Development and validation of H11B2C2 monoclonal antibody-reactive hyaluronic acid binding protein: overexpression of HABP during human tumor progression.

Informative biomarkers of tumor progression have been elusive. The interaction between hyaluronic acid (HA) and its binding proteins (HABP) plays a pivotal role during malignancy. In the present study, we have developed a monoclonal antibody (mAb, termed as H11B2C2 mAb) and showed that this mAb specifically reacts with overexpressed HABP from a wide variety of malignant tumors as compared with benign tumors. In Western blot analysis, H11B2C2 mAb detected a major 80-kDa protein from human cancer cell lines, and the overexpression of 55-57- and 30-kDa proteins in malignant tumors compared with benign tumors. Furthermore, immunohistochemical analysis of different types of benign and malignant tumors with different grades showed higher expression of HABP in all the malignant tumors when compared with the benign tumors. HABP overexpression was specific to tumor cells when compared with the surrounding stroma and localized on the cell surface as well as in the intracellular region. The competitive inhibition experiments using HA polymer and its oligosaccharides in the Western blot and immunohistopathology experiments suggested that the H11B2C2 mAb-reactive protein is HABP. Altogether, the present study showed overexpression of the H11B2C2 mAb-reactive HABP in various malignant tumors as compared with benign tumors. Thus, H11B2C2 mAb-reactive HABP can be used as a potential biomarker during tumor progression.