RESUMEN
Background: Gene expression profiling (GEP) studies recognized a prognostic role for tumor microenvironment (TME) in diffuse large B-cell lymphoma (DLBCL), but the routinely adoption of prognostic stromal signatures remains limited. Patients and methods: Here, we applied the computational method CIBERSORT to generate a 1028-gene matrix incorporating signatures of 17 immune and stromal cytotypes. Then, we carried out a deconvolution on publicly available GEP data of 482 untreated DLBCLs to reveal associations between clinical outcomes and proportions of putative tumor-infiltrating cell types. Forty-five genes related to peculiar prognostic cytotypes were selected and their expression digitally quantified by NanoString technology on a validation set of 175 formalin-fixed, paraffin-embedded DLBCLs from two randomized trials. Data from an unsupervised clustering analysis were used to build a model of clustering assignment, whose prognostic value was also assessed on an independent cohort of 40 cases. All tissue samples consisted of pretreatment biopsies of advanced-stage DLBCLs treated by comparable R-CHOP/R-CHOP-like regimens. Results: In silico analysis demonstrated that higher proportion of myofibroblasts (MFs), dendritic cells, and CD4+ T cells correlated with better outcomes and the expression of genes in our panel is associated with a risk of overall and progression-free survival. In a multivariate Cox model, the microenvironment genes retained high prognostic performance independently of the cell-of-origin (COO), and integration of the two prognosticators (COO + TME) improved survival prediction in both validation set and independent cohort. Moreover, the major contribution of MF-related genes to the panel and Gene Set Enrichment Analysis suggested a strong influence of extracellular matrix determinants in DLBCL biology. Conclusions: Our study identified new prognostic categories of DLBCL, providing an easy-to-apply gene panel that powerfully predicts patients' survival. Moreover, owing to its relationship with specific stromal and immune components, the panel may acquire a predictive relevance in clinical trials exploring new drugs with known impact on TME.
Asunto(s)
Linfoma de Células B Grandes Difuso/mortalidad , Transcriptoma/genética , Microambiente Tumoral/genética , Adulto , Anciano , Algoritmos , Biopsia , Análisis por Conglomerados , Estudios de Cohortes , Biología Computacional , Conjuntos de Datos como Asunto , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Masculino , Persona de Mediana Edad , Adhesión en Parafina , Valor Predictivo de las Pruebas , Pronóstico , Supervivencia sin Progresión , Ensayos Clínicos Controlados Aleatorios como Asunto , Reproducibilidad de los Resultados , Análisis de Supervivencia , Adulto JovenAsunto(s)
Citaféresis , Hipopotasemia/fisiopatología , Fibrilación Ventricular/etiología , Donantes de Sangre , Gluconato de Calcio/uso terapéutico , Femenino , Factor Estimulante de Colonias de Granulocitos/farmacología , Hematopoyesis/efectos de los fármacos , Humanos , Hipopotasemia/sangre , Hipopotasemia/tratamiento farmacológico , Hipopotasemia/etiología , Persona de Mediana Edad , Trasplante de Células Madre de Sangre Periférica , Cloruro de Potasio/uso terapéutico , Índice de Severidad de la Enfermedad , Hermanos , Trasplante Homólogo , Resultado del TratamientoRESUMEN
Oxidative stress has been implicated in the cardiovascular complications that affect chronic renal failure patients on hemodialysis, though the physiologically relevant pathways mediating oxidative damage are poorly understood. It is known, however, that hemodialysis activates neutrophils, a well-characterized source of hydrogen peroxide and myeloperoxidase. The phagocyte-derived myeloperoxidase-hydrogen peroxide-chloride system generates hypochlorous acid, which reacts with tyrosine residues of proteins to form 3-chlorotyrosine. To explore the role of activated phagocytes in oxidative stress in chronic renal failure, we used 3-chlorotyrosine as a specific marker of myeloperoxidase activity. Utilizing isotope dilution gas chromatography-mass spectrometry, we compared 3-chlorotyrosine levels in plasma proteins of five patients on chronic hemodialysis therapy with those of age- and sex-matched healthy controls. The oxidized amino acid was present in the plasma proteins of 4 of the hemodialysis patients (3.5 +/- 0.8 micromol per mol tyrosine) but was undetectable in the healthy subjects. Therefore, one pathway for oxidative stress in hemodialysis patients appears to involve hypochlorous acid generated by the myeloperoxidase system of activated phagocytes. We also examined intradialytic 3-chlorotyrosine levels using membranes that activate white blood cells and the alternative pathway of complement. Hemodialysis increased plasma myeloperoxidase and the expression of CD11b/CD18 by circulating phagocytes, but failed to demonstrably increase 3-chlorotyrosine levels. 3-chlorotyrosine was detectable in 12 of 19 samples in total, with significant intrasubject variability. Our observations suggest that oxidants generated by myeloperoxidase contribute to the increased oxidative stress observed in renal-failure patients but do not damage plasma proteins during the hemodialysis procedure itself.