Association of vitamin D receptors with the nuclear matrix of human and rat genitourinary tissues.

Calcitrol, 1,25 dihydroxyvitamin D3 (1,25-D3) has an important role in the antiproliferative and growth regulatory effects on normal and neoplastic cells (e.g. prostate cancer cells). 1,25-D3 binds to the vitamin D receptor (VDR), a member of the steroid receptor superfamily. Steroids, via intranuclear receptors, have been demonstrated to have high affinity binding to the nuclear matrix, the tissue specific scaffolding of the nucleus that is involved in the organization of DNA, replication and transcription. We hypothesized that the VDR interacts closely with the nuclear matrix in both human and rat tissues. In the studies described here, nuclear matrix proteins (NMP) were extracted from a number of rat and human tissues and immunoblot analysis performed using a rat anti-VDR antibody. The results from these studies reveal that the anti-VDR antibody detects six forms of the VDR in the NMP preparations: human testis demonstrated a protein of 57 and 52 kDa molecular weight compared with 57 and 37 kDa in the rat testis. Human prostate demonstrated proteins of 52 kDa compared to rat ventral (57 and 37 kDa) and dorsal prostate (52 and 26 kDa). Human and rat bladder NMP demonstrated a protein binding at 55 kDa and rat seminal vesicle NMP binding at 48 kDa. This is the first report of VDRs associated with the nuclear matrix. The varying molecular weight proteins reactive with the anti-VDR antibody within these tissues may represent different isoforms, proteolytic cleavage of a larger VDR or post-translational modification. The VDR-NMP interaction may be involved in the tissue specific actions of 1,25-D3 especially growth regulatory and antiproliferative effects.

Perineural invasion in transitional cell carcinoma and the effect on prognosis following radical cystectomy.

OBJECTIVES: The relationship between perineural invasion and prognosis has been demonstrated to be poor in a number of malignancies. This has not been evaluated in the bladder. We performed a study to determine the occurrence of nodal metastases, extranodal metastases, and disease-free survival in patients with perineural invasion (PNI) and/or angiolymphatic invasion (ALI) in transitional cell carcinoma of the bladder (TCCB) from radical cystectomy specimens. METHODS: A retrospective review of 27 patients treated with radical cystectomy for TCCB was conducted. Comparisons were performed between three groups: PNI with or without ALI (PNI +/- ALI, 12 patients), ALI alone (8 patients), and a control group (no PNI or ALI) (7 patients). RESULTS: The mean patient age was 70 years (range 49 to 83). The overall median follow-up period was 11 months (range 1 to 32). PNI +/- ALI was predominantly found in Stage T3b disease (14 of 20 [70%] cases). The overall 1-year disease-free survival was 48%, 67%, and 83% for the PNI +/- ALI, ALI alone, and control groups, respectively. Nodal metastases (for all stages combined) were found in 6 of 12 (50%), 3 of 8 (38%), and 1 of 7 (14%) patients in the PNI +/- ALI, ALI alone, and control groups, respectively. Similarly, extranodal metastatic disease was found in 5 of 12 (42%), 4 of 8 (50%), and 1 of 7 (14%) patients in the PNI +/- ALI, ALI alone, and control groups, respectively. The percentage of deaths for the PNI +/- ALI, ALI only, and control groups were 33%, 50%, and 14%, respectively. CONCLUSIONS: In TCCB, perineural invasion with or without angiolymphatic invasion and angiolymphatic invasion alone are associated with a higher incidence of nodal and extranodal metastases and death.

Vitamin D inhibition of prostate adenocarcinoma growth and metastasis in the Dunning rat prostate model system.

