Synergistic effect of cis-dichlorodiammineplatinum and 5-aza-2'-deoxycytidine on mouse leukemic cells in vivo and in vitro.

cis-Dichlorodiammineplatinum and 5-aza-2'-deoxycytidine display a considerable synergistic effect in L1210 and La mouse leukemia in vivo; the combination of both drugs is also clearly synergistic in vitro as evidenced by the effects on cell growth and cell survival in soft-agar medium. In exponential but not in stationary growth of L1210 cells, the drugs interfere with DNA and RNA synthesis.