Research for molecular mechanisms of lymphangiogenesis and lymph node metastasis

1.淋巴标志物Podoplan in在肿瘤中的表达与淋巴结转移密切相关，我们建立了新型的抗人Podoplan in抗体，并利用组织芯片技术发现了其在多种癌细胞中的表达。2.同源盒基因PROX1是一个新的肿瘤抑制基因，我们发现PROX1的表达与肿瘤分化程度密切相关。随后，我们还发现PROX1在肿瘤中的低表达与预后不良密切相关。3.两组Thy1阳性的间充质细胞调节肝祖细胞的体外成熟。我们确定粘蛋白跨膜型糖蛋白gp38可以区分立方细胞和Spin…免疫细胞化学显示更多的中间细胞。Gp38阳性细胞促进的肝祖细胞体外成熟可能受到gp38阴性细胞的抑制作用，这可能维持了CD49f阳性细胞的未成熟的增殖状态。4.胚胎干细胞和淋巴管内皮细胞对OP9基质细胞的分化分化第3天由ES细胞分化为LEC的VEGFR-2^+细胞与OP9基质细胞的分化由PROX1、VEGFR-3和另一淋巴标志物podoplan in的表达决定。VEGFR-2^+细胞分化为LYVE-1~+胚胎ECs，第1天PROX1阴性，第3天转为PROX1~+LECs。VEGFR3-Fc或Tie2-Fc，封闭血管内皮生长因子-C或血管生成素1(Ang1)，抑制晶状体上皮细胞在OP9细胞上的集落形成。然而，在胶原包被的培养皿中加入血管内皮生长因子-C和血管紧张素1，联合应用于VEGFR-2^+细胞，并不能诱导晶状体上皮细胞。用该条件培养液在PFA固定的OP9细胞上完全复制了OP9细胞的LEC诱导活性。较少

1.The expression of lymphatic marker, podoplanin by cancer were associated with the frequency of lymph node metastasis.We established novel anti-human podoplanin antibodies, and found the expression by several cancer cells using tissue microarrays. We also found that podoplanin was the specific marker for mesothelioma.2.Homeobox gene, prox1 as a novel tumor suppressor gene.We found that there was a significant correlation between prox1 expression and the differentiation scores of the tumors. Subsequently, we also showed that low expression of prox1 in tumors was closely associated with a poor prognosis. The specific knockdown of prox1 by RNA interference strongly accelerated in vitro cell growth, while the over-expression of prox1 greatly suppressed the growth.3.Two populations of Thy1-positive mesenchymal cells regulate the in vitro maturation of hepatic progenitor cellsWe determined that the mucin-type transmembrane glycoprotein gp38 could distinguish the cuboidal cells from the spin … More dle cells by immunocytochemistry. In vitro maturation of hepatic progenitor cells promoted by gp38-positive cells may be opposed by an inhibitory effect of gp38-negative cells, which likely maintain the immature, proliferative state of CD49f-positive cells.4.Differentiation of lymphatic endothelial cells from Embryonic Stem cells on OP9 stromal cellsVEGFR-2^+ cells derived from ES cells differentiated into LECs at day3 on OP9 stromal cells defined by the expression of prox1, VEGFR-3 and another lymphatic marker podoplanin. VEGFR-2^+ cells gave rise to LYVE-1^+ embryonic ECs, which were negative for prox1 on day1 but turned to prox1^+ LECs by day3. VEGFR3-Fc or Tie2-Fc, sequestering VEGF-C or angiopoietin 1 (Ang1), suppressed colony formation of LECs on OP9 cells. However, addition of VEGF-C and Ang1 in combination with VEGF to the culture of VEGFR-2^+ cells on collagen-coated dishes failed to induce LECs. LEC inducing activity of OP9 cells was fully reproduced on PFA-fixed OP9 cells with the conditioned medium. Less