2024-03-28T12:24:20Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1237962016-02-18T03:26:32Zcom_10261_134com_10261_1col_10261_513
Control of FLIP(L) expression and TRAIL resistance by the extracellular signal-regulated kinase1/2 pathway in breast epithelial cells
Yerbes, Rosario
López-Rivas, Abelardo
Reginato, Mauricio J.
Palacios, Carmen
Póster presentado en 8th European Workshops on Cell Death: Death à la carte, celebrado en Monêtier-les-Bains, Serre Chevalier Valley (France), del 3 al 8 de junio de 2012
Increased activation of the epidermal growth factor receptor (EGFR) is frequently observed in tumors, and inhibition of the signaling pathways originated in the EGFR normally renders tumor cells more sensitive to apoptotic stimuli. However, we show that inhibition of EGFR signaling in non-transformed breast epithelial cells by EGF deprivation or gefitinib, an inhibitor of EGFR tyrosine kinase, causes the upregulation of the long isoform of caspase-8 inhibitor FLICE-inhibitory protein (FLIP(L)) and makes these cells more resistant to the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We demonstrate that the extracellular signal-regulated kinase (ERK)1/2 pathway plays a pivotal role in the regulation of FLIP(L) levels and sensitivity to TRAIL-induced apoptosis by EGF. Upregulation of FLIP(L) upon EGF deprivation correlates with a decrease in c-Myc levels and c-Myc knockdown by siRNA induces FLIP(L) expression. FLIP(L) upregulation and resistance to TRAIL in EGF-deprived cells are reversed following activation of an estrogen activatable form of c-Myc (c-Myc-ER). Finally, constitutive activation of the ERK1/2 pathway in HER2/ERBB2-transformed cells prevents EGF deprivation-induced FLIP(L) upregulation and TRAIL resistance. Collectively, our results suggest that a regulated ERK1/2 pathway is crucial to control FLIP(L) levels and sensitivity to TRAIL in non-transformed cells, and this mechanism may explain the increased sensitivity of tumor cells to TRAIL, in which the ERK1/2 pathway is frequently deregulated.
2015-10-26T07:46:40Z
2015-10-26T07:46:40Z
2012-06-03
2015-10-26T07:46:40Z
póster de congreso
8th European Workshops on Cell Death (2012)
http://hdl.handle.net/10261/123796
eng
Sí
closedAccess