The Potent and Selective AMPK Inhibitor BAY-3827 Shows Strong Efficacy in Androgen-Dependent Prostate Cancer Models

Abstract Background: 5´ adenosine monophosphate-activated kinase (AMPK) is an essential regulator of cellular energy homeostasis which has been associated with different pathologies, including cancer. Precisely defining the role of AMPK in these processes necessitates the availability of a potent and selective inhibitor.Methods: High-throughput screening and subsequent chemical optimization led to the identification of the selective inhibitor BAY-3827. Cell proliferation and mechanistic assays, as well as gene expression analysis and chromatin immunoprecipitation were used to investigate the cellular impact of BAY-3827 and the crosstalk between lipid metabolism and androgen signaling in prostate cancer models. Also, fatty acid turnover was determined by examining lipid droplet formation.Results: BAY-3827 prevented phosphorylation of acetyl-CoA carboxylase 1 and showed strongest anti-proliferative activity in androgen-dependent prostate cancer cell lines. Analysis of genes involved in AMPK signaling revealed that the expression of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR), fatty acid synthase (FASN) and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2 (PFKFB2), all of which are involved in lipid metabolism, was strongly upregulated by androgen in responsive prostate cancer cell lines. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) analysis identified androgen receptor (AR) binding peaks in these genes. BAY-3827 strongly down-regulated the expression of lipase E (LIPE), cAMP-dependent protein kinase type II-beta regulatory subunit (PRKAR2B) and serine-threonine kinase AKT3 in the responsive prostate cancer cell lines. Also, the expression of members of the carnitine palmitoyl-transferase 1 (CPT1) family was inhibited by BAY-3827, and this was paralleled by impaired lipid flux.Conclusions: The availability of the potent and selective inhibitor BAY-3827 will contribute to a better understanding of the biological role of AMPK signaling in cancer, especially in prostate adenocarcinoma.