PVT1 Regulates The Biological Behaviors Of Human Glioma Cells By Targeting MiR-190a-5p And MiR-488-3p

Objective: Glioma is the most common primary tumor in central nervous system with poor outcome,of which the pathogenesis remains unclarified.In the gradually rising number of studies,long non-coding RNAs(lnc RNAs)is becoming a focus in cancers.Lnc RNA-PVT1(also known as Pvt1 oncogene)is associated with various cancers in human,such as Hodgkin lymphoma,gastric cancer,colorectal cancer,non-small cell lung cancer,pancreatic cancer,breast and ovarian cancer,as well as hepatocellular cancer.Mi R-190 is involved in bladder carcinoma,hepatocellular carcinoma,breast cancer,lung cancer.Mi R-488 is down-regulated in prostate carcinoma and gastric cancers.Whereas,the underlying mechanisms of mi R-190a-5p and mi R-488-3p in the malignant behaviors of glioma is unclarified.Myocyte enhancer factor 2C(MEF2C)belongs to the transcription factors family of MADS box transcription enhancer factor 2(MEF2).In recent research MEF2 C is recognized to be an oncogene candidate,which is involved in various tumors,such as hepatocellular carcinoma,rhabdomyosarcoma and leukemia.JAGGED1,a ligand of Notch1,was an oncogene in glioma in previous study.Therefore,the objective in this study is to investigate the differential expression of PVT1,mi R-190a-5p,mi R-488-3p and MEF2 C in glioma,as well as the interactions among these factors and the underlying mechanisms.Methods: 1.Real-time PCR to test the endogenous expression of PVT1,mi R-190a-5p,mi R-488-3p and MEF2 C in glioma tissues and cells.2.Luciferase reporter assay.3.Cell culture of U87,U251,NHA and HEK293 cells.U87,U251 cells were transfected with plasmids to silence PVT1 and MEF2 C,overexpression MEF2 C,up-regulation and down-regulation mi R-190a-5p or mi R-488-3p.4.CCK-8 assay to test the proliferation.5.Cell miagration and invasion assay.6.Flow cytometry to test apoptosis.7.Western Blot.8.CHIP assay.9.Tumor xenografts in nude mice.Results: 1.Up-regulated expression of PVT1 in glioma tissues and cell lines.Knockdown of PVT1 inhibited the proliferation,invasion or migration of glioma cells,and promoted the apoptosis.2.PVT1 was a target of mi R-190a-5p and mi R-488-3p.Konckdown of PVT1 upregulated the expression of mi R-190a-5p and mi R-488-3p.3.Mi R-190a-5p and mi R-488-3p were down-regulated in glioma tissues and cells.Overexpression of mi R-190a-5p or mi R-488-3p inhibited the proliferation,invasion or migration of glioma cells,and promoted the apoptosis.4.Compared with konckdown of PVT1 group,konckdown of PVT1 combined with mi R-190a-5p or mi R-488-3p groups significantly inhibited the proliferation,invasion or migration of glioma cells,and promoted the apoptosis.5.Mi R-190a-5p and mi R-488-3p could respectively bind to the 3’UTR of MEF2 C and inhibit the expression of MEF2 C.6.MEF2 C was upregulated in glioma tisssues and cell lines.Knockdown of MEF2 C could inhibit the proliferation,invasion or migration of glioma cells,and promote the apoptosis.7.MEF2 C could promote the expression of JAGGED1 by binding the promotor region of JAGGED1.8.Up-regulation of mi R-190a-5p or mi R-488-3p combined with upregulation of MEF2 C could reverse the inhibition of the malignant behavior and the expression of JAGGED1 induced by mi R-190a-5p or mi R-488-3p.9.Knockdown of PVT1 combined with mi R-190a-5p and mi R-488-3p overexpression suppressed tumor growth and prolonged the survival of nude mice.Conclusion: 1.PVT1 and MEF2 C was up-regulated in glioma tissues and cell lines,while mi R-190a-5p and mi R-488-3p were down-regulated.2.Knockdown of PVT1 inhibited the malignant behaviors of glioma via up-regulating mi R-190a-5p and mi R-488-3p.3.PVT1 inhibited the expression of mi R-190a-5p and mi R-488-3p,while mi R-190a-5p or mi R-488-3p could negatively regulate MEF2 C by binding to mi R-190a-5p and mi R-488-3p.4.JAGGED1 was a target gene of MEF2 C.Konckdown of MEF2 C could inhibit the proliferation,migration or invasion and the expression of JAGGED1,as well as promote the apoptosis.5.Knockdown of PVT1 combined with overexpression of mi R-190a-5p and mi R-488-3p induced the significant inhibition of tumor growth and prolonged the survival of nude mice.Therefore,PVT1-mi R-190a-5p/mi R-488-3p-MEF2C-JAGGED1 pathway was involved in the regulation of the behaviors of glioma.