INDUCTION OF CHROMOSOMAL-ABERRATIONS IN HUMAN-LYMPHOCYTES BY THE ANTITUMOR ALKYLATING AGENT HOMO-AZA-STEROIDAL ESTER OF P-BIS(2-CHLOROETHL)AMINOPHENOXY ACETIC-ACID, IN-VITRO

The clastogenic activity of the antineoplastic alkylating agent 17-sec o-5alpha-androstan-17-oic-13,17-lactam-p-bis (2-chloroethyl) aminophen oxy acetic acid (NSC 294859) and its congeners was studied in human ly mphocyte cultures in vitro. Cells were exposed to several concentratio ns of the drugs for 24 h. It was found that NSC 294859 reduces the mit otic index and causes chromosome- as well as chromatid-type aberration s in a dose-dependent way. From its congeners, the alkylating agent (p -bis (2-chloroethyl) aminophenoxy acetic acid) induces the same phenom ena but to a lesser extent, while the modified steroid o-13,17-seco-5a lpha-androstan-17-oic-13,17-lactam) causes cytogenetic damages at the control level. These results favour the assumption that the antitumour activity of NSC 294859 is mainly based on its cytogenetic effects.