RESUMO
PURPOSE: Androgen receptor (AR) signaling is important in prostate cancer progression, and therapies that target this pathway have been the mainstay of treatment for advanced disease for over 70 years. Tumors eventually progress despite castration through a number of well-characterized mechanisms; however, little is known about what determines the magnitude of response to short-term pathway inhibition. METHODS: We evaluated a novel combination of AR-targeting therapies (degarelix, abiraterone, and bicalutamide) and noted that the objective patient response to therapy was highly variable. To investigate what was driving treatment resistance in poorly responding patients, as a secondary outcome we comprehensively characterized pre- and post-treatment samples using both whole-genome and RNA sequencing. RESULTS: We find that resistance following short-term treatment differs molecularly from typical progressive castration-resistant disease, associated with transcriptional reprogramming, to a transitional epithelial-to-mesenchymal transition (EMT) phenotype rather than an upregulation of AR signaling. Unexpectedly, tolerance to therapy appears to be the default state, with treatment response correlating with the prevalence of tumor cells deficient for SNAI2, a key regulator of EMT reprogramming. CONCLUSION: We show that EMT characterizes acutely resistant prostate tumors and that deletion of SNAI2, a key transcriptional regulator of EMT, correlates with clinical response.
Assuntos
Antagonistas de Androgênios/administração & dosagem , Antineoplásicos Hormonais/administração & dosagem , Transição Epitelial-Mesenquimal/genética , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Fatores de Transcrição da Família Snail/genética , Idoso , Antagonistas de Androgênios/efeitos adversos , Androstenos , Anilidas , Antineoplásicos Hormonais/efeitos adversos , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Nitrilas , Oligopeptídeos , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Transdução de Sinais , Fatores de Transcrição da Família Snail/deficiência , Compostos de TosilRESUMO
Cancer is fundamentally a genomic disease caused by mutations or rearrangements in the DNA or epigenetic machinery of a patient. An emerging field in cancer treatment targets key aberrations arising from the mutational landscape of an individual patient's disease rather than employing a cancer-wide cytotoxic therapy approach. In prostate cancer in particular, where there is an observed variation in response to standard treatments between patients with disease of a similar pathological stage and grade, mutationdirected treatment may grow to be a viable tool for clinicians to tailor more effective treatments. This review will describe a number of mutations across multiple forms of cancer that have been successfully antagonised by targeted therapeutics including their identification, the development of targeted compounds to combat them and the development of resistance to these therapies. This review will continue to examine these same mutations in the treatment and management of prostate cancer; the prevalence of targetable mutations in prostate cancer, recent clinical trials of targeted-agents and the potential or limitations for their use.
