Dpto. Bioquímica. Fac. Medicina. UAM, Madrid, Spain.
Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain.
Theranostics. 2020 Jul 25;10(21):9601-9618. doi: 10.7150/thno.49270. eCollection 2020.
Gastric cancer (GC) is a solid tumor that contains subpopulations of cancer cells (CSCs), which are considered drivers of tumor initiation and metastasis; responsible for therapeutic resistance; and promoters of tumor relapse. The balance between symmetric and asymmetric division is crucial for cell maintenance. The objective of this study is to evaluate the role of MAD2, a key protein for proper mitotic checkpoint activity, in the tumorigenesis of GC. Gastric cancer cells (GCSCs) were obtained from MKN45, SNU638 and ST2957 cell lines. Pluripotency and markers were evaluated by RT-qPCR and autofluorescence and membrane markers by flow cytometry. Relevant signal transduction pathways were studied by WB. We analysed cell cycle progression, migration and invasion after modulation of MAD2 activity or protein expression levels in these models. assays were performed in a nude mouse subcutaneous xenograft model. We found that , CXCR4 and autofluorescence are common and consistent markers for the GCSCs analysed, with other markers showing more variability. The three main signalling pathways (Wnt/β-catenin; Hedgehog and Notch) were activated in GCSCs. Downregulation of MAD2 in MKN45 decreased the expression of markers CXCR4, CD133, CD90, and , without affecting cell cycle profile or therapy resistance. Moreover, migration, invasion and tumor growth were clearly reduced, and accordingly, we found that metalloprotease expression decreased. These results were accompanied by a reduction in the levels of transcription factors related with epithelial-to-mesenchymal transition. We can conclude that MAD2 is important for GCSCs and its downregulation in MKN45 plays a central role in GC tumorigenesis, likely through CXCR4--MMP1. Thus, its potential use in the clinical setting should be studied as its functions appear to extend beyond mitosis.
胃癌（GC）是一种实体肿瘤，包含癌症干细胞（CSC）亚群，这些细胞被认为是肿瘤起始和转移的驱动因素；对治疗耐药性负责；并促进肿瘤复发。对称和不对称分裂之间的平衡对于细胞维持至关重要。本研究的目的是评估 MAD2（一种对于有丝分裂检查点活性至关重要的关键蛋白）在 GC 肿瘤发生中的作用。 从 MKN45、SNU638 和 ST2957 细胞系中获得胃癌细胞（GCSC）。通过 RT-qPCR 和自发荧光以及流式细胞术的膜标志物评估多能性和标志物。通过 WB 研究相关信号转导途径。我们分析了这些模型中 MAD2 活性或蛋白表达水平调节后细胞周期进程、迁移和侵袭。 在裸鼠皮下异种移植模型中进行了 。 我们发现，CXCR4 和自发荧光是分析的 GCSC 的常见且一致的标志物，而其他标志物的变异性更大。三条主要信号通路（Wnt/β-catenin；Hedgehog 和 Notch）在 GCSC 中被激活。MKN45 中 MAD2 的下调降低了 CXCR4、CD133、CD90 和标志物的表达，而不影响细胞周期特征或治疗耐药性。此外，迁移、侵袭和肿瘤生长明显减少，相应地，我们发现金属蛋白酶表达减少。这些结果伴随着与上皮间质转化相关的转录因子水平降低。 我们可以得出结论，MAD2 对 GCSC 很重要，其在 MKN45 中的下调在 GC 肿瘤发生中起核心作用，可能通过 CXCR4-MMP1 起作用。因此，应研究其在临床环境中的潜在用途，因为其功能似乎超出了有丝分裂。
