ABSTRACT
Clinical and molecular heterogeneity are hallmarks of chronic lymphocytic leukemia (CLL), a neoplasm characterized by accumulation of mature and clonal long-lived CD5 + B-lymphocytes. Mutational status of the IgHV gene of leukemic clones is a powerful prognostic tool in CLL, and it is well established that unmutated CLLs (U-CLLs) have worse evolution than mutated cases. Nevertheless, progression and treatment requirement of patients can evolve independently from the mutational status. Microenvironment signaling or epigenetic changes partially explain this different behavior. Thus, we think that detailed characterization of the miRNAs landscape from patients with different clinical evolution could facilitate the understanding of this heterogeneity. Since miRNAs are key players in leukemia pathogenesis and evolution, we aim to better characterize different CLL behaviors by comparing the miRNome of clinically progressive U-CLLs vs. stable U-CLLs. Our data show up-regulation of miR-26b-5p, miR-106b-5p, and miR-142-5p in progressive cases and indicate a key role for miR-26b-5p during CLL progression. Specifically, up-regulation of miR-26b-5p in CLL cells blocks TGF-ß/SMAD pathway by down-modulation of SMAD-4, resulting in lower expression of p21-Cip1 kinase inhibitor and higher expression of c-Myc oncogene. This work describes a new molecular mechanism linking CLL progression with TGF-ß modulation and proposes an alternative strategy to explore in CLL therapy.
ABSTRACT
Resumen: El síndrome hemofagocítico es una enfermedad infrecuente y grave caracterizada por un estado de hiperinflamación sistémica con sobreproducción de citocinas. Puede responder a causas genéticas (primario) o desencadenarse por infecciones, fármacos, neoplasias o enfermedades autoinmunes. Existen criterios diagnósticos establecidos. El tratamiento consiste en el bloqueo de la respuesta inflamatoria sistémica, asociado al tratamiento de la causa desencadenante cuando se halla. La mortalidad es alta y usualmente está en relación a la causa que gatilla el fenómeno. Se presenta un caso de sindrome hemofagocítico en paciente infectada por el virus de la inmunodeficiencia humana.
Abstract: Hemophagocytic syndrome is a rare and serious disease characterized by a state of systemic hyperinflammation with overproduction of cytokines. Can respond to genetic causes (primary) or be triggered by infections, drugs, tumors or autoimmune diseases. There are established diagnostic criteria. Treatment consists in blocking the inflammatory response associated with the treatment of the underlying cause when it is. Mortality is high and usually is related to the cause that triggers the phenomenon. We report a case of hemophagocytic syndrome in HIV-infected patient.