Centre for Biomedical Technologies, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, 60 Musk Avenue, GPO Box 2434, Kelvin Grove, QLD, 4059, Australia.
Translational Research Institute, Woolloongabba, Brisbane, Australia.
J Cancer Res Clin Oncol. 2022 Dec;148(12):3501-3510. doi: 10.1007/s00432-022-04242-4. Epub 2022 Aug 6.
Circulating tumour cells (CTCs) are a rare cell subpopulation regulated by the tumour microenvironment. In hypoxic conditions, CTCs are able to invade the lymphatic and circulatory systems leading to metastasis at distant sites.
To mimic in vivo oxygen variations and effects on CTCs, we have cultured five non-small cell lung cancer (NSCLC) cell lines under normoxic and hypoxic conditions, followed by a pulse of reoxygenation for 4 h.
Proliferation, spheroid-formation and colony formation ability under varying O levels were investigated. Proliferation rate was not altered when cells were cultured in 2D models under hypoxic conditions. However, we observed that hypoxia enhanced in vitro formation of tumour-spheres and accelerated clonogenicity of NSCLC cell lines. In addition, cells exposed to hypoxia and reoxygenation conditions showed altered expression of epithelial-mesenchymal transition (EMT) related genes in NSCLC cell lines both at mRNA (AKT1, CAMK2NH1, DESI1, VIM, MAP1B, EGFR, ZEB1, HIF1α) and protein levels (Vimentin, Pan-cytokeratin).
Our data suggest that when investigating CTCs as a prognostic biomarker in NSCLC, it is also essential to take into consideration EMT status to obtain a comprehensive overview of CTCs in circulation.
循环肿瘤细胞（CTC）是受肿瘤微环境调控的稀有细胞亚群。在缺氧条件下，CTC 能够侵袭淋巴和循环系统，导致远处转移。
为了模拟体内氧气变化及其对 CTC 的影响，我们在常氧和缺氧条件下培养了五种非小细胞肺癌（NSCLC）细胞系，随后进行了 4 小时的再氧合脉冲。
研究了不同 O 水平下细胞的增殖、球体形成和集落形成能力。当细胞在缺氧条件下培养于 2D 模型中时，增殖率没有改变。然而，我们观察到缺氧增强了肿瘤球体的体外形成，并加速了 NSCLC 细胞系的克隆形成能力。此外，暴露于缺氧和再氧合条件下的细胞显示出 NSCLC 细胞系中上皮-间充质转化（EMT）相关基因的表达改变，包括 mRNA（AKT1、CAMK2NH1、DESI1、VIM、MAP1B、EGFR、ZEB1、HIF1α）和蛋白水平（波形蛋白、泛细胞角蛋白）。
我们的数据表明，当将 CTC 作为 NSCLC 的预后生物标志物进行研究时，还必须考虑 EMT 状态，以全面了解循环中的 CTC。
