Immunohistochemical study of Aquaporin-1, Cyclooxygenase-2 and Apoptosis Protease-Activating Factor-1 expression in breast cancers. Preliminary study

The aim of the present study is to establish possible associations between Aquaporin-1, Cyclooxygenase-2 and Apoptosis Protease-Activating Factor-1 expression in breast cancers and pathological and immunohistochemical characteristics of the examined tumors.

For the purpose of this study we used paraffin embedded archived tumor material of 31 breast cancer patients from the Pathology Department of the Odorheiu Secuiesc Municipal Hospital. We performed immunohistochemistry reactions ER, PR, HER2, AQP1, COX2 and APAF1, and following independent evaluation by two pathologists the obtained data was statistically analyzed. The tumors were divided into three groups based on their histological properties, and correlations were made with the examined markers.

AQP1, COX2 and APAF1 immunostaining results produced significant correlations with HER2 status and histological groups. There were no statistical correlations between ER or PR status and the three examined markers.

Lobular carcinomas showed AQP1 and COX2 overexpression, and loss of APAF1 expression, which all correlated with HER2 negative status.

We concluded that AQP1 could be a useful marker for detecting more aggressive subtypes and also for evaluating tumor angiogenesis. COX2 and APAF1 immunoexpression, although somewhat specific to certain histological groups, needs to be further characterized in order to be a useful marker for the clinical setting.