Desjardins J, Mata J, Brown T, Graham D, Zon G, Iversen P. Cholesteryl-conjugated phosphorothioate oligodeoxynucleotides modulate CYP2B1 expression in vivo.
J Drug Target 1995;
2:477-85. [PMID:
7773609 DOI:
10.3109/10611869509015917]
[Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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.
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