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Background: Female sexual dysfunction is a common but poorly understood human condition. One of the aspects hindering progress in this area is the lack of appropriate animal models that can be used to study the complex factors involved in this sexual health problem. Recently, attention has focused on the probable role of vascular dynamics of the genital organs and their potential for impact on female sexuality. The objective of this study was to provide a better description of the vascular anatomy of the female rat vagina and external genital organs in an attempt to better develop this as an animal model to study female sexual dysfunction. Methods: Young female (nonestrous) virgin rats were anesthetized, the abdominal aorta was cannulated, and the distal vasculature was flushed and fixed in vivo for histological studies or for subsequent infusion with Mercox resin for vascular corrosion casting. Vascular corrosion casts of the external genitalia (vagina and vulva) were studied using a scanning electron microscope (SEM). Fixed tissue specimens were also embedded and sectioned for histochemical and immunohistochemical analysis. Results: Scanning electron microscopy imaging allowed a description of the vascular and microvascular system of the nonestrous female rat genitalia. Major feeding vessels were located laterally in the muscular and serosal layers of the vagina with a complex system of interanastomosing collaterals between these large lateral trunks. The sub-epithelial region of the vaginal wall contains a dense and rich network of capillaries that perfuse the epithelium. These data were corroborated by two- dimensional histochemistry and immunostaining for endothelial and smooth muscle cells on paraffin-embedded thin sections of the female vagina and vulva. Conclusion: This study provides the first detailed three-dimensional en bloc view of the macro- and microvascular anatomy of the female rat vagina and vulva. The findings suggest an active interaction between the microvasculature and the epithelial cells of the vaginal wall. This study will provide the basic anatomic groundwork for future experiments on perturbations of the vascular system of the rat female genitalia in response to hormonal stimuli and various disease states. [ABSTRACT FROM AUTHOR]

Background: Class III beta-tubulin (betaIII-tubulin) is expressed in tissues of neuronal lineage and also in several human malignancies, including non-small-cell lung carcinoma, breast and ovarian cancer. Overexpression of betaIII-tubulin in these tumours is associated with an unfavourable outcome and resistance to taxane-based therapies. At present, betaIII-tubulin expression remains largely uncharacterised in prostate cancer.Methods: In this report, we evaluated the expression of betaIII-tubulin in 138 different human prostate tumour specimens by immunohistochemistry from patients with hormone-treated or hormone-untreated prostate cancer. betaIII-tubulin expression was also examined in various prostatic cancer cell lines including in androgen-sensitive human prostate cancer cells, LNCaP, grown in androgen-depleted medium in 2D cultures or as tumour xenografts when the host mouse was castrated.Results: Whereas moderate-to-strong betaIII-tubulin expression was detected in only 3 out of 74 (4%) hormone-naive tumour specimens obtained from patients who never received hormone therapy, 6 out of 24 tumour specimens (25%) from patients treated for 3 months with neoadjuvant hormone therapy and 24 out of 40 (60%) castration-resistant tumour specimens from chronic hormone-treated patients were found to express significant levels of betaIII-tubulin. These findings were supported by in vitro and in vivo settings.Conclusion: Our data indicate that betaIII-tubulin expression is augmented in prostate cancer by androgen ablation and that the expression of this beta-tubulin isoform is associated with the progression of prostate cancer to the castration-resistant state, a stage largely responsible for mortality from prostate cancer. [ABSTRACT FROM AUTHOR]

