title: Differential expression of osteoblast-specific factor 2 and polymeric immunoglobulin receptor genes in nasopharyngeal carcinoma.
abstract: BACKGROUND
  The molecular mechanisms leading to development of nasopharyngeal carcinoma (NPC) are not well understood. To delineate the features of NPC, we tried to identify unique expression of cellular genes in the tumor biopsy specimens.
  
  
  RESULTS
  By use of a combination of differential display and cDNA microarray analysis, we found two genes, 3E5 and 4A5, to show unique expression in the NPC biopsy specimens compared with nontumor nasopharyngeal tissues. Expression of 3E5, the osteoblast-specific factor-2 (OSF-2) gene, was detected at significantly higher levels in NPC biopsy specimens than that in control tissues, a finding confirmed using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). A correlation between expression of OSF-2 and its regulatory cytokine transforming growth factor-beta was observed in nontumor tissues but not in NPC biopsy specimens. On the other hand, expression of 4A5, whose sequences represent the 3' untranslated region of the polymeric immunoglobulin receptor (pIgR) gene, was detected rarely in NPC specimens but frequently in nontumor controls. The expression of pIgR in normal epithelial cells, but not in NPC tumor cells, was verified by RT-PCR and immunohistochemical staining.
  
  
  CONCLUSIONS
  NPC shows significant upregulation of OSF-2 and downregulation of pIgR. Expression of OSF-2 is likely to play a role in the pathogenesis of NPC. In addition, expression of OSF-2 and pIgR is disassociated with the expression of their regulatory cytokines in NPC biopsy specimens, suggesting that the tumors may have altered responses to certain cytokines.
authors.affiliation: Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Number 1, Section 1, Jen-Ai Road, Taipei, Taiwan.
authors.forename: Yao
authors.initials: Y
authors.lastname: Chang
authors.forename: Tso-Ching
authors.initials: TC
authors.lastname: Lee
authors.forename: Jian-Chiuan
authors.initials: JC
authors.lastname: Li
authors.forename: Ting-Lung
authors.initials: TL
authors.lastname: Lai
authors.forename: Huey-Huey
authors.initials: HH
authors.lastname: Chua
authors.forename: Chi-Long
authors.initials: CL
authors.lastname: Chen
authors.forename: Shin-Lian
authors.initials: SL
authors.lastname: Doong
authors.forename: Chen-Kung
authors.initials: CK
authors.lastname: Chou
authors.forename: Tzung-Shiahn
authors.initials: TS
authors.lastname: Sheen
authors.forename: Ching-Hwa
authors.initials: CH
authors.lastname: Tsai
mesh_terms: D015815:Cell Adhesion Molecules / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D019056:Receptors, Polymeric Immunoglobulin / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D015815:Cell Adhesion Molecules; C512835:POSTN protein, human; D019056:Receptors, Polymeric Immunoglobulin; D016212:Transforming Growth Factor beta