👤 Anja Bukovac

Epithelial to mesenchymal transition (EMT) plays a critical role in tumor progression and metastasis, including in gliomas. To examine and interpret data on major genes involved in EMT and associate their changes with low-grade (LGG) and/or high-grade (HGG) gliomas, data from the cBioPortal-a publicly available database for tumor genomics and transcriptomics, were collected for 13 genes: CDH1, CDH2, CTNNB1, LEF1, NOTCH1, SNAI1, SNAI2, SOX2, TJP1/ZO1, TWIST1, VIM, ZEB1, and ZEB2. The dataset included mutations, copy number alterations (CNA), and changes in transcript levels reported for each gene. The genes were additionally validated by gene expression on the GlioVis portal, STRING protein network analysis, survival analysis, and experimentally with qRT-PCR. Glioblastoma and diffuse glioma harbored changes in all 13 analyzed genes, while anaplastic oligodendroglioma and anaplastic astrocytoma in 46.15%, oligodendroglioma in 23.08%, and oligoastrocytoma in 15.38%. NOTCH1 and SOX2 were most affected by changes. The NOTCH1 gene was statistically more frequently changed compared to CDH1, CTNNB1, and ZEB1 (p < 0.05). The virtual study showed that alterations in NOTCH1 and LEF1 were associated with LGG, while alterations in CDH1, CTNNB1, TJP1, TWIST1, SOX2, VIM, ZEB1, and ZEB2 were associated with HGG. Differential expression analysis stratified for IDH1 mutations showed that IDH1-mutant glioblastoma had significantly lower CDH2, LEF1 and SNAI1 expression, and higher ZEB1. Gene expression in different glioblastoma subtypes showed that the TJP1/ZO1 gene was associated with the classical subtype, while ZEB2 was associated with the proneural subtype. qRT-PCR confirmed GlioVis mRNA expression data for NOTCH1, SOX2, CDH1, CTNNB1, TJP1/ZO-1, VIM, TWIST1, and partially for SNAI1 (SNAIL), SNAI2, and CDH2. Our study shows consistent changes in genes involved in EMT in gliomas of different grades. Additional research is needed to confirm the knowledge brought by this study. Show less

Postreplicative mismatch repair safeguards the stability of our genome. The defects in its functioning will give rise to microsatellite instability. In this study, 50 meningiomas were investigated for microsatellite instability. Two major mismatch repair genes, MLH1 and MSH2, were analyzed using microsatellite markers D1S1611 and BAT26 amplified by polymerase chain reaction and visualized by gel electrophoresis on high-resolution gels. Furthermore, genes DVL3 (D3S1262), AXIN1 (D16S3399), and CDH1 (D16S752) were also investigated for microsatellite instability. Our study revealed constant presence of microsatellite instability in meningioma patients when compared to their autologous blood DNA. Altogether 38% of meningiomas showed microsatellite instability at one microsatellite locus, 16% on two, and 13.3% on three loci. The percent of detected microsatellite instability for MSH2 gene was 14%, and for MLH1, it was 26%, for DVL3 22.9%, for AXIN1 17.8%, and for CDH1 8.3%. Since markers also allowed for the detection of loss of heterozygosity, gross deletions of MLH1 gene were found in 24% of meningiomas. Genetic changes between MLH1 and MSH2 were significantly positively correlated (p = 0.032). We also noted a positive correlation between genetic changes of MSH2 and DVL3 genes (p = 0.034). No significant associations were observed when MLH1 or MSH2 was tested against specific histopathological meningioma subtype or World Health Organization grade. However, genetic changes in DVL3 were strongly associated with anaplastic histology of meningioma (χ Show less