Frequent genotype changes at -308, and 488 regions of the tumor necrosis factor-alpha (TNF-alpha) gene in patients with prostate cancer

PURPOSE

Tumor necrosis factor-alpha (TNF-alpha) is involved in oncogenesis of several cancers. The purpose of this study was to investigate whether genotype changes of TNF-alpha promoter regions (-238, -308) and at the 488 region are associated with human prostate cancer.

MATERIALS AND METHODS

The DNA from 73 cases of human prostate cancer was analyzed by allele-specific polymerase chain reaction to characterize the genotype changes of three regions of the TNF-alpha gene in prostate cancer patients. We also determined the genotype frequency in these patients. The relative risk of variant genotype was calculated by comparing with our previous data from healthy controls.

RESULTS

Genetic changes were detected in 15.1% (11/73) of prostate cancer samples at 488 region of TNF-alpha. Seventy-three percent (53/73) of the patients showed genotype GA at -308 region of TNF-alpha. Genotype GA at 488 region in TNF-alpha was observed in 73% (53/73) of the cancer and 71% (52/73) of the normal tissue. The relative risks of incidence for prostate cancer was 14-fold higher in people with genotype GA at -308 region of TNF-alpha. The relative incidence for prostate cancer was a 17-fold higher in-patient with genotype GA at 488 region of TNF-alpha. Genotype GA at -308 of TNF-alpha was related to higher clinical tumor stage of prostate cancer than genotype G (p <0.05).

CONCLUSIONS

The present study demonstrates, for the first time, that the genotype changes in -308 and 488 regions of TNF-alpha are associated with prostate cancer.

Deletion of Y-chromosome specific genes in human prostate cancer

PURPOSE

The present study is based on the hypothesis that deletion of Y-chromosome-specific genes is associated with prostate cancer. To test this hypothesis, we analyzed the deletion of six Y-chromosome-specific genes in prostate cancer samples.

MATERIALS AND METHODS

Fifty human prostate cancer specimens were processed for microdissection of pure epithelial cells. DNA was extracted from these cells and amplified using PCR and analyzed for loss of six different Y-chromosome-specific genes (SRY, ZFY, BPY1, SMCY, RBM1 and BPY2). We used D8S262 primer (chromosome 8p23) for internal control to assess the quality and loading of DNA for each sample.

RESULTS

Deletion was observed in most of the prostate cancer specimens with at least one Y-chromosome-specific gene. The loss of SRY gene (Yp11.32) was shown in 38% of cases whereas the other genes show 18% loss in ZFY (Yp11.31), 14% in BPY1 (Yq11.2), 52% in SMCY (Yq11.22), 32% in RBM1 (Yq11.23) and 42% in BPY2 (Yq12.1). The loss of most genes analyzed is seen more frequent in advanced stages and grades of prostate cancer.

CONCLUSION

There was a significant loss of Y-chromosome-specific genes in prostate cancer. The loss of SRY and BPY2 genes was more frequent in higher stages and grades of prostate cancer. This is the first report to demonstrate that the loss of Y-chromosome-specific genes is associated with prostate cancer, suggesting their role in pathogenesis of this disease.

Spondyloepiphyseal dysplasia congenita associated with conductive hearing loss

Spondyloepiphyseal dysplasia is a disorder characterized by abnormalities of growth. Previous studies of this disorder have identified a significant incidence of associated hearing loss. Hearing loss has been reported to occur in 25 to 30% of affected patients. To date, all reports of associated hearing loss have indicated the presence of a sensorineural component. In this article, we report the case of a child who was diagnosed with spondyloepiphyseal dysplasia congenita and who was found to have a significant conductive hearing loss with a Carhart's notch, indicating the likely presence of stapes footplate fixation. We also review the diagnosis of this condition and the literature associated with hearing loss as it occurs with this disorder.

Frequent genotype changes at -308 of the human tumor necrosis factor-alpha promoter region in human uterine endometrial cancer

This study was designed to test the hypothesis that genotypic changes of tumor necrosis factor alpha (TNF-alpha) promoter region are associated with endometrial cancer. TNF-alpha gene encodes a cytokine involved in angiogenesis and oncogenesis of several cancers. Some uncommon alleles are reported to be associated with increased production of TNF-alpha and the onset of various cancers. Studies of such alleles are lacking in endometrial cancer. In this study, we examined the genetic changes at the polymorphic 3 loci of TNF-alpha promoter regions (-238, -308 and 488) in 41 Japanese patients with uterine endometrial carcinomas (UEC). Nine of 41 UEC samples (22%) had genotype changes from GA to A at -308 promoter region of the TNF-alpha gene. There were no genotype changes at -238 and 488 regions of TNF-alpha in UEC samples. The results of our study demonstrate for the first time that genotype changes from GA to A in UEC patients. We conclude that the genotype changes at -308 promoter region of TNF-alpha may play an essential role in the malignant transformation of endometrial cells.

The expansion of the CAG repeat in exon 1 of the human androgen receptor gene is associated with uterine endometrial carcinoma

Uterine endometrial carcinoma is common among women. Several reports indicated that this cancer is influenced by androgens mediated through their receptors. The human androgen receptor gene contains a polymorphic CAG repeat in the coding region of exon 1. Other studies suggested a possible association between the CAG repeat of this gene and the development of several cancers. DNA samples isolated from 29 patients with sporadic endometrial cancer were analyzed for allelic changes in 12 highly polymorphic microsatellite loci on nine chromosomes, containing CAG repeat in the exon 1 of the androgen receptor gene. A significantly high rate of allelic change in the CAG repeat was observed (51.7%) in these patients, although the frequencies of additional loci were similar to those reported by others (0-22.2%). The changed alleles of the tumor tissue were always longer than that of normal tissue except in only one case. Since only one allele on the X chromosome is commonly active in female cells, a differential methylation assay was carried out by using genomic DNA cut with HpaII. In 14 of 15 cases, we found that the activated allele was longer in these samples from tumor tissues than those from normal tissue; in the remaining case, the length of this repeat was unchanged. The expression assays were done by using poly(A+) RNA from tumor and normal uterine tissues, revealing that an activated allele in these tumor tissues was longer than that in the normal tissues in all the cases examined. These findings suggest that expansions of the CAG repeat in the androgen receptor gene may play an important role in the carcinogenesis of uterine endometrial cells.

A single nucleotide polymorphism in the E-cadherin gene promoter alters transcriptional activities

E-cadherin plays a critical role in many aspects of cell adhesion, epithelial development, and the establishment and maintenance of epithelial polarity. The loss of the adhesive function of E-cadherin is a critical step in the promotion of epithelial cells to a more malignant phenotype. We identified a C/A single nucleotide polymorphism at -160 from the transcriptional start site of the E-cadherin gene promoter. Transient transfection experiments showed that the A allele of this polymorphism decreased the transcriptional efficiency by 68% compared with the C allele (P<0.001). Electrophoretic mobility shift and footprinting assays revealed that the C allele had a stronger transcriptional factor binding strength than the A allele. These results indicate that the -160 C/A polymorphism has a direct effect on E-cadherin gene transcriptional regulation. This allelic variation may be a potential genetic marker that can help identify those individuals at higher risk for invasive/metastatic diseases.

Homologous bladder augmentation in dog with the bladder acellular matrix graft

OBJECTIVE

To determine the functional potential and antigenicity of the homologous bladder acellular matrix graft (BAMG) in a dog model.

MATERIALS AND METHODS

Seven mongrel dogs underwent partial cystectomy (20-50%) and grafting with an equal-sized BAMG; two control animals underwent partial cystectomy (40%) only. The dogs were killed after 30 (one), 120 (one) and 210 days (five dogs). Blood samples were obtained before and at 1, 2, 4, 7, 14, 30, 90 and 210 days after surgery. The dogs underwent cystography, intravenous pyelography and ultrasonography before and after surgery, and on the day they were killed, with cystoscopy carried out just before death. The grafted tissue was assessed using routine and immunohistochemical techniques.

RESULTS

All the dogs survived surgery; a complete blood cell count, chemical panel and white blood cell count showed no significant difference between the experimental and control animals. Cystography, cystoscopy and ultrasonography revealed no pathological changes in the upper urinary tract. After 7 months, the mean bladder capacity in the augmented dogs was significantly higher (P = 0.035) than in the controls (264 vs 172 mL). Histological evaluation showed an invasion of all bladder wall components during the first month; at 7 months, the morphological examination showed essentially complete regeneration.

CONCLUSION

In this dog model, the potential of the BAMG as a bladder augmentation graft was confirmed, having minimal antigenicity with maximal acceptance. The reconstructed bladder matched the morphological and functional properties of the normal bladder.

