Robert C. Dean

Expression profile of an androgen regulated prostate specific homeobox gene NKX3.1 in primary prostate cancer

PURPOSE NKX3.1, a member of the family of homeobox genes, exhibits prostate tissue specific expression and appears to play a role in mouse prostate development. Rapid induction of NKX3.1 gene expression in response to androgens has also been described. On the basis of the established role of androgens in prostatic growth and differentiation and studies showing an association of aberrant homeobox gene expression with the neoplastic process, we hypothesize that alterations of NKX3.1 gene expression play a role in prostate tumorigenesis. MATERIALS AND METHODS NKX3.1 expression was analyzed in matched, microdissected normal and tumor tissues from 52 primary prostate cancer specimens from radical prostatectomy by semiquantitative RT-PCR and in situ hybridization and correlated with the clinicopathologic features. NKX3.1 expression was quantified as differential expression between matched tumor and normal tissues and was grouped as overexpression in tumor tissue, reduced expression in tumor tissue and no change between tumor and normal tissues. Androgen regulation of NKX3.1 expression was also studied in LNCaP cells. Androgen receptor (AR) expression in prostate tumor and normal tissue was correlated with NKX3.1 expression. RESULTS Comparison of NKX3.1 expression between normal and tumor tissues revealed overexpression in 31% tumor specimens (16 of 52), decreased expression in 21% tumor specimens (11 of 52) and no change in 48% specimens (25 of 52). When these expression patterns were stratified by organ confined and non-organ-confined tumor, a higher percentage of patients exhibited NKX3.1 overexpression in non-organ confined tumor (40%) versus organ confined tumor (22%). Elevated NKX3.1 expression significantly correlated with tumor volume and serum prostate specific antigen (PSA) level in the NKX3.1 overexpression group (p<0.05). Metastatic prostate cancer cell lines did not exhibit mutations in the protein coding sequence of NKX3.1. Additionally, the NKX3.1 expression correlated with AR expression (p<0.01) in vivo in human prostate tissues. Comparison of PSA and NKX3.1 expression in response to androgen revealed a rapid androgen mediated induction of NKX3.1 expression in LNCaP cells. In situ hybridization analysis of representative specimens confirmed RT-PCR observations. CONCLUSIONS These results suggest an association of NKX3.1 with a more aggressive phenotype of carcinoma of the prostate. Correlation of AR expression with NKX3.1 in human prostate tissues underscores the androgen regulation of NKX3.1 in the physiologic context of human prostate tissues.

Treatment of Peyronie's disease with oral pentoxifylline

Background A 51-year-old male presented with a penile deformity without obvious etiology. Physical examination revealed hard plaques in the dorsal and ventral penis.Investigations Physical examination, penile ultrasound.Diagnosis Peyronies disease.Management Oral pentoxifylline.

Detection of circulating prostate specific antigen expressing prostatic cells in the bone marrow of radical prostatectomy patients by sensitive reverse transcriptase polymerase chain reaction.

PURPOSE The reverse transcriptase polymerase chain reaction (RT-PCR) assay for prostate specific antigen (PSA) expressing cells in the blood circulation has been under intense investigation since 1992. Although it has been suggested that this technology could be used as molecular staging for occult prostatic hematogenous metastases, we have been unable to confirm RT-PCR PSA positivity of peripheral blood to predict stage or recurrence in radical prostatectomy cases. We performed bone marrow RT-PCR PSA assay on a large cohort of radical prostatectomy cases and evaluate the use of this assay in improving prostate cancer staging and detecting early recurrence. MATERIALS AND METHODS Unilateral anterior iliac crest bone marrow aspirates were performed on 116 patients immediately before radical prostatectomy between February 1995 and September 1997. Radical prostatectomy specimens were processed as whole mounts. A sensitive nested RT-PCR assay with specific primers derived from the PSA sequence was used, which enabled us to detect PSA expressing LNCaP prostate cancer cells at the sensitivity of 1 cancer cell per 10 million lymphocytes (1/10(7)). A minimum of 3 RT-PCR PSA reactions were performed on all patients and at least 2 positive tests were required to define positivity. Patients were followed for PSA recurrence (mean followup 14.7 months). RESULTS PSA expressing cells were detected in bone marrow of 51 of 116 patients (44.0%) when at least 2 of 3 RT-PCR PSA assays per patient were positive. A much higher rate of RT-PCR PSA positivity was noted (77/116 patients, 66.3%) when any RT-PCR PSA positivity was considered. In 10 randomly selected cases the RT-PCR product was confirmed as PSA by deoxyribonucleic acid sequencing. Of 51 bone marrow RT-PCR positive cases 25 (49%) had organ confined disease and 26 (51%) had nonorgan confined disease. Similarly, bone marrow RT-PCR PSA was not associated with age, race, grade, pretreatment PSA or prostatic acid phosphatase value, clinical stage or margin status. However, the 2-year disease-free survival was 96.6% in RT-PCR negative patients versus 77.5% in RT-PCR positive patients (p = 0.054), and bone marrow RT-PCR PSA was an independent prognostic factor in multivariate analysis including PSA, Gleason grade and pathological stage. CONCLUSIONS Bone marrow RT-PCR PSA positivity in this study did not predict pathological stage, grade or margin positivity as determined from whole mount prostate cancer specimens. Furthermore, no relationship with age, grade or serum markers and bone marrow RT-PCR PSA positivity was noted. However, bone marrow RT-PCR PSA was associated with early disease recurrence. Further studies and longer followup are warranted to define the metastatic potential of the PSA expressing cells in the bone marrow of prostate cancer patients.

