Beta-catenin targeting peptides and uses thereof

1. A β-catenin binding polypeptide comprising an α-helical segment, wherein the polypeptide comprises the amino acid sequence:

X 1 X 2 X 3 XL 4 X 5 Y 1 X 6 X 7 X 8 Y 2 X 9 X 10 X 11 A 12 X 13 X 14 X 15 ,

wherein

X 1 is selected from the group consisting of R, K and no amino acid;

X 2 is selected from the group consisting of R, K, W and no amino acid;

X 3 is selected from the group consisting of W, Y and Q;

X 4 is selected from the group consisting of P, S, W, A, F and L;

X 5 is selected from the group consisting of E, Q, R and W;

X 6 is selected from the group consisting of I and L;

X 7 is selected from the group consisting of I and L;

X 8 is selected from the group consisting of D and N;

X 9 is selected from the group consisting of H and W;

X 10 is selected from the group consisting of V, W, L, M, F, and I;

X 11 is selected from the group consisting of Q, E, L, D, H, R, S, and V;

X 12 is selected from the group consisting of R, S, and K;

X 13 is selected from the group consisting of V, I, L, W, F and H;

X 14 is selected from the group consisting of M, Norleucine, I, L, W, F and H;

X 15 is selected from the group consisting of R, G, P, E, H, K, Q, and no amino acid; and

Y 1 is selected from the group S, S 5 , R 5 , and Y 2 is selected from the group E, S 5 , and R 5 .

2. The polypeptide of claim 1 , wherein the amino acid of X 1 , X 2 , X 11 , X 12 , or X 15 is a positively charged amino acid and/or the amino acid of X 3 , X 4 , X 5 , X 6 , X 7 , X 9 , X 10 , X 13 or X 14 is a bulky, hydrophobic amino acid.

3. The polypeptide of claim 1 , wherein Y 1 and Y 2 are S 5 .

4. The polypeptide of claim 1 comprising a free N-terminus, an acetylated N-terminus, a linker molecule, a labeling moiety, an affinity tag, and/or a targeting moiety.

5. The polypeptide of claim 4 , wherein the linker molecule is β-Ala or PEG 1 .

6. The polypeptide of claim 4 , wherein the labeling moiety is FITC.

7. The polypeptide of claim 4 , wherein the affinity tag is biotin, FLAG, 6×His, or myc.

8. The polypeptide of claim 4 , wherein the targeting moiety is integrin, antibody, or antibody fragment.

9. A pharmaceutical composition comprising the polypeptide of claim 1 .

10. A method of treating a cancer that exhibits Wnt-signaling dependent growth in a subject, the method comprising administering to a subject the pharmaceutical composition of claim 9 in an amount sufficient to treat the cancer.

11. A method of modulating Wnt-mediated transcription, the method comprising contacting a cell with the polypeptide of claim 1 .

12. A method to inhibit cell proliferation that is dependent on aberrant Wnt-signaling, the method comprising contacting the cell with a polypeptide of claim 1 .

13. A β-catenin binding polypeptide comprising an α-helical segment, wherein the polypeptide comprises the amino acid sequence:

X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 X 13 X 14 X 15 X 16 ,

wherein

X 1 is selected from the group consisting of R, V, E, Q, T, K, W, and L;

X 2 is selected from the group consisting of W, S, L, N, Y, K, V, and Q:

X 3 is selected from the group consisting of P, L, S, W, A, and F;

X 4 is selected from the group consisting of E, Q, and W;

X 5 isS;

X 6 is I;

X 7 is L;

X 8 is D;

X 9 is selected from the group consisting of E and Q;

X 10 is H;

X 11 is selected from the group consisting of W, V, F, M, L, and I;

X 12 is selected from the group consisting of E, Q, H, D, V, and L;

X 13 is selected from the group consisting of R and K;

X 14 is selected from the group consisting of V and W;

X 15 is selected from the group consisting of M, W, F, and E; and

X 16 is selected from the group consisting of R, G, P, E, and Q, with the proviso that the sequence is not the wild-type sequence from Axin.

14. The polypeptide of claim 13 , wherein

X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 X 13 X 14 X 15 X 16 is modified to induce and/or stabilize an α-helical conformation.

15. The polypeptide of claim 14 , wherein the amino acids positioned at i, i+4 and/or i, i+7 are cross-linked by a hydrocarbon cross-link.

16. The polypeptide of claim 14 , wherein the modification is selected from the group consisting of a peptide staple, a lactam cross-link, a disulfide cross-link, α-methylation, N-caps, and a hydrogen bond surrogate.

17. The polypeptide of claim 16 , wherein the modification is a peptide staple.

18. The polypeptide of claim 17 , wherein the amino acids positioned at i, i+4 and/or i, i+7 are stapled.

19. The polypeptide of claim 13 , wherein the sequence is not ENPESILDEHVQRVMR (SEQ ID NO: 1) (amino acids 469-484 of rat axin).

20. A β-catenin binding polypeptide comprising an amino acid sequence of any one of SEQ ID NOs.: 28-58.

21. An isolated polypeptide comprising an α-helical segment, wherein the peptide binds β-catenin and comprises an amino acid sequence selected form the group consisting of the sequences: ENPES 5 ILDS 5 HVQRVM (SEQ ID NO:14), PES 5 ILDS 5 HVQRVM (SEQ ID NO:15), PES 5 ILDS 5 HVRRVMR (SEQ ID NO:16), PQS 5 ILDS 5 HVRRVMR (SEQ ID NO:17), PQS 5 ILDS 5 HVRRWMR (SEQ ID NO:18), PQS 5 ILDS 5 HVRRVWR (SEQ ID NO:19), RWPQS 5 ILDS 5 HVRRVWR (SEQ ID NO:20), RRWPQS 5 ILDS 5 HVRRVWR (SEQ ID NO:21), RWPRS 5 ILDS 5 HVRRVWR (SEQ ID NO:22), RRWPRS 5 ILDS 5 HVRRVWR (SEQ ID NO:23), RWPQS 5 ILDS 5 HVRRWNleR (SEQ ID NO:24), RWPRS 5 ILDS 5 HVRRWNleR (SEQ ID NO:25), RWPQS 5 ILDS 5 HVRRRWR (SEQ ID NO:26), RWPRS 5 ILDS 5 HVRRRWR (SEQ ID NO:27).