Preparation of Conjugates of Oligodeoxynucleotides and Lipid Structures and Their Interaction with Low-Density Lipoprotein

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• 作者：Erik T. Rump ; Remco L. A. de Vrueh ; Leo A. J. M. Sliedregt ; Erik A. L. Biessen ; Theo J. C. van Berkel ; and Martin K. Bijsterbosch
• 刊名：Bioconjugate Chemistry
• 出版年：1998
• 出版时间：May 1998
• 年：1998
• 卷：9
• 期：3
• 页码：341 - 349
• 全文大小：154K
• 年卷期：v.9,no.3(May 1998)
• ISSN：1520-4812

文摘

The high expression level of receptors for low-density lipoprotein (LDL)on tumor cells makes LDL anattractive carrier for selective delivery of drugs to these cells.The aim of this study is to allowincorporation of oncogene-directed antisense oligodeoxynucleotides(ODNs) into the lipid moiety ofLDL. Therefore, ODNs were conjugated with oleic acid, cholesterol,and several other steroid lipids.These latter steroid lipids were synthesized starting from bileacids and were varied in lipophilicityby attaching oleic acid ester structures. The lipid structures,activated as pentafluorophenyl esters,were conjugated in solution phase to 3'-amino-tailed ODNs. TheODNs conjugated with lithocholicacid, oleic acid, and cholesterol could easily be purified by reversedphase (RP)-HPLC. However, theODNs conjugated with the oleoyl steroid ester structures irreversiblybound to the column material.These highly lipidic ODNs were separated from the nonconjugatedODN by electrophoresis in a 1%low-melting agarose gel containing 0.1% Tween 20. This method wasfound to be very effective inisolating the ODNs conjugated to the oleoyl steroid ester structures.The ODNs conjugated withcholesterol and the oleoyl esters of lithocholic and cholenic acidassociated readily and nearly completelywith LDL. However, the less lipidic ODNs and the ODN conjugatedwith the dioleoyl ester ofchenodeoxycholic acid did not and did incompletely associate,respectively. Lithocholic acid and oleicacid are probably not sufficiently lipophilic to induce associationwith LDL, whereas the dioleoyl esterstructure is probably too bulky and extended to allow partitioning intothe lipid moiety of LDL. Weconclude that several of the lipid-ODNs can associate readily withLDL, enabling delivery of oncogene-directed antisense ODNs via the LDL receptor pathway.