The incorporation of 9-beta-D-arabinofuranosyl-2-fluoroadenine (F-ara-A) into HL-60 cellular nucleic acids was monitored by cesium sulfate gradient centrifugation. The results demonstrated that F-ara-A incorporated into both RNA and DNA. These findings are in contrast to those previously obtained with 1-beta-D-arabinofuranosylcytosine (ara-C) and 9-beta-arabinofuranosyladenine (ara-A) which demonstrated incorporation of these nucleosides only in DNA. F-ara-A inhibited HL-60 proliferation, and the incorporation of F-ara-A into both DNA and RNA correlated with loss of clonogenic survival. Furthermore, cytostatic concentrations of F-ara-A resulted in the appearance of a more mature phenotype, a finding consistent with the effects of other inhibitors of DNA synthesis VSports手机版. The incorporation of F-ara-A into RNA and DNA should provide new insights regarding the mechanism of action of this agent. .