| Abstract: | 癌症是國人十大死因之第一位,因此如何減少癌症之發生或惡化是一重要研究課題, 近年來誘發腫瘤細胞分化及抑制癌細胞或減緩癌細胞轉移之物質開發為癌症預防與治療開啟另一新方向。大部份癌細胞具有分化不佳且展現高度增生之特性,如能誘發分化讓不成熟、不正常或惡性之細胞反轉成正常或良性之細胞，使細胞呈現成熟細胞之表現型, 將可減少癌症之惡化。另外癌細胞轉移惡化是癌細胞致命的主因，其過程包括如癌細胞骨架的改變,打亂細胞與細胞間或細胞與間質之作用力,增加基質金屬蛋白酵素及血管新生因子的分泌進而促進細胞轉移，而這些作用可能與轉譯因子的活化有關，如能預防或減少這些現象之發生，將可延長癌症病患之壽命。天然物在人類預防保健中扮演重要角色,也是人類醫藥開發的寶藏，異黃酮(isoflavone) 、木質素(lignin) 及香豆雌酚 (coumestan)被稱為植物荷爾蒙(phytoestrogen),報導指出其對停經後婦女潮熱心悸、骨質流失、記憶力衰退等現象具有改善之作用，文獻也指出其具有抗菌、抗氧化、抗癌及保肝等活性，另外對於異黃酮衍生物抗癌活性之作用機制有較多的探討，而有關香豆雌酚衍生物之抗癌活性及其作用機制相對較少，香豆雌酚衍生物如coumestrol 主含於苜蓿芽中，最近我們在中草藥研究中發現黃花蟛蜞菊及旱蓮草中含有豐富香豆雌酚衍生物 wedelolactone，且預試驗中發現在無毒劑量處理下其可降低惡性乳癌細胞 MDA-MB-231(estrogen independent)在soft agar plate 之生長(by anchorage independent assay)及遷移現象(by wound healing assay) 亦即具有誘發分化與抑制轉移之潛能，因此我們想要進一步比較探討食材中香豆雌酚衍生物: coumestrol 與中草藥中香豆雌酚衍生物: wedelolactone 對惡性人類乳癌細胞、神經膠瘤細胞與肝癌細胞分化與惡化作用之影響以及作用機制之異同，主要研究如下: 第一年以人類乳癌細胞株MDA-MB-231 細胞進行in vitro and in vivo assay (1) coumestrol 與wedelolactone 對MDA-MB-231 乳癌細胞生長及分化之影響。 (2) coumestrol 與wedelolactone 對MDA-MB-231 乳癌細胞增生訊息相關路徑之分析及對生長調控蛋白影響之分析。 (3) coumestrol 與wedelolactone 對MDA-MB-231 乳癌細胞吸附、浸潤與侵移之作用分析及其相關調控分子或訊息路徑如MAPK, NFkB, FAK, integrin,MMP 及uPA 等蛋白之影響分析。 (4) 以裸鼠進行乳癌細胞轉移之動物評估觀測香豆雌酚衍生物之影響。第二年以人類U87 惡性神經膠瘤細胞株進行in vitro and in vivo assay 如第一年觀測coumestrol 與wedelolactone 對該細胞分化上之影響及其作用機制之探討;另外由體外及體內測試方法觀測香豆雌酚衍生物對U87 細胞之侵移與轉移之影響及其作用機制之探討. 第三年以人類肝癌細胞細胞株HepG2 細胞進行in vitro and in vivo assay 觀測coumestrol 與wedelolactone 對該細胞分化上之影響及其作用機制之探討;另以 HGF 誘發HepG2 肝癌細胞惡化現象，進而探討香豆雌酚衍生物對HGF 誘發侵移之影響及其作用機制之探討.
The broad classes of phytoestrogen compounds include isoflavonoids, coumestans, lignans, and stibenes. Epidemiologic evidence supports a protective effect of high phytoestrogen diets to reduce the incidence of certain cancers, such as breast and prostate cancer. Much of the epidemiologic studies have focused on isoflavones. In addition to coumestrol, Wedelolactone, a coumestan derivative, was first isolated from the extract of Wedlia calandulaceae in 1956 and later from Eclipta prostrate. Wedelolactone exhibits a broad range of biological activities including antidote for snake venom, beneficial effects in liver disease, and stimulation of liver cell regeneration and direct inhibition of IKK complex. However, it is not well known about anti-tumor progression effect of coumenstan derivatives. Strategically targeted cancer therapies are emerging from enormous efforts spent investigation basic signaling mechanisms involved in cell growth, cell death and metastasis pathways. Most cancer cells exhibit a defect in their capacity to mature into non-replicating adult cells, thereby existing in a highly proliferating state, which results in outgrowing their normal cellular counterparts. Cancer metastasis, the spread of cancer cells from the primary neoplasm to distant sites and their growth there is the major cause of death in various cancer patients. Metastasis of cancer cells involves multiple processes and various cytophysiological changes, including changes in adhesion capability between cells and extracellular matrix and abnormal intercellular interaction. Thus, degradation of the extracellular matrix and components of the basement membrane, caused by concerted action of proteinases, such as matrix metalloproteinases (MMPs) cathepsins, and plasminogen activator (PA), plays a critical role in tumor invasion and metastasis. In our preliminary study, it showed that coumestan derivative, wedelolactone decreased the anchorage-independent growth and the migration of MDA-MB-231 cells. Thereafter, it is interested to evaluate the anti-progression potential and to investigate as well as compare the action target of wedelolactone and coumestrol. The following subject will be studied: The first year: In vitro and In vivo effect and mechanism of wedelolactone and coumestrol on the invasive growth of MDA-MB-231 cells. The second year: In vitro and In vivo effect and mechanism of wedelolactone and coumestrol on the invasive growth of human glioma U87 cells. The third year: In vitro and In vivo effect and mechanism of wedelolactone and coumestrol on HGF-induced hepatoma HepG2 cells invasive growth. |
