Figure 4.

Phospho-aspirin-2 inhibits EGFR downstream signaling. A. PA-2 1.5 × IC₅₀ inhibited STAT3 phosphorylation in MDA-MB-231 and BT-20 cells in a time-dependent manner. B: PA-2 treatment resulted in the sequential inactivation of PI3K signaling cascade, as indicated by the time-dependent reduction of the expression of p-PI3K, p-Akt, p-mTOR, p-p70S6K and p-4E-BP-1 in MDA-MB-231 and BT-20 cells. C: PA-2 reduced p-Akt expression in subcutaneous (treatment protocol) and orthotopic (prevention protocol) MDA-MB-231 xenografts. In all panels, immunoblots were performed with β-actin as loading control.