Identification and Characterization of Tumor Antigens Associated with Breast Cancer

Abstract : Recently, identification of tumor-associated antigens (TAAs) have led to an increased interest in vaccination strategies to treat cancer and/or prevent cancer relapse. Immunotherapy can be used as an adjuvant with other systemic therapy to target micro-metastatic disease and prevent cancer recurrence. Although preclinical/clinical trials using identified tumor-associated antigen for tumor vaccination are ongoing in melanoma and other cancers, breast cancer immunotherapy is limited, due to the limited numbers of breast tumor-associated antigens identified to date. Previously, three candidate breast tumor-associated antigens were identified in our lab by serological analysis of recombinant cDNA expression libraries (SEREX) derived from primary breast tumor and breast cancer cell lines (2-1-1, 7-3 and s3.2) . Initial characterization of these candidates by northern blot analysis revealed that 2-1-1 expression is tumor-specific while s3.2 clone is over-expressed in tumor. Although the expression of clone 7-3 is not restricted, its immunoreactivity is positive in high proportion of breast cancer patient sera (7/l4) . The evaluation of these putative tumor-antigens at the molecular level as well as further evaluation of their immunogenicity may provide insight in breast tumor biology as well as additional targets for breast cancer immunotherapy.