title: The expression of pluripotency marker Oct 3/4 in prostate cancer and benign prostate hyperplasia.
abstract: BACKGROUND
  Oct 3/4 (Octamer 3/4), a member of POU family has been considered as an important stem cell marker and essential transcription factor during human embryogenesis. In recent years, there have also been reports on presence of Oct 3/4 in differentiated benign and malignant human cells. The objective of this study was to investigate the transcription and the protein expression of Oct 3/4 isoforms in prostate cancer and benign prostate tissue.
  
  
  METHODS
  Thirty sex adenocarcinomas and eight cases of benign prostate hyperplasia were studied. The transcription of Oct 3/4 was analyzed using RT-PCR approach associated with restriction digestion analysis. Oct 3/4 protein expression was studied by immunohistochemistry on paraffin sections using two different antibodies.
  
  
  RESULTS
  We identified only the transcript 2 of Oct 3/4 in prostate tumors and benign prostate hyperplasia. Immunohistochemistry verified these results, demonstrating only cytoplasmic localization of Oct 3/4. Transcription of type 1 of Oct 3/4 as well as protein expression with nuclear localization of Oct 3/4 isoform 1 were not detected. Oct 3/4 immunopositive tumors were also displayed neuroendocrine differentiation and showed androgen receptor immunopositivity. The stem cell markers CD44 and CD117 were not detected in Oct 3/4 immunopositive cells.
  
  
  CONCLUSIONS
  Our results indicate that only the cytoplasmic isoform 2 of Oct 3/4 is present in prostate cancer and benign prostate hyperplasia. The malignant and benign prostate cells, which are immunopositive for variant 2 of Oct 3/4, lack other stem cell markers supporting previously published data that variant 2 of Oct 3/4 is not a pluripotency marker.
authors.affiliation: Division of Pathology, Department of Laboratory Medicine, Lund University Hospital, Lund, Sweden. nastaran.monsef@med.lu.se
authors.forename: Nastaran
authors.initials: N
authors.lastname: Monsef
authors.forename: Maria
authors.initials: M
authors.lastname: Soller
authors.forename: Margareth
authors.initials: M
authors.lastname: Isaksson
authors.forename: Per Anders
authors.initials: PA
authors.lastname: Abrahamsson
authors.forename: Ioannis
authors.initials: I
authors.lastname: Panagopoulos
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D000906:Antibodies; D000918:Antibody Specificity; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism*; D039904:Pluripotent Stem Cells / Q000378:metabolism / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000378:metabolism* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000906:Antibodies; D014408:Biomarkers, Tumor; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human