miR-203a-5p靶向调控JAG1对多发性骨髓瘤细胞增殖、周期调控的作用及机制研究

MiR-203a-5p Inhibits Multiple Myeloma Cell Proliferation and Cell Cycle Progression via Targeting JAG1

目的:探讨miR-203a-5p在多发性骨髓瘤(MM)中的生物学功能及其调控机制。方法:采用稳健排序整合方法对GEO数据库中的3个miRNA表达谱(GSE16558、GSE24371和GSE17498,包含131个MM样本和17个正常浆细胞样本)进行差异性表达整合分析。用慢病毒构建了能稳定过表达miR-203a-5p的MM细胞株。采用qRT-PCR方法检测MM细胞株RPMI8226及U266中miR-203a-5p的表达情况,并检测miR-203a-5p表达上调后对MM细胞增殖及细胞周期表型的影响。应用稳定表达miR-203a-5p的U226细胞进行裸鼠成瘤实验,评价miR-203a-5p在体内肿瘤发生中的作用。利用Target Scan和miRanda等生物预测软件预测miR-203a-5p的候选靶基因,利用荧光素酶报告基因实验、qRT-PCR和Western blot研究MM细胞中miR-203a-5p的潜在靶点。结果:miR-203a-5p在MM细胞系中的表达显著低于正常浆细胞。miR-203a-5p过表达可以抑制RPMI8226和U266细胞的增殖和细胞周期进展。动物体内实验表明,上调miR-203a-5p可以明显抑制体内肿瘤的生长。通过双荧光素酶报告基因实验证实了JAG1的3’UTR区域可以与miR-203a-5p结合,JAG1是miR-203a-5p的作用靶基因。此外,回复实验结果显示,过表达JAG1可以逆转由miR-203a-5p引起的细胞增殖抑制及周期阻滞。结论:miR-203a-5p通过靶向调控JAG1抑制多发性骨髓瘤细胞的增殖和细胞周期进展,从而发挥抑癌作用,该分子有望作为一种基于miRNA的MM治疗靶点。

Objective: To investigate the biological function of miR-203a-5p and the underlying mechanism in multiple myeloma(MM). Methods: Three miRNA expression profiles(GSE16558, GSE24371 and GSE17498) were downloaded from the GEO database. The three miRNA expression profiles contained 131 MM samples and 17 normal plasmacyte samples. The robust rank aggregation(RRA) method was used to identify the differentially expressed miRNAs between MM and normal plasmacytes. In order to carry out cytological experiments, MM cell line with stable over-expression of miR-203a-5p was constructed with lentivirus. Expression levels of miR-203a-5p in MM cells were quantified by qRT-PCR. The effects of miR-203a-5p on MM cells were investigated using assays of cell viability and cell cycle. Cell proliferation was measured using the Cell Counting kit(CCK)8 assay. The percentage of cells in each cell cycle was measured with a FACSCalibur system. Xenograft tumor models were established to evaluate the role of miR-203a-5p in tumorigenesis in vivo. To elucidate the underlying molecular mechanisms of miR-203a-5p in mediating cell proliferation inhibition and cell cycle arrest in MM, we used TargetScan and miRanda to predict the candidate targets of miR-203a-5p. The potential target of miR-203a-5p in MM cells was explored using the luciferase reporter assay, qRT-PCR, and Western blot. Results: An integrated analysis of three MM miRNA expression datasets showed that the levels of miR-203a-5p in MM were notably downregulated compared with those in normal plasmacytes. Accordingly, the relative expression levels of miR-203a-5p were decreased in MM cell lines. In addition, overexpression of miR-203a-5p inhibited the proliferation and cell cycle progression of RPMI8226 and U266 cells. In vivo experiments demonstrated that upregulation of miR-203a-5p expression could significantly inhibit the tumorigenesis of subcutaneous myeloma xenografts in nude mice. Mechanistic investigation led to the identification of Jagged 1(JAG1) as a novel and direct downstream target of miR-203a-5p. Interestingly, the reintroduction of JAG1 abrogated miR-203a-5p-induced MM cell growth inhibition and cell cycle arrest. Conclusion: Our data demonstrate that miR-203a-5p inhibits cell proliferation and cell cycle progression in MM cells by targeting JAG1, supporting the utility of miR-203a-5p as a novel and potential therapeutic agent for miRNA-based MM therapy.