- 作者列表："Song Z","Wei Z","Wang Q","Zhang X","Tao X","Wu N","Liu X","Qian J
BACKGROUND:Disruptor of telomeric silencing-1-like (DOT1L), a methyltransferase of H3K79, was observed to be amplified and overexpressed in certain malignancies. This work was aimed at investigating the differences in DOT1L expression and its regulatory mechanism in gastric cancer (GC) and healthy samples. METHODS:Immunohistochemistry was used to detect DOT1L levels in 101 cases of GC and marching adjacent normal tissues. DOT1L was inhibited by small interfering RNA (siRNA) and EPZ5676; a targeting drug. The ability of cells to proliferate were checked by cell counting kit-8 (CCK-8) and clone formation assays, with flow cytometry for observing the cell cycle. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot revealed the gene and protein profiles. Finally, the outcome of EPZ5676 administration was checked on a murine model. RESULTS:The expression of DOT1L is significantly increased in gastric malignant tumors that is related to the degree of differentiation, lymph node metastasis and TNM staging. DOT1L serves as an independent marker for the prognosis of overall survival (OS) with high levels implying worse prognosis. In addition, DOT1L regulates cyclin-dependent kinase (CDK) 4 (CDK4) and CDK6 through H3K79me2, which leads to a change in the cell cycle at G1, thereby affecting the proliferation of tumors in vitro and in vivo. CONCLUSIONS:This is a first clinical demonstration of the applicability of DOT1L overexpression in gastric tumors. The work is suggestive of altered proliferation of cells by DOT1L via regulating cyclins and H3K79 methylation. This indicates the role of DOT1L in the prognosis and possible medical intervention of GC.
背景: 端粒沉默-1 样 (DOT1L) 的干扰物，H3K79 的甲基转移酶，在某些恶性肿瘤中观察到扩增和过表达。这项工作旨在研究胃癌 (GC) 和健康样本中 DOT1L 表达的差异及其调控机制。 方法: 采用免疫组织化学方法检测 101 例胃癌及癌旁正常组织中 DOT1L 水平。DOT1L 被小干扰 RNA (siRNA) 和靶向药物 EPZ5676 抑制。通过细胞计数试剂盒-8 (CCK-8) 和克隆形成试验检测细胞增殖能力，用流式细胞术观察细胞周期。定量逆转录聚合酶链反应 (qRT-PCR) 和 Western blot 揭示了基因和蛋白谱。最后，在小鼠模型上检查 EPZ5676 给药的结果。 结果: DOT1L 在胃恶性肿瘤中表达明显增高，且与分化程度、淋巴结转移及 TNM 分期有关。DOT1L 作为总生存期 (OS) 预后的独立标志物，高水平提示预后更差。此外，DOT1L 通过 H3K79me2 调控细胞周期蛋白依赖性激酶 (CDK) 4 (CDK4) 和 CDK6，导致细胞周期在 G1, 从而影响肿瘤在体外和体内的增殖。 结论: 这是 DOT1L 过表达在胃肿瘤中适用性的首次临床证明。这项工作提示 DOT1L 通过调节细胞周期蛋白和 H3K79 甲基化改变细胞增殖。这表明 DOT1L 在 GC 的预后和可能的医疗干预中的作用。
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