Distinct inhibitory effects of 2-chloro-2 '-deoxyadenosine and 9-beta-D-arabinosyl-2-fluoroadenine on DNA methyltransferase in human T-lymphocytes

The effect of 2-chloro-2'-deoxyadenosine and 9-beta-D-arabinosyl-2-fluoroad enine on DNA methyltransferase activity in stimulated human T-lymphocytes w as estimated. In comparative studies 5-aza-deoxycytidine and deoxyadenosine plus deoxycoformycin were used. These antileukemic compounds demonstrated different effects; both 2CdA and dAdo plus dCF, like 5-aza-dCyt, inhibited the enzyme activity by 85-90% after 72 hours activation of lymphocytes, whi le the effect of F-ara-A, under the same conditions, was insignificant.