Aptamers and diagnostic methods for detecting the EGF receptor
The present invention provides aptamers that specifically bind to the EGF receptor in a sample, and diagnostic and analytical methods using those aptamers.
1. An aptamer comprising the nucleotide sequence:
XGANNGNNYGANNCNN (SEQ ID NO: 55);
wherein
X is a G, C or A;
Y is a G or A; and
N is, independently a 5-position modified 2′-deoxyuridine selected from the group consisting of 5-(N-benzylcarboxyamide)-2′-deoxyuracilyl, 5-(N-isobutylcarboxyamide)-2′-deoxyuridine, 5-(N-tryptaminocarboxyamide)-2′-deoxyuridine, 5-(N-[1-(3-trimethylamonium) propyl]carboxyamide)-2′-deoxyuridine chloride, 5-(N-naphthylmethylcarboxamide)-2′-deoxyuridine, and 5-(N-[1-(2,3-dihydroxypropyl)]carboxyamide)-2′-deoxyuridine.
2. The aptamer of claim 1 , wherein said 5-position modified 2′-deoxyuridine is a 5-(N-benzylcarboxyamide)-2′-deoxyuridine (BndU).
3. The aptamer of claim 1 , wherein the aptamer is capable of binding to Epidermal Growth Factor receptor (EGFR).
4. The aptamer of claim 3 , wherein the binding of the aptamer to EGFR is reduced in a dose-dependent manner based on the presence of an EGFR antagonist.
5. The aptamer of claim 4 , wherein the EGFR antagonist is selected from the group consisting of cetuximab and panitumumab.
6. The aptamer of claim 4 , wherein the K d of the aptamer to EGFR is at least 10-fold greater based on the presence of the EGFR antagonist relative to the K d of the aptamer to free EGFR.
7. The aptamer of claim 4 , wherein the K d of the aptamer to EGFR is at least 10 2 -fold greater based on the presence of the EGFR antagonist relative to the K d of the aptamer to free EGFR.
8. The aptamer of claim 1 , wherein the aptamer binds to the extracellular domain of EGFR.
9. An aptamer that binds to EGFR comprising a nucleotide sequence selected from the group consisting of SEQ. ID. NOS: 1-54.
10. An aptamer that binds EGFR comprising a nucleotide sequence having at least 90% identity to anyone of the nucleotide sequences of SEQ ID NOs: 1-54.