Analyses of tumor angiogenesis and development of antiangiogenic gene therxpy

1.从微结构角度分析肿瘤血管生成血管内皮生长因子在肿瘤血管生成中起核心作用。在以人纤维肉瘤HT1080细胞为模型的小鼠肿瘤模型中，我们用透射电子显微镜观察了肿瘤血管生成的形态特征和重塑模式。血管内皮生长因子基因转染组肿瘤血管生成旺盛。在发芽、管腔分裂和套叠微血管生长三种类型的血管生成中，导致发芽的管腔突起数目显著高于对照肿瘤。血管内皮生长因子转染组血管内皮细胞的壁细胞覆盖率明显降低。采用CD34和α-SMA免疫组织化学双重染色方法，检测结肠癌临床标本中微血管密度和微血管周细胞覆盖指数。高微血管密度组预后较差，尤其是…高MVD组和低MPI组的表达更多。这些结果表明，内皮细胞和周细胞的相互作用在肿瘤血管生成中起关键作用。抗血管生成基因治疗肿瘤的研究进展我们报道了利用HVJ阳离子脂质体将小鼠巨噬细胞金属弹性酶(MME)基因重复体内转导到CT-26小鼠结肠癌的肿瘤中，通过抑制血管生成的机制抑制了肿瘤的生长。我们报道了在RCN-9大鼠结肠癌创面复发模型中，应用血管内皮生长因子受体可溶型Flt-1的自体成纤维细胞，抑制了肿瘤的生长并延长了生存时间。肝细胞癌MVD显著高于转移性肝癌，HK II显著高于转移性肝癌。我们正在开发一种低氧诱导自杀基因系统，用于治疗血管生成非依赖性肿瘤

1. Analyses of tumor angiogenesis from the viewpoint of microstructureVascular endothelial growth factor (VEGF) plays a central role in tumor angiogenesis. In a mouse tumor model using VEGF-transfected HT1080 human fibrosarcoma cell, we investigated morphological features and remodeling patterns of tumor angiogenesis by transmission electron microscope. VEGF-transfected tumors showed vigorous angiogenesis. Among three types of angiogenesis, I.e., sprouting, luminal division and intussusceptive microvascular growth, the number of abluminal processes leading to sprouting was significantly higher than control tumors. Mural cell coverage of endothelial cells was singificantly smaller in VEGF-transfectant. We evaluated microvessel density (MVD) and microvessel pericyte coverage index (MPI) using clinical specimen of colon cancer by immunohistochemical double staining with CD34 and α-SMA against endothelial cell and pericyte, respectively. The prognosis was poor in high-MVD group, especially … More , in high-MVD and low-MPI group. These results suggested that the interaction of endothelial cell and pericyte was a key role in tumor angiogenesis2. Development of antiangiogenic gene therapy for cancerWe reported that repeated in vivo transduction of mouse macrophage metalloelastase (MME) gene directly into the tumor of CT-26 mouse colon cancer using HVJ-cationic liposomes suppressed the tumor growth by an antiangiogenic mechanismWe reported that administration of autologous fibroblasts transfected with soluble form of Flt-1, a VEGF receptor, suppressed the tumor growth and prolonged the survival in the wound recurrence model of RCN-9 rat colon cancerWe investigated MVD representing aerobic metabolism and expression of hexiokinase II mRNA (HK II) representing anaerobic metabolism using clinical specimens of hepatocellular carcinoma and metastatic liver cancer from colon. MVD was significantly higher in hepatocellular carcinoma and HK II was significantly higher in metastatic liver cancer. We are developing a hypoxia-induced suicide gene system for treatment of angiogenesis-independent tumor Less