Methods and compositions for the inhibition of Stat5 in prostate cancer cells

1. A method of inhibiting prostate cancer cell growth, comprising inhibiting Stat5 activity in prostate cancer cells, wherein Stat5 activity is inhibited by contacting the prostate cancer cells with a small molecule that inhibits Stat5 activity or with an antibody that binds to a Stat5 polypeptide and inhibits Stat5 activity.

2. The method of claim 1 , wherein the small molecule is an inhibitor of a Stat5 tyrosine kinase that activates Stat5 in prostate cancer cells, or the antibody inhibits activation of Stat5 by a Stat5 tyrosine kinase in prostate cancer cells.

3. The method of claim 2 , wherein the Stat5 tyrosine kinase is Jak1, Jak2, Jak3, Tyk2, Src, Fyn, Yes, Lck, Hck, Blk, Fgr or Lyn.

4. The method of claim 1 , wherein the inhibition of Stat5 activity in the prostate cancer cells results in prostate cancer cell death.

5. The method of claim 1 , wherein the prostate cancer is primary prostate cancer, advanced prostate cancer or metastatic prostate cancer.

6. A method of treating prostate cancer in a male in need of such treatment, comprising administering to the male a therapeutically effective amount of a small molecule that inhibits Stat5 activity in prostate cancer cells of the male or a therapeutically effective amount of an antibody that binds to a Stat5 polypeptide and inhibits Stat5 activity in prostate cancer cells of the male.

7. The method of claim 6 , wherein the small molecule is an inhibitor of a Stat5 tyrosine kinase that activates Stat5 in prostate cancer cells, or the antibody inhibits activation of Stat5 by a Stat5 tyrosine kinase in prostate cancer cells.

8. The method of claim 7 , wherein the Stat5 tyrosine kinase is Jak1, Jak2, Jak3, Tyk2, Src, Fyn, Yes, Lck, Hck, Blk, Fgr or Lyn.

9. The method of claim 6 , wherein the inhibition of Stat5 activity in the prostate cancer cells results in prostate cancer cell death.

10. The method of claim 6 , wherein the prostate cancer is primary prostate cancer, advanced prostate cancer or metastatic prostate cancer.

11. A method of diagnosing or aiding in the diagnosis of prostate cancer in a male, comprising:

(a) obtaining a prostate tissue sample from a male; and

(b) determining whether activated Stat5 is present in cells of the prostate tissue sample, wherein the presence of activated Stat5 is an indication of prostate cancer in the male.

12. The method of claim 11 , wherein the prostate cancer is primary prostate cancer, advanced prostate cancer or metastatic prostate cancer.

13. The method of claim 11 , wherein the presence of activated Stat5 in (b) is detected by a method selected from the group consisting of: immunohistochemistry, immunocytochemistry and DNA-binding assays.

14. The method of claim 11 , wherein the activated Stat5 in (b) is nuclear Stat5.