Frequent methylation of estrogen receptor in prostate cancer: correlation with tumor progression

Prior studies have shown that the estrogen receptor (ER) gene is down-regulated in prostate cancer, but the mechanism of its inactivation is not known. We hypothesize that inactivation of the ER gene in prostate cancer is through promoter methylation. To test this hypothesis, we investigated the methylation status of the ER gene in prostate cancer cell lines, prostate cancer, and benign prostatic hyperplasia (BPH) tissues samples using the bisulfite genomic sequencing method. Our results show that the ER gene promoter was methylated in 100% (six of six) of the prostate cancer cell lines tested and all were accompanied by loss of ER mRNA expression. Treatment of these cell lines with demethylating agent 5-aza-2'-deoxycytidine restored ER mRNA expression in all of the ER-negative cell lines. In addition, elevated expression of DNA methyltransferase mRNA was found in all of the prostate cancer cell lines. Of the prostate tissue samples analyzed, 60% (6 of 10) in the BPH samples, 80% (8 of 10) in the low-grade cancer samples (grades I and II), and 95% (20 of 21) in the high-grade cancer samples (grades III-V) exhibited promoter methylation of the ER gene. The overall methylation levels in the cancer samples were higher than that in the BPH samples. The differences between the high-grade cancer samples and BPH samples were significant at all CpG sites. Only at three CpG sites were the differences significant between the low-grade cancer samples and BPH samples. This study presents the first evidence that ER gene is transcriptionally inactivated by DNA methylation in prostate cancer. Our data suggest that ER may be involved in the pathogenesis of prostate cancer, as well as BPH.

Temporal bone fractures: otic capsule sparing versus otic capsule violating clinical and radiographic considerations

OBJECTIVE

To assess the practicality and utility of the traditional classification system for temporal bone fracture (transverse vs. longitudinal) in the modern Level I trauma setting and to determine whether a newer system of designation (otic capsule sparing vs. otic capsule violating fracture) is practical from a clinical and radiographic standpoint.

METHODS

The University of Massachusetts Medical Center Trauma Registry was reviewed for the years 1995 to 1997. Patients identified as sustaining closed head injury were reviewed for basilar skull fracture and temporal bone fracture. Clinical and radiographic records were evaluated by using the two classification schemes.

RESULTS

A total of 2,977 patients were treated at the trauma center during this time. Ninety (3%) patients sustained a temporal bone fracture. The classic characterization of transverse versus longitudinal fracture (20% vs. 80%, respectively) was unable to be determined in this group; therefore, clinical correlation to complications using that paradigm was not possible. By using the otic capsule violating versus sparing designation, an important difference in clinical sequelae and intracranial complications became apparent. Compared with otic capsule sparing fractures, patients with otic capsule violating fractures were approximately two times more likely to develop facial paralysis, four times more likely to develop CSF leak, and seven times more likely to experience profound hearing loss, as well as more likely to sustain intracranial complications including epidural hematoma and subarachnoid hemorrhage.

CONCLUSION

The use of a classification system for temporal bone fractures that emphasizes violation or lack of violation of the otic capsule seems to offer the advantage of radiographic utility and stratification of clinical severity, including severity of Glasgow Coma Scale scores and intracranial complications such as subarachnoid hemorrhage and epidural hematoma.

High frequency of deletion on chromosome 9p21 may harbor several tumor-suppressor genes in human prostate cancer

Chromosome 9p has been reported to be a critical region of loss in various cancers. Our present study was designed to determine the frequency of deletions at different loci of chromosome 9p in microdissected samples of normal prostatic epithelium and carcinoma from the same patients. For this purpose, DNA was extracted from the microdissected sections of normal and tumor cells of 40 prostate specimens, amplified by PCR and analyzed for loss of heterozygosity (LOH) on chromosome 9p using 15 microsatellite markers. Only 6 of 15 microsatellite markers exhibited LOH in prostate cancer specimens (D9S162, D9S1748, D9S171, D9S270, D9S273 and D9S153). LOH on chromosome 9p was identified in 29 of 40 cases (72.5%) with at least 1 marker. The main deletion was found on 9p21, at loci D9S1748 (50%), D9S171 (51.4%) and D9S270 (21.8%). There was also a deletion on 9p22 at locus D9S162 (8.3%), on 9p13 at locus D9S273 (13.8%) and on 9p11 at locus D9S153 (7.7%). LOH data were correlated with stage of prostate cancer and revealed a high frequency of LOH at 3 or more loci in samples with stage T(3)N(0)M(0) (46%) compared with stage T(2)N(0)M(0) (15%), which suggests a higher incidence of LOH in the advanced stage of prostate cancer. One of the candidate target tumor-suppressor genes, p16 (MTS-1/CDKN2), has been identified within the 9p21 deleted region in tumor cell lines. Expression of P16 protein was either absent or very low in prostate cancer samples, suggesting that loss of the p16 gene may be involved in prostatic carcinogenesis.

Differential gene expression of growth factors in young and old rat penile tissues is associated with erectile dysfunction

The molecular mechanisms of erectile dysfunction with aging are unclear. Recent studies have suggested that growth factors may play a role in the etiology of erectile dysfunction. This present study was designed to test the hypothesis that gene expression of various growth factors such as TGF alpha, TGF beta 1, TGF beta 2, TGF beta 3, IGF and NGF modulate with aging in rat penile tissues. For this purpose, total RNA was extracted from young and old rat penile tissues and the gene expression for these growth factors was determined by differential reverse-transcriptase-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. mRNA levels of growth factors were quantified by using beta-actin as an internal standard. The results of these experiments suggest that: (1) young and old rat penile tissues expressed mRNA transcripts for TGF alpha, TGF beta 1, TGF beta 2, TGF beta 3, IGF and NGF; (2) TGF beta 1 gene expression was significantly increased in old rat penile tissues as compared to young; (3) mRNA transcripts for NGF and TGF beta 3 were significantly lower in old rat penile tissues as compared to young; and (4) TGF alpha, TGF beta 2 and IGF mRNA expression did not change in young and old rat penile tissues. These results suggest that the differential gene expression for various growth factors in young and old rat penile tissues may be important in understanding the pathophysiology of erectile dysfunction associated with aging.

The effects of colchicine on a Peyronie's-like condition in an animal model

PURPOSE

We have developed an animal model of Peyronie's disease by injecting transforming growth factor beta (TGF-beta) into the rat penis. Our objective is to study the effects of colchicine on the Peyronie's condition in an animal model.

MATERIALS AND METHODS

Thirty-six adult male Sprague-Dawley rats received TGF-beta injections into the tunica albuginea and were divided into two groups (n = 18 each). Rats in the first group were divided into three subgroups (n = 6 each). Each rat in the three subgroups received the following: Subgroup 1 received colchicine, subgroup 2 received ibuprofen, and subgroup 3 received regular water. The rats were euthanized after 6 weeks. Rats in the second group were also divided into three subgroups. These rats received the same treatments as the rats in the first group, but treatments began 6 weeks after TGF-beta injection. These rats were euthanized after 12 weeks. Tunical tissue samples were collected and examined using Hart and trichrome stains, electron microscopy (EM), and western blot analysis for TGF-beta detection.

RESULTS

In the first group, the colchicine-treated rats exhibited less collagen deposition and less elastic fiber fragmentation than the untreated or ibuprofen-treated rats. EM confirmed the results and showed normal distribution and shape of both collagen and elastic fibers in the colchicine-treated group. In the second group, the colchicine-treated rats exhibited less crowding of the collagen fibers. However, the elastic fibers remained fragmented and scarce. Western blot analysis showed significant down-regulation of TGF-beta expression (5/6) in the colchicine-treated group after 6 weeks. Down-regulation was observed in only 1/6 in both ibuprofen and non-treated groups. After 12 weeks 2/6, 1/6, and 1/6 rats displayed down regulation in the colchicine treated, ibuprofen treated, and non-treated groups, respectively.

CONCLUSION

Early colchicine treatment may suppress a Peyronie's like condition in the rat animal model.

Effects of diabetes on nitric oxide synthase and growth factor genes and protein expression in an animal model

Erectile dysfunction occurs frequently in humans with diabetes mellitus; the molecular basis of this phenomenon is not known. We investigated the effects of diabetes on penile erection, nitric oxide synthase and growth factors expression in an animal model. Forty male rats were divided into two groups: the experimental group (n = 30) received intraperitoneal injection of Streptozotocin (STZ) dissolved in citrate buffer to induce diabetes; ten age-matched control rats received injection of citrate buffer vehicle only. Before euthanization at eight weeks, erectile function was assessed by electrostimulation of the cavernous nerves. NADPH diaphorase staining was used to identify NOS and immunostaining technique was used to identify nNOS in the penile nerve fibers. RT-PCR was used to identify mRNA expression of nNOS, eNOS, iNOS, ER-beta, ER-alpha, NGF, IGF-I, TGF-beta 1, and AR. Western blot was used to identify nNOS, IGF-I, NGF, and TFG-beta protein expressions. In the diabetic group, there was: (1) a significant decrease in NOS containing nerve fibers in the dorsal and intracavernosal nerves; (2) a significant lower maximal intracavernosal pressure. RT-PCR showed down-regulation of nNOS (large form), iNOS and ER-beta mRNA expression, Immunoblot showed down-regulation of nNOS protein expression and nNOS immunostaining showed less positive staining in the dorsal and intracavernous nerves in the diabetic group. These molecular changes may provide the basis for further studies to explore the association between diabetes and impotence.

