title: Expression of hypoxia-inducible factor-1 alpha is significantly associated with the progression and prognosis of oral squamous cell carcinomas in Taiwan.
abstract: BACKGROUND
  Overexpression of hypoxia-inducible factor-1 alpha (HIF-1 alpha) has been found to be significantly associated with the tumor invasion, lymph node metastasis, clinical stage, and prognosis of a variety of human cancers.
  
  
  METHODS
  This study examined the expression of HIF-1 alpha in 57 specimens of oral squamous cell carcinoma (OSCC), 41 specimens of oral epithelial dysplasia (OED, 12 mild, 17 moderate, and 12 severe OED cases), and 14 specimens of normal oral mucosa (NOM) by immunohistochemistry.
  
  
  RESULTS
  We found that the mean nuclear HIF-1 alpha labeling indices (LIs) increased significantly from NOM (9 +/- 6%) through mild OED (25 +/- 18%), moderate OED (41 +/- 27%), and severe OED (42 +/- 22%) to OSCC samples (55 +/- 23%, P < 0.001). A significant correlation was found between the higher mean nuclear HIF-1 alpha LI and OSCCs with larger tumor size (P < 0.001), regional lymph node metastasis (P < 0.001), or more advanced clinical stages (P < 0.001). Only larger tumor size (P = 0.002) and nuclear HIF-1 alpha LI >or= 60% (P = 0.048) were identified as independent unfavorable prognosis factor by multivariate analyses with Cox regression model. Kaplan-Meier curve showed that OSCC patients with a nuclear HIF-1 alpha LI >or= 60% had a significantly poorer cumulative survival than those with a nuclear HIF-1 alpha LI < 60% (log-rank test, P = 0.022).
  
  
  CONCLUSIONS
  We conclude that the expression of HIF-1 alpha is an early event in oral carcinogenesis. The nuclear HIF-1 alpha LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients.
authors.affiliation: Graduate Institute of Clinical Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Pin-Yi
authors.initials: PY
authors.lastname: Lin
authors.forename: Chuan-Hang
authors.initials: CH
authors.lastname: Yu
authors.forename: Jeng-Tzung
authors.initials: JT
authors.lastname: Wang
authors.forename: Huang-Hsu
authors.initials: HH
authors.lastname: Chen
authors.forename: Shih-Jung
authors.initials: SJ
authors.lastname: Cheng
authors.forename: Mark Yen-Ping
authors.initials: MY
authors.lastname: Kuo
authors.forename: Chun-Pin
authors.initials: CP
authors.lastname: Chiang
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D000704:Analysis of Variance; D014408:Biomarkers, Tumor; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis*; D007124:Immunoenzyme Techniques; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D012907:Smoking; D013624:Taiwan
chemical_list: D014408:Biomarkers, Tumor; D051795:Hypoxia-Inducible Factor 1, alpha Subunit