THE CHARACTERIZATION OF CELL-DEATH INDUCED BY 1-(3-C-ETHYNYL-BETA-D-RIBO-PENTOFURANOSYL)CYTOSINE (ECYD) IN FM3A CELLS

The characterization of cell death induced by 1-(3-C-ethynyl-beta-D-ri bo-pentofuranosyl)cytosine (ECyd), a potent inhibitor of RNA synthesis , was performed using mouse mammary tumor FM3A cells in vitro. Accompa nied with the cell death induced by ECyd (3.0 mu M)-treatment, about 1 00-200 kbp-sized and internucleosomal DNA fragmentation were observed by orthogonal-field-alternation gel electrophoresis (OFAGE) and conven tional gel electrophoresis, respectively. Protease inhibitors, carbobe nzoxy-L-aspart-1-yl[(2, 6-dichlorobenzoyl)oxy]methane (Z-Asp-CH2-DCB), N alpha-tosyl-p-lysine-L-lysine chloromethyl ketone (TLCK) and N-p-to syl-L-phenylalanine chloromethyl ketone (TPCK), effectively blocked th e cell death, suggesting that the proteases inhibited by Z-Asp-CH2-DCB , TLCK or TPCK were involved in the process of the cell death.