Genome-wide perturbations of Alu expression and Alu-associated post-transcriptional regulations distinguish oligodendroglioma from other gliomas

Alu is a primate-specific repeat element in the human genome and has been increasingly appreciated as a regulatory element in many biological processes. But the appreciation of Alu has been limited in tumorigenesis, especially for brain tumor. To investigate the relevance of Alu to the gliomagenesis, we studied Alu element-associated post-transcriptional processes and the RNA expression of the element by performing RNA-seq for a total of 41 pairs of neurotypical and diverse glioma brain tissues. We find that A-to-I editing and circular RNA levels, as well as Alu RNA expression, are decreased overall in gliomas, compared to normal tissue. Interestingly, grade 2 oligodendrogliomas are least affected in A-to-I editing and circular RNA levels among gliomas, whereas they have a higher proportion of down-regulated Alu subfamilies, compared to the other gliomas. These findings collectively imply a unique pattern of Alu-associated transcriptomes in grade 2 oligodendroglioma, providing an insight to gliomagenesis from the perspective of an evolutionary genetic element. Taeyoung Hwang et al. evaluate the relevance of Alu repeat elements to gliomagenesis using transcriptomic data from 41 pairs of neurotypical and diverse glioma brain tissues. Their results reveal that grade 2 oligodendroglioma differs from other gliomas with a higher proportion of perturbed Alu subfamilies and the minimally-affected overall A-to-I editing and circular RNA levels, providing further insight into gliomagenesis.

Automated summary

The study reveals that Alu element-associated post-transcriptional processes and RNA expression are decreased in gliomas, with grade 2 oligodendrogliomas showing the least perturbation in A-to-I editing and circular RNA levels. This provides further insight into gliomagenesis from the perspective of Alu repeat elements.