Phosphorothioate oligonucleotide antisense

Henry SP, Novotny W, Leeds J, Auletta C, Kornbrust DJ. Inhibition of coagulation by a phosphorothioate oligonucleotide. Antisense Nucl Acid Drug Dev 1997 7 503-10. 

Mojcik CF, Gourley MF, Klinman DM et al (1993) Administration of a phosphorothioate oligonucleotide antisense to murine endogenous retroviral MCF env causes immune effects in vivo in a sequence-specific manner. Clin Immunol Immunopathol 67 130-136... 

A new antiviral agent, developed for treatment of CMV retinitis, can be administered by intravitreal injection. Formivirsen sodium is a phosphorothioate oligonucleotide that inhibits CMV replication through an antisense mechanism. It is formulated as a sterile and preservative-free solution and supplied in single-use vials (Vitravene ). The product is administered directly into the vitreous cavity posterior to the limbus through a 30-gauge needle. This procedure can be performed on an... 

Galbraith, W.M., Hobson, W.C., Giclas, PC., Schechter, P.J. and Agrawal, S. (1994). Complement activation and hemodynamic changes following intravenous administration of phosphorothioate oligonucleotides in the monkey. Antisense Res. Dev. 4 201-206. 

Peng, B., Andrews, J., Nestorov, I., Brennan, B., Nicklin, P. and Rowland, M. (2001) Tissue distribution and physiologically based pharmacokinetics of antisense phosphorothioate oligonucleotide ISIS 1082 in rat. Antisense Nucleic Acid Drug Develop., 11, 15-27. 

McIntyre, K.W., Lombard-Gillooly, K., Perez, J.R., Kunsch, C., Sarmiento, U.M., Larigan, J.D. et al. (1993) A sense phosphorothioate oligonucleotide directed to the initiation codon of transcription factor NF-kappa B p65 causes sequence-specific immune stimulation. Antisense Res. Dev., 3, 309-322. 

Pisetsky, D.S. and Reich, C.F. (1994) Stimulation of murine lymphocyte proliferation by a phosphorothioate oligonucleotide with antisense activity for herpes simplex virus. Life Sci., 54, 101-107. 

The term (XG + Xc) is the sum of the mole fractions of guanine and cytidine in the antisense strand. The mole fraction of any nucleobase is equal to the number of nucleotides containing that base divided by the total number of nucleotides in the oligonucleotide strand. [M+] is the molar concentration of monovalent cations. In a typical mammalian cell, [K + ] is 140 mM, and [Na+ ] is 10 mM. L is the length of the duplex in base pairs. Based on Equation 6.2 and the assumption that phosphorothioate oligonucleotides behave as regular DNA, fomivirsen (6.17) would have a predicted Tm of 59 °C. Equation 6.1 predicts 64 °C. More complex forms of Equation 6.2 with increased accuracy appear regularly in the literature.8... 

Yu, R.Z., R.S. Geary, J.M. Leeds,T. Ushiro-Watanabe, M. Moore, J. Fitchett, J. Matson, T. Burckin, M.V. Templin, and A.A. Levin. 2001. Comparison of pharmacokinetics and tissue disposition of an antisense phosphorothioate oligonucleotide target-... 

P.J. Schechter. 1999. Pharmacokinetics and tolerability of intravenous trecovirsen (GEM 91), an antisense phosphorothioate oligonucleotide, in HIV-positive subjects. /. Clin. Pharmacol. 39 47-54. 

R. Crooke, N.M. Dean, and A.A. Levin. 2001. Pharmacokinetics and pharmacodynamics of an antisense phosphorothioate oligonucleotide targeting Fas mRNA in mice./. Pharmacol. Exp. Ther. 296 388-395. 

Boado et al. [28] devised delivery systems based on conjugates of streptavidin and the 0X26 monoclonal antibody directed to the transferrin receptor as a carrier for the transport of ASO. These delivery systems were found to transport peptide nucleic acid antisense molecules, but not ASO, across the BBB. These authors attributed this difference to preferential binding of phosphorothioate oligonucleotide to plasma protein instead of the antibody complex, which reduced their transport. 

Bayever E, Iversen PL, Bishop MR, et al, Systemic administration of a phosphorothioate oligonucleotide with a sequence complementary to p53 for acute myelogenous leukemia and myelodysplastic syndrome initial results of a phase I trial. Antisense Res Dev 1993 4(4) 383-390,... 

Cornish KG, Iversen PL, Smith L, Arneson M, Bayever E. Cardiovascular effects of a phosphorothioate oligonucleotide with sequence antisense to p53 in the conscious rhesus monkey, Pharmacol Commun 1993 3 239-247. 

Zhao Q,Temsamani J, Zhou R-Z, Agrawal S. Pattern and kinetics of cytokine production following administration of phosphorothioate oligonucleotides in mice. Antisense NuclAcid Drug Dev 1997 7 495-502. 

As phosphorothioate oligonucleotides are widely used as antisense agents, there have been a number of reports on their mode of action. Using Rp and Sp phosphorothioate internucleotide linkages in ODNs, it was shown that Serratia marcescens endonuclease hydrolyses the Rp phosphorothioate bond with inversion of configuration at phosphorus. The presence of an Sp phosphorothioate... 

Binding and Effects of Binding to Non-nucleic Acid Targets. Phosphorothioate oligonucleotides tend to bind to many proteins and those interactions are influenced by many factors. The effects of binding can influence cell uptake, distribution, metabolism, and excretion. They may induce non-antisense effects that can be mistakenly interpreted as... 

In conclusion, phosphorothioate oligonucleotides may interact with a wide range of proteins through several types of mechanisms. These interactions may influence the pharmacokinetic, pharmacologic, and toxicologic properties of these molecules. They may also complicate studies on the mechanism of action of these drugs, and may obscure an antisense activity. For example, phosphorothio-... 

Human Safety. At Isis, we have had the opportunity to study approximately 10 phosphorothioate oligonucleotides in humans. We have studied antisense drugs administered intravitreally, intradermally, subcutaneously, intravenously, and topically. Vitravene, an intravitreally administered drug, is commercially available around the world. 

Phosphorothioate oligonucleotides have perhaps outperformed many expectations. They display attractive parenteral pharmacokinetic properties. They have produced potent systemic effects in a number of animal models and, in many experiments, the antisense mechanism has been directly demonstrated as the hoped-for selectivity. Further, these compounds appear to display satisfactory therapeutic indices for many indications. 

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