Abstract 5023: Disruption of Monocarboxylate transporter-4 Basigin interaction as an effective strategy to inhibit hypoxic response, tumor growth and vascularization, and stem cell phenotype in human glioblastoma in vitro and in vivo

Monocarboxylate transporters, constitute a family (SLC16) of proton-linked plasma membrane transporters that carry molecules containing a single carboxylate group across biological membranes. Basigin (CD147), is involved in many physiological functions during early stages of development and in cancer. Basigin has been shown to be required for functional plasma membrane expression of Monocarboxylate transporter-1 and Monocarboxylate transporter-4. Using a cell-based screening assay, we identified acriflavine, a small molecule that inhibits the binding between Basigin and Monocarboxylate transporters in vitro and in vivo. Surface Plasmon Resonance analysis confirmed direct binding of acriflavine to Basigin’s immunoglobulin extracellular domain with a low binding constant (kD) of 0.16µM. Acriflavine inhibits normoxic growth of glioma stem cells in vitro and this activity is augmented by hypoxia or by expression of oxygen-stable mutant forms of HIF-1α or HIF-2α. Treatment of mice bearing established glioma stem cell-derived xenografts resulted in inhibition of tumor growth. Acriflavine treatment inhibited intratumoral expression of the angiogenic cytokine vascular endothelial growth factor and tumor vascularization. Our work shows that disruption of monocarboxylate transporter binding to Basigin is an effective approach to target glioma stem cells. Citation Format: Raffaella Spina, Dillon M. Voss, Kah Suan Lim, Constance J. Jeffery, Eli E. Bar. Disruption of Monocarboxylate transporter-4 Basigin interaction as an effective strategy to inhibit hypoxic response, tumor growth and vascularization, and stem cell phenotype in human glioblastoma in vitro and in vivo [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 5023. doi:10.1158/1538-7445.AM2017-5023