Microsatellite alterations and loss of heterozygosity in Peyronie's disease

PURPOSE

In the present study, we tested the hypothesis that microsatellite alterations (MSI) and loss of heterozygosity (LOH) are associated with Peyronie's disease. To test this hypothesis, we analyzed samples from patients with Peyronie's for MSI and LOH on chromosomes 3, 8 and 9 using 20 different genetic markers.

MATERIALS AND METHODS

DNA was isolated from the penile fibrotic plaque, amplified using PCR, and analyzed for MSI and LOH on chromosomes 3, 8 and 9 using 20 different polymorphic markers (D3S1228, D3S1298, D3S1560, D3S1745, D3S2396, D3S647, D8S133, D8S255, D8S259, D8S260, D8S262, D8S285, D8S298, D8S507, D8S528, D9S162, D9S171, D9S1747, D9S1748, and D9S273). Only 10 primers (D3S1560, D3S647, D3S1298, D8S262, D8S260, D8S528, D9S171, D9S1747, D9S273 and D9S1748) showed MSI and LOH in Peyronie's samples. Microsatellite alterations and LOH were analyzed by a PCR-based technique developed in our laboratory.

RESULTS

This study demonstrates a high frequency of MSI and LOH in Peyronie's disease. Fourteen of 35 cases (40%) showed MSI at a minimum of one locus, 6 of 35 cases (17%) at a minimum of 2 loci and three of 35 (8.5%) cases at three or more loci. D9S273 locus showed highest MSI when compared with other loci examined in this study. For LOH, 14 of 35 cases (40%) were observed at a minimum of one locus, 5 of 35 cases (14%) at minimum of two loci and one out of 35 cases (2.8%) showed LOH at three or more loci. The D3S1560 and D9S171 loci showed highest LOH when compared with all other loci examined in this study.

CONCLUSION

This is the first report demonstrating that a high frequency of MSI and LOH is associated with Peyronie's disease, suggesting their role in the pathogenesis of this disease.

Cloning and characterization of human estrogen receptor beta promoter

Estrogen receptors beta (ERbeta) belong to the nuclear receptor superfamily of ligand-dependent transcription factors that play critical roles in regulating genes involved in a wide array of biological processes. To investigate regulation of tissue-specific expression of ERbeta, we cloned and characterized a 2.1-kilobase 5'-flanking region of the human ERbeta gene. Two major transcription start sites were identified by primer extension and rapid amplification of 5'-cDNA end. The human ERbeta proximal promoter contains both TATA box and initiator element (Inr) and is GC-rich with a GC content of 65%. An Alu repeat sequence containing an ER-dependent transcription enhancer exists between -1416 and -1703. The full-length 5'-flanking sequence of ERbeta fused to a luciferase reporter exhibited functional promoter activity in ERbeta-positive TSUPr1 cell, but not in ERbeta-negative DU145 cells. In addition, DNase I protection assays of the proximal promoter showed unique protection patterns with nuclear extracts from TSUPr1 cells and ERbeta negative HeLa cells, suggesting presence of cell-specific trans-acting factors that mediate tissue/cell-specific ERbeta expression. Serial deletion analysis revealed that a 293-bp region encompassing the TATA box and Inr element possesses basal promoter activity.

Bladder acellular matrix graft in rats: its neurophysiologic properties and mRNA expression of growth factors TGF-alpha and TGF-beta

