| Abstract: | Cisplatin是一種廣泛使用於多種癌症的化療藥物，儘管其抑制癌細胞生長的效果良好，但它的副作用包括骨髓抑制作用，限制了它的使用。我們的預備研究發現，雖然經口給予quercetin (1% quercetin飼料)未顯著增加cisplatin抑制移植A549細胞的tumor -bearing裸鼠身上腫瘤生長的效果，但由口給予quercetin和腹腔注射quercetin (i.p.; 10 mg/kg body weight, 3 times/week)一樣，顯著抑制2 mg cisplatin所引起的骨髓細胞下降作用。不過，quercetin對cisplatin的骨髓及血球細胞抑制作用的系統性影響及機制尚不清楚。此外，許多研究顯示地瓜(Ipomoea batatas)葉，一種台灣常見的蔬菜，及其萃出物可能具有多種生理功效，包括抗腫瘤，我們的預備研究測定數種台灣常見的蔬菜中quercetin含量，也發現地瓜葉的quercetin含量最高(約為洋蔥的7倍)，不過，地瓜葉及其萃出物是否對cisplatin的抗腫瘤及骨髓抑制作用有影響亦不清楚。 因此，在這個三年期的研究計畫，我們預備以tumor-bearing裸鼠(皮下注射A549細胞)，正常的小鼠及細胞培養來研究上述提出來的問題。本計畫的主要目的： 1. 第一年：以tumor-bearing裸鼠及正常的小鼠，檢測quercetin對cisplatin的骨髓及血球細胞抑制作用的系統性影響。我們將收集動物血液、骨髓及脾臟檢測各種免疫細胞、血球細胞之細胞數，骨髓細胞的細胞週期及凋亡情形，造血幹細胞的比例及促進造血因子(stem cell factor, granulocyote-macrophage colony-stimulating factor, interleukin-3 and interleukin-9)及抑制造血因子的含量(TGF-β and TNF-α)，此外也以體外實驗檢測骨髓細胞的colony-forming unit。 2. 第二年:以細胞株或初代骨髓細胞研究quercetin及quercetin-3-glucuronide (Q3G)對IL-9及phosphatidylinositol 3-kinase (PI3K)對cisplatin誘發的骨髓抑制作用。根據我們的預備研究及其他先前的研究，我們提出假說: quercetin及Q3G會藉由增加IL-9表現，而增加骨髓細胞生長，並藉由抑制PI3K抑制cisplatin誘發的細胞死亡。不過需要進一步的研究來證實此一假說。 3. 第三年:我們預備分別研究地瓜葉及其萃出物對cisplatin腫瘤抑制及骨髓抑制效應的影響，我們亦以tumor-bearing裸鼠進行此研究，我們的假說是: 地瓜葉及其萃出物能增加cisplatin抑制腫瘤的效果並降低其副作用。 本計畫的研究結果，應能提供以quercetin、地瓜葉或其萃出物作為具細胞毒性之化療藥劑--如cisplatin之輔助處理的進一步證據。
Cisplatin is a widely used chemotherapy drug for various tumors. Despite its significant anticancer activity, the side effects of cisplatin, including myelosuppression, limit its use. Our preliminary study showed that quercetin given intraperitoneally (i.p., 10 mg/kg B.W., 3 times/week) and orally (1% quercetin diet) significantly and similarly increased the bone marrow cell numbers, which were decreased by cisplatin (2 mg/kg B.W., once per week). However, the systematical effects of quercetin on cisplatin-induced myelosuppression and the possible mechanisms remain unclear. In addition, sweet potato (Ipomoea batatas) leaf, a common consumed vegetable in Taiwan, and its extract have been shown to possess several health-beneficial effects, including anti-tumor. Our preliminary study showed that sweet potato leaves had the highest quercetin level (about 7-fold higher than onion) among several common vegetables in Taiwan. However, whether sweet potato leaf or its extract modulates the anti-tumor effect and myelosuppressive effect of cisplatin is also unknown. Thus, in this three-year proposal, using tumor-bearing nude mice (subcutaneously injected with human lung cancer cells A549), normal mice and in vitro cell studies, we will investigate the questions mentioned above. The major purpose of this proposal will be: 1. In the first year, using tumor-bearing nude mice or normal mice, we will examine the systematical effects of quercetin on cisplatin-induced myelosuppression. We will collect blood, bone marrow, and spleen to determine the number of various immune cells and blood cells, cell cycle and apoptosis of bone marrow nucleated cells, the ration of hematopoietic stem cells as well as the levels of hematopoietic growth factors (stem cell factor, granulocyte-macrophage colony-stimulating factor, interleukin-3 and interleukin-9) and hematopoietic inhibitory factors (TGF-β and TNF-α). In addition, the numbers of colony-forming unit of bone marrow cells will be measured in vitro. 2. In the second year, using a cell line or primary bone marrow cells, we will investigate the role of IL-9 and phosphatidylinositol 3-kinase (PI3K) in the effect of quercetin and quercetin-3-glucuronide (Q3G) on cisplatin-induced myelosuppression. According to our preliminary study and other previous studies, we hypothesize that quercetin and Q3G increase the growth of bone marrow cell growth through upregulation of IL-9 expression and decrease cisplatin-induced cell death through inhibition of PI3K. However, further studies are warranted to prove the hypothesis. 3. In the third year, we will investigate the effects of sweet potato leaf and its extract, separately, on the anti-tumor and myelosuppressive effects of cisplatin. We will also use tumor-bearing mice to carry out the studies. We hypothesize that sweet potato leaf or its extract enhances the anti-tumor effect of cisplatin and attenuates the side effects of cisplatin. The results of this proposed study could provide further evidence for using quercetin, sweet potato leaf or its extract as an adjunctive treatment for cisplatin. |
