Study The Mechanism Of MicroRNA-224Involved In The Regulation Of Cell Migration And Invasion In Human Hepatocellular Carcinoma

Background and Aim: miRNAs are small non-coding RNA molecules which regulatetarget gene expression conversely by combine with3’UTR of target mRNA molecules，involved in the regulation of biological pathway of various diseases. Research shows that,miRNAs mutation or ectopic expression is related with many human tumor. about50%miRNAs in fragile sites associated with tumors in the human genome, suggesting thatmiRNAs plays a critical role in tumorigenesis, and have similar tumor suppressor gene(tumor suppressor miRNAs, TS-miRs) or cancer gene (oncogenic miRNAs, oncomiRs)function.The occurrence and development of the hepatocellular carcinoma (HCC) is a gradualprocess with multi gene, multi-step and multi channel change.its feature is high degree ofmalignancy, invasion and metastasis and bad prognosis. the cancer cell invasion andmetastasis is a big problem for treatment,and also is the key link of its prognosis. It hasbeen proved that multiple miRNAs related to the occurrence and development ofhepatocellular carcinoma.MiR-224as a specific cancer miRNA is widely studied. miRNA-224:one of themembers of the family of small non-coding RNA, resides in chrxq28, GABRE a regionknown to be transcriptionally quiescent.miR-224was reported to be overexpression invarious tumor cells,such as: pancreatic cancer, ovarian cancer, breast cancer and so on. Inour earlier study, we found that miR-224was overexpressed in HCC and participate in theregulation of cell migration, But the specific mechanism is not clear. The aim of this studyis to clarify the target gene that miRNA-224directly regulate and to explore itspossible mechanism involved in the regulation of liver cancer cell migration and invasion. Methods:1. Luciferase-reporter assay、Vector construction and western blot were performed todetermine that the HOXD10gene was a direct target of miR-2242. RNA interference technology、Matrigel invasion assay were performed to confirmethat the HOXD10gene is the key molecule when miR-224regulates hepatocellularcarcinoma cell invasion and metastasis3. the Western blot assay and cell transfection technique demonstrated thatmiR-224/HOXD10/MMP-9/p-PAK4pathway is involved in regulate cells invasion andmigration.Results:1. The expression of miR-224was up-regulated in hepatocellular carcinoma cells, andits expression level was positively associated with cell invasive potential. The highexpression of miR-224promotes tumor cell invasion and migration.2. miR-224directly targets the HOXD10gene3. the HOXD10gene is the key molecule when miR-224regulates hepatocellularcarcinoma cell invasion and metastasis4. miR-224promote expression of the PAK4and MMP-9by directly targetingHOXD10Conclusion: the miR-224/HOXD10/p-PAK4/MMP-9signaling pathway contributes tothe regulation of HCC cell migration and invasion.