CROSS-LINKING OF DNA IN L1210 CELLS AND NUCLEI TREATED WITH CYCLOPHOSPHAMIDE AND PHOSPHORAMIDE MUSTARD

  • 1 January 1978
    • journal article
    • research article
    • Vol. 62  (1) , 23-29
Abstract
Phosphoramide mustard, formed from cyclophosphamide in vivo and in vitro, may be the active metabolite of this drug. Phosphoramide mustard was at least 100 times more potent than cyclophosphamide in inhibiting growth of 2 strains [LM4 and LS2] of the L1210 lymphoma [mouse] in culture. Phosphoramide mustard also produced enlargement of cells, an effect not seen with cyclophosphamide. Phosphoramide mustard significantly increased the amount of cross-linked DNA after incubation with intact LM4 cells or nuclei isolated from these cells. Cyclophosphamide had a similar effect only in the isolated nuclei. These findings strengthen the proposed role of phosphoramide mustard as the active metabolite of cyclophosphamide. The effect of cyclophosphamide on nuclei is unexplained.