Fang Ziling, Zhang Ling, Liao Quan, Wang Yi, Yu Feng, Feng Miao, Xiang Xiaojun, Xiong Jianping
Department of Oncology, the First Affiliated Hospital of Nanchang University, 17 Yongwaizheng Street, Donghu District, Nanchang, 330006, Jiangxi Province, China.
J Exp Clin Cancer Res. 2017 Jan 23;36(1):17. doi: 10.1186/s13046-017-0489-1.
Increasing evidence highlights the important roles of tripartite motif containing 24 (TRIM24) in tumor initiation and malignant progression in many tumors, including gastric cancer (GC). Although TRIM24 expression is remarkably upregulated during GC carcinogenesis, the molecular mechanisms underlying TRIM24 dysregulation remain unexplored.
In this study, miRNA target prediction tools were applied to explore miRNAs that potentially target TRIM24. Western blot and quantitative reverse-transcriptase PCR (qRT-PCR) were performed to detected TRIM24 and miR-511 expression in GC tissues and cell lines. Dual-luciferase reporter assay was utilized to validate if TRIM24 is a direct target gene of miR-511. CCK-8 assay, cell colony formation assay, EdU incorporation assay and cell cycle analysis were performed to determine whether miR-511-mediated regulation of TRIM24 could affect GC progression.
In our study, miR-511 was found to be downregulated in GC and an inverse correlation was observed between TRIM24 and miR-511 expression in primary GC tissues and cell lines. Dual-luciferase reporter assay further verified TRIM24 is a direct target of miR-511. Functional assays showed miR-511 overexpression inhibited cell growth, colony formation ability and cell cycle progression. Conversely, inhibition of endogenous miR-511 promoted these phenotypes in GC cells. Moreover, reintroduction of TRIM24 rescued miR-511-induced inhibitory effects on GC cells. Furthermore, miR-511 elicits tumor-suppressive effects through inactivating PI3K/AKT and Wnt/β-catenin pathways by suppressing TRIM24.
Our results provide the new evidence supporting the tumor-suppressive role of miR-511 in GC by suppressing TRIM24, suggesting that this novel miR-511/TRIM24 axis is critical in the control of gastric cancer tumorigenesis.
越来越多的证据表明，含三联基序蛋白24（TRIM24）在包括胃癌（GC）在内的许多肿瘤的起始和恶性进展中发挥重要作用。尽管在胃癌发生过程中TRIM24表达显著上调，但其失调的分子机制仍未被探索。
在本研究中，应用miRNA靶标预测工具探索可能靶向TRIM24的miRNA。采用蛋白质免疫印迹法和定量逆转录PCR（qRT-PCR）检测GC组织和细胞系中TRIM24和miR-511的表达。利用双荧光素酶报告基因检测验证TRIM24是否为miR-511的直接靶基因。进行CCK-8检测、细胞集落形成检测、EdU掺入检测和细胞周期分析，以确定miR-511介导的TRIM24调控是否会影响GC进展。
在我们的研究中，发现miR-511在GC中表达下调，并且在原发性GC组织和细胞系中观察到TRIM24与miR-511表达呈负相关。双荧光素酶报告基因检测进一步验证了TRIM24是miR-511的直接靶标。功能检测表明，miR-511过表达抑制细胞生长、集落形成能力和细胞周期进程。相反，抑制内源性miR-511可促进GC细胞中的这些表型。此外，重新引入TRIM24可挽救miR-511对GC细胞的抑制作用。此外，miR-511通过抑制TRIM24使PI3K/AKT和Wnt/β-连环蛋白通路失活，从而发挥肿瘤抑制作用。
我们的结果提供了新的证据，支持miR-511通过抑制TRIM24在GC中发挥肿瘤抑制作用，表明这种新的miR-511/TRIM24轴在控制胃癌肿瘤发生中至关重要。
