Stem-loop compositions and methods for inhibiting vascular endothelial growth factor
The application discloses methods and compositions for inhibiting functions associated with vascular endothelial growth factor-A (VEGF-A). The methods and compositions may involve the use of pan-variant specific aptamers for binding to VEGF-A, and preventing or reducing association of VEGF-A with Flt-1, KDR, or Nrp-1. The methods and compositions may include one or more aptamers that bind to receptor binding face of VEGF-A. The methods and compositions may include one or more aptamers that bind to a receptor binding domain of VEGF-A. The application further provides anti-VEGF-A aptamers for the treatment of ocular diseases or disorders. In some cases, the anti-VEGF-A aptamers may have a stem-loop secondary structure.
1 . An aptamer having a nucleic acid sequence, wherein said aptamer comprises a stem-loop secondary structure which specifically binds to and inhibits at least one of VEGF-A 121 and VEGF-A 110 , wherein said aptamer comprises, in a 5′ to 3′ direction: (i) a first side of a first base paired stem (S1); (ii) optionally, a first loop (L1); (iii) a first side of a second base paired stern (S2); (iv) a second loop (L2); (v) a second side of said second base paired stem (S2′); (vi) a third loop (L3); (vii) a first side of a third base paired stem (S3); (vii) a fourth loop (L4); (viii) a second side of said third base paired stem (S3′); (ix) a fifth loop (L5); and (x) a second side of said first base paired stem (S1′), wherein the aptamer comprises a consensus 5′-nucleic acid sequence comprising HNBYHDNNN*NNKNGCNNWGGGRUNDNDHNWYCCCGNNNNNYNKVNW-3′ (SEQ ID NO: 5), where H is A, C, or U; N is A, C, G, or U; Bis C, G, or U; Y is Cor U; N* is A, C, G, U, deleted entirely, or a non-nucleotidyl spacer 3 modification, a 6 carbon alkyl linker (1,6-hexanediol), or a spacer 9 (triethyleneglycol) modification; D is A, G, or U; K is G or U; W is A or U; R is A or G; and V is A, C, or G.
2 . The aptamer of claim 1 , wherein S1′ comprises between two and eight nucleotides and forms at least one base pair with S1.
3 . The aptamer of claim 1 , wherein S1 comprises a consensus nucleic acid sequence comprising 5′-HNBYHDNN-3′, and S1′ comprises a consensus nucleic acid sequence comprising 5′-NNYNKVNW-3′, where His A, C, or U; N is A, C, G, or U; B is C, G, or U; Y is C or U; Dis A, G, or U; K is G or U; and W is A or U.
4 . The aptamer of claim 1 , wherein L1 comprises a consensus nucleic acid sequence comprising 5′-N *-3′, wherein N* is A, C, G, U, a 3-carbon non-nucleotidyl spacer, two 3 carbon non-nucleotidyl spacers, a 6-carbon non-nucleotidyl spacer, or a 9-carbon non-nucleotidyl spacer.
5 . The aptamer of claim 1 , wherein S2 comprises a consensus nucleic acid sequence comprising 5′-NN-3′, and S2′ comprises a consensus nucleic acid sequence comprising 5′-NN-3′, where N is A, C, G, or U.
6 . The aptamer of claim 1 , wherein L2 comprises up to four nucleotides.
7 . The aptamer of claim 1 , wherein L2 comprises a consensus nucleic acid sequence comprising 5′-KNGC-3′, where K is G or U; and N is A, C, G or U.
8 . The aptamer of claim 1 , wherein S3′ comprises between four and eight nucleotides and forms at least one base pair with said S1.
9 . The aptamer of claim 1 , wherein S3 comprises a consensus nucleic acid sequence comprising 5′-GRGRWN-3′, and S3′ comprises a consensus nucleic acid sequence comprising 5′-NHYCYC-3′, where R is A or G; N is A, C, G, or U; W is A or U; and Y is C or U.
10 . The aptamer of claim 1 , wherein L3 comprises up to one nucleotide and comprises a consensus nucleic acid sequence comprising 5′-W-3′, where W is A or U.
11 . The aptamer of claim 1 , wherein L4 comprises three, four, six, or eight nucleotides.
12 . The aptamer of claim 1 , wherein L4 comprises a consensus nucleic acid sequence comprising 5′-KNNNNW-3′, where K is G or U; N is A, C, G, or U; and Wis A or U.
13 . The aptamer of claim 1 , wherein L5 comprises up to four nucleotides.
14 . The aptamer of claim 1 , wherein L5 comprises a consensus nucleic acid sequence comprising 5′-GNNN-3′, where N is A, C, G, or U.
15 . The aptamer of claim 1 , wherein the 3-carbon non-nucleotidyl spacer is 1,3-propanediol.
16 . The aptamer of claim 1 , wherein the aptamer is conjugated to a polyethylene glycol (PEG) molecule.
17 . A method of treating an ocular disease or disorder in a subject in need thereof, comprising administering to the subject an aptamer of claim 1 , thereby treating said ocular disease or disorder.
18 . The method of claim 17 , wherein the ocular disease or disorder is selected from the group consisting of diabetic retinopathy, retinopathy of prematurity, central retinal vein occlusion, macular edema, choroidal neovascularization, neovascular age-related macular degeneration, myopic choroidal neovascularization, punctate inner choroidopathy, ocular histoplasmosis syndrome, familial exudative vitreoretinopathy, retinoblastoma, or combinations thereof.
19 . The method of claim 17 , wherein the subject is a human.