Discovery and Optimization of Potent, Cell-Active Pyrazole-Based Inhibitors of Lactate Dehydrogenase (LDH)

Abstract

We report the discovery and medicinal chemistry optimization of a novel series of pyrazole-based inhibitors of human lactate dehydrogenase (LDH). Utilization of a quantitative high-throughput screening paradigm facilitated hit identification while structure-based design and multi-parameter optimization enabled the development of compounds with potent enzymatic and cell-based inhibition of LDH enzymatic activity. Lead compounds such as 63 exhibit low nM inhibition of both LDHA and LDHB, sub-micromolar inhibition of lactate production and inhibition of glycolysis in MiaPaCa2 pancreatic cancer and A673 sarcoma cells. Moreover, robust target engagement of LDHA by lead compounds was demonstrated using the Cellular Thermal Shift Assay (CETSA) and drug-target residence time was determined via SPR. Analysis of these data suggests that drug-target residence time (off-rate) may be an important attribute to consider for obtaining potent cell-based inhibition of this cancer metabolism target.

The mitochondrial HSP90 paralog TRAP1 forms an OXPHOS-regulated tetramer and is involved in mitochondrial metabolic homeostasis

“…Following preincubation, basal OCR or ECAR were determined before recording mitochondrial stress test profiles by sequential injection of oligomycin, carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), and rotenone with antimycin A in combination. For LDHi experiments, the LDHi (developed by the National Cancer Institute Experimental Therapeutics (NExT) Program) [63,64] was injected first followed by an injection of oligomycin, rotenone, and antimycin in combination to completely inhibit mitochondrial respiration.…”

The mitochondrial HSP90 paralog TRAP1 forms an OXPHOS-regulated tetramer and is involved in maintaining mitochondrial metabolic homeostasis

“…Following preincubation, basal OCR or ECAR were determined before recording mitochondrial stress test profiles by sequential injection of oligomycin, carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) and rotenone with antimycin in combination. For LDHi experiments, the LDHi (developed by the National Cancer Institute Experimental Therapeutics (NExT) Program) [62, 63] was injected first followed by an injection of oligomycin, rotenone and antimycin in combination to completely inhibit mitochondrial respiration.…”

Identifying the Naphthalene-Based Compound 3,5-Dihydroxy 2-Napthoic Acid as a Novel Lead Compound for Designing Lactate Dehydrogenase-Specific Antibabesial Drug

“…Owing to the dependence of parasites on glycolysis system for energy generation, these enzymes play crucial roles as potential drug targets for development of anti-parasitic agents (Dunn et al, 1996). Thus far, many compounds have been reported to produce a significant effect on the enzymatic activity of the protozoan LDHs, including gossypol, derivatives or structural analogs of gossypol, oxamic acid, and azole-based compounds (Cameron et al, 2004;Choi et al, 2007;Rai et al, 2017). Therefore, screening and identifying new BmLDH inhibitors would facilitate the discovery of novel treatment strategies.…”