Page 166 - Molecular features of low-grade developmental brain tumours

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Figure 4. miR-519d and miR-4758 target mRNA expression and the regulation of cell cycle in cell culture. Panels A-C: Relative expression of CDKN1A (A), CDKN1B (B) and PTEN (C) after transfection of LGG2 cell line for 24 hours with lipofectamine (n=5), miR-519d mimic (n=4), miR-4758 mimic (n=5) or miR- 519d mimic co-transfected with miR-4758 mimic (n=5). Panel D: The S phase of cell cycle progression after transfection with lipofectamine (n=7), miR-519d (n=7), miR-4758 (n=8) and miR-519d (n=7) co- transfected with miR-4758 in LGG2. miR-519d transfected LGG2 cells displayed an increased S phase compared to the negative control. miR-4758 transfected cultures displayed no alteration in S phase. Co-transfection of miR-519d and miR-4758 was able to mimic the response of the negative control. The error bars represent SEM; statistical significance: *p < 0.05; **p < 0.01, ***p < 0.001, Kruskal-Wallis test
followed by Mann-Whitney U test.
Discussion
In this study, we showed that miR-519d and miR-4758 are specifically upregulated in GGs compared to control tissue, DNTs and other gliomas. In addition, we showed that the PI3K/ AKT3/P21 pathway was deregulated in GGs. Importantly, we observed a downregulation of CDKN1A (P21) and an increase in cell proliferation after miR-519d overexpression in an astrocytic cell line, whereas co-transfection with miR-4758 counteracted this effect, suggesting an oncogenic function of miR-519d.
GNTs represent a major cause of medically intractable epilepsy in young patients, however their underlying biology remains to be fully investigated. The 2016 revised WHO