BCR-ABL promotes PTEN downregulation in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by the t(9;22) translocation coding for the chimeric protein p210 BCR-ABL. The tumor suppressor PTEN plays a critical role in the pathogenesis of CML chronic phase, through non genomic loss of function mechanisms, such as protein down-regulation and impaired nuclear/cytoplasmic shuttling. Here we demonstrate that BCR-ABL promotes PTEN downregulation through a MEK dependent pathway. Furthermore, we describe a novel not recurrent N212D-PTEN point mutation found in the EM2 blast crisis cell line.