Response of Transplantable Tumors in Mice and of Macromolecular Synthesis to 17β-Acetamido-3-aza-A-homo-4α-androsten-4-one

Abstract

17β-acetamido-3-aza-A-homo-4α-androsten-4-one has cytostatic activity against Ehrlich ascites tumor, 11210, and P388 leukemias in mice when administered in-traperitoneally. The effect of the homo-aza-steroid on the incorporation of radioactive precursors to DNA and RNA of 12210 leukemia cells was investigated. It was found that treatment of cells with 12.5 fig/ml of the drug for I hour inhibited DNA synthesis by 81%. This was partly because the drug affected the radioactive thymidine pool in the cell. The inhibitory effect was found to be reversable. The incorporation of [³H]thymidine into DNA was lower when cells were incubated in the presence of S9 mix. It was also found that the same compound inhibited RNA synthesis by 67%.