, including HGF, IGF2, IGFBP5 and MMP1 in the old males. CONCLUSION: Stromal cells in the prostate PZ were more active in older males in promoting the malignant progression of adjacent prostate epithelial cells, which might be due to the increased expression of extracellular paracrining mediators.

[Characterization of stromal cell cultures from the prostatic peripheral zone of men at different ages].

OBJECTIVE: To characterize age-related cellular phenotype alterations and growth rates of human prostatic stromal cell cultures from the normal prostatic peripheral zone of young donors (PZ-young) and old donors (PZ-old). METHODS: We isolated stromal cells from 10 donors of different ages, assessed the cellular phenotypes by immunocytostaining for prolyl-4-hydroxylase, alpha-smooth muscle actin (alpha-SMA) and desmin, and analysed the ultrastructure by transmission electron microscopy (TEM). The proliferation and apoptosis of the cells were determined by Cell Counting Kit-8 assay and flow cytometry, respectively. RESULTS: All the stromal cells were positive for prolyl-4-hydroxylase regardless of the donors' age, while alpha-SMA and desmin positive cells increased with their age. The positive expressions of alpha-SMA and desmin were (2.56 +/- 1.81)% and (0.89 +/- 0.93)% in PZ-young, and (38.89 +/- 11.22)% and (14.89 +/- 5.97)% in PZ-old (P < 0.01). The alpha-SMA- and/or desmin-positive stromal cells were morphologically large, flat and polygonal. Ultrastructural analysis showed that the cell cultures from PZ-old were richer in rough endoplasmic reticulum and golgi complexes. The stromal cells of PZ-old had a lower growth rate than that of PZ-young (P < 0.01), but there was no significant difference in the apoptosis rate between the two groups. CONCLUSION: Cellular phenotypes of human prostate stromal cell cultures change with the increase of age from predominantly typical fibroblasts to a mixture of fibroblasts and myofibroblasts, which might responsible for the high incidence of prostate cancer in elderly men.

[Proportion of intermediate epithelial cells and human prostate cancer].

OBJECTIVE: To study the different proportions of intermediate epithelial cells in human prostate cancer tissue and their clinical significance. METHODS: We performed immunohistochemical staining for Cytokeratin 5 (CK5) and Cytokeratin 8 (CK8) on 60 samples of human prostate cancer, determined the proportions of intermediate epithelial cells in the cancer tissue, and classified the samples into 2 types, one with a majority of intermediate epithelial cells (CaP-INT, n = 32), and the other composed mostly of luminal epithelial cells (CaP-LUM, n = 28). Then we compared the 2 types of prostate cancer in the expression of the androgen receptor (AR), age of the patient, serum t-PSA, prostate volume, Gleason score, clinical stage, androgen resistance, and incidence of distant metastasis. RESULTS: CaP-INT showed a significantly lower expression of AR ([24.42 +/- 11.41] %) and a higher incidence of distant metastasis (n = 14) than CaP-LUM ([77.21 +/- 10.22] % and n = 4) (P < 0.05). In the CaP-INT group, 6 of the 26 endocrinologically treated cases developed into androgen-independent prostate cancer (AIPC), while in the CaP-LUM group, only 1 out of 23 (P < 0.05). The former also showed remarkably higher clinical stages than the latter (P < 0.05), but no significant differences were found in age, serum t-PSA, prostate volume and Gleason score between the two groups (P > 0.05). CONCLUSION: A higher proportion of intermediate epithelial cells may lead to increased invasiveness and metastasis of human prostate cancer.

[An update of biomarkers in prostate cancer tissue].

The development of biomarkers for prostate cancer screening, detection and prognosis has greatly decreased the mortality of this disease. Recently, some new views on such biomarkers as PSMA, CK34betaE12, p63, AMACR, Pca-24, hTERT, DD3, Annexin A3 and GSTP1 methylation in prostate cancer tissue have been re-identified and investigated. Future research should focus on the combined screening of multiple biomarkers and discovery of new ones, which may possibly improve the sensitivity, specificity and accuracy of the early detection of prostate cancer.

