IRS adaptor protein isoforms define tumor cell biology and regulate global gene expression profiles.
(A) Monolayer growth and motility of T47D-YA (YA), T47D-YA-IRS-1 (#10 and #20) and T47D-YA-IRS-2 (#1 and #6) were measured by MTT assay and (B) scratch-wound healing assay in response to IGF-I treatment. The graphs are presented as fold-change response vs. non-treated control and error bars represent standard deviation. (C) IGF-induced gene expression is IRS-dependent. cDNA microarray analysis was performed on IRS-null YA, IRS-1, and IRS-2 clones. The graph represents IGF-regulated probes in comparison to untreated samples that met both fold (1.5) and p-value (0.05) cutoff values. Hierarchical clustering was carried out on log2-transformed using Gene Cluster 3.0 and visualized in Java TreeView.