INVITRO AND INVIVO EFFECTS OF RIBONUCLEASES ON CELLULAR-CYCLE DYNAMICS IN TUMOR-CELLS

The effects of RNAase from Bacteroides intermedius and pancreatic RNAase on the dynamics of cellular cycle phases were studied in the cells of ascitic lympholeukemia NK/Ly in vivo and in vitro, in the cells of the human ovary carcinoma CaOv and in the cells of ascitic leukemia P388 in vivo. It was shown that both the RNAases induced cell accumulation (blocking) in the G2/M Phase of a cellular cycle with simultaneous certain depletion of the proportion of DNA-synthesizing cells (S-phase). In in vitro experiments, there was a higher efficiency of pancreatic RNAase. In animal experiments, RNAase from B. intermedius was more efficient. The likely target of the in vitro and in vivo effects of the enzymes on the cellular cycle dynamics and biological activity are discussed.