Barsky Sanford H, Mcphail Krista, Wang Justin, Dillard Jordan, Beard Crystal J, Ye Yin
Department of Pathology, Anatomy and Cell Biology and the Clinical and Translational Research Center of Excellence, Meharry Medical College, 1005 Dr. D.B. Todd Jr. Boulevard, Nashville, TN 37208, USA.
Star Diagnostics Laboratories, 215 E Warm Springs Rd, Ste 108, Las Vegas, NV 89119, USA.
Neoplasia. 2025 Feb;60:101127. doi: 10.1016/j.neo.2025.101127. Epub 2025 Jan 22.
Cancer stem cells in human tumors have been defined by stem cell markers, embryonal signaling pathways and characteristic biology, ie., namely the ability to repopulate the proliferating population. However, even if these properties can be demonstrated within a tumor cell subpopulation, it does not mean that they are truly hierarchical stem cells because they could have been derived from the proliferating population in a reversible manner.
Using a human PDX, Mary-X, that overall expressed a strong cancer stem cell phenotype, the study conducted both GPP-labelled retroviral transfection and fluorescent microsphere uptake studies to distinguish proliferating from dormant cells and array CGH to identify regions of amplifications (gains) and deletions (losses) on the overall Mary-X population and then applied derived probes by FISH on individual cells to identify a genomically stable subpopulation.
Whereas 97-99 % of the cells expressed retroviral GFP and not fluorescent particles and showed numerous gene amplifications and deletions, approximately 1-3 % of the cells showed the opposite. The subpopulation with the retained fluorescent microspheres and exhibiting genomic stability was significantly smaller in size than their GFP-expressing and genomically unstable counterparts. Sorting Mary-X spheroids on the basis of either CD133 or ALDH positivity further enriched for this subpopulation.
These studies indicate that a truly biological cancer stem cell subpopulation exists that exhibits both dormancy and genomic stability. This subpopulation could not have been derived from the proliferating and resulting genomically unstable population and therefore represents a truly hierarchical stem cell subpopulation capable of only unidirectional differentiation.
人类肿瘤中的癌症干细胞已通过干细胞标志物、胚胎信号通路和特征性生物学特性来定义，即重新填充增殖群体的能力。然而，即使这些特性能够在肿瘤细胞亚群中得到证实，也并不意味着它们是真正的层级干细胞，因为它们可能是以可逆的方式从增殖群体中衍生而来的。
利用总体上表现出强大癌症干细胞表型的人源肿瘤异种移植模型Mary-X，该研究进行了GPP标记的逆转录病毒转染和荧光微球摄取研究，以区分增殖细胞和休眠细胞，并进行了比较基因组杂交（array CGH），以识别整个Mary-X群体中的扩增（增益）和缺失（损失）区域，然后通过荧光原位杂交（FISH）在单个细胞上应用衍生探针，以识别基因组稳定的亚群。
虽然97%-99%的细胞表达逆转录病毒绿色荧光蛋白（GFP）而不表达荧光颗粒，并显示出大量基因扩增和缺失，但约1%-3% 的细胞表现出相反的情况。保留荧光微球并表现出基因组稳定性的亚群在大小上明显小于表达GFP且基因组不稳定的对应亚群。根据CD133或醛脱氢酶（ALDH）阳性对Mary-X球体进行分选，可进一步富集该亚群。
这些研究表明，存在一个真正具有生物学特性的癌症干细胞亚群，其表现出休眠和基因组稳定性。该亚群不可能源自增殖且基因组不稳定的群体，因此代表了一个真正的层级干细胞亚群，仅能够进行单向分化。
