MiRNA-338Modulates The Expression Of CXCR4in Human Neuroblastoma Cells

Objective Neuroblastoma (NB) is one of the most common forms of cancer in young children. Characterized by clinical behaviors, such as spontaneous regression, maturation or aggressive progression, accounts for much of pediatric cancer deaths. MicroRNAs (miRNAs) are a class of small non-coding RNAs that can regulate gene expression by mRNA degradation or translation repression. Recently, our study showed that miRNA-338has the function as mediators of metastasis in human Neuroblastoma. In this study, our goal was to find out the target gene of miRNA-338. Then we we investigated the variation of the possible target gene in human neuroblastoma cell line SH-SY5Y that was over-expressed of miRNA-338and explored the mechanisms by which it influenced invasion, migration of neuroblastoma.Methods With the help of these three computer-aided algorithms including TargetScan, miRanda and PicTar bioinformatic approaches, we obtained a list of predicted targets that may be potentially involved in NB metastasis. Then aritificial synthesized pre-mir-338was transfected into SH-SY5Y cells by Iipofectamine2000. Then we used real-time RT-PCR to quantify the expression level of miRNA-338in these cells. Expression of target gene at mRNA and protein leves were detected by semi-quantitive RT-PCR and Western blotting.Results With the help of these bioinformatic approaches, we obtained that CXCR4(C-X-C chemoking receptor type-4) might be the predicted target gene of miRNA-338. Compared with control groups, Real-time RT-PCR identified an increased miRNA-338expression in pre-mir-338transfected cells. Expression of miRNA-338in the pre-mir-338transfected groups (10nM/L,30nM/L,50nM/L and100nM/L groups) were respectively1.32,1.62,1.90and1.86. But the untransfected group was only1.00. CXCR4mRNA in transfected cells were significantly decreased(0.75±0.06,0.58±0.08,0.24±0.05VS1.11±0.08, P＜O.05), CXCR4protein were also decreased(0.24+0.06VS0.56±0.08, P＜O.05). Conclusions The synthetical pre-mir-338could be successfully transfected into SH-SY5Y cells and led them to over expression of miRNA-338gene. Our results suggest that miRNA-338as a miRNA with potential tumor migration suppressor activity, acting through inhibiting of CXCR4mRNA, which suggests that miRNA-338replacemental therapy through delivery of pre-mir-338may be treated as a novel therapeutic strategy.