UMDNJ-School of Osteopathic Medicine, Camden, NJ, USA.
Curr Med Chem. 2012;19(35):6036-49. doi: 10.2174/092986712804485863.
The evidence seems to be growing in favor of the stem cell theory of cancer with the emergence of studies demonstrating the parallel mechanisms of self renewing pathways in stem cells and particular subsets of cancer cells. The finding of leukemia stem cells and subsequently breast cancer stem cells (BCSC) further supports the concept. The importance of these findings lends itself to the selfrenewal properties of stem cells in addition to the survival characteristics of stem cells, mechanisms that will have to be overcome when creating treatment modalities. In particular, research has shown that stem cells and a specific type of stem cells, mesenchymal stem cells (MSC), have special drug effluxing properties and some interactions with particular cells of the immune system that may serve major roles in immunosuppresion and overall tumor cell survival. Furthermore, the recent discovery of epithelial to mesenchymal transition (EMT) has laid out a possible mechanism for tumor cells to lose particular phenotypic epithelial cell markers and gain phenotypic mesenchymal cell markers. This process is implicated in metastasis in addition to overall tumor survival and evasion of the immune system. This review examines the current understanding of how tumor cells evade the immune system, but will first explore stem cells, cancer stem cells, normal immune interaction with tumor cells, and EMT.
越来越多的证据支持癌症干细胞理论，这些证据来自于研究表明干细胞和特定类型的癌细胞自我更新途径的平行机制。白血病干细胞和随后的乳腺癌干细胞（BCSC）的发现进一步支持了这一概念。这些发现的重要性除了干细胞的生存特性外，还涉及到干细胞的自我更新特性，这将是在创建治疗方式时必须克服的机制。特别是，研究表明，干细胞和一种特定类型的干细胞，间充质干细胞（MSC），具有特殊的药物外排特性，并且与免疫系统的特定细胞有一些相互作用，这些作用可能在免疫抑制和肿瘤细胞整体存活中起主要作用。此外，最近发现的上皮间质转化（EMT）为肿瘤细胞失去特定的表型上皮细胞标记并获得表型间充质细胞标记提供了一种可能的机制。这个过程不仅与肿瘤的整体存活和逃避免疫系统有关，还与转移有关。这篇综述探讨了肿瘤细胞如何逃避免疫系统的现有理解，但首先将探讨干细胞、癌症干细胞、正常免疫与肿瘤细胞的相互作用以及 EMT。
