Eur J Cancer 2011 Nov;47 (17): 2552-9. [IF:4.944]
miR-429 Modulates the expression of c-myc in human gastric carcinoma cells.
Sun T , Wang C , Xing J , Wu D .
Department of General Surgery, Second Affiliated Hospital of Harbin Medical University, Hei LongJiang, Harbin 150081, China.
中国哈尔滨医科大学附属第二医院
Abstract
MicroRNAs (miRNAs) are a recently discovered class of small non-coding RNAs that regulate gene expression and may contribute to the development and progression of many cancers. In this study, our goal was to investigate the regulation of miR-429 in gastric cancer and explored the mechanism/s by which it influenced pathogenesis of gastric cancer. We used real-time reverse transcriptase-polymerase chain reaction to quantify the expression level of miR-429 in 52 gastric cancer tissues and their paracancerous tissues. Bioinformatics was used to predict downstream target genes of miR-429. SGC-7901 gastric cancer cells were transfected with miR-429 mimics and endogenous c-myc expression was detected by western blots. We performed functional assays using the 3'UTR of the c-myc gene as a miR-429 target in a luciferase reporter assay system. We showed that miR-429 was downregulated in human gastric carcinoma tissue and in SGC-7901 cells. Cell viability, proliferation and attachment were inhibited in miR-429-transfected cells. miR-429 significantly downregulated endogenous c-myc expression in SGC-7901 cells. Action of miR/429 on c-myc 3'UTR was confirmed. The levels of miR-429 in tumour tissue of patients with lymph node metastasis were significantly lower than in those without lymph node metastasis. Our results suggested that miR-429 played a role in the pathogenesis of gastric carcinoma and may function as a recessive cancer gene. c-myc is an important miR-429 target gene.
摘要：
微小RNA(miRNAs)是最近发现的一类非编码小RNA，可以调节基因表达，并与许多癌症的发生和发展有关。在此项研究中，我们的目的是研究胃癌中miR-429的调节，并探索其以何种机制影响胃癌发病。我们用实时RT-PCR定量检测miR-429在52例胃癌组织和癌周组织中的表达水平。应用生物信息学预测miR-429的下游靶基因。利用miR-429 mimics转染SGC-7901胃癌细胞，且通过western blots检测出了内源性c-myc的表达。我们在荧光素酶检测系统中利用c-myc基因的3'UTR作为miR-429的靶点，进行了功能性检测。发现miR-429在胃癌组织和SGC-7901细胞中的表达下调。miR-429转染细胞的生存能力、增生和粘附都受到抑制。MiR-429 使c-myc基因在SGC-7901细胞中的表达显著下调。MiR-429对c-myc 3'UTR的作用得到确认。淋巴转移患者肿瘤组织中的miR-429水平显著低于非淋巴转移肿瘤患者。我们的结果提示miR-429与胃癌的发病有关，并且可能起到隐性癌基因的作用。c-myc是miR-429的重要靶基因。
