ACTA ENDOCRINOLOGICA (BUC)

Previous studies have correlated the expression of PAR proteins with breast cancer invasiveness. The scope of this study was to evaluate the expression of PAR-1 in human breast cancer specimens and investigate possible correlations with tumor size, grade and lymph node status, as well as covariations with estrogen and progesterone receptors, c-erbB-2 protein and lysosomal protease Cathepsin D. Formalin-fixed paraffin-embedded sections of 75 mastectomy specimens deriving from patients with primary breast carcinomas were implemented. Expression of PAR-1 was detected employing immunohistochemical assays utilizing a goat polyclonal PAR-1 antibody. The granular pattern of cytoplasmic immunoreaction was considered indicative for the protein?s expression. Statistical assessment was performed using SPSS 13.0 statistical package, Pearson?s correlation, &#967;2 and Fisher?s exact test. Expression of PAR-1 protein had a statistically significant correlation (p<0.001) with tumor grade, while in invasive tumors a similar relationship (p<0.001) was documented between PAR-1 expression and presence of positive axillary lymph nodes. However, PAR-1 expression did not exhibit a significant correlation with tumor size or with the expression of ER, PR, c-erbB-2, or Cathepsin D molecules. PAR-1 possesses a role in tumor invasion and contributes to the metastatic potential of certain types of breast carcinomas. The disassociation between expression of PAR-1 and that of the ER, PR, c-erbB-2, or Cathepsin D might imply participation in alternative pathways of malignant transformation and tumor progression.