Molecular genetics of low-grade gliomas: genomic alterations guiding diagnosis and therapeutic intervention. 11th annual Frye-Halloran Brain Tumor Symposium

Overexpression of GINS4 is associated with poor prognosis and survival in glioma patients

Background

GINS4, an indispensable component of the GINS complex, is vital for a variety of cancer. However, no known empirical research has focused on exploring relationships between GINS4 and glioma. Thus, this study aims to understand and explain the role of GINS4 in glioma.

Method

First, we used the data in the CGGA, TCGA, GEO, GEPIA, and HPA databases to explore the expression level of GINS4 in glioma, the correlation between GINS4 expression and the clinical features of glioma, its impact on the survival of glioma patients, and verified the analysis results through RT-qPCR, IHC, and meta-analysis. Subsequently, GSEA enrichment analysis is used to find the potential molecular mechanism of GINS4 to promote the malignant process of glioma and the anti-glioma drugs that may target GINS4 screened by CMap analysis. Moreover, we further explored the influence of the GINS4 expression on the immune microenvironment of glioma patients through the TIMER database.

Results

Our results suggested that GINS4 was elevated in glioma, and the overexpression of GINS4 was connected with a vast number of clinical features. The next, GINS4 as an independent prognostic factor, which can result in an unfavorable prognosis of glioma. Once more, GINS4 may be participating in the oncogenesis of glioma through JAK-STAT signaling pathways, etc. 6-thioguanine, Doxazosin, and Emetine had potential value in the clinical application of drugs targeting GINS4. Finally, the expression exhibited a close relationship with some immune cells, especially Dendritic cells.

Conclusion

GINS4 is an independent prognostic factor that led to a poor prognosis of glioma. The present study revealed the probable underlying molecular mechanisms of GINS4 in glioma and provided a potential target for improving the prognosis of glioma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00378-0.

Abnormally high expression of HOXA2 as an independent factor for poor prognosis in glioma patients

In recent years, studies have revealed HOXA2 as a new oncogene, but its function is unknown in gliomas. We aimed to reveal the relationship between HOXA2 and glioma based on the Chinese Glioma Genome Atlas(CGGA) and the cancer genome atlas (TCGA). HOXA2 expression data and clinically relevant information of glioma patients were obtained from the CGGA and TCGA containing 1447 glioma tissues and five non-tumor brain tissues. The Wilcox or Kruskal tests were used to detect the correlation between the HOXA2 expression level and clinical data of glioma patients. the Kaplan-Meier method were used to examine the relationship between HOXA2 and overall patient survival. Gene set enrichment analysis (GSEA) was conducted to indirectly reveal the signaling pathways involved in HOXA2, and RT-PCR was used to detect HOXA2 expression in gliomas and non-tumor brain tissues. High HOXA2 expression was found to be positively correlated with clinical grade, histological type, age, and tumor recurrence, but negatively correlated with 1p19 codeletion and isocitrate dehydrogenase mutation status.RT-PCR results showed that HOXA2 expression levels were significantly higher in tumor tissues than in non-tumor brain tissues. GSEA showed that HOXA2 promoted the activation of the activation of the JAK-STAT-signaling pathway, focal adhesion, cell-adhesion-molecules-CAMS pathway, cytosolic DNA sensing pathway, and natural killer cell-mediated cytotoxicity. This study revealed for the first time that the novel oncogene,HOXA2, leads to poor prognosis in gliomas, and can be used as a biomarker for the diagnosis and treatment of gliomas.

Isocitrate Dehydrogenase Mutations in Low-Grade Gliomas Correlate With Prolonged Overall Survival in Older Patients

BACKGROUND

Older age has been associated with worse outcomes in low-grade gliomas (LGGs). Given their rarity in the older population, determining optimal treatment plans and patient outcomes remains difficult.

OBJECTIVE

To retrospectively study LGG survival outcomes in an older population stratified by molecular genetic profiles.

METHODS

We included patients age ≥40 yr with pathologically confirmed World Health Organization grade II gliomas treated at a single institution between 1995 and 2015. We collected tumor genomic information when available.

