Azidothymidine

Materials. The following chemicals and reagents were obtained from the indicated companies: Dulbecco's modified Eagle's medium (DMEM), from GIBCO BRL, Grand Island, NY, USA; fetal bovine serum (FBS), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), doxorubicin, azidothymidine, 2',3'-dideoxycytidine from Sigma-Aldrich Inc., St. Louis, MO, USA; dimethyl sulfoxide (DMSO), dextran sulfate (molecular mass, 5 kDa) from Wako Pure Chem. Ind., Osaka, Japan; methotrexate from Nacalai Tesque, Inc., Kyoto, Japan; curdlan sulfate (molecular mass: 79 kDa) from Ajinomoto Co. Ltd., Tokyo, Japan. Culture plastic dishes and plates (96-well) were purchased from Becton Dickinson (Franklin Lakes, NJ, USA). 12), (2E)-1-(4-methoxyphenyl)-3-(4-methoxyphenyl)-2-propen-1-one ( 13), (2E)-3-(2,4-dimethoxyphenyl)-1-(4methoxyphenyl)-2-propen-1-one ( 14), (2E)-1-(2,4-dimethoxyphenyl)-3-(4-methoxyphenyl)-2-propen-1-one (15) (structures shown in Figure 1) were synthesized by base-catalyzed condensation of the appropriate acetophenone with selected benzaldehyde derivatives according to previous methods (17) . All compounds were dissolved in DMSO at 40 mM and stored at -20˚C before use.

Park Memorial Institute 1640 medium (Sigma) with 10% heat-inactivated foetal bovine serum (Sigma), penicillin (100 U/mL) and streptomycin (100 µg/mL). To maintain HIV-1 latency in ACH-2 cells, 20 μM azidothymidine (Sigma) was added to the culture medium but was excluded prior to conducting the experiments. The cells (2.0 × 10 6 cells/2.0 mL medium/well) were treated with butyric acid. HeLa cells and TZM-bl cells, a HeLa-derived cell line expressing surface CD4, CXCR4 and CCR5 containing a chromatinintegrated HIV-1 LTR [24, 25] were grown at 37°C in Dulbecco's modified Eagle's medium (Sigma) with 10% heat-inactivated foetal bovine serum.