蓮蓬萃取物合併化療藥物cisplatin應用於頭頸部癌治療之研究

頭頸部癌(Head and neck cancer)的治療方式主要為放射線治療、手術及化療。順鉑(cisplatin)是常用於頭頸部癌的化療藥物，已知臨床cisplatin使用上具不良的副作用及抗藥性，為了解決當前頭頸部癌治療的盲點，目前正積極研究在治療上添加天然中草藥或食品作為輔助用藥。蓮蓬(lotus seedpod)為傳統中草藥並富含多酚類(polyphenol)成分。過去研究顯示蓮蓬具有抗氧化、抗老化及抗癌之活性，但對於合併化療藥物治療頭頸部癌仍是未知。因此本研究利用體外及體內實驗來探討蓮蓬萃取物(lotus seedpod extracts, LSE)合併cisplatin對於頭頸部癌FaDu細胞的治療效果。細胞實驗結果發現，LSE合併cisplatin處理FaDu細胞具有效抑制其生長之作用。經流式細胞儀與DAPI螢光染色分析發現，LSE合併cisplatin可增加FaDu細胞凋亡(apoptosis)反應。再以流式細胞儀及AVO螢光染色分析證實LSE合併cisplatin則有抑制細胞自噬(autophagy)的情形。進一步以西方墨點法分析顯示，LSE合併cisplatin處理能夠促進凋亡蛋白caspase 3和Bax表現量，以及抑制抗凋亡蛋白Bcl-2和p-Bad之表現；而細胞自噬蛋白LC3-II與Atg 5/12表現量也有下降的趨勢。在腫瘤移植裸鼠試驗中，以cisplatin合併LSE處理的腫瘤有顯著縮小。另外，加入細胞自噬抑制劑3-MA會降低LSE合併cisplatin處理下之細胞自噬作用，同時更增加細胞凋亡程度。總結，LSE可以增加頭頸部癌以cisplatin化療的效果，達到有效抑制腫瘤生長作用。

The main types of treatment for managing head and neck cancer are radiotherapy, surgery, and chemotherapy. Cisplatin, is a well-known chemotherapeutic drug, has been used for treatment of numerous human cancers including head and neck cancer. However, because of drug resistance and numerous undesirable side effects, combination therapies of cisplatin with traditional Chinese medicine could improve the efficiency of tumor inhibition, while mitigating their side effects. Lotus seedpod, used as a traditional Chinese herbal medicine, has been shown to possess antioxidant, anti-aging, and anticancer activities. In this study, we examined the efficacy-enhancing effect of lotus seedpod extracts (LSE), which is rich in polyphenol, and cisplatin combined treatment on human head and neck squamous cell carcinoma FaDu cells. In vitro, a treatment of LSE combined with cisplatin had a synergistic inhibitory effect on cell proliferation. LSE potentiated the cytotoxic effect of cisplatin in FaDu cells through apoptosis, as shown by flow cytometric analysis and DAPI staining. In addition, cisplatin-induced formation of acidic vesicular organelles (AVO) and the upregulation of microtubule associated protein 1 light chain 3-II (LC3-II) and Atg5/12, markers of autophagy, were decreased by LSE. Western blotting showed the addition of LSE to cisplatin induced synergistic apoptosis, which could be corroborated to the changes in an increase in protein levels of Bax, and the decreases in Bcl-2 and p-Bad in these cells, resulting in activation of caspase-3. In addition, 3-MA reduced the autophagy of LSE with cisplatin and increased apoptosis on this combined treatment. Finally, the combination therapy of LSE with cisplatin was evidenced by its synergistic inhibition on the growth of FaDu cells in xenograft tumor studies. The results indicate that LSE, in combination with chemotherapeutics, is likely to represent a potential therapeutic strategy for head and neck cancer.