Effects of 9,10-Anthracenedione, 1,4-bis[[2-[(2-hydroxyethyl)amino]-ethyl]amino]-, diacetate on Cell Morphology and Nucleic Acids of Friend Leukemia Cells<xref ref-type="fn" rid="FN2">2</xref>

Abstract

Treatment of Friend leukemia cells for 18 hours with 9,10-anthracenedione, 1,4-bis[[(2-hydroxyethyl)amino]ethyl]amino]-, diacetate (ANT) at concentrations up to 1.0 microgram/ml induced significant changes in cell metabolism and structure. Alterations in cell nucleic acid content were detected in cells stained with acridine orange under conditions such that DNA and RNA contents could be measured simultaneously by flow cytometry. Cells treated for 18 hours with ANT at concentrations of 0.05-0.1 microgram/ml became partially blocked at the G2 phase. In addition, about 30% of the cells became polyploid and demonstrated diplochromosomes at the 8C level of mitosis. The nuclear chromatin of blocked cells had an altered structure as reflected by a change in sensitivity of DNA in situ to denaturation induced by low pH. All viable cells treated with ANT for 18 hours at concentrations of 0.4-1.0 microgram/ml were blocked in G2 phase. These cells had significantly more RNA than did untreated cells. Transmission electron microscopic observations of thin-sectioned cells suggested that this increased RNA content in ANT-treated cells was mostly due to an approximately 50% increased cell diameter and partly due to a disproportionate increase in nucleolar size. In addition, electron microscopy revealed that ANT caused increased chromatin condensation and granulation. The drug had no apparent effect on production of the endogenous Friend murine leukemia virus.