Aptamers, multimeric aptamers and uses thereof

1. An isolated aptamer comprising a nucleic acid sequence selected from the group consisting of SEQ ID NO: 1, 2 and 3.

2. A multimeric aptamer comprising a plurality of monomers, wherein at least one monomer of said plurality of monomers is the aptamer of claim 1 .

3. The aptamer of claim 1 , being attached to a detectable moiety.

4. The aptamer of claim 1 , being attached to a therapeutic moiety.

5. A pharmaceutical composition comprising as an active ingredient the aptamer of claim 1 and a pharmaceutically acceptable carrier or diluent.

6. A method of detecting an expression of an ErbB receptor molecule on a cell, the method comprising:

(a) contacting the cell or a preparation thereof with the aptamer of claim 1 under conditions which allow complex formation between said ErbB receptor molecule and the aptamer;

(b) detecting a presence or level of said complex, thereby detecting expression of said ErbB receptor molecule.

7. A method of delivering a therapeutic moiety to an ErbB expressing cell in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of the aptamer of claim 4 , thereby delivering the therapeutic moiety to the subject in need thereof.

8. A method of killing or arresting growth of tumor cells overexpressing an ErbB receptor molecule in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of the aptamer of claim 1 , thereby killing or arresting growth of the tumor cells overexpressing an ErbB receptor molecule.

9. A method of treating cancer in a subject in need thereof the method comprising administering to the subject a therapeutically effective amount of the aptamer of claim 1 , thereby treating the cancer in the subject.

10. A multimeric aptamer as set forth in SEQ ID NO: 7.

11. The multimeric aptamer of claim 2 , wherein said multimeric aptamer is devoid of spacers between said plurality of monomers.