Deploying the high-throughput virtual screening (HTVS) approach for the identification of new lactate dehydrogenase (LDH) inhibitors with anticancer assets

The tumor cells frequently rely on glycolysis to produce adenosine 5'-triphosphate (ATP), even when sufficient oxygen is available to allow oxidative phosphorylation (the Warburg effect). In these malignancies, the breakdown of glucose to pyruvate, instead of reaching the mitochondria, is transformed to lactate by an enzyme called lactate dehydrogenase (LDH) and then expelled by the cells, further fuelling the tumour microenvironment (TME). LDH facilitates the translation of pyruvate to lactate, hence replenishing the required NAD + equivalents for the ongoing glycolysis process. Having a pivotal role in cancer cells' prognosis and survival, and affecting the TME. To date, no inhibitors have yet been approved against the LDH. However, numerous clinical trials are ongoing, and results are yet to be awaited. Considering the existing gap, we present herein a high-throughput virtual screening (HTVS) approach to identify new compounds that effectively inhibit LDH activity. We generated the pharmacophore model based on 28 LDH enzyme inhibitors from previous literature. The model was used to screen 500,000 ligands in addition to their molecular docking and drug-likeness filtering. The analysis led to the identification of 5 hits, which were further subjected to the MD simulations. Further considering the outcome of molecular dynamics results, we selected ligands 15 and 422 to corroborate their anticancer potential via inhibiting the LDH enzyme. The biological validation revealed that both ligands, 15 and 422, possess IC₅₀ values of 147.34 and 206.35 nM, respectively, against LDH. The anticancer potential analysis of DU-145 and PC-3 also established their anticancer properties, and both compounds were found to marginally elevate oxidative stress, change mitochondrial membrane potential, and induce apoptosis in DU-145 cells.