Design and Biological Evaluation of ALKBH2 and ALKBH5 Inhibitors as Adjuvants to Temozolomide-based Glioblastoma Treatment.

Abstract This study reports the design, synthesis, and biological evaluation of novel inhibitors targeting the epigenetic enzymes ALKBH2 and ALKBH5 as potential adjuvants to temozolomide therapy in glioblastoma. Given their critical role in DNA/RNA demethylation, tumor progression, and drug resistance, their inhibition represents a promising therapeutic strategy. Building on the previously identified lead compound MV1035, we employed structure-based drug design to develop new derivatives, including a second-generation series incorporating a fumarate hydrazide moiety to enhance binding affinity through Biology 2026, 15, 1371 https://doi.org/10.3390/biology15161371 Biology 2026, 15, 1371 2 of 32 interaction with both substrate- and cofactor-binding sites. Molecular docking studies predicted significantly improved binding for a set of new compounds but, due to multiple synthetic drawbacks, only a subset of the designed series was synthesized and evaluated biologically. MV3030 emerged as the most promising candidate. MV3030 demonstrated an inhibitory effect on ALKBH2 comparable to MV1035, also showing a more moderate inhibitory effect on ALKBH5. Notably, it exhibited intrinsic cytotoxicity in U87-MG cells and patient-derived glioma stem cells, whereas normal astrocytes exhibited markedly higher resistance to the treatment. Furthermore, MV3030 enhanced temozolomide efficacy and displayed favorable blood–brain barrier permeability both in silico and in vitro. Moreover, MV3030 modulated the FoxM1/Wnt/β-catenin axis. Overall, these findings identify MV3030 as a promising compound with the potential to overcome temozolomide resistance and improve glioblastoma treatment.