MicroRNA-490-5p Inhibits Migration And Invasion Of Intrahepatic Cholangiocarcinoma Cell RBE And Its Mechanism Study

Background: Intrahepatic cholangiocarcinoma,which is the second most common primary liver cancer in human,shows an up-rising incidence year by year.For now,the hot issues in ICC research field focus on the underlying mechanisms of the genesis and development of ICC.MicroRNA(miRNA)is one kind of small non-coding RNA which normally contains 18~25 nucleotides.It has been widely reported that miRNA played an important role in the regulation of migration,invasion,proliferation as well as differentiation in various carcinomas,but as for its role in ICC,there are still large blank areas.Based on the miRNA microarray data,we picked out miR-490-5p which was found significantly down regulated in biliary tract carcinoma and investigate its role and potential mechanism in the genesis and development of ICC.Methods: 5 pairs intrahepatic cholangiocarcinoma(ICC)samples were put into test by qPCR to investigate the expression level of miR-490-5p.Then,a ICC cell line,RBE was transfected with miR-490-5p mimics as well as Scramble-miRNA mimics,and was further put into the following assays including colony formation,CCK-8,cell wound healing,apoptosis,Transwell and Matrigel Transwell to explore the effects of miR-490-5p over-expression on cell biological processes.The targets of miR-490-5p were predicted by online miRNA target prediction software and validated by Luciferase assay combined with Western Blot.Results: A significant down-regulated trend of the expression of miR-490-5p(P<0.05)was observed in human intrahepatic cholangiocarcinoma samples comparing to para-tumor tissue.By contrast with NC group,over-expression of miR-490-5p in RBE could significantly deter cells from migrating into low chamber in Transwell(P<0.0001)as well as in Matrigel Transwell(P<0.05),and impair cell wound healing rate(P<0.05),but have no impact on the outcomes of CCK-8,colony formation and apoptosis assay(All outcomes with P>0.05).Luciferase assay verified that both predicted binding sites of c-Fos 3’UTR while any one of the three predicted binding sites of ETS1 3’UTR bound by miR-490-5p could lead to a signicicant decrease of fluorescent intensity.Both of c-Fos and Ets1 protein level could be greatly knocked down by overexpression of miR-490-5p.Conclusion: The expression level of miR-490-5p decreased in human intrahepatic cholangiocarcinoma and miR-490-5p could inhibit the migration and invasion ability of RBE,but has on impact on RBE cell proliferation,colony formation and apoptosis.c-Fos and ETS1 are the targets of miR-490-5p.