EGR1 downregulates the expression of 47S rRNA in association with ARF.

<p>(A) The synthesis of 47S rRNA in NIH 3T3 (ARF−/−) cells grown in 0.2% FBS (right graph) is not affected when the expression of endogenous EGR1 is silenced with 10 nM of specific siRNA (left graph). (B) Viceversa, the synthesis of 47S rRNA (left graph) is greatly reduced when both EGR1 (middle graph) and p19ARF genes (right graph) are transfected and expressed in NIH 3T3 following transfection with plasmid expression vectors. Transfection with pEGFP is shown as control. Comparison tests were assessed by one way ANOVA, and significant differences are highlighted with asterisks (* p<0.05; ** p<0.01).