BACKGROUND:  Prostate cancer is the most common cancer in men in the United States, rendering it the second-leading cause of cancer-related death in men. Early detection is key for ensuring a successful course of treatment. Prostate specific antigen (PSA) tests have decreased mortality, but lack the ability to differentiate between malignant and non-malignant cases. Molecular identification of tumor-associated antigens (TAA) has clearly demonstrated that this differentiation can be achieved. Of particular interest to the serological analysis of human cancers is the identification of TAA recognized by antibodies. Investigating antibody responses against a large panel of TAA that covers a wide spectrum of subjects with a particular cancer, such as prostate cancer, requires the purification of individual TAA proteins, which is expensive and difficult to achieve. Therefore, a need exists for epitopes of TAA, smaller protein sequences capable of binding to the desired antibodies, for the detection of antibodies against these antigens.

INNOVATION:  Researchers at UCLA have identified several B cell peptide epitopes from a panel of prostate cancer-associated antigens (PCAA). These epitopes are capable of binding antibodies against PCAAs, rendering them useful biomarkers for prostate cancer.

POTENTIAL APPLICATIONS 

• Prostate cancer diagnostics
• Monitoring of cancer progression
• Evaluation of treatment efficacy
• Differentiation between malignant and non-malignant cases

ADVANTAGES

• Does not require individual TAA protein purification
• Synthetic peptides are easier to manipulate than purified recombinant TAA

DEVELOPMENT-TO-DATE:  Several novel peptide epitopes for the detection of antibodies against prostate cancer-associated antigens (PCAA) have been identified. Work continues to identify more epitopes that are useful as biomarkers for prostate cancer.

Reference: UCLA Case No. 2009-047