Curcumin potentially modulates EGFR expression by accelerating protein degradation in gefitinib-resistant NSCLC cell lines.

<p>(A) Analysis the half-life of EGFR protein level in 100 µg/ml cycloheximide treated CL1-5 cells with or without 10 µM curcumin by Western blotting. (B) Western blotting analysis revealed that MG132 recover the EGFR level of the curcumin-affected EGFR protein depletion. β-actin used as the internal control and the numbers below the row of the EGFR indicate the densitometric values normalized with the relative β-actin value. (C) Detection of ubiquitin (Ub) levels by immunoprecipitation of EGFR in CL1-5, A549 and H1975 cells showed the elevation of poly-Ub expressions in the presence of curcumin (10–15 µM). Ub and EGFR levels were measured by Western blotting.