DIFFERENTIAL TRANSFERRIN RECEPTOR DENSITY IN HUMAN COLORECTAL-CANCER - A POTENTIAL PROBE FOR DIAGNOSIS AND THERAPY

Transferrin receptor density was investigated in human colorectal surg ical specimens. Crude membranes were prepared from 23 cancer tumors (a denocarcinoma or malignant villous tumor) and 3 non-cancer tumors (pol yadenoma or villous tumor) and 26 adjacent control mucosa. Contrary to non-cancer tumors. Scatchard analysis of I-125-transferrin binding da ta evidenced higher maximal transferrin binding capacity and lower dis sociation constant in cancer tissues (B-max cancer 1.828 +/- 0.320 nmo l/g, K-d 24.1 +/- 4.7 nM, as compared to paired control colonic mucosa (B-max contol 0.851+/-0.182 nmol/g, K-d 30.7+/-7.3 nM), paired t-test s: B-max p<0.001, K-d p<0.05). As the cancer/control B-max ratio was 2 .6 +/- 0.41 transferrin carrier constructs should be proposed for canc er imaging or therapy.