The combination of a proapoptotic peptide with covalent tagging and a carrier-Ru-complex inhibited tumor growth in mice after a single injection.

In the field of molecular imaging, selectivity for target cells is a key determinant of the degree of imaging contrast. Previously, we developed a pre-targeted method by which target cells could be selectively imaged using a labeled N-glycan that was ligated in situ with an integrintargeted cyclic RGD peptide on the cell surface. Here we demonstrate the power of our method in discriminating various cancerous and non-cancerous cells that cannot be distinguished using conventional RGD ligands. Using four cyclic RGDyK peptides with various linker lengths with five N-glycans, we identify optimal combinations to discriminate six types of α v β 3 integrin-expressing cells on 96-well plates. The optimal combinations of RGD and Nglycan ligands for the target cells are fingerprinted on the plates, and then used to selectively image tumors in xenografted mouse models. Using this method, various N-glycan molecules, even those with millimolar affinities for their cognate lectins, could be used for selective cancer cell differentiation.

We developed 211At-radiolabeled 2,6-diisopropylphenyl azide (ADIPA) for targeted α-particle therapy. In the experiment using a mouse model, low-dose (70 kBq) administration of ADIPA effectively suppressed tumor growth without causing adverse effects.