Sequence and chemistry requirements for a novel aptameric oligonucleotide inhibitor of EGF receptor tyrosine kinase activity

Akhtar, Saghir, Dunnion, Debbie, Poyner, David, Ackroyd, John, Bibby, Mike and Double, John (2002). Sequence and chemistry requirements for a novel aptameric oligonucleotide inhibitor of EGF receptor tyrosine kinase activity. Biochemical Pharmacology, 63 (12), pp. 2187-2195.

Abstract

We have previously identified a phosphorothioate oligonucleotide (PS-ODN) that inhibited epidermal growth factor receptor tyrosine kinase (TK) activity both in cell fractions and in intact A431 cells. Since ODN-based TK inhibitors may have anti-cancer applications and may also help understand the non-antisense mediated effects of PS-ODNs, we have further studied the sequence and chemistry requirements of the parent PS-ODN (sequence: 5′-GGA GGG TCG CAT CGC-3′) as a sequence-dependent TK inhibitor. Sequence deletion and substitution studies revealed that the 5′-terminal GGA GGG hexamer sequence in the parent compound was essential for anti-TK activity in A431 cells. Site-specific substitution of any G with a T in this 5′-terminal motif within the parent compound caused a significant loss in anti-TK activity. The fully PS-modified hexameric motif alone exhibited equipotent activity as the parent 15-mer whereas phosphodiester (PO) or 2′-O-methyl-modified versions of this motif had significantly reduced anti-TK activity. Further, T substitutions within the two 5′-terminal G residues of the hexameric PS-ODN to produce a sequence, TTA GGG, representing the telomeric repeats in human chromosomes, also did not exhibit a significant anti-TK activity. Multiple repeats of the active hexameric motif in PS-ODNs resulted in more potent inhibitors of TK activity than the parent ODN. These results suggested that PS-ODNs, but not PO or 2′-O-methyl modified ODNs, containing the GGA GGG motif can exert potent anti-TK activity which may be desirable in some anti-tumor applications. Additionally, the presence of this previously unidentified motif in antisense PS-ODN constructs may contribute to their biological effects in vitro and in vivo and should be accounted for in the design of the PS-modified antisense ODNs. © 2002 Published by Elsevier Science Inc.

Publication DOI: https://doi.org/10.1016/S0006-2952(02)00985-1
Divisions: Life & Health Sciences > Pharmacy
Life & Health Sciences
Uncontrolled Keywords: antisense oligodeoxynucleotide,aptamer,phosphorothioate,receptor tyrosine kinase inhibitor,Pharmacology
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
Published Date: 2002-06-15
Authors: Akhtar, Saghir
Dunnion, Debbie
Poyner, David ( 0000-0003-1590-112X)
Ackroyd, John
Bibby, Mike
Double, John

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