Molecular prognostic markers in breast cancer

Based on the scientific literature, there are several molecular markers which might be used for the prognosis of breast cancer. Possible molecular prognostic markers are: BRCA-1, BRCA-2, p53, erbB oncogenes, loss of heterozygosity (LOH), chromosomal aberrations, microsatellite instability, transforming growth factor alpha (TGFalpha), and the multiple drug resistance (MDR) gene. In this chapter, we discuss the possible role of these prognostic markers in breast cancer.

Loss of two new loci on chromosome 8 (8p23 and 8q12-13) in human prostate cancer

Inactivation of tumor suppressor genes due to allelic loss is thought to be an important mechanism of gene alterations in prostatic carcinogenesis. Loss of sequences on the short arm of chromosome 8 (8p) has been reported in human cancers, especially of 8p22 and 8p12-21 in prostate cancer. By using PCR analysis of polymorphic microsatellite repeat markers at four 8p loci and three 8q loci in 60 tumors, we observed deletion of sequences at two other deletion domains (8p23, and 8q12-13). There was loss in 51 of 60 cases (85%) with at least one marker. Four distinct regions of loss detected were: i) at 8p23, at locus D8S262; ii) at 8p22, on locus D8S259; iii) at 8p12, on loci D8S255 and D8S285; iv) at 8q12-13, on loci between D8S260 and D8S528. We found that 29% of the tumors showed LOH at 8p23; 19% LOH on 8p22; 54% had LOH at 8p12; and 48% had LOH at 8q12-13. There was higher frequency of LOH at 3 or more loci in samples of T3 stage (62%) as compared to T2 stage (13.3%) which suggests higher incidence of LOH in advanced stage of prostate cancer. We report deletion of two novel loci at 8p23 and 8q12-13, these regions may contain putative tumor suppressor genes in prostate cancer.

An in vivo study of antifreeze protein adjuvant cryosurgery

Cryosurgery employs freezing to destroy undesirable tissue. However, under certain thermal conditions, frozen tissues survive. The survival of frozen undesirable tissue may lead to complications, such as recurrence of cancer. In a study of nude mice with subcutaneous metastatic prostate tumors, we showed that the preoperative injection of a phosphate-buffered saline solution with 10 mg/ml antifreeze protein of type I into the tumor prior to freezing enhances destruction under thermal conditions which normally yield cell survival. This suggests that the adjunctive use of antifreeze proteins in cryosurgery may reduce the complications from undesirable tissues that survive freezing.

Effect of thermal variables on human breast cancer in cryosurgery

There is a growing interest in the use of cryosurgery to treat breast cancer, following recent breakthroughs in noninvasive imaging and in cryotechnology, as well as the recent success of cryosurgery in treating various types of cancer. However, since haphazard freezing does not guarantee tissue destruction, in order to apply this technique effectively it is essential to determine the thermal parameters that produce complete destruction of malignant tissue. This study seeks to quantitatively identify the relationship between thermal variables and the degree of freezing damage to human breast cancer cells. In order to do this, human breast cancer and normal cells were frozen with controlled thermal parameters using a directional solidification apparatus. Cell viability was determined after thawing using trypan blue, and correlated to the thermal variables used during freezing. Cellular damage is observed to increase with increasing cooling rates, due to the higher probability of intracellular ice formation. A double freeze thaw cycle significantly increases the extent of cell damage, and is sufficient to ensure complete cell destruction at final freezing temperatures of -40 degrees C for a 25 degrees C/min cooling rate, and -20 degrees C for a 50 degrees C/min cooling rate. The correlations between cell death and thermal parameters are qualitatively identical for all the cell types in this study, although there is some variation from one cell type to another in the overall susceptibility to freezing damage. The correlations established in this study can be used to design systematic and optimal breast cryosurgery protocols.

Bladder acellular matrix graft: in vivo functional properties of the regenerated rat bladder

The purpose of this study was to determine whether the rat urinary bladder augmented by an acellular matrix graft can restore the bladder's low-pressure reservoir function and preserve normal micturition. After partial cystectomy (> 50%) and grafting with the bladder acellular matrix graft (BAMG), storage and voiding functions were monitored in 20 rats by means of a specially designed "micturition cage," leak-point cystography, and cystometry. After 4 months, sections (n = 6) were examined histologically to evaluate regeneration of bladder wall components within the BAMG. Bladder capacity and compliance increased progressively and were significantly higher in the grafted animals than in controls (partial cystectomy only), and volumes per void were significantly higher than in either control or normal animals. At 4 months, the regenerated urothelium, smooth muscle, blood vessels and nerves within the BAMG were qualitatively identical to normal bladder wall. Augmentation cystoplasty with the homologous BAMG leads to morphologic and functional rat bladder regeneration, thus enhancing low-pressure reservoir function and preserving normal micturition.

Effect of cavernous nerve freezing on protein and gene expression of nitric oxide synthase in the rat penis and pelvic ganglia

PURPOSE

Cryoablation of the prostate has been reported to induce impotence as a result of cavernous nerve injury. This study is designed to investigate the early and late effects of cavernosal nerve cryoablation on erectile function and nitric oxide synthase (NOS) containing nerves in the rat penis and pelvic ganglia.

MATERIALS AND METHODS

Forty male rats were divided into two groups (n = 20 each). The first group underwent unilateral cavernous nerve freezing (experimental group). Before their euthanization at 1 and 3 months (10 rats each), erectile function was assessed by electrostimulation of the cavernous nerves. The second group served as a control and was euthanized at the same time points. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was used to identify NOS in the penile nerve fibers of the mid-shaft segment and neurons of the pelvic ganglia. Western blot, RT-PCR and immunostaining techniques were used to identify protein and gene expression of eNOS, iNOS, and nNOS.

RESULTS

One month after unilateral cavernosal nerve freezing, there was a significant decrease in NOS-containing nerve fibers in the dorsal and intracavernosal nerves and ipsilateral pelvic ganglia as compared with the intact side. At three months, the number of NOS containing nerve fibers in the above-mentioned nerves and ganglia showed a significant increase on the frozen side but not the intact side. Electrostimulation of the frozen nerve after three months revealed a significantly higher maximal intracavernosal pressure and a shorter latency period than the one-month group. At three months, immunoblot showed up-regulation of eNOS and nNOS protein expression in the penile tissue. RT-PCR showed up-regulation of nNOS gene expression in the pelvic ganglia of the frozen side. Immunostaining confirmed the results of western blot and showed significant increase of the nNOS positive staining in the frozen side of the penile tissue after three months. There was no difference in iNOS after three months between both sides. Our repeated eNOS immunostaining was not successful.

CONCLUSIONS

The results show that intracavernous pressure response to neurostimulation markedly decreased at one month and then partially recovered three months after cavernosal nerve freezing. A similar pattern of changes of the NOS-containing nerve fibers in dorsal nerves, intracavernosal nerves, and pelvic ganglia were observed. This alteration in erectile function and NOS-containing nerves was associated with differential gene and protein expression of the three subtypes of NOS.

Possible molecular mechanisms of cryoablation-induced impotence in a rat model

OBJECTIVES

Cryoablation of the prostate has been reported to induce impotence as a consequence of cavernosal nerve injury. This study is designed to investigate the early and late effects of cavernosal nerve cryoablation on growth factor expression and erectile function in a rat model.

METHODS

Forty male rats were divided into two groups (n=20 each). The first group underwent unilateral cavernosal nerve freezing (experimental group). Before their euthanization at 1 and 3 months (10 rats each), erectile function was assessed by electrostimulation of the cavernous nerves. The second group served as the control and was killed at the same time points. Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were used to identify protein and gene expression of nerve growth factor (NGF), transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1) in the rat penis and pelvic ganglia.

RESULTS

Electrostimulation of the frozen nerve after 3 months revealed a significantly higher maximal intracavernosal pressure and a shorter latency period than in the 1-month group. At 3 months, immunoblot showed upregulation of NGF, TGF-alpha, and the precursor form of IGF-1 protein expression in the penile tissue; RT-PCR showed downregulation of NGF gene expression in the pelvic ganglia of the frozen side.

CONCLUSIONS

The results show that erectile function decreased at 1 month and then partially recovered 3 months after cavernosal nerve freezing. This alteration in erectile function was associated with differential gene and protein expression of the growth factors (NGF, TGF-alpha, EGF, and IGF-1). Further studies are required to elucidate the potential role of these growth factors in the prevention and treatment of cryoablation-induced impotence.

Expression of TGF-beta-1 mRNA and ultrastructural alterations in pharmacologically induced prolonged penile erection in a canine model

PURPOSE

Transforming growth factor beta (TGF-beta) is known to induce fibrosis. Our objective was to study the role of TGF-beta as a possible mediator of fibrosis that may follow prolonged penile erection.

