Shiga toxin B-subunit as a vector for tumor diagnosis and drug delivery to GB₃ expressing tumors

摘要

The invention relates to new compounds for cancer therapy or diagnosis and more specifically to the use of a non-toxic B subunit of Shiga toxin mutant as a vector for diagnostic products or drugs in over-expressing Gb₃ receptor cells, such compounds having the following formula: STxB-Z(n)-Cys-Y(m)-T whereinSTxB is the Shiga Toxin B subunit or a functional equivalent thereof,Z(n) wherein n is 0 or 1 and when n is 1, Z is an amino-acid residue devoid of sulfydryl group, or is a polypeptide,Cys is the amino-acid residue for Cysteine,T is a molecule linked by a covalent bound to the S part of Cys, selected in a group comprising: agents for in vivo diagnosis,cytotoxic agents,prodrugs, orenzymes for the conversion of a prodrug to a drug,Y(m) wherein m is 0 or 1 and when m is 1, Y is a linker between T and Cys, said linker being either cleavable or not cleavable for the release of T after the internalization of the hybrid compound into said cells.