Investigation of the angiogenic mechanism at the hepatic metastasis of the colorectal carcinoma.

肿瘤转移是一个复杂的多步骤过程。为了研究大鼠肝转移的复杂过程，我们建立了一套磁共振成像（MRI）系统（SIS200 /400）。我们从KM12SM人结直肠癌细胞系中通过体内筛选建立了多株高转移细胞系。在这些高度转移的细胞系中，我们通过流式细胞分析发现Siaryl Lewis^a在细胞表面的表达增加，E-cadherin在细胞表面的表达减少。这些结果已在一些会议和论文中报道。将RCN-9大鼠结肠癌细胞系肿瘤细胞注入F344大鼠门静脉。4周后用MRI观察肝转移情况。肝转移可通过T2加权像和钆增强T1加权像鉴别，但不能通过T1加权像鉴别。MRI对大鼠肝转移的定量评价有助于肝转移在体内的研究。动态MRI显示肿瘤处血液循环动力学。类维甲酸有抗血管生成的作用。我们研究了复合类维甲酸TAC101的抗转移作用。TAC101和ATRA抑制体外ECN-9的生长。TAC101在体内对模型大鼠肝转移有抑制作用，并在时间过程中通过MRI观察到这种现象。

Cancer metastasis is completed through complex and multistep processes. We developed an evaluate system of hepatic metastasis in rats by magnetic resonance imaging(MRI)(SIS200 /400) in time course to investigate this complex metstatic processes. We established several highly metastatic cell lines from KM12SM human colorectal carcinoma cell line by in vivo selection. In these highly metastatic celllines, we identified the increased expression of Siaryl Lewis^a and decreased expression of E-cadherin at cell surface by flow-cytometric analysis. These results were reported at some conferences and papors. The tumor cells of RCN-9 rat colon cancer cell line were injected into portal vein of F344 rats. After 4 weeks, the hepatic metastasis was observed and evaluated by using MRI.The hepatic metastasis was identified by T2 weighted images and gadrinium(Gd)-enhancedT1 weighted images, but not by T1 weighted images. The quantitative evaluation of the hepatic metastasis in rats by using MRI seems to be usefull for the study of hepatic tastasis in vivo. Dynamic MRI indicated the kinetics of blood circulation at the tumor. Retinoid has an anti-angiogenic effect. We investigated the anti-metastatic effect of a composite retinoid, TAC101. TAC101 and ATRA inhibited the growth of ECN-9 in vitro. TAC101 inhibited the hepatic metastasis of rat model in vivo, and this phenomenon was observed by MRI in time course.