TRIM22 Promotes Proliferation,Invasion And Migration Of Glioblastoma By Regulating PI3K/AKT Signaling

Research background: Glioblastoma(GBM)is the most common and lethal primary brain tumor in the nervous system of adults.Despite tremendous advances in surgical resection,tensive treatment with combined multiagent radiation and chemotherapy,patients generally show poor prognosis and incurable relapse of the disease.The median survival time of patients with glioblastoma is short,at approximately 14.6 months.Therefore,effective identification and development of novel molecular approaches to the diagnosis,treatment and prognosis of patients with glioblastoma remain urgent clinical requirements.The tripartite motif-containing(TRIM)family proteins are defined by a conserved domain architecture composed of three zinc-binding regions: a RING finger,one or two B-boxes,and a coiled-coil domain.Accumulating evidence indicates that TRIM family proteins play important roles in various physiological processes,including cell proliferation,migration,invasion,apoptosis and differentiation,and the cell cycle.TRIM22,which contains RING finger,B-box,and coiled-coil domains,is a member of the TRIM family and has been reported as a vital transcriptional regulator involving in many biological processes.PI3K/AKT signaling is a classical pathway involved in variety of biological process and functions,including proliferation,differentiation,survival,and motility.Epithelial–mesenchymal transition(EMT)is a key process that occurs during the development of organisms and the progression of epithelial tumors to metastatic cancers.EMT involves disruption of the cytoskeleton,intercellular adhesions and normal expression of transcriptional factors,and may be an important factor contributing to glioma tumorigenesis,metastasis,and chemotherapy resistance.Here,we identified upregulation of TRIM22 in glioblastoma tissues and cell lines,and found that ectopic TRIM22 expression induced glioblastoma cell proliferation,invasion and migration by activating PI3K/AKT and EMT.Methods: 1.TRIM22 expression in glioblastoma specimens and normal brain tissues was analyzed by the TCGA datasets.Expression of TRIM22 in m RNA and protein was measured by q RT-PCR and Western Blot in U87 and U251 cells,comparing to normal human astrocytes(NHAs,control).2.The two kinds of TRIM22-si RNA were transfected into U87 and U251 cells.The transfection efficacy of TRIM22-si RNA was examined by q RT-PCR and Western Blot respectively.3.The two kinds of TRIM22-si RNA were transfected into U87 and U251 cells.Cell Viability Assay(CCK8)and Colony Formation Assay were carried out to investigate the role of TRIM22 upon glioblastoma cell proliferation.4.The wound healing assay and Transwell invasion assay were carried out to measure the alterance of glioblastoma cell invasion and migration ability after TRIM22 knockdown by two kinds of TRIM22-si RNA.5.Western blot assay were used to examine the change of PI3K/AKT and EMT markers after inhibiting TRIM22 in U87 and U251 cells.Results: 1.TRIM22 was significant increased in glioblastoma patient compared with normal brain tissues according to TCGA datasets.Consistent with the data analysis,the experssion of TRIM22 in U87 and U251 was obviously incareased compared with the normal human astrocytes in both of m RNA expression level and protein expression level.2.U87 and U251 transfected with two kinds of TRIM22-si RNA show low expression of TRIM22 at m RNA expression level and protein expression level 3.Downregulation of TRIM22 by TRIM22-si RNA remarkly suppressed the proliferation ability of U87 and U251 cells assessed by Cell Viability Assay and Colony Formation Assay..4.Silencing TRIM22 expression by si RNA significantly reduced the migration and invasion of U87 and U251 cell assessed by the wound healing assay and Transwell invasion assay.5.Western blot assay showed that inhibtion of TRIM22 by si RNA dramaticly block the PI3K/AKT pathway and the EMT process.Conclusions: 1.TRIM22 is overexpressed in GBM tissues and glioblastoma cell lines U87 and U251.2.Inhibition of TRIM22 reduced proliferation capability of U87 and U251.3.TRIM22 depletion downregulate the migration and invasion of U87 and U251.4.The promoter of TRIM22 in proliferation,invasion and migration of glioblastoma is associated with the PI3K/AKT pathway and the EMT process..