Figure 2.

Radiation-induced activation of EGFR in EGFR-antisense cells is blocked by expression of antisense EGFR mRNA. EGFR-antisense cells were cultured and were treated with doxycycline or neutralizing antibody or infected with adenovirus as described in MATERIALS AND METHODS. Cells were irradiated (2 Gy), and the tyrosine phosphorylation of the EGFR was determined over 0–300 min as in MATERIALS AND METHODS. Cells were lysed, and portions (∼100 μg) from each plate were used to immunoprecipitate EGFR, followed by SDS-PAGE and immunoblotting versus either EGFR or phosphotyrosine (active) EGFR (EGFR-phosphotyrosine); a representative experiment is shown; n = 4. Exposure time, 30 s.