RESUMEN
In pediatric acute lymphoblastic leukemia (ALL), mutations/deletions affecting the TP53 gene are rare at diagnosis. However, at relapse about 12% of patients show TP53 aberrations, which are predictive of a very poor outcome. Since p53-mediated apoptosis is an endpoint for many cytotoxic drugs, loss of p53 function frequently leads to therapy failure. In this study we show that CRISPR/Cas9-induced loss of TP53 drives resistance to a large majority of drugs used to treat relapsed ALL, including novel agents such as inotuzumab ozogamicin. Using a high-throughput drug screen, we identified the histone deacetylase inhibitor romidepsin as a potent sensitizer of drug responsiveness, improving sensitivity to all chemotherapies tested. In addition, romidepsin improved the response to cytarabine in TP53-deleted ALL cells in vivo. Together, these results indicate that the histone deacetylase inhibitor romidepsin can improve the efficacy of salvage therapies for relapsed TP53-mutated leukemia. Since romidepsin has been approved for clinical use in some adult malignancies, these findings may be rapidly translated to clinical practice.
Asunto(s)
Depsipéptidos , Inhibidores de Histona Desacetilasas , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Proteína p53 Supresora de Tumor , Humanos , Inhibidores de Histona Desacetilasas/uso terapéutico , Inhibidores de Histona Desacetilasas/farmacología , Proteína p53 Supresora de Tumor/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Depsipéptidos/farmacología , Depsipéptidos/uso terapéutico , Ratones , Animales , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Sistemas CRISPR-Cas , Ensayos Antitumor por Modelo de Xenoinjerto , Sinergismo FarmacológicoRESUMEN
Cell-free DNA (cfDNA) can be isolated and sequenced from blood and/or urine of cancer patients. Conventional short-read sequencing lacks deployability and speed and can be biased for short cfDNA fragments. Here, we demonstrate that with Oxford Nanopore Technologies (ONT) sequencing we can achieve delivery of genomic and fragmentomic data from liquid biopsies. Copy number aberrations and cfDNA fragmentation patterns can be determined in less than 24 h from sample collection. The tumor-derived cfDNA fraction calculated from plasma of lung cancer patients and urine of bladder cancer patients was highly correlated (R = 0.98) with the tumor fraction calculated from short-read sequencing of the same samples. cfDNA size profile, fragmentation patterns, fragment-end composition, and nucleosome profiling near transcription start sites in plasma and urine exhibited the typical cfDNA features. Additionally, a high proportion of long tumor-derived cfDNA fragments (> 300 bp) are recovered in plasma and urine using ONT sequencing. ONT sequencing is a cost-effective, fast, and deployable approach for obtaining genomic and fragmentomic results from liquid biopsies, allowing the analysis of previously understudied cfDNA populations.