Cytotoxic effects of colicins E1 and E3 on v-myb-transformed chicken monoblasts

Colicins show a considerable cytostatic activity, which is much less known and understood than their killing activity targeting bacteria of the Entero bacteriaceae family. In this communication, the cytotoxic effects of colici ns E1 and E3 on v-myb-transformed chicken monoblasts BM2 are presented. We detected clear reduction of the viable cell number induced by colicins E1 a nd E3, occurring without apparent changes in cell cycle profiles. The level of inhibition was proportional to the colicin concentration within the lim its of 0.5-1.25 mug/ml. This result documents that colicins produced by Ent erobacteriaceae exert their cytotoxic effects on leukemic cells.