Apolipoprotein A-II Isoform As A Biomarker For Prostate Cancer

• US 20080248500A1
• Filed: 01/06/2006
• Published: 10/09/2008
• Est. Priority Date: 01/06/2005
• Status: Active Grant

• Current Assignee: Eastern Virginia Medical School
• Original Assignee: Eastern Virginia Medical School
• Inventors: Ward, Michael D., Malik, Gunjan, Semmes, O John
• Granted Patent: US 7,811,772 B2
• Time in Patent Office: Days
• US Class Current: 435/7.23
• 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 determining prostate cancer status in a subject comprising the steps of:

(a) providing a biological sample from the subject;

(b) contacting the biological sample with a biospecific capture reagent capable of capturing 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, whereby the ApoA-II isoform is bound to the biospecific capture reagent;

(c) determining the amount of the bound ApoA-II isoform; and

(d) correlating the amount of the bound ApoA-II isoform to prostate cancer status.

2. The method of claim 1 wherein the prostate cancer status is prostate cancer versus normal.

3. The method of claim 1, wherein the prostate cancer status is prostate cancer versus benign prostate hyperplasia.

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

5. The method of claim 1, wherein the prostate cancer status is determined as part of determining susceptibility of the subject to prostate cancer.

6. The method of claim 1, wherein the prostate cancer status is determined as part of determining the stage or severity of prostate cancer in the subject.

7. The method of claim 1, wherein the prostate cancer status is determined as part of identifying a risk for the subject of developing prostate cancer.

8. The method of claim 1, wherein the prostate cancer status is determined as part of monitoring the effect of an anti-prostate cancer drug or a therapy administered to the subject diagnosed with prostate cancer.

9. The method according to claim 1, wherein the biological sample is a human physiological fluid.

10. The method according to claim 9 wherein the human physiological fluid is whole blood or serum.

11. The method according to claim 1, wherein the biological sample is a human prostate tissue sample.

12. The method according to claim 11, wherein the human prostate tissue sample is a prostate cancer tissue sample or a benign prostate hyperplasia tissue sample.

13. The method according to claim 1, wherein the biospecific capture reagent is attached to a solid support.

14. The method according to claim 13, wherein the solid support is a mass spectrometry probe and the biospecific capture reagent comprises an antibody attached to the probe and wherein step (c) comprises detecting the bound ApoA-II isoform by laser desorption-ionization mass spectrometry.

15. The method according to claim 1, wherein the biospecific capture reagent is an antibody selected from the group consisting of polyclonal antibodies, monoclonal antibodies, bispecific antibodies, human antibodies, humanized antibodies, chimeric antibodies, single chain antibodies, and active fragments thereof.

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

(e) comparing the amount of the ApoA-II isoform in the biological sample with the amount of an ApoA-II isoform 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 in subjects free from prostate cancer.

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

(e) contacting the biological sample with a biospecific capture reagent capable of capturing a prostate cancer-specific biomarker X, wherein the prostate cancer-specific biomarker X is different from the ApoA-II isoform.

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

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

20. The method according to claim 19, wherein PAGE is 2-dimensional PAGE.

21. A it for determining prostate cancer status, the kit comprising:

(a) a solid support comprising at least one biospecific capture reagent attached thereto, wherein the at least one biospecific capture reagent is capable of capturing 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

(b) instructions for using the solid support to detect the ApoA-II isoform.

22. The kit of claim 21, wherein the solid support comprising the biospecific capture reagent is a SELDI probe.

23. The kit of claim 21, further comprising:

(c) a container containing the ApoA-II isoform.

24. The kit of claim 21, further comprising:

(c) a biospecific capture reagent capable of capturing a prostate cancer-specific biomarker X, wherein the prostate cancer-specific biomarker X is different from the ApoA-II isoform.

25. A kit for determining prostate cancer status, the kit comprising:

(a) a solid support comprising at least one biospecific capture reagent attached thereto, wherein the at least one biospecific capture reagent is capable of capturing 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

(b) a container containing the ApoA-II isoform.

26. The kit of claim 25, wherein the solid support comprising the biospecific capture reagent is a SELDI probe.

27. A kit for determining prostate cancer status, the kit comprising:

(a) an antibody capable of binding to 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;

(b) reagents for PAGE and Western blotting; and

(c) instructions for using the antibody to detect the ApoA-II isoform.

28. A software product for classifying a prostate cancer status, the software comprising:

(a) a code that accesses data attributed to a biological sample, the date comprising measurement 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

(b) a code that executes a classification algorithm that classifies the prostate cancer status of the biological sample as a function of the measurement.

29. A method comprising the step of:

(a) communicating to a subject a diagnosis relating to prostate cancer status determined from the correlation of an ApoA-II isoform in a sample from the subject, 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.

30. The method of claim 29, wherein the diagnosis is communicated to the subject via a computer-generated medium.

31. A purified biomolecule comprising:

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

1); and

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

2);

and wherein the purified biomolecule has a molecular weight of about 8943 Dalton ±

15.

32. A method for determining prostate cancer status in a subject comprising the steps of:

(a) providing a biological sample 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 prostate cancer status.