Research for molecular mechanisms of lymphangiogenesis and lymph node metastasis

1.淋巴标志物podoplanin在肿瘤组织中的表达与淋巴结转移频率相关。我们建立了新的抗人podoplanin抗体，并利用组织芯片技术在几种癌细胞中发现了其表达。我们还发现podoplanin是间皮瘤的特异性标记物。同源盒基因，prox1作为一种新的肿瘤抑制基因。我们发现prox1的表达与肿瘤的分化评分有显著的相关性。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。2 .通过RNA干扰特异性敲低prox1可显著促进体外细胞生长，而过表达prox1则可显著抑制体外细胞生长。两群thy1阳性间充质细胞调节肝祖细胞的体外成熟。我们通过免疫细胞化学检测发现黏液型跨膜糖蛋白gp38可以区分立方细胞和自旋多细胞。gp38阳性细胞促进肝祖细胞的体外成熟可能会受到gp38阴性细胞的抑制作用的反对，这可能会维持cd49f阳性细胞的未成熟增殖状态。胚胎干细胞在OP9基质细胞上分化淋巴内皮细胞来源于ES细胞的vegfr -2^+细胞在OP9基质细胞上于第3天分化为LECs，由prox1、VEGFR-3和另一淋巴标记物podoplanin的表达决定。VEGFR-2^+细胞产生LYVE-1^+胚胎ECs，第1天prox1为阴性，第3天变为prox1^+ LECs。分离VEGF-C或血管生成素1 （Ang1）的VEGFR3-Fc或Tie2-Fc抑制了OP9细胞上LECs集落的形成。然而，在胶原包被培养皿中，将VEGF- c和Ang1联合VEGF加入到VEGFR-2^+细胞培养中，未能诱导出LECs。条件培养基在pfa固定的OP9细胞上完全复制了OP9细胞的LEC诱导活性。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