中草藥對神經膠瘤細胞分化誘導之研究
Studies on the differentiation inducers of glioma cells from Chinese herbal medicine
中文摘要
神經膠腫瘤是腦瘤中惡性度和致死率最高。根據神經膠腫瘤是由神經膠細胞的前 驅性細胞產生病變而來的理論，因此有學者提出誘導神經膠腫瘤分化的觀念，希 望誘導腫瘤細胞分化為星狀細胞或寡突細胞進而降低腫瘤的惡性度，除了具有治 療效果之外，對於其他正常細胞的影響也較小。 依據中醫理論，氣滯血瘀是腫 瘤的產生的原因，我們以大鼠的神經膠腫瘤細胞為分化誘導的模型，來探討活血 化瘀中草藥是否具有分化誘導的活性。首先以臨床上有在使用於分化誘導的 sodium butyrate，在 4 mM 濃度下作為活性指標，並利用細胞形態與生長速率的 抑制進行約 50 種的活血化瘀藥的篩選。在約 50 種活血化瘀中草藥中，我們發現 如桑寄生，蠶砂，魚腥草和地蜈蚣等都具有誘導腫瘤細胞形態改變，生長速率被 抑制的作用。實驗室之前已經證明活血化瘀藥中的五靈脂及其純化物，具有誘導 大鼠的神經膠腫瘤分化成星狀細胞，因此也將其及衍生物合併觀察。 初步篩選 的結果發現，大部份的活血化瘀藥都具影響 C6 神經膠腫瘤細胞形態改變及生長 速率抑制的特性。而在五靈脂純化物和衍生物等活性物質也都具有相同的表現，
尤其是 CIL-410t。 之後進行免疫細胞化學分析和 pGFP-GS-C6 細胞的實驗，進 一步觀察瘤細胞的分化走向。實驗結果顯示 CIL-410t 會誘導 C6 和 GL261 分化 成星狀細胞，並大量表現星狀細胞特異性標記 GFAP 蛋白。 在裸鼠皮下植入腫 瘤的實驗證明，當投與 CIL-410t 可以明顯的抑制腫瘤的增殖能力，且藥物的濃 度越高抑制效果越明顯。其次以顱內種植 GL261 神經膠腫瘤細胞於小鼠
（C57/BL6）顱內投與 CIL-410t 藥物後，觀察小鼠存活率亦有輕微增加的傾向。
由我們的研究進一步證實，活血化瘀中草藥是具有誘導腫瘤細胞分化的作用，期 望將來可運用在臨床上神經膠腫瘤疾病的治療。
英文摘要
Glioma is the most life threaten brain tumor. The glioma was pathologically
degenerated from precursor glia cell. Some researcher proposed the ideal of induction glioma cell differentiation to astrocyte or oligodentrocyte such that decrease the degree of malignancy. Such differentiation inducing agents should be efficient therapeutic drugs with minor side effect on normal cells. My thesis work was aimed to explore potent glioma differentiation inducing agents in Chinese herbal medicine.
In traditional Chinese medicine theory, the reason of tumor formation was due to circulation blockage of blood and body energy. Base on this theory, the putative efficient therapeutic Chinese herbal drugs for cancer therapy were those with
“blood-activating and stasis-eliminating” actions. By using the C6 glioma as a target cell, we use 4mM sodium butyrate acting as positive control of cell
differentiation-inducing and growth arresting agents to screen bioactive
“blood-activating and stasis-eliminating” Chinese herbal drugs. In about fifty kinds of selected hearbal medicine, we have found Sangjisheng, Cansha, Yusingcao and Dewugong, showed potent differentiation inducing activity. Previous research results in our lab indicated that the crude extract of Goreishi (the faces of Trogopterus xanthipes Milne-Edwards) and its active ingredients can induce C6 glioma cell differentiation. In this thesis work, we further demonstrated the active ingredients and its synthetic analogies also have similar activities, especially CIL-410t. Experimental data of cell culture and immunocytochemistry suggest that CIL-410t can induce C6 and GL261 glioma cell differentiate to astrocyte. And in treatment of CIL-410t to nude mice with subcutaneously implanted C6 glioma cell, the tumor growth rate was attenuated in dose-response manner. Similar results can be observed in GL261
intracranially implanted C57/BL6 mice, CIL-410t treatment showed slightly increased the survival rate. Our data indicated that the blood-activating and stasis-eliminating Chinese hearbs can induce glioma cell differentiation, attenuate cell proliferation and increase survival rate of tumor cell implanted mice. We expect these results can contribute to future clinical glioma therapy.
