Université de Lorraine, Centre de Recherche en Automatique de Nancy, CRAN, UMR 7039, Vandœuvre-lès-Nancy, F-54506, France.
Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, LCPME, UMR 7564, Villers-lès-Nancy, F-54600, France.
Nanoscale. 2016 Mar 7;8(9):5268-79. doi: 10.1039/c5nr09126h.
DDB2, known for its role in DNA repair, was recently shown to reduce mammary tumor invasiveness by inducing the transcription of IκBα, an inhibitor of NF-κB activity. Since cellular adhesion is a key event during the epithelial to mesenchymal transition (EMT) leading to the invasive capacities of breast tumor cells, the aim of this study was to investigate the role of DDB2 in this process. Thus, using low and high DDB2-expressing MDA-MB231 and MCF7 cells, respectively, in which DDB2 expression was modulated experimentally, we showed that DDB2 overexpression was associated with a decrease of adhesion abilities on glass and plastic areas of breast cancer cells. Then, we investigated cell nanomechanical properties by atomic force microscopy (AFM). Our results revealed significant changes in the Young's Modulus value and the adhesion force in MDA-MB231 and MCF7 cells, whether DDB2 was expressed or not. The cell stiffness decrease observed in MDA-MB231 and MCF7 expressing DDB2 was correlated with a loss of the cortical actin-cytoskeleton staining. To understand how DDB2 regulates these processes, an adhesion-related gene PCR-Array was performed. Several adhesion-related genes were differentially expressed according to DDB2 expression, indicating that important changes are occurring at the molecular level. Thus, this work demonstrates that AFM technology is an important tool to follow cellular changes during tumorigenesis. Moreover, our data revealed that DDB2 is involved in early events occurring during metastatic progression of breast cancer cells and will contribute to define this protein as a new marker of metastatic progression in this type of cancer.
DDB2 以其在 DNA 修复中的作用而闻名，最近的研究表明，它通过诱导 NF-κB 活性抑制剂 IκBα 的转录，降低了乳腺肿瘤的侵袭性。由于细胞黏附是上皮间质转化（EMT）过程中的一个关键事件，导致乳腺癌细胞的侵袭能力，本研究的目的是研究 DDB2 在这个过程中的作用。因此，我们使用低表达和高表达 DDB2 的 MDA-MB231 和 MCF7 细胞，分别通过实验调节 DDB2 的表达，结果表明 DDB2 的过表达与乳腺癌细胞在玻璃和塑料表面的黏附能力下降有关。然后，我们通过原子力显微镜（AFM）研究了细胞纳米力学特性。我们的结果表明，无论是否表达 DDB2，MDA-MB231 和 MCF7 细胞的杨氏模量值和黏附力都发生了显著变化。在表达 DDB2 的 MDA-MB231 和 MCF7 细胞中观察到的细胞硬度降低与皮质肌动蛋白细胞骨架染色的丢失有关。为了了解 DDB2 如何调节这些过程，我们进行了一个与黏附相关的基因 PCR 芯片分析。根据 DDB2 的表达，一些与黏附相关的基因差异表达，表明在分子水平上发生了重要的变化。因此，这项工作表明 AFM 技术是一种重要的工具，可以在肿瘤发生过程中跟踪细胞的变化。此外，我们的数据表明，DDB2 参与了乳腺癌细胞转移进展过程中早期发生的事件，并将有助于将该蛋白定义为这种癌症转移进展的新标志物。
