title: Association of OPN overexpression with tumor stage, differentiation, metastasis and tumor progression in human laryngeal squamous cell carcinoma.
abstract: BACKGROUND
  Osteopontin (OPN) is overexpressed in many human tumors and involved in promotion of cancer cells by regulating various facets of tumor progression such as cell proliferation, invasion and metastasis. To understand roles of OPN in tumor progression of laryngeal squamous cell carcinoma (LSCC) or develop molecular marker for prognosis and treatment of LSCC, we thus explore biological function of OPN and correlation with p53 in LSCC.
  
  
  METHODS
  The expression of OPN and p53 in tumor tissues of LSCC was determined immunohistochemically in both LSCC and adjacent normal tissues. Lentivirus vector with RNAi small hairpin gene sequence of OPN (named LV-shOPN) was transfected into Hep-2 cells. OPN expression was detected by Western blotting assay and the viability and invasive ability of Hep-2 cells were examined by MTS and transwell assay.
  
  
  RESULTS
  We found that OPN and p53 protein expressions were significantly higher in LSCC tumor tissues than adjacent normal tissues (76.2% vs. 23.8% for OPN and 63.8% vs. 15.2% for p53, all P < 0.001). OPN expression was also significantly correlated with p53 expression, tumor stage, grade and the presence of lymph node. The constructed LV-shOPN effectively inhibited the OPN expression, viability and invasive ability of Hep-2 cells (all P < 0.050).
  
  
  CONCLUSIONS
  Taken together, OPN is overexpressed in LSCC. OPN expression is correlated with p53 expression, tumor progression and lymph node metastasis. Additionally, RNAi silencing of OPN expression can significantly inhibit tumor viability and invasion ability of Hep-2 cells. Thus, OPN may be considered as a marker and potential gene targeting therapy in LSCC.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, General Hospital of Jinan Military Command Jinan 250031, Shandong Province, China.
authors.forename: Jianqiu
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, General Hospital of Jinan Military Command Jinan 250031, Shandong Province, China.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, General Hospital of Jinan Military Command Jinan 250031, Shandong Province, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command Jinan 250031, Shandong Province, China.
authors.forename: Min
authors.initials: M
authors.lastname: Geng
authors.affiliation: Department of Head and Neck Surgery, U.T. M.D. Anderson Cancer Center Houston, TX 77030, USA.
authors.forename: Guojun
authors.initials: G
authors.lastname: Li
authors.affiliation: Radiology Department of Shanghai Ninth People's Hospital Affiliated Shanghai Jiaotong University School of Medicine Shanghai, 200011, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tao
authors.affiliation: Department of General Surgery, Hebei General Hospital Shijiazhuang, Hebei 050051, China.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Zhang
keywords: Osteopontin; RNA interference; laryngeal squamous cell carcinoma; p53