Epigenetic silencing of microRNA-204 by Helicobacter pylori augments the NF-κB signaling pathway in gastric cancer development and progression.
幽门螺杆菌对 microRNA-204 的表观遗传沉默增强了胃癌发生和发展中 NF-κ b 信号通路。
- 作者列表："Chen P","Guo H","Wu X","Li J","Duan X","Ba Q","Wang H
:Helicobacter pylori infection induces gastric cancer (GC) development through a progressive cascade; however, the roles of the microRNAs that are involved in the cascade and the underlying mechanisms are still unclear. Here, we found that microRNA-204 was suppressed in gastric mucosal cells in response to H.pylori infection and downregulated in GC tissues due to aberrant methylation of the promoter of its host gene, TRPM3. Helicobacter pylori induced a progressive downregulation of microRNA-204 from superficial gastritis to intestinal metaplasia, with an accompanying increment of the methylated levels of CpG sites in the TRPM3 promoter. With the GC cellular models of AGS, MGC-803 or BGC-823, we found that microRNA-204 suppressed the tumor necrosis factor (TNF)-α-induced activation of NF-κB signaling pathways and, in animal models, inhibited tumor growth and metastasis. The conditional supernatant of microRNA-204 overexpression GC cells led to reduced tube formation of human umbilical vein endothelial cells. A target gene for microRNA-204 was BIRC2, and in GC cells, BIRC2 knockdown recapitulated the biological phenotype of microRNA-204 overexpression. BIRC2 overexpression promoted the metastasis of GC cells and rescued the inhibition activities of microRNA-204 on cell migration and the NF-κB signaling pathway. Moreover, lower microRNA-204 and higher BIRC2 expression levels were associated with a poorer prognosis of GC patients. These results demonstrate that epigenetic silencing of microRNA-204 induced by H.pylori infection augments the NF-κB signaling pathway in H.pylori-induced gastritis and GC, potentially providing novel intervention targets for these diseases. MicroRNA-204 was epigenetically down-regulated by H. pylori infection in gastric mucosal cells. It led to enhanced BIRC2 expression level and BIRC2/TNF-a/NF-kB signaling pathway activities, which promoted angiogenesis and metastasis of gastric cancer cells.
幽门螺杆菌感染通过进行性级联反应诱导胃癌 (GC) 发展; 然而，参与级联反应的 microRNAs 的作用和潜在机制仍不清楚。在这里，我们发现 microRNA-204 在胃黏膜细胞中受到 H.pylori 感染的抑制，而在 GC 组织中由于其宿主基因 trpm3 启动子的异常甲基化而下调。幽门螺杆菌诱导从浅表性胃炎到肠化生的 microRNA-204 进行性下调，伴随着 TRPM3 启动子中 CpG 位点甲基化水平的增加。通过 AGS 、 MGC-803 或 BGC-823 的 GC 细胞模型，我们发现 microRNA-204 抑制肿瘤坏死因子 (TNF)-α 诱导的 NF-κ b 信号通路的激活,在动物模型中，抑制肿瘤生长和转移。MicroRNA-204 过表达 GC 细胞的条件上清液导致人脐静脉内皮细胞管形成减少。MicroRNA-204 的靶基因是 BIRC2，在 GC 细胞中，BIRC2 敲除概括了 microRNA-204 过表达的生物学表型。BIRC2 过表达促进了 GC 细胞的转移，挽救了 microRNA-204 对细胞迁移和 NF-κ b 信号通路的抑制作用。此外，较低的 microRNA-204 和较高的 BIRC2 表达水平与 GC 患者较差的预后相关。这些结果表明，幽门螺杆菌感染诱导的 microRNA-204 的表观遗传沉默增强了幽门螺杆菌诱导的胃炎和 GC 中的 NF-κ b 信号通路，可能为这些疾病提供新的干预靶点。幽门螺杆菌 (H. pylori) 感染对胃粘膜细胞 MicroRNA-204 有明显的抑制作用。它导致 BIRC2 表达水平和 BIRC2/TNF-a/NF-kB 信号通路活性增强，促进胃癌细胞的血管生成和转移。
METHODS::Diffuse gastric cancer (DGC) is a lethal malignancy lacking effective systemic therapy. Among the most provocative recent results in DGC has been that the alter of the cellular cytoskeleton and intercellular adhesion. CD2-associated protein (CD2AP) is one of the critical proteins regulating cytoskeleton assembly and intercellular adhesion. However, no study has investigated the expression and biological significance of CD2AP in gastric cancer (GC) to date. Therefore, the aim of our study was to explore if the expression of CD2AP is associated with any clinical features of GC and to elucidate the underlying mechanism. Immunohistochemistry of 620 patient tissue samples indicated