RESUMO
The Werner syndrome RecQ helicase WRN was identified as a synthetic lethal target in cancer cells with microsatellite instability (MSI) by several genetic screens1-6. Despite advances in treatment with immune checkpoint inhibitors7-10, there is an unmet need in the treatment of MSI cancers11-14. Here we report the structural, biochemical, cellular and pharmacological characterization of the clinical-stage WRN helicase inhibitor HRO761, which was identified through an innovative hit-finding and lead-optimization strategy. HRO761 is a potent, selective, allosteric WRN inhibitor that binds at the interface of the D1 and D2 helicase domains, locking WRN in an inactive conformation. Pharmacological inhibition by HRO761 recapitulated the phenotype observed by WRN genetic suppression, leading to DNA damage and inhibition of tumour cell growth selectively in MSI cells in a p53-independent manner. Moreover, HRO761 led to WRN degradation in MSI cells but not in microsatellite-stable cells. Oral treatment with HRO761 resulted in dose-dependent in vivo DNA damage induction and tumour growth inhibition in MSI cell- and patient-derived xenograft models. These findings represent preclinical pharmacological validation of WRN as a therapeutic target in MSI cancers. A clinical trial with HRO761 (NCT05838768) is ongoing to assess the safety, tolerability and preliminary anti-tumour activity in patients with MSI colorectal cancer and other MSI solid tumours.
Assuntos
Antineoplásicos , Descoberta de Drogas , Inibidores Enzimáticos , Instabilidade de Microssatélites , Neoplasias , Mutações Sintéticas Letais , Helicase da Síndrome de Werner , Animais , Feminino , Humanos , Camundongos , Administração Oral , Regulação Alostérica/efeitos dos fármacos , Antineoplásicos/efeitos adversos , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Ensaios Clínicos como Assunto , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Dano ao DNA/efeitos dos fármacos , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo , Domínios Proteicos , Reprodutibilidade dos Testes , Supressão Genética , Mutações Sintéticas Letais/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Helicase da Síndrome de Werner/antagonistas & inibidores , Helicase da Síndrome de Werner/genética , Helicase da Síndrome de Werner/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Many cancer cells have increased rates of aerobic glycolysis, a phenomenon termed the Warburg effect. In addition, in tumors there is a predominance of expression of the M2 isoform of pyruvate kinase (PKM2). M2 expression was previously shown to be necessary for aerobic glycolysis and to provide a growth advantage to tumors. We report that knockdown of pyruvate kinase in tumor cells leads to a decrease in the levels of pyruvate kinase activity and an increase in the pyruvate kinase substrate phosphoenolpyruvate. However, lactate production from glucose, although reduced, was not fully inhibited. Furthermore, we are unique in reporting increased serine and glycine biosynthesis from both glucose and glutamine following pyruvate kinase knockdown. Although pyruvate kinase knockdown results in modest impairment of proliferation in vitro, in vivo growth of established xenograft tumors is unaffected by PKM2 absence. Our findings indicate that PKM2 is dispensable for tumor maintenance and growth in vivo, suggesting that other metabolic pathways bypass its function.