Grasso Carole, Anaka Matthew, Hofmann Oliver, Sompallae Ramakrishna, Broadley Kate, Hide Winston, Berridge Michael V, Cebon Jonathan, Behren Andreas, McConnell Melanie J
Malaghan Institute of Medical Research, P.O. Box 7060, Wellington, 6242, New Zealand.
Ludwig Institute for Cancer Research, Olivia Newton-John Cancer & Wellness Centre, Austin Hospital, Heidelberg, VIC, 3084, Australia.
BMC Cancer. 2016 Sep 9;16(1):726. doi: 10.1186/s12885-016-2759-2.
The heterogeneity and tumourigenicity of metastatic melanoma is attributed to a cancer stem cell model, with CD133 considered to be a cancer stem cell marker in melanoma as well as other tumours, but its role has remained controversial.
We iteratively sorted CD133+ and CD133- cells from 3 metastatic melanoma cell lines, and observed tumourigenicity and phenotypic characteristics over 7 generations of serial xeno-transplantation in NOD/SCID mice.
We demonstrate that iterative sorting is required to make highly pure populations of CD133+ and CD133- cells from metastatic melanoma, and that these two populations have distinct characteristics not related to the cancer stem cell phenotype. In vitro, gene set enrichment analysis indicated CD133+ cells were related to a proliferative phenotype, whereas CD133- cells were of an invasive phenotype. However, in vivo, serial transplantation of CD133+ and CD133- tumours over 7 generations showed that both populations were equally able to initiate and propagate tumours. Despite this, both populations remained phenotypically distinct, with CD133- cells only able to express CD133 in vivo and not in vitro. Loss of CD133 from the surface of a CD133+ cell was observed in vitro and in vivo, however CD133- cells derived from CD133+ retained the CD133+ phenotype, even in the presence of signals from the tumour microenvironment.
We show for the first time the necessity of iterative sorting to isolate pure marker-positive and marker-negative populations for comparative studies, and present evidence that despite CD133+ and CD133- cells being equally tumourigenic, they display distinct phenotypic differences, suggesting CD133 may define a distinct lineage in melanoma.
转移性黑色素瘤的异质性和致瘤性归因于癌症干细胞模型，CD133被认为是黑色素瘤以及其他肿瘤中的癌症干细胞标志物，但其作用仍存在争议。
我们从3种转移性黑色素瘤细胞系中反复分选CD133+和CD133-细胞，并在NOD/SCID小鼠中观察了7代连续异种移植过程中的致瘤性和表型特征。
我们证明，需要反复分选才能从转移性黑色素瘤中获得高度纯化的CD133+和CD133-细胞群体，并且这两个群体具有与癌症干细胞表型无关的不同特征。在体外，基因集富集分析表明CD133+细胞与增殖表型相关，而CD133-细胞具有侵袭表型。然而，在体内，CD133+和CD133-肿瘤的7代连续移植表明，这两个群体启动和传播肿瘤的能力相同。尽管如此，这两个群体在表型上仍然不同，CD133-细胞仅能在体内而非体外表达CD133。在体外和体内均观察到CD133+细胞表面CD133的丢失，然而，源自CD133+的CD133-细胞即使在存在肿瘤微环境信号的情况下仍保留CD133+表型。
我们首次表明，为进行比较研究，反复分选以分离纯的标志物阳性和标志物阴性群体是必要的，并提供证据表明，尽管CD133+和CD133-细胞具有同等的致瘤性，但它们表现出明显的表型差异，这表明CD133可能在黑色素瘤中定义了一个独特的细胞谱系。
