Enhanced Expression and Activity of DNA Polymerase β in Chronic Myelogenous Leukemia

Abstract

Background: Chronic myelogenous leukemia (CML) is characterized by an initial chronic phase that invariably evolves to the more aggressive phase of blast crisis. Although the determinants of this transition are still unknown, it has been shown that the blast crisis is accompanied by genetic instability. Materials and Methods: The expression and activity of the error-prone DNA polymerase beta (pol β) were investigated in blood samples from CML patients, by Western blotting and by an in vitro replication assay, respectively. Results: Pol β expression and activity were significantly higher in CML samples compared to those of healthy donors. Conclusion: Our results suggest that the excess of pol β in CML could contribute to the genetic instability observed during the evolution of the disease from the chronic phase to blast crisis.