Novel compositions and methods in cancer associated with altered expression of MCM3AP

1 . A method of diagnosing breast cancer comprising:

(a) measuring a level of a MCM3AP mRNA in a first sample, said first sample comprising a first tissue type of a first individual; and

(b) comparing the level of MCM3AP mRNA in (a) to:

(1) a level of the MCM3AP mRNA in a second sample, said second sample comprising a normal tissue type of said first individual, or

(2) a level of the MCM3AP mRNA in a third sample, said third sample comprising a normal tissue type from an unaffected individual;

wherein an increase of at least 50% between the level of the MCM3AP mRNA in (a) and the level of the MCM3AP mRNA in the second sample or the third sample indicates that the first individual has or is predisposed to breast cancer.

2 . The method of claim 1 wherein the MCM3AP mRNA has a nucleotide sequence of SEQ ID NO:5.

3 . A method of diagnosing breast cancer comprising:

(a) measuring a level of MCM3AP gene expression in a first sample, said first sample comprising a first tissue type of a first individual; and

(b) comparing the level of MCM3AP gene expression in (a) to:

(1) a level of MCM3AP gene expression in a second sample, said second sample comprising a normal tissue type of said first individual, or

(2) a level of MCM3AP gene expression in a third sample, said third sample comprising a normal tissue type from an unaffected individual;

wherein an increase of at least about 50% between the level of MCM3AP gene expression in (a) and the level of MCM3AP gene expression in the second sample or the third sample indicates that the first individual has or is predisposed to breast cancer.

4 . The method of claim 3 wherein the MCM3AP gene has a nucleotide sequence of SEQ ID NO:4.

5 . The method of claim 1 or claim 3 wherein the breast cancer is ductal adenocarcinoma.

6 . The method of claim 1 or claim 3 wherein the increase between the level of MCM3AP gene expression in (a) and the level of the MCM3AP gene expression in the second sample or the third sample is at least 100%.

7 . The method of claim 1 or claim 3 wherein the increase between the level of MCM3AP gene expression in (a) and the level of the MCM3AP gene expression in the second sample or the third sample is at least 150%.

8 . The method of claim 3 wherein the level of MCM3AP gene expression is determined by measuring MCM3AP mRNA (SEQ ID NO:5).

9 . A method of screening for anti-breast cancer activity comprising:

(a) contacting a cell that expresses MCM3AP with a candidate anti-breast cancer agent; and

(b) detecting a difference of at least about 50% between the level of MCM3AP gene expression in the cell in the presence and in the absence of the candidate anti-breast cancer agent,

wherein a difference between the level of MCM3AP gene expression in the cell in the presence and in the absence of the candidate anti-breast cancer agent of at least 50% indicates that the candidate anti-breast cancer agent has anti-breast cancer activity.

10 . The method of claim 9 wherein a difference of at least 100% between the level of MCM3AP gene expression in the cell in the presence and in the absence of the candidate anti-breast cancer agent indicates that the candidate anti-breast cancer agent has anti-breast cancer activity.

11 . The method of claim 9 wherein the candidate anti-breast cancer agent is an antibody, small organic compound, small inorganic compound, or polynucleotide.

12 . The method of claim 9 wherein the candidate anti-breast cancer agent is a monoclonal antibody.

13 . The method of claim 9 wherein the candidate anti-breast cancer agent is a human or humanized antibody.

14 . The method of claim 11 wherein the polynucleotide is an antisense oligonucleotide.

15 . The method of claim 9 wherein the breast cancer is ductal adenocarcinoma.