Searching for Stemness-Associated mRNAs in Glioma Tumor Tissue

Abstract

Introduction Glioblastoma (GB) is the most common and the most aggressive form of brain cancer. Although these days the treatment for glioblastoma is improving, the median survival of patients still remains 12-15 months. Glioma stem cells contribute to such a short survival rate. These cells are responsible for glioblastoma initiation, tumor development, and resistance to treatment. Aim The aim of this study was to identify mRNAs that are related to glioma stem cells to find new molecular biomarkers for gliomas. Methods Glioblastoma and glioma stem cell lines were used to find potentially related mRNA to glioma stem cells. Differential gene expression analysis (DESeq2) of total 7903 genes, identified 121 significantly stemness-associated target genes according to Nanopore sequencing data. The top three candidates were subsequently selected for validation in glioma tumor tissues. Total RNA was isolated from 100 mg of snap-frozen patients’ tumor tissue using TRIzol according to the manufacturers’ instructions. The quality, quantity, and purity were measured on a 1.5% agarose gel and Nanodrop 2000 spectrophotometer. After, cDNA was synthesized. mRNA expression levels were detected using RTqPCR using glioblastoma (n= 31), II (n=12), and III (n=5) grade glioma patients’ samples. Results After dRNA Nanopore sequencing data analysis, we identified top 3 the most significant stemness- related mRNAs (SERPINE1, ITGA3, and PMP2). mRNA expression levels significantly differed in glioma tumor samples (p<0.05) according to their pathology, which is proposing suitability of target mRNAs for glioma stratification. High expression of the analyzed target genes was associated with poorer prognosis in glioma patients. Conclusions In this study, we identified glioma stem cells specific mRNA target genes: SERPINE1, ITGA3, and PMP2 that have an impact on gliomagenesis. Although SERPINE1 and ITGA3 genes have been confirmed to be associated with stemness, validation in tumor tissues is still lacking. And to our knowledge, validation of the PMP2 gene in different glioma tumor grades has not been performed at all. Finding new clinical biomarkers can help to reflect patient prognosis and better predict therapeutic response.