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Fbxw7/Cdc4 es un gen supresor de tumores dependiente de p53, haploinsufficiente y dependiente de p53
Jian-Hua Mao1, Jesus Perez-Losada, Di Wu
1Cancer Research Institute, University of California at San Francisco, 2340 Sutter Street, San Francisco, California 94143, USA.
Nature
|December 14, 2004
Resumen
El gen Fbxw7 actúa como supresor tumoral, y su pérdida contribuye al desarrollo de cáncer, particularmente en ratones con deficiencia de p53. Este gen supresor de tumores haploinsufficiente es suficiente.
Área de la Ciencia:
- Oncología Oncología.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- El gen FBXW7/hCDC4 codifica una ubiquitina ligasa crucial para la estabilidad cromosómica.
- La tumorigénesis es un proceso complejo que implica mutaciones genéticas y la pérdida de genes supresores de tumores.
- La vía p53 es un regulador crítico de la detención del ciclo celular y la apoptosis en respuesta al daño del ADN.
Objetivo del estudio:
- Para identificar genes supresores de tumores dependientes de p53 involucrados en la tumorigénesis utilizando una pantalla genética de mamíferos.
- Investigar el papel del gen Fbxw7 del ratón en el desarrollo del cáncer y su relación con p53.3.
- Comprender los mecanismos moleculares por los cuales la pérdida de Fbxw7 contribuye a la inestabilidad genética y la formación de tumores.
Principales métodos:
- Prueba genética de mamíferos para genes dependientes de p53 en linfomas inducidos por radiación.
- Pérdida de heterocigosidad y análisis de la tasa de mutación del gen Fbxw7 en ratones p53+/- y p53-/-.
- Análisis del espectro tumoral en ratones Fbxw7+/- y ratones con deficiencia de p53.
- Análisis de los niveles de proteínas (Aurora-A quinasa, c-Jun, Notch4, ciclina E) en fibroblastos embrionarios de ratón con deficiencia de Fbxw7 y células de tipo salvaje con knockdown de Fbxw7.
Principales resultados:
- El gen Fbxw7 del ratón fue identificado como un supresor tumoral dependiente de p53.
- Se observó una pérdida frecuente de heterocigosidad y mutaciones en Fbxw7 en linfomas inducidos por radiación de ratones p53+/- .
- La insuficiencia de haploínas Fbxw7 aumentó la susceptibilidad a la tumorigénesis inducida por radiación.
- La pérdida de Fbxw7 en ratones con deficiencia de p53 condujo a un espectro más amplio de tumores epiteliales (pulmón, hígado, ovario).
- La deficiencia de Fbxw7 dio lugar a niveles elevados de Aurora-A quinasa, c-Jun y Notch4.
Conclusiones:
- Fbxw7 funciona como un gen supresor de tumores haploinsufficiente de una manera dependiente de p53.
- La pérdida de Fbxw7 contribuye a la inestabilidad genética, potencialmente a través de la activación de la Aurora-A quinasa.
- Estos hallazgos proporcionan una justificación para la aparición temprana de mutaciones Fbxw7 en cánceres humanos.
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