title: Preclinical activity of 8-chloroadenosine with mantle cell lymphoma: roles of energy depletion and inhibition of DNA and RNA synthesis.
abstract: 8-Chloroadenosine (8-Cl-Ado), an RNA-directed nucleoside analogue, is currently under evaluation in phase I clinical trials for treatment of chronic lymphocytic leukaemia. In the current study, the efficacy of 8-Cl-Ado was evaluated using mantle cell lymphoma (MCL) cell lines: Granta 519, JeKo, Mino, and SP-53. After continuous exposure to 10 mumol/l 8-Cl-Ado for 24 h, loss of mitochondrial transmembrane potential and poly [adenosine diphosphate (ADP)-ribose] polymerase (PARP) cleavage were detected in three of four cell lines. Reduced ATP levels (30-60% reduction) and concurrent 8-Cl-ATP accumulation were highly associated with cell death (P < 0.01). The intracellular 8-Cl-ATP concentrations were also highly correlated with inhibition of global transcription (50-90%, r(2) = 0.90, P < 0.01). However, the inhibition of transcription only accounted for 30-40% of cell death as determined by equivalent inhibition with actinomycin D. Likewise, short-lived mRNAs, those encoding cyclin D1 and Mcl-1, were not consistently reduced after treatment. Unique to MCL as compared to other haematological malignancies, 8-Cl-Ado inhibited the rates of DNA synthesis and selectively depleted dATP pools (50-80%). We conclude that the DNA and RNA directed actions of 8-Cl-Ado in combination with depleted energetics may promote cell death and inhibit growth of MCL cell lines.
authors.affiliation: Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Dennison
authors.forename: Kumudha
authors.initials: K
authors.lastname: Balakrishnan
authors.forename: Varsha
authors.initials: V
authors.lastname: Gandhi
mesh_terms: D015762:2-Chloroadenosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000970:Antineoplastic Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004273:DNA, Neoplasm / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000378:metabolism / Q000473:pathology*; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D015762:2-Chloroadenosine; D000255:Adenosine Triphosphate; C075440:8-chloroadenosine