EVALUATION OF LAMININ PEPTIDE-FRAGMENTS LABELED WITH IN-111 FOR THE POTENTIAL IMAGING OF MALIGNANT-TUMORS

The laminin peptide fragments GYIGSR-NH2 and CDPGYIGSR-NH2 are known t o bind to a 67-kDa laminin receptor. This receptor is understood to be expressed at higher than normal levels in malignant tumor cells, part icularly those of breast and colon carcinomas. Peptides DTPA-GYIGSR-NH 2 (1), DTPA-(GYIGSR-NH2)(2) (2), DTPA-CDPGYIGSR-NH2 (3), DTPA-(CDPGYIG SR-NH2)(2) (4), and negative control DTPA-GAGAGA-NH2 (5) were prepared by solid-phase peptide synthesis. AU five DTPA-conjugated peptides we re subsequently radiolabeled with In-111 and their tissue distribution evaluated in mice bearing C3H tumors, In-111-3 and In-111-4 showed th e highest specific tumor localization. These preliminary data support father study of radiolabeled peptide fragments fur the potential detec tion of malignant tumors of the breast and other organs. (C) Munksgaar d 1997.