APOPTOSIS IS REGULATED BY THE RATE OF GLUCOSE-TRANSPORT IN AN INTERLEUKIN-3 DEPENDENT CELL-LINE

In the absence of a survival stimulus, the interleukin 3 (IL-3)-depend ent IC.DP cell line undergoes a process termed programmed cell death o r apoptosis. Survival can be induced by IL-3, which can also stimulate proliferation of IC.DP cells. IC.DP cells have been stably transfecte d with the p160(v)-(abl) protein tyrosine kinase, activation of the ki nase at the permissive temperature permits cell survival in the absenc e of IL-3 by suppression of apoptosis, although the growth factor is s till required for proliferation. Both IL-3 and activation of the v-ABL tyrosine kinase stimulated glucose transport, which may in part be du e to a translocation of transporters to the cell surface. Inhibition o f glucose uptake markedly increased the rate of apoptosis in these cel ls, an effect that could be reversed by the provision of alternative e nergy sources such as glutamine. Growth factor- or oncogene-mediated i ncreases in glucose uptake may therefore represent an important regula tory point in the suppression of apoptosis.