that the expression of CD2AP is downregulated in DGC. Moreover, a low CD2AP level was indicative of poor patient prognosis. In vitro, forced expression of CD2AP caused a significant decrease in the migration and invasion of GC cells, whereas depletion of CD2AP had the opposite effect. Immunofluorescence analysis indicated that CD2AP promoted cellular adhesion and influenced cell cytoskeleton assembly via interaction with the F-actin capping protein CAPZA1. Overall, the upregulation of CD2AP could attenuate GC metastasis, suggesting CD2AP as a novel biomarker for the prognosis and treatment of patients with GC.
METHODS::Aim: To identify the methylated-differentially expressed genes (MDEGs) that may serve as diagnostic markers and therapeutic targets in Epstein-Barr virus-associated gastric cancer (EBVaGC) and to explore the methylation-based pathways for elucidating biological mechanisms of EBVaGC. Materials & methods: Gene expression and methylation profiles were downloaded from GEO database. MDEGs were identified by GEO2R. Pathway enrichment analyses were conducted based on DAVID database. Hub genes were identified by Cytoscape, which were further verified by The Cancer Genome Atlas database. Results: A total of 367 hypermethylated, lowly expressed genes were enriched in specific patterns of cell differentiation. 31 hypomethylated, highly expressed genes demonstrated enrichment in regulation of immune system process. After validation using The Cancer Genome Atlas database, seven genes were confirmed to be significantly different hub genes in EBVaGC. Conclusion: EBVaGC-specific MDEGs and pathways can be served as potential biomarkers for precise diagnosis and treatment of EBVaGC and provide novel insights into the mechanisms involved.
METHODS:Gastric adenocarcinoma, like other cancers, is a multifactorial genetic disease, andmetastasis of cancer cells is one of the main features of this illness. The expressionlevels of the CFL1 gene have been modulated in this pathway. Using small interferingRNA (siRNA) in the treatment of gastric cancer is considered a hopeful genetherapeutic approach. The present study reported the level of CFL1 genes betweentumor and margin and healthy tissue of gastric cancer. Also, the features of a cationicnanoparticle with a polymer coating containing polyacrylic acid and polyethylenei-mine that were used in the delivery of CFL1 siRNA, were shown. Then thecytotoxicity, cellular uptake, and gene silencing efficiency of this nanoparticle wereevaluated with CFL1siRNA. Method:In this study, the CFL1 gene expression was measured in 40 gastricadenocarcinoma, marginal and 15 healthy biopsy samples by a real‐time polymerasechain reaction. Physicochemical characteristics, apoptosis, and inhibition of migrationof the delivery of CFL1 siRNA by nanoparticle and lipofectamine were investigated ingastric cancer cells. Result:The CFL1 expression was remarkably increased in gastric cancer tissues incomparison with the marginal samples and normal tissues (p< .05) and the biomarkerindex for CFL1 was obtained as 0.94, then this gene can be probably used as abiomarker for gastric cancer. After treatment of the AGS cell line by CFL1 siRNA, theCFL1 expression level of mRNA and migration in AGS cells were remarkablysuppressed after transfection. Furthermore, the amount of apoptosis increased(p< .05). Conclusion:Our results demonstrated that CFL1 downregulation in AGS cells caninterdict cell migration. Finally, our outcomes propose that CFL1 can function as anoncogenic gene in gastric cancer and would be considered as a potential purpose ofgene therapy for gastric cancer treatment