Abstract 4221: Characterization and comparison of hypoxia inducing factors on tumor growth and metastasis in 2D and 3D tumor models

Abstract The monocarboxylic acid transporter 4 (Mct-4), a downstream biomarker of hypoxia inducing factor (HIF) -1α, is involved in the cellular response to hypoxia, as indicated by the hypoxic response element in its promoter region. Using a tumorsphere assay as an in vitro 3-dimensional (3D) model generated using 384-well ultra-low attachment (ULA) plates for cell proliferation analysis using a plate-based image cytometer, we identify a hypoxic response in the tumorsphere model that is distinct from that of cells grown under 2-dimensional (2D) normoxic conditions and demonstrate a key role for Mct-4 in enabling 3D growth. The tumorsphere model yields evidence of an essential role for Mct-4 in multiple cell lines which were genetically modified to underexpress and overexpress Mct-4, evidence not apparent in a standard 2D model of growth in the same cell lines. In addition, we identify the effects of overexpressing Mct-4 in cancer cell migration using a transwell chamber assay. We also show that the response to hypoxia may be circumvented by transfection with a CMV promoter driven Mct-4, which confers constitutive 3D growth, wherein tumorsphere growth inhibition by small molecule HIF-1α inhibitors is mitigated. Finally, we demonstrate quantifiable gene/protein expression differences between 2D and 3D cancer models based on the normoxic and hypoxic conditions. Therefore, the tumorsphere 3D model generated using 384-well ULA plates in combination with high-throughput image cytometer is demonstrated to provide a convenient, robust, and reproducible tool and method for the elucidation of mechanisms of action underlying tumor growth and migration in the hypoxic tumor microenvironment. Citation Format: James McDonald, Leo Li-Ying Chan, Sarah Kessel, Bo Lin, Paul Weingarten. Characterization and comparison of hypoxia inducing factors on tumor growth and metastasis in 2D and 3D tumor models abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 4221.