Stimulation of growth in human and murine cells by adriamycin.

Adriamycin causes a variety of biological actions and is an effective cytotoxic agent against proliferating cells. In this paper we show that the drug is not limited in its action solely to cytotoxicity, but can also stimulate cell growth under the appropriate conditions. Using the survival assay of cloning in soft agar, we present data showing that the conditions for Adriamycin-induced growth stimulation are that the drug be in a subtoxic concentration range of 10(-10)-10(-9) M (greater than 10(-8) M causes cytotoxicity) and that the growth medium be suboptimal. This latter condition is satisfied by either growing cells for an extended period in order to exhaust the growth supporting capacity of the medium, or by growing the cells at low (less than 10%) serum concentrations. Several active anthracycline congeners also have the ability to stimulate growth. The results indicate that the cytotoxic anticancer agent Adriamycin can stimulate the proliferation of some cells.