銀合歡種子內含成份Mimosine在活體動物抗癌效果之研究

洪文俊
高雄醫學院
細胞的增生主要由週期素與週期素依賴型蛋白激脢來調控。目前的研究發現藉由阻斷週期素的合成或增加週期素依賴型蛋白激脢抑制蛋白的生成，皆可有效的抑制癌細胞的增生甚至引發癌細胞的凋亡。我們實驗室去年的研究結果顯示mimosine，一種由銀合歡種子萃取出的植物特有的氨基酸，可以藉由不同的分子機轉來阻斷肺癌及肝癌細胞的生長。Mimosine在某些癌細胞株可以有效抑制週期素Dl的合成，在其他的癌細胞株則會增進週期素依賴型蛋白激脢抑制蛋白p2lWAF-1或p27KIP-l的表現。同時，mimosine可具有引發肺癌與肝癌細胞凋亡的效果。綜合多項試管內的實驗結果發現此氨基酸具有抗癌效果。為評估mimosine在活體動物內是否具有相同的抗癌效果，本研究以裸鼠為活體研究動物植入肺癌及肝癌細胞後，再單獨給予不同劑量的mimosine或合併使用臨床上常用之化學治癌藥物來進行治療，觀察腫瘤細胞生長的變化及其內在的基因表現，以評估mimosine的臨床實用性。
關鍵字：Mimosine、週期素、週期素依賴型蛋白激脢

Study of the anti-cancer effect of mimosine in vivo

Hung Wen-Chun
Technology of Medical Sciences, Kaohsiung Medical College
Cell proliferation is controlled by cyclins and cyclin-dependent kinases (CDKs). Recent study have demonstrated that inhibition of synthesis of cyclins or enhancement of synthesis of CDK inhibitors may lead to growth arrest or apoptosis in cancer cells. Our data indicated that mimosine, a natural plant amino acid extracted from Leucaena Glauca Benth, may inhibit cell proliferation of lung cancer and liver cancer cells by different mechanisms. Mimosine effectively blocks cyclin D1 synthesis in several cancer cell lines, while it augments CDK inhibitor, P21WAF-1 and P27KIP-1 synthesis in other cancer cell lines. Additionally, mimosine induced apoptosis in these cancer cell lines. Consider together, we conclude that mimosine is a potent anti-cancer agent in vitro. To clarify whether mimosine also elicits potent anti-cancer effect in vivo. We use nude mice as a model system to study the effect of mimosine in vivo in this study. In this study, mimosine was given into experimental animals in
關鍵字：Mimosine, cyclins, cyclin-dependent kinases