DDX3X Induces Primary EGFR-TKI Resistance Based on Intratumor Heterogeneity in Lung Cancer Cells Harboring EGFR-Activating Mutations

• Material Type: 博士論文
• Title: DDX3X Induces Primary EGFR-TKI Resistance Based on Intratumor Heterogeneity in Lung Cancer Cells Harboring EGFR-Activating Mutations
• Author/Editor: Nozaki, Koichiro
• Publication, Distribution, etc.: 新潟大学
• Publication Date: 2015-03-23
• Publication Date (W3CDTF): 2015-03-23
• Alternative Title: DDX3X Induces Primary EGFR-TKI Resistance Based on Intratumor Heterogeneity in Lung Cancer Cells Harboring EGFR-Activating Mutations; DDX3XはEGFR遺伝子変異陽性肺癌細胞において、腫瘍内不均一性に基づくEGFR-TKI一次耐性を誘発する
• Degree grantor/type: 新潟大学
• Date Granted: 2015-03-23
• Date Granted (W3CDTF): 2015-03-23
• Dissertation Number: 甲第3991号
• Degree Type: 博士（医学）
• Conferring No. (Dissertation): 甲第3991号
• Text Language Code: eng
• Note (General): The specific mechanisms how lung cancer cells harboring epidermal growth factor receptor (EGFR) activating mutations can survive treatment with EGFR-tyrosine kinase inhibitors (TKIs) until they eventually acquire treatment-resistance genetic mutations are unclear. The phenotypic diversity of cancer cells caused by genetic or epigenetic alterations (intratumor heterogeneity) confers treatment failure and may foster tumor evolution through Darwinian selection. Recently, we found DDX3X as the protein that was preferentially expressed in murine melanoma with cancer stem cell (CSC)-like phenotypes by proteome analysis. In this study, we transfected PC9, human lung cancer cells harboring EGFR exon19 deletion, with cDNA encoding DDX3X and found that DDX3X, an ATP-dependent RNA helicase, induced CSC-like phenotypes and the epithelialmesenchymal transition (EMT) accompanied with loss of sensitivity to EGFR-TKI. DDX3X expression was associated with upregulation of Sox2 and increase of cancer cells exhibiting CSC-like phenotypes, such as anchorage-independent proliferation, strong expression of CD44, and aldehyde dehydrogenase (ALDH). The EMT with switching from E-cadherin to N-cadherin was also facilitated by DDX3X. Either ligand-independent or ligand-induced EGFR phosphorylation was inhibited in lung cancer cells that strongly expressed DDX3X. Lack of EGFR signal addiction resulted in resistance to EGFR-TKI. Moreover, we found a small nonadherent subpopulation that strongly expressed DDX3X accompanied by the same stem cell-like properties and the EMT in parental PC9 cells. The unique subpopulation lacked EGFR signaling and was highly resistant to EGFR-TKI. In conclusion, our data indicate that DDX3X may play a critical role for inducing phenotypic diversity, and that treatment targeting DDX3X may overcome primary resistance to EGFR-TKI resulting from intratumor heterogeneity.; 学位の種類: 博士（医学）. 報告番号: 甲第3991号. 学位記番号: 新大院博（医）甲第637号. 学位授与年月日: 平成27年3月23日; PLoS ONE. 2014, 9(10), e111019.; 新大院博（医）甲第637号; 元資料の権利情報 : Copyright (C) 2014 Nozaki et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
• DOI: info:doi/10.1371/journal.pone.0111019; https://doi.org/info:doi/10.1371/journal.pone.0111019
• Persistent ID (NDL): info:ndljp/pid/9425148; https://dl.ndl.go.jp/pid/9425148
• Collection: 障害者向け資料
• Collection (Materials For Handicapped People:1): テキストデータ
• Collection (particular): 国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文; https://dl.ndl.go.jp/collections/A00014
• Acquisition Basis: 博士論文（自動収集）
• Date Accepted (W3CDTF): 2015-07-01T13:17:09+09:00
• Date Created (W3CDTF): 2019-08-05
• Format (IMT): application/pdf
• Access Restrictions: 国立国会図書館内限定公開
• Service for the Digitized Contents Transmission Service: 図書館・個人送信対象外
• Availability of remote photoduplication service: 可
• Periodical Title (URI): http://hdl.handle.net/10191/32275
• Data Provider (Database): 国立国会図書館 : 国立国会図書館デジタルコレクション; https://dl.ndl.go.jp