1. Inhibition of eEF-2 kinase sensitizes human nasopharyngeal carcinoma cells to lapatinib-induced apoptosis through the Src and Erk pathways
- Author
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Pei Yu Huang, Peijian Peng, Lin Liu, Con Tang, Zhong Lin, Zhi-Hui Wang, and Nan Chen
- Subjects
0301 basic medicine ,Elongation Factor 2 Kinase ,Cancer Research ,Nasopharyngeal neoplasm ,Apoptosis ,Lapatinib ,03 medical and health sciences ,0302 clinical medicine ,Annexin ,Cell Line, Tumor ,Genetics ,Medicine ,Humans ,Gene Silencing ,Extracellular Signal-Regulated MAP Kinases ,Protein Kinase Inhibitors ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Nasopharyngeal Carcinoma ,Cell growth ,Kinase ,business.industry ,Carcinoma ,Src/Erk signalling pathway ,Drug Synergism ,Nasopharyngeal Neoplasms ,030104 developmental biology ,src-Family Kinases ,Oncology ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Cancer research ,Synergistic effect ,Quinazolines ,RNA Interference ,Signal transduction ,business ,eEF-2 kinase ,Proto-oncogene tyrosine-protein kinase Src ,medicine.drug ,Research Article ,Signal Transduction - Abstract
Background Previous studies have reported that eEF-2 kinase is associated with tumour cell sensitivity to certain therapies. In the present study, we investigated the relationship between eEF-2 kinase and lapatinib, a dual inhibitor of EGFR and HER-2, in nasopharyngeal carcinoma (NPC) cells. Methods The effect of treatment on the growth and proliferation of NPC cells was measured by three methods: cell counting, crystal violet staining and colony counting. Apoptosis was evaluated by flow cytometry to determine Annexin V-APC/7-AAD and cleaved PARP levels, and the results were further confirmed by Western blot analysis. The expression of eEF-2 kinase and the impacts of different treatments on different signalling pathways were analysed by Western blot analysis. Results The expression of eEF-2 kinase was significantly associated with NPC cell sensitivity to lapatinib. Therefore, suppression of this kinase could increase the cytocidal effect of lapatinib, as well as reduce cell viability and colony formation. Furthermore, inhibition of eEF-2 kinase, by either RNA interference (eEF-2 kinase siRNA or shRNA) or pharmacological inhibition (NH125), enhanced lapatinib-induced apoptosis of NPC cells. The results also showed that lapatinib combined with NH125 had a synergistic effect in NPC cells. In addition, mechanistic analyses revealed that downregulation of the ERK1/2 and Src pathways, but not the AKT pathway, was involved in this sensitizing effect. Conclusions The results of this study suggest that targeting eEF-2 kinase may improve the efficacy of therapeutic interventions such as lapatinib in NPC cells.
- Published
- 2016