Abstract 114: TG02 induces cell cycle arrest in glioblastoma

Abstract

Abstract Dysregulated cell cycle contributes to the limitless replicative potential of cancer cells. The cyclin-dependent kinases (CDKs) and cyclins, the CDK-regulatory proteins are the key cell cycle machinery and can be targets for cancer therapy. TG02, a pyrimidine-based multi-kinase inhibitor has an anti-glioma effect which was demonstrated by our previous studies. An in vitro kinase spectrum assay of TG02 demonstrated inhibitory effects in several CDKs at the nanomolar level. To further investigate the molecular mechanisms of TG02-induced cell cycle regulation in glioma, a cell cycle analysis was performed by flow cytometry using the Click-It Edu Flow Cytometric Assay Kit in GSC923 and U251 cell lines, a human stem-like cell and patient derived cell line, respectively. Protein expression of CDKs and cyclins was tested by Western blotting. RNAseq analysis using Next Generation Sequencing was performed (only GSC923) and followed by a supervised hierarchical clustering analysis of cell cycle pathways that were derived from Qiangen’s Ingenuity Pathway Analysis (IPA). Our results showed that TG02 treatment results in G2/M-phase arrest in glioma cell lines. The protein expression of CDK1, CDK2, cyclin A2 and cyclinB1 are downregulated in both TG02 treated cell lines. Additionally, RNAseq analysis revealed downregulation of cyclins A2, B1 and B2 and significant irregulation in mRNA expression of G2/M checkpoint and spindle formation proteins, indicating G2 checkpoint and mitosis progression are also affected by TG02. Taken together, we demonstrated that TG02 induced cell cycle G2/M arrest through downregulating CDK and cyclin expression signaling in the preclinical models of glioblastoma. These findings strongly support the further investigation of TG02 as a potential therapy for malignant gliomas. <!–EndFragment–> Citation Format: Yu-Ting Su, Robert Chen, Hallie Lappin, Herui Wang, Dragan Maric, Orieta Celiku, Aiguo Li, Mark R. Gilbert, Jing Wu. TG02 induces cell cycle arrest in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 114. doi:10.1158/1538-7445.AM2017-114