UP-REGULATED EXPRESSION OF THE GENES ENCODING TRANSLATION INITIATION-FACTORS EIF-4E AND EIF-2-ALPHA IN TRANSFORMED-CELLS

Increased protein synthesis is necessary for the transition of cells f rom quiescence to proliferation. It is shown in this paper that the in duction of expression of the translation initiation factor eIF-4E in n ormal cells requires serum growth factors, while this requirement is a brogated in tumor cells analyzed in this study. Further, the expressio n of eIF-4E and eIF-2 alpha is increased in c-myc, v-src, and v-abl-tr ansformed cells. It is demonstrated that an increase in c-myc function leads to elevated expression of eIF-4E and eIF-2 alpha, increases in net protein synthesis and cell proliferation. It mag be suggested that constitutive activation of translational machinery may be one common mechanism by which various oncogenes exert their transforming function .