Figure 1From: Genes regulated by estrogen in breast tumor cells in vitro are similarly regulated in vivoin tumor xenografts and human breast tumorsGene expression signatures of estrogen regulation in vitro and in vivo. (a) Expression data matrix of genes showing either induction or repression by E2 in vitro (p < 0.01 at 4, 8, 12, or 24 hour time points). Each row represents a gene; each column represents a sample. The level of expression of each gene in each sample is represented using a yellow-blue color scale (yellow, high expression); gray indicates missing data. Shown alongside our in vitro time course dataset are the expression values for the corresponding genes in two independent mRNA profile datasets of E2-treated breast cells ('Rae' dataset from [5] of cell lines MCF-7, BT-474, and T47-D; 'Finlin' dataset from [11] of MCF-7). (b) Alongside the in vitro datasets are the corresponding values for MCF-7 xenografts with or without E2 supplementation (E2 withdrawn for 24 hours and 48 hours in the -E2 group). Genes in cluster 'B' (a) that show significant up-regulation by E2 in each of the four datasets are listed (an asterisk indicates positively correlated (p < 0.05) with age-correlation ERα expression (Figure 2); bold type indicates having higher expression in ERα+ compared to ERα- breast tumors (p < 0.01) according to the 'van't Veer' dataset from [15]); italics indicates having higher expression in ERα- compared to ERα+ breast tumors). (c) Genes MYB (c-myb) and MYBL1 (A-MYB) are regulated by E2 in vivo. Expression patterns for genes from (b) were validated by RT-PCR. Shown are the mean and standard deviation of individual samples assayed in triplicate. Tumor volumes (expressed in mm3) are shown above each bar.Back to article page