title: Inhibition of calmodulin-dependent phosphodiesterase induces apoptosis in human leukemic cells.
abstract: Cytosolic extracts from a human lymphoblastoid B-cell line, RPMI-8392, established from a patient with acute lymphocytic leukemia, contain two major forms of cyclic nucleotide phosphodiesterase (PDE): Ca2+-calmodulin dependent PDE (PDE1) and cAMP-specific PDE (PDE4). In contrast, normal quiescent human peripheral blood lymphocytes (HPBL) are devoid of PDE1 activity [Epstein, P. M., Moraski, S., Jr., and Hachisu, R. (1987) Biochem. J. 243, 533-539]. Using reverse transcription-polymerase chain reaction (RT-PCR), we show that the mRNA encoding the 63-kDa form of PDE1 (PDE1B1) is expressed in RPMI-8392 cells, but not in normal, resting HPBL. This mRNA is, however, induced in HPBL following mitogenic stimulation by phytohemagglutinin (PHA). Also using RT-PCR, the full open reading frame for human PDE1B1 cDNA was cloned from RPMI-8392 cells and it encodes a protein of 536 amino acids with 96% identity to bovine, rat, and mouse species. RT-PCR also identifies the presence of PDE1B1 in other human lymphoblastoid and leukemic cell lines of B- (RPMI-1788, Daudi) and T-(MOLT-4, NA, Jurkat) cell origin. Inhibition of PDE1 or PDE4 activity by selective inhibitors induced RPMI-8392 cells, as well as the other cell lines, to undergo apoptosis. Culture of RPMI-8392 cells with an 18-bp phosphorothioate antisense oligodeoxynucleotide, targeted against the translation initiation region of the RPMI-8392 mRNA, led to a specific reduction in the amount of PDE1B1 mRNA after 1 day, and its disappearance after 2 days, and induced apoptosis in these cells in a sequence specific manner. This suggests that PDEs, particularly PDE1B1, because its expression is selective, may be useful targets for inducing the death of leukemic cells.
authors.affiliation: Department of Pharmacology, University of Connecticut Health Center, Farmington 06030, USA.
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Paskind
authors.forename: P M
authors.initials: PM
authors.lastname: Epstein
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000502:physiology*; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone / Q000494:pharmacology; D000595:Amino Acid Sequence; D017209:Apoptosis; D001402:B-Lymphocytes / Q000201:enzymology*; D001483:Base Sequence; D003001:Cloning, Molecular; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008934:Mitogens / Q000494:pharmacology; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000502:physiology; D011760:Pyrrolidinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D020889:Rolipram; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000201:enzymology*; D014407:Tumor Cells, Cultured; D014748:Vinca Alkaloids / Q000494:pharmacology
chemical_list: D008934:Mitogens; D016376:Oligonucleotides, Antisense; D010726:Phosphodiesterase Inhibitors; D011760:Pyrrolidinones; D012333:RNA, Messenger; D014748:Vinca Alkaloids; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; C013983:vinpocetine; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517266:PDE1B protein, human; C517269:Pde1b protein, rat; D020889:Rolipram