Methods for diagnosing cancer and determining a susceptibility for developing cancer
View Patent ↗A human mutY polypeptide and DNA (RNA) encoding such polypeptide and a procedure for producing such polypeptide by recombinant techniques is disclosed. Also disclosed are methods for utilizing such polypeptide for preventing and/or treating diseases associated with a mutation in this gene. Diagnostic assays for identifying mutations in nucleic acid sequence endcoding a polypeptide of the present invention and for detecting altered levels of the polypeptide of the present invention for detecting diseases, for example, cancer, area also disclosed.
1. A method for determining whether a human subject harbors a mutation in an hMYH gene of the human subject that decreases an activity of the encoded hMYH protein, said method comprising:
providing an hMYH-encoding nucleotide sequence of the human subject; and
determining the presence or absence of a difference in a coding region in said hMYH-encoding nucleotide sequence, relative to SEQ ID NO:1, which results in decreased binding of the encoded hMYH protein to a substrate containing an A/GO mispair, or decreased glycosylase activity of the encoded hMYH protein on the mispaired adenosine in an A/GO mispair in a substrate containing an A/GO mispair.
2. The method of claim 1 , wherein said mutation is a substitution, a deletion, or an insertion.
3. The method of claim 1 , wherein said mutation results in a frame shift in, or a truncation of, the coding region.
4. The method of claim 1 , wherein said hMYH-encoding nucleotide sequence is a complementary DNA sequence.
5. The method of claim 4 , wherein the step of providing the hMYH-encoding nucleotide sequence comprises:
obtaining a sample from said patient;
isolating an hMYH-encoding nucleic acid from said sample; and
determining the nucleotide sequence of said hMYH-encoding nucleic acid.
6. The method of claim 5 , wherein said step of determining the nucleotide sequence of said hMYH-encoding nucleic acid is by DNA sequencing.
7. The method of claim 5 , further comprising amplifying a portion of said hMYH-encoding nucleic acid and determining the nucleotide sequence of the amplified nucleic acid.
8. The method of claim 5 wherein said sample is a blood sample, a urine sample, a saliva sample, a tissue biopsy sample, or an autopsy material sample.
9. The method of claim 8 wherein said sample is a blood sample.
10. A method for determining whether a human subject harbors a mutation in an hMYH gene of the human subject that decreases an activity of the encoded hMYH protein, said method comprising:
isolating an hMYH-encoding nucleic acid from a sample obtained from the human subject; and
determining the presence or absence of a mutation in a coding region in said hMYH-encoding nucleic acid, relative to SEQ ID NO:1, which results in decreased binding of the encoded hMYH protein to a substrate containing an A/GO mispair, or decreased glycosylase activity of the encoded hMYH protein on the mispaired adenosine in an A/GO mispair in a substrate containing an A/GO mispair.
11. The method of claim 10 wherein said mutation is a substitution, a deletion, or an insertion.
12. The method of claim 10 wherein said mutation results in a frame shift in, or a truncation of, the coding region.
13. The method of claim 10 wherein said hMYH-encoding nucleic acid is a complementary DNA.
14. The method of claim 10 wherein said hMYH-encoding nucleic acid is a genomic DNA.
15. The method of claim 10 wherein the step of determining the presence or absence of a mutation comprises amplifying said coding region in said hMYH-encoding nucleic acid.
16. The method of claim 15 wherein the step of determining the presence or absence of a mutation comprises detecting a change in the length of the amplified coding region.
17. The method of claim 15 wherein the step of determining the presence or absence of a mutation comprises nucleic acid hybridization.
18. The method of claim 10 further comprising
deducing the amino acid sequence encoded by the isolated hMYH-encoding nucleic acid; and
identifying a difference in the deduced amino acid sequence, relative to SEQ ID NO:2.
19. A method for determining whether a human subject harbors a mutation in an hMYH gene of the human subject that decreases an activity of the encoded hMYH protein, said method comprising:
Providing an amino acid sequence of an hMYH polypeptide of the human subject; and
determining the presence or absence of a difference in said amino acid sequence, relative to SEQ ID NO:2, which results in decreased binding of the encoded hMYH protein to a substrate containing an A/GO mispair or decreased glycosylase activity of the encoded hMYH protein on the mispaired adenosine in an A/GO mispair in a substrate containing an A/GO mispair.
20. The method of claim 19 , wherein said difference in said hMYH polypeptide sequence is a substitution, insertion, deletion or truncation.