官真癀藉由調控細胞黏著分子抑制腎癌細胞的轉移

Abstract

腎細胞癌是一種極常見的腎臟腫瘤，佔所有惡性疾病的約百分之三，且其發生率在世界各地都有逐漸上升的趨勢，每年在台灣約有五百人因此死亡。大約有百分之三十的病患在診斷出罹患腎臟癌時已有癌細胞轉移的現象，近半數的患者即使接受腎切除手術仍有復發的情形。腎細胞癌對於一般的輻射療法、荷爾蒙療法、及化學療法都有非常頑強的抗性。 癌細胞轉移是造成病患死亡的一個主要原因，此時原位癌細胞會入侵鄰近組織滲入血管及淋巴管後轉移至其他部位。因此要阻止癌細胞轉移需要長期利用低毒性的藥劑去治療及抑制癌細胞的侵襲。而我們的研究主要是著重於尋找對於抑制腎癌細胞轉移具有前瞻性及發展性的抗癌中藥。藉由分析中藥完全抑制細胞生長濃度之五十 ( IC50 cell cytotoxicity ) 及完全抑制細胞遷移濃度之五十 ( IC50 cell migration )，由二十一種中藥中具低毒性且抑制細胞遷移高的官真癀 ( Aeginetia indica L., AIL ) 做進一步的研究。結果顯示官真癀可強效抑制786O細胞遷移、侵襲以及黏著的活性，且其對細胞的毒性低。 為了更深入的研究被官真癀影響的目標分子，我們偵測了一系列和轉移能力相關的指標性蛋白，藉由即時定量聚合酶連鎖反應以及西方墨點轉漬法分析，發現官真癀顯著地使ICAM-1 ( Intercellular adhesion molecule-1 ) 及N-cadherin的表現量下降。這些影響可能是藉由抑制Snail的表現及NF-κB 轉置到細胞核所造成的。另外，我們發現官真癀也抑制了Rac1的表現。 我們將786O細胞植入活體實驗鼠去檢測官真癀對於抑制腎細胞癌轉移的能力，藉由口服餵食NOD/SCID小鼠我們證實官真癀減少了786O細胞轉移至肺臟的能力，且對小鼠的體重沒有顯著的影響。綜合上述結果可以推論官真癀具有發展為治療腎細胞癌的抗癌新藥的潛力。

Renal cell carcinoma (RCC) is the most common type of kidney cancer accounting for 3% of all malignancies. It has been steadily increasing worldwide, and nearly 500 patients die of disease in Taiwan every year. At diagnosis, about 30% of the patients had metastasis disease, and nearly half the patients will have a recurrence after nephrectomy. RCC is resistant to conventional therapies such as radiation, hormone, and chemotherapy. Metastasis is the major cause of death in cancer patients, where cancer cells in the primary tumor invade surrounding tissues and penetrate into blood and lymphatic vessels, allowing them to reach distant sites. Antimetastatic therapy requires long-term treatment using agents with low cytotoxic activity to inhibit the invasion of cancer cells. Our research is focused on discovering promising lead anti-cancer Chinese Herbal Medicines (CHMs) that inhibit metastasis activity of renal cancer cells. By analysis of the IC50 cell cytotoxicity and IC50 cell migration of CHMs , we selected one of the best candidates, Aeginetia indica L. (AIL), for further investigation. Our results show that AIL exhibited higher inhibitory effects on cell migration, invasion, and adhesion activities of 786O cells, but low cytotoxicity. To further study the target molecule(s) affected by AIL, we measured the mRNA expression profile of a panel of several markers associated with metastasis. By using real-time quantitative RT-PCR analysis and western blot analysis, AIL showed a significant reduction of ICAM-1 and N-cadherin mRNA expressions. These inhibitory effects may be caused by the inhibition of snail expression and NF-κB nuclear translocation. On the other hand, Rac1 expression is also reduced significantly by AIL. Furthermore, we evaluated 786O cells in in vivo metastatic xenograph animal models to investigate the role of AIL in RCC metastases. And the results shows that AIL decreased the formation cells of lung metastasis of 786O when oral-administrated to NOD/SCID mice without adverse effect on the body weight. Our findings suggest that Aeginetia indica L. may be developed for the anticancer chemotherapy of RCC.