p38 MAP kinase mediates stress-induced internalization of EGFR: implications for cancer chemotherapy.
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Zwang Y, Yarden Y
p38 MAP kinase mediates stress-induced internalization of EGFR: implications for cancer chemotherapy.
EMBO J. 2006 Sep 20;25(18):4195-206. Epub 2006 Aug 24.
- PubMed ID
- 16932740 [ View in PubMed]
- Abstract
The epidermal growth factor receptor (EGFR) frequently associates with cancer and already serves as a target for therapy. We report that inflammatory cytokines and ultraviolet (UV) irradiation respectively induce transient or sustained phosphorylation of EGFR. Subsequently, EGFR internalizes via a Clathrin-mediated process. In cytokine-stimulated cells, EGFR recycles back to the cell surface, whereas in irradiated cells it arrests in Rab5-containing endosomes. Under both conditions, receptor internalization is instigated by the p38 stress-induced kinase. The underlying mechanism entails phosphorylation of EGFR at a short segment (amino acids 1002-1022) containing multiple serines and threonines, as well as phosphorylation of two Rab5 effectors, EEA1 and GDI. Like UV irradiation, a chemotherapeutic agent activates p38 and accelerates receptor internalization. We demonstrate that abrogating EGFR internalization reduces the efficacy of chemotherapy-induced cell death. Hence, by preventing EGFR-mediated survival signaling, the internalization route we uncovered enhances the cytotoxic effect of drugs like cis-platinum, which may underlie interactions between chemotherapy and EGFR-targeting drugs.