Blinded evaluation of reverse transcriptase-polymerase chain reaction prostate-specific antigen peripheral blood assay for molecular staging of prostate cancer.

OBJECTIVES The reverse transcriptase-polymerase chain reaction (RT-PCR)-prostate-specific antigen (PSA) assay to detect presumed occult micrometastatic prostate cancer has been controversial, and this molecular staging has been thought to be clinically useful by some groups but not others. METHODS We used a sensitive nested RT-PCR assay with specific primers derived from the PSA sequence and a very stringent two-step PCR protocol with denaturing temperature of 94 degrees C annealing and extension temperature of 68 degrees C. This method enabled us to detect PSA-expressing LNCaP prostate cancer (PC) cells as low as one cell of 10 million lymphocytes (1/10(7)). Ninety-six patients with PC were studied, including 85 before radical prostatectomy (RP), and 22 controls, including healthy men and women and men with benign prostatic hyperplasia. RESULTS In 85 patients undergoing RP, a minimum of two independent RT-PCR-PSA assays detected circulating prostate cells preoperatively in 27 patients (31.8%). Of 12 patients with locally advanced or advanced stage cancer, RT-PCR-PSA was positive in 5 (41.7%); of the 22 controls, no patient was RT-PCR-PSA positive. In 10 randomly selected cases, the RT-PCR product was confirmed as PSA by DNA sequencing. Of the 27 patients undergoing RP who were RT-PCR positive, 11 (40.7%) had non-organ-confined disease (pT3a or greater), and of the 58 patients who were RT-PCR negative, 32 (55.2%) had non-organ-confined disease. Patients with RT-PCR positive results also had lower margin positivity (9 of 27, 33.3%) than did patients with RT-PCR negative results (21 of 58, 36.2%). Finally, at a mean follow-up of 25.7 months, 5 (18.5%) of 27 RT-PCR positive patients had recurrence (PSA) compared with 14 (24.1%) of 58 RT-PCR negative patients. CONCLUSIONS On the basis of this blinded study, RT-PCR for PSA-expressing cells in 85 patients before RP is not related to clinical stage, age, race, grade, Gleason sum, serum PSA or prostatic acid phosphatase, tumor volume, or tumor multifocality. RT-PCR positivity did not predict pathologic stage or early PSA recurrence. A standardized RT-PCR assay needs to be developed to account for interlaboratory discrepancies.

Peyronie's disease: advancements in recent surgical techniques.

Purpose of review The aim of this review is to discuss the recent advances in surgical techniques for the correction of Peyronies disease. A review of the literature published in 2002 and 2003 regarding surgical treatment was performed in preparation for this article. Recent findings The surgical treatment of Peyronies disease remains a debated topic. Generally, surgical therapy for Peyronies disease can be divided into three main categories: wedge resection/plication surgeries; plaque excision/incision with grafting procedures; and the placement of a penile prosthesis. New reports have investigated suture selection, graft acceptability, and new surgical approaches. These new surgical enhancements will give urologists a greater choice in the surgical management of Peyronies disease. This will aid the ability of the urologist to tailor the therapy necessary for each individual patient. Summary The correction of acquired penile deformity seen in Peyronies disease patients can be a challenge for the practising urologist. Newer advancements in surgical techniques and materials will allow the urologist greater treatment options. The degree of curvature, the type of deformity, erectile dysfunction, and penile length are all characteristics that are assessed in choosing the best surgical intervention in Peyronies disease. Surgical therapy can be quite beneficial for patients who suffer from penile deformity and can greatly improve their quality of life.

