The Study On Function And Mechanism Of MiR-525-3p In The Migration And Invasion Of Hepatocellular Carcinoma

MicroRNAs (miRNAs) are a class of 21-25 nucleotides, single-stranded non-coding RNAs, which are highly conserved in eukaryotes. miRNA genes are encoded by genome DNA and can regulate gene expression at the post-transcriptional level through degradation or translational repression of their target messenger RNAs (mRNAs). Recent findings suggested that miRNAs play critical roles in development and progression of human malignancies, which can be used as novel molecular targets with a wide range of applications in the diagnosis and treatment of human cancer.Our laboratory previously used wound healing experiment with Live Cell Imaging System to identify the miRNAs that increase or decrease the migratory ability of hepatocellular carcinoma (HCC) cells. After validation by Transwell experiments, we found that 11 miRNAs could regulate HCC cell migration. By combining Pubmed database search with our previous whole-genome copy number variation data of HCC, we selected miR-525-3p as a good candidate for further study.We first determined the expression level of miR-525-3p in HCC, and the results demonstrated that miR-525-3p is frequently up-regulated in HCC tissues. Furthermore, transwell assays showed that the enhanced expression of miR-525-3p can promote HCC cell migration and invasion in vitro. By integrating bioinformatics analysis with real time PCR, luciferase reporter assays, western blot analyses, we identfied that Zinc finger protein 395 (ZNF395) is a direct target for miR-525-3p which can bind its 3’untranslated reagion (3’UTR) in HCC cells.Additionally, we analyzed the expression levels of ZNF395 in HCC by quantitative reverse transcription PCR. The results showed that ZNF395 was frequently downregulated in HCC tissues. Moreover, high expression of ZNF395 can significantly inhibit, whereas knockdown of ZNF395 expression can markedly enhance HCC cell migration and invasion, suggesting that ZNF395 functions as a metastasis suppressor in HCC. Furthermore, we demonstrated that downregulation of ZNF395 can mediate miR-525-3p induced HCC cell migration and invasion.In conclusion, our results demonstrated that miR-525-3p is frequently up-regulated in HCC tissues, and significantly promoted HCC cell migration and invasion. Moreover, the mRNA levels of ZNF395 dramatically decrease in HCC. Furthermore, the ZNF395 can suppress HCC cell migration and invasion, and could be posttranscriptionally regulated by miR-525-3p. These findings provide a novel potential therapeutic target for HCC metastasis.