Comprehensively investigating the expression levels and the prognostic role of transforming growth factor beta-induced (TGFBI) in glioblastoma multiforme

Understanding the Role of Endothelial Cells in Glioblastoma: Mechanisms and Novel Treatments

Glioblastoma is a highly aggressive neoplasm and the most common primary malignant brain tumor. Endothelial tissue plays a critical role in glioblastoma growth and progression, facilitating angiogenesis, cellular communication, and tumorigenesis. In this review, we present an up-to-date and comprehensive summary of the role of endothelial cells in glioblastomas, along with an overview of recent developments in glioblastoma therapies and tumor endothelial marker identification.

TGF-β based risk model to predict the prognosis and immune features in glioblastoma

Background

Transforming growth factor-β (TGF-β) is a multifunctional cytokine with an important role in tissue development and tumorigenesis. TGF-β can inhibit the function of many immune cells, prevent T cells from penetrating into the tumor center, so that the tumor cells escape from immune surveillance and lead to low sensitivity to immunotherapy. However, its potential roles in predicting clinical prognosis and tumor microenvironment (TME) immune features need to be deeply investigated in glioblastoma (GBM).

Methods

The TCGA-GBM dataset was obtained from the Cancer Genome Atlas, and the validation dataset was downloaded from Gene Expression Omnibus. Firstly, differentially expressed TGF-β genes (DEGs) were screened between GBM and normal samples. Then, univariate and multivariate Cox analyses were used to identify prognostic genes and develop the TGF-β risk model. Subsequently, the roles of TGF-β risk score in predicting clinical prognosis and immune characteristics were investigated.

Results

The TGF-β risk score signature with an independent prognostic value was successfully developed. The TGF-β risk score was positively correlated with the infiltration levels of tumor-infiltrating immune cells, and the activities of anticancer immunity steps. In addition, the TGF-β risk score was positively related to the expression of immune checkpoints. Besides, the high score indicated higher sensitivity to immune checkpoint inhibitors.

Conclusions

We first developed and validated a TGF-β risk signature that could predict the clinical prognosis and TME immune features for GBM. In addition, the TGF-β signature could guide a more personalized therapeutic approach for GBM.

Implication of lncRNA ZBED3-AS1 downregulation in acquired resistance to Temozolomide and glycolysis in glioblastoma

Temozolomide (TMZ) is the recommended drug for glioblastoma (GBM) treatment, but its clinical effect is restricted due to drug resistance. This research studies the effects of long non-coding RNA (lncRNA) ZBED3-AS1 and its related molecules on acquired TMZ resistance in glioblastoma (GBM). ZBED3-AS1 was identified to be downregulated in TMZ-resistant GBM cells by analyzing GSE113510 and GSE100736 datasets. ZBED3-AS1 downregulation was detected in TMZ-resistant GBM tissues and cell lines (U251/TMZ and U87/TMZ). ZBED3-AS1 knockdown promoted, whereas its overexpression suppressed TMZ resistance, viability and mobility, and glycolytic activity of TMZ-resistant cells. ZBED3-AS1 bound to Spi-1 proto-oncogene (SPI1) but did not affect its expression. Instead, it blocked SPI1-mediated transcriptional activation of thrombomodulin (THBD). SPI1 and THBD increased TMZ resistance and glycolysis in TMZ-resistant cells. Either ZBED3-AS1 overexpression or SPI1 knockdown in U87/TMZ cells blocked the growth of orthotopic and subcutaneous xenograft tumors in nude mice. In conclusion, this study demonstrates that ZBED3-AS1 downregulation and THBD activation is linked to increased TMZ resistance and glycolysis in GBM cells.

Pan-Cancer Analysis of the Associations of TGFBI Expression With Prognosis and Immune Characteristics

Transforming growth factor-beta-induced (TGFBI) protein has important roles in tumor growth, metastasis, and immunity. However, there is currently no pan-cancer evidence regarding TGFBI. In this study, we conducted a pan-cancer analysis of TGFBI mRNA and protein expression and prognoses of various cancer types using public databases. We also investigated the associations of TGFBI expression with tumor microenvironment (TME) components, immune cell infiltration, tumor mutational burden (TMB), and microsatellite instability (MSI), along with the TGFBI genetic alteration types. The results showed that TGFBI expression varied among different cancer types, and it was positively or negatively related to prognosis in various cancers. TGFBI expression was also significantly correlated with TME components, TMB, MSI, immune cell infiltration, and immunoinhibitory and immunostimulatory gene subsets. These findings indicate that TGFBI participates in various immune responses and it may function as a prognostic marker in various cancers. The findings may be useful for developing immunotherapies that target TGFBI.

The embryonic stem cell microenvironment inhibits mouse glioma cell proliferation by regulating the PI3K/AKT pathway

BACKGROUND

Glioblastoma multiforme (GBM) is the most common malignant tumor of the central nervous system, accounting for 48.6% of malignant tumors. The current standard treatment plan includes the widest range of safe surgical resection, supplemented by local brain radiotherapy and temozolomide concurrent chemotherapy; this can cause serious side effects. Even so, the median survival time of GBM patients is only 8 months, and the 5-year survival rate is only 5.5%. It is imminent to find new treatments. Early studies have shown that chicken and zebrafish embryos can reprogram cancer cells into a non-tumorigenic phenotype through the embryonic microenvironment. However, the effect of embryonic stem cell microenvironment on GBM and its possible mechanism are not clear.

METHODS

In this study, the glioblastoma cell line, U118, in the brain was investigated. There were four experimental groups: GB, GE, GA and GT. U118 cells were harvested after culturing for 72 hours. Cell proliferation, apoptosis, reactive oxygen species (ROS) were examined using vasculogenic mimicry assays, quantitative real-time polymerase chain reaction (QRT-PCR), western blotting (WB) and flow cytometry. The differences in the biological function of U118 cells and the PI3K/protein kinase B (AKT) signaling pathway were compared between the groups.

RESULTS

Compared with the GB control group, the GE co-culture group and GT chemotherapy group showed reduced cell proliferation, increased apoptosis, increased ROS, as well as decreased or inhibited vasculogenic mimicry. Expressions of cyclin B1 and cyclin D1 were also notably reduced, while that of Bax, Bcl-2, p53, Caspase-3, GSK-3β, p21, and p27 were significantly increased. Moreover, the expression of PI3K, AKT, and mTOR were markedly decreased, whereas expression of PTEN increased considerably. Also, the expression of positive regulatory factors significantly increased, however negative regulatory factors decreased in the GA group compared to the GE group.

CONCLUSIONS

The ESC microenvironment reverses glioma malignancy, partially via inhibition of the PI3K signaling pathway. Our study may have a significant impact and important clinical implications for cell therapy in the treatment of glioma.