Molecular urology最新文献

Although serum prostate specific antigen (PSA), derived from cellular PSA through secretion, is widely used as a marker for prostate cancer (CAP), the exact regulatory mechanism of its secretion is not fully understood. To explore the regulation of serum PSA concentration, we examined whether the glycosylation state of cellular PSA might be associated with its secretion, thus determining its serum concentration. Blood and prostate tissue specimens were obtained from patients undergoing radical prostatectomy. Following preparation of cell extracts by tissue homogenization, the concentrations of serum and cellular PSA were determined using the Tandem-E PSA kit. The extent of cellular PSA glycosylation was then assessed by Western blot and affinoblott analyses. Neither serum nor cellular PSA concentrations correlated with the Gleason scores. Similarly, no direct relation between serum and cellular PSA levels was observed. However, the Western blots showed that the cellular PSA proteins were converted to the deglycosylated forms with glycosidase treatment, indicating differential glycosylation of cellular PSA. Affinoblotting further revealed that the various amounts of PSA glycosylation were associated wtih the serum PSA levels, with an inverse correlation between serum PSA and cellular PSA glycosylation: the greater the PSA glycosylation, the lower the serum PSA, and vice versa. The present study demonstrates that cellular PSAs in CAP specimens are differentially glycosylated and that such difference correlates well with the serum PSA concentration. Therefore, the concentrations of serum PSA appear to depend in part on a selective secretion of cellular PSA, which could be regulated primarily by its glycosylation state.

Recently, we developed a novel molecular approach, CD44 v8-10/CD44 v10 competitive reverse transcription-polymerase chain reaction (CC-RT-PCR), to detect a sparse population of cancer cells overexpressing CD44v8-10 among a much larger population of nonneoplastic cells in body fluids by the measurement of the transcriptional level of CD44v8-10 relative to that of CD44v10. We have shown the utility of CC-RT-PCR in diagnosing disease using urine samples from patients with bladder cancer. In this study, we initially examined the expression of CD44 splice variants in human upper urinary tract transitional-cell carcinomas (UUT-TCCs) and their adjacent normal urinary tissues by RT-PCR. Any CD44 variant isoforms were barely detectable in normal urinary tissues, whereas CD44v8-10 was predominantly expressed in 21 of the 25 UUT-TCC specimens (84%). We then applied CC-RT-PCR to spontaneously voided urine samples from 40 patients with UUT-TCC and 40 patients with benign urologic diseases. The CC-RT-PCR analysis revealed that all of the samples from patients with benign diseases presented a predominant expression of the CD44v10 transcript, whereas 26 of the 40 samples from patients with UUT-TCC dominantly expressed the CD44v8-10 transcript. In addition, the positive rate obtained by the CC-RT-PCR analysis was significantly higher than that obtained by cytologic examination, especially in patients with low-grade UUT-TCC. These findings strongly suggest that CC-RT-PCR is a useful noninvasive tool for the diagnosis of UUT-TCC.

Neoadjuvant hormonal therapy (NHT) has been extensively studied in patients undergoing radical prostatectomy and external-beam irradiation for prostate cancer. While there are a few reports in the literature on its use in men undergoing brachytherapy, little information exists about its beneficial effects in such patients. In this report, we describe the effects of NHT on prostate volume (PV) prior to seed implantation and on the prostate specific antigen (PSA) and postimplant biopsy outcomes of patients who presented with high-risk features. Hormone therapy (leuprolide and flutamide 750 mg/day) was given to 145 patients for 3 months prior to and for 3 months after permanent iodine-125 (160 Gy) or palladium-103 (115 Gy) seed implantation. Of these, 28 (19%) received NHT because of a preimplant PV >50 cc, and 117 patients received NHT because they had a PSA >10 ng/mL, Gleason score >/=7, or clinical stage >/=T(2b). All patients underwent implantation using the real-time intraoperative method, and no patients received external-beam irradiation. Of the 145 patients treated, 67 (46%) had a PSA >10 ng/mL (range 1.9-57 ng/mL; mean 12.2 ng/mL), 50 (35%) had Gleason score >/=7, and 80 (55%) had stage >/=T(2b) disease. Prostate volume was measured in 106 patients prior to NHT and 3 months later immediately prior to the seed implant. The mean PV was 50.4 cc (range 17-150 cc), whereas the mean PV after NHT was 31 cc (range 11.7-73.7 cc). The mean PV reduction was 35% (range 2%-62%). Volume reduction was compared in those patients who presented with a PV <40 cc (N = 51) and those with a PV >/=40 cc (N = 56). The mean reduction for the smaller glands was 29% (range 2%-54%) compared with 41% (range 7%-62%) for the larger glands (P < 0.05). Patients were followed for a minimum of 1 year (range 1.0-6.4; mean 2.2 years). The 4-year actuarial rate of freedom from PSA failure (PSA >1.0 ng/mL with two consecutive elevations) was 85%. There was no difference in rates of freedom from PSA failure for those with initial Gleason 2-4 (96%), 5-6 (78%), 7 (80%), or 8-9 (83%; P = 0.5). Control rates were 85% for patients with PSA 20 ng/mL (P = 0.8). There was a trend to decreased control rates with higher-stage disease (98% for T(1)-T(2a) v 68% for T(2c)), but these differences were likewise not significant (P = 0.12). The control rates for the 28 low-risk patients with enlarged prostate glands were compared with those of the 117 with high-risk features and were not different (100% v 82%; P = 0.1). There were 62 patients who agreed to eight-core prostate biopsies 2 years after implantation, and 60 (97%) were negative for tumor. This trial shows that NHT can reduce PV an average of 35% prior to seed implantation with the greatest reduction found in patients with larger prostates (41%). Hormonal therapy also appears to improve biochemical (PSA) control and local control (prostate biopsy

