探討butylidenephthalide抑制口腔癌幹細胞化及致癌性之分子機制

口腔癌是全台死亡率排名第五的惡性腫瘤，其中口腔上皮鱗狀細胞癌(oral squamous cell carcinoma，OSCC)佔所有口腔癌的90%。根據國民健康署的統計，其五年存活率為56%。近年來廣泛的研究指出癌症幹細胞 (cancer stem cells，CSCs) 與腫瘤復發以及遠端轉移有密切關係，所以針對癌症幹細胞標靶治療也許會有突破性的發展，我們利用aldehyde dehydrogenase 1 (ALDH1)以及CD44分離出口腔癌幹細胞來進行實驗。由中草藥萃取出的天然化合物的研究逐漸蓬勃，並且發現具有抗癌的效果。本篇的研究是當歸 (Angelica sinensis)的萃取物，butylidenephthalide (BP)。發現BP能在較低濃度時抑制口腔癌幹細胞活性且不會影響正常口腔上皮細胞生長，其能降低ALDH1活性以及CD44的表現量，並且抑制口腔癌幹細胞的爬行、侵襲及群落的生成。在活體實驗中，進行BP治療的裸鼠其腫瘤也較小。進一步研究Sox2和Snail 的表現，發現Snail的表現量在經過BP處理後顯著下降，而Sox2則是微幅下降。我們進一步將Snail過度表達之後，發現癌症幹細胞的自我更新能力、爬行及侵襲能力皆增強。而加入BP之後顯著減少。證明BP可透過Snail抑制活體外及活體內口腔癌幹細胞化及致癌性。

Oral cancer is one of the common cancers worldwide, especially in South Central Asia. The mortality rate of oral cancer ranks fifth among the malignant tumors in Taiwan, with 90 % being oral squamous cell carcinoma (OSCC). According to the Health Promotion Administration, Ministry of Health and Welfare (MOHW) in Taiwan, the five-year survival rate of OSCC is 56%. In recent years, extensive research has revealed close affinity between cancer stem cells (CSCs) and tumor recurrence or metastasis. Therefore, this study aims treatment through oral cancer stem cells by isolating them via identification of aldehyde dehydrogenase 1 (ALDH1) and CD44 in OSCC. Additionally, many researches involving natural compounds extracted from Chinese herbal medicine have proved to be anti-neoplastic. Our study experiments with butylidenephthalide (BP) extracted from Angelica sinensis. We discovered that low concentration BP can not only (1) inhibit the activity of oral CSCs without affecting the regular oral epithelial cells, but also (2) suppress the migration, invasion, and colony formation of oral CSCs cancer stem cells, while (3) downregulating ALDH1 and CD44. Moreover, in vivo studies have also shown smaller tumor size of BP treated nude mice. Researching further into the expression of Sox2 and Snail, BP treatment repressed their mRNA and protein levels expression in oral CSCs. We proceeded to over-express Snail in non-oral CSCs, and resulted in enhanced self-renewal, migration, and invasion abilities of the CSCs. On the other hand, the abilities significantly reduced after the addition of BP, proving the fact that BP inhibits in vitro and in vivo oral CSCs and oncogenicity through via Snail regulation.