title: Decreased expression of glutathione S-transferase pi correlates with poorly differentiated grade in patients with oral squamous cell carcinoma.
abstract: BACKGROUND
  Glutathione S transferase pi (GSTP1) is a member of phase II detoxification enzymes as a major regulator of cell signaling in response to stress, hypoxia, growth factors, and other stimuli. The clinical role of GSTP1 in cancer is still unclear. The aim of this study was to investigate the serum GSTP1 level in patients with oral squamous cell carcinoma (OSCC) and the GSTP1 expression in tissue samples from patients with OSCC and OSCC lines.
  
  
  METHODS
  One hundred and sixty-six patients with OSCC and 120 normal persons were used to screen potential serum peptide biomarkers using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Serum GSTP1 concentration was detected in 18 patients with OSCC and 18 normal persons using ELISA. Immunohistochemistry was used to detect GSTP1 expression in tissue samples from twenty-eight OSCC patients. Western blot and real-time PCR were used to detect GSTP1 expression in nine OSCC lines.
  
  
  RESULTS
  Decreased GSTP1 concentration was found in the patients with OSCC compared with the normal persons by MALDI-TOF-MS, which was then confirmed by ELISA (P = 0.019). Decreased GSTP1 mRNA level and protein expression were also found in the OSCC lines. Decreased GSTP1 expression was found correlating with pathological differentiation grade in the tissue samples from OSCC patients, a lower GSTP1 expression indicating a poorer pathological differentiation grade (P = 0.041).
  
  
  CONCLUSIONS
  These results suggest that decreased GSTP1 expression in patients with OSCC and a lower GSTP1 expression indicating a poorer pathological differentiation grade in OSCC tissue samples.
authors.affiliation: Department of Oral & Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Hai-long
authors.initials: HL
authors.lastname: Ma
authors.forename: Cong
authors.initials: C
authors.lastname: Yu
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yi-ran
authors.initials: YR
authors.lastname: Tan
authors.forename: Jin-ke
authors.initials: JK
authors.lastname: Qiao
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.forename: Li-zhen
authors.initials: LZ
authors.lastname: Wang
authors.forename: Jiang
authors.initials: J
authors.lastname: Li
authors.forename: Qiong
authors.initials: Q
authors.lastname: Chen
authors.forename: Fu-xiang
authors.initials: FX
authors.lastname: Chen
authors.forename: Zhi-yuan
authors.initials: ZY
authors.lastname: Zhang
authors.forename: Lai-ping
authors.initials: LP
authors.lastname: Zhong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000201:enzymology / Q000473:pathology*; D002460:Cell Line; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D051549:Glutathione S-Transferase pi / Q000097:blood*; D006801:Humans; D007150:Immunohistochemistry; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000097:blood / Q000201:enzymology / Q000473:pathology*; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D058185:Magnetite Nanoparticles; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi
keywords: glutathione S-transferase pi; oral squamous cell carcinoma; pathological differentiation grade