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Regulación negativa de la supervivencia celular dependiente de PKB/Akt por el supresor de tumores PTEN
V Stambolic1, A Suzuki, J L de la Pompa
1Amgen Institute, and Department of Medical Biophysics, University of Toronto, Ontario, Canada.
Cell
|October 20, 1998
Resumen
PTEN actúa como un supresor tumoral mediante la regulación de la supervivencia celular. Este estudio muestra que el PTEN regula negativamente el PI3.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Oncología Oncología.
- Biología celular Biología celular.
Sus antecedentes:
- PTEN (homólogo de la fosfatasa y la tensina) es un supresor de tumores conocido.
- Su homología con la proteína tirosina fosfatasas y la tensina sugiere un papel en la regulación celular.
- La desregulación de la proliferación celular y las vías de supervivencia es un sello distintivo del cáncer.
Objetivo del estudio:
- Para investigar el papel de PTEN en la regulación de la proliferación celular y la apoptosis.
- Aclarar los mecanismos moleculares por los cuales el PTEN funciona como supresor de tumores.
- Examinar la relación entre PTEN y la vía de señalización PI3K/Akt.
Principales métodos:
- Utilizados embriones de ratón mutantes en mPTEN e inmortalizados fibroblastos embrionarios de ratón.
- Se evaluó la proliferación celular y la sensibilidad a la apoptosis.
- Se midió la actividad y fosforilación de la proteína quinasa B/Akt (PKB/Akt).
- Se investigó la actividad enzimática de PTEN sobre el fosfatidilinositol (3,4,5) y el trisfosfato in vitro.
Principales resultados:
- Los embriones mutantes en mPTEN mostraron un aumento de la proliferación.
- Las células con deficiencia de mPTEN mostraron una disminución de la sensibilidad a la apoptosis y una actividad elevada de PKB/Akt.
- La expresión exógena de PTEN restauró la sensibilidad a la apoptosis y normalizó la fosforilación PKB/Akt.
- Se demostró que el PTEN regula negativamente los niveles intracelulares de fosfatidilinositol (3,4,5) trifosfato y lo desfosforila in vitro.
Conclusiones:
- PTEN juega un papel crítico en la supresión de la formación de tumores.
- PTEN ejerce su función supresora del tumor mediante la regulación negativa de la vía de señalización PI3K/PKB/Akt.
- Esta vía es crucial para controlar la supervivencia y la proliferación celular.
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