B7同源物4分子对乳腺癌细胞miRNA表达谱的影响

Effect of B7-homolog 4 on microRNA Expression Profile of Breast Cancer Cells

目的通过解析免疫调控分子B7同源物4(B7-H4)对乳腺癌miRNA表达谱的影响,探讨B7-H4介导肿瘤免疫逃逸和乳腺癌进展的潜在机制.方法采用miRNA测序分析B7-H4敲除或过表达的乳腺癌细胞系,筛选共同的差异miRNA;通过qRT-PCR验证差异miRNA,采用TargetFinder和TargetScan预测差异miRNA的靶基因,同时进行基因本体(GO)和京都基因与基因组百科全书数据库(KEGG)信号通路的富集;采用Kaplan-Meier plotter对关键miRNA及靶基因进行生存分析.结果B7-H4敲除后有415个miRNA发生显著变化,而过表达后有134个差异miRNA,通过叠加筛选到36个共同的差异miRNA,通过qRT-PCR验证筛选获得14个差异miRNA;对其进行下游靶基因预测,得到TP53AIP1、RAD52、CDH7、FOXA1、CDH2和ZEB1等涉及细胞增殖和转移功能的基因;富集分析发现,靶基因主要参与癌症进展相关的MAPK和Ras信号通路等,推测其可能参与乳腺癌的病理进展.结论B7-H4通过参与乳腺癌miRNA的表观调控,影响关键靶基因的表达,介导细胞增殖和转移,影响乳腺癌的进展.

Objective This study aims to illustrate the mechanisms underlying the influence of immunoregulatory molecule B7-homolog 4(B7-H4)on the immune escape and tumor progression through the miRNA expression profiles.Methods miRNA profiling was conducted using breast cancer cells with B7-H4 overexpression or knockout.Overlapping miRNAs were selected and then confirmed by qRT-PCR.We use TargetFinder and TargetScan web tools to identify the downstream target genes.To determine significantly enriched pathways,the target genes were subjected to gene ontology(GO)or Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis.We further used the Kaplan-Meier plotter web tool to assess the impact of key miRNAs and target genes on the survival of breast cancer patients.Results B7-H4 knockout breast cancer cells showed significant alterations in 415 miRNAs,while B7-H4 overexpression resulted in significant alterations in 134 miRNAs.Overlapping analysis identified 36 common miRNAs that exhibited consistent changes between the overexpression and knockout cell models.qRT-PCR analysis revealed 14 miRNAs that were associated with target genes involved in cell growth regulation and tumor metastasis,including TP53 AIP1,RAD52,CDH7,FOXA1,CDH2 and ZEB1.Enrichment analysis showed that the target genes primarily participated in MAPK and Ras signaling pathways,suggesting their potential role in breast cancer progression.Conclusion Dysregulation of B7-H4 may change the expression of genes involved in tumor cell growth and metastasis through miRNA-dependent epigenetic regulation,thus affecting the progression and survival of patients with breast cancer.