RESULTS

Median overall survival for the entire group (n = 111, median age 51 yr, range 40-77 yr) was 15.75 yr with 5- and 10-yr survival rates of 84.3% and 67.7%, respectively. On univariate analysis, patients with isocitrate dehydrogenase (IDH) mutation had significantly increased survival compared to IDH wildtype (hazard ratio [HR] 0.17 [0.07-0.45], P < .001). Older age, seizure at presentation, larger tumor size, IDH wildtype, biopsy only, chemotherapy, and radiation were significantly associated with shorter survival based on univariate analyses. In patients with known IDH status (n = 73), bivariate analysis of IDH mutation status and age showed only IDH status significantly influenced overall survival (HR 0.22 [0.07-0.68], P = .008). Greater surgical resection was predictive of survival, although extent of resection significantly correlated with IDH mutation status (odds ratio 7.5; P < .001).

CONCLUSION

We show that genomic alterations in LGG patients ≥40 occur at high rates like the younger population and predict a similar survival advantage. Maximizing surgical resection may have survival benefit, although feasibility of resection is often linked to IDH status. Given the importance of molecular genetics, a redefinition of prognostic factors associated with these tumors is likely to emerge.

An integrative molecular and genomic analysis of pediatric hemispheric low-grade gliomas: an update

Hemispheric low-grade gliomas account for the second most common location in pediatric low-grade gliomas (PLGGs) after the cerebellum. The pathological spectrum includes gangliogliomas, dysembryoplastic neuroepithelial tumors (DNETs), diffuse astrocytomas, pilocytic astrocytomas, and pleomorphic xanthoastrocytomas (PXAs), among others. Clinically, hemispheric PLGGs represent a well-recognized cause of intractable epilepsy in children and adolescents. With an excellent long-term outcome, surgery remains the cornerstone and patients with gross total resection typically do not need any further therapies. The recent literature about hemispheric PLGGs was reviewed to provide an up-to-date overview of the molecular and cell biology of these tumors. Hemispheric PLGGs can harbor multiple alterations involving BRAFV600E, FGFR, NTRK, MYB/MYBL1, IDH, and BRAF-KIAA1549 fusions. However, the clinical significance of most of these alterations is still to be defined. The role of RAS/MAPK mutations and other alterations in hemispheric PLGGs is of interest from diagnostic, prognostic, and therapeutic perspectives. Molecular testing for these tumors should be encouraged, since the findings can have an important impact not only in prognosis but also in therapeutic strategies.

From genomics to the clinic: biological and translational insights of mutant IDH1/2 in glioma

The characterization of the genomic alterations across all human cancers is changing the way that malignant disease is defined and treated. This paradigm is extending to glioma, where the discovery of recurrent mutations in the isocitrate dehydrogenase 1 (IDH1) gene has shed new light on the molecular landscape in glioma and other IDH-mutant cancers. The IDH1 mutations are present in the vast majority of low-grade gliomas and secondary glioblastomas. Rapidly emerging work on the consequences of mutant IDH1 protein expression suggests that its neomorphic enzymatic activity catalyzing the production of the oncometabolite 2-hydroxyglutarate influences a range of cellular programs that affect the epigenome, transcriptional programs, hypoxia-inducible factor biology, and development. In the brief time since its discovery, knowledge of the IDH mutation status has had significant translational implications, and diagnostic tools are being used to monitor its expression and function. The concept of IDH1-mutant versus IDH1-wild type will become a critical early distinction in diagnostic and treatment algorithms.

Glioma diagnostics and biomarkers: an ongoing challenge in the field of medicine and science

Glioma is the most common brain tumor. For the more aggressive form, glioblastoma, standard treatment includes surgical resection, irradiation with adjuvant temozolomide and, on recurrence, experimental chemotherapy. However, the survival of patients remains poor. There is a critical need for minimally invasive biomarkers for diagnosis and as measures of response to therapeutic interventions. Glioma shed extracellular vesicles (EVs), which invade the surrounding tissue and circulate within both the cerebrospinal fluid and the systemic circulation. These tumor-derived EVs and their content serve as an attractive source of biomarkers. In this review, we discuss the current state of the art of biomarkers for glioma with emphasis on their EV derivation.

