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Conference Paper: EGFR-mutant lung adenocarcinomas mutation profiles reveal ARID1A might be a novel tyrosine kinase resistance pathway

TitleEGFR-mutant lung adenocarcinomas mutation profiles reveal ARID1A might be a novel tyrosine kinase resistance pathway
Authors
Issue Date2018
PublisherAmerican Association for Cancer Research. The Journal's web site is located at http://cancerres.aacrjournals.org/
Citation
Proceedings of the 109th American Association for Cancer Research (AACR) Annual Meeting, Chicago, USA, 14-18 April 2018. In Cancer Research, 2018, v. 78 n. 13, Suppl. 1, Abstract no. LB-196 How to Cite?
AbstractLung cancer has the highest mortality across all cancers in the world. Epidermal growth factor receptor (EGFR) is commonly mutated in lung adenocarcinomas from Asian non-smoking females. These tumors usually respond to EGFR tyrosine kinase inhibitors (EGFR-TKI), but the outcomes vary in different patients. Though EGFR T790M, amplification of MET and other mechanisms have been shown to confer EGFR-TKI resistance, the molecular mechanisms in around 30% of patients are still unknown. To uncover novel candidate pathways of EGFR-TKI resistance, we analyzed the whole exome mutation profiles of pre-treatment, EGFR T790M-free lung adenocarcinomas with typical activating mutations (L858R, exon 19 deletions). Amongst 19 non-responding (NR) tumors without significant shrinkage after gefitinib or erlotinib treatment, 67 cancer-related genes showed coding region non-synonymous single nucleotide variations (SNV) or insertion-deletions (indels) but they were not detected in 22 responding tumors. Gene set enrichment analysis (GSEA) showed 14 of the 67 genes were involved in the EGFR and WNT signaling network (false discovery rate q=1.14 e-8 for EGFR and q=4.3 e-9 for WNT), including well-known TKI resistance-related genes PIK3CA, PTEN and NF1. Notably, ARID1A, which encodes a subunit of the chromatin remodeling complex, showed nonsense mutations in 2 NR but not responding tumors, which were validated by Sanger sequencing. More than 40% of ARID1A mutations in lung adenocarcinomas recorded in COSMIC were nonsense mutations or frameshift indels. Loss of function mutations of ARID1A have also been reported in various cancers, together suggesting ARID1A might be a tumor suppressor but its involvement in EGFR mutant lung cancers is unknown. To investigate the potential role of ARID1A, its expression was first studied using Kaplan-Meier plotter. Low expression of ARID1A is associated with significantly better overall survival than high expression level in lung adenocarcinoma patients (p=8.5 e-7). To test whether loss of ARID1A could cause TKI resistance, ARID1A was knocked down by shRNA in HCC827 lung cancer cell line harboring EGFR exon19 deletion. MTT cell viability assay using gefitinib showed increase of IC50. Western blot assay further showed ARID1A knockdown increased phosphorylation of AKT at Ser473. Together, the findings suggest loss of ARID1A could lead to EGFR bypass and promote activation of the downstream PI3K/AKT pathway, leading to EGFR TKI resistance. Overall, our findings suggest EGFR-TKI resistance mutations could be detected before TKI drug selection. Resistant gene mutations present in pre-treatment tumors could help to predict the treatment response. More specifically, our study identified a promising gene list involved in EGFR-TKI resistance, and suggested ARID1A loss could be a novel EGFR-TKI resistance mechanism.
Persistent Identifierhttp://hdl.handle.net/10722/263902
ISSN
2019 Impact Factor: 9.727
2015 SCImago Journal Rankings: 5.372

 

