RESUMEN
Circulating tumor-derived DNA testing for cancer screening has recently been demonstrated in a prospective study on identification of nasopharyngeal carcinoma (NPC) among 20,174 asymptomatic individuals. Plasma EBV DNA, a marker for NPC, was detected using real-time PCR. While plasma EBV DNA was persistently detectable in 97.1% of the NPCs identified, â¼5% of the general population had transiently detectable plasma EBV DNA. We hypothesized that EBV DNA in plasma of subjects with or without NPC may have different molecular characteristics. We performed target-capture sequencing of plasma EBV DNA and identified differences in the abundance and size profiles of EBV DNA molecules within plasma of NPC and non-NPC subjects. NPC patients had significantly higher amounts of plasma EBV DNA, which showed longer fragment lengths. Cutoff values were established from an exploratory dataset and tested in a validation sample set. Adopting an algorithm that required a sample to concurrently pass cutoffs for EBV DNA counting and size measurements, NPCs were detected at a positive predictive value (PPV) of 19.6%. This represented superior performance compared with the PPV of 11.0% in the prospective screening study, which required participants with an initially detectable plasma EBV DNA result to be retested within 4 weeks. The observed differences in the molecular nature of EBV DNA molecules in plasma of subjects with or without NPC were successfully translated into a sequencing-based test that had a high PPV for NPC screening and achievable through single time-point testing.
Asunto(s)
Carcinoma , ADN Tumoral Circulante/sangre , ADN Viral/sangre , Herpesvirus Humano 4/genética , Neoplasias Nasofaríngeas , Carga Viral/métodos , Adulto , Carcinoma/sangre , Carcinoma/diagnóstico , Estudios de Cohortes , ADN Viral/química , ADN Viral/genética , Femenino , Humanos , Biopsia Líquida/métodos , Masculino , Persona de Mediana Edad , Técnicas de Diagnóstico Molecular/métodos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/sangre , Neoplasias Nasofaríngeas/diagnóstico , Reproducibilidad de los ResultadosAsunto(s)
Metilación de ADN , ADN/sangre , ADN/metabolismo , Edad Gestacional , Estudios de Factibilidad , Humanos , Tamaño de la PartículaRESUMEN
The dual PI3K-mTOR inhibitor BEZ235 was evaluated in preclinical models of nasopharyngeal carcinoma (NPC). The IC50 value of BEZ235 for growth was in the nanomolar range in vitro, induce G1 cycle arrest and apoptosis, and inhibited AKT and mTOR signaling in most NPC cell lines. No synergistic effect was observed when BEZ235 was combined with chemotherapy. BEZ235 increased MAPK activation in vitro but not in vivo. A daily schedule was more effective than a weekly schedule on tumor growth and inhibition of downstream mTOR signaling in vivo. The activity of BEZ235 maybe independent of the PIK3CA amplification and mutation status.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Imidazoles/farmacología , Neoplasias Nasofaríngeas/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Quinolinas/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Animales , Antineoplásicos/farmacología , Carcinoma , Ciclo Celular , Línea Celular Tumoral , Supervivencia Celular , Cisplatino/farmacología , Activación Enzimática , Femenino , Humanos , Concentración 50 Inhibidora , Sistema de Señalización de MAP Quinasas , Ratones , Ratones Desnudos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/genética , Trasplante de Neoplasias , Paclitaxel/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Serina-Treonina Quinasas TOR/antagonistas & inhibidoresRESUMEN
OBJECTIVE: The Janus kinase 2 (JAK2) is important for embryonic primitive hematopoiesis. A gain-of-function JAK2 (JAK2(V617F)) mutation in human is pathogenetically linked to polycythemia vera (PV). In this study, we generated a zebrafish ortholog of human JAK2(V617F) (referred herewith jak2a(V581F)) by site-directed mutagenesis and examined its relevance as a model of human PV. MATERIALS AND METHODS: Zebrafish embryos at one-cell stage were injected with jak2a(V581F) mRNA (200pg/embryo). In some experiments, the embryos were treated with a specific JAK2 inhibitor, TG101209. The effects of jak2a stimulation on hematopoiesis, jak/stat signaling, and erythropoietin signaling were evaluated at 18-somites. RESULTS: Injection with jak2a(V581F) mRNA significantly increased erythropoiesis, as enumerated by flow cytometry based on gfp(+) population in dissociated Tg(gata1:gfp) embryos. The response was reduced by stat5.1 morpholino coinjection (control: 4.37% +/- 0.08%; jak2a(V581F) injected: 5.71% +/- 0.07%, coinjecting jak2a(V581F) mRNA and stat5.1 morpholino: 4.66% +/- 0.13%; p<0.01). jak2a(V581F) mRNA also upregulated gata1 (1.83 +/- 0.08 fold; p=0.005), embryonic alpha-hemoglobin (1.61 +/- 0.12 fold; p=0.049), and beta-hemoglobin gene expression (1.65 +/- 0.13-fold; p=0.026) and increased stat5 phosphorylation. These responses were also ameliorated by stat5.1 morpholino coinjection or treatment with a specific JAK2 inhibitor, TG101209. jak2a(V581F) mRNA significantly reduced erythropoietin gene (0.24 +/- 0.03 fold; p=0.006) and protein expression (control: 0.633+/-0.11; jak2a(V581F) mRNA: 0.222+/-0.07 mIU/mL; p=0.019). CONCLUSION: The zebrafish jak2a(V581F) model shared many features with human PV and might provide us with mechanistic insights of this disease.