Quinoline 3-sulfonamides inhibit lactate dehydrogenase A and reverse aerobic glycolysis in cancer cells

Abstract

BackgroundMost normal cells in the presence of oxygen utilize glucose for mitochondrial oxidative phosphorylation. In contrast, many cancer cells rapidly convert glucose to lactate in the cytosol, a process termed aerobic glycolysis. This glycolytic phenotype is enabled by lactate dehydrogenase (LDH), which catalyzes the inter-conversion of pyruvate and lactate. The purpose of this study was to identify and characterize potent and selective inhibitors of LDHA.MethodsHigh throughput screening and lead optimization were used to generate inhibitors of LDHA enzymatic activity. Effects of these inhibitors on metabolism were evaluated using cell-based lactate production, oxygen consumption, and 13C NMR spectroscopy assays. Changes in comprehensive metabolic profile, cell proliferation, and apoptosis were assessed upon compound treatment.Results3-((3-carbamoyl-7-(3,5-dimethylisoxazol-4-yl)-6-methoxyquinolin-4-yl) amino) benzoic acid was identified as an NADH-competitive LDHA inhibitor. Lead optimization yielded molecules with LDHA inhibitory potencies as low as 2 nM and 10 to 80-fold selectivity over LDHB. Molecules in this family rapidly and profoundly inhibited lactate production rates in multiple cancer cell lines including hepatocellular and breast carcinomas. Consistent with selective inhibition of LDHA, the most sensitive breast cancer cell lines to lactate inhibition in hypoxic conditions were cells with low expression of LDHB. Our inhibitors increased rates of oxygen consumption in hepatocellular carcinoma cells at doses up to 3 microM, while higher concentrations directly inhibited mitochondrial function. Analysis of more than 500 metabolites upon LDHA inhibition in Snu398 cells revealed that intracellular concentrations of glycolysis and citric acid cycle intermediates were increased, consistent with enhanced Krebs cycle activity and blockage of cytosolic glycolysis. Treatment with these compounds also potentiated PKM2 activity and promoted apoptosis in Snu398 cells.ConclusionsRapid chemical inhibition of LDHA by these quinoline 3-sulfonamids led to profound metabolic alterations and impaired cell survival in carcinoma cells making it a compelling strategy for treating solid tumors that rely on aerobic glycolysis for survival.

Targeted inhibition of tumor-specific glutaminase diminishes cell-autonomous tumorigenesis

“…To further determine the target specificity of BPTES, we tested the ability of the overexpressed wild-type V5-GLS to decrease the sensitivity of P493 cells to intermediate doses of BPTES, because high target protein levels in cells have been shown to increase the IC 50 of drugs (47). While both P493 and P493 V5-GLS had similarly diminished proliferation at 5 μM BPTES ( Figure 5, E and F), both proliferated rapidly when exposed to DMSO vehicle control.…”

Inhibition of Lactate Dehydrogenase Activity as an Approach to Cancer Therapy

“…While this manuscript was in preparation, researchers from GlaxoSmithKline announced the discovery of quinoline 3-sulfonamides as potent (nanomolar) LDH inhibitors, with good selectivity towards the A isoform [110]. The details of the high throughput screening procedure leading to this discovery are at present unpublished.…”

An update on therapeutic opportunities offered by cancer glycolytic metabolism

“…The main limitation of 34 are unfavorable pharmacokinetic properties, which hamper its use in in vivo experiments. 61 Recent studies of the chemical class of N-hydroxyindole-based LDH-A-inhibitors produced several compounds that inhibit LDH-A in the low micromolar range. [62][63][64][65][66] It should be mentioned that results from surface plasmon resonance experiments carried out by Astra Zeneca on one of these compounds 55 were ambiguous and led the authors to hypothesize the occurrence of significant levels of nonspecific binding.…”