2011-05-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/686152摘要：Sorafenib是第一個也是目前唯一獲得核准用於晚期肝細胞癌治療的標靶藥物。在我們過去的研究中發現，GADD45β (過去知道它與細胞壓力和細胞淍亡有關)可能是sorafenib治療的作用標靶之一。它會受到sorafenib刺激而會有明顯的上升，且此一作用與sorafenib 對於Raf/MEK/ERK 訊息傳遞路徑的抑制能力無關，更重要是肝癌細胞內GADD45β之表現及其治療後的反應，可能可以做為肝癌病患接受sorafenib 治療的療效預測指標。此外我們過去的研究也發現sorafenib是透過活化JNK使GADD45β上升，若抑制JNK活化則會破壞sorafenib誘導GADD45β上升。因此我們假設：調控GADD45β與JNK訊息傳遞路徑，可以改善sorafenib治療效果，與作為未來新藥研發的可能標的。我們已經根據相關研究發展可誘發GADD45β表現之先導化合物，初步結果顯示即使對sorafenib有抗藥性的肝癌細胞也有療效。本計畫中，我們將探討為何sorafenib可以有效治療肝細胞癌，主要針對GADD45家族蛋白，JNK與細胞壓力相關的蛋白，在此過程所扮演的角色進行探討，並且據此研發新的抗癌藥物。過去研究顯示GADD45與JNK訊息傳遞路徑在不同的細胞狀態﹝包括細胞種類、所受壓力的種類、以及不同微環境﹞，對細胞存活可能會產生相反的作用﹝促進存活或是促進細胞凋亡﹞。因此本研究除了用傳統的分子生物學方式研究相關作用機轉外，也將利用一個整合磷酸化蛋白質體技術以及全基因組核醣核酸干擾篩選技術建立基因交互作用圖譜的方式，全面性地探討sorafenib抗藥性的作用機轉並尋找新的藥物研發標的。我們特定目標包括：(1) 澄清GADD45 家族蛋白(包括GADD45α, β, and γ)與JNK傳遞路徑對於各項細胞功能之影響與調控機轉及可能的作用; (2) 探討GADD45蛋白，c-Jun及相關蛋白質表現對於預測sorafenib藥物對肝癌治療效果的價值; (3) 根據對我們已知先導化合物的結構-活性分析及最適化研究，發展出可以透過調控GADD45訊息傳遞活性，克服sorafenib以及其他標靶藥物抗藥性的藥物。每年全世界有超過70萬人死於肝癌，因此任何治療上的進步都有巨大的潛在市場價值。透過本計畫希望能有兩個方向來改善肝癌病患的治療效果: (1) 對病人幫助:確認適當的sorafenib預測性生物指標，希望將來可以有效幫助病人了解是否適用sorafenib治療，達到個人化醫療目的與避免醫療資源的浪費; (2) 新藥研發方面: 全面性分析sorafenib抗藥性機轉，找到最重要的訊息傳遞路徑將有效研發出更有效的抗癌藥物。<br> Abstract: Sorafenib is the first approved molecular targeted therapy for the treatment of advanced hepatocellular carcinoma (HCC). In search of potential therapeutic targets of sorafenib, we have found that GADD45, which is associated with cellular stress response and apoptosis regulation, was induced in HCC cells after sorafenib treatment. GADD45 induction is independent of MEK/ERK signaling, the presumed target of sorafenib, and may help predict sorafenib sensitivity in HCC cells. These findings support the role of GADD45β as a predictive biomarker of sorafenib efficacy in HCC. In addition, we also found that JNK signaling induction is critical in the induction of GADD45and inhibition of JNK activity antagonized sorafenib-induced GADD45β expression and apoptosis. Therefore, we hypothesize that modulation of GADD45β and JNK signaling pathways may reverse sorafenib resistance and serve as new therapeutic targets in HCC.In the present project we will focus on the roles of GADD45 family proteins, JNK signaling, and cellular stress mechanisms in mediating the anti-tumor effects of sorafenib in HCC. GADD45 and JNK signaling pathways may have opposite effects on cell survival (pro-survival or pro-apoptotic), depending on the cellular context (cell types, types of stress, microenvironment). Therefore, in addition to conventional molecular biology approach, a comprehensive approach of phospho-proteomic analysis and genetic interaction profiling will be used to help dissect the complex interaction among key signaling pathways in HCC cells that govern drug resistance.Our specific aims are (1) to clarify the functional significance, regulatory mechanisms, and potential interactions of GADD45 family proteins (including GADD45α, β, and γ) and JNK signaling in HCC cells; (2) to explore GADD45 proteins, c-Jun and related proteins levels as predictive biomarkers of sorafenib treatment in HCC patients; and (3) to develop novel compounds, based on the structure-activity-relationship analysis of our lead compounds, that may overcome the resistance of HCC cells to sorafenib and other molecular targeted therapy by regulating the GADD45 signaling.With a worldwide HCC-related death of nearly 700,000 per year, any improvement in drug treatment for HCC will represent huge health market revenues. Results of this project will improve therapy for HCC patients in the following aspects that (1) patient enrichment: establishment of biomarkers to predict therapeutic efficacy will help identify sub-populations of HCC patients who will benefit most from sorafenib treatment, and validation of such biomarkers will help not only personalized therapy but also rational allocation of health resources; (2) new drug development: the comprehensive analysis of key signaling pathways of drug resistance will expedite identification of novel therapeutic targets and validation of candidate compounds.肝細胞癌sorafenib抗藥性基因體研究磷酸化蛋白質體研究新藥研發預測性生物指標GADD45JNKhepatocellular carcinomasorafenibdrug resistancegenomicsphospho-proteomicsnew drug developmentpredictive biomarkerGADD45JNK