# Mutations in the TP53, VEGFA, and CTH Genes as Key Molecular Markers for the Diagnosis of Glioblastoma

## TL;DR

This study identifies mutations in TP53, VEGFA, and CTH genes as potential biomarkers for diagnosing and understanding glioblastoma, a deadly brain cancer.

## Contribution

The study reports novel mutations in TP53, VEGFA, and CTH genes and their potential role as diagnostic markers for glioblastoma.

## Key findings

- GBM patients showed higher neutrophil and monocyte counts and lower lymphocyte counts compared to healthy individuals.
- TP53, VEGFA, and CTH genes exhibited mutations, with TP53 showing the highest prevalence and a novel mutation identified.
- Gene expression analysis revealed significantly higher levels of TP53 and VEGFA in GBM patients.

## Abstract

Background

Brain cancer, particularly glioblastoma (GBM), is a global health problem. Despite therapy advances, GBM patients have a poor prognosis. The progression and etiology of GBM may be linked to gene polymorphisms in the VEGFA, TP53, and CTH genes, among others. However, the genetic variations and their interaction in GBM are not fully understood. This study examines the effects of mutations in the VEGFA, TP53, and CTH genes on GBM.

Methodology

Tissue and blood samples were obtained for hematological, biochemical, and genetic analysis from 18 patients diagnosed with GBM as well as 28 healthy individuals. Standard methods were adopted to perform hematological and biochemical analyses, whereas mutational landscape and expression profiles were obtained from publicly accessible databases. Tissue samples were processed for genomic DNA extraction, and genotype determination was carried out through conventional polymerase chain reaction (PCR) and Sanger sequencing.

Results

The study involved 18 patients with grade IV GBM before treatment and 28 healthy individuals. The patients consisted of 11 men (61%) and seven females (39%), while healthy individuals included 14 (50%) males and 14 (50%) females. Sixty-seven percent of patients were under 50, 17% between 51 and 60, and 17% over 61, compared to healthy individuals who were 61% under 50, 7% between 51 and 60, and 32% over 60. GBM patients showed higher neutrophil and monocyte counts (median 81% (63.9, 83.5) and 4.2% (3.8-7.3)), respectively, and lower lymphocyte counts (median 13.4% (8.8, 28.40)) compared to controls. The median values of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) showed no significant differences between the control and GBM groups. GBM patients had significantly higher median CRP levels of 2.55 (1.6, 98) than controls. Analysis of databases revealed a high prevalence of mutations in TP53, with splice region variants, missense variants, and intron variants being the most common. VEGFA and CTH also displayed mutations, primarily missense and intron variants. Gene expression analysis showed significantly higher levels of TP53 and VEGFA in GBM patients compared to controls. CTH expression also exhibited a slight increase in GBM patients. Sanger sequencing identified three mutations in the TP53 gene, including a novel mutation (11915C>A) not previously reported in external databases. Additionally, novel mutations were found in the VEGFA (841G>GA, 919T>TG) and CTH (28398A>AC, 28399A>AT) genes.

Conclusions

This study highlights the immune dysregulation, inflammation, and genetic variations in GBM. The findings emphasize the potential importance of the TP53, VEGFA, and CTH genes as targets for therapies and diagnostic biomarkers of GBM. Further study is necessary to comprehend these genetic variations' functional implications and their use in personalized GBM treatment.