Supplementary Figure S3 from Protein Kinase B (PKB/AKT) Protects IDH-Mutated Glioma from Ferroptosis via Nrf2

Liu, Yang; Chou, Fu-Ju; Lang, Fengchao; Zhang, Meili; Song, Hua; Zhang, Wei; Davis, Dionne L.; Briceno, Nicole J.; Zhang, Yang; Cimino, Patrick J.; Zaghloul, Kareem A.; Gilbert, Mark R.; Armstrong, Terri S.; Yang, Chunzhang

doi:10.1158/1078-0432.22489814.v1

Supplementary Figure S3 from Protein Kinase B (PKB/AKT) Protects IDH-Mutated Glioma from Ferroptosis via Nrf2

journal contribution

posted on 2023-04-01, 00:20 authored by Yang Liu, Fu-Ju Chou, Fengchao Lang, Meili Zhang, Hua Song, Wei Zhang, Dionne L. Davis, Nicole J. Briceno, Yang Zhang, Patrick J. Cimino, Kareem A. Zaghloul, Mark R. Gilbert, Terri S. Armstrong, Chunzhang Yang

(A) Phase contrast images showed the cytotoxicity of TMZ (400 mM)/ipatasertib (Ipa, 2 mM) combination treatment in the brain tumor-initiating cells (BTICs). A ferroptosis inhibitor, Ferrstain-1 (Ferr-1, 5 mM), was used to rescue the ferroptotic cell death. Bar = 100 mM. (B) Representative flow cytometric analysis of live/dead staining in BTICs in response to TMZ/Ipa treatment. (C) Statistical analysis of dead/live cell ratio in BTICs. (D) The limiting dilution assay evaluated the frequency of generating spheres in GSC827 and TSC603 after receiving TMZ/Ipa treatment. **p < 0.01.

History

ARTICLE ABSTRACT

Mutations of the isocitrate dehydrogenase (IDH) gene are common genetic mutations in human malignancies. Increasing evidence indicates that IDH mutations play critical roles in malignant transformation and progression. However, the therapeutic options for IDH-mutated cancers remain limited. In this study, the investigation of patient cohorts revealed that the PI3K/protein kinase B (AKT) signaling pathways were enhanced in IDH-mutated cancer cells. In this study, we investigated the gene expression profile in IDH-mutated cells using RNA sequencing after the depletion of AKT. Gene set enrichment analysis (GSEA) and pathway enrichment analysis were used to discover altered molecular pathways due to AKT depletion. We further investigated the therapeutic effect of the AKT inhibitor, ipatasertib (Ipa), combined with temozolomide (TMZ) in cell lines and preclinical animal models. GSEA and pathway enrichment analysis indicated that the PI3K/AKT pathway significantly correlated with Nrf2-guided gene expression and ferroptosis-related pathways. Mechanistically, AKT suppresses the activity of GSK3β and stabilizes Nrf2. Moreover, inhibition of AKT activity with Ipa synergizes with the genotoxic agent TMZ, leading to overwhelming ferroptotic cell death in IDH-mutated cancer cells. The preclinical animal model confirmed that combining Ipa and TMZ treatment prolonged survival. Our findings highlighted AKT/Nrf2 pathways as a potential synthetic lethality target for IDH-mutated cancers.