MATERIALS AND METHODS

Prolonged penile erection was induced in seven adult male mongrel dogs by intracavernosal injection of papaverine into one of the corpora cavernosa while the other was used as a control. Intracavernosal pressure measurements were carried out prior to administration of papaverine and at the end of the procedure. Penile tissue was collected from anesthetized animals prior to euthanasia for histological and electron microscopic (EM) studies. RT-PCR was carried out for detection of mRNA on same tissue samples.

RESULTS

The light microscopy showed stasis of blood in the cavernosal sinusoids. EM studies revealed sporadic endothelial defects, loss of plasma membrane integrity and cytoplasmic condensation. There was expression of TGF-beta1 mRNA in 66.7% of the experimental group compared with 16.7% of the control group.

CONCLUSIONS

Pharmacologically induced low flow prolonged penile erection in canine models is associated with histomorphological changes in relatively short periods of time, suggesting that early therapeutic intervention is desirable. The gene expression for TGF-beta1 may be a mediator of fibrosis; therefore the use of anti-TGF-beta agents presents a possible tool for therapeutic intervention.

Composition and biomechanical properties of the bladder acellular matrix graft: comparative analysis in rat, pig and human

OBJECTIVE

To compare the composition and mechanical properties of the newly developed bladder acellular matrix graft (BAMG) with the normal urinary bladder in rat, pig and human.

MATERIALS AND METHODS

Rat, pig and human urinary bladders were harvested and divided into control and experimental groups. For the latter, BAMGs were prepared, and light and transmission electron microscopic studies performed. Strips from the normal bladders and the BAMGs (10 in each group) were tested under tension, and the ultimate tensile strength, maximum strain, and elastic modulus were determined from stress/strain curves.

RESULTS

Both types I and III collagen, as well as elastic fibres, were observed as major components of the matrix scaffold. There were more collagen type I fibres in the rat than in the pig and human BAMGs, whereas the pig, and particularly the human, both showed higher levels of type III collagen and elastic fibres. These different matrix scaffold patterns were confirmed by electron microscopy. Results from biomechanical testing showed no significant differences for strength, strain or elastic modulus between BAMG and control bladder strips, except in the rat where the maximum strain values were significantly lower.

CONCLUSION

There are variations in the acellular matrix structure with similar biomechanical properties between the BAMG and the normal urinary bladder in three different species. These results may underscore the potential of the BAMG. Furthermore, this in vitro model provides a suitable method to study the mechanical properties of the urinary bladder and may serve as a diagnostic tool for various investigations.

Species-specific detection of growth factor gene expression in developing murine prostatic tissue

The aim of the present study was to develop a method by which the expression of paracrine signaling molecules could be localized to either epithelial or stromal cells of developing prostatic tissue. Heterospecific tissue recombinants composed of mouse urogenital epithelium (mouse UGE) plus rat urogenital mesenchyme (rat UGM) and the reciprocal tissue recombinants, rat urogenital epithelium (rat UGE) plus mouse urogenital mesenchyme (mouse UGM), were grafted under the renal capsule in intact, athymic male mouse and rat hosts. After 2 wk of growth, RNA from the grafts was analyzed by species-specific reverse transcription-polymerase chain reaction for the expression of the mRNA for the following molecules: transforming growth factors beta1, beta3, and alpha; epidermal growth factor; epidermal growth factor receptor; and keratinocyte growth factor. The species of expression of these growth factor and receptor gene products within the heterospecific tissue recombinants was identified, allowing determination of the cell layer in which the genes were expressed. Identification of the tissue-specific expression of the growth factor and growth factor receptor profiles of the epithelium and mesenchyme of this in vivo model provides a basis for understanding the autocrine and paracrine mediators of cell-cell interactions in prostatic development.

Interactions between adult human prostatic epithelium and rat urogenital sinus mesenchyme in a tissue recombination model

Tissue recombinants composed of adult human prostatic epithelium (hPrE) and rat urogenital sinus mesenchyme (rUGM) were grafted beneath the renal capsule of athymic rodent hosts. The pseudostratified human epithelium initially became multilayered, solid epithelial cords emerged, grew into the surrounding mesenchyme and canalized to regenerate a pseudostratified epithelium. Basal cells expressed cytokeratins 5 and 14, while luminal cells expressed cytokeratins 8 and 18, prostate specific antigen and prostatic acid phosphatase. The rat mesenchymal component differentiated into thick sheets of smooth muscle, characteristic of the human but not the rat prostate. These findings indicate that epithelial-mesenchymal interactions were reciprocal. Rat UGM induced adult hPrE to form new ductal-acinar tissue, involving epithelial proliferation, ductal branching morphogenesis and functional cytodifferentiation. Concurrently the epithelium dictated smooth muscle differentiation and patterning. Species-specific reverse transcriptase polymerase chain reaction SC (RT-PCR) analysis of the tissue recombinants was performed to separately examine the expression of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), epidermal growth factor receptor (EGFR), TGF-beta 1, and TGF-beta 3 in the epithelium, stroma and host components of the graft. All of these genes, except TGF-beta 1, were expressed in all three tissues. Human TGF-beta 1 was not detected, indicating that this gene was not expressed in human prostatic epithelium but was present in stroma.

Microsatellite instability in an animal model of mammary carcinogenesis

Alterations in the length of simple repetitive genomic sequences (microsatellite instability, MSI) may characterize a distinct mechanism of mammary carcinogenesis. In order to investigate whether MSI is associated with chemically-induced mammary carcinogenesis in the rat, 30 microdissected mammary carcinomas were analyzed using 27 different microsatellite markers from chromosomes 1, 3, 5, 7 and 8. DNA was extracted from rat mammary cancer and adjoining microscopically normal tissues from the same slide, amplified by PCR, using different polymorphic DNA markers and the reaction products were analyzed for microsatellite instability. The results of this study indicate that 30% of cases (9 out of 30) showed microsatellite instability at a minimum of 1 locus. Three cases (out of 30) showed microsatellite instability at only three loci or less, called MSI-L (low frequency MSI). Six cases (out of 30) showed MSI at four loci or more, called MSI-H (high frequency MSI). Six cases showed MSI at D5Mit11 and D5Mgh3 loci, five cases showed MSI at D1Mit14, D1Mgh6, D5Mgh5 and D8Mgh10 loci, four cases had MSI at D1Mgh2, and D3Mgh7 loci, three cases had MSI at D3Mit3, D3Mgh5, D7Mgh1 loci, two cases had MSI at D7Mit11 locus and one case had MSI at D3Mgh9 locus. The results of these experiments suggest that MSI may be an important etiological event in the pathophysiology of mammary carcinogenesis.

In vitro functional properties of the rat bladder regenerated by the bladder acellular matrix graft

PURPOSE

To assess the response of rat urinary bladder regenerated by the homologous bladder acellular matrix graft (BAMG) to in vitro electrical and pharmacologic stimuli.

MATERIALS AND METHODS

In Sprague-Dawley rats, partial cystectomy (>50%) was performed, followed by BAMG augmentation cystoplasty. After 4 months, organ bath studies of tissue strips in 10 were used to compare the contractility of the BAMG regenerates and the corresponding host detrusor smooth muscle.

RESULTS

The BAMG regenerates exhibited contractile activity to electrical field stimulation and a qualitatively identical pattern of response to muscarinic, purinergic, alpha- and beta-adrenergic drug administration and nitric oxide. At 4 months after surgery, the maximum forces of contraction of the BAMG regenerates to carbachol stimulation amounted to close to 80% of the host bladder response. With electrical field stimulation, they equaled 44% and 62% of the host bladder response after 2.5 and 4 months, respectively. Histological and immunohistochemical studies confirmed the presence of receptors for neurotransmitters that these functional in vitro studies implied.

CONCLUSIONS

The present study provides further evidence that augmentation cystoplasty with the BAMG leads to functional regeneration of the rat bladder detrusor smooth muscle.

The effect of surgical trauma on rat tunica albuginea

PURPOSE

Increased TGF-beta1 protein expression in tunica albuginea has been found to be associated with Peyronie's disease. The present study is designed to investigate whether surgical trauma induces TGF-beta up-regulation and histological changes in rat penis.

MATERIALS AND METHODS

Thirty-two adult male Sprague-Dawley rats were divided into two groups. The first group (n=24) underwent incision and suture repair of the tunica albuginea of the penis. The second group (n=8) received sham surgery (incision of the penile skin and underlying fascia) as the control group. The trauma-induced group was divided into four subgroups in which the rats were euthanized at 6 hours (n=6), 1 day (n=6), 3 days (n=6), and 8 weeks (n=6). Two sham-operated (control) animals were also euthanized at each of the above time points. All tunical tissues from the trauma-induced and sham-operated rats were collected and examined histologically using Trichrome and Hart elastic fiber stain. Electron microscopy was used to study the ultrastructural changes of both trauma induced and control specimens. Western blotting technique was performed to study TGF-beta protein expression in both experimental and sham-operated groups.

