New derivatives of 2-deoxy-D-glucose (2-DG) in the therapy of glioblastoma multiforme - preliminary studies

Abstract

Tumor cells preferentially use the glycolysis process as a source of ATP regardless of the availability of oxygen (Warburg effect). GBM cells are particularly dependent on this process. A PET diagnostic test using a fluoro-labeled 2-DG derivative indicates that GBM cells accumulate 2-DG in their interior. Unfortunately, therapeutic use of 2-DG is limited due to insufficient pharmacokinetic parameters of the compound. However, a chemical modification involving the substitution of -OH groups with acetyl groups leads to an increase in 2-DG permeability across the BBB and its concentrations in GBM cells. Based on previous preliminary results using the O-acetylated 2-DG-2deoxy-3,6-di-O-acetyl-D-glucose derivative (WP1122), we assume that the new halogen (2-BG, 2-IG, 2-CG) and acetyl 2-DG derivatives will be highly cytotoxic to GBM cells. In addition, we anticipate the analysis of a new class of 2-DG derivatives, which may be modulated with ethylbutyrate and VPA, may also modulate the activity of HDAC and thus the expression of genes involved in cell apoptosis. The obtained preliminary results on the in vitro model showed that 2-DG decreases the viability of the U87 and U251 cell lines depending on the dose. The IC50 2-DG is for the following lines: U87-0.6mM, 0.5 mM (46,72h), U251-0.7mM, 0.45mM (48,72h). The percentage of apoptotic cells was evaluated by flow cytometry and cell staining with annexinV and PI. The MTT analysis of WP122 showed that the IC50 is in the cells of U87 line-1.5mM, 0.8mM (48,72h), U2511.25mM, 0.8mM (48,72h). The MTT analyzes of the effects of HDIs: NaBt and VPA determined the IC50 for NaBt: U87-1.48mM, 0.95mM (48,72h), U251-2.1mM, 2mM (48,72h); for VPA: U87-6.2mM, 6.0mM (48,72h), U251-5.3mM, 4.2mM (48,72h). Preliminary studies in the analysis of halo-derivatives interaction with hexokinase allowed to develop a model of expression and obtain a recombinant hexokinase protein, which will then be used for crystallographic analyzes.