To assess the neurophysiologic properties and molecular mechanisms of the bladder acellular matrix graft (BAMG), we performed cystometric and neurophysiologic studies in male Sprague-Dawley rats (n = 46) at varying intervals. The animals were assigned to 3 groups: 1) normal, 2) partial cystectomy (>50%), and 3) partial cystectomy (>50%) and grafting with a BAMG of equal size. Additionally, matrix-grafted and host bladders were processed for analysis of mRNA expression of transforming growth factor (TGF)-alpha, TGF-beta1, TGF-beta2, and TGF-beta3 by reverse transcriptase polymerase chain reaction. Matrix-grafted bladders showed a significantly higher bladder capacity at 3 and 6 weeks and 4 months than those with partial cystectomy alone, and a significantly higher bladder capacity at 4 months than in normal controls (P < or = 0.01). Residual urine volume was significantly increased at 4 months. Electrostimulation of the pelvic nerve provoked generalized bladder contractions, a response that was reduced by atropine and hexamethonium. Variable induction of TGF-alpha, TGF-beta1, TGF-beta2, and TGF-beta3 gene transcription was evident in the BAMG, with prominent mRNA expression of TGF-alpha and TGF-beta1 6 months after surgery. These cystometric results and detrusor responses to stimulation provide further evidence that graft components do not interfere with host components. Matrix-grafted rat bladders generate, although not increased over time, adequate intravesical pressure responses to produce sustained voiding. Gene expression of different growth factors may be significant in understanding their role in the development and differentiation of the BAMG for partial bladder replacement.

Microsatellite instability of dinucleotide tandem repeat sequences is higher than trinucleotide, tetranucleotide and pentanucleotide repeat sequences in prostate cancer

In order to investigate whether the change in length of simple repetitive genomic sequences (microsatellite instability) is associated with prostate cancer, we analyzed 40 prostate cancer samples with 44 microsatellite loci markers on chromosomes 1, 3, 5, 6, 8, 9, 11, 13, 16, 17 and X. DNA was extracted from normal and tumor cells of 40 microdissected cancer samples, amplified by PCR and analyzed for microsatellite instability using 44 primers for dinucleotide, trinucleotide, tetranucleotide and pentanucleotide repeat sequences. The results of this study demonstrate that 45% of the prostate cancer specimens (18 out of 40) showed microsatellite instability (MSI) at a minimum of one locus using dinucleotide repeat sequences. Two out of 40 samples (5%) showed MSI at a minimum of one locus using three different trinucleotide repeat primers (AR, SR and TBP). Ten out of 40 (25%) samples showed MSI at a minimum of one locus using five different tetranucleotide repeat primers (HPRT1, HPRTII, MYCL1, RB, REN). There were no MSI observed in samples using pentanucleotide repeat sequences. There were no MSI in benign prostatic hyperplasia samples (25 samples). These experiments suggest that the microsatellite instability of dinucleotide tandem repeat sequences is much higher than trinucleotide, tetranucleotide and pentanucleotide repeat sequences in prostate cancer. The MSI with different lengths of nucleotide repeat sequences did not correlate with the stage and grades of prostate cancer.

Homologous acellular matrix graft for urethral reconstruction in the rabbit: histological and functional evaluation

OBJECTIVE

To evaluate urethral replacement by a free homologous graft of acellular urethral matrix in a rabbit model.

MATERIALS AND METHODS

In 30 male New Zealand rabbits, a 0.8 to 1.1 cm. segment of the urethra was resected, replaced with an acellular matrix graft of 1.0 to 1.5 cm. (mean 1.3 cm.), and placed on an 8F feeding tube. Additionally 4 animals underwent sham operation. At varying intervals before sacrifice (from 10 days to 8 months), the animals underwent urodynamic evaluation and retrograde urethrography (for which 4 untreated rabbits served as control). The grafted specimens were prepared for evaluation histologically and by reverse-transcription polymerase chain reaction (RT-PCR).

RESULTS

In all animals, the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 3 months, smooth muscle bundles were first observed infiltrating the matrix at the end-to-end anastomosis; after 6 months, the smooth muscle bundles had grown into one-third of the matrix. Urodynamics did not detect any difference between the control and matrix-grafted animals in bladder volume, leak-point pressure and residual volume. RT-PCR detected an increase in IGF mRNA in the graft between week 3 and month 6 and in HB-EGF mRNA after day 10 through month 3. TGF-alpha mRNA was not detected; TGF-beta mRNA was unchanged from normal urethral tissue. By 8 months, the host and implant could not be differentiated by urethrography.

CONCLUSION

The acellular urethral matrix allows single-stage urethral reconstruction. All tissue components were seen in the grafted matrix after 3 months, with further improvement over time; however, the smooth muscle in the matrix was less than in normal rabbit urethra and was not well oriented. RT-PCR revealed the importance of time-dependent growth factor influences during regeneration.

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.