title: Comprehensive expression analysis of L-dopa decarboxylase and established neuroendocrine markers in neoadjuvant hormone-treated versus varying Gleason grade prostate tumors.
abstract: Current hormone withdrawal therapies used for treatment of advanced prostate cancer lead to androgen-independent tumor growth. Increased prostatic neuroendocrine (NE) cell density has been implicated in promoting progression of prostate cancer, but the process by which this occurs remains unclear. The aim of this study was to determine whether there is an association of increased NE differentiation with neoadjuvant hormone therapy and Gleason grade. Using adjacently sectioned tissue microarrays, the expression profile of novel and known NE markers were monitored. L-Dopa decarboxylase (DDC), a catecholamine synthesis enzyme and androgen receptor (AR) coregulator protein, was identified as an additional NE marker of prostate cancer. Immunohistochemical analysis of DDC with the established NE markers, chromogranin A and bombesin, revealed a significant increase in NE differentiation after 6 months of hormone therapy and after progression to androgen independence but no apparent correlation with Gleason grade. In addition, dual immunofluorescence analysis revealed that approximately 55% of the mixed population of DDC- and chromogranin A-expressing NE cells continue to express AR. Taken together, these results suggest that the increase of NE differentiation in prostate cancers depends specifically on duration of hormone therapy. This increase may be due to the transdifferentiation of AR-expressing epithelial-derived adenocarcinoma cells into an NE cell phenotype.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5.
authors.forename: Latif A
authors.initials: LA
authors.lastname: Wafa
authors.forename: Jodie
authors.initials: J
authors.lastname: Palmer
authors.forename: Ladan
authors.initials: L
authors.lastname: Fazli
authors.forename: Antonio
authors.initials: A
authors.lastname: Hurtado-Coll
authors.forename: Robert H
authors.initials: RH
authors.lastname: Bell
authors.forename: Colleen C
authors.initials: CC
authors.lastname: Nelson
authors.forename: Martin E
authors.initials: ME
authors.lastname: Gleave
authors.forename: Michael E
authors.initials: ME
authors.lastname: Cox
authors.forename: Paul S
authors.initials: PS
authors.lastname: Rennie
mesh_terms: D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D001839:Bombesin / Q000032:analysis; D002454:Cell Differentiation; D053379:Chromogranin A / Q000032:analysis; D004296:Dopa Decarboxylase / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D009490:Neurosecretory Systems / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011944:Receptors, Androgen / Q000032:analysis; D012720:Severity of Illness Index
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D053379:Chromogranin A; D011944:Receptors, Androgen; D004296:Dopa Decarboxylase; D001839:Bombesin