title: Identification and verification of Hsp90-beta as a potential serum biomarker for lung cancer.
abstract: BACKGROUND
  Hsp90-beta was investigated as prognostic factor because of its apparent association with tumorigenesis. The aim of this study was to investigate the expression of Hsp90-beta in lung cancer patients, to analyze the relationship with respect to the clinicopathological features and to assess whether Hsp90-beta as a potential serum marker for lung cancer.
  
  
  METHODS
  Expression of Hsp90-beta was examined using immunohistochemistry, in-situ hybridization, western blot and enzyme-linked immunosorbent assay. Sensitivities and specificities for Hsp90-beta serum test were determined using receiver operator characteristic curve and cutoff was defined based on 95% and 85% sensitivities.
  
  
  RESULTS
  Lung cancer tissues exhibited higher expression of Hsp90-beta than the normal tissues (P < 0.05) and the serum Hsp90-beta of lung cancer patients also exhibited higher level than control groups (P < 0.05). Moreover, increased serum Hsp90-beta was significantly associated with the pathological grade and clinical stage of lung cancer patients (P < 0.05). Using receiver operator characteristic curve analysis, the cutoffs for distinguishing lung cancer from normal and benign groups were 1.155 and 1.158 ng/ml respectively. The sensitivities of Hsp90-beta for distinguishing lung cancer from normal and benign groups were 98.77% and 95.9%, and specificities were 88.33% and 72.7%.
  
  
  CONCLUSIONS
  Up-regulation of serum Hsp90-beta was associated with pathological grade and clinical stage of lung cancer patients, which indicated that it could be considered molecular biomarker for diagnosis and prognosis of lung cancer.
authors.affiliation: Department of Respiratory Medicine, Second Affiliated Hospital, Xi'an Jiaotong University Xi'an, China.
authors.forename: Biaoxue
authors.initials: B
authors.lastname: Rong
authors.affiliation: Department of Neurology, Lanzhou University Second Hospital Lanzhou, China.
authors.forename: Chongchong
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Department of Respiratory Medicine, Gansu Provincial People's Hospital Lanzhou, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Respiratory Medicine, Second Affiliated Hospital, Xi'an Jiaotong University Xi'an, China.
authors.forename: Zongjuan
authors.initials: Z
authors.lastname: Ming
authors.affiliation: Department of Respiratory Medicine, Gansu Provincial People's Hospital Lanzhou, China.
authors.forename: Xiguang
authors.initials: X
authors.lastname: Cai
authors.affiliation: Departments of Statistics and Epidemiology, Medical College, Lanzhou University Lanzhou, China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Gao
authors.affiliation: Department of Respiratory Medicine, Second Affiliated Hospital, Xi'an Jiaotong University Xi'an, China.
authors.forename: Shuanying
authors.initials: S
authors.lastname: Yang
keywords: Hsp90-beta; Lung cancer; biomarker; diagnosis; serum