Increase in mutant frequencies in mice expressing the BCR-ABL activated tyrosine kinase.

The acquisition of the Philadelphia (Ph) chromosome (or BCR-ABL translocation) represents a detrimental pathophysiological event in humans. The activated tyrosine kinases, which are produced by this translocation, are associated with fatal hematological malignancies. The initial molecular dissection of BCR-ABL has linked the expression of this constitutively activated kinase with enhanced genomic instability. We directly evaluated the consequence of BCR-ABL expression on genomic instability using the Big Blue in vivo mutagenesis mouse system. We report that the expression of BCR-ABL in both spleens and kidneys confers a mutator phenotype represented by a statistically significant elevation in mutant frequencies.