Since the discovery that nitric oxide is the mediator of penile erection, considerable evidence has been accumulated in experimental animals and men regarding the pharmacology and molecular biology of the nitric oxide/cGMP pathway in the penis. This review examines the expression and tissue localization of nitric oxide synthase isoforms (NOS) in this organ and the functional significance of their variants. The disregulation of the balance between nitric oxide synthesis and the compliance of the corpora cavernosa smooth muscle in relation to erectile dysfunction in animal models is discussed. The possible up-regulation of NOS levels and the interaction of NOS variants with protein modulators of their activity is analyzed in the context of novel concepts of gene therapy of erectile dysfunction.

This report reviews the long-term follow-up of a prospective Phase II evaluation of intermittent androgen suppression in the treatment of prostate cancer. A total of 87 patients have been entered in this protocol. At the time of this report, 50 men have been followed for a minimum of 3 years. Treatment was initiated with combined androgen blockade and continued for at least 6 months until a serum PSA nadir was observed. Medication was then withheld until the serum PSA increased to mean values between 10 and 20 ng/mL. This cycle of treatment and no treatment was repeated until the regulation of PSA became androgen independent. The total time in the study ranges from 40 to 126 months, with a mean of 65.5 months. The off-treatment period in the first cycle for the men with long-term follow-up was associated with an improvement in the sense of well-being and recovery of libido and potency in men who reported normal or near-normal sexual function before the start of therapy. The average time off therapy (percentage time off therapy) for cycles 1, 2, 3, and 4 was 15 months (54%), 10 months (48%), 8 months (45%), and 7 months (40%), respectively. The study group included 9 patients treated because of a rising PSA concentration after radiation therapy for locally advanced cancer. These patients have been off therapy for an average of 22 and 13 months in treatment cycles 1 and 2, respectively. Six patients with rising PSA values after radical prostatectomy and with follow-up exceeding 36 months have been off therapy for an average of 19 and 11 months in treatment cycles 1 and 2, respectively. Of the 87 patients, 23 have had their disease progress to androgen independence at a median of 32 months of treatment, and 13 have died cancer-specific deaths at a median of 48 months. Prostate cancer is amenable to control by intermittent androgen suppression. This approach affords an improved quality of life when the patient is off therapy, with reduced toxicity and costs. Phase II trials suggest that there is not a negative impact on patient outcome. Randomized protocols are currently in progress to determine whether survival is affected in a beneficial or adverse way by such treatment in men with locally recurrent or metastatic cancer.

