Apoptosis induced by modified ribonucleosides in human cell culture systems

The in vitro modulation of apoptosis and cell proliferation by modified in comparison with non-modified ribonucleosides was investigated for the first time using peripheral blood lymphocytes, HL-60 cells and Caco-2 cells as human cell culture models. Modulating effects of several ribonucleosides were found in the range of 10(-7)-10(-3) mol/l. The following ribonucleosides induced significant apoptosis of HL-60 cells: adenosine, N-6-dimethyladenosine, N-6-(2-isopentenyl)-adenosine, N-2-dimethylguanosine. A significant apoptotic effect on PBL was found with N-6-dimethyladenosine and N-6-(2-isopentenyl)-adenosine. N-6-Dimethyladenosine, N-6-(2-isopentenyl)-adenosine and guanosine had a pronounced inhibitory effect on Caco-2 cell apoptosis, Regarding the known function of ribonucleosides as pathobiochemical marker molecules for cancer, the possibility of a selective apoptotic effect against malignant cells is discussed. (C) 1998 Federation of European Biochemical Societies.