Claims
- 1. A method for identifying a compound that modulates the biological activity of a native quadruplex DNA, which comprises
contacting a test quadruplex DNA in a chair conformation with a candidate compound; and determining the presence or absence of an interaction between the candidate compound and the test quadruplex DNA, whereby the candidate compound that interacts with the test quadruplex DNA is identified as the compound that modulates the biological activity of the native quadruplex DNA.
- 2. The method of claim 1, wherein the test quadruplex DNA comprises a nucleotide sequence selected from the group consisting of (GaXb)cGa, wherein
G is guanine; X is guanine, cytosine, adenine, or thymine; a is an integer between 2 to 6; b is an integer between 1 to 4; and c is the integer 3.
- 3. The method of claim 1, wherein the native quadruplex DNA comprises a nucleotide sequence selected from the group consisting of
- 4. The method of claim 1, wherein the native quadruplex DNA comprises a nucleotide sequence that is identical to a nucleotide sequence in the test quadruplex DNA.
- 5. The method of claim 1, wherein the chair conformation of the test quadruplex DNA is formed by incubating the DNA in a solution comprising potassium ions for a time period less than the time period required to form the basket conformation of the quadruplex DNA.
- 6. The method of claim 1, wherein the test quadruplex DNA comprises a mutation that prevents formation of the basket conformation.
- 7. The method of claim 1, wherein the test quadruplex DNA is coupled to a reporter expression system.
- 8. The method of claim 7, wherein the reporter expression system comprises a luciferase reporter.
- 9. The method of claim 1, wherein the interaction is assayed by a Taq polymerase arrest assay.
- 10. A method for identifying a compound that binds a native quadruplex DNA, which comprises
contacting a test quadruplex DNA in a chair conformation with a candidate compound; and determining the presence or absence of binding between the candidate compound and the test quadruplex DNA, whereby the candidate compound that binds the test quadruplex DNA is identified as the compound that binds the native quadruplex DNA.
- 11. The method of claim 10, wherein the test quadruplex DNA comprises a nucleotide sequence selected from the group consisting of (GaXb)cGa, wherein
G is guanine; X is guanine, cytosine, adenine, or thymine; a is an integer between 2 to 6; b is an integer between 1 to 4; and c is the integer 3.
- 12. The method of claim 10, wherein the native quadruplex DNA comprises a nucleotide sequence selected from the group consisting of
- 13. The method of claim 10, wherein the native quadruplex DNA comprises a nucleotide sequence that is identical to a nucleotide sequence in the test quadruplex DNA.
- 14. The method of claim 10, wherein the chair conformation of the quadruplex DNA is forned by incubating the DNA in a solution comprising potassium ions for a time period less than the time period required to form the basket conformation of the quadruplex DNA.
- 15. The method of claim 10, wherein the quadruplex DNA comprises a mutation that prevents formation of the basket conformation.
- 16. A method for modulating the biological activity of a biologically significant native quadruplex DNA, which comprises contacting a system comprising the native quadruplex DNA with a compound which interacts with a quadruplex DNA in a chair conformation; whereby the compound modulates the biological activity of the native quadruplex DNA.
- 17. The method of claim 16, wherein the native quadruplex DNA comprises a nucleotide sequence selected from the group consisting of (GaXb)cGa, wherein
G is guanine; X is guanine, cytosine, adenine, or thymine; a is an integer between 2 to 6; b is an integer between 1 to 4; and c is the integer 3.
- 18. The method of claim 16, wherein the native quadruplex DNA comprises a nucleotide sequence selected from the group consisting of
- 19. The method of claim 16, wherein the system is a cell.
- 20. The method of claim 16, wherein the system is an organism.
- 21. An isolated nucleic acid which comprises a nucleotide sequence selected from the group consisting of
- 22. The isolated nucleic acid of claim 21, wherein the nucleotide sequence is selected from the group consisting of TGGGGAGGGTGXGGAGGGTGGGG, TGGGGAGGGTGGGGAGXGTGGGG, or TGGGGAGGGTGXGGAGXGTGGGG, wherein G is guanine, A is adenine, C is cytosine, T is thymine, and X is a nucleotide other than guanine.
