| BPTF(Bromodomain PHD-finger transcription factor)is an important epigenetic regulator,it is involved in the regulation of chromosome transcription and chromatin remodeling.It is highly expressed in the fetal brain,and is an important epigenetic regulator.It has the important function of regulating the development of the embryo and central nervous system.The abnormal expression of BPTF may lead to the abnormal development of the central nervous system and tumorigenesis.However,there has been no report about BPTF and glioma at present.In order to explore the role of BPTF in glioma,firstly,this study searched the expression of BPTF in glioma through bioinformatics in the public tumor database Oncomine,and found that the expression of BPTF in glioma was significantly higher than that in normal brain tissues.Then,the expression of BPTF in the tissues of glioma patients was detected by real-time PCR and Western blot.The results showed that the expression of BPTF mRNA and protein in glioma was significantly higher than that in normal brain tissues.To investigate the role of BPTF in gliomas,the expression of BPTF in paraffin-embedded samples of 113 glioma patients was analyzed by immunohistochemistry.The results indicated that BPTF was positive in most glioma tissues and negative in normal brain tissues.Based on this,the paraffin-embedded samples of glioma were split into the high-expression and low-expression groups.Further statistical analysis of the relationship between the expression of BPTF and the clinicopathological features of glioma showed that the expression of BPTF correlated significantly with the WHO grade and tumor size.The Kaplan-Meer survival curve and log-rank test results suggusted that higher expression of BPTF predicts shorter postoperative survival and progression-free survival.In addition,the expression of BPTF was found to be an independent prognostic factor for the overall survival rate and progression free survival rate of glioma patients,based on single-factor and multiple-factor regression analysis,suggesting that BPTF could be used as a biomarker to predict the prognosis of glioma patients.To further study the specific role of BPTF in gliomas,the expression of BPTF in human glioma cell lines was tested and screened.Following this,the U251 cell line with BPTF overexpression and LN229 cell line with BPTF knockdown were established.Through MTT assay,plate colony formation assay and detection the expression level of Ki67,it was found that overexpression of BPTF significantly facilitated the proliferation capacity of LN229,while knockdown of BPTF significantly inhibited the proliferation capacity of U251.Additionally,through the Transwell migration experiment,wound healing experiment and Transwell invasion experiment,it was found that overexpression of BPTF significantly improved the motility?migration and invasion ability of LN229 cells.Conversely,knockdown of the BPTF expression significantly reduced the motility,migration and invasion ability of U251 cells.Furthermore,through the Transwell invasion experiment,it was found that overexpression of BPTF significantly promoted the invasion ability of LN229 cells,while knockdown of BPTF significantly reduced the invasion ability of U251 cells.Based on this,it was concluded that BPTF has biological functions of promoting glioma proliferation,motility,migration and invasion capacity.The expression of vimentin and E-cadherin,markers of epithelial mesenchymal transition(EMT),was detected by cell morphology,real-time PCR and Western blot.It was preliminarily confirmed that BPTF might induce EMT-like changes in glioma cells in vitro.In order to investigate the molecular mechanism of BPTF promoting glioma proliferation,invasion and metastasis,analyses of the bioinformatics were carried out,it was found that BPTF and c-myc might have a close interaction.Meanwhile,through the ChIP database Ominer and ChIP-Atlas,it was found that BPTF could be combined with c-MYC promoter regions and regulate the transcription actication.Furthermore,real-time PCR and western blot experiments showed that the expression of c-MYC in LN229 cells with overexpression of BPTF was increased significantly,while the expression of c-MYC in U251 cells with knockdown of BPTF decreased significantly.While detecting c-MYC signaling pathway to promote proliferation,invasion and metastasis of tumor and EMT key regulatory elements,the results showed that after BPTF overexpressed in LN229 cells,the mRNA and protein expression of c-MYC,Cyclin D1,MMP2,MMP7 and snail were increased obviously,while knockdown of BPTF in U251 cells,the mRNA and protein expressions of c-MYC,Cyclin D1,MMP2,MMP7 and Snail were significantly down-regulated.The above results further suggested that BPTF might promote glioma proliferation,invasion and metastasis,and induce EMT by activating the c-MYC signaling pathway,and ultimately promote glioma progression and lead to poor prognosis of glioma patients.In conclusion,this study has initially demonstrated that BPTF may serve as an important prognostic marker and potential therapeutic target for glioma,which has important potential clinical application value. |
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