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R Buttyan

Publications and source records attributed to R Buttyan.

At least 19 recordsLinked to original sources
PubMed1999

Vascular anatomy of the rat ventral prostate.

The rat ventral prostate gland is a model tissue to study the effects of androgenic steroids on prostate cells. Recent reports suggest that the prostatic vascular system is a primary target of androgen action in this tissue. In order to better understand how the vascular system of the ventral prostate supports the tissue in an androgenically normal adult male rat we utilized a variety of microscopic imaging techniques to more fully characterize its structural anatomy and its interaction with other prostatic cell types. Vascular corrosion casts were produced from the mature ventral prostate glands of rats. These casts were analyzed by scanning electron microscopy (SEM) to describe gross and fine details of the prostate vascular anatomy. Fixed thin sections of ventral prostates were immunostained with antiFactor XIII and analyzed by light microscopy for the presence of capillary elements within the prostatic glands. Other sections were directly analyzed by transmission electron microscopy (TEM) to describe the anatomical relationship between the capillaries and the prostatic ducts and their associated glands. The rat ventral prostate is supplied with blood by branches of the inferior vesical artery which enters the apex of the tissue from the base of the urinary bladder. Visualization of the prostatic vascular network under SEM shows that this major vessel is found on the posterior-medial surface of the tissue (closest to the bladder). This surface also has numerous serpentine vessels that appear to facilitate a stable blood supply to the prostate in accommodation of urinary bladder distension. Examination of the opposing surface of the casts allowed a crude description of the structure of the prostatic ductal system with the distal tips of the ducts (containing the prostate glands) oriented towards the anterior-lateral surface of the tissue. On this surface, one can discern a series of adjacent basket-shaped vascular structures of distributing arterioles that supply a dense complex of fine capillaries to the glands. Analysis of the interface of the prostatic ductal system with its vascular elements by light microscopy and TEM shows that some capillaries lie immediately adjacent to the basement membranes of the glands while others can be found interspersed within the myofibroblast layer surrounding the ducts and glands. Veins accompany the arteries and combine with the superior vesical before entering the common iliac vein. This study gives a comprehensive and detailed view of the microvasculature of the rat ventral prostate gland. The findings here will provide the basis for future experiments to evaluate how the ventral prostate vascular system changes in response to androgenic manipulation and to other pathological conditions.

Animals↗
PubMed1999

Apoptotic conversion: evidence for exchange of genetic information between prostate cancer cells mediated by apoptosis.

Changes in the outer membrane of apoptotic cells can induce neighboring cells to become phagocytic. Using genetically marked prostate cancer cell lines, we explored the possibility that genetic information might be transferred from an apoptotic cell to a phagocytic neighbor. Neomycin-resistant LNCaP cells that overexpress bcl-2 (LNCaP(bcl-2/neo-r)) were cocultured with hygromycin-resistant LNCaP cells (LNCaP(hygr-r)). The cocultures were then transiently exposed to serum starvation to induce apoptosis of LNCaP(hygr-r) cells. Surviving cells were then coselected in medium containing both antibiotics. Whereas monocultures of LNCaP(bcl-2/neo-r) or LNCaP(hygr-r) treated this way yielded no colonies, cocultures yielded dual-antibiotic-resistant clones at a frequency of approximately 1 in 10(5). Pre-exposure to an apoptotic agent was required; cocultures not exposed to serum starvation yielded no dual-selectable colonies. Analysis of DNA extracted from a dual-resistant clone demonstrated that the restriction endonuclease pattern of the neo-r gene was unaltered when compared with the parental LNCaP(bcl-2/neo-r). However the hygr-r gene demonstrated an altered restriction endonuclease pattern in the dual-resistant derivative compared with the parental LNCaP(hygr-r) cell line. This is evidence that genetic information can be transferred from one prostate cancer cell to another through the process of apoptosis, and we term this form of genetic transfer "apoptotic conversion."

Anti-Bacterial Agents↗
PubMed1999

Sulindac derivatives inhibit growth and induce apoptosis in human prostate cancer cell lines.

