Genetic and epigenetic SLC18A2 silencing in prostate cancer is an independent adverse predictor of biochemical recurrence after radical prostatectomy.

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 in prostate cancer and a novel independent predictor of biochemical recurrence after prostatectomy.

Secretagogin is a new neuroendocrine marker in the human prostate.

BACKGROUND: Neuroendocrine (NE) differentiation in prostate cancer (PCa), promoted by NE cell secreted products, appears to be associated with tumor progression, poor prognosis, and hormone-refractory disease. We recently reported secretagogin, a hexa-EF-hand Ca(2+) binding protein, as a novel NE marker in carcinoid tumors of the lung and the gastrointestinal tract. The present study analyzes the expression of secretagogin in normal and malign prostate tissue. METHODS: We analyzed immunoreactivity for secretagogin, chromogranin A (CgA), neuron specific enolase (NSE), and synaptophysin (SYN) in consecutive sections from 87 formalin-fixed paraffin-embedded (FFPE) benign hyperplastic (n = 10) and prostate adenocarcinoma (n = 77) specimens. The intracellular distribution of secretagogin, CgA, and NSE was examined by confocal fluorescent microscopy, and we characterized secretagogin in eight samples by Western blotting. RESULTS: Secretagogin is cytoplasmic and nuclear expressed in NE and NE differentiated cells, and to a lesser extent in epithelial cells, in the benign prostate and prostate adenocarcinoma cells. Secretagogin stained 82% (46/56) of benign and 71% (48/68) of prostate adenocarcinomas and co-localized with the NE markers CgA and NSE. The expression of secretagogin is significantly correlated to CgA (P < 0.001) and NSE (P < 0.048) in prostate adenocarcinoma and to CgA in normal epithelium (P < 0.028). CONCLUSIONS: Secretagogin is a novel NE marker in the prostate with more extended immunoreactivity compared to the NE markers CgA, SYN, and NSE. Secretagogin is widely expressed in prostatic adenocarcinoma as opposed to adenocarcinomas in other organs.

Allergy in bakers' apprentices and factors associated to non-participation in a cohort study of allergic sensitization.

OBJECTIVE: To describe the prevalence of atopy and respiratory symptoms among baker apprentices at the start of the education and factors associated with non-participation in the study. METHODS: A total of 346 students, 22.1(0.6) years of age, mean (SD), from the food production programme of technical colleges in Denmark were invited to participate in a 3 year study. Of the students, 187 agreed to participate and filled in a physician-administered questionnaire. The presence of atopy was determined by skin prick test (SPT) and serum allergen specific IgE (SpIgE). Bronchial hyper responsiveness to methacholine (PD(20)

Response of respiratory flour allergics in an ingested flour challenge may involve plasmacytoid dendritic cells, CD25+ and CD152+ T cells.

BACKGROUND: A number of occupational respiratory allergens are food related, and little is known about the responses these allergens elicit in sensitized persons that ingest them. METHODS: Nine respiratory flour-allergic volunteers were exposed in a double-blind placebo-controlled food challenge with flour. Responses were monitored by spirometry, acoustic rhinometry, determination of urinary methyl histamine and tryptase and flow cytometric evaluation of basophil, dendritic and T cell numbers and markers. RESULTS: Significant increases in serum tryptase (compared with placebo post-exposure levels) and methyl histamine and a coordinated decrease in blood basophils and nasal volume after ingestion of allergen compared with placebo suggest an allergic response to ingested allergen. There was no change in forced expiratory volume in 1 s. The number of blood plasmacytoid dendritic cells (DC), but not of myeloid DC, decreased after exposure (p = 0.001). DC HLA DR was reduced after both exposures (p < 0.001). Expression of CXCR4 on DC was reduced after allergen (p = 0.033) but not after placebo exposure. CD4+ T cell expression of CD25 was elevated after placebo (p = 0.021) but reduced after allergen provocation. The reduction in CD25 expression after allergen compared with placebo was significant (p = 0.024). CD152 was downregulated on these cells after allergen (p = 0.039) but less so after placebo exposure. CONCLUSION: Persons with respiratory allergy respond after ingestion of the relevant allergen. Response to this allergen challenge may selectively recruit plasmacytoid DC through CXCR4 and T cells expressing CD25 and CD152, which may be a regulatory phenotype.

Analysis of the zwf-pgl-eda-operon in Pseudomonas putida strains H and KT2440.

A 3.9-kb fragment of the genome of Pseudomonas putida H, containing the complete zwf-pgl-eda-operon, encoding glucose 6-phosphate dehydrogenase, 6-phosphogluconolactonase and 2-keto-3-deoxy-6-phosphogluconate-aldolase, respectively, and part of the divergently transcribed regulatory gene, hexR, was cloned and analyzed. The nucleotide sequences of these genes showed high similarities to the corresponding DNA sequences of P. putida KT2440 and also to sequences of Pseudomonas aeruginosa PAO1. Derivatives of strains H and KT2440, containing transcriptional lacZ fusions to P(zwf) were generated and used to study the expression of these operons. In both strains, this operon was induced by carbohydrates such as glucose, gluconate, fructose and glycerol. The transcription rate of the zwf-pgl-eda-operon was found to be about three times higher in the KT2440 background than in strain H. In both strains the induction of the zwf-pgl-eda-operon by carbohydrates during growth on carboxylic acids was not affected by carbon catabolite repression.