Molecular Cancer Biology Program & Department of Pathology, University of Helsinki, Helsinki, Finland.
J Mol Cell Cardiol. 2011 Feb;50(2):290-5. doi: 10.1016/j.yjmcc.2010.10.024. Epub 2010 Nov 1.
Contribution from diverse tissue-specific stem cell types is required to create the cell populations necessary for the activation of angiogenesis and neovascular growth in cancer. Bone marrow (BM)-derived circulating endothelial progenitors (EPCs) that would differentiate to bona fide endothelial cells (ECs) were previously believed to be necessary for tumor angiogenesis. However, numerous recent studies demonstrate that EPCs are not needed for tumor angiogenesis and indicate EPCs to be artifactual rather than physiological. It is evident that tumor infiltrating hematopoietic cells produced by BM-residing hematopoietic stem cells (HSCs) may contribute to tumor angiogenesis in a paracrine manner by stimulating ECs or by remodeling the extracellular matrix. Therefore, identification of the various hematopoietic cell subpopulations that are critical for tumor angiogenesis and better understanding of their proangiogenic functions and mechanisms of action have potential therapeutic significance. Stem and progenitor cell subsets for also other vascular or perivascular cell types such as pericytes or mesenchymal/stromal cells may provide critical contributions to the growing neovasculature. Furthermore, we hypothesize that the existence of a yet undiscovered-and largely unsearched-tissue-specific adult vascular endothelial stem cell (VESC) would provide completely novel targeted approaches to block pathological angiogenesis and cancer growth. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".
不同组织特异性干细胞类型的贡献对于产生激活癌症血管生成和新血管生长所必需的细胞群体是必要的。以前认为骨髓（BM）来源的循环内皮祖细胞（EPC）分化为真正的内皮细胞（EC）对于肿瘤血管生成是必要的。然而，最近的许多研究表明，EPC 对于肿瘤血管生成不是必需的，并表明 EPC 是人为的而不是生理性的。显然，由驻留于骨髓中的造血干细胞（HSC）产生的浸润肿瘤的造血细胞可能通过刺激 EC 或重塑细胞外基质以旁分泌的方式促进肿瘤血管生成。因此，鉴定对于肿瘤血管生成至关重要的各种造血细胞亚群，并更好地了解它们的促血管生成功能和作用机制具有潜在的治疗意义。对于其他血管或血管周细胞类型（如周细胞或间充质/基质细胞）的干细胞和祖细胞亚群也可能为不断增长的新血管提供关键贡献。此外，我们假设存在尚未发现的——并且在很大程度上未被探索的——组织特异性成年血管内皮干细胞（VESC），这将为阻断病理性血管生成和癌症生长提供全新的靶向方法。本文是题为“心血管干细胞再探讨”的特刊的一部分。
