Bromodomain containing 4 transcriptionally activated Deltex E3 ubiquitin ligase 2 contributes to glioma progression and predicts an unfavorable prognosis

BACKGROUND: Glioblastoma multiforme (GBM) is the most common type of glioma, and the most aggressive brain malignancy in adults. This study sought to identify novel survival-status related markers, and examine their function in glioma. METHODS: The gene expression, survival heatmaps, and Kaplan-Meier survival plots of the genes were analyzed by using gene expression profiling interactive analysis (GEPIA) dataset, Linked Omics. The single-cell data analysis and tumor immune infiltration analysis was conducted by Tumor Immune Estimation Resource (TIMER) dataset. DBTRG and U251 cells with silenced Deltex E3 ubiquitin ligase 2 (DTX2) expression were constructed and used for Cell Counting Kit 8 (CCK-8), and wound healing assay in vitro. Chromatin immunoprecipitation sequencing (ChIP-seq) analysis was used to explore the histone activation marks and transcription factors DTX2 promoter. Dual-luciferase assays were carried out to detect the luciferase activities of bromodomain containing 4 (BRD4) binding to DTX2. RESULTS: We first conducted a survival-status analysis to identify survival status-related genes in The Cancer Genome Atlas GBM and low-grade glioma data sets. A subsequent analysis identified 3 novel prognostic biomarkers; that is, DTX2, cytochrome P450 oxidoreductase, and Williams-Beuren syndrome chromosomal region 16 protein. In the validation Chinese Glioma Genome Atlas data sets, DTX2 showed the best performance, and was examined in a further analysis. Next, 3 short-hairpin ribonucleic acids were designed to silence DTX2 expression, and CCK-8 and wound-healing assays were applied to study the function of DTX2. We found that DTX2-silenced glioma cells exhibited a significant decrease in their growth and migration capabilities. Finally, the molecular basis for increased DTX2 in glioma was investigated via ChIP-Seq analysis and luciferase assays. The analysis revealed that DTX2 was transcriptionally activated by BRD4. CONCLUSIONS: In conclusion, BRD4 transcriptionally activates DTX2, contributes to glioma progression, predicts an unfavorable prognosis, and could provide new options for glioma prognosis prediction and treatment.