Martins-Neves Sara R, Corver Willem E, Paiva-Oliveira Daniela I, van den Akker Brendy E W M, Briaire-de-Bruijn Inge H, Bovée Judith V M G, Gomes Célia M F, Cleton-Jansen Anne-Marie
Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands.
Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
J Cell Physiol. 2016 Apr;231(4):876-86. doi: 10.1002/jcp.25179. Epub 2015 Sep 9.
Osteosarcoma is a bone tumor, displaying significant cellular and histological heterogeneity and a complex genetic phenotype. Although multiple studies strongly suggest the presence of cancer stem cells in osteosarcoma, a consensus on their characterization is still missing. We used a combination of functional assays (sphere-forming, Aldefluor, and side-population) for identification of cancer stem cell populations in osteosarcoma cell lines. Expression of stemness-related transcription factors, quiescent nature, in vivo tumorigenicity, and Wnt/β-catenin activation were evaluated. We show that different cancer stem cell populations may co-exist in osteosarcoma cell lines exhibiting distinct functional properties. Osteosarcoma spheres are slowly-proliferating populations, overexpress SOX2, and KLF4 stemness-related genes and have enhanced tumorigenic potential. Additionally, spheres show specific activation of Wnt/β-catenin signaling as evidenced by increased nuclear β-catenin, TCF/LEF activity, and AXIN2 expression, in a subset of the cell lines. Aldefluor-positive populations were detected in all osteosarcoma cell lines and overexpress SOX2, but not KLF4. The side-population phenotype is correlated with ABCG2 drug-efflux transporter expression. Distinct functional methods seem to identify cancer stem cells with dissimilar characteristics. Intrinsic heterogeneity may exist within osteosarcoma cancer stem cells and can have implications on the design of targeted therapies aiming to eradicate these cells within tumors. J. Cell. Physiol. 231: 876-886, 2016. © 2015 Wiley Periodicals, Inc.
骨肉瘤是一种骨肿瘤，具有显著的细胞和组织学异质性以及复杂的基因表型。尽管多项研究强烈提示骨肉瘤中存在癌症干细胞，但对其特征的共识仍未达成。我们使用了功能分析方法（成球、醛脱氢酶和侧群细胞分析）的组合来鉴定骨肉瘤细胞系中的癌症干细胞群体。评估了干性相关转录因子的表达、静止特性、体内致瘤性以及Wnt/β-连环蛋白激活情况。我们发现不同的癌症干细胞群体可能共存于具有不同功能特性的骨肉瘤细胞系中。骨肉瘤球体是增殖缓慢的群体，过表达SOX2和KLF4等干性相关基因，并且具有增强的致瘤潜力。此外，在一部分细胞系中，球体显示出Wnt/β-连环蛋白信号的特异性激活，表现为核β-连环蛋白增加、TCF/LEF活性增强以及AXIN2表达增加。在所有骨肉瘤细胞系中均检测到醛脱氢酶阳性群体，它们过表达SOX2，但不过表达KLF4。侧群细胞表型与ABCG2药物外排转运蛋白的表达相关。不同的功能方法似乎鉴定出了具有不同特征的癌症干细胞。骨肉瘤癌症干细胞内部可能存在内在异质性，这可能对旨在根除肿瘤内这些细胞的靶向治疗设计产生影响。《细胞生理学杂志》2016年第231卷：876 - 886页。© 2015威利期刊公司
