Apolipoprotein A-II isoform as a biomarker for prostate cancer

• US 7,811,772 B2
• Filed: 01/06/2006
• Issued: 10/12/2010
• Est. Priority Date: 01/06/2005
• Status: Expired due to Fees

• Current Assignee: Eastern Virginia Medical School
• Original Assignee: Eastern Virginia Medical School
• Inventors: Ward, Michael D., Malik, Gunjan, Semmes, O. John
• Primary Examiner(s): Reddig; Peter J
• Application Number:
  US11/794,838
• Publication Number:
  US 20080248500A1
• Time in Patent Office: 1,740 Days
• Field of Search: None
• US Class Current: 435/7.1
• CPC Class Codes: G01N 2333/775 Apolipopeptides
• CPC Class Codes: G01N 33/57434 of prostate
• CPC Class Codes: G01N 33/92 involving lipids, e.g. cholesterol , lipoproteins, or their receptors steroid hormones G01N33/743

Abstract

The present invention provides a protein-based biomarker, ApoA-II isoform, that is useful in determining prostate cancer status in a patient. In particular, the biomarker of this invention is useful to classify a biological sample as prostate cancer or non-prostate cancer. The ability of ApoA-II to detect disease in patients with a normal prostate-specific antigen (PSA) makes the biomarker of this invention useful in identifying indolent disease. The biomarker can be detected by SELDI mass spectrometry, HPLC, PAGE and Western blotting.

Claims

1. A method for screening for prostate cancer or benign prostate hyperplasia in a subject comprising the steps of:

(a) providing a biological sample of a human physiological fluid or prostate tissue from the subject;

(b) contacting the biological sample with an antibody capable of capturing an ApoA-II isoform comprising;

(i) amino acid sequence VKSPELQAEAK (SEQ ID NO;

1); and

(ii) amino acid sequence SKEQLTPLIK (SEQ ID NO;

2);

(c) determining the amount of the bound ApoA-II isoform having a molecular weight of about 8943 Dalton +/−

15; and

(d) correlating the amount of the bound ApoA-II isoform having a molecular weight of about 8943 Dalton +/−

15 to a status of prostate cancer or benign prostate hyperplasia.

2. The method of claim 1, wherein the screening differentiates between prostate cancer versus normal.

3. The method of claim 1, wherein the screening differentiates between prostate cancer versus benign prostate hyperplasia.

4. The method of claim 1, wherein the screening is part of a diagnosis or prognosis of prostate cancer in the subject.

5. The method according to claim 1, wherein the human physiological fluid is whole blood or serum.

6. The method according to claim 1, wherein the human prostate tissue sample is a prostate cancer tissue sample or a benign prostate hyperplasia tissue sample.

7. The method according to claim 1, wherein the antibody is attached to a solid support.

8. The method according to claim 7, wherein the solid support is a mass spectrometry probe and the antibody is attached to the probe and wherein step (c) comprises detecting the bound ApoA-II isoform by mass spectrometry.

9. The method according to claim 1, wherein the antibody is selected from the group consisting of polyclonal antibodies, monoclonal antibodies, bispecific antibodies, human antibodies, humanized antibodies, chimeric antibodies, single chain antibodies, and Fv, FAb, and Fab₂ fragments thereof.

10. The method according to claim 1, further comprising the step of:

(e) comparing the amount of the ApoA-II isoform having a molecular weight of about 8943 Dalton +/−

15 in the biological sample with the amount of an ApoA-II isoform having a molecular weight of about 8943 Dalton +/−

15 in a biological sample from one or more subjects free from prostate cancer or with a previously determined reference range for an ApoA-II isoform having a molecular weight of about 8943 Dalton +/−

15 in subjects free from prostate cancer.

11. The method according to claim 1, wherein step (c) comprises high-performance liquid chromatography.

12. The method according to claim 1, wherein step (c) comprises polyacrylamide gel electrophoresis (PAGE) and Western blotting.

13. The method according to claim 12, wherein PAGE is 2-dimensional PAGE.

14. A method for screening for prostate cancer or benign prostate hyperplasia in a subject comprising the steps of:

(a) providing a biological sample of a human physiological fluid or prostate tissue from the subject;

(b) detecting or determining absence, presence or amount of an ApoA-II isoform, the ApoA-II isoform comprising;

(i) amino acid sequence VKSPELQAEAK (SEQ ID NO;

1); and

(ii) amino acid sequence SKEQLTPLIK (SEQ ID NO;

2);

and wherein the ApoA-II isoform has a molecular weight of about 8943 Dalton +/−

15; and

(c) correlating the absence, presence or amount of the ApoA-II isoform to a status of prostate cancer or benign prostate hyperplasia.