We examined the activity of two metabolites of sulindac (a nonsteroidal anti-inflammatory drug), sulindac sulfide and sulindac sulfone (exisulind, Prevatec), and a novel highly potent analog of exisulind (CP248) on a series of human prostate epithelial cell lines. Marked growth inhibition was seen with the BPH-1, LNCaP, and PC3 cell lines with IC50 values of about 66 microM, 137 microM, and 64 nM for sulindac sulfide, exisulind, and CP248, respectively. DNA flow cytometry and 4',6'-diamido-2-phenylindole (DAPI) staining indicated that these three compounds also induced apoptosis in all of these cell lines. Similar growth inhibition also was seen with the PrEC normal human prostate epithelial cell line, but these cells were resistant to induction of apoptosis at concentrations up to 300 microM, 1 mM, and 750 nM of sulindac sulfide, exisulind, and CP248, respectively. Derivatives of LNCaP cells that stably overexpress bcl-2 remained sensitive to growth inhibition and induction of apoptosis by these compounds. In vitro enzyme assays indicated that despite its high potency in inhibiting growth and inducing apoptosis, CP248, like exisulind, lacked cyclooxygenase (COX-1 and COX-2) inhibitory activity even at concentrations up to 10 mM. Moreover, despite variations of COX-1 and COX-2 expression, the three benign and malignant prostate cell lines showed similar sensitivity to growth inhibition and induction of apoptosis by these three compounds. Therefore, sulindac derivatives can cause growth inhibition and induce apoptosis in human prostate cancer cells by a COX-1 and -2 independent mechanism, and this occurs irrespective of androgen sensitivity or increased expression of bcl-2. These compounds may be useful in the prevention and treatment of human prostate cancer.

Androgens↗
PubMed1999

A recombinant defective adenoviral agent expressing anti-bcl-2 ribozyme promotes apoptosis of bcl-2-expressing human prostate cancer cells.

Over-expression of bcl-2, a potent anti-apoptosis protein, is likely to be one of the genetic mechanisms through which human prostate cancer cells develop resistance to hormonal and other forms of therapy. To develop a therapeutic agent for hormone-resistant prostate cancer based on suppression of bcl-2 expression, we had previously designed and synthesized a dual-hammerhead ribozyme capable of recognizing and specifically cleaving human bcl-2 mRNA in vitro as well as in vivo. To increase the efficiency by which the anti-bcl-2 ribozyme can be delivered to target cells, we have created a recombinant replication-deficient (defective) adenoviral agent capable of expressing the anti-bcl-2 ribozyme upon infection. This viral agent effectively reduces intracellular levels of bcl-2 mRNA and protein in cultured LNCaP prostate cancer cells following standard infection procedures. Likewise, the defective adenovirus-anti-bcl-2 ribozyme induces extensive apoptosis in several androgen-sensitive (LNCaP) and androgen-insensitive (LNCaP/bcl-2 and PC-3) human prostate cancer cell lines that express differing amounts of bcl-2 protein. One androgen-insensitive prostate cancer cell line, DU-145, lacking in bcl-2 expression, was found to be completely refractory to the effects of the virus ribozyme, supporting the concept that the cytotoxic effects of the ribozyme are based solely on its effects on bcl-2 expression. Our results support further development of this adenovirus/anti-bcl-2 ribozyme for potential gene therapeutic purposes in certain forms of hormone-resistant prostate cancer where over-expression of bcl-2 proto-oncogene is indicated.

Adenoviruses, Human↗
PubMed1999

Blood-based reverse transcriptase polymerase chain reaction assays for prostatic specific antigen: long term follow-up confirms the potential utility of this assay in identifying patients more likely to have biochemical recurrence (rising PSA) following radical prostatectomy.

