Adult Human Glioblastomas Harbor Radial Glia-like Cells

Stationary-to-migratory transition in glioblastoma stem-like cells driven by a fatty acid-binding protein 7-RXRα neurogenic pathway

BACKGROUND

Glioblastoma (GBM) stem-like cells (GSCs) are crucial drivers of treatment resistance and tumor recurrence. While the concept of "migrating" cancer stem cells was proposed a decade ago, the roles and underlying mechanisms of the heterogeneous populations of GSCs remain poorly defined.

METHODS

Cell migration using GBM cell lines and patient-derived GSCs was examined using Transwell inserts and the scratch assay. Single-cell RNA sequencing data analysis were used to map GSC drivers to specific GBM cell populations. Xenografted mice were used to model the role of brain-type fatty acid-binding protein 7 (FABP7) in GBM infiltration and expansion. The mechanism by which FABP7 and its fatty acid ligands promote GSC migration was examined by gel shift and luciferase gene reporter assays.

RESULTS

A subpopulation of FABP7-expressing migratory GSCs was identified, with FABP7 upregulating SOX2, a key modulator for GBM stemness and plasticity, and ZEB1, a prominent factor in GBM epithelial-mesenchymal transition and invasiveness. Our data indicate that GSC migration is driven by nuclear FABP7 through activation of RXRα, a nuclear receptor activated by polyunsaturated fatty acids (PUFAs).

CONCLUSION

Infiltrative progression in GBM is driven by migratory GSCs through activation of a PUFA-FABP7-RXRα neurogenic pathway.

Cytohesin-4 Upregulation in Glioma-Associated M2 Macrophages Is Correlated with Pyroptosis and Poor Prognosis

Cytohesin-4 (CYTH4) is a member of the PSCD family. Members of this family appear to mediate the regulation of protein sorting and membrane trafficking. In previous studies, CYTH4 has been linked with multiple brain diseases, but not glioma, the most common type of brain tumor. We utilized multiple glioma single-cell RNA sequencing datasets and bulk data from the TCGA and CGGA and conducted GSEA and KEGG and GO analyses. Biomarker potential was tested via ROC curve analysis. Radar plots were used to study TMB and MSI correlations. Immune cell studies were conducted using CIBERSORT. All statistical analyses were performed in R software and GraphPad Prism 9. CYTH4 was overexpressed in the glioma macrophage population in several single-cell RNA sequencing datasets and was most correlated with M2 macrophages. CYTH4 expression was higher in tumor tissues and was correlated with survival and WHO grade. ROC curves suggested CYTH4 overexpression to be a potential glioma biomarker. GSEA results indicated a relationship between CYTH4 and apoptosis, and PPI analysis supported a pyroptosis correlation. KEGG and GO analysis results linked CYTH4 with antigen processing and presentation and neutrophil activities. In summary, the study identified a CYTH4/pyroptosis/M2 macrophage axis. CYTH4 was upregulated in M2 macrophages in glioma and affected pyroptosis. CYTH4 overexpression is a potential biomarker predicting a poor prognosis.

The ALDH Family Contributes to Immunocyte Infiltration, Proliferation and Epithelial-Mesenchymal Transformation in Glioma

Gliomas are malignant tumors that originate from the central nervous system. The aldehyde dehydrogenase family has been documented to affect cancer progression; however, its role in gliomas remains largely unexplored. Bulk RNA-seq analysis and single-cell RNA-Seq analysis were performed to explore the role of the aldehyde dehydrogenases family in gliomas. Training cohort contained The Cancer Genome Atlas data, while data from Chinese Glioma Genome Atlas and Gene Expression Omnibus were set as validation cohorts. Our scoring system based on the aldehyde dehydrogenases family suggested that high-scoring samples were associated with worse survival outcomes. The enrichment score of pathways were calculated by AUCell to substantiate the biofunction prediction results that the aldehyde dehydrogenases family affected glioma progression by modulating tumor cell proliferation, migration, and immune landscape. Tumor immune landscape was mapped from high-scoring samples. Moreover, ALDH3B1 and ALDH16A1, two main contributors of the scoring system, could affect glioblastoma cell proliferation and migration by inducing cell-cycle arrest and the epithelial-mesenchymal transition. Taken together, the aldehyde dehydrogenases family could play a significant role in the tumor immune landscape and could be used to predict patient prognosis. ALDH3B1 and ALDH16A1 could influence tumor cell proliferation and migration.

Pentraxin 3 Promotes Glioblastoma Progression by Negative Regulating Cells Autophagy

Glioblastoma is the most malignancy tumor generated from the central nervous system along with median survival time less than 14.6 months. Pentraxin 3 has been proved its association with patients’ poor survival outcome in various tumor. Recently, several studies revealed its association with glioblastoma progression but the mechanism is remained unknown. Autophagy is a programmed cells death and acts critical role in tumor progression. In this study, pentraxin 3 is recognized as prognostic prediction biomarker of glioblastoma and can promote glioblastoma progression through negative modulating tumor cells autophagy. Transcription factor JUN is assumed to participate in cells autophagy modulation by regulating pentraxin 3 expression. This work reveals novel mechanism of pentraxin 3 mediated glioblastoma progression. Furthermore, JUN is identified as potential transcription factor involves in pentraxin 3 mediated tumor cells autophagy.