Department of Differentiation and Cancer, Centre de Regulació Genòmica (CRG), Universitat Pompeu Fabra, Barcelona, Spain.
Cell Death Dis. 2011 Sep 1;2(9):e204. doi: 10.1038/cddis.2011.84.
Polycomb group proteins have long been linked to the occurrence of different forms of cancer. Polycomb proteins form at least two distinct complexes, the Polycomb-repressive complexes 1 and 2 (PRC1 and PRC2). Some of the PRC complex subunits have been found to be overexpressed in a variety of different tumors. Epigenetic perturbations are likely to be the cause for transcriptional misregulation of tumor suppressor genes and of certain cell fates. It is especially critical for stem cells that their potential to self-renewal and to differentiate is tightly controlled and properly orchestrated. Misregulation of Polycomb protein levels often leads to either a block or unscheduled activation of developmental pathways, thereby enhancing the proliferation capability of a cell. The consequences of this misregulation have been linked to the establishment of cancer stem cells, which can produce tumors through a combination of increased self-renewal and the lack of complete cellular differentiation. Cancer stem cells are believed to persist within tumors and to elicit relapse and metastasis. In this review, we recapitulate the roles of Polycomb proteins in stem cell biology, and the impact their misregulation can have on cancer.
多梳蛋白（PcG）家族蛋白与多种形式的癌症的发生有着长期的联系。PcG 蛋白至少形成两种不同的复合物，多梳抑制复合物 1 和 2（PRC1 和 PRC2）。在各种不同的肿瘤中发现一些 PRC 复合物亚基过表达。表观遗传的改变可能是肿瘤抑制基因和某些细胞命运转录调控失调的原因。干细胞的自我更新和分化的潜力受到严格控制和适当协调，这一点尤为重要。PcG 蛋白水平的失调通常导致发育途径的阻滞或无调度激活，从而增强细胞的增殖能力。这种失调的后果与癌症干细胞的建立有关，癌症干细胞可以通过增加自我更新和缺乏完全细胞分化的组合来产生肿瘤。癌症干细胞被认为存在于肿瘤中，并引发复发和转移。在这篇综述中，我们总结了 PcG 蛋白在干细胞生物学中的作用，以及它们失调对癌症的影响。
