Cellular aspects of the action of cytosine arabinoside

The cellular effects of Ara-C are reviewed including its S-phase sensitivity, its proliferative-dependent cytotoxicity and progression delay effects which result in unbalance growth. Both direct and indirect cytotoxic mechanisms are discussed. The impact of such cellular information on the scheduling of Ara-C is presented with regard to normal and tumor cell population cytotoxicity. Based on these data a therapeutic rationale is presented.