Emerging insights into barriers to effective brain tumor therapeutics

There is great promise that ongoing advances in the delivery of therapeutics to the central nervous system (CNS) combined with rapidly expanding knowledge of brain tumor patho-biology will provide new, more effective therapies. Brain tumors that form from brain cells, as opposed to those that come from other parts of the body, rarely metastasize outside of the CNS. Instead, the tumor cells invade deep into the brain itself, causing disruption in brain circuits, blood vessel and blood flow changes, and tissue swelling. Patients with the most common and deadly form, glioblastoma (GBM) rarely live more than 2 years even with the most aggressive treatments and often with devastating neurological consequences. Current treatments include maximal safe surgical removal or biopsy followed by radiation and chemotherapy to address the residual tumor mass and invading tumor cells. However, delivering effective and sustained treatments to these invading cells without damaging healthy brain tissue is a major challenge and focus of the emerging fields of nanomedicine and viral and cell-based therapies. New treatment strategies, particularly those directed against the invasive component of this devastating CNS disease, are sorely needed. In this review, we (1) discuss the history and evolution of treatments for GBM, (2) define and explore three critical barriers to improving therapeutic delivery to invasive brain tumors, specifically, the neuro-vascular unit as it relates to the blood brain barrier, the extra-cellular space in regard to the brain penetration barrier, and the tumor genetic heterogeneity and instability in association with the treatment efficacy barrier, and (3) identify promising new therapeutic delivery approaches that have the potential to address these barriers and create sustained, meaningful efficacy against GBM.

Advances in genetic and epigenetic analyses of gliomas: a neuropathological perspective

Gliomas, the most common malignant primary brain tumors, are universally fatal once they progress from low-grade into high-grade neoplasms. In recent years, we have accumulated unprecedented data about the genetic and epigenetic abnormalities in gliomas; yet, our appreciation of how these deadly tumors arise is still rudimentary. One of the major deterrents in understanding gliomagenesis is the remarkably complex and heterogeneous molecular composition of gliomas, as well as their ability to change phenotypically as they progress and recur. In the past decade, several monumental studies have begun to define better glioma heterogeneity. Four distinct molecular subgroups have emerged: proneural, classical, mesenchymal, and neural; which have unique gene expression signatures and prognostic significance. Of these, gliomas of the proneural subtype, which encompass most grade II/III diffuse gliomas and secondary glioblastomas and often carry isocitrate dehydrogenase (IDH) mutations, have emerged as a distinct tumor subclass with a notably superior prognosis. Important molecular markers with prognostic relevance, such as mutant IDH1/2, have already been incorporated into clinical neuropathological practice. The recent molecular discoveries in gliomas have also emphasized the intimate link between epigenetics and genetics in gliomagenesis. Several of the novel genetic mutations described are responsible for distinct epigenetic remodeling in gliomas, the mechanisms of which are currently being elucidated. Importantly, these epigenetic and genomic alterations represent new and exciting drug targets for future therapeutic interventions in our continuous fight with this fatal malignancy.

New IDH1 I113T mutation associated with BRAF V600E mutation: new driver of gliomagenesis?

BACKGROUND

IDH mutations and BRAF mutations are classically mutually exclusive and usually associated with infiltrative or circumscribed gliomas and glioneuronal tumors respectively.

CASE REPORT

We report the case of a 26-year old man with intracranial hypertension revealing voluminous right frontal lesion. Surgical resection was performed and pathological examination found two distinct tumoral areas: a glioma-like area with calcification without mitosis; a second with pleomorphic glial cells with higher Mib index, high CD34 expression and endothelial proliferation. No necrosis was recorded. Molecular analyses revealed both IDH1 I113T and BRAF V600E mutations. Although this glioma was difficult to clarify, diagnosis of pleomorphic xanthoastrocytoma with anaplastic feature was suggested based on the association of some pathological feature (eosinophilic granular bodies, reticulin network and diffuse CD34 expression) and the BRAF V600E mutation.

CONCLUSION

We report a new IDH1 mutation associated with BRAF mutation in a very unusual glial tumor.