RESULTS

Tissue edema and hemorrhage between collagen bundles are noted in the experimental groups after 6 hours, 1 day and 3 days. At 8 weeks the most prominent changes observed were inflammatory cellular infiltration and disorganization of the collagen bundles. In the control group the tunica albuginea retains normal wavy regular appearance in all rats. This histological analysis is similar to the reported description of histological features of the acute phase of Peyronie's disease. Electron microscopy showed packed collagen bundles in the trauma-induced group with normal appearing elastic fibers. No abnormal change was detected in the control group. Immunoblot results revealed remarkable TGF-beta1 protein expression in 1, 5, 3, and 0 rats of trauma induced subgroups after 6 hours, 1 day, 3 days, and 8 weeks respectively. No TGF-beta1 protein expression in any rats in the control group was detected. No significant TGF-beta2 or TGF-beta3 protein expression was observed either in the trauma induced group or in the control group.

CONCLUSION

Trauma can induce histological changes similar to the acute phase of Peyronie's disease but not the overt picture of the chronic phase of Peyronie's disease. It can also result in an early but transient up-regulation of TGF-beta1 protein expression in the rat penis. We conclude that surgical incisional trauma does not result in Peyronie's disease-like changes in the tunica.

Functional rat bladder regeneration through xenotransplantation of the bladder acellular matrix graft

OBJECTIVE

To determine the decreased antigenicity of the bladder acellular matrix graft (BAMG) through xenotransplantation and to assess the in vivo and in vitro functional properties of the rat urinary bladder thus regenerated.

MATERIALS AND METHODS

After partial cystectomy (> 50%), BAMGs prepared from hamster, rabbit and dog urinary bladders were grafted to male and female Sprague-Dawley rats; 10 control rats underwent partial cystectomy only. Urinary storage and voiding function were monitored in 15 animals using a specially designed 'micturition cage' and cystometry. After 4 months, organ-bath studies and histological techniques were used to evaluate bladder regeneration in vitro in the grafted animals.

RESULTS

Clinically relevant antigenicity was not evident; no animal died from rejection and all bladder wall components regenerated in all BAMG xenografts. However, the degree and quality of regeneration varied. Muscularization, peak pressure, and bladder capacity were higher in the hamster BAMG-grafted animals, whereas in vitro contractility and compliance were best in the dog BAMG-regenerated bladders. All grafted bladders had significantly better capacity and compliance than the autoregenerated bladders after partial cystectomy alone.

CONCLUSIONS

The present in vivo and in vitro studies show that BAMG-augmentation cystoplasty can lead to morphological and functional regeneration of the rat bladder, preserving its low-pressure reservoir function. Because BAMG-regenerated bladders show functional innervation that is similar to normal bladders, they can work in coordination with the host bladder components, thus generating adequate intravesical pressure to produce sustained voiding. The decreased antigenicity makes heterologous BAMG transplants feasible without immunosuppression.

Multiple sites of loss of heterozygosity on chromosome 8 in human breast cancer has differential correlation with clinical parameters

Recent studies have shown that chromosome 8p21-22 is the main site of frequent loss of heterozygosity (LOH) in breast cancers. However, the detailed molecular analysis of chromosome 8 so far in breast cancer has been variable. Most of the literature pertaining to LOH in breast cancer is mainly on short arm of chromosome 8. In the present study, we have examined LOH on both short and long arm of chromosome 8 using fifteen different polymorphic DNA markers in microdissected samples of normal breast epithelium and carcinoma from the same patients. For this purpose, DNA was extracted from the microdissected normal and tumor cells of 66 breast cancers, amplified by PCR and analyzed for LOH on chromosome 8 using fifteen different polymorphic DNA markers (D8S264, D8S298, D8S535, D8S255, D8S1098, D8S589, D8S567, D8S591, D8S285, D8S1102, D8S1763, D8S260, D8S530, D8S1772, and D8S1844). Expression of estrogen receptor, progesterone receptors, and p53 antigens was determined by immunohistochemistry using specific monoclonal antibodies. The results of this study suggest that LOH on chromosome 8 was identified in 40 of 66 cases (61%) with at least one marker. Three distinct regions of loss detected were: i) at 8p12, at loci between D8S535 and D8S255; ii) at 8p11, on loci D8S567, D8S591, D8S285, and D8S1102; iii) at 8q11-12, on loci D8S1763, D8S260 and D8S530. We found 45% (30 out of 66 informative cases) of the tumors showed LOH at 8p12; 52% (34 out of 66 informative cases) had LOH at 8p11; and 39% (26 out of 66 informative cases) had LOH at 8q11-12. Deletion at 8q11-12 was significantly correlated with the grade of the breast cancer specimens. Moderate to poorly differentiated specimens had higher incidence of LOH at 8q11-12 as compared to well differentiated specimens. Deletion at 8p12 and 8p11 was significantly higher in clinical stages III and IV of breast cancer tissues as compared to stage I and II cases. Tissues with lymph node involvement showed higher incidence of LOH at 8p12 as compared to the tissues with no lymph node involvement. There was no correlation of LOH at these loci with either the age of the patients, tumor size, BrdU labeling index, expression of estrogen receptor, progesterone receptor, and p53 in breast cancer specimens. These experiments, for the first time, report multiple sites of LOH on chromosome 8 in human breast cancer, and these deletions have differential correlation with clinical parameters of breast cancer samples.

A novel p53 mutation hotspot at codon 132 (AAG-->AGG) in human renal cancer

Mutations of p53 tumor suppressor gene are the most common genetic alterations in a variety of human carcinomas. The sites of p53 mutations, however, vary in different cancers. The present study was designed to characterize p53 mutations in 40 primary human renal cancer specimens using hot-start-PCR-single-strand conformation polymorphism (SSCP) analysis, sequencing of PCR product and immunohistochemistry. DNA extracted from microdissected paraffin-embedded sections was amplified by hot-start-PCR using oligonucleotide primers specific for exons 4-9 of p53. The mutations were analyzed by PCR-SSCP technique and the generated fragments were denatured and analyzed by 6% polyacrylamide gel electrophoresis. The samples showing a band shift were denatured and sequenced using the Sequenase Version 2.0 DNA Sequencing Kit (US Biochemical, Cleveland, Ohio). Genomic DNA from control samples containing wild-type p53 alleles was sequenced in parallel for confirming mutations in samples that were positive for p53 in the PCR-SSCP analysis. The results of these experiments demonstrate that: (1) there were mutations in p53 exon 5 and 8 in 35% (14 out of 40 samples) of human renal cancer tissues as revealed by PCR-SSCP analysis; (2) DNA sequencing of samples showing frame-shift have hot spot of p53 mutation on exon 8 at codon 244 (GGC-->TGC) and exon 5 at codon 132 [AAG (Lys)-->AGG (Arg)]. This mutation in p53 exon 5 at codon 132 is novel and has not yet been reported; (3) immunohistochemical staining of p53 in renal cancer tissue using mouse anti-human p53 monoclonal antibody, clone PAb 1801, correlated with the p53 mutation assessed by PCR-SSCP. No correlation was found between p53 mutations and tumor stage and grade of renal cancer.

An animal model of Peyronie's-like condition associated with an increase of transforming growth factor beta mRNA and protein expression

PURPOSE

Transforming growth factor beta (TGF-beta) is involved in numerous vital processes including tissue fibrosis. Our objective was to study the role of TGF-beta in the induction of a Peyronie's-like condition and to produce an animal model for the further study of Peyronie's disease.

MATERIALS AND METHODS

Twenty-four adult male Sprague-Dawley rats were divided into two groups. Different concentrations of cytomodulin, a synthetic heptopeptide with TGF-beta-like activity, were injected into the tunica of each rat from the first group (n = 18). Rats in the second group (n = 6) received saline injections as a control. The tunical tissues were taken after 3 days, 2 weeks, and 6 weeks and were examined using Hart and Trichrome stains. In the same tissue samples, TGF-beta mRNA and protein expression were studied.

RESULTS

Histological alterations were observed in 15 out of 18 cytomodulin-injected rats, especially in tissue examined after 6 weeks. The most prominent changes were chronic cellular infiltration, focal and diffuse elastosis, thickening, disorganization and clumping of the collagen bundles. Results from immunoblot revealed remarkable TGF-beta1 protein expression in all the cytomodulin-injected rats only after 2 and 6 weeks. No remarkable TGF-beta2 or TGF-beta3 protein expression was observed. TGF-beta1 mRNA expression in the cytomodulin-injected rats was noticed in rats injected with higher concentrations after 3 days, while it was expressed in all rats after 2 weeks. There was no expression in the control group after either 3 days or 2 weeks.

CONCLUSIONS

Cytomodulin can induce Peyronie's-like condition in the rat penis, which may explain the role of TGF-beta in the pathogenesis of Peyronie's disease.

Free ureteral replacement in rats: regeneration of ureteral wall components in the acellular matrix graft

OBJECTIVES

To evaluate ureteral replacement by a free homologous graft of acellular matrix in a rat model.

