INHIBITORY EFFECT OF A NUCLEOSIDE ANALOG, ACYCLOVIR, ON LEUKEMIA-CELLS

Acyclovir (ACV), a nucleoside analog, has been demonstrated previously to suppress selectively the proliferation of NIH3T3 fibroblastic cell s transformed by either v-abl or bcr-abl gene transfection. From a vie wpoint of clinical application of ACV, we investigated whether ACV inh ibited the growth of leukemia cells expressing either p210(BCR-ABL) or p185(BCR-ABL). Acyclovir exerted an inhibitory effect on OM9;22 cells , p185(BCR-ABL) expressing cells, in a dose-dependent manner. Despite no down-modulation of a BCR-ABL tyrosine kinase activity or its expres sion was observed after treatment with ACV, cell cycle analysis demons trated synchronization of OM9;22 cells at the G0/G1 phase. This sugges ts that, although ACV does not directly act on BCR-ABL tyrosine kinase , ACV may exert its inhibitory effect on some leukemia cell lines via alterations of the cell cycle. Although selective inhibition of Philad elphia chromosome-positive leukemia cell growth was not apparent, our data provides a therapeutic possibility for ACV in the treatment for l eukemia. Copyright (C) 1996 Elsevier Science Ltd.