Reverse transcriptase polymerase chain reaction (RT-PCR) assay is a sensitive technique to detect circulating cells expressing prostate-specific antigen (PSA) in blood or bone marrow from patients with prostate cancer. When applied to prostate cancer patients at our institution, this technique identifies those patients with a greater likelihood of extra-prostatic disease. We evaluated RT-PCR PSA as a predictor of PSA recurrence and compared it with pre-operative (serum PSA, digital rectal examination, Gleason score on biopsy) and post-operative parameters (pathological findings). Three hundred nineteen men scheduled for radical prostatectomy had an enhanced RT-PCR PSA assay before surgery. The enhanced RT-PCR PSA protocol has been previously described. PSA recurrence was defined as any serum PSA value above 0.2 microgram/l. Forty-six patients had PSA recurrence. The mean follow-up was 25.4 months. Recurrence free survival was 53% for patients with positive RT-PCR PSA vs. 84% if RT-PCR PSA was negative. By using multivariate analyses, RT-PCR PSA status was not an independent predictor of PSA recurrence compared to pathological stage pT3, Gleason score on prostate specimen and serum PSA. If only pre-operative parameters were studied, serum PSA and RT-PCR PSA status were 2 independent pre-operative predictors of PSA recurrence compared with Gleason score on biopsy and digital rectal examination. Int. J. Cancer (Pred. Oncol.) 84:360-364, 1999.

Disease-Free Survival↗
PubMed1999

The detection of renal carcinoma cells in the peripheral blood with an enhanced reverse transcriptase-polymerase chain reaction assay for MN/CA9.

BACKGROUND: Using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay, the authors previously determined the expression of MN/CA9 mRNA in renal cell carcinoma (RCC) and its absence in benign renal tissue. In the current study, the utility of an enhanced RT-PCR assay in the detection of renal carcinoma cells in the peripheral blood was assessed. METHODS: An enhanced MN/CA9 RT-PCR assay was applied to peripheral blood samples from a total of 96 patients. Forty-two patients had renal tumors, including 5 with benign renal lesions, 28 with localized RCC, and 9 with metastatic RCC. Fifty-four control patients without renal tumors were similarly tested. Pathologic staging for patients with localized cancer was T1N0M0 for 5, T2N0M0 for 9, and T3N0M0 for 14 patients. RESULTS: Cells expressing MN/CA9 were detected in 1 of 54 controls (1.8%) and in 18 of 37 cancer patients (49%). Thirteen of twenty eight patients (46%) with localized RCC and 5 of 9 (56%) with metastatic disease tested positive with the assay. No patient with a benign renal tumor exhibited MN/CA9 expression. All blood test results for patients with clear cell RCC were noted to be positive. No correlation was noted between MN/CA9 results and age, gender, or tumor grade. The differences in MN/CA9 results according to T classification were not statistically significant. CONCLUSIONS: The enhanced RT-PCR assay for MN/CA9 is a highly specific technique for detecting circulating renal carcinoma cells in the peripheral blood, and it may prove useful in the diagnosis and monitoring of RCC.

Adult↗
PubMed1999

Fas antigen/CD-95 upregulation and activation during castration-induced regression of the rat ventral prostate gland.

BACKGROUND: Fas antigen/CD 95 is a 45-kDa transmembrane protein that can initiate intracellular signaling pathways, leading to apoptosis when it is clustered on the cell surface. A recent report claiming that the ventral prostate glands of lpr -/- mutant mice (lacking functional fas antigen) do not regress following castration prompted our analysis of the regressing rat ventral prostate gland for evidence that fas antigen might participate in the molecular process leading to prostate cell apoptosis after castration. METHODS: An RNase protection assay and Western blotting analysis were used to quantify fas antigen mRNA and protein expression in the regressing rat ventral prostate gland. Immunoprecipitates of fas antigen from membrane preparations made from control or castrated rat prostates were analyzed for coprecipitation of FADD and RIP proteins to assess the activation state of the fas antigen before and after castration. Finally, prostate tissues obtained from two different strains of lpr -/- mutant mice were analyzed for induced apoptosis after castration by the TUNEL staining method. RESULTS: Rat ventral prostate gland fas antigen mRNA and protein expression was upregulated approximately 3-5-fold in the 3-day castrated rat as compared to hormonally intact rats. Immunoprecipitates of fas antigen from membranes of ventral prostates from castrated rats contained significantly increased amounts of both FADD and RIP proteins when compared to those of intact or control operated rats. However, counts of TUNEL-labeled cells in the ventral prostate glands of castrated lpr -/- mice were not significantly different from those in castrated, genetically normal controls. Likewise, the morphology of apoptotic bodies formed in the prostates of castrated lpr -/- mice was indistinguishable from that in control animals. CONCLUSIONS: Fas antigen/CD-95, a protein that is involved in some forms of apoptosis, is upregulated during regression of the rat ventral prostate gland and becomes functionally "activated." However, our inability to distinguish any difference in the apoptosis rate or in the morphology of the apoptotic bodies formed in response to castration between lpr -/- mice and genetically normal controls indicates that, contrary to the prior report, functional fas protein is not required for castration-induced prostate cell apoptosis.

