Deoxyadenosine analogs induce programmed cell death in chronic lymphocytic leukemia cells by damaging the DNA and by directly affecting the mitochondria.

Author(s): Genini D, Adachi S, Chao Q, Rose DW, Carrera CJ, Cottam HB, Carson DA, Leoni LM

Affiliation(s): Department of Medicine and The Sam and Rose Stein Institute for Research on Aging, Whittier Diabetes Program, University of California, San Diego, La Jolla, CA, USA.

Publication date & source: 2000-11-15, Blood., 96(10):3537-43.

Publication type:

Adenine deoxynucleosides induce apoptosis in quiescent lymphocytes and are thus useful drugs for the treatment of indolent lymphoproliferative diseases. To explain why deoxyadenosine and its analogs are toxic to a cell that is not undergoing replicative DNA synthesis, several mechanisms have been proposed, including the direct binding of dATP to the pro-apoptotic factor Apaf-1 and the activation of the caspase-9 and -3 pathways. In this study it is shown, by means of several assays on whole cells and isolated mitochondria, that 2-chloro-2'-deoxyadenosine (2CdA) and 2-choloro-2'-ara-fluorodeoxyadenosine (CaFdA) disrupt the integrity of mitochondria from primary chronic lymphocytic leukemia (B-CLL) cells. The nucleoside-induced damage leads to the release of the pro-apoptotic mitochondrial proteins cytochrome c and apoptosis-inducing factor. The other adenine deoxynucleosides tested displayed comparable DNA-damaging potency but did not affect mitochondrial function. Interference with mitochondrial integrity, thus, may be a factor in the potent cytotoxic effects of 2CdA and CaFdA toward nondividing lymphocytes.