SMARCC2 combined with c‑Myc inhibits the migration and invasion of glioma cells via modulation of the Wnt/β‑catenin signaling pathway.
SMARCC2 combined with c‑Myc inhibits the migration and invasion of glioma cells via modulation of the Wnt/β‑catenin signaling pathway.
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DOI：
10.3892/mmr.2021.12190
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发表时间：
2021-08
影响因子：
3.4
通讯作者：
Zhou Q
中科院分区：
文献类型：
--
作者：
Li C;Fei C;Li J;Wu H;Chen L;Roshani R;Li H;Shi L;Song C;Gu J;Lu Y;Zhou Q
神经胶质瘤是中枢神经系统最常见的肿瘤类型。SWItch/sucrose non-fermentable（SWI/SNF）是一种在上皮-间质转化（EMT）中起重要作用的肿瘤抑制因子。本研究旨在确定参与EMT过程的关键分子。SWI/SNF相关的、基质相关的、染色质亚家族c成员2的肌动蛋白依赖性调节因子（SMARCC 2）在多种类型的癌症中突变并且其表达低。SMARCC 2是染色质重塑复合物SWI/SNF的核心亚基。通过逆转录-定量PCR分析人脑胶质瘤组织中SMARCC 2的相对mRNA表达水平，而通过免疫组织化学染色确定蛋白质表达水平。使用小干扰RNA（si）在胶质瘤细胞中敲低SMARCC 2表达，并通过用携带SMARCC 2 cDNA的腺病毒载体感染来过表达SMARCC 2。分别进行伤口愈合和Transwell测定以评估细胞迁移和侵袭。随后，进行免疫荧光和蛋白质印迹以分析与SMARCC 2相关的癌基因c-Myc的表达水平。SMARCC 2与C-MYC结合以下调其表达。与生物信息学分析的结果一致，其揭示SMARCC 2的上调表达水平与胶质瘤患者的更有利预后相关，与高级别胶质瘤组织相比，SMARCC 2的mRNA和蛋白表达水平在低级别胶质瘤组织中显著上调。伤口愈合测定的结果表明，与阴性对照（NC）组相比，siSMARCC 2 -1/3组中的细胞迁移显著增加。相比之下，与慢病毒载体非特异性对照（LVS-NC）组相比，用过表达SMARCC 2的腺病毒转导后细胞的迁移能力显著降低，所述腺病毒上调SMARCC 2的表达。Transwell实验结果进一步表明，SMARCC 2过表达组U87 MG和LN 229细胞的迁移和侵袭能力明显低于LVS-NC组。随后进行免疫共沉淀试验以验证SMARCC 2和c-Myc的结合;结果表明，与LVS-NC转染的细胞相比，腺病毒转染的细胞中c-Myc的表达下调。Western blotting实验结果显示，与LVS-NC组相比，稳定过表达SMARCC 2的细胞株中N-cadherin、vimentin、snail家族转录抑制因子1和β-catenin的表达水平显著下调，而T-cadherin的表达水平显著上调。本研究结果提示SMARCC 2可能通过调控c-Myc表达抑制Wnt/β-catenin信号通路。SMARCC 2通过介导癌基因C-MYC的表达来抑制胶质母细胞瘤细胞系的迁移和侵袭能力，从而调节胶质母细胞瘤细胞系的EMT状态。因此，SMARCC 2可能通过调节相关的癌基因或肿瘤抑制基因而作为肿瘤抑制基因或癌基因发挥作用。
Glioma is the most common type of central nervous system tumor. SWItch/sucrose non-fermentable (SWI/SNF) is a tumor suppressor that serves an important role in epithelial-mesenchymal transition (EMT). The present study aimed to identify key molecules involved in the EMT process. SWI/SNF related, matrix associated, actin dependent regulator of chromatin subfamily c member 2 (SMARCC2) is mutated in and its expression is low in multiple types of cancer. SMARCC2 is the core subunit of the chromatin-remodeling complex, SWI/SNF. Relative mRNA SMARCC2 expression levels in human glioma tissue were analyzed via reverse transcription-quantitative PCR, whereas the protein expression levels were determined via immunohistochemistry staining. SMARCC2 expression was knocked down in glioma cells using small interfering RNA (si) and overexpressed by infection with adenovirus vectors carrying SMARCC2 cDNA. Wound healing and Transwell assays were performed to assess cell migration and invasion, respectively. Subsequently, immunofluorescence and western blotting were performed to analyze the expression levels of the oncogene c-Myc, which is associated with SMARCC2. SMARCC2 combines with C-MYC to downregulate its expression. Consistent with the results of the bioinformatics analysis, which revealed that the upregulated expression levels of SMARCC2 were associated with a more favorable prognosis in patients with glioma, the mRNA and protein expression levels of SMARCC2 were significantly upregulated in low-grade glioma tissues compared with high-grade glioma tissues. The results of the wound healing assay demonstrated that cell migration was significantly increased in the siSMARCC2-1/3 groups compared with the negative control (NC) group. By contrast, the migratory ability of cells was significantly reduced following transduction with adenovirus overexpressing SMARCC2, which upregulated the expression of SMARCC2, compared with the lentiviral vector-non-specific control (LVS-NC) group. The Transwell assay results further showed that SMARCC2 overexpression significantly inhibited the migratory and invasive abilities of U87MG and LN229 cells compared with the LVS-NC group. Co-immunoprecipitation assays were subsequently conducted to validate the binding of SMARCC2 and c-Myc; the results demonstrated that the expression of c-Myc was downregulated in adenovirus-transfected cells compared with LVS-NC-transfected cells. The results of the western blotting experiments demonstrated that the expression levels of N-cadherin, vimentin, snail family transcriptional repressor 1 and β-catenin were notably downregulated, whereas the expression levels of T-cadherin were markedly upregulated in cell lines stably overexpressing SMARCC2 compared with the LVS-NC group. In conclusion, the results of the present study suggested that SMARCC2 may inhibit Wnt/β-catenin signaling by regulating c-Myc expression in glioma. SMARCC2 regulates the EMT status of the glioblastoma cell line by mediating the expression of the oncogene C-MYC to inhibit its migration and invasion ability. Thus, SMARCC2 may function as a tumor suppressor or oncogene by regulating associated oncogenes or tumor suppressor genes.