2016-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/647159摘要：肺癌不論是在台灣或是世界各國都屬於最嚴重的癌症死亡原因之一。由於肺癌細胞的表皮生長素受體(EGFR)受到活化後，可促進抗凋亡、細胞增生、血管新生、侵襲及轉移。因此，近年來針對 EGFR開發出一些小分子tyrosine kinase inhibitor (EGFR-TKIs)（如: gefitinib、erlotinib、afatinib、AZD9291)，這類藥物對某些肺癌病人有明顯的療效，但使用數個月後就產生抗藥性。此外，微小核醣核酸(microRNA)是體內的非蛋白質製造(non-protein coding)之微小核醣核酸，是重要之基因調節因子。最近之證據顯示，微小核醣核酸之異常表現與腫瘤形成、病患預後及化療反應有關。據此，我們利用微小核醣核酸微陣列(microRNA microarray) 分析了二組分別對EGFR-TKI呈現敏感性 (PC9與HCC827) 與抗藥性的細胞株 (PC9/gef與HCC827/gef)之間，微小核糖核酸表現量的差異程度。初步的研究發現，抗藥性細胞中的miR-146b-5p表現量遠低於敏感性細胞。如果導入miR-146b-5p進去抗藥性細胞後，也能夠造成抗藥性細胞生長速度變慢，並且造成細胞回復EGFR-TKI的感受性以及活化caspase-3, caspas-9, PARP等凋亡蛋白的表現。透過分析 miR-146b-5p下游的標的蛋白後，我們發現除了已知的TRAF6與IRAK1受到其調控外，另外我們更感興趣的則是表皮生長素受體(EGFR)的蛋白表現與mRNA也受到miR-146b-5p的調控。在此計畫中，除了探討TRAF6/IRAK1是否會影響細胞對EGFR-TKI的敏感性之外。EGFR訊息傳遞路徑是影響肺癌細胞生長存活最重要的因子，我們將更深入探討miR-146b-5p與EGFR間的關聯性以及是什麼原因造成miR-146b-5p表現量降低。最終期望能對EGFR-TKI抗藥性之病患的治療找出一條新的方向。<br> Abstract: Lung cancer is one of the leading cause of cancer death around the world. A variety of molecular studies show that up-regulation and activation of epidermal growth factor receptor (EGFR) in lung cancer lead to anti-apoptosis, cellular proliferation, and metastasis. Recently, EGFR-targeted tyrosine kinase inhibitors (EGFR-TKIs) were developed and applied to patients harboring activating-EGFR mutations. Although EGFR-TKIs are effective in patients, tumor cells develop acquired resistance to EGFR-TKIs in a few of months.MicroRNA belonging to the class of small non-protein coding RNA plays a key role in regulating cellular homeostasis as endogenous RNA interference. Emerging studies show that aberrant expression of microRNA results in tumor progression, prognosis, and poor response to chemotherapy. In preliminary study, we set up the in vitro model using two pairs of TKI-sensitive (PC9, HCC827) and TKI-resistant (PC9/gef, HCC827/gef) cell lines to screen the microRNA microarray. We show that miR-146b-5p expression was significantly suppressed in the TKI-resistant cell lines (PC9/gef, and HCC827/gef). In the meanwhile, exogenous introduction of miR-146b-5p into PC9/gef cells led to inhibiting cell proliferation, restoring sensitivity to EGFR-TKIs, and activation of pro-apoptotic caspase-3, -9, and PARP proteins.We also show that TRAF6, IRAK1, and EGFR molecules were suppressed by miR-146-5p in both RNA and protein levels.In the project, (A) we'd like to investigate the role of miR-146b-5p/IRAK1/TRAF6 in EGFR-TKI sensitivity. Importantly, (B) we'd like to investigate the correlation between miR-146b-5p and EGFR signaling pathway which plays a critical role in lung cancer. Finally, (C) we'd evaluate whether epigenetic aberrations are involved in down-regulation of miR-146b-5p. We hope that it will bring a new era to the treatment of lung cancer.肺癌表皮生長素受體抗藥性微小核醣核酸lung cancerEGFRresistancemicroRNA-146b-5p