Animals↗
PubMed1999

Unique morphological aspects of the rat ventral prostate gland revealed by vascular corrosion casting.

BACKGROUND: There is growing interest as to the potential role of the prostatic vascular system in mediating the effects of androgenic steroids on growth control of the prostate. Here we describe the use of a vascular corrosion casting technique that enables the visual characterization of the vascular system of the rat ventral prostate and the description of some unique morphological features of the mature rat prostate gland that were never previously observed. METHODS: Anesthetized adult male Sprague-Dawley rats were vascularly perfused with a fixative solution and then with a catalyzed methacrylate-based casting solution that was allowed to polymerize in situ. Ventral prostate glands were dissected from these rats and the tissues were subsequently dissolved in a corrosive solution, leaving residual vascular casts. The casts were then examined by scanning electron microscopy for pertinent morphological features. RESULTS: Vascular corrosion casts of individual lobes of the mature rat ventral prostate revealed a complex vascular structure that entered into the prostate near the base of the bladder. The morphological correspondence of the prostatic vasculature to the previously described ductal organization of the prostate was readily apparent. Examination of the entire vascular complex (under low-power scanning electron microscopy) revealed three differing surface features of the tissue and suggested that the glandular elements of the ventral prostate were directionally oriented towards a single surface (the anterior-lateral surface). An opposing face (posterior-medial) of the tissue demonstrated some unique spiral vessels, suggesting the need for a potential stretch-compensation mechanism at the prostate surface immediately adjacent to the bladder. CONCLUSIONS: Vascular casts of the rat ventral prostate gland reveal the obvious ductal organization of the prostatic parenchyma and demonstrate that these ducts are directionally oriented so that the glands of the prostate (at the distal tips of the ducts) uniformly lie near the anterior-lateral surface of the tissue. Unusual spiral arterioles found proximal to the bladder surface suggest that the rat ventral prostate gland has acquired the means to adapt to an anatomical position adjacent to a tissue (bladder) that acutely varies in size during the micturition cycle.

Animals↗
PubMed1999

Exisulind (sulindac sulfone) suppresses growth of human prostate cancer in a nude mouse xenograft model by increasing apoptosis.

OBJECTIVES: Recent studies have shown that Exisulind, a sulfone metabolite of the nonsteroidal anti-inflammatory drug (NSAID) sulindac, has inhibitory activity in vitro with cultured human prostate cancer cells. To determine whether this effect might be pharmacologically relevant in vivo, we tested whether Exisulind therapy could suppress the growth of human prostate cancer cells in a nude mouse xenograft model. METHODS: Thirty athymic nude mice were injected subcutaneously in the flank with 1 x 10(7) LNCaP human prostate tumor cells. All mice received a control diet for 21 days. One group of mice was continued on this control diet for an additional 4 weeks, a second group was switched to a diet supplemented with 0.05% Exisulind (40% of maximal tolerated dose [MTD]), and a third group was switched to a diet supplemented with 0.1% Exisulind (80% MTD) for the additional 4 weeks. Tumor growth was measured through the 4-week test period, and subsequently tissue sections from the various groups were tested for apoptotic and dividing cells by quantified use of the TUNEL assay and a bromodeoxyuridine (BrdU) incorporation immunoassay. RESULTS: Tumors grew by 158%, 24%, and 18% for the control and 0.05% and 0.1% Exisulind groups, respectively (P = 0.02) during the 4-week test period. Immunohistochemical studies on excised tumors showed an increased number of apoptotic bodies in the treated groups versus the control group (P<0.0001) but no change in the number of BrdU positive cells. CONCLUSIONS: This is the first study to show a direct in vivo effect of an NSAID-derived drug, lacking cyclooxygenase inhibitory activity, in a xenograft model of prostate cancer. Clinical studies to evaluate the effects of Exisulind against prostate cancer in humans are warranted.

