肿瘤组织骨髓来源新生血管内皮和炎症细胞浸润动物模型的观察

Observation on Myeloid Origin of Neovascular Endothelial Cells and Infiltration of Bone Marrow-originated Inflammatory Cells in A Murine Tumor Model

背景与目的:肿瘤组织新生血管主要是靠宿主血管以出芽的方式形成,一些研究认为骨髓来源的内皮前体细胞(endothelial progenitor cells,EPCs)参与肿瘤组织血管的生成,而且肿瘤组织中骨髓来源的炎症细胞可能促进肿瘤的侵袭、血管生成和转移等。本实验旨在建立动物模型以观察骨髓来源的肿瘤组织新生血管内皮细胞,以及骨髓来源的炎症细胞在瘤组织中的浸润情况。方法:以绿色荧光蛋白(green fluorescent protein,GFP)转基因C57BL/6小鼠为供体提供骨髓,普通清洁级C57BL/6小鼠经60Co 8 Gy全身照射,24h后为受体进行骨髓移植,于移植2周后接种Lewis肺肿瘤细胞于受体小鼠腋下,待肿瘤直径达到1～2cm时,取肿瘤组织切片在荧光显微镜下直接观察肿瘤血管及炎症细胞,并结合免疫组化方法明确其种类和分布。结果:在荧光显微镜下可观察到散发不连续性绿色荧光的肿瘤血管内皮细胞和浸润的炎症细胞,经免疫组化测定染色大部分呈阳性。肿瘤细胞周边和内部坏死区可见大量巨噬细胞浸润;肿瘤间质和肿瘤细胞区散在分布着少量淋巴细胞。结论:肿瘤组织新生血管的部分内皮细胞来源于骨髓;这种动物模型可以作为观察肿瘤组织中骨髓来源细胞特异而直接的方法。

BACKGROUND ＆ OBJECTIVE. Some studies indicate that endothelial progenitor cells （EPCs） originated from the bone marrow participate in neoplastic angiogenesis, and that bone marrow origin of inflammatory cells potentially contribute to neoplastic invasion, angiogenesis and metastasis. This study was to observe the origin of neovascular endothelial cells and infiltration of bone marrow-originated inflammatory cells in a murine tumor model. METHODS： Healthy C57BL/6 mice were irradiated with ^60Co at 8 Gy. Bone marrow cells of green fluorescent protein （GFP） transgenic C57BL/6 mice （donators） were transplanted intravenously into C57BL/6 mice （recipients） via the tail vein 24 h after irradiation. Lewis lung tumor cells were inoculated subcutaneously into recipient mice 2 weeks after transplantation. The xenograft tumors were removed until their diameters reached approximately 1- 2 cm. Subsequently, tumor vessels and inflammatory cells were observed under fluorescent microscopy and detected using immunohistochemistry （IHC）. RESULTS： Unsuccessive green fluorescence emitted by neoplastic vascular endothelial cells and inflammatory cells was observed, most of which appeared positive IHC staining. A large number of macrophages were observed inside or adjacent to the necrotic areas of the tumor. A few lymphatic cells were mainly dispersed inside tumor stroma and tumor cells. CONCLUSIONS. Partial endothelial cells of neoplastic neovessels originate from the bone marrow. The murine tumor model could be used as a specific and direct approach to observe bone marrow-originated cells in neoplasms.