[Assessment of Heavy Metal Pollution and Human Health Risk of Surface Waters in the City of Ningbo, China].

In order to evaluate the present situation and the potential ecological risk of heavy metal pollution in the surface waters of eastern Chinese coastal cities, the city of Ningbo was used as an example. From surface waters in Ningbo, 255 water samples were collected. The concentrations of six heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) were measured for the samples. The potential ecological risk of these heavy metals was evaluated by calculating health risk and cancer risk indices. The results indicate that, in the surface waters of Ningbo, the average concentrations of the six heavy metals were in the increasing order of Zn > Pb > Cr > Ni > Cd > Cu. Three of the heavy metal concentrations exceeded the national environmental quality standards for surface water (GB 3838-2002, grade Ⅴ), and the order of exceeding the standard:Cd > Pb > Cr. Electroplating wastewater, metal waste produced, traffic pollutant, dyes, and coatings waste were the main pollutant sources. There were some potential health risks in over 70 percent of the surface waters in Ningbo, and the surface waters of the Zhenhai and Haishu districts had the highest potential health risk. There were three major potential health risk heavy metals, and their order of increasing risk was Cd > Cr > Pb. For adults and juveniles, the average carcinogenic risk indices were 17600 and 24800 times the critical values, respectively. Moreover, over 95 percent of the risks were attributed to Cr. The potential carcinogenic risk index of commercial areas with dense population was nearly 2 times that of the city average. The results indicated that the state of heavy metal pollution in the surface waters of Ningbo was very serious, thus the government should pay more attention to this issue.

[Effects of high concentration manganese on active oxygen production and antioxidant enzyme activities in cucumber leaves under different irradiations].

Effects of high concentration manganese on active oxygen production and antioxidant enzymes in cucumber leaves under natural irradiation and 1/2 natural irradiation were studied. High concentration manganese increased the H2O2 content and O2*- producing rate of cucumber leaves (Fig.1A, B) and caused lipid peroxidation (Fig.1C). Compare to natural irradiation, 1/2 natural irradiation significantly decreased active oxygen production and lipid peroxidation (Fig.1). CAT activities in cytosols and chloroplasts were inhibited by high concentration manganese (Fig.2B), and other antioxidant enzyme activities were enhanced by high concentration manganese (Fig.2A, C-F). Especially activities of APX, DHAR and GR in chloroplasts were greatly stimulated by high concentration manganese under natural irradiation compared to 1/2 irradiation, which may play important roles in scavenging active oxygen species. Antioxidant enzymes in mitochondria showed higher activities under high concentration manganese under natural irradiation, but the differences were not significant under 1/2 natural irradiation (Fig.2A, C-F).

Comparison of Cancer Incidence between China and the USA.

OBJECTIVE: The incidence of cancer varies around the globe, especially between less-developed and developed regions. The aim of this study is to explore differences in cancer incidence between China and the USA. METHODS: Data were obtained from the GLOBOCAN 2008 database. Estimated numbers of new cancer cases in the USA were obtained from the American Cancer Society, while the numbers of cases in China, including those in urban and rural areas, were obtained from 36 cancer registries (2003-2005). Cancer incidence for major sites between China and the USA were analyzed. RESULTS: In China, lung cancer was the predominant type of cancer detected in males; in females, breast cancer was the main type of cancer. Gastrointestinal cancers, such as those of the liver, stomach, and esophagus, were more commonly seen in China than in the USA. A significant difference in the incidence of melanoma of the skin was observed between China and the USA. During comparison of differences in the age-standardized rates by world population (ASRWs) of major cancer sites between the two countries, 4 sites in males (i.e., nasopharynx, esophagus, stomach, and liver) and 6 sites in females (i.e., nasopharynx, esophagus, stomach, liver, gallbladder, and cervix uteri) showed higher cancer incidence rates in China than in the USA. CONCLUSIONS: Significant differences in cancer incidence sites were found between the two countries. Cancer may be prevented through public education and awareness. Programs to promote cancer prevention in China, especially those of the lung, breast, and gastrointestinal region, must also be implemented.

