Key Laboratory of Animal Resistance Research, College of Life Science, Shandong Normal University, Jinan, Shandong, China.
Department of Clinical Laboratory, Shandong Cancer Hospital and Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China.
Ann Clin Lab Sci. 2021 Jul;51(4):521-528.
Radioresistance-induced locoregional recurrence remains a major cause of low survival rates. However, the mechanism of treatment failure in these lung cancer patients has not been determined. In the current study, we tried to explore the potential molecular mechanism.
The fractionated irradiations were continued until the total concentration reached 80 Gy, and we established radioresistant subclones derived from A549 lines (designated as A549/R). The MTT assay, wound healing assay, transwell assay, and soft agar colony formation assay were employed to detect the proliferation, migration, invasion, and clonogenicity of the cells, respectively. Western blot and Fluorescence Activating Cell Sorter (FACS) indicated the expression of the markers.
A549/R cells proliferated more slowly than the parental A549 cells. A significant acceleration in cell migration and invasion was revealed in A549/R cells compared with A549 cells. The expression levels of mesenchymal markers (N-cadherin, vimentin, claudin-1, and Snail) increased, while epithelial markers (E-cadherin and β-catenin) decreased in A549/R cells. Meanwhile, the expression levels of stemness markers (Oct4, Notch1, and CD133) increased in A549/R cells, and A549/R cells showed more sphere-forming activity compared with A549 cells.
Fractionated irradiation could promote epithelial-mesenchymal transition and enhance the migration, invasion, and stemness-like properties in A549 cells, elucidating the possible radioresistance mechanisms of the cancer cells.
放射抗拒导致的局部区域复发仍然是低生存率的主要原因。然而，这些肺癌患者治疗失败的机制尚未确定。在本研究中，我们试图探讨潜在的分子机制。
继续进行分次照射，直到总浓度达到 80Gy，并从 A549 系中建立放射抗性亚克隆（命名为 A549/R）。MTT 检测、划痕愈合试验、Transwell 检测和软琼脂集落形成试验分别用于检测细胞的增殖、迁移、侵袭和克隆形成能力。Western blot 和 Fluorescence Activating Cell Sorter（FACS）检测标记物的表达。
A549/R 细胞的增殖速度比亲本 A549 细胞慢。与 A549 细胞相比，A549/R 细胞的迁移和侵袭明显加快。与 A549 细胞相比，A549/R 细胞中间充质标志物（N-钙黏蛋白、波形蛋白、claudin-1 和 Snail）的表达水平升高，而上皮标志物（E-钙黏蛋白和β-连环蛋白）的表达水平降低。同时，A549/R 细胞中干性标志物（Oct4、Notch1 和 CD133）的表达水平升高，与 A549 细胞相比，A549/R 细胞具有更多的球体形成活性。
分次照射可促进上皮-间充质转化，并增强 A549 细胞的迁移、侵袭和类干性特性，阐明了癌细胞可能的放射抵抗机制。
