Proteomics-based identification of haptoglobin as a novel plasma biomarker in oral squamous cell carcinoma

Background: Identification of tumor biomarkers to assist early diagnosis and monitoring of disease progression may potentially decrease the mortality and morbidity associated with oral cancer Methods A mouse model with oral squamous cell carcinoma (OSCC) induced by 4-nitroquinoline 1-oxide (4-NQO)/arecoline in drinking water was established to discover stage-associated biomarkers A proteomics approach. immunoblot and immunohistochemical analysis were used to validate the expressed biomarkers in mice with OSCC Human plasma samples were also collected and candidate biomarkers were evaluated using enzyme-linked immunosorbent assay. Results. Proteomic profiling of mouse plasma samples indicated that haptoglobin and apolipoprotein A1 precursor were up-regulated in the mice with OSCC. Immunoblotting of plasma samples and immunohistochemical analysis of oral tissues showed a significantly higher level of haptoglobin in the OSCC mice than in the control mice The expression of haptoglobin in human plasma samples from 52 patients with OSCC indicated a strong correlation between the increasing levels of haptoglobin and the clinical stages of OSCC (P<0 01) Conclusions These results suggest that haptoglobin has a great potential as a sensitive plasma biomarker for early detection of patients with OSCC Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved