Abstract 1034: Pharmacological GLUT3 salvage augments the efficacy of vitamin C induced TET2 restoration in AML cells

Abstract

Abstract Background and purpose: Vitamin C has been demonstrated to regulate hematopoietic stem cells (HSC) frequencies and leukemogenesis by augmenting and restoring TET2 function, potentially acting as a novel treatment strategy for leukemia. In a previous study (Liu et al, 2020 Br J Cancer), we showed that GLUT3, a major vitamin C transporter in acute myeloid leukemia (AML) cells, was significantly decreased in AML blasts compared with normal hematopoietic cells, which impedes TET2 restoration and promotes leukemia progression. Although GLUT3 could be a potential biomarker to predict the vitamin C treatment efficiency, a remaining question was whether GLUT3 can be a druggable target in AML. In this study, we aim to investigate the therapeutic value of GLUT3 salvage in AML Methods: GLUT3 salvage was conducted on GLUT3 deficient AML cell line OCI-AML3 using GLUT3 overexpression lentivirus transduction or AICAR (an AMPK activator, Phase 3) treatment. The 5hmC DNA dot blotting assay was carried out to explore the TET2 function. The leukemic phenotypes were evaluated using soft agar colony formation assay, migration assay, and invasion assay. Results: To verify if turning on GLUT3 enhances the efficacy of vitamin C treatment, the GLUT3 overexpression lentivirus or empty vector lentivirus was transduced into the OCI-AML3 cell line. The transcription level of SLC2A3 (gene encoded GLUT3) was increased to 8 times in the GLUT3 overexpression cell line. Then, 5hmC DNA dot blotting results showed that GLUT3 overexpression further significantly raised the 5hmC level after 250 µM vitamin C treatment. Consistent with augmentation of TET2 function, turning on GLUT3 with vitamin C treatment alleviated leukemic phenotypes compared with empty vector group. Pharmacological GLUT3 salvage using AICAR 0.5 mM 48 hours could achieve the same effect as lentivirus transduction, in terms of GLUT3 expression level, augmentation of TET2 function, and enhancement of vitamin C anti-leukemic effect. Notably, AICAR treatment only induced GLUT3 expression while showed no effect on GLUT5. Conclusion: GLUT3 salvage could augment the efficacy of vitamin C induced TET2 restoration in AML cells. Pharmacological GLUT3 salvage using AICAR sheds new light on overcoming GLUT3 deficiency in AML. Citation Format: Jun Liu, Suji Min, Seojeong Kim, Daehyeon Gwak, Junshik Hong, Sungsoo Yoon. Pharmacological GLUT3 salvage augments the efficacy of vitamin C induced TET2 restoration in AML cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1034.