Gao Zhikui, Zhang Peng, Xie Ming, Gao Han, Yin Lihong, Liu Ran
1Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009 China.
Huzhou Center for Disease Control and Prevention, Huzhou, 313000 China.
Cancer Cell Int. 2018 Nov 15;18:184. doi: 10.1186/s12935-018-0679-8. eCollection 2018.
miRNA clusters are widely expressed across species, accumulating evidence has illustrated that miRNA cluster functioned more efficiently than single miRNA in cancer oncogenesis. It is likely that miRNA clusters are more stable and reliable than individual miRNA to be biomarkers for diagnosis and therapy. We previously found low expression of miR-144/451 was closely related with the risk for esophageal cancer. Researches on miR-144/451 cluster were mostly focused on individual miRNA but not the whole cluster, the regulatory mechanism of miRNA cluster were largely unknown.
In present study, we firstly analysed biological functions of individual miRNAs of miR-144/451 in ECa9706 transfected with miRNA mimics. We further analysed the biological function of the whole cluster in stable transgenic cell overexpressing miR-144/451. We then performed genome-wide mRNA microarray to detect differentially expressed gene profiles in stable transgenic cells.
Overexpression of miR-144-3p promoted early apoptosis of ECa9706 and inhibited cell migration, cell invasion and cell proliferation. miR-144-5p and miR-451a inhibited cell proliferation, at the same time, miR-451a inhibited cell migration. Overexpression of miR-144/451 leads to the arrest cell cycle from S to G2 and G2 to M,while the invasion ability was obviously inhibited. We further observed c-Myc, p-ERK were downregulated in cells overexpressing miR-144/451, while p53 was up-regulated. The downstream effectors of c-Myc, MMP9 and p-cdc2 were downregulated in miR-144/451 stable transgenic cell. miR-144/451 may or partly inhibited cell cycles and invasion of ECa9706 through inhibiting ERK/c-Myc signaling pathway.
Collectively, we analysed the function of miR-144/451 cluster from individual to overall level. miR-144/451 cluster played proto oncogene role in esophageal cancer by inhibiting cell invasion.
miRNA簇在物种间广泛表达，越来越多的证据表明，miRNA簇在癌症发生过程中的作用比单个miRNA更有效。miRNA簇作为诊断和治疗的生物标志物可能比单个miRNA更稳定、更可靠。我们之前发现miR-144/451低表达与食管癌风险密切相关。对miR-144/451簇的研究大多集中在单个miRNA而非整个簇，miRNA簇的调控机制很大程度上尚不清楚。
在本研究中，我们首先分析了用miRNA模拟物转染的ECa9706中miR-144/451单个miRNA的生物学功能。我们进一步分析了在稳定过表达miR-144/451的转基因细胞中整个簇的生物学功能。然后我们进行全基因组mRNA微阵列检测稳定转基因细胞中差异表达的基因谱。
miR-144-3p的过表达促进了ECa9706的早期凋亡，并抑制了细胞迁移、细胞侵袭和细胞增殖。miR-144-5p和miR-451a抑制细胞增殖，同时，miR-451a抑制细胞迁移。miR-144/451的过表达导致细胞周期从S期阻滞到G2期以及从G2期阻滞到M期，同时侵袭能力明显受到抑制。我们进一步观察到，在过表达miR-144/451的细胞中，c-Myc、p-ERK下调，而p53上调。在miR-144/451稳定转基因细胞中，c-Myc的下游效应分子MMP9和p-cdc2下调。miR-144/451可能通过抑制ERK/c-Myc信号通路部分抑制ECa9706的细胞周期和侵袭。
总体而言，我们从个体到整体水平分析了miR-144/451簇的功能。miR-144/451簇通过抑制细胞侵袭在食管癌中发挥原癌基因作用。
