Figure 2

Id1 and Id2 mRNA and protein expression in SGC cells in the presence or absence of serum. (A) Total RNA isolated from ACC2 and ACCM cells cultured in 10% FBS or in serum-free medium (0%) were analyzed for expression of Id1 and Id2 by Northern blotting. To control for RNA quantity and integrity, the ethidium bromide-stained gel is shown in the lower panel. (B) Western blot comparing the levels of Id1 and Id2 protein expression in cells cultured under the same conditions as in (A) is shown. (C) Relative expression of Id1 in ACC2 and ACCM cells is indicated by the expression of luciferase (a reporter driven by a human Id1 promoter). * indicates a significant difference between the two cell lines (p < 0.05, Student’s t test).