Fig. 1

In vitro dasatinib (Das) treatment alters EGFR compartmentalization. MDA-MB-231 (left) and MDA-MB-468 (right) cells were treated with dasatinib IC₅₀ values for 48 h (+) or left untreated (−). A representative western blot shows expression of pEGFR (Tyr845), EGFR, pSrc (Tyr416), and Src (band identified by an arrow) (a). A plot of densitometry values of untreated and treated cell lysates (b). Densitometry values were obtained as the ratio of protein to GAPDH. Nuclear (N) and membrane plus cytoplasmic (C) extracts were collected from MDA-MB-231 (c) and MDA-MB-468 (d) cells after 48 h with and without treatment and evaluated for EGFR and Src expression and activity. Protein derived from nuclear compartment was normalized against H3 loading control while protein from the cytoplasm was normalized against GAPDH. High membrane-bound [⁸⁹Zr]Zr-cetuximab was displayed in treated versus untreated cells incubated at 4 °C to stop temperature-dependent internalization (e). Higher internalized [⁸⁹Zr]Zr-cetuximab is displayed at 37 °C in the treated groups (f)