- 23. A method for determining whether a subject is at risk of developing cancer or at risk of having cancer, which comprises detecting the presence or absence of a polymorphic variant in a nucleic acid sample from the subject, wherein the polymorphic variation destabilizes a native quadruplex structure; whereby the presence of the polymorphic variant determines that the subject is at risk of developing the cancer or having the cancer.
- 24. The method of claim 23, wherein the cancer is colorectal cancer.
- 25. The method of claim 24, wherein the polymorphic variant is TGGGGAGGGTGXGGAGGGTGGGG, TGGGGAGGGTGGGGAGXGTGGGG, or TGGGGAGGGTGXGGAGXGTGGGG, wherein G is guanine, A is adenine, C is cytosine, T is thymine, and X is a nucleotide other than guanine.
- 26. The method of claim 25, wherein X is adenine.
- 27. The method of claim 23, wherein the nucleic acid sample is isolated from a colorectal tissue sample.
- 28. A method for detecting the presence or absence of cancer in a subject, which comprises detecting the presence or absence of a polymorphic variant in a nucleic acid sample from the subject, wherein the polymorphic variation destabilizes a native quadruplex structure; and if the presence of the polymorphic variant is detected in the nucleic acid sample, performing a further examination of the subject to detect the presence or absence of cancer.
- 29. The method of claim 28, wherein the cancer is colorectal cancer and the further examination is a colorectal examination.
- 30. The method of claim 29, which further comprises removing one or more polyps if polyps are identified in the colorectal examination.
- 31. A method for treating cancer in a subject, which comprises detecting the presence or absence of a polymorphic variant in a nucleic acid sample from the subject, wherein the polymorphic variation destabilizes a native quadruplex structure; and if the presence of the polymorphic variant is detected in the nucleic acid sample, treating the subject with a cancer treatment.
- 32. The method of claim 31, wherein the cancer is colorectal cancer and the cancer treatment is selected from the group consisting of surgical removal of the colorectal cancer, chemotherapy, radiation therapy, or a combination thereof.
- 33. The method of claim 31, wherein the cancer is colorectal cancer and the anticancer treatment is administration of a nucleic acid that specifically hybridizes to the polymorphic variant.
- 34. The method of claim 33, wherein the nucleic acid administered is a peptide nucleic acid.
- 35. The method of claim 34, wherein polymorphic variant comprises the nucleotide sequence TGGGGAGGGTGXGGAGGGTGGGG, TGGGGAGGGTGGGGAGXGTGGGG, or TGGGGAGGGTGXGGAGXGTGGGG, and the peptide nucleic acid comprises all or a portion of the nucleotide sequence CCCCACCCTCCYCACCCTCCCCA, CCCCACYCTCCCCACCCTCCCCA, or CCCCACYCTCCYCACCCTCCCCA, wherein G is guanine, A is adenine, C is cytosine, T is thymine, X is a nucleotide other than guanine, and Y is a nucleotide complementary to X.
- 36. The method of claim 33, wherein the nucleic acid is administered by colorectal delivery.
RELATED PATENT APPLICATIONS
[0001] This patent application claims the benefit of provisional patent application 60/404,966 filed Aug. 20, 2002 and provisional patent application 60/370,358 filed Apr. 5, 2002, having attorney docket number 532233000400 and 532233000401, respectively. Each of these provisional patent applications is entitled “Methods of regulating transcription by targeting quadruplex DNA” and names Adam Siddiqui-Jain et al. as inventors. This patent application also claims the benefit of a provisional application filed on Mar. 20, 2003, having attorney docket number 532233000402, entitled “Methods for targeting quadruplex DNA,” and names Adam Siddiqui-Jain et al. as inventors (application number not available at the time this application is filed). Each of these three provisional patent applications is hereby incorporated herein by reference in its entirety, including all drawings and cited documents.
STATEMENT OF GOVERNMENT SUPPORT
[0002] This invention was made in part with government support under Grant Nos. CA67760 and CA88310 awarded by the National Institutes of Health. The government has certain rights in this invention.
Provisional Applications (3)
|
Number |
Date |
Country |
|
60456637 |
Mar 2003 |
US |
|
60404966 |
Aug 2002 |
US |
|
60370358 |
Apr 2002 |
US |