木犀草素與槲皮素對A431表皮癌細胞的上皮-間葉移轉之反轉作用

Abstract

高入侵性的A431-III癌細胞是從原A431子宮頸上皮癌細胞(A431-P)經由三次穿透以matrigel覆蓋在Boyden chamber的濾膜上而篩選出來的。這樣的A431-III細胞具有高入侵性主要是基於其擁有較強的貼附力、展開及移動能力，同時也能表現較多的基質金屬蛋白酶(MMP)以增加其活性。透過比較A431-P與A431-III的差異來探討癌細胞的上皮-間葉移轉(EMT)過程，可以當做一個模型來了解細胞的腫瘤轉移過程。利用這個方式，我們在A431-P/III的模型中有效的測試木犀草素(luteolin)與槲皮素(quercetin)的抗癌能力。我們發現在高入侵性的A431-III癌細胞中，這兩種食物中的類黃酮素(flavonoids)可以反轉腫瘤發展中的cadherin switch、降低上皮-間葉移轉標的物(EMT markers)的表現以及減緩其入侵能力。接著我們在A431-P細胞中短暫的超量表現MMP-9也可促使細胞走向上皮-間葉移轉(EMT)，並且在超量表現MMP-9的細胞中加入木犀草素(luteolin)與槲皮素(quercetin)發現可以有效的反轉MMP-9所造成的上皮-間葉移轉(EMT)現象。此外，以表皮生長因子(EGF, 100 ng/mL)及類黃酮素(10 μM of Lu or Qu)共同添加於A431-P或A431-III細胞中，也可以看到木犀草素(luteolin)與槲皮素(quercetin)可以使細胞走向表皮細胞的特徵，並且降低EGF所誘導的上皮-間葉移轉標的物(EMT markers)表現及重建細胞與細胞的接合(cell-cell junctions)。其中的E-cadherin的表現會被EGF所減弱但可以被木犀草素(luteolin)與槲皮素(quercetin)所增強。我們在這篇論文的研究數據可以推測木犀草素(luteolin)與槲皮素(quercetin)是有潛力且良好的藥物用來截斷和預防上表皮癌細胞之上皮-間葉移轉(EMT)的發生並且對於減少A431-III癌細胞的腫瘤發展有明顯的活性。就結論來說，木犀草素(luteolin)與槲皮素(quercetin)可以透過反轉癌細胞的上皮-間葉移轉(EMT)，其對於減弱腫瘤發展俱有內在的潛力及功效可用來當作化學預防和抗腫瘤的藥物。

Highly invasive A431-III cells, which are derived from parental A431-P cells, were originally isolated via three successive passages through a Boyden chamber using a Matrigel-coated membrane support. The greater invasion potential exhibited by A431-III cells was due to their increased ability to spread/migrate, which was associated with enhanced MMP activity. The tumor progression events evoked by A431-P cells compared to A431-III cells may help identify useful strategies for evaluating the EMT and these cell lines could be a reliable model for evaluating tumor metastasis events. Employing this approach, we evaluated the effects of luteolin and quercetin using the A431-P/A431-III EMT model. These flavonoids reversed cadherin switching, downregulated EMT markers and nullified the invasion ability of A431-III cells. Overexpression of MMP-9 resulted in induction of the EMT in A431-P cells and this could be reversed by treating with luteolin or quercetin. Co-treatment of A431-P and A431-III cells with EGF plus luteolin or quercetin resulted in a more epithelial-like morphology, led to reduced levels of the EGF-induced markers of the EMT and caused the restoration of cell-cell junctions. E-cadherin was decreased by EGF, but increased by luteolin and quercetin. Our results suggest that luteolin and quercetin are potentially beneficial agents that target and prevent the occurrence of the EMT in epidermal carcinoma cells. These chemicals also have the ability to attenuate tumor progression in A431-III cells. In conclusion, luteolin and quercetin show inherent potential as chemopreventive/anti-neoplastic agents and do this by abating tumor progression through a reversal of EMT.