OBJECTIVES: Risk factors for prostate cancer (PCa)-related mortality include old age, black race, and residence in northern latitudes. The objectives of this study are to examine the in vitro and in vivo effects of 1,25-dihydroxycholecalciferol (1,25-D3) and less-hypercalcemic analogues on the Dunning rat prostate adenocarcinoma model. METHODS: To evaluate the effect of 1,25-D3 on PCa in vitro, we used the highly metastatic Mat-lylu (MLL) and moderately metastatic R3327-AT-2 (AT-2) Dunning prostate cell lines, and examined effects on growth, clonogenicity, differentiation, and cell cycle. In vivo analysis included examination of the effects of these compounds on tumor growth and metastasis. RESULTS: Using both the 3-day MTT and 7-day clonogenic assay, 1,25-D3 demonstrated a growth inhibitory effect with a concentration for 50% inhibition (IC50) of approximately 20 microM for both MLL and AT-2. Cell cycle analysis of treated MLL cells (10 microM 1,25-D3 for 48 hours) had 25% more cells in the G0/G1 phase than did control cells. To examine the in vivo effect of 1,25-D3 and the less hypercalcemic vitamin D analogue, Ro25-6760 (or 6760), on MLL PCa growth and metastasis, tumors (5 x 10(5) cells) were implanted subcutaneously into the flank of Copenhagen rats on the same day that treatment was initiated with 1,25-D3 (1 microgram) or 6760 (1 or 5 micrograms); rats received treatment three times a week. After 3 weeks, 1,25-D3 and 6760 (5 micrograms dosing) resulted in an inhibition of tumor volume and a reduction in the number and size of lung metastases. CONCLUSIONS: These preclinical studies demonstrate the profound in vitro, or in vivo, or both antiproliferative and differentiating effects of 1,25-D3 and 6760 on PCa and suggest that these drugs may have potential beneficial effects in the treatment of advanced PCa.

The pathobiology of the human enterochromaffin-like cell.

The significance of the enterochromaffin-like (ECL) cell as a critical endocrine regulator of gastric fundic mucosal function has only recently been recognized. Although the percentage of these cells present in the human fundic mucosa is less than that in rodents, the observation that they secrete histamine and are probably important modulators of parietal cell function has resulted in their attaining some considerable biological significance. The further identification of gastrin and somatostatin receptors on the surface of the ECL cells has suggested that other neurohormonal influences may be significant in the regulation of parietal cell function, utilizing the ECL cell as an intermediate modifier. While abnormalities of ECL cells in the human stomach (hyperplasia/neoplasia) have been mostly confined to observations in patients with pernicious anemia and atrophic gastritis, the recent recognition of hyperplasia in pharmacotherapeutically induced achlorhydric or hypochlorhydric states has excited considerable interest. It has been proposed that the generation of luminal hypo- or achlorhydria by powerful acid inhibitory pharmacotherapy may result in hypergastrinemia. This condition is responsible initially for the development of hyperplasia and, subsequently, possibly even neoplasia of the ECL system of the fundic mucosa. This phenomenon seems to be prevalent in rodents but has so far been only rarely observed in humans, e.g., pernicious anemia, atrophic gastritis. In particular, patients with the gastrinoma component of the multiple endocrine neoplasia type I syndrome exhibit ECL-cell hyperplasia and neoplasia after exposure to acid inhibitory pharmacotherapy. It is therefore likely that an underlying genomic phenomenon is necessary prior to the induction of hyperplasia and subsequent neoplastic transformation. The scientific evaluation of the relationship between gastrin, ECL-cell function, and the development of hyperplasia and neoplasia may provide some important information in regard to the molecular evolution of gastrointestinal neuroendocrine disease states. It is possible that the future pharmacotherapy of acid secretory disease may require regulation not only of parietal cell but of ECL-cell function.

Pathophysiology of varicoceles in male infertility.

Varicoceles are found in 19 to 41% of infertile men, and is one treatable form of male infertility. The mechanism by which varicoceles cause the variable effect on male infertility and spermatogenesis is still unknown. Experimental animal models play a useful (but limited) role due to the sudden and variable iatrogenic nature of the varicoceles and the duration of the studies. Much of the human data are derived by the characterization of associated differences in measurable parameters between men with and without varicoceles. The role of hyperthermia, testicular blood flow and venous pressure changes, reflux of renal/adrenal products, hormonal dysfunction, autoimmunity, defects in acrosome reaction, and oxidative stress, in the pathophysiology of varicocele will be discussed.

Vasectomy reversal for the post-vasectomy pain syndrome: a clinical and histological evaluation.

