背景:胃癌(GC)在晚期诊断时预后不佳。本研究的目的是检测肌球蛋白重链11(MYH11)在GC中的表达及其相关机制。
方法:通过SangerBox平台研究GC中的MYH11表达。通过免疫组织化学检查GC组织和细胞系中MYH11的表达,RT-qPCR,和westernblot.分析MYH11表达与患者预后的关系。通过功能获得实验研究了MYH11对GC细胞生物学行为的影响。生物信息学分析用于寻找与GC中MYH11表达相关的基因。通过荧光素酶和ChIP-qPCR分析验证了这种关系,其次是救援试验验证。通过定量甲基化特异性PCR验证了GC中MYH11下调的原因。最后,检查了MYH11对肿瘤生长的影响。
结果:MYH11在GC中下调,预测预后不良。MYH11逆转了GC细胞的恶性表型。MYH11通过与TNFRSF14启动子结合抑制TNFRSF14表达。TNFRSF14逆转MYH11对GC细胞恶性表型的抑制作用。MYH11启动子的甲基化在GC中升高,这与GC中DNMT3B的升高有关。DNMT3B的过表达通过促进MYH11的甲基化来抑制其转录。此外,MYH11上调抑制肿瘤生长。
结论:DNMT3B通过促进MYH11的DNA甲基化抑制其表达,从而减弱MYH11对TNFRSF14转录的抑制作用并促进GC的进展。
BACKGROUND: Gastric cancer (GC) has an unwelcoming prognosis when diagnosed at an advanced stage. The purpose of this study was to examine the expression of myosin heavy chain 11 (MYH11) in GC and mechanisms related.
METHODS: The MYH11 expression in GC was investigated via the SangerBox platform. MYH11 expression in GC tissues and cell lines was examined by immunohistochemistry, RT-qPCR, and western blot. The relationship between
MYH11 expression and patients\' prognosis was analyzed. The effects of MYH11 on the biological behaviors of GC cells were investigated by gain-of-function experiments. Bioinformatics analysis was used to find genes with relevance to MYH11 expression in GC. The relationship was verified by luciferase and ChIP-qPCR assays, followed by rescue assay validation. The causes of MYH11 downregulation in GC were verified by quantitative methylation-specific PCR. Finally, the effect of
MYH11 on tumor growth was examined.
RESULTS: MYH11 was downregulated in GC and predicted poor prognoses.
MYH11 reverted the malignant phenotype of GC cells.
MYH11 repressed the TNFRSF14 expression by binding to the TNFRSF14 promoter. TNFRSF14 reversed the inhibitory effect of MYH11 on the malignant phenotype of GC cells. The methylation of the MYH11 promoter was elevated in GC, which was correlated with the elevated DNMT3B in GC. Overexpression of DNMT3B repressed transcription of MYH11 by promoting its methylation. Also,
MYH11 upregulation inhibited tumor growth.
CONCLUSIONS: DNMT3B inhibits MYH11 expression by promoting its DNA methylation, thereby attenuating the repressive effect of MYH11 on the transcriptional of TNFRSF14 and promoting the progression of GC.