Population and Quantitative Genetics Laboratory, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.
School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
Clin Cancer Res. 2018 Apr 1;24(7):1748-1760. doi: 10.1158/1078-0432.CCR-17-1169. Epub 2017 Sep 28.
Lung cancer is the leading cause of cancer-related death in the world, and emerging evidences suggest that lung cancer stem cells (CSC) are associated with its poor prognosis, tumor recurrence, and therapy resistance. Here we reveal a novel role for miR-708-5p in inhibiting lung CSC-like features. Phenotypic effects of miR-708-5p on the lung CSC-like properties were examined by sphere formation assay and in xenografted animal models. Immunoblotting, dual luciferase reporter, and immunocytochemistry were performed to determine the target of miR-708-5p. DNA methylation of CDH1 promoter region was tested using bisulfate sequencing. Genome-wide miRNA sequencing data of 990 patients from The Cancer Genome Atlas (TCGA) dataset and 148 patients from China cohort were analyzed to excavate the pathogenic implications of miR-708-5p. Expression of miR-708-5p inhibits the CSC traits of NSCLC cells while antagonizing miR-708-5p promotes tumorigenesis miR-708-5p directly suppresses the translation of DNMT3A, which results in a substantial reduction of global DNA methylation and the upregulated expression of tumor suppressor CDH1. The upregulation of CDH1 decreased the activity of Wnt/β-catenin signaling and then impaired the stemness characteristics of NSCLC cells. Clinically, patients with high miR-708-5p expression show significantly better survival and lower recurrence. Furthermore, miR-708-5p has a promising potential to apply to differentiating histologic subtypes in NSCLC. Our findings support that miR-708-5p suppresses NSCLC initiation, development, and stemness through interfering DNMT3A-dependent DNA methylation. miR-708-5p may function as a novel diagnostic and prognostic biomarker in NSCLC. .
肺癌是全球癌症相关死亡的主要原因，有新的证据表明肺癌干细胞（CSC）与预后不良、肿瘤复发和治疗耐药有关。在这里，我们揭示了 miR-708-5p 在抑制肺癌 CSC 样特征中的新作用。通过球形成试验和异种移植动物模型，检查了 miR-708-5p 对肺癌 CSC 样特性的表型影响。通过免疫印迹、双荧光素酶报告基因和免疫细胞化学测定 miR-708-5p 的靶标。使用亚硫酸氢盐测序测试 CDH1 启动子区域的 DNA 甲基化。分析了来自癌症基因组图谱（TCGA）数据集的 990 名患者和来自中国队列的 148 名患者的全基因组 miRNA 测序数据，以挖掘 miR-708-5p 的致病意义。miR-708-5p 的表达抑制 NSCLC 细胞的 CSC 特性，而拮抗 miR-708-5p 则促进肿瘤发生。miR-708-5p 直接抑制 DNMT3A 的翻译，导致全局 DNA 甲基化大量减少和肿瘤抑制因子 CDH1 的上调表达。CDH1 的上调降低了 Wnt/β-catenin 信号的活性，从而损害了 NSCLC 细胞的干性特征。临床上，miR-708-5p 高表达的患者生存显著改善，复发率降低。此外，miR-708-5p 有望应用于 NSCLC 的组织学亚型区分。我们的研究结果表明，miR-708-5p 通过干扰 DNMT3A 依赖性 DNA 甲基化抑制 NSCLC 的发生、发展和干性。miR-708-5p 可能作为 NSCLC 的一种新的诊断和预后生物标志物。
