Lithium, a widely used treatment for bipolar affective disorders, often. causes nephrogenic diabetes insipidus. The effect of chronic lithium therapy on the expression of the vasopressin-regulated water channel Aquaporin-2 (AQP2) in rat kidney was examined. Membranes were prepared from inner medulla of one kidney from each rat, while the contralateral one was fixed for iminunofluorescence and immunoelectromnicroscopy. Immunoblotting revealed that lithium treatment reduced AQP2 expression dramatically, to 31±8% after 10 d and to 4±1% after 25 d, coincident with development of severe polyuria. Immunofluorescence and immunogold quantitation confirmed the lithium-induced decrease in AQP2 expression (from 11.2±1.0 to 1.1±0.2 particles/,um2). The downregulation was only partly reversed by return to lithium-free diet for 1 wk (40±8% of control). Furthermore, immunoblotting and immunogold quantitation revealed that 2 d of thirsting or 7 d of dDAVP treatment, in the continued presence of lithium, increased AQP2 expression by six-and threefold, respectively, coincident with increased urinary osmolality. Thirsting increased AQP2 immunolabeling mainly of vesicles, whereas dDAVP caused accumulation of AQP2 predominantly in the subapical region and plasma membrane. Thus, lithium causes marked downregulation of AQP2 expression, only partially reversed by cessation of therapy, thirsting or dDAVP treatment, consistent with clinical observations of slow recovery from lithium-induced urinary concentrating defects. (J. Clin. Invest. 1995. 95:1838-1845

Abstract. The study was performed to elucidate the distribution and cellular localization of cyclooxygenase (COX

BackgroundImmunohistochemistry using antibody cocktails against basal cell specific and cancer-associated markers is important in the diagnosis of prostate carcinoma in needle biopsies. We compared the usefulness for detecting prostate carcinoma of a three-marker cocktail of antibodies to α-methylacyl-CoA racemase (AMACR), p63 and cytokeratin (CK) 5 with a traditional two-marker cocktail of AMACR and p63.MethodsSixty-six prostate needle biopsies were analysed prospectively. Serial sections were immunostained with the two- and three- antibody cocktails. Blinded slides were assessed individually by two pathologists and sensitivity, specificity and kappa statistics were calculated.ResultsBoth antibody cocktails contributed to the detection of prostate carcinoma in needle biopsies. There was an acceptable level of agreement between the pathologists for both the cocktails. Sensitivity was similar for one pathologist comparing both the cocktails (76.4% and 75.7%), but was slightly lower comparing the three-antibody with the two-antibody cocktail for the other pathologist (66.6% vs. 77.4%, respectively). Higher specificity values of 90.3% were achieved by both pathologists using three-antibody as compared with two-antibody cocktails (68.7% and 71.8%).ConclusionsAntibody cocktails are important in diagnosing prostate carcinoma in needle biopsies. Adding an extra basal cell marker to the traditional two-antibody cocktail improves the specificity of detecting prostate carcinoma in limited needle biopsy material, and should be considered for routine diagnostic use.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2492231327330327

Purpose: This study investigates SLC18A2 (vesicular monoamine transporter 2) expression in prostate adenocarcinoma and examines its potential as a predictive marker for prostate cancer patient outcome after radical prostatectomy. Experimental Design: Expression and single nucleotide polymorphism microarray analyses identified SLC18A2 as both down-regulated and subject to common loss-of-heterozygosity in prostate cancer. Down-regulated SLC18A2 expression was validated on tissue microarrays containing benign and malignant prostate specimens from an independent patient group (n = 738). Furthermore, SLC18A2 immunoreactivity in radical prostatectomy tumor specimens (n = 506) was correlated to clinicopathologic characteristics and recurrence-free survival. The possibility of SLC18A2 silencing by aberrant DNA methylation in prostate cancer cells was investigated by bisulfite sequencing. Results: Tissue microarray analysis revealed markedly lower cytoplasmic SLC18A2 staining in cancer compared with nonmalignant prostate tissue samples, confirming RNA expression profiling results. Furthermore, multivariate analysis identified cytoplasmic SLC18A2 immunoreactivity as a novel predictor of biochemical recurrence following prostatectomy (hazard ratio, 0.485; 95% confidence interval, 0.333-0.709; P < 0.001) independent of prostate-specific antigen, Gleason score, tumor stage, and surgical margin status. SLC18A2 showed loss-of-heterozygosity in 23% of the tumors and was densely hypermethylated in 15 of 17 (88%) prostate cancer samples plus 6 of 6 prostate cancer cell lines. In contrast, SLC18A2 was unmethylated in 4 of 4 adjacent nonmalignant prostate and 3 of 5 benign prostatic hyperplasia tissue samples, whereas 2 of 5 benign prostatic hyperplasia samples had monoallelic hypermethylation. Methylation and histone deacetylase inhibitory agents rescued SLC18A2 expression in three prostate cancer cell lines. Conclusions: SLC18A2 silencing by DNA hypermethylation and/or allelic loss is a frequent event inprostate cancerandanovelindependent predictorofbiochemicalrecurrenceafterprostatectomy.

Transcription factor Snail1 is a mediator of cell migration and survival, and expression is elevated in several cancer types. The Snail1 gene is reportedly amplified in prostate cancer (PC), and we investigated Snail1 expression in PC. Immunohistochemical Snail1 staining was determined on a tissue microarray which includes 327 specimens of PC, 30 specimens from patients with benign prostatic hyperplasia (BPH), benign tissue from 30 PC patients and 15 high-grade prostate intraepithelial neoplasia (high-grade PIN) specimens. Clinicopathological and follow-up data were available for all patients. No BPH specimen and only 21% of benign tissue from PC patients showed high expression of Snail1. Only 7% of high-grade PIN patients expressed a high level of Snail1. In contrast, approximately 50% of PC tissue from patients with PC showed marked nuclear immunostaining. Snail1 immunostaining was significantly associated with Gleason score (p<0.05). Snail1 expression was not correlated to T stage, metastasis at time of diagnosis, risk of or time to recurrence. Snail1 expression was significantly increased in PC with a positive correlation to dedifferentiation, but not to cancer progression or prognosis. The presented data indicate that Snail1 expression is upregulated from the early stages of PC.