喜樹果水煎液對於子宮內膜癌之抑癌機制探討並與喜樹鹼之機制比較

To explore the anticancer mechanism of Aqueous Extract of Campotheca Acuminata Decne on Endometrial cancer cells comparing with Camptothecin

林季嫻(Chi-Shian Lin)

指導教授 ： 吳瑞裕

臺北醫學大學/醫學院/醫學科學研究所/碩士(2014年)

摘要

癌症為台灣十大死因之首，而卵巢癌、子宮內膜癌分居女性婦癌的第二名及第三名。在台灣地區子宮內膜及卵巢癌的發生率有逐漸上升的趨勢。統計台灣每年約有5000名的婦女宣告罹患婦癌，因婦癌死亡者約1500人。因此婦癌的治療一直為重要的課題。而化學療法藥物毒性較強，除了攻擊癌細胞外，也作用於正常細胞上，往往造成病人整體免疫力低下及諸多副作用。因中藥本身為天然藥草因此安全性較高外，副作用也較低而能減緩患者治療中的不適。

喜樹為中國之特有物種，(Campotheca Acuminata Decne) 為紫樹科 (Nyssaceaea)之植物。中國民間就利用喜樹果及樹葉治療消化道腫瘤。而在1960年代，從喜樹的樹皮及枝幹中萃取出喜樹鹼 (Camptothecin，CPT)成分且發現有良好的抗腫瘤活性，其主要機制為抑制Topoisomerase I 的活性，導致DNA斷裂、細胞週期停滯，進而導致細胞死亡。而目前市面上已有兩種喜樹鹼之半合成衍生物Topotecan與Irinotecan (CPT-11)作為化療藥物，廣泛的運用於治療肺癌、卵巢癌與大腸直腸癌中。除了喜樹鹼之外，喜樹果中仍萃取出許多有效成分，而其中造成細胞毒性的機制尚未完全明瞭。

因此本研究將探討喜樹果水煎液於人類子宮內膜癌細胞中之抑癌作用和機制與喜樹鹼有和不同。首先為了解喜樹果水煎液對於人類子宮內膜癌細胞是否有細胞毒性及其機制為何，選用三株人類子宮內膜癌細胞(HEC1A、HEC1B、KLE)培養，以形態學觀察細胞是否會因為處理喜樹果水煎液而造成形態學變化。在細胞存活實驗指出，喜樹果水煎液 (AE-CA)相較於喜樹鹼 (CPT)有較佳的細胞毒殺性。接著利用PI Stain來偵測子宮內膜癌細胞週期，則結果指出細胞受喜樹果水煎液影響而造成G2/M arrest。由西方墨點法得知喜樹果水煎液會成cyclin A及cyclin B之累積，且活化caspase-3與caspase-7使細胞走向凋亡，此結果皆與已知喜樹鹼之機制類似。此外喜樹果水煎液在HEC-1A及HEC-1B細胞中與化療藥物順鉑具有協同作用，因而增強細胞毒殺性。此研究結果提出喜樹果水煎液為一種有效治療子宮內膜癌治療的替代藥物，能取代原本與順鉑搭配之化療藥物，成為一種新的替代治療方案。

關鍵字

喜樹果水煎液 ； 喜樹鹼 ； 人類子宮內膜癌

並列摘要

Cancer is the leading cause of death in Taiwan in 2013. The most common gynecologic cancers are cervical cancer, ovarian cancer and endometrial cancer. The incidence of ovarian cancer and endometrial cancer is getting higher each year. Because lacking of obvious warning symptom in early stage, in most case symptoms occur while the cancer has spread to other organs. According to the statistic, about 5000 woman were told to having Gynecologic cancer per year, causing 1500 death per year. Thus Gynecologic cancer treatment has become an important issue. The toxicity of chemotherapy drugs not strictly restricted only to cancer cells but also damage normal cells, causing side effects.
Camptotheca Acuminata Decne is an endemic species of China, belongs to the Nyssaceae family. In tradition, use its fruits and the leave as the treatment of gastric cancer. Camptothecin (CPT) was found having good anticancer activity, which is an extraction from the bark and the branch of Camptotheca Acuminate. The main mechanism of CPT is blocking the activity of topoisomerase I, resulting DNA fragment, cell cycle arrest, and cell death. CPT derivatives, Topotecan and Irinotecan are as clinical chemotherapy drug, wildly use in lung cancer, ovarian cancer, and colon cancer treatment. No only CPT, there is still other active ingredient in Camptotheca Acuminata Decne, but the molecular and cellular mechanisms of the cytotoxicity are not fully understood. In this study we examine whether Aqueous Extract of Camptotheca Acuminata Decne (AE-CA) has a different mechanism from CPT on endometrial cancer cell lines. First is to understand whether AE-CA has cell toxicity in endometrial cancer cell lines. Thus we chose three endometrial cancer cell lines (HEC1A, HEC1B, KLE) for in vitro experiment, and observed the cell morphology change after AE-CA treatment. The effects of AE-CA on the induction of cell cycle arrest, the accumulation of cyclin-A2 and -B1, and the activation of caspase-3 and caspase-7 were similar to those of CPT. Furthermore; AE-CA exhibited a synergistic effect on the cytotoxicity of cisplatin in HEC-1A and HEC-1B cells. These results indicated that AE-CA is a potent antitumor agent and can be combined with cisplatin for the treatment of human endometrial cancer.

並列關鍵字

Aqueous Extract of Campotheca Acuminata Decne ； Camptothecin ； human Endometrial cancer

參考文獻

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