Relationship of cellular adhesive molecules and angiogenesis with oral squamous cell carcinoma.

E-cadherin表达的缺失已被证明与许多类型的癌的侵袭和转移相关。我们从口腔鳞状细胞癌（SCC）中建立了E-钙粘蛋白阳性（HOC 719-PE）和阴性（HOC 719-NE）克隆。HOC 719-PE细胞呈上皮样形态，细胞膜上有E-cadherin表达，而HOC 719-NE细胞呈成纤维细胞样形态，无E-cadherin表达。在体外侵袭实验和三维培养中，HOC 719-NE细胞的侵袭能力明显高于HOC 719-PE细胞。这些细胞表达的a-和b-连环蛋白的mRNA水平相似。然而，HOC 719-NE细胞，而不是HOC 719-PE细胞，显示出snail的强表达，snail是一种与上皮细胞分化成间充质表型有关的转录因子。snail和E-cadherin的这种反向表达在其他SCC细胞中进一步观察到，包括HOC 313和我们先前报道的不表达E-cadherin蛋白的大津细胞。的 ...更多信息 这些结果表明snail的表达在SCC侵袭性和转移性的获得中起着关键作用，我们报道的克隆将为理解SCC从上皮细胞向间质细胞转化的机制提供有用的工具。已经描述了血管生成在癌症生长和转移中的重要性。据认为，抑制血管生成将导致抑制癌症生长和转移。在这些概念的基础上，许多抗血管生成剂已经被研究，并且使用抗血管生成剂的新的化学疗法是有希望的。在这项研究中，我们显示了来自口腔鳞状细胞癌（SCC）细胞的条件培养基的血管生成活性和已知诱导这些细胞中的血管生成的几种生长因子的表达。在此基础上，我们研究了抗血管生成药物TNP-470对严重联合免疫缺陷（SCID）小鼠口腔鳞状细胞癌（SCC）生长的影响，结果表明，TNP-470对皮下接种于SCID小鼠的口腔SCC细胞HSC-2的生长有明显的抑制作用，并呈剂量依赖性。通过免疫组织化学观察到用TNP-470处理的癌组织周围的微血管减少。TNP-470高剂量（50 mg/kg）给药期间，除体重一过性下降外，未见明显毒副作用。TNP-470对7种口腔鳞癌细胞、12种其他癌细胞、成纤维细胞、正常上皮角质形成细胞和内皮细胞等22种细胞均有抑制作用。然而，内皮细胞对TNP-470的敏感性是所有其他细胞的1000倍以上。TNP-470可诱导内皮细胞和口腔鳞癌细胞发生G_1期阻滞，但对口腔鳞癌细胞的作用需要比内皮细胞高1000倍的浓度。[^3H]-TNP-470结合实验表明，内皮细胞与其他细胞之间TNP-470受体的数量和亲和力无明显差异。已报道TNP-470结合的甲硫氨酸氨基肽酶2（MetAP-2）的基因表达水平相似，结果提示，TNP-470等抗血管生成药物治疗口腔癌可能是一种有效的新疗法，并提示TNP-470对内皮细胞的特异性侵袭作用可能与TNP-470对口腔癌的治疗作用有关。TNP-470的特异性可能不是由于TNP-470的受体数量和亲和力更高，而是由于TNP-470的特异性靶分子的存在。少

The loss of E-cadherin expression has been shown to correlate to the invasion and metastasis of many types of carcinomas. We estab Iished E-cadherin positive(HOC719-PE)and negative(HOC719-NE)clones from an oral squamous cell carcinoma(SCC). HOC719-PE cells showed epithelial morphology with E-cadherin expression in the cell membrane, whereas HOC719-NE cells demonstrated fibro blastic morphology without E-cadherin expression. In invasion assay and three dimensional culture, HOC719-NE showed much higher invasivce ability than HOC719-PE cells. These cells expressed similar levels of mRNAs for a- and b-catenin. However, HOC719-NE cells, but not HOC719-PE cells, showed strong expression of snail, a transcription factor implicated in the di erentiation of epithelial cells into mesenchymal phenotype. This reverse expression of snail and E-cadherin was further observed in other SCC cells including HOC313, and TSU cells that we previously reported to show no expression of E-cadherin protein. The … More se results indicated that the expression of snail has a key role for the acquisition of more invasive and metastatic phenotypes of SCC and the clones we reported here will be useful tools for understanding the mechanism of the transition from epithelial to mesenchymal SCC cells.Angiogenesis refers to neovascularization from the existing vascular system. The importance of angiogenesis in cancer growth and metastasis has been described. It is thought that inhibition of angiogenesis will result in the inhibition of cancer growth and metastasis. On the basis of these concepts, many anti-angiogenic agents have been investigated and new chemotherapies using anti-angiogenic agents are promising. In this study, we showed the angiogenic activities of conditioned media derived from oral squamous cell carcinoma(SCC)cells and expression of several growth factors which are known to induce the angiogenesis in these cells. Then, we examined the effects of TNP-470, one of the most promising anti-angiogenic agents, on the growth of oral SCCs in severe combined immunodefi cient(SCID)mice and inculture.The growth of oral SCC cells, HSC-2, inoculated subcutaneously in SCID mice was inhibited in a dose dependent manner by the treat ment with TNP-470. A reduction of microvessels surrounding cancer tissue treated with TNP-470 was observed by immunohistochemistry. Significant side effects were not observed except for the transient weight loss during the period of treatment with high dose(50mg/kg)of TNP-470. TNP-470 inhibited the growth of all of the 22 kinds of cells including 7 oral SCC cells, and 12 other cancer cells, fibroblasts, normal epithelial keratinocytes and endothelial cells. However, the sensitivity of endothelial cells to TNP-470 was more than 1000 times higher than those of all other cells. G _1arrest on cell cycle was induced both in endothelial cells and oral SCC cells by the treatment with TNP-470, although 1000 times more concentration was needed for SCC cells compared with endothelial cells. Binding assay using[^3H]-TNP-470 revealed that there were no significant differences of numbers or affinities of receptors for TNP-470 between endothelial cells and othercells. Similar levels of the gene expression of methionine aminopeptidase 2(MetAP-2), which TNP-470 has been reported to bind, was seen in the endothelial cells and other cells.These results indicated that the treatment with anti-angiogenic agents such as TNP-470 may be effective as a new therapy for oral cancer and suggested that the specific infibition of endothelial cells by TNP-470 may be not due to the higher receptor number and affinity for TNP-470, but due to the existence of specific target molecules of TNP-470. Less