title: Antisense oligodeoxyribonucleotides suppress hematologic cell growth through stepwise release of deoxyribonucleotides.
abstract: Antisense oligodeoxyribonucleotides (ODNs) are now being extensively investigated in an attempt to achieve cell growth suppression through specific targeting of genes related to cell proliferation, despite increasing evidence of non-antisense cytotoxic effects. In the context of anti-BCR/ABL antisense strategies in chronic myeloid leukemia, we have reexamined the antiproliferative effect of phosphodiester and phosphorothioate ODNs on the leukemic cell line BV173 and on CD34+ bone marrow cells in liquid culture. The 3' sequences of the ODNs determine their effect. At concentrations of 10 micromol/L (for phosphorothioate ODNs) or 25 micromol/L (for phosphodiester ODNs), all the tested ODNs exert an antiproliferative activity, except those that contain a cytosine residue at either their two most terminal 3' positions. We show that this antiproliferative effect is due to the toxicity of the d-NMPs (5' monophosphate deoxyribonucleosides), the enzymatic hydrolysis products of the ODNs in culture medium. The toxicity of the d-NMPs on hematologic cells depends on their nature (d-CMP [2'deoxycytidine 5'-monophosphate] is not cytotoxic), on their concentration (d-GMP [2'-deoxyguanosine 5'-monophosphate], TMP [thymidine 5'-monophosphate], and d-AMP [2'-deoxyadenosine 5'-monophosphate] are cytotoxic at concentrations between 5 and 10 micromol/L), and on the coincident presence of other d-NMPs in the culture medium (d-CMP neutralizes the toxicity of d-AMP, d-GMP, or TMP). The antiproliferative activity of ODNs is thus restricted to conditions where the 3' hydrolysis process by exonucleases generates significant amounts of d-NMPs with a low proportion of d-CMP. Our results reveal a novel example of a nonantisense effect of ODNs, which should be taken into account when performing any experiment using assumed antisense ODNs.
authors.affiliation: Laboratoire de Biologie Moleculaire Hématologique, Cliniques St Luc, Université Catholique de Louvain, Clos Chapelle-aux-champs, Brussels, Belgium.
authors.forename: J L
authors.initials: JL
authors.lastname: Vaerman
authors.forename: P
authors.initials: P
authors.lastname: Moureau
authors.forename: F
authors.initials: F
authors.lastname: Deldime
authors.forename: P
authors.initials: P
authors.lastname: Lewalle
authors.forename: C
authors.initials: C
authors.lastname: Lammineur
authors.forename: F
authors.initials: F
authors.lastname: Morschhauser
authors.forename: P
authors.initials: P
authors.lastname: Martiat
mesh_terms: D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D007938:Leukemia / Q000235:genetics / Q000473:pathology*; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology*; D013873:Thionucleotides / Q000235:genetics / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D016376:Oligonucleotides, Antisense; D013873:Thionucleotides; D016044:Fusion Proteins, bcr-abl