Impact of histopathological transformation and overall survival in patients with progressive anaplastic glioma

Identification of an IFN-β-associated gene signature for the prediction of overall survival among glioblastoma patients

Background

Brain glioblastoma multiforme (GBM) is the most common primary malignant intracranial tumor. The prognosis of this disease is extremely poor. While the introduction of β-interferon (IFN-β) regimen in the treatment of gliomas has significantly improved the outcome of patients; The mechanism by which IFN-β induces increased TMZ sensitivity has not been described. Therefore, the main objective of the study was to elucidate the molecular mechanisms responsible for the beneficial effect of IFNβ in GBM.

Methods

Messenger RNA expression profiles and clinicopathological data were downloaded from The Cancer Genome Atlas (TCGA) GBM and GSE83300 dataset from the Gene Expression Omnibus. Univariate Cox regression analysis and lasso Cox regression model established a novel 4-gene IFN-β signature (peroxiredoxin 1, Sec61 subunit beta, X-ray repair cross-complementing 5, and Bcl-2-like protein 2) for GBM prognosis prediction. Further, GBM samples (n=50) and normal brain tissues (n=50) were then used for real-time polymerase chain reaction experiments. Gene set enrichment analysis (GSEA) was performed to further understand the underlying molecular mechanisms. Pearson correlation was applied to calculate the correlation between the long non-coding RNAs (lncRNAs) and IFN-β-associated genes. An lncRNA with a correlation coefficient |R²|>0.3 and P<0.05 was considered to be an IFN-β-associated lncRNA.

Results

Patients in the high-risk group had significantly poorer survival than patients in the low-risk group. The signature was found to be an independent prognostic factor for GBM survival. Furthermore, GSEA revealed several significantly enriched pathways, which might help explain the underlying mechanisms. Our study identified a novel robust 4-gene IFN-β signature for GBM prognosis prediction. The signature might contain potential biomarkers for metabolic therapy and treatment response prediction for GBM patients.

Conclusions

In the present study, we established a novel IFN-β-associated gene signature to predict the overall survival of GBM patients, which may help in clinical decision making for individual treatment.

Salinomycin exhibits anti-angiogenic activity against human glioma in vitro and in vivo by suppressing the VEGF-VEGFR2-AKT/FAK signaling axis

Tumor angiogenesis plays a crucial role in tumor growth, progression and metastasis, and suppression of tumor angiogenesis has been considered as a promising anticancer strategy. Salinomycin (SAL), an antibiotic, displays novel anticancer potential against several human cancer cells in vitro and in vivo. However, little information concerning its anti-angiogenic properties is available. Therefore, the anti‑angiogenic effect of SAL and the underlying mechanism in human glioma were evaluated in the present study. The results indicated that SAL treatment significantly inhibited human umbilical vein endothelial cell (HUVEC) proliferation, migration, invasion and capillary-like tube formation. Further investigation on intracellular mechanisms showed that SAL markedly suppressed FAK and AKT phosphorylation, and downregulated vascular endothelial growth factor (VEGF) expression in HUVECs. Pretreatment of cells with a PI3K inhibitor (LY294002) and FAK inhibitor (PF562271) markedly enhanced SAL-induced inhibition of HUVEC proliferation and migration, respectively. Moreover, U251 human glioma xenograft growth was also effectively blocked by SAL treatment in vivo via inhibition of angiogenesis involving FAK and AKT depho-sphorylation. Taken together, our findings validated that SAL inhibits angiogenesis and human glioma growth through suppression of the VEGF-VEGFR2-AKT/FAK signaling axis, indicating the potential application of SAL for the treatment of human glioma.

Preoperative albumin-to-globulin ratio and prognostic nutrition index predict prognosis for glioblastoma

Objective

Impaired immunonutritional status has disadvantageous effects on outcomes for cancer patients. Preoperative albumin-to-globulin ratio (AGR) and the prognostic nutrition index (PNI) have been used as prognostic factors in various cancers. We aimed to evaluate the clinical significance of the AGR and PNI in glioblastoma.

Materials and methods

This retrospective analysis involved 166 patients. Demographic, clinical, and laboratory data were collected. AGR and the PNI were calculated as AGR = albumin/(total serum protein − albumin) and PNI = albumin (g/L) + 5 × total lymphocyte count (10⁹/L). Overall survival (OS) was estimated by Kaplan–Meier analysis. Receiver-operating characteristic analysis was used to assess the predictive ability of AGR and the PNI. Cox proportional-hazard models estimating hazard ratios (HRs) and 95% confidence intervals (CIs) were used for univariable and multivariable survival analyses.

Results

The cutoff values of AGR and PNI were 1.75 and 48. OS was enhanced, with high AGR (>1.75) and the PNI (>48) (P<0.001 for both). Areas under the receiver-operating characteristic curve for AGR and the PNI were 0.68 and 0.631 for 1-year survival and 0.651 and 0.656 for 2-year survival (P<0.05 for all), respectively. On multivariable analyses, both AGR and the PNI were independent predictors of OS (AGR, HR 0.785, 95% CI 0.357–0.979 [P=0.04]; PNI, HR 0.757, 95% CI 0.378–0.985 [P=0.039]). On subgroup analysis, AGR and the PNI were significant prognostic factors for OS in patients with adjuvant therapy (AGR P<0.001; PNI P=0.001).

Conclusion

Preoperative AGR and the PNI may be easy-to-perform and inexpensive indices for predicting OS with glioblastoma. AGR and the PNI could also help in developing good adjuvant-therapy schedules.

A novel brain tumour model in zebrafish reveals the role of YAP activation in MAPK- and PI3K-induced malignant growth

Somatic mutations activating MAPK and PI3K signalling play a pivotal role in both tumours and brain developmental disorders. We developed a zebrafish model of brain tumours based on somatic expression of oncogenes that activate MAPK and PI3K signalling in neural progenitor cells and found that HRASV12 was the most effective in inducing both heterotopia and invasive tumours. Tumours, but not heterotopias, require persistent activation of phospho (p)-ERK and express a gene signature similar to the mesenchymal glioblastoma subtype, with a strong YAP component. Application of an eight-gene signature to human brain tumours establishes that YAP activation distinguishes between mesenchymal glioblastoma and low grade glioma in a wide The Cancer Genome Atlas (TCGA) sample set including gliomas and glioblastomas (GBMs). This suggests that the activation of YAP might be an important event in brain tumour development, promoting malignant versus benign brain lesions. Indeed, co-expression of dominant-active YAP (YAPS5A) and HRASV12 abolishes the development of heterotopias and leads to the sole development of aggressive tumours. Thus, we have developed a model proving that neurodevelopmental disorders and brain tumours might originate from the same activation of oncogenes through somatic mutations, and established that YAP activation is a hallmark of malignant brain tumours.