Abstract Background Diffuse midline gliomas (DMGs) are aggressive paediatric brain tumours with a median survival of less than 12 months. PI3K/AKT pathway activation following treatment drives tumour progression by enhancing both glycolytic activity and oxidative phosphorylation (OXPHOS). The FOXO family (FOXO1/3/4/6), key regulators of cellular homeostasis, are directly modulated by PI3K/AKT pathway. FOXO1/3 loss contributes to pro tumorigenic phenotype, whereas FOXO1/3 activation is mostly linked to cell cycle arrest and apoptosis. Nevertheless, precise roles of FOXO1 and FOXO3 in DMGs remain poorly understood. Methods We used two RNA sequencing data sets including FOXO1 and FOXO3 knockouts with corresponding parental SF8628 DMG cells, and publicly available DMG-patient-derived dataset to investiagate FOXO1/3 roles in pathways linked to metabolism and apoptosis. RNA-seq data were further validated by western blots. Moreover, we used LOM612, a small-molecule AKT/PI3K inhibitor that actively promotes FOXO nuclear translocation, to restore FOXO1/3 functions. Results RNA sequencing results revealed an imbalance in glycolysis and OXPHOS markers, highlighting FOXO1/3 role in metabolic regulation in cancer cells. Treatment of DMG cells with the LOM612 restored FOXO1/3 nuclear localisation and concurrently suppressed MYC expression. Notably, patient-derived RNA-sequencing data showed elevated levels of proteins involved in active FOXO1/3 sequestration from the nucleus: 14-3-3γ and 14-3-3ζ. High MYC levels were likewise linked to a poor prognosis, underscoring the importance of 14-3-3–mediated FOXO1/3 sequestration and MYC-driven oncogenic signalling in DMGs. Altogether, these data point to a central PI3K-FOXO-MYC axis. Conclusion Taken together, these findings identify the cytoplasmic sequestration of FOXO1/3 by 14-3-3 proteins as a key mechanism underlying DMG resilience. We propose targeting the PI3K-FOXO axis with LOM612 to reactivate FOXO1/3 mediated tumor-suppressive functions. This approach may effectively disrupt the metabolic and MYC-driven pathways that support tumor survival.
Mazza et al. (Fri,) studied this question.