DC FieldValueLanguage
dc.contributor.authorGao, X-
dc.contributor.authorXu, H-
dc.contributor.authorHo, JCM-
dc.contributor.authorChan, OSH-
dc.contributor.authorXu, F-
dc.contributor.authorWang, JW-
dc.contributor.authorLee, VHF-
dc.contributor.authorTin, VPC-
dc.contributor.authorXiao, Z-
dc.contributor.authorWang, S-
dc.contributor.authorYam, JWP-
dc.contributor.authorWong, MP-
dc.date.accessioned2018-10-22T07:46:18Z-
dc.date.available2018-10-22T07:46:18Z-
dc.date.issued2018-
dc.identifier.citationProceedings of the 109th American Association for Cancer Research (AACR) Annual Meeting, Chicago, USA, 14-18 April 2018. In Cancer Research, 2018, v. 78 n. 13, Suppl. 1, Abstract no. LB-196-
dc.identifier.issn0008-5472-
dc.identifier.urihttp://hdl.handle.net/10722/263902-
dc.description.abstractLung cancer has the highest mortality across all cancers in the world. Epidermal growth factor receptor (EGFR) is commonly mutated in lung adenocarcinomas from Asian non-smoking females. These tumors usually respond to EGFR tyrosine kinase inhibitors (EGFR-TKI), but the outcomes vary in different patients. Though EGFR T790M, amplification of MET and other mechanisms have been shown to confer EGFR-TKI resistance, the molecular mechanisms in around 30% of patients are still unknown. To uncover novel candidate pathways of EGFR-TKI resistance, we analyzed the whole exome mutation profiles of pre-treatment, EGFR T790M-free lung adenocarcinomas with typical activating mutations (L858R, exon 19 deletions). Amongst 19 non-responding (NR) tumors without significant shrinkage after gefitinib or erlotinib treatment, 67 cancer-related genes showed coding region non-synonymous single nucleotide variations (SNV) or insertion-deletions (indels) but they were not detected in 22 responding tumors. Gene set enrichment analysis (GSEA) showed 14 of the 67 genes were involved in the EGFR and WNT signaling network (false discovery rate q=1.14 e-8 for EGFR and q=4.3 e-9 for WNT), including well-known TKI resistance-related genes PIK3CA, PTEN and NF1. Notably, ARID1A, which encodes a subunit of the chromatin remodeling complex, showed nonsense mutations in 2 NR but not responding tumors, which were validated by Sanger sequencing. More than 40% of ARID1A mutations in lung adenocarcinomas recorded in COSMIC were nonsense mutations or frameshift indels. Loss of function mutations of ARID1A have also been reported in various cancers, together suggesting ARID1A might be a tumor suppressor but its involvement in EGFR mutant lung cancers is unknown. To investigate the potential role of ARID1A, its expression was first studied using Kaplan-Meier plotter. Low expression of ARID1A is associated with significantly better overall survival than high expression level in lung adenocarcinoma patients (p=8.5 e-7). To test whether loss of ARID1A could cause TKI resistance, ARID1A was knocked down by shRNA in HCC827 lung cancer cell line harboring EGFR exon19 deletion. MTT cell viability assay using gefitinib showed increase of IC50. Western blot assay further showed ARID1A knockdown increased phosphorylation of AKT at Ser473. Together, the findings suggest loss of ARID1A could lead to EGFR bypass and promote activation of the downstream PI3K/AKT pathway, leading to EGFR TKI resistance. Overall, our findings suggest EGFR-TKI resistance mutations could be detected before TKI drug selection. Resistant gene mutations present in pre-treatment tumors could help to predict the treatment response. More specifically, our study identified a promising gene list involved in EGFR-TKI resistance, and suggested ARID1A loss could be a novel EGFR-TKI resistance mechanism.-
dc.languageeng-
dc.publisherAmerican Association for Cancer Research. The Journal's web site is located at http://cancerres.aacrjournals.org/-
dc.relation.ispartofCancer Research-
dc.relation.ispartof109th Annual Meeting of the American Association for Cancer Research (AACR)-
dc.titleEGFR-mutant lung adenocarcinomas mutation profiles reveal ARID1A might be a novel tyrosine kinase resistance pathway-
dc.typeConference_Paper-
dc.identifier.emailHo, JCM: jhocm@hku.hk-
dc.identifier.emailLee, VHF: vhflee@hku.hk-
dc.identifier.emailTin, VPC: pctin@hku.hk-
dc.identifier.emailXiao, Z: xiaozj@hku.hk-
dc.identifier.emailYam, JWP: judyyam@pathology.hku.hk-
dc.identifier.emailWong, MP: mwpik@hku.hk-
dc.identifier.authorityHo, JCM=rp00258-
dc.identifier.authorityLee, VHF=rp00264-
dc.identifier.authorityYam, JWP=rp00468-
dc.identifier.authorityWong, MP=rp00348-
dc.identifier.doi10.1158/1538-7445.AM2018-LB-196-
dc.identifier.hkuros294376-
dc.identifier.volume78-
dc.identifier.issue13, Suppl. 1-
dc.publisher.placeUnited States-

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