Abstract 5826: Molecular mechanism of OLIG2-CDK2 interaction in glioma cells

Abstract

Abstract Oligodendrocyte transcription factor 2 (Olig2) promotes proliferation of normal neural stem/progenitor cells and glioma cells. However, the mechanisms underlying the regulation of Olig2 remain largely unknown. Here we identified Olig2 as a critical phosphorylation target for cyclin-dependent kinase 2 (CDK2). CDK2-mediated Olig2 phosphorylation stabilizes Olig2 protein from proteasomal degradation. Phosphorylated Olig2 binds to the E-Box regions of p27 promoter and represses p27 transcription, which in turn activates CDK2 in positive feedback manner. CDK2-mediated Olig2 phosphorylation promotes cell cycle progression, cell proliferation, and tumorigenesis. Olig2 inhibition disrupted cell cycle control mechanism by decreasing CDK2 and elevating apoptosis-related molecules. Inhibition of CDK2 activity disrupted Olig2-CDK2 interactions and attenuated Olig2 protein stability. In addition, Olig2-high glioma initiating cells are highly sensitive to CDK2 inhibitor treatment, indicating that Olig2 can be a biomarker for personalized treatment for glioblastoma patients with CDK2 inhibitors. Further investigation on these mechanisms may lead to novel targeted therapy on GBMs with high Olig2 expression. Citation Format: Norihiko Saito, Nozomi Hirai, Sho Sato, Yu Hiramoto, Satoshi Fujita, Haruo Nakayama, Morito Hayashi, Takatoshi Sakurai, Satoshi Iwabuchi. Molecular mechanism of OLIG2-CDK2 interaction in glioma cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5826.