Expression of Epithelial-Mesenchymal Transition-Related Genes in Primary Brain Tumors

Gliomas are the most common malignant primary brain tumors in adults. Meningiomas, on the other hand, are benign primary brain tumors treated by surgical resection. Epithelial-to-mesenchymal transition (EMT), stemness, and leader behavior are among the most important complex processes contributing to tumor progression and aggressiveness. Thus, the evaluation of molecular targets involved in the EMT processes in primary brain tumors can help elucidate the molecular mechanisms underlying glioma aggressiveness, ultimately identifying potential areas for further research.

We conducted expression analysis of zinc finger E-box homeobox 1 (ZEB1), Sry-related HMG box (SOX2), and p21 in 31 glioma (15 glioblastoma [GBM] and 16 non-GBM) and 44 meningioma samples using quantitative real-time PCR. We also compared expression levels between glioma and meningioma, as well as between GBM and non-GBM tumor samples.

The expression levels of SOX2 and ZEB1 showed a significant increase in gliomas compared to meningiomas (p = 0.016 and 0.017, respectively). However, p21 did not reveal any significant difference in expression between the two groups. Notably, p21 was the only gene that exhibited a significant increase in expression in GBM samples compared to non-GBM samples, with a p value of 0.027.

Our results suggest that SOX2 and ZEB1 expression levels have a significant role in glioma progression. Interestingly, based on the elevated p21 expression level in the GBM, we also suggest that aggressive tumor features arise from distinct molecular mechanisms depending on tumor subtype, not a single universal pathway.