METHODS

In 30 male Sprague-Dawley rats, a 0.3 to 0.8-cm midsegment of the left ureter was resected and replaced with an acellular matrix graft of equal length placed on a polyethylene stent. The animals were killed at varying intervals, and the grafted specimens were prepared for light and electron microscopy.

RESULTS

In all animals, the acellular matrix graft remained in its original position without evidence of incrustation or infection, and histologic examination showed complete epithelialization and progressive infiltration by vessels. At 10 weeks, smooth muscle fibers were observed; at 12 weeks, nerve fibers were first detected; at 4 months, smooth muscle cells had assumed regular configuration.

CONCLUSIONS

The ureteral acellular matrix graft appears to promote the regeneration of all ureteral wall components.

Peyronie's disease is associated with an increase in transforming growth factor-beta protein expression

PURPOSE

Transforming growth factor-beta (TGF-beta) has been implicated in many chronic fibrotic conditions such as pulmonary and hepatic fibrosis. We postulated that TGF-beta may play a role in the pathogenesis of Peyronie's disease.

MATERIALS AND METHODS

Tissues from the tunica albuginea of 30 Peyronie's disease patients (study group) and from 6 patients without Peyronie's disease, who had undergone penile prosthesis surgery for organic impotence (control group), were subjected to histological examination using Hart and trichrome stains and Western blotting for the detection of TGF-beta protein expression.

RESULTS

The results of these experiments demonstrate that all tissue from Peyronie's disease patients showed a variety of histological changes of the tunica, ranging from chronic inflammatory cellular infiltration to complete calcification and ossification of the tissues. The most prominent changes observed in the majority of patients were focal or diffused elastosis, fenestration and disorganization of the collagen bundles. TGF-beta1 protein expression was detected in 26 patients (86%), while only 7 (23%) and 5 (17%) patients showed TGF-beta2 and TGF-beta3 protein expression, respectively. One patient in the control group showed fibrosis of the tunica albuginea and protein expression of TGF-beta1 and TGF-beta2. This patient had undergone surgery for the revision of his prosthesis twice. Five patients from the control group showed normal histological patterns of the tunica albuginea and no protein expression for TGF-beta1, TGF-beta2 and TGF-beta3.

CONCLUSIONS

TGF-beta1 protein expression is significantly associated with Peyronie's disease, which may provide a new insight and the potential for the prevention and treatment of this disease.

High frequency of genetic instability of microsatellites in human prostatic adenocarcinoma

In order to investigate the genomic instability associated with prostate cancer, 36 microsatellite marker loci on chromosomes 1p, 3p, 5q, 8p, 8q, 9p, 11q and 13q were analyzed using microdissected samples from prostate cancer and adjoining microscopically normal tissues from the same slide. DNA was extracted from the normal and tumor cells of 40 microdissected prostate-cancer samples, amplified by PCR, and analyzed for microsatellite instability (MSI) using 36 different polymorphic DNA markers. In the present study, we have utilized a highly refined technique of PCR product separation on a sequencing gel, developed in our laboratory, which clearly shows high-quality results for the microsatellite instability in prostate cancer. The results of this study suggest that 45% (18 out of 40) showed genomic instability at a minimum of 1 locus; 4 cases each showed MSI at one and 2 loci, 4 cases had MSI at 3 loci, 3 cases showed MSI at 5 loci, while one case each showed MSI at 7, 8 and 15 loci. There was no significant correlation between the MSI and stage or grade of the tumors. This extensive study on genomic instability in prostate cancer found the occurrence of MSI to be very high, which suggests a role of MSI in the pathophysiology of prostate cancer.

mRNA and protein expression of nitric oxide synthase and adrenoceptor alpha 1 in young and old rat penile tissues

OBJECTIVE

To investigate alterations of neuronal structure and the mRNA expression of nitric oxide synthase (NOS) and adrenoceptor alpha 1 in young and old rat penile tissues, and assess the importance of these factors in erectile dysfunction (ED) associated with ageing.

MATERIALS AND METHODS

NOS was determined in the pelvic ganglia of 32 rats using nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining. Adrenergic neurons were identified by histofluorescence staining. The gene expression for NOS and for adrenoceptor alpha 1 was investigated in corporal tissue by differential reverse transcriptase-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. b-actin was used as an internal standard in each tube to quantify the baseline gene expression.

RESULTS

The following changes occurred in old rats: (i) an increase of lipofuscin and a decrease in both bNOS-containing neurons and fluorescent adrenergic neurons in the pelvic ganglia; (ii) significantly less expression of NOS mRNA than in young rat penile tissues; and (iii) no significant alteration in adrenoreceptor alpha 1 mRNA expression.

CONCLUSIONS

The fewer adrenergic and NOS-containing neurons and neurotransmitters in pelvic ganglia from old rats may explain the enhanced penile smooth muscle tone previously reported in older impotent men. Furthermore, lower mRNA expression of NOS may be associated with structural and functional changes associated with ageing penile tissue.

Deletion of chromosome 11p15, p12, q22, q23-24 loci in human prostate cancer

Loss of heterozygosity (LOH) on chromosome 11 is frequently altered in various epithelial cancers. The present study was designed to investigate LOH on chromosome 11 in microdissected samples of normal prostatic epithelium and invasive carcinoma from the same patients. For this purpose, DNA was extracted from the microdissected normal and tumor cells of 38 prostate cancers, amplified by polymerase chain reaction PCR and analyzed for LOH on chromosome 11 using 9 different polymorphic DNA markers (D11S1307, D11S989, D11S1313, D11S898, D11S940, D11S1818, D11S924, D11S1336 and D11S912). LOH on chromosome 11 was identified in 30 of 38 cases (78%) with at least one marker. Four distinct regions of loss detected were: 1) at 11p15, at loci between D11S1307 and D11S989; 2) at 11p12, on locus D11S131 (11p12); 3) at 11q22, on loci D11S898, D11S940 and D11S1818; and 4) at 11q23-24, on loci between D11S1336 and D11S912. We found 25% of the tumors with LOH at 11p15; 39% had LOH at 11p12; 66% had LOH at 11q22; and 47% had LOH at 11q23-24. These deletions at 11p15, 11p12, 11q22 and 11q23-24 loci were not related to the stage or grade of the tumor.

Expression and function of the complement membrane attack complex inhibitor protectin (CD59) in human prostate cancer

Protectin (CD59) inhibits homologous complement-mediated cytolysis by preventing formation of the membrane attack complex at the point of insertion and polymerization of C9 into cell membranes. The present study investigated the expression and function of CD59 on human prostatic tumor cells in situ and on 5 human prostate cell lines in vitro originating from either metastatic tumors or benign prostate hypertrophy epithelial cells. Immunohistochemical staining of prostate carcinoma tissue with monoclonal antibody (MAb) MEM43 revealed weak to moderately strong expression of CD59 by prostate glandular epithelial cells. Flow cytometry with MEM43 demonstrated that the 5 prostate cell lines expressed different relative quantities of CD59. Indirect immunofluorescence analysis revealed uniform membrane staining of DU145 and PC3 cell lines with no membranous granularity in the staining pattern. Western immunoblots with MAb BRIC 229 showed that PC3 and DU145 cells express CD59 with a m.w. of 18-25 kDa. Treatment of DU 145 and PC3 cells with phosphatidylinositol-specific phospholipase C caused a significant decrease of CD59 expression indicating that the CD59 expressed by prostate cancer cells is anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage. PC3 and DU145 cells were completely resistant to human complement-mediated cytolysis but became sensitive to killing in the presence of the CD59-neutralizing MAb YTH53.1. We conclude that malignant and benign human prostate cells express CD59 that is GPI-linked to the cell surface and that CD59 may regulate the immunological response to cancerous prostate cells by protecting the cells from the cytolytic activity of complement.

Effect of retinoic acid on prostatic development

BACKGROUND AND METHODS

To assess the effect of retinoids on prostatic ductal branching morphogenesis, anterior prostates from newborn rats were cultured under serum-free conditions for 6 days in the presence of testosterone (10(-8) mM) plus 13-cis-retinoic acid (13-cis-RA), all-trans-retinoic acid (at-RA), or N-4-hydroxyphenyl-retinamide (4-HPR). Measures of morphologic complexity were computed and compared between specimens of different treatment groups.

RESULTS

Prostatic ductal growth and branching were inhibited in a dose-dependent fashion by both 13-cis-RA and at-RA, but not by 4-HPR. This inhibitory effect of 13-cis-RA was reversible, as the prostatic ducts resumed branching and growth after removal of retinoic acid from the culture medium. Using reverse transcription polymerase chain reaction, we then investigated the expression of nuclear receptor genes for retinoic acid.

CONCLUSIONS

This showed the presence of RAR-beta and RAR-gamma in the 0-day prostate, suggesting that the effects of these retinoids on ductal morphogenesis may be via these receptors.