Spectrum analysis of radiofrequency (RF) ultrasonic echo signals often can sense tissue differences that are not visible on conventional ultrasonic images. Spectrum-analysis parameter values combined with other variables, such as serum prostate specific antigen (PSA) concentration, can be classified by neural networks to distinguish effectively between cancerous and noncancerous prostate tissues. Images based on neural network classification of spectral parameters and clinical variables can be advantageous for biopsy guidance, staging, and treatment planning and monitoring. A study based on 644 biopsies from 137 patients showed that these methods are significantly superior to B-mode image interpretation for differentiating cancerous from noncancerous prostate tissues. Using the histologic determination of tissue types as the gold standard, the area under the receiver-operator characteristic (ROC) curve for neural network classification based on spectrum analysis and PSA value for the 644 biopsies was 0.87 +/- 0.04, and the ROC curve are for a level-of-suspicion (LOS) assignment based on B-mode imaging was 0.64 +/- 0.04. Color-encoded and gray-scale images derived from neural network assignment of suspicion for cancer at each pixel location showed remarkable detail and suggested potential clinical value for biopsy guidance using real-time two-dimensional (2D) images and staging, treatment planning, and monitoring using three-dimensional (3D) images.

Renal oncocytomas are characterized by bland-appearing eosinophilic cells with a profusion of mitochondria. Previous work has suggested that these tumors possess a mutation in the 16.5-kbp circular mitochondrial DNA (mtDNA) manifested by an abnormal restriction fragment pattern after digestion with HinfI (Welter et al, Genes Chromosomes Cancer 1989;1:7-82). To better characterize this mtDNA abnormality in renal oncocytomas, we amplified the entire mitochondrial genome from five paired normal and oncocytoma specimens and subjected the amplified fragments to digestion with the restriction enzyme HinfI. No somatically acquired alterations were detected in the mtDNA from any of the five renal oncocytomas. One specimen displayed a known HinfI polymorphism in the mtDNA from both the normal and oncocytoma tissues. Our data do not support the existence of somatically acquired mitochondrial genome abnormalities in renal oncocytomas.

There is compelling experimental and clinical evidence that for adequate sexual function, there must be complex and efficient cross-communication between the endocrine and nervous systems, both centrally and peripherally. The central nervous system (CNS) controls the release of sex steroids, while at the same time, these hormones are primary modulators of neurologic activity. The investigation and treatment of men suspected of hypogonadism is simple, but careful monitoring is essential. Unfortunately, sexual dysfunction is frequently multifactorial, and in many patients, the dysfunction does not improve with hormonal replacement. However, hypotestosteronemia is associated with a variety of alterations in different organ systems beyond sexual activity. It is important to the practice of urology to be familiar with neuroendocrine interactions and to maintain an adequate knowledge of the evaluation and treatment of hormonal deficiencies, particularly in men beyond middle age, in whom hypogonadism is prevalent.

Sildenafil has had a revolutionary impact on the medical, societal, and economic aspects of erectile dysfunction. The author reviews the clinical trial and field experience with respect to the efficacy and safety of this drug. It is clear that early in the new millenium, erectile dysfunction will not only be effectively treated, it may even be prevented.

Recent studies indicate that localized (regional) ischemia may play an important role in the etiology of the contractile dysfunctions secondary to partial outlet obstruction. Pretreatment with Tadenan® (Pygeum africanum extract) has been shown to protect the rabbit bladder against the development of both contractile and biochemical dysfunctions induced by partial outlet obstruction, possibly by protecting the bladder against ischemic injury. The current study was designed to determine if Tadenan pretreatment of rabbits protected the bladder against the development of contractile dysfunctions induced by unilateral ischemia and to correlate effects in the presence and absence of Tadenan with the molecular response in relation to two of the most prominent genes activated by both ischemia and partial outlet obstruction: Hsp-70 and c-myc. Male New Zealand rabbits were separated into four groups of six rabbits each. Three rabbits of each group were treated for 3 weeks with Tadenan. The other three rabbits of each group were untreated controls. Each rabbit in Groups 2, 3, and 4 was anesthetized, and all major arteries entering on the right side of the bladder were li-gated. Rabbits in Group 1 were nonischemic. After 30, 60, and 120 minutes of unilateral ischemia, the rabbits in groups 2, 3, and 4, respectively, were euthanized. The bladders were removed, and contractility studies were performed on strips of detrusor muscle isolated from both the ischemia and nonischemic sides. The balance of the ischemic and nonischemic sides were frozen and stored in liquid nitrogen until analyzed for the expression of Hsp-70 and for c-myc. Tadenan pretreatment protected the nonischemic side of the bladder from the development of contractile dysfunctions, and unilateral ischemia resulted in a 10-fold increase in the expression of both Hsp-70 and c-myc in the bladders isolated from the Tadenan-treated rabbits. These results indicate that Tadenan has a protective effect against ischemic damage to the bladder. This protection may involve enhanced expression of Hsp-70 and other genetic factors.