FIG 2.

The IRS2 C-terminal tail regulates tumor cell invasion. (A) Schematic of WT and mutant IRS proteins. (B) PyMT:Irs1/2^−/− cells were stimulated with IGF-1 (50 ng/ml) for 10 min, and cell extracts were immunoprecipitated (IP) with an HA-specific antibody and immunoblotted with antibodies specific for HA or the p85 subunit of PI3K (p85). Whole-cell extracts (WCE) were also immunoblotted with antibodies specific for HA, pAkt (S473), pAkt (T308), Akt, and tubulin. (C and D) PyMT:Irs1/2^−/− cells expressing IRS proteins were assayed for invasion. (C) Matrigel Transwell invasion assays. The data shown represent the means and SEM of the results of three independent experiments. (D) Matrigel-collagen I 3D invasion assays. The data shown represent the means and SEM of the results of a representative experiment performed three times independently. Representative images of colonies are shown below (magnification, ×10). (E) SUM-159:IRS1/2^−/− cells expressing IRS proteins were assayed for invasion in a Matrigel Transwell invasion assay. The data shown represent the means and SEM of the results of four independent experiments. *, P < 0.05 relative to EV; **, P < 0.01 relative to EV; ##, P < 0.01 relative to IRS2. Molecular weight markers (in kilodaltons) are indicated to the left of the immunoblot.