β-Catenin, a component of the Wnt signaling pathway, is a coactivator of human androgen receptor (hAR) transcriptional activity. Here, we show that Wnt signaling also influences androgen-mediated signaling through its ability to regulate hAR mRNA and protein in prostate cancer (PCa) cells. Three functional LEF-1/TCF binding sites lie within the promoter of the hAR gene as shown by CHIP assays that captured β-catenin-bound chromatin from Wnt-activated LNCaP cells. Chimeric reporter vectors that use the hAR gene promoter to drive luciferase expression confirmed that these LEF-1/TCF binding elements are able to confer robust upregulation of luciferase expression when stimulated by Wnt-1 or by transfection with β-catenin and that dominant-negative TCF or mutations within the dominant TCF-binding element abrogated the response. Semi-quantitative and real time RT-PCR assays confirmed that Wnt activation upregulates hAR mRNA in PCa cells. In contrast, hAR protein expression was strongly suppressed by Wnt activation. The reduction of hAR protein is consistent with evidence that Wnt signaling increased phosphorylation of Akt and its downstream target, MDM2 that promotes degradation of hAR protein through a proteasomal pathway. These data indicate that the hAR gene is a direct target of LEF-1/TCF transcriptional regulation in PCa cells but also show that the expression of the hAR protein is suppressed by a degradation pathway regulated by cross-talk of Wnt to Akt that is likely mediated by Wnt-directed degradation of the B regulatory subunit of protein phosphatase, PP2A.Oncogene (2006) 25, 3436–3444. doi:10.1038/sj.onc.1209366; published online 13 February 2006 [ABSTRACT FROM AUTHOR]

Cyclooxygenase (COX) inhibitors have suppressive effects on several types of cancer cells including prostate cancer. In this study, we considered the potential COX-inhibitory activity of a unique anti-inflammatory herbal preparation (Zyflamend; New Chapter, Inc., Brattleboro, VT) and analyzed its effects on the human prostate cancer cell line LNCaP. COX inhibitory activity of Zyflamend was determined by a spectrophotometric-based assay using purified ovine COX-1 and COX-2 enzymes. Effects of Zyflamend on LNCaP cell growth and apoptosis in vitro were assessed by cell counting, Western blot detection of poly ADP-ribose polymerase (PARP) cleavage, and measurement of caspase-3 activity in treated and control cell extracts. Western blotting techniques were conducted to determine the effects of this herbal preparation on the expression of the cell signaling proteins, p21, androgen receptor (AR), phospho-protein kinase C (pPKC)/, and phospho (p)Stat3. The phospohorylation status of several signal transduction phosphoproteins was profiled using a high-throughput phosphoprotein screening assay in treated cells and compared to controls. Zyflamend dramatically decreased COX-1 and COX-2 enzymatic activity. Elevated p21 expression coincided with attenuated cell growth following treatment of LNCaP cells with Zyflamend. PARP cleavage fragments were evident, and caspase-3 activity was upregulated over the control indicating the ability of Zyflamend to induce apoptosis of these cells. Androgen receptor expression levels declined by 40%, and decreases were observed in the active forms of Stat3 and PKC/ in Zyflamend-treated LNCaP cells. Zyflamend inhibited both COX-1 and COX-2 enzymatic activities, suppressed cell growth, and induced apoptosis in LNCaP cells. However, our data suggests that the effects are likely due to COX-independent mechanisms potentially involving enhanced expression of p21 and reduced expression of AR, pStat3, and pPKC/. [ABSTRACT FROM AUTHOR]

Since the pioneering studies of Huggins in 1941, it has been known that prostate cancer cells, like certain normal epithelial cells, can chronically depend on a critical level of androgenic stimulation for their continuous growth and survival. The entire issue of the development of resistance to androgen ablation therapy for metastatic prostate cancer is based on the fact that a portion of cells can survive without androgen stimulation. The cell mechanism of androgen independent status is unclear. For some authors, a portion of the cells present within a patient with a prostate cancer before therapy is naturally androgen independent (selection hypothesis). However, this hypothesis does not consider gene alteration during prostate cancer natural history and probably hormone-refractory prostate cancer (HRPC) is due to a multi-step and multi-event process. In this literature review, different cell pathways that lead to HRPC are described.Prostate Cancer and Prostatic Diseases (2001) 4, 204–212. [ABSTRACT FROM AUTHOR]

A correction to the article "Complex regulation of human androgen receptor expression by Wnt signaling in prostate cancer cells," that was published in the February 2006 issue is presented.