Antibody-mediated targeting of differentiation inducers to tumor cells: inhibition of colonic cancer cell growth in vitro and in vivo. A preliminary note

A differentiation inducer (sodium butyrate) encapsulated in liposomes that are in turn covalently linked to anti-Lex monoclonal antibody, SH1 (IgG3 isotype), was successfully targeted to human colonic adenocarcinoma HRT-18 and HT29 cells expressing Lex antigen in vitro as well as in vivo in athymic nu/nu mice. Tumor cell growth was significantly inhibited and was associated with changes in cell morphology and increases in membrane-bound alkaline phosphatase and gamma-glutamyltranspeptidase, indicating the occurrence of butyrate-induced differentiation.