Silencing PLEKHA4 Inhibits Malignant Biological Behavior Of Glioma Through APC/Wnt/β-catenin Axis

Objective: As the primary intracranial tumor with the highest incidence in adults,glioma has a high degree of malignancy and a poor prognosis.Even after standard surgical resection combined with postoperative radiotherapy and chemotherapy,the benefit of patients is still limited.Therefore,it is of great significance to find more new potential therapeutic targets for glioma.A large number of experiments have demonstrated that Wnt/β-catenin signaling pathway is involved in the regulation of epithelial interstitial transformation,tumor cell metabolism,proliferation,apoptosis,migration,invasion,metastasis,angiogenesis,the formation of tumor microenvironment,immune escape,stemness maintenance,radiotherapy and chemotherapy tolerance,and relapse,which almost covers the whole process of tumor regulation.Therefore,it has become the focus of this study to explore a new mechanism to inhibit the development of glioma by targeting Wnt/β-catenin signaling pathway.Methods: Weighted gene coexpression analysis was used to identify the modules closely associated with gliomas.Multiple glioma data sets were used to validate the results.The gene expression boxplot and survival analysis diagram were used to observe the relationship between the expression level of candidate genes and tumor grade and overall survival time of patients.Gene set enrichment analysis and gene expression correlation analysis of multiple data sets are used to explore the potential function and mechanism of the target.The transcription and translation levels of candidate genes in glioma cells were detected by RT-q PCR and Western blot.The apoptosis level of glioma cells in each experimental group was detected by flow cytometry.Transwell was used to detect the migration and invasion ability of glioma cells in each experimental group.CCK8 was used to detect the proliferative ability of glioma cells in each experimental group.The experiment of subcutaneous tumor formation in nude mice verified the actual function of core genes in vivo.Results: Weighted gene co-expression analysis showed that the genes in the turquoise module were closely related to the overall survival time and tumor grade of patients.Bioinformatics analysis of multiple data sets showed that PLEKHA4 was positively correlated with tumor grade and negatively correlated with overall survival time of patients.Gene set enrichment analysis showed that PLEKHA4 may be involved in the positive regulation of Wnt pathway.Our subsequent experiments demonstrated that PLEKHA4 expression was significantly up-regulated in glioma cells.Silencing PLEKHA4 can induce apoptosis of glioma cells,weaken the migration,invasion and proliferation of glioma cells,and inhibit the growth of mouse glioma tumor.Mechanically,PLEKHA4 silencing can improve the transcription and translation level of APC and inhibit the activation of Wnt/β-catenin signaling pathway,resulting in the decreased expression of downstream target genes CD44,MMP7,MMP9,VEGF and the core gene CTNNB1 of this pathway.Conclusion: This study not only verified the expression of PLEKHA4 in glioma cells and its inhibitory effect on the growth of glioma cells for the first time,but also revealed that PLEKHA4 can activate the Wnt/β-catenin signaling pathway through the negative regulation of APC,which provides new insights for the targeted therapy of glioma.