title: Alterations of GPI transamidase subunits in head and neck squamous carcinoma.
abstract: BACKGROUND
  GPI anchor attachment is catalyzed by the GPI transamidase (GPIT) complex. GAA1, PIG-T and PIG-U are the three of five GPIT subunits. Previous studies demonstrated amplification and overexpression of GPIT subunits in bladder and breast cancer with oncogenic function. We performed an analysis of these subunits in head and neck squamous cell carcinoma (HNSCC).
  
  
  RESULTS
  To evaluate GAA1, PIG-T and PIG-U in HNSCC, we used quantitative PCR (QPCR) and quantitative RT-PCR (QRT-PCR) to determine the copy number of those genes in primary tumors and the matching lymphocytes in 28 patients with HNSCC and quantified RNA expression of those genes in 16 primary HNSCC patients and 4 normal control tissue samples. GAA1 showed a significant increase in normalized mRNA expression, 2.11 (95% CI: 1.43, 2.79), in comparison to that of normal controls, 0.43 (95% CI: -0.76, 1.61), p = 0.014 (Mann-Whitney test). The mean genomic copy number of GAA1 was significantly increased in HNSCC, 0.59 (95% CI: 0.50, 0.79), in comparison to lymphocyte DNA, 0.35 (95% CI: 0.30, 0.50), p = 0.001 (paired t-test).
  
  
  CONCLUSIONS
  An increased expression level and elevated copy number for GAA1 suggest a role for this GPI anchor subunit in HNSCC.
authors.affiliation: Department of Otolaryngology- Head and Neck Surgery, Head and Neck Cancer Research Division, Johns Hopkins Medical Institutions, 601 N. Caroline Street, 6th Floor, Baltimore, MD 21287-0910, USA. wwjiang33@hotmail.com
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Jiang
authors.forename: Marianna
authors.initials: M
authors.lastname: Zahurak
authors.forename: Zeng-Tong
authors.initials: ZT
authors.lastname: Zhou
authors.forename: Hannah Lui
authors.initials: HL
authors.lastname: Park
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Guo
authors.forename: Guo-Jun
authors.initials: GJ
authors.lastname: Wu
authors.forename: David
authors.initials: D
authors.lastname: Sidransky
authors.forename: Barry
authors.initials: B
authors.lastname: Trink
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Califano
mesh_terms: D000217:Acyltransferases / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D016022:Case-Control Studies; D002460:Cell Line; D018628:Gene Dosage / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D016133:Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C093316:GPAA1 protein, human; D008562:Membrane Glycoproteins; D000217:Acyltransferases; C081007:COOH-terminal signal transamidase