Study shows group of enzymes is 10 times higher in CLL patients.
Researchers have discovered a unique pattern created by a specific family of enzymes in patients with chronic lymphocytic leukemia (CLL), a difficult-to-treat form of the disease and the one most common in adults.
Collectively known as cyclic nucleotide phosphodiesterases, the group of enzymes was 10 times higher in CLL patients than in normal individuals. The specific type of enzyme that investigators were targeting, phosphodiesterase 7B (PDE7B), controls in cells levels of cyclic AMP (cAMP). The cAMP molecule promotes programmed cell death, a process that is defective in CLL.
The scientists tested the effects of drugs that blocked PDE7B in CLL cells, and found that this raised cAMP levels and caused CLL cells to undergo cell death. Since PDE7B degrades cAMP, blocking PDE7B in essence takes the clamp off of programmed cell death, enabling CLL cells to die.
The research team said CLL cells could be killed even more by adding other drugs used to treat CLL. The investigators noted that a test for PDE7B might also potentially be used as a way to detect CLL, though they admit this has yet to be proven. Now they are exploring other potential treatment strategies to increase cAMP or disrupt its breakdown.
The scientists that collaborated on the study are located at the University of California, San Diego and the Moores UCSD Cancer Center health.ucsd.edu/cancer.asp. The team reports its findings this week in the Proceedings of the National Academy of Sciences.