title: Identification of Apo-A1 as a biomarker for early diagnosis of bladder transitional cell carcinoma.
abstract: BACKGROUND
  Bladder transitional cell carcinoma (BTCC) is the fourth most frequent neoplasia in men, clinically characterized by high recurrent rates and poor prognosis. Availability of urinary tumor biomarkers represents a convenient alternative for early detection and disease surveillance because of its direct contact with the tumor and sample accessibility.
  
  
  RESULTS
  We tested urine samples from healthy volunteers and patients with low malignant or aggressive BTCC to identify potential biomarkers for early detection of BTCC by two-dimensional electrophoresis (2-DE) coupled with mass spectrometry (MS) and bioinformatics analysis. We observed increased expression of five proteins, including fibrinogen (Fb), lactate dehydrogenase B (LDHB), apolipoprotein-A1 (Apo-A1), clusterin (CLU) and haptoglobin (Hp), which were increased in urine samples of patients with low malignant or aggressive bladder cancer. Further analysis of urine samples of aggressive BTCC showed significant increase in Apo-A1 expression compared to low malignant BTCC. Apo-A1 level was measured quantitatively using enzyme-linked immunosorbent assay (ELISA) and was suggested to provide diagnostic utility to distinguish patients with bladder cancer from controls at 18.22 ng/ml, and distinguish patients with low malignant BTCC from patients with aggressive BTCC in two-tie grading system at 29.86 ng/ml respectively. Further validation assay showed that Apo-A1 could be used as a biomarker to diagnosis BTCC with a sensitivity and specificity of 91.6% and 85.7% respectively, and classify BTCC in two-tie grading system with a sensitivity and specificity of 83.7% and 89.7% respectively.
  
  
  CONCLUSIONS
  Taken together, our findings suggest Apo-A1 could be a potential biomarker related with early diagnosis and classification in two-tie grading system for bladder cancer.
authors.affiliation: Department of Pathophysiology, HeBei United University, Tangshan, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Li
authors.affiliation: Research Laboratory for Tumor Immunity of Tianjin Urological Institute, Second Hospital of Tianjin Medical University, Tianjin, China.
authors.forename: Changying
authors.initials: C
authors.lastname: Li
authors.affiliation: Tianjin Key Laboratory of Biomarkers for Occupational and Environmental Hazard of Chinese People's Armed Police Forces Medical College, Tianjin, China.
authors.forename: Huili
authors.initials: H
authors.lastname: Wu
authors.affiliation: Research Laboratory for Tumor Immunity of Tianjin Urological Institute, Second Hospital of Tianjin Medical University, Tianjin, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Research Laboratory for Tumor Immunity of Tianjin Urological Institute, Second Hospital of Tianjin Medical University, Tianjin, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Tianjin Key Laboratory of Biomarkers for Occupational and Environmental Hazard of Chinese People's Armed Police Forces Medical College, Tianjin, China.
authors.forename: Shixin
authors.initials: S
authors.lastname: Wang
authors.affiliation: Research Laboratory for Tumor Immunity of Tianjin Urological Institute, Second Hospital of Tianjin Medical University, Tianjin, China.
authors.forename: Jiwu
authors.initials: J
authors.lastname: Chang