Cellular Reprogramming and Embryo Biotechnology Lab, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
Department of Biomedical Engineering, University of Illinois, Chicago, IL, USA; Jesse Brown Veterans Affairs Medical Center (JBVAMC), Chicago, IL, USA.
Gene. 2022 Jul 1;830:146504. doi: 10.1016/j.gene.2022.146504. Epub 2022 Apr 25.
Lung cancer is the prominent cause of cancer-associated death primarily because of distant metastatic disease. The metastatic potential of non-small cell lung cancer (NSCLC) is associated with tumor cell aggregation. However, the systemic mechanotransduction mechanism by which tumor cells dynamically aggregate and disseminate is poorly understood, especially in NSCLC. In this study, we examine whether the cell surface matrix plays an important role in metastasis. We used poly-2-hydroxyethyl methacrylate-based 3D spheroid formation methods to mimic in vivo metastatic lesions. Supra-structural analysis of human NSCLC A549 cells stained with ruthenium red for transmission electron microscopy (TEM) showed that glycocalyx surrounding the cell surface in 2D culture decreases in 3D culture. Comprehensive gene expression analysis revealed that the genes associated with cell adhesion were distinctly enriched in A549 cell spheroids. Of these, downregulation of the tumor metastatic microenvironment facilitator LOXL2, a copper-dependent enzyme catalyzing posttranslational oxidative deamination of peptidyl lysine, was of special interest. Knockdown of LOXL2 thickened the cell surface matrix in 2D culture and impaired compact aggregate formation in 3D culture. Moreover, A549 cell spheroids with endogenous overexpression of LOXL2 increased their dissemination on basement extracellular matrix Matrigel. Overall, these data imply that cell detachment-downregulated LOXL2 contributes to cell surface matrix remodeling, leading to collective dissemination of free-floating aggregates.
肺癌是癌症相关死亡的主要原因，主要是因为远处转移疾病。非小细胞肺癌（NSCLC）的转移潜力与肿瘤细胞聚集有关。然而，肿瘤细胞动态聚集和扩散的系统力学转导机制还知之甚少，尤其是在 NSCLC 中。在这项研究中，我们研究了细胞表面基质是否在转移中起重要作用。我们使用基于聚-2-羟乙基甲基丙烯酸酯的 3D 球体形成方法来模拟体内转移病变。用钌红对人 NSCLC A549 细胞进行超结构分析，用于透射电子显微镜（TEM）染色，结果表明，在 2D 培养中，细胞表面周围的糖萼在 3D 培养中减少。全面的基因表达分析显示，与细胞黏附相关的基因在 A549 细胞球体中明显富集。其中，肿瘤转移微环境促进因子 LOXL2 的下调特别引起关注，LOXL2 是一种铜依赖性酶，催化肽基赖氨酸的翻译后氧化脱氨。LOXL2 的敲低会在 2D 培养中增加细胞表面基质的厚度，并在 3D 培养中损害紧密聚集的形成。此外，内源性过表达 LOXL2 的 A549 细胞球体增加了它们在基底膜外基质 Matrigel 上的扩散。总的来说，这些数据表明，细胞脱落后下调的 LOXL2 有助于细胞表面基质重塑，导致游离聚集体的集体扩散。
