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Assessing Somatic Hypermutation in Ramos B Cells after Overexpression or Knockdown of Specific Genes
Published on: November 1, 2011
La hipermutación de múltiples proto-oncogenes en los linfomas difusos de células grandes difusos de células B
L Pasqualucci1, P Neumeister, T Goossens
1Institute for Cancer Genetics and the Department of Pathology, Columbia University, New York, New York 10032, USA.
Nature
|July 19, 2001
Resumen
La actividad de hipermutación aberrante se dirige a genes clave en los linfomas difusos de células grandes (DLCL), lo que genera inestabilidad en todo el genoma. Esta disfunción de la hipermutación somática puede ser un importante contribuyente a la linfomagénesis en estos tumores derivados del centro germinal.
Área de la Ciencia:
- Oncología Oncología.
- Genética La genética.
- Biología Molecular Biología Molecular
Sus antecedentes:
- La inestabilidad genómica es un sello distintivo del cáncer, contribuyendo a la tumorigénesis a través de mecanismos como la segregación de cromosomas defectuosos o la reparación del desajuste del ADN.
- Los linfomas de células B a menudo exhiben translocaciones cromosómicas, pero los mecanismos subyacentes de la inestabilidad de todo el genoma durante la linfomagénesis siguen sin estar claros.
- La hipermutación somática normalmente ocurre en los genes de la región variable de inmunoglobulina (V) de las células B del centro germinal durante el desarrollo de las células B.
Objetivo del estudio:
- Investigar los mecanismos de inestabilidad de todo el genoma en los linfomas difusos de células grandes (DLCL).
- Para identificar posibles disfunciones en los procesos de hipermutación somática que contribuyen a la linfomagénesis.
- Explorar la relación entre la hipermutación aberrante y las translocaciones cromosómicas en DLCLs.
Principales métodos:
- Análisis de los patrones de mutación en proto-oncogenes (PIM1, MYC, RhoH/TTF, PAX5) en muestras de DLCL.
- Comparación de los perfiles de mutación en DLCL con los de las células B normales del centro germinal y otros linfomas.
- Evaluación de la relación entre los sitios de hipermutación y los puntos de ruptura de la translocación cromosómica.
Principales resultados:
- Se identificó actividad de hipermutación aberrante en más del 50% de las DLCL, dirigida a múltiples proto-oncogenes.
- Estas mutaciones, distintas de la hipermutación de la región V, no se encontraron en las células B normales del centro germinal u otros linfomas derivados del centro germinal.
- Los genes afectados eran susceptibles a translocaciones cromosómicas en las mismas regiones, lo que sugiere que la hipermutación puede generar rupturas de doble cadena que conducen a translocaciones.
Conclusiones:
- Un mal funcionamiento de la hipermutación somática dirigida a múltiples loci de genes, incluidos los protooncogenes, se asocia con las DLCL.
- Este proceso de hipermutación aberrante puede ser un conductor significativo de la linfomagénesis al mutar genes críticos y potencialmente inducir translocaciones cromosómicas.
- Los hallazgos destacan un nuevo mecanismo que contribuye a la inestabilidad genómica observada en los linfomas difusos de células grandes.
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