Suppression of v- src Transformation by the drs Gene

Abstract

ABSTRACT Previously, we isolated a novel gene, drs , which was downregulated by retroviral oncogenes such as v- src and v-K- ras , from a cDNA library of primary rat embryo fibroblasts. Experiments using a temperature-sensitive mutant of the v- src gene indicated that downregulation of drs mRNA was dependent on functional expression of v-Src. In addition, expression of drs mRNA was also reduced by serum stimulation of G 0 -arrested normal rat fibroblast cells. To clarify the function of the drs gene in cell transformation and proliferation, we introduced drs linked to a potent promoter into a normal rat cell line, F2408, and examined the effect of ectopic expression of exogenous drs on the transformation by the v- src gene and growth properties. Cells expressing exogenous drs gene showed significantly decreased efficiency of transformation by v- src irrespective of functional expression of v-Src kinase, while the growth rate and G 1 /S progression of the cells were not suppressed by expression of exogenous drs gene, indicating that drs has the ability to suppress v- src transformation without disturbing cell proliferation.