Ornithine decarboxylase--a predictor for tumor chemosensitivity.

The activity of ornithine decarboxylase (ODC) was determined in P388 murine leukemia cells treated with adriamycin (ADR) and methotrexate (MTX). Some of the cell lines were resistant to ADR, MTX or their combinations. A similar pattern was found between the cytotoxicity and the suppression of ODC activity in these cell lines in terms of drug concentrations.