侵袭和转移是恶性肿瘤的特征。由于人们对这些行为的分子水平机制了解甚少,分析的方法也就较粗糙。侵袭是组织屏障的丧失并伴随瘤细胞侵入邻近组织;转移是侵袭细胞进入血管或淋巴管,存活在血管内并沿管道运行,粘附在毛细血管壁上,游出毛细血管腔,并在远处生长成瘤。多数研究方法需将肿瘤和宿主在体内或体外条件下相接触,这种接触方式不同于肿瘤发展的自然过程。后者可能是单个瘤 Invasion and metastasis are features of malignant tumors. Because people know very little about the molecular level mechanisms of these behaviors, the methods of analysis are also relatively crude. Invasion is the loss of a tissue barrier and is accompanied by invasion of tumor cells into adjacent tissues; metastasis is the invasion of cells into the blood or lymphatic vessels, survival within the blood vessels and along the pipeline, adhesion to the capillary wall, swimming out of the capillary lumen, and in the far The tumor grows. Most research methods require the tumor and the host to be contacted in vivo or in vitro. This contact method is different from the natural process of tumor development. The latter may be a single tumor