The First Faculty of Medicine, Institute of Histology and Embryology, Charles University Prague, Albertov 4, CZ-128 00 Prague, Czech Republic.
Biol Chem. 2009 Oct;390(10):985-94. doi: 10.1515/BC.2009.115.
Similar to growing and metabolically active tissues, tumors require a dense vasculature to gain access to oxygen and nutrients. However, blood vessels in tumors differ from vessels in normal tissues in many respects. In particular, the tumor vasculature is in an active state of angiogenesis or vasculogenesis, and it is immature and leaky. Blood vessels are multicellular tubes formed by polarized endothelial cells, which face the patent vascular lumen with their apical cell surface, whereas their basal cell surface faces extracellular matrix on the outside of the vessels. The same cell polarity can be found in other tubular structures, such as in the bronchial tubes of the lung or the kidney tubules. In contrast, blood vessels in invertebrates often have a vascular lumen lined by basal cell surfaces. These vessels are often formed by a process named 'ancestral vascular tube formation'. Here, we discuss the hypothesis that the supply of tumors with blood can be achieved by both endothelial cell-lined tubes as well as tubes formed by the tumor cells themselves using the ancestral vascular tube formation mechanism. We discuss this hypothesis with a particular focus on gastrointestinal tumors.
与生长和代谢活跃的组织类似，肿瘤需要密集的血管系统来获取氧气和营养。然而，肿瘤中的血管在许多方面与正常组织中的血管不同。特别是，肿瘤血管处于活跃的血管生成或血管发生状态，并且不成熟且渗漏。血管是由极化的内皮细胞形成的多细胞管，它们将其顶端细胞表面朝向有孔的血管腔，而它们的基底细胞表面朝向血管外部的细胞外基质。同样的细胞极性也可以在其他管状结构中找到，例如肺部的支气管或肾脏的肾小管。相比之下，无脊椎动物的血管通常由基底细胞表面衬里的血管腔组成。这些血管通常通过一种名为“祖血管管形成”的过程形成。在这里，我们提出了一个假设，即肿瘤的血液供应可以通过内皮细胞衬里的管以及肿瘤细胞本身利用祖血管管形成机制形成的管来实现。我们特别关注胃肠道肿瘤来讨论这个假设。