Mucins secreted by cell lines derived from colorectal mucinous carcinoma and adenocarcinoma

Mucinous (colloid) carcinoma and well- to moderately-differentiated adenocarcinoma of the colon differ in the pattern and the amount of mucin secretion and perhaps in their behaviour and clinical outcome. To ascertain why these differences exist and to elucidate the mechanisms of tumour progression, we examined two model human cell lines derived from colorectal mucinous carcinoma (C1a) and moderately differentiated adenocarcinoma (HM3) which show typical pathological and mucin staining patterns of the respective type of carcinomas to nude mouse tumour xenografts. Specifically, we sought to determine if there were quantitative and qualitative differences in mucin synthesis, in mucin gene expression and in biological properties between the two model cell lines. Northern blot analysis showed that MUC2 mRNA levels were significantly higher in C1a cells compared with HM3 cells, while those of MUC3, -5 and -6 mRNA were lower. C1a cells secreted approximately five times more radiolabelled apomucin and 1.5 times more glycosylated apomucin than HM3 cells. When the carbohydrate side-chain length of secreted mucins by these cell lines were examined by beta-elimination followed by P4 column chromatography, C1a mucins had mostly short carbohydrate side-chains, while HM3 cells had predominantly longer side-chains. Western blot analysis of the cell homogenate showed higher expression of MUC2 apomucin and mucin-associated carbohydrate antigens, such as T, Tn and sialyl Tn, with decreased sialyl Le(x) expression in C1a cells compared with HM3. Immunohistochemical analysis of 35 colorectal adenocarcinoma and 25 mucinous colorectal carcinoma tissues also demonstrated increased MUC2 apomucin, T, Tn and sialyl Tn antigens in the mucinous cancer specimens. Examination of the biological properties of these cell lines showed that C1a cells had significantly higher in vitro invasive activity in assays of invasion and collagenase activity and significantly lower E-selectin binding and liver colonisation activities in nude mice. These results indicate that colorectal mucinous carcinoma cells differ considerably from colorectal adenocarcinoma cells, both qualitatively and quantitatively, in the pattern of mucin gene expression and in the synthesis and secretion of mucin. In addition, biological studies showed that mucinous carcinoma cells have a greater degree of invasiveness, but less liver colonising activity. These results suggest that the biological and mucin characteristics of mucinous carcinoma cells contribute to extensive local invasion through tissue stroma as the predominant mechanism of tumour progression, while the biological and mucin characteristics of well- to moderately-differentiated colorectal adenocarcinoma contribute to progression via distant metastasis formation.

Reproduction of functional smooth muscle tissue and partial bladder replacement

OBJECTIVE

To find a means of bladder augmentation that would avoid the complications encountered with the use of bowel segments, using a newly developed acellular biomaterial, the bladder acellular matrix graft (BAMG), as a homologous graft.

MATERIALS AND METHODS

Thirty-four rats underwent a partial cystectomy (40-50%) and grafting with a BAMG of equal size. Eleven rats died within the first 72 h. probably from urinary leakage caused by obstruction of the bladder neck with stones or coagula; the surviving 23 were killed at varying intervals after cystectomy and examined.

RESULTS

After providing initial bladder enlargement, the graft was progressively infiltrated by the vessels and smooth muscle cells of the host: furthermore, the mucosal lining was complete within 10 days. After 4 weeks, all bladder wall components were evident histologically in the graft. The ingrowth was complete after 8 weeks, except for neural regeneration, which was only partial. At 12 weeks, the bladder wall muscle structure in the graft was so well developed that it was difficult to delineate the junction between host bladder and BAMG. Neural regeneration continued to improve. Normal bladder capacities were maintained throughout the study.

CONCLUSION

The BAMG appears to serve, without rejection, as a framework of collagen and elastin for the ingrowth of all bladder wall components. The reason for the better acceptance of the BAMG than of other bladder augmentation grafts requires further investigation.

Chromosome 3p24-26 and 3p22-12 loss in human prostatic adenocarcinoma

Identification of loss of heterozygosity on specific genetic loci is crucial for understanding the pathogenesis of prostate cancer at the molecular level. This is especially important because the deleted regions may contain putative tumor suppressor genes. Chromosome 3p loss appears to be frequently associated with various epithelial cancers. To our knowledge, there is no report on loss of heterozygosity (LOH) of chromosome 3 in human prostate cancer. The present study was designed to investigate the LOH on chromosome 3p in microdissected samples of delineated regions of normal and invasive carcinoma areas of prostatic epithelium from the same tumor sections. For this purpose, DNA was extracted from microdissected normal and tumor cells of 38 prostate cancers, amplified by PCR and analyzed for LOH on chromosome 3p using 6 different polymorphic DNA markers (D3S1560, THRB, D3S647, D3S1298, D3S1228 and D3S1296). Our results suggest that LOH was identified in 34 of 38 cases (89%) with at least one marker. Twelve of 30 informative cases showed LOH at D3S1560; 18 of 22 informative cases showed loss at THRB; 20 of 38 informative cases showed deletion at D3S647; 16 of 38 informative cases showed loss at D3S1298; 12 of 34 informative cases showed LOH at D3S1228; and 6 of 34 informative cases showed LOH at D3S1296 regions. Our results suggest that the LOH is on the 3p24-26 and 3p22-12 regions of the short arm of chromosome 3, indicating 2 discrete areas of deletion on chromosome 3p. The deletion at 3p24-26 and 3p22-12 was not related to the stage or grade of the tumor.

Induction of cyclo-oxygenase-2 mRNA by prostaglandin E2 in human prostatic carcinoma cells

Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations.

Differential gene expression of transforming growth factors alpha and beta, epidermal growth factor, keratinocyte growth factor, and their receptors in fetal and adult human prostatic tissues and cancer cell lines

OBJECTIVES

Recent studies have shown that growth factors may play a role in the etiology of benign prostatic hyperplasia (BPH) and prostatic carcinoma. Several growth factors have been reported to be expressed by prostatic tissues, but these growth factors have never been examined in human fetal prostate and compared with adult prostates and cancer cell lines. The present study was designed to investigate the messenger ribonucleic acid (mRNA) expression of transforming growth factor (TGF)-alpha, TGF-beta 1, TGF-beta 2, TGF- beta 3, keratinocyte growth factor (KGF), epidermal growth factor (EGF), EGF receptor (EGF-R), and KGF receptor (KGF-R) in human fetal and adult prostatic tissues and cancer cell lines by reverse-transcriptase-polymerase chain reaction-(RT-PCR) using specific oligonucleotide primers.

METHODS

Total RNA was extracted from human fetal and adult prostates (BPH tissues) and cancer cell lines. The gene expression of these growth factors and their receptors was determined by RT-PCR using specific oligonucleotide primers.

RESULTS

The results of these experiments suggest that: (1) human fetal prostate expressed mRNA transcripts for TGF-alpha, TGF-beta 1, TGF-beta 2, TGF-beta 3, and EGF. However, KGF, KGF-R, and EGF-R mRNA were not expressed by human fetal prostate; (2) human adult prostate (BPH tissues) showed mRNA transcripts for all growth factors and their receptors except KGF-R; (3) human BPH-1 cell lines expressed mRNA transcripts for TGF-alpha, TGF-beta 1, TGF-beta 2, TGF-beta 3, EGF, and KGF-R, but not for EGF-R and KGF growth factors; (4) human primary prostate cancer cell line (ND-1) showed mRNA transcripts for all growth factors except EGF and KGF; and (5) human prostate cancer cell lines (LNCaP, DU-145, PC-3) expressed mRNA transcripts for all growth factors except KGF, which was absent in all cell lines. However, KGF-R mRNA was absent in the PC-3 prostate cancer cell line.

CONCLUSIONS

These results suggest that the differential gene expression for various growth factors and their receptors in human fetal and adult prostatic tissues and cancer cell lines may be important in understanding the role of these factors in the pathophysiology of prostatic diseases.

Effect of thermal variables on frozen human primary prostatic adenocarcinoma cells

OBJECTIVES

Recent advances in imaging technology and cryotechnology have rekindled interest in prostate cryosurgery. Cryosurgery, however, cannot be applied precisely without knowing how the thermal variables used during the procedure affect tissue destruction. The goal of this article is to provide quantitative values for the relationship between thermal variables during freezing and the destruction of human primary prostatic adenocarcinoma cells.

METHODS

Human primary prostatic adenocarcinoma cells were frozen with controlled thermal parameters, using a directional solidification apparatus. Cell viability was determined after thawing, using trypan blue and a two-dye fluorescent test and correlated to the thermal variables used during freezing.

RESULTS

Human primary prostatic adenocarcinoma cells are damaged by intracellular chemical damage when frozen with cooling rates lower than 5 degrees C/min and by intracellular ice formation when frozen with cooling rates higher than 25 degrees C/min. A double freeze/thaw cycle is required to ensure complete cell destruction at high subzero temperatures, which must be lower than -40 degrees C for the low cooling rates and lower than -19 degrees C for the higher cooling rate.