Animals↗
PubMed1999

Regulation of Apoptosis in the Prostate Gland by Androgenic Steroids.

The prostate gland requires androgenic steroids for its appropriate embryological formation and postpubertal growth and, once at adult size, remains dependent on a continuous supply of androgens for its vitality and function. A reduction of the levels of circulating androgens will rapidly induce apoptosis of the cells of the prostate, leading to extensive glandular regression. Studies of rodent models of prostate response to castration have shown that there are some remarkable changes in the gene activity of prostate epithelial cells leading up to apoptosis. There is now evidence for a critical cell signaling pathway, regulated by c-fos expression, necessary for castration-induced apoptosis, as well as evidence that this signaling initiates an abrupt and transient alteration in the synthesis of fas antigen, p53, bax and bcl-2 proteins in the androgen receptor-expressing prostate epithelial cells, the cellular compartment that appears to be the most affected by castration. However, more recent studies suggest that these castration-induced effects on the prostate epithelial cells might be, at least in part, an indirect response to a critical reduction in blood flow to the prostate gland that precedes the onset of epithelial cell apoptosis. The castration effects on blood flow to the prostate gland seem to be related to vascular degeneration associated with apoptosis of a subset of prostate endothelial cells.

Journal Article↗
PubMed1999

An elevated bax/bcl-2 ratio corresponds with the onset of prostate epithelial cell apoptosis.

The prostate gland in adult male rats is highly dependent on androgenic steroids. Castration initiates the regression of this tissue through a process involving the loss of the vast majority of cells by means of apoptosis. We studied this well characterized in vivo model of apoptosis to evaluate how the expression of two particular gene products, bcl-2 and bax, known to be important for the regulation of apoptosis were affected by castration. An RNase protection assay designed to quantify the levels of bax mRNA showed that this transcript was transiently elevated after castration, reaching a peak in expression at 3 days and declining thereafter. In contrast, bcl-2 mRNA expression was continuously elevated over a period of up to 7 days after castration. The distinct changes in the expression of the mRNAs encoding these two genes were confirmed by an in situ hybridization analysis of regressing rat ventral prostate tissues. The elevation in mRNAs were apparently restricted to the secretory epithelial cells of the gland, the cellular compartment of the tissue most affected by castration. Finally, SDS - PAGE/Western blot analysis of bax and bcl-2 protein expression in the regressing rat prostate gland with bax and bcl-2-specific antibodies showed that the changes in the bax and bcl-2 protein levels were similar and consistent to that found for the mRNAs. In summary, the expression of both bax and bcl-2 gene products are uniquely modulated during castration-induced regression of the rat ventral prostate gland. The changes we observed identify a transient but marked increase in the bax/bcl-2 expression ratio of the tissue that peaks on the second and third days after castration, coinciding with the peak periods of prostate cell apoptosis. These data support previous studies done on in vitro systems wherein it was shown that the bax/bcl-2 ratio determines the apoptotic potential of a cell.

Animals↗
PubMed1999

The microvascular architecture of the rat vagina revealed by image analysis of vascular corrosion casts.

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.

Animals↗
PubMed1999

Effects of a phytotherapeutic agent, PC-SPES, on prostate cancer: a preliminary investigation on human cell lines and patients.

