1. 探討TRIP6與IFIT5在神經膠質母細胞瘤中的交互作用 / 2. 海檬果萃取物對神經膠質母細胞瘤及其癌幹細胞的影響

Abstract

I. 甲狀腺素受體作用蛋白質（tyroid receptor interacting protein 6, TRIP6）作為溶血磷脂酸（lysophosphatidic acid, LPA）受體下游的影響目標，會調節細胞肌動蛋白質（actin），進一步影響細胞移動及細胞內部多重訊號傳遞。TRIP6目前已知在多型性神經膠質母細胞瘤 （glioblastoma, GBM）有過度表現的現象，可能與GBM高度侵襲性有關。干擾素誘導四肽重複蛋白質5（interferon induced protein with tetratricopeptide repeats 5, IFIT5）為干擾誘導蛋白質家族的一員，參與人體先天性免疫反應。但有學者發現有部份獨立的IFIT5會與肌動蛋白質連結並表現在細胞膜上，可能與調控細胞移動有關。我們檢測IFIT5在多型性膠質母細胞瘤（glioblastoma, GBM）細胞中是否參與TRIP6調控的細胞遷移與腫瘤形成。本研究透過免疫共沉澱證實TIPR6與IFIT5在細胞中的確存在交互作用，並利用活細胞顯微影像追蹤兩者對細胞遷移的影響。我們發現IFIT5本身並不會增加細胞泡足的產生，但會增進TRIP6造成的細胞動態變化。

II. 多型性神經膠質母細胞瘤（Glioblastoma multiforme, GBM）是成人原發性腦癌中最常見的惡性腦瘤，被世界衛生組織（WHO）歸列為第四級神經膠質瘤。其具有高度侵潤性與異質性，對傳統化療及放射療法皆有抗性，因此許多病患在術後仍有很高的機率再復發，其存活率不超過14個月。部分學者認為，癌症復發與抗藥性可能與癌細胞中少部分的癌幹細胞有關，因此針對癌幹細胞作為治療策略亦是一重要方法。現今有諸多研究嘗試從植物中萃取成分，這些成分具有抗發炎、抗病蟲害或抗癌症之功能，進而研發出更多相似結構分子作為治療疾病的藥物。本文研究發現海檬果萃取物及neriifolin會抑制細胞生長及細胞遷移，並造成細胞週期停滯與細胞凋亡的發生。我們進一步探討neriifolin對神經膠質母細胞瘤類癌幹細胞的訊息路徑，發現neriifolin主要透過抑制Akt路徑活化而使細胞生長能力降低並抑制神經膠質母細胞瘤癌幹細胞的維持。I Thyroid receptor interacting protein 6（TRIP6）is a downstream signaling molecule of lysophosphatidic acid（LPA）receptor. It enhances activation of signaling molecules regulating actin to induce cell migration, division and proliferation. TRIP6 is overexpressed in glioblastoma multiform（GBM）and may be a characteristic of aggressiveness of GBM. Interferon induced protein with tetratricopeptide repeats 5（IFIT5）is a member in interferon induced protein family, and involves in the regulation of human innate immune response. It has been reported that IFIT5 interaction with actin on the cell cortex, and may involve in the regulation of cell migration. To examine whether IFIT5 plays a role in the TRIP6 regulated cell migration and glioblastoma tumorigenesis, we investigated the interaction of these two proteins. Here, we demonstrated the interaction of IFIT5 and TRIP6 in cells by co-immunoprecipitation. Moreover, we elucidated the effect of these two proteins on cell migration by live cell imaging, and found that IFIT-5 itself does not enhance the cell blebbing, but promotes TRIP6-mediated cell dynamics.

II Glioblastoma multiforme （GBM）, classified as the grade IV astrocytoma, is the most common malignant brain cancer in adult. GBM possess the characters of invasiveness, heterogeneity and resistance to chemical and radiation therapy. The GBM patients have poor prognosis, the median survival of the patients is about 14 months. Some studies have showed that the glioblastoma stem cells（GSCs）, a small population of cells, may play the critical role in cancer relapse. Therefore, targeting GSCs is one of the potential therapeutic strategies for GBM. Recent researches studied the plant extracts and found the anti-inflammatory, anti-virus and anti-cancer activity of compositions in the plants. These components can be developed further to other structurally similar molecules for treatment of diseases. In this study, we detection that two extracts and neriifolin inhibited viability and movement of GBM cells and GSCs, and induced cell cycle arrest and apoptosis of GSCs. Stimulation of GSCs with neriifolin inhibited activity of Akt pathway to reduce cell viability and maintain of GSCs.