Cholesteryl-conjugated phosphorothioate oligodeoxynucleotides modulate CYP2B1 expression in vivo.
5' cholesteryl-conjugated phosphorothioate oligodeoxynucleotides with sequence complementary to the rat CYP2B1 mRNA were evaluated in adult male Sprague-Dawley rats for their pharmacokinetic properties, toxicity, and ability to modulate CYP2B1 expression in vivo. Following intraperitoneal administration of 35S-labelled oligodeoxynucleotides, volume of distribution for the phosphorothioate was 0.33 l/kg while the 5' cholesteryl-conjugate oligodeoxynucleotide was 0.12 l/kg. The elimination half-life was 23.2 and 55.4 hrs for cholesteryl-modified and unmodified oligodeoxynucleotides, respectively. Cholesteryl-conjugate oligodeoxynucleotide toxicity was detected at a dose of 1.0 mg/kg and consisted primarily of midzonal liver cell enlargement and increased total RNA. Hexobarbital sleep times, a measure of CYP2B1 enzyme activity in vivo, increased from 21.9 minutes in saline-treated animals to 29.5 minutes in cholesterol oligodeoxynucleotide-treated animals. A significant decrease in liver microsomal pentoxyresorufin O-dealkylase enzyme activity, a CYP2B1/2 specific assay, was observed but not a change in p-nitrophenol hydroxylase activity, a specific CYP2E1 assay. These data indicate that in vivo modulation of the CYP2B1 gene can be accomplished with synthetic phosphorothioate oligodeoxynucleotides in a sequence-specific manner. Further, cholesteryl conjugation to the 5' end of the oligodeoxynucleotide enhanced potency despite lesser bioavailability.
Desjardins
J
J
Department of Pharmacology, University of Nebraska Medical Center, Omaha 68198-6260, USA.
Mata
J
J
Brown
T
T
Graham
D
D
Zon
G
G
Iversen
P
P
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D001483:Base Sequence; D001682:Biological Availability; D002784:Cholesterol / Q000378:metabolism*; D019362:Cytochrome P-450 CYP2B1; D019392:Cytochrome P-450 CYP2E1; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D016503:Drug Delivery Systems; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects* / Q000235:genetics; D006591:Hexobarbital / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D010088:Oxidoreductases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000187:drug effects; D012984:Software; D013250:Steroid Hydroxylases / Q000187:drug effects / Q000235:genetics*; D013873:Thionucleotides / Q000494:pharmacology*
D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D013873:Thionucleotides; D003577:Cytochrome P-450 Enzyme System; D002784:Cholesterol; D006591:Hexobarbital; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D013250:Steroid Hydroxylases; D019392:Cytochrome P-450 CYP2E1; D001189:Aryl Hydrocarbon Hydroxylases; D019362:Cytochrome P-450 CYP2B1; C025619:steroid 16-beta-hydroxylase