Hidalgo BA, Valdés FM

Idioma: Español
Referencias bibliográficas: 44
Paginas: 78-85
Archivo PDF: 156.35 Kb.

RESUMEN

Los telómeros son complejos de ADN y proteínas localizados en los extremos de los cromosomas lineales que ayudan a mantener la estabilidad genómica. En condiciones normales en células somáticas, los telómeros se acortan con cada división celular. Cuando los telómeros alcanzan cierta longitud, la célula entra en un periodo llamado «senescencia». Sin embargo, algunas células pueden escapar de la senescencia; los telómeros de dichas células se siguen acortando hasta que alcanzan una longitud en la cual la célula entra a una etapa llamada «crisis», donde se empieza a presentar inestabilidad cromosómica, lo cual puede llevar a muerte celular. Algunas células logran activar un mecanismo para restablecer la longitud de los telómeros y continuar proliferando. La activación de un método de mantenimiento de telómeros es una característica primordial de las células tumorales. Existen dos mecanismos conocidos para el mantenimiento de telómeros: uno es la reactivación de la enzima telomerasa –el cual es usado por 85% de los cánceres humanos– y el segundo es la activación de la vía alternativa de mantenimiento del largo de los telómeros (ALT) –presente en el 15% de los tumores malignos, en su mayoría sarcomas–. El mecanismo de mantenimiento de telómeros presente en un tumor puede servir como indicador pronóstico o de respuesta al tratamiento. Y en un futuro, como blanco para tratamientos antineoplásicos.

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