[Binase possesses a selective cytotoxic action on kit-transformed precursors of myeloid cells]

The effect of cationic microbial ribonuclease from Bacillus intermedius (binase) on normal precursors of myeloid cells of FDC-P1 mice and kit-transformed precursors expressing the receptor of the growth factor of stem cells has been studied by flow-through cytometry. Selective apoptogenic properties of binase toward kit-transformed cells were revealed. Viable kit-transformed cells responded to binase by an increase in the concentration of cytosolic calcium. The content of calcium in the cytosol of both cell types in which apoptosis was induced by binase decreased in a dose-dependent manner. The death of cells was not accompanied by a substantial decrease in the content of intracellular RNA. A possible mechanism of binase-induced effects, which involves changes in the expression of genes due to the interference of exogenous RNAse into the RNA interference, was considered.