Primary stromal cells isolated from human various histological/pathological prostate have different phenotypes and tumor promotion role.

BACKGROUND: Prostate stromal cells are known to regulate epithelial growth as well as support and maintain epithelial function. However, how stromal cells regulate epithelial cells and what differences among various histological/pathological prostate stromal cells in prostate cancer progression still remain unclear. This study aimed to investigate the different phenotypes of human various histological/pathological prostate stromal cells, and their role in tumor promotion. METHODS: The different phenotypes of the human normal prostatic peripheral zonal primary stromal cells (NPPF), transitional zonal primary stromal cells (NPTF), and prostate cancer associated primary stromal cells (CAF) were examined with growth curves and Annexin V-fluorescein isothiocyanate (FITC) assay. The different effects on prostate cancer cell line C4-2B by NPPF, NPTF, and CAF were examined with MTT assay and Annexin V-FITC assay. The gene expression of different histological/pathological prostate stromal cells was profiled by microarray and hierarchical cluster analysis. RESULTS: The growth rate of NPPF, NPTF and CAF gradually increased, followed by decreasing apoptosis. In vitro stromal-C4-2B cell line co-culture models, the proliferation and apoptosis of C4-2B cell line were differently affected by human various histological/pathological prostate stromal cells. CAF showed the most powerful effect to C4-2B cell line, as opposed to a weakest effect of NPTF. Microarray and hierarchical cluster analysis showed that the differentially expressed genes of CAF and NPPF were less than NPPF and NPTF, or CAF and NPTF. This was consistent with clinical observations that prostate cancer mostly derived from the peripheral zone and does not usually occur in the transitional zone. CONCLUSION: NPPF, NPTF and CAF possess extremely different biological characteristics and gene expression, which may play an important role in genesis and development of prostate cancer.

Differences in phenotype and gene expression of prostate stromal cells from patients of varying ages and their influence on tumour formation by prostate epithelial cells.

Prostate cancer (PCa) is an age-related disease, and the stromal microenvironment plays an important role in prostatic malignant progression. However, the differences in prostate stromal cells present in young and old tissue are still obscure. We established primary cultured stromal cells from normal prostatic peripheral zone (PZ) of donors of varying ages and found that cultured stromal cells from old donors (PZ-old) were more enlarged and polygonal than those from young donors (PZ-young). Furthermore, based on immunocytochemical and ultrastructural analysis, the components of stromal cells changed from a majority of fibroblasts to a mixture of fibroblasts and myofibroblasts with increasing donor age. Using a three-dimensional in vitro culture system, we found that PZ-old stromal cells could enhance the proliferation, migration and invasion of cocultured benign BPH-1 and PC-3 cells. Using an in vivo tissue recombination system, we also found that PZ-old stromal cells are more effective than PZ-young cells in promoting tumour formation by BPH-1 cells of high passage (>100) and PC-3 cells. To probe the possible mechanism of these effects, we performed cDNA microarray analysis and profiled 509 upregulated genes and 188 downregulated genes in PZ-old cells. Among the changed genes, we found genes coding for a subset of paracrine factors that are capable of influencing adjacent epithelial cells; these include hepatocyte growth factor (HGF), fibroblast growth factor 5 (FGF5), insulin-like growth factor 2 (IGF2), insulin-like growth factor-binding protein 4 (IGFBP4), IGFBP5 and matrix metallopeptidase 1 (MMP1). Changes in the expression of these genes were further confirmed by quantitative real-time polymerase chain reaction (PCR), Western blotting and enzyme-linked immunosorbent assays. Overall, our findings indicate that stromal cells from prostate PZ of old donors are more active than similar cells from young donors in promoting the malignant process of adjacent epithelial cells. This finding hints at a new potential strategy for the prevention of PCa.