PURPOSE: The cause of the post-vasectomy pain syndrome is unclear. Some postulated etiologies include epididymal congestion, tender sperm granuloma and/or nerve entrapment at the vasectomy site. To our knowledge nerve proliferation has not been evaluated previously as a cause of pain. Vasectomy reversal is reportedly successful for relieving pain in some patients. We report our experience and correlate histological findings in resected vasal segments with outcome to explain the mechanism of pain in these patients. MATERIALS AND METHODS: We retrospectively reviewed the records of 13 men who underwent vasectomy reversal for the post-vasectomy pain syndrome. We compared blinded histological evaluations of the vasal ends excised at vasectomy reversal in these patients with those of pain-free controls who underwent vasectomy reversal to reestablish fertility. Controls were matched to patients for the interval since vasectomy. Histological features were graded according to the degree of severity of vasitis nodosum, chronic inflammation and nerve proliferation. RESULTS: Mean time to pain onset after vasectomy was 2 years. Presenting symptoms included testicular pain in 9 cases, epididymal pain in 2, pain at ejaculation in 4 and pain during intercourse in 8. Physical examination demonstrated tender epididymides in 6 men, full epididymides in 6, a tender vasectomy site in 4 and a palpable nodule in 4. No patient had testicular tenderness on palpation. Unilateral and bilateral vasovasostomy was performed in 3 and 10 of the 13 patients, respectively. Postoperatively 9 of the 13 men (69%) became completely pain-free. Mean followup was 1.5 years. We observed no differences in vasectomy site histological features in patients with the post-vasectomy pain syndrome and matched controls, and no difference in histological findings in patients with the post-vasectomy pain syndrome who did and did not become pain-free postoperatively. CONCLUSIONS: No histological features aid in identifying a cause of pain or provide prognostic value for subsequent pain relief. Vasectomy reversal appeared to be beneficial for relieving pain in the majority of select patients with the post-vasectomy pain syndrome.

Effect of prenatal vitamin D (calcitriol) exposure on the growth and development of the prostate.

BACKGROUND: We previously found that in the absence of testosterone (T), calcitriol promotes proliferation of normal prostatic stroma, while in the presence of T, it has a differentiating effect on prostatic epithelium. The present study was conducted to determine the effect of calcitriol exposure in utero on the postnatal development of the normal prostate. METHODS: Pregnant rats were injected subcutaneously with either 1.25 microg of calcitriol or vehicle alone on alternate days till delivery. Calcitriol-exposed and control pups were sacrificed at age 25 days (prepuberty), 63 days (postpuberty), or 102 days (adults), and their prostates and seminal vesicles were harvested and weighed. RESULTS: Pups prenatally exposed to calcitriol and sacrificed before puberty (25 days) had a 35% greater mean prostatic weight than controls (0.0314 vs. 0.0422 g, P < 0.007), and calcitriol-exposed adult rats (102 days) had a 68% greater mean prostatic weight than controls (0.1365 vs. 0.2304 g, P < 0.005). No differences were observed in seminal vesicle weights, and in serum calcium and testosterone levels. A disproportionately high mortality rate from sudden death (71%) was observed at puberty in uncastrated male rats prenatally exposed to calcitriol. CONCLUSIONS: These findings suggest that high-dose calcitriol exposure in utero may uniquely influence subsequent prostatic growth. Nonandrogenic steroids such as calcitriol may also be involved in genetic imprinting of the prostate.

Identification of nuclear matrix protein alterations associated with renal cell carcinoma.

PURPOSE: Neoplastic transformation, including renal cell carcinoma (RCC), is always accompanied by changes in nuclear morphology. Nuclear grading of RCC is based on characteristic alterations in nuclear shape, size, area and other morphologic parameters. The nuclear matrix, which forms the skeleton of the nucleus, determines nuclear morphology. Alterations in nuclear matrix protein (NMP) composition specific to tissue and cancer type have been described in a variety of human cancers. We conducted a study to analyze the nuclear matrix protein composition of renal cell carcinoma and compare it to that of normal renal tissue and renal cell carcinoma cells grown in culture. MATERIALS AND METHODS: We analyzed the nuclear matrix protein composition of RCC tumor tissue and that of normal kidney tissue obtained from seventeen patients undergoing radical nephrectomy for RCC. We also analyzed the NMP composition of two renal cancer cell lines (A-498 and 769-P). RESULTS: We were able to identify five different and unique NMPs which were present only in the human RCC tumor samples and were absent in all normal kidney tissue. One NMP was found specifically in the normal kidney tissue. All five RCC specific NMPs were also identified in the nuclear matrix of the two cell lines analyzed. CONCLUSIONS: Five nuclear matrix proteins specific and unique to RCC were identified. These NMPs are different from those previously identified in other tissues and neoplasms. The RCC specific NMPs identified in this study can potentially be used as diagnostic markers for renal cell carcinoma and for therapeutic tumor targeting.