Cholesteryl-conjugated phosphorothioate oligodeoxynucleotides modulate CYP2B1 expression in vivo

J Drug Target. 1995;2(6):477-85. doi: 10.3109/10611869509015917.

Abstract

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Aryl Hydrocarbon Hydroxylases*
  • Base Sequence
  • Biological Availability
  • Cholesterol / metabolism*
  • Cytochrome P-450 CYP2B1
  • Cytochrome P-450 CYP2E1
  • Cytochrome P-450 Enzyme System / drug effects
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism
  • Drug Delivery Systems
  • Gene Expression Regulation, Enzymologic / drug effects*
  • Gene Expression Regulation, Enzymologic / genetics
  • Hexobarbital / pharmacology
  • Injections, Intraperitoneal
  • Liver / cytology
  • Liver / drug effects
  • Liver / enzymology
  • Male
  • Microsomes, Liver / drug effects
  • Microsomes, Liver / enzymology
  • Mixed Function Oxygenases / metabolism
  • Molecular Sequence Data
  • Oligonucleotides, Antisense / administration & dosage
  • Oligonucleotides, Antisense / pharmacokinetics
  • Oligonucleotides, Antisense / pharmacology*
  • Oxidoreductases / drug effects
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism
  • RNA, Messenger / chemistry
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Sleep / drug effects
  • Software
  • Steroid Hydroxylases / drug effects
  • Steroid Hydroxylases / genetics*
  • Thionucleotides / pharmacology*

Substances

  • Oligonucleotides, Antisense
  • RNA, Messenger
  • Thionucleotides
  • Cytochrome P-450 Enzyme System
  • Cholesterol
  • Hexobarbital
  • Mixed Function Oxygenases
  • Oxidoreductases
  • Steroid Hydroxylases
  • Cytochrome P-450 CYP2E1
  • Aryl Hydrocarbon Hydroxylases
  • Cytochrome P-450 CYP2B1
  • steroid 16-beta-hydroxylase