m-Iodobenzylguanidine (MIBG) is an analogue of norepinephrine with anticancer activity. It inhibits cell growth in a panel of human and mouse leukemia, fibrosarcoma, melanoma, and neuroblastoma cell lines when used at a concentration of 20 μg/ml and reduces clonogenic survival of L1210 leukemia cells in a concentration-dependent manner. MIBG increases survival in N1E155 and L1210 mouse xenograft models when administered at doses of 40 and 20 mg/kg, respectively. It selectively accumulates in chromaffin tissues and tumors and formulations containing radiolabeled forms of MIBG have been used as imaging agents in the diagnosis and treatment of neuroendocrine tumors. MIBG also inhibits ADP-ribose linkage to membrane proteins in turkey erythrocyte membranes.
