RESUMO
New targeted approaches to ovarian clear cell carcinomas (OCCC) are needed, given the limited treatment options in this disease and the poor response to standard chemotherapy. Using a series of high-throughput cell-based drug screens in OCCC tumor cell models, we have identified a synthetic lethal (SL) interaction between the kinase inhibitor dasatinib and a key driver in OCCC, ARID1A mutation. Imposing ARID1A deficiency upon a variety of human or mouse cells induced dasatinib sensitivity, both in vitro and in vivo, suggesting that this is a robust synthetic lethal interaction. The sensitivity of ARID1A-deficient cells to dasatinib was associated with G1-S cell-cycle arrest and was dependent upon both p21 and Rb. Using focused siRNA screens and kinase profiling, we showed that ARID1A-mutant OCCC tumor cells are addicted to the dasatinib target YES1. This suggests that dasatinib merits investigation for the treatment of patients with ARID1A-mutant OCCC. Mol Cancer Ther; 15(7); 1472-84. ©2016 AACR.
Assuntos
Adenocarcinoma de Células Claras/genética , Antineoplásicos/farmacologia , Dasatinibe/farmacologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Neoplasias Ovarianas/genética , Inibidores de Proteínas Quinases/farmacologia , Mutações Sintéticas Letais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Adenocarcinoma de Células Claras/tratamento farmacológico , Adenocarcinoma de Células Claras/patologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Perfilação da Expressão Gênica , Humanos , Camundongos , Terapia de Alvo Molecular , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Drugs that inhibit insulin-like growth factor 1 (IGFI) receptor IGFIR were encouraging in early trials, but predictive biomarkers were lacking and the drugs provided insufficient benefit in unselected patients. In this study, we used genetic screening and downstream validation to identify the WNT pathway element DVL3 as a mediator of resistance to IGFIR inhibition. Sensitivity to IGFIR inhibition was enhanced specifically in vitro and in vivo by genetic or pharmacologic blockade of DVL3. In breast and prostate cancer cells, sensitization tracked with enhanced MEK-ERK activation and relied upon MEK activity and DVL3 expression. Mechanistic investigations showed that DVL3 is present in an adaptor complex that links IGFIR to RAS, which includes Shc, growth factor receptor-bound-2 (Grb2), son-of-sevenless (SOS), and the tumor suppressor DAB2. Dual DVL and DAB2 blockade synergized in activating ERKs and sensitizing cells to IGFIR inhibition, suggesting a nonredundant role for DVL3 in the Shc-Grb2-SOS complex. Clinically, tumors that responded to IGFIR inhibition contained relatively lower levels of DVL3 protein than resistant tumors, and DVL3 levels in tumors correlated inversely with progression-free survival in patients treated with IGFIR antibodies. Because IGFIR does not contain activating mutations analogous to EGFR variants associated with response to EGFR inhibitors, we suggest that IGF signaling achieves an equivalent integration at the postreceptor level through adaptor protein complexes, influencing cellular dependence on the IGF axis and identifying a patient population with potential to benefit from IGFIR inhibition.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Resistencia a Medicamentos Antineoplásicos , Fator de Crescimento Insulin-Like I/fisiologia , Fosfoproteínas/fisiologia , Receptor IGF Tipo 1/antagonistas & inibidores , Proteínas ras/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Proteínas Desgrenhadas , Expressão Gênica , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Concentração Inibidora 50 , Isoxazóis/farmacologia , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Pirimidinas/farmacologia , Receptor IGF Tipo 1/metabolismo , Proteínas Wnt/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PARP inhibitors have been proposed as a potential targeted therapy for patients with triple-negative (ER-, PR-, HER2-negative) breast cancers. However, it is as yet unclear as to whether single agent or combination therapy using PARP inhibitors would be most beneficial. To better understand the mechanisms that determine the response to PARP inhibitors, we investigated whether enzymes involved in metabolism of the PARP substrate, ß-NAD(+) , might alter the response to a clinical PARP inhibitor. Using an olaparib sensitization screen in a triple-negative (TN) breast cancer model, we identified nicotinamide phosphoribosyltransferase (NAMPT) as a non-redundant modifier of olaparib response. NAMPT is a rate-limiting enzyme involved in the generation of the PARP substrate ß-NAD(+) and the suppression of ß-NAD(+) levels by NAMPT inhibition most likely explains these observations. Importantly, the combination of a NAMPT small molecule inhibitor, FK866, with olaparib inhibited TN breast tumour growth in vivo to a greater extent than either single agent alone suggesting that assessing NAMPT/PARP inhibitor combinations for the treatment of TN breast cancer may be warranted.
