title: USP22 is useful as a novel molecular marker for predicting disease progression and patient prognosis of oral squamous cell carcinoma.
abstract: OBJECTIVE
  The significance of ubiquitin-specific protease 22 (USP22) as a potential marker has been growing in the field of oncology. The aim of this study was to investigate the role of USP22 and the association with its potential targets in oral squamous cell carcinoma (OSCC).
  
  
  METHODS
  Immunohistochemistry was used to determine the expression of USP22 protein in 319 OSCC patients in comparison with 42 healthy controls. The clinical correlations and prognostic significance of the aberrantly expressed protein was evaluated to identify novel biomarker of OSCC.
  
  
  RESULTS
  The incidence of positive USP22 expression was 63.32% in 319 conventional OSCC tissues. The protein expression level of USP22 was concomitantly up-regulated from non-cancerous mucosa to primary carcinoma and from carcinomas to lymph node metastasis (P<0.001). Moreover, statistical analysis showed that positive USP22 expression was positively related to lymph node metastasis, Ki67, Cox-2 and recurrence. Furthermore, it was shown that patients with positive USP22 expression had significantly poorer outcome compared with patients with negative expression of USP22 for patients with positive lymph nodes. Multivariate Cox regression analysis revealed that USP22 expression level was an independent prognostic factor for both overall survival and disease-free survival (P<0.001 and P<0.001, respectively). Cancer cells with reduced USP22 expression exhibited reduced proliferation and colony formation evaluated by MTT and soft agar assays.
  
  
  CONCLUSIONS
  To our knowledge, this is the first study that determines the relationship between USP22 expression and prognosis in OSCC. We found that increased expression of USP22 is associated with poor prognosis in OSCC. USP22 may represent a novel and useful prognostic marker for OSCC.
authors.affiliation: Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Piao
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.forename: Fulin
authors.initials: F
authors.lastname: Guo
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Yao
authors.initials: Y
authors.lastname: Sun
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D049109:Cell Proliferation; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D015999:Multivariate Analysis; D011379:Prognosis; D013869:Thiolester Hydrolases / Q000378:metabolism*; D016896:Treatment Outcome; D014410:Tumor Stem Cell Assay; D043222:Ubiquitin Thiolesterase; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D013869:Thiolester Hydrolases; D043222:Ubiquitin Thiolesterase; C527170:Usp22 protein, human