Increase in Cisplatin Resistance by MeCP2 in Human Gastric Cancer through the Activation of the AKT Pathway by Facilitating PDK-1 Transcription
Increase in Cisplatin Resistance by MeCP2 in Human Gastric Cancer through the Activation of the AKT Pathway by Facilitating PDK-1 Transcription
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DOI：
10.2174/1568009622666220223115216
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发表时间：
2022-01-01
影响因子：
3
通讯作者：
Zhao, Lingyu
中科院分区：
文献类型：
--
作者：
Guo, Bo;Cai, Shuang;Zhao, Lingyu
背景：越来越多的证据表明癌基因失衡与癌症化疗耐药有关。甲基- cpg结合蛋白2 （MeCP2）是多种基因表达的主要表观遗传调控因子，参与胃癌的发生发展。然而，MeCP2在胃癌获得性顺铂耐药中是否起重要作用尚不清楚。目的：研究抑制MeCP2表达是否能使DDP耐药GC细胞对DDP敏感，并阐明其分子机制。方法：采用qRT-PCR和western blotting检测耐药胃癌细胞中MeCP2的表达。随后，通过细胞活力、集落形成、细胞周期、细胞凋亡和致瘤性等实验，探讨MeCP2在体外和体内的作用。采用染色质免疫沉淀- qpcr和荧光素酶报告基因法检测3-磷酸肌醇依赖性蛋白激酶1 （PDK-1）是否为MeCP2的直接靶基因。结果：与非ddp耐药胃癌细胞或正常胃上皮细胞相比，MeCP2在恶性ddp耐药细胞中表达上调。MeCP2敲低增加了DDP耐药GC细胞对DDP的敏感性，导致细胞生长减少，G0/G1期停滞，凋亡增加，而MeCP2过表达减弱了DDP耐药GC细胞对DDP的敏感性。此外，MeCP2敲低可增强DDP在体内的敏感性。MeCP2通过结合启动子区域的CpG位点提高PDK-1的表达，抑制PDK-1逆转了MeCP2过表达对GC细胞DDP抗性的诱导作用。结论：这些发现表明沉默MeCP2可能会增强ddp诱导的细胞死亡，从而为胃癌提供了一种有希望的治疗策略。
Background: Increasing evidence indicates that an imbalance in oncogenes is implicated in cancer chemotherapy resistance. Methyl-CpG binding protein 2 ( MeCP2), which acts as a major epigenetic regulator of the expression of various genes, is involved in the carcinogenesis and progression of gastric cancer. However, is it not known whether the role of MeCP2 is vital in acquired cisplatin resistance in gastric cancer.Objective: This study aimed to determine whether inhibition of MeCP2 expression could sensitize DDP-resistant GC cells to DDP and elucidate the underlying molecular mechanism.Methods: qRT-PCR and western blotting were used to evaluate MeCP2 expression in DDP-resistant GC cells. Subsequently, cell viability, colony formation, cell cycle, apoptosis, and tumorigenicity assays were performed to explore the in vitro and in vivo roles of MeCP2. Chromatin immunoprecipitation-qPCR and luciferase reporter assays were used to identify whether 3-phosphoinositide-dependent protein kinase 1 ( PDK-1) was a direct target gene of MeCP2.Results: MeCP2 was upregulated in malignant DDP-resistant cells compared to non-DDP-resistant GC cells or normal gastric epithelial cells. MeCP2 knockdown increased the sensitivity of DDP- resistant GC cells to DDP, resulting in reduced cell growth, G0/G1 phase arrest, and increased apoptosis, whereas MeCP2 overexpression attenuated DDP sensitivity of DDP-resistant GC cells. In addition, MeCP2 knockdown enhanced DDP sensitivity in vivo. MeCP2 elevated PDK-1 expression by binding to CpG sites in promoter regions, and inhibition of PDK- 1 reversed the inductive effect of MeCP2 overexpression on DDP resistance in GC cells.Conclusion: These findings indicate that silencing of MeCP2 may potentiate DDP-induced cell death, thereby providing a promising therapeutic strategy for GC.