OBJECTIVES: To evaluate the in vitro activity of PC-SPES, a complex phytotherapeutic agent, against prostate cancer cell lines, and to assess its activity in suppressing serum prostate specific antigen (PSA) level in patients with prostate cancer. PATIENTS AND METHODS: Four variant prostate cancer cell lines (LNCaP and an apoptosis-resistant derivative, LNCaP-bcl-2, PC3 and DU145) were exposed to three different concentrations of PC-SPES extract. Cell viability was measured at 3, 4 and 5 days of exposure using a colorimetric assay and was compared with control cultures receiving aliquots of the ethanolic extraction medium alone. Clinically, a prospective study was initiated in patients with prostate cancer who refused conventional therapy or who had failed previous cryosurgery, radiation therapy and/or hormonal therapy. The patients were treated with PC-SPES (three capsules of 320 mg/day). The serum PSA responses and side-effects were evaluated. RESULTS: All cultured prostate cancer cell lines showed a significant dose-dependent reduction in cellular viability (compared with control cultures) by exposure to 4 and 6 microL of PC-SPES extract/mL of culture medium (P<0.001). In contrast to the hormone-insensitive cell lines tested (LNCaP-bcl-2, PC-3 and DU-145), only the hormone-sensitive cell line LNCaP was affected by the lowest dose of PC-SPES extract tested (2 microL/mL medium). In the prospective clinical trial of 33 patients, with a mean (range) follow-up of 6.8 (2-24) months after initiating PC-SPES therapy, serum PSA levels were lower in 87% at 2 months and in 78% at 6 months (n=18, P=0.026). The side-effects in these patients were nipple tenderness in two (6%) and leg clots requiring heparinization in two (6%). No gynaecomastia or hot flashes were observed in this group and the treatment was well tolerated. CONCLUSIONS: In this preliminary study, an extract of the phytotherapeutic agent PC-SPES was active in suppressing the growth of cultured hormone-sensitive and -insensitive prostate cancer cell lines. In the small clinical study, PC-SPES therapy decreased serum PSA levels in most patients. However, a longer follow-up and more patients will be required to evaluate the long-term efficacy of this new phytotherapy.

Aged↗
PubMed1999

Expression of VEGF splice variants 144/145 and 205/206 in adult male tissues.

Currently, at least five different mRNA species encoding vascular endothelial growth factor-A (VEGF-A) have been characterized. These variants result from alternative splicing of the VEGF-A transcript and encode human isoforms of VEGF protein of 121, 145, 165, 189, and 206 amino acids. In the rat, a similar profile of VEGF-A splice variants has been described, each encoding one fewer amino acid than the human species. Studies of mammalian tissues have shown that these mRNA isoforms vary in abundance. Whereas VEGF 188/189, 164/165, and 120/121 (rat/human, respectively) are the predominant forms expressed in most tissues and cells examined, VEGF 144/145 and 205/206 are rare variants. Previously, VEGF 144/145 had been detected only in placental and uterine tissues and endometrial carcinoma cell lines, whereas VEGF 205/206 was detected only in fetal liver and placenta. Using an RT-PCR technique, cDNA cloning, and sequencing, we have detected and confirmed the presence of mRNA encoding VEGF 144/145 and 205/206 in both adult rat lung and penis. Therefore, these low-abundance VEGF splice variants have a more diverse expression pattern than originally predicted.

Adult↗
PubMed1999

Expression of messenger ribonucleic acid splice variants for vascular endothelial growth factor in the penis of adult rats and humans.

Erectile dysfunction is often associated with problems in vascular perfusion to the erectile components of the penis. In order to better understand the factors that control vascular formation and perfusion in the erectile tissues of the penis, we have begun to characterize the expression of vascular endothelial growth factor (VEGF) in penis tissues. VEGF is one of several polypeptides that have significant angiogenic activity in vitro and in vivo. Extensive characterization of the VEGF gene and its products has shown that several different mature mRNA transcripts exist, originating from alternative splicing of the basic VEGF transcript. These variant transcripts can encode peptides with different biological activities. Penile tissue was obtained from adult rats and from human patients undergoing penile prosthesis implantation. Analysis of the forms of VEGF transcripts was performed using a reverse transcription-polymerase chain reaction technique with primer pairs derived from the first and eighth exon of the VEGF gene. The expression levels of the various isoforms in the rat penis were then quantified using RNase protection assays. Four previously described splice variants of VEGF mRNA (VEGF 120, 144, 164, 188) were detected in rat and human penile tissues. In contrast to what is seen in the rat lung, where the most abundant form of VEGF mRNA is the 188 splice isoform, VEGF 164 is the most abundant transcript detected in the penis. Finally, sequence analysis of numerous VEGF cDNA clones obtained from the rat penis demonstrated the presence of a previously undescribed VEGF splice variant that could give rise to a protein of 110 amino acid residues (VEGF 110, GenBank accession no. AF080594). In summary, a number of VEGF mRNA isoforms are expressed in the rat and human penis, with the splice variant encoding a 164-amino acid protein present in greatest abundance. This study is a prelude to attempts to genetically manipulate VEGF expression in the penis as a therapy for erectile dysfunction.

