Objective Tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be...Objective Tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be fundamental to resolving this problem. Methods Nuclear and cytoplasmic protein extraction and immunofluorescence （IF） assay were used to detect changes in heterogeneous nuclear ribonucleoprotein K （hnRNPK） localization in H1299 cells. The evaluation of cell apoptosis in cells transfected with GFP-hnRNPK, GFP-hnRNPK S284/353A, or GFP-hnRNPK S284/353D mutant was performed using cleaved caspase-3 antibody. The gene expression of XIAP was tested by quantitative RT-PCR. Results Previously, we reported that hnRNPK antagonized TRAIL-induced apoptosis through inhibition of PKC-mediated GSK313 phosphorylation. In this study, we further demonstrate that TRAIL treatment induces cytoplasmic accumulation of hnRNPK in H1299 cells. The hnRNPK localized in the cytoplasm has a higher capacity to antagonize TRAIL-induced apoptosis. Both ERK1/2 signaling inhibitor U0126 and ERK-phosphoacceptor-site mutant （GFP-hnRNPK S284/353A） diminish cytoplasmic accumulation of hnRNPK induced by TRAIL. Moreover, we show that XlAP is involved in hnRNPK-mediated TRAIL resistance in H2299 cells. Conclusion Taken together, these results give new insights into the understanding of the molecular mechanism associated with TRAIL resistance in lung adenocarcinoma.展开更多
基金supported by National Program on Key Basic Research Project(973 Program)(Grant No.2011CB910700)Natural Science Foundation of Guangdong Province(2016A030313083,2016A030313420)+2 种基金Guangzhou Science and Technology Project(20160701175)Fundamental Research Funds for the Central Universities(Grant No.21615407,21609317)Science and Technology Program of Huadu District of Guangzhou,Guangdong Province(15-HDWS-016)
文摘Objective Tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be fundamental to resolving this problem. Methods Nuclear and cytoplasmic protein extraction and immunofluorescence （IF） assay were used to detect changes in heterogeneous nuclear ribonucleoprotein K （hnRNPK） localization in H1299 cells. The evaluation of cell apoptosis in cells transfected with GFP-hnRNPK, GFP-hnRNPK S284/353A, or GFP-hnRNPK S284/353D mutant was performed using cleaved caspase-3 antibody. The gene expression of XIAP was tested by quantitative RT-PCR. Results Previously, we reported that hnRNPK antagonized TRAIL-induced apoptosis through inhibition of PKC-mediated GSK313 phosphorylation. In this study, we further demonstrate that TRAIL treatment induces cytoplasmic accumulation of hnRNPK in H1299 cells. The hnRNPK localized in the cytoplasm has a higher capacity to antagonize TRAIL-induced apoptosis. Both ERK1/2 signaling inhibitor U0126 and ERK-phosphoacceptor-site mutant （GFP-hnRNPK S284/353A） diminish cytoplasmic accumulation of hnRNPK induced by TRAIL. Moreover, we show that XlAP is involved in hnRNPK-mediated TRAIL resistance in H2299 cells. Conclusion Taken together, these results give new insights into the understanding of the molecular mechanism associated with TRAIL resistance in lung adenocarcinoma.