CONCLUSIONS

Haphazard freezing does not necessarily destroy tissue during cryosurgery; however, quantitative data on the relation between thermal variables and frozen cell destruction can provide the means for performing cryosurgery more precisely and with greater control over the outcome of the procedure.

P53 tumour-suppressor gene mutations are mainly localised on exon 7 in human primary and metastatic prostate cancer

Mutations in the p53 tumour-suppressor gene are among the most common genetic alterations in human cancers. In the present study we analysed the mutations in the p53 tumor-suppressor gene in 25 primary and 20 metastatic human prostate cancer specimens. DNA extracted from the paraffin-embedded sections was amplified by hot-start polymerase chain reaction, and p53 gene mutations in the conserved mid-region (exons 4-9) were examined using single-strand conformation polymorphism (SSCP) analysis and immunohistochemistry. In the present study, we used a novel hot-start PCR-SSCP technique using DNA Taq polymerase antibody, which eliminates primer-dimers and non-specific products. Because of this new technique, the results of PCR-SSCP showed very high resolution. Polymerase chain reaction products were sequenced directly for point mutations for the p53 gene. Mutations were found in 2 out of 25 primary prostate cancers (8%) and 4 out of 20 metastatic cancers (20%). Mutations were observed exclusively in exon 7 and not in exons 4, 5, 6, 8 or 9. Nuclear accumulation of p53 protein, determined by immunohistochemistry, correlated with the degree of metastasis in prostatic cancer.

Inhibitory effects of retinoic acids on androgen-dependent development of neonatal mouse seminal vesicles in vitro

The effects of retinoic acids (RAs) on development of seminal vesicles (SVs) of neonatal mice were investigated in vitro. SVs from 0-day-old male mice were cultured for 2-6 days in serum-free, chemically defined medium containing transferrin and BSA supplemented with 5alpha-dihydrotestosterone (DHT; 10(-8) M) and insulin (10 microg/ml), alone and in combination. Before culture, SVs from 0-day-old mice consisted of an unbranched epithelium surrounded by mesenchyme. SVs cultured in medium with DHT plus insulin or DHT alone formed numerous epithelial branches after day 2 of culture, whereas epithelial branching did not occur in SVs cultured with insulin alone. All-trans-RA or 13-cis-RA (10(-9)-10(-6) M) added to medium containing DHT plus insulin or DHT alone inhibited epithelial branching in a dose-dependent manner. This inhibitory effect was reversible after removal of the retinoids from the medium on day 4 of culture. These RAs also decreased [3H]thymidine labeling indexes of both epithelium and mesenchyme of SVs cultured in medium with DHT plus insulin or DHT alone and inhibited the increase in their protein contents. 9-Cis-RA was less inhibitory than all-trans-RA or 13-cis-RA on epithelial branching, [3H]thymidine labeling indexes of epithelium and mesenchyme, and protein content of SVs cultured in medium with DHT and insulin. In the absence of DHT (insulin alone), all-trans-RA did not affect either the [3H]thymidine labeling indexes of epithelium and mesenchyme or the protein content of cultured SVs. Reverse transcriptase-PCR demonstrated strong expression of transcripts for mouse RA receptors (RARalpha, RARgamma, and RXRalpha), with lower levels of expression of RARbeta, RXRbeta, and RXRgamma in neonatal SVs. The present results indicate that RAs reversibly inhibit androgen-dependent development of neonatal mouse SVs, most likely through RARs.

Epithelial development in the rat ventral prostate, anterior prostate and seminal vesicle

The prostate and seminal vesicle (SV) are androgen-dependent secretory glands of the male genital tract. The epithelial cells of these glands produce the bulk of the seminal secretions. The objective of the present study was to examine the ontogeny of cytokeratin and androgen receptor (AR) expression in the rat SV, anterior prostate (AP) and ventral prostate (VP). The study utilized organ culture to examine the effects of androgens on the development of these markers and castration of adult rats to examine androgenic effects on their maintenance. Tissues were examined from 14 days of gestation to adulthood. The SV was a tubular organ from its inception while the prostate formed from solid epithelial cords. These prostatic buds canalized in a proximal to distal manner starting at day 1 postnatal in the VP and day 5 in the AP. The expression of cytokeratins and AR was visualized by immunocytochemistry. In all three glands keratins 5, 7, 8, 14, 18 and 19 were initially uniformly expressed in all epithelial cells. In the SV, segregation of cytokeratins between the luminal and basal cell types started at 4 days postnatally with keratin 7 localizing to basal cells. Five days after birth, keratins 5 and 14 were also localized to the basal epithelium, while keratins 8 and 18 were only expressed by luminal cells, Keratin 19 was expressed in all epithelial cells throughout development and into adulthood. In the VP and AP the same pattern of cytokeratin segregation occurred as in the SV. Epithelial differentiation occurred in a proximal to distal fashion in the prostate. In the proximal VP ducts keratins 7 and 14 were basally localized by 2 days postnatally, while keratin 5 did not clearly segregate to basal cells until day 9 after birth. In the AP keratin 14 was basally localized by 1 day postnatal but keratin 5 and 7 did not colocalize to the basal cells until days 9 and 12, respectively. AR were expressed in the epithelium of the urogenital sinus from 19 days of gestation. At 19 and 20 days of embryonic development AR-negative prostatic buds were seen emerging from the AR-positive urogenital sinus epithelium. By birth AR were detectable in the epithelium of both prostatic lobes and the SV. The role of androgens in the development of the prostatic and SV epithelium was investigated in a serum-free organ culture system. These experiments showed that differentiation of prostatic and SV luminal and basal epithelial cell types was accelerated as compared to the in vivo situation in the presence of androgens, and did not occur in their absence. Following castration of adult animals the prostate and SV regressed with preferential loss of luminal epithelium. The relative numbers of basal cells was increased, though some flattened cells expressing a luminal cell pattern of cytokeratins were still observed. AR were detected in the prostatic and SV epithelium of long-term castrated animals. In summary, the rat prostate was found to be derived from undifferentiated solid epithelial cords. Canalization occurred concurrent with the differentiation of clear epithelial subtypes. Epithelial AR were expressed from around the time of birth and expression levels increased with age. The SV was canalized from its inception but likewise was derived from an undifferentiated epithelial precursor.

Smooth muscle-epithelial interactions in normal and neoplastic prostatic development

A hypothesis is proposed that unifies prostatic developmental biology and carcinogenesis. The foundation of this hypothesis is the reciprocal interaction of epithelium and mesenchyme during prostatic development followed thereafter by a reciprocal homeostatic interaction of epithelium and smooth muscle in adulthood. This smooth muscle-epithelial cell interaction is perturbed during prostatic carcinogenesis with adverse sequelae for both epithelium and smooth muscle. The following sequence of events is proposed to occur: (1) Under the influence of androgens, urogenital sinus mesenchyme (UGM) induces urogenital sinus epithelium to undergo prostatic ductal morphogenesis and differentiation. (2) As prostatic epithelium differentiates, it in turn signals the UGM to differentiate into smooth muscle cells that closely surround the epithelial ducts. Differentiation of prostatic smooth muscle requires both an inductive signal from epithelium and androgens. (3) Once formed, prostatic smooth muscle participates in reciprocal homeostatic interactions. We propose that prostatic smooth muscle under the influence of androgens signals to prostatic epithelium to maintain epithelial differentiation and to repress epithelial proliferation, while prostatic epithelium signals to prostatic smooth muscle to maintain smooth muscle differentiation. In adulthood, homeostasis is maintained through reciprocal interactions between smooth muscle and epithelial cells with minimal proliferation of either cell type. Prostatic carcinogenesis, which is initiated following genetic damage to prostatic epithelium, is surmised to involve a sequential disruption in these reciprocal homeostatic interactions with ensuing dedifferentiation of both the emerging prostatic carcinoma cells and smooth muscle. Thus, following genetic insult to prostatic epithelium the epithelium fails to signal appropriately to the smooth muscle, which then begins to dedifferentiate. As smooth muscle differentiation begins to deviate, signaling from prostatic smooth muscle to prostatic epithelium becomes anomalous resulting in progressive loss of control over epithelial differentiation and proliferation. During progression of prostatic carcinogenesis a vicious cycle is established in which both prostatic epithelium and smooth muscle dedifferentiate. This hypothesis is based on the ontogeny of prostatic smooth muscle differentiation during development and by the fact that the amount of smooth muscle progressively diminishes in human prostatic adenocarcinomas during progression from low- to high-grade cancers. Finally, in experimental tissue recombinants in which various normal or neoplastic prostatic epithelia were grown in combination with embryonic rat UGM, only normal (non-neoplastic) epithelia were capable of inducing differentiation of prostatic smooth muscle in UGM. Based on several lines of evidence, it is now apparent that smooth muscle-epithelial interactions are the operative cell-cell interaction in the postnatal prostate which plays a key role in regulating epithelial differentiation, proliferation and carcinogenesis.