In vivo molecular targeting effects of anti-Sp17- ICG-Der-02 on hepatocellular carcinoma evaluated by an optical imaging system

Background: as the expression of human sperm protein 17 (sp17) in normal tissue is limited and the function is obscure,its aberrant expression in malignant tumors makes it to be a candidated molecular marker for tumor imaging diagnosis and targeting therapy of the diseases.the aim of this research is to evaluate the targeting effects of anti-sperm protein 17 monoclonal antibody (anti-sp17) on cancer in vivo and investigate its usefulness as a reagent for molecular imaging diagnosis. methods. immunohistochemistry was used to identify the expression of sp17 in a hepatocellular carcinoma cell line and tumor xenograft specimens. a near infrared fluorescence dye,icg-der-02,was covalently linked to anti-sp17 for in vivo imaging. the immuno-activity of the anti-sp17-icg-der-02 complex was tested in vitro by elisa; it was then injected into tumor-bearing nude mice through the caudal vein to evaluate its tumor targeting effect by near infrared imaging system. results: overexpression of sp17 on the surface of the hepatocellular carcinoma cell line smmc-7721 was demonstrated. anti-sp17-icg-der-02 with immuno-activity was successfully synthesized. the immuno-activity and photo stability of anti-sp17- icg-der-02 showed good targeting capability for sp17 expressing tumor models (smmc-7721) in vivo,and its accumulation in the tumor lasted for at least 7 days. conclusions: anti-sp17 antibody targeted and accumulated in sp17 positive tumors in vivo,which demonstrated its capability of serving as a diagnostic reagent. © 2011 li et al; licensee biomed central ltd.