Background: The UNI antigen (Ag) is a 120 kDa sialoglycoprotein which has been primarily found in human undifferentiated CD3dim thymocytes and leukemic T-cell lines, but subsequently also detected in solid tumors. We studied the expression of this Ag in a panel of normal and pathological breast tissues.
Materials and methods: Analysis of UN1 Ag expression on tissue specimens was performed by immunohistochemistry and Western blotting.
Results: No Ag expression was found in 14 sections of normal tissue and 10 sections of benign nonproliferative lesions. Progressively increasing levels of UN1 Ag expression were found in fibroadenomas (24 positive out of 27 cases), proliferative lesions (9 cases), in situ (17 cases) and invasive carcinomas (56 cases). Finally, the highest expression was observed in 10 metastatic lesions.
Conclusion: These data suggest that UN1 Ag is a promising marker of potential value for immunophenotyping studies and therapeutic applications in breast diseases.