Adult↗
PubMed1999

Can perineural invasion on prostate needle biopsy predict prostate specific antigen recurrence after radical prostatectomy?

PURPOSE: We evaluated the role of perineural invasion identified on prostate needle biopsy as a predictor of prostate specific antigen (PSA) recurrence after radical prostatectomy. MATERIALS AND METHODS: Between 1993 and 1998 radical prostatectomy was performed in 319 consecutive patients. Prostate needle biopsies were reviewed in all cases. We compared perineural invasion with other preoperative parameters, including digital rectal examination, PSA and biopsy Gleason score, for the ability to predict PSA recurrence with recurrence defined as any serum PSA level greater than 0.2 ng./ml. RESULTS: Perineural invasion was identified on 77 of 319 preoperative prostate biopsies (24%). There was PSA recurrence in 46 patients (14.4%) at a mean followup of 25.4 months (range 0.2 to 62.1). Perineural invasion statistically correlated with PSA recurrence. Kaplan-Meier analysis revealed disease-free survival rates of 24 versus 64% when perineural invasion was and was not present in the prostate biopsy (p = 0.0003, log rank 12.92). Multivariate analysis demonstrated that perineural invasion (p = 0.012) and PSA (p = 0.005) were independent preoperative predictive factors of PSA recurrence. When perineural invasion was compared with postoperative parameters, including disease stage, surgical margins and seminal vesicle invasion, it was not an independent predictor because it closely correlated with tumor stage. CONCLUSIONS: Perineural invasion on preoperative prostate needle biopsy is a strong independent predictor of PSA recurrence in patients in whom prostate cancer was treated with radical prostatectomy.

Adult↗
PubMed1999

Early effects of castration on the vascular system of the rat ventral prostate gland.

Recent studies have found that blood flow to the rat ventral prostate gland is drastically reduced at an early time after castration. These observations caused us to reevaluate the effects of castration on the various cell populations of the ventral prostate, especially those in the prostatic vascular system. Sections of ventral prostate glands obtained at different times after castration were analyzed using the TUNEL (terminal deoxynucleotide transferase-mediated dUTP nick END labeling) staining method to quantify apoptosis in different cell types. The results of this analysis showed a significant increase in TUNEL staining of prostate endothelial and (nonendothelial) stromal cells as early as 12 h postcastration that continued to 24 h after castration. In contrast, TUNEL labeling of prostate epithelial cells was not significantly increased compared with control values until 72 h after castration. The use of dual immunohistochemical staining procedures (anti-CD31 for endothelial cells or antismooth muscle actin for smooth muscle cells combined with TUNEL labeling) allowed us to confirm that the TUNEL-positive vascular cells at these early times after castration were endothelial in nature, whereas smooth muscle cells surrounding the prostate glands or portions of the afferent vascular endothelium were rarely TUNEL labeled. Electron microscopic evaluation of ventral prostate tissues at 48 h after castration provided further morphological evidence for the occurrence of apoptosis in prostate endothelial cells. Finally, the Lendrum-Fraser histochemical procedure used to identify fibrin leakage in tissues with vascular damage was applied to sections of the ventral prostate gland. This stain revealed diffuse fibrin accumulation in periglandular areas outside the capillaries and blood vessels in prostates from 24-h castrated rats, but not in prostates of sham-operated rats. Our results confirm an early effect of castration on the vascular system of the rat ventral prostate identified by increased apoptosis of endothelial cells and vascular leakiness. As these changes temporally precede the loss of epithelial cells, we propose that they may be causal rather than incidental to regression of the rat ventral prostate after castration.

Actins↗