p53 Immunostaining guided laser capture microdissection (p53-LCM) defines the presence of p53 gene mutations in focal regions of primary prostate cancer positive for p53 protein

Objectives: A wide range of p53 mutations (5–65%), detected by various methods, has been reported in primary prostate cancers (CaP). IHC staining of radical prostatectomy specimens shows marked heterogeneity of focally distributed p53-positive cells. However, a significant relationship between the focal staining of p53 and cancer recurrence after radical prostatectomy has been noted. Increased frequency of p53 mutations has been generally observed in advanced stage CaP and metastatic prostate cancer cell lines. The significance of focal p53 immunostaining in primary CaP remains uncertain with respect to the p53 gene mutation or tumor progression. The goal of this study was to evaluate p53 gene mutations in focal regions of primary prostate cancers positive by p53 immunostaining.Methods: Whole-mount prostates from men with clinically organ-confined prostate cancer were immunostained for p53 protein. Laser capture microdissection (LCM) was used to harvest p53 positive cells from areas of tumor and prostatic intraepithelial neoplasia and benign gland. DNA from microdissected cells were amplified for p53 exons 5–8 by polymerase chain reaction (PCR) and analyzed for mutations by single strand conformation polymorphism and DNA sequencing. Mutation analysis of the p53 gene exons 5–8 was performed in the p53 immunostaining positive focal regions (1+ to 4+) of whole-mount prostate sections from 16 patients.Results: Of 16 patients with p53 IHC positive tumors, 11 (69%) had p53 gene mutations as determined by DNA sequence analysis. However, randomly microdissected tumor cells from 4 of 18 patients (22%) negative for p53 IHC also demonstrated mutations in the p53 gene. A significant fraction of prostate tumors with focally positive immunostaining for p53 have been confirmed to contain mutations in the p53 gene.Conclusions: p53 immunostaining guided LCM combined with DNA-based analyses emphasizes the presence of focal p53 mutations in primary prostate cancers and underscores the significance of previous observations showing a correlation between focal p53 immunostaining in primary CaP and cancer recurrence after radical prostatectomy.

NEW TUMOR MARKERS OF TESTIS CANCER

Potential tumor markers for testis cancer have become numerous with the new molecular techniques available. New protein markers have been evaluated, and histologic factors have shown correlations with stage of disease. Cytogenetic analysis studies have also shown associations with stage progression. Chromosomal markers, oncogenes, and tumor suppressor genes are possible candidates for tumor markers. These new potential tumor markers may become as commonplace as the established markers and may enhance diagnosis, staging, and treatment of testis cancer.

Vardenafil: efficacy, tolerability and future directions

Vardenafil is a short-acting PDE5 inhibitor used in the treatment of male erectile dysfunction. It is the most potent and specific of the three commercially available PDE5 inhbitors, which may decrease incidence of side effects, although this has not been demonstrated clinically. Although its efficacy in the treatment of erectile dysfunction has been demonstrated in several studies, recent and continuing studies have shown vardenafils promise as an effective agent in penile rehabilitation, decreasing lower urinary tract symptoms resulting from benign prostatic hyperplasia and management of pulmonary hypertension.

Leiomyosarcoma of the Urinary Bladder in a Teenage Male

Malignant neoplasms of the bladder are typically transitional cell carcinoma with squamous cell carcinoma and adenocarcinoma comprising nearly all of the remaining cases. Leiomyosarcoma is a rarely seen neoplasm of the bladder with a generally poor prognosis. It is important to distinguish leiomyosarcomas from rhabdomyosarcoma with the aid of immunohistochemical markers. A therapeutic dilemma exists with regard to the need for urethrectomy. We present the third reported case of leiomyosarcoma of the bladder in a teenage male patient.

Vardenafil in Erectile Dysfunction: The Evidence of Its Therapeutic Value

Abstract: Erectile dysfunction (ED) is a condition that affects approximately 18 million American men. Phosphodiesterase-5 inhibitors (PDE5i’s) have revolutionized the treatment of erectile dysfunction by providing the first highly-effective oral medication. Vardenafil is one of 3 PDE5i’s commercially available for the treatment of ED in the United States. It has demonstrated therapeutic efficacy in the management of uncomplicated ED as well as more refractory cases associated with diabetes and surgery for prostate cancer. The physiology, pharmacokinetics, pharmacodynamics, and primary literature evaluating vardenafil are reviewed.