Breast cancer is the leading cause of cancer-related deaths in women worldwide yearly. Although surgical treatment, adjuvant therapies with hormones and chemotherapy have been used for the treatment of breast cancer, new therapeutic approaches are needed to reduce its high recurrence rate. Immunotherapy aimed at recruiting the host's immune system to identify and destroy aberrant tumor cells maybe a useful method. Furthermore, successful development of immunotherapeutic breast cancer vaccines hinges on the identification of appropriate target antigens, especially the cancer/testis antigen.
Taxol resistance-associated gene-3 (TRAG-3) is a novel cancer/testis antigen 2 initially discovered when comparing ovarian cell line SKOV-3 to SKOV-3TR by differential display in the search for new genes. 3 This antigen is highly expressed in melanoma 2 and nonsmall cell lung carcinoma. 4 We report for the first time to our knowledge that TRAG-3 also is overexpressed in most human breast cancer, which suggests TRAG-3 could be a potential target for immunotherapy in breast cancer.
Thirty-four tumor samples and one normal breast tissue sample were collected during routine surgery performed at Southwest Hospital, Chongqing, China. The median age of the patients was 51 years. Histologic examination of the tumors revealed 8 invasive lobular carcinoma, 2 carcinoma simplex, 2 medullary carcinoma and 22 invasive ductal carcinoma according to the WHO classification of cancer.
RT-PCR was used to analyze the TRAG-3 mRNA expression in the breast cancer tissue specimens (Table ). Total RNA was prepared from frozen tissues with TRIzol Reagent (GIBCO, Carlsbad, CA) according to the manufacturer's protocol. The commercially synthesized primers were sense 5Π-