Gene Targeting Therapy against tumor endothelial cells

肿瘤是一种遗传性疾病，已经进行了针对癌细胞的基因靶向治疗。然而肿瘤基因异常复杂，单基因治疗难以提高肿瘤治疗效率，另一方面，肿瘤间质血管新生对肿瘤的生存和生长至关重要，因此干扰肿瘤间质血管新生的治疗是肿瘤治疗的有效方法。然而，希达等报道，通过从人肿瘤的口腔异种移植模型中分离肿瘤内皮细胞，发现肿瘤内皮细胞与正常内皮细胞相比具有遗传学上的差异，我们用磁珠法从口腔癌、肾癌和肺癌的手术材料中建立人肿瘤内皮细胞。这些细胞表达CD 34和CD 131，并被证实为内皮细胞。提取RNA并进行DNA微阵列，我们已经鉴定了70个在肿瘤内皮细胞中上调的基因。通过实时荧光定量RT-PCR、Western blotting和免疫荧光分析证实了这些基因产物的表达。通过将siRNA引入细胞中来抑制肿瘤内皮细胞的增殖。此外，我们发现考克斯-2抑制剂可选择性地抑制肿瘤内皮细胞的运动和增殖活性，这些结果提示靶向肿瘤内皮细胞对肿瘤治疗具有重要意义。

Tumor is a genetic disorder, and gene targeting therapy for cancer cells has been conducted. However, tumor gene abnormalities arre complicated, and it is quite difficult to improve efficiency of cancer treatment targeting single gene product.On the other hand, since neovasculization in tumor stroma is essential for tumor survival and Growth, therapy for disturbing neovasculaizaion would be effective in cancer therapy.It has been considered that the blood vessels in tumor stroma was composed of normal endothelial cells; however, Hida et al. have reported that tumor endothelial cells have genetically varied character compared to the normal endothelial cells by isolation of tumor endothelial cells from mouth xenograft models of human cancers.We established human tumor endothelial cells by using magnetic beads method from the operation materials of oral carcinoma, renal carcinoma and lung carcinoma. These cells express CD34 and CD131, and confirmed as endothelial cells. RNA was extracted and DNA microarray has been carried out, and we have identified 70 genes that were upregulated in tumor endothelial cells. We confirmed the expression of these gene product by real-time RT-PCR, Western blotting and immunohistochemisty. Proliferation of tumor endothelial cells was decreased by introducing siRNA into the cells. In addition, we found that motility and proliferative activity of tumor endothelial cells were selectively decreased by Cox-2 inhibitor treatment.These results imply the significance of targeting tumor endothelial cells for favorable cancer therapy.