Cellular processing of I-125- and In-111-labeled epidermal growth factor (EGF) bound to cultured A431 tumor cells

Low molecular weight of epidermal growth factor (EGF) enables better intrat umoral penetration in comparison with larger targeting proteins, but the ce llular retention of EGF-associated radioactivity is poor for directly iodin ated EGF. An attempt was made to improve intracellular retention by the use of metal-diethylenetriaminepentaacetic acid or nonphenolic linker (N-succi nimidyl-para-iodobenzoate) as labeling agents. The use of nonphenolic linke r did not improve retention of the radioactivity in A431 carcinoma cell lin e. The use of the radiometal label provided an appreciable prolongation of radioactivity residence inside the cell. NUCL MED BIOL 27;8:827-835, 2000. (C) 2000 Elsevier Science Inc. All rights reserved.