Induction of sister chromatid exchanges and cell division delays in human lymphocytes by the anti-tumour agent homo-aza-steroidal ester of p-bis(2-chloroethyl)aminophenoxy acetic acid.

3 beta-Hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17-oic-13,17-lactam-p-bis(2-chloroethyl) aminophenoxyacetate (NSC 294859) is a new modified steroidal alkylating agent. This compound was given by i.p. administration to mice bearing different types of tumour. It was found to exhibit good activity in L1210 and P388 leukaemias with maintenance of activity against advanced tumours. The treatment of colon 26 tumour and B16 melanoma resulted in positive antineoplastic activity. The drug was not shown to be active in a melphalan-resistant P388 line. In this study, NSC 294859 was found to be effective in causing statistically significant increases in sister-chromatid exchange (SCE) rates and cell division delays. The alkylating agent component, p-bis-(2-chloroethyl)aminophenoxy acetic acid, was shown to be less effective than the parent compound, while the modified steroid component, 3 beta-hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17-oic-13,17-lactam, showed no effect. There were no statistically significant differences among donors regarding the induction of SCEs and replication indices (RIs) for the compounds tested.