Expression of Prostate Apoptosis Response (Par-4) Is Associated with Progesterone Receptor in Breast Cancer
Received 24 October 2008; accepted 31 July 2009.
Background
The prostate apoptosis response (Par-4) gene encodes a proapoptotic protein that selectively induces apoptosis in cancer cells after diverse apoptotic stimuli. Par-4 expression and its association with other biomarkers have not been reported in breast cancer. The purpose of this study was to determine Par-4 expression in breast cancer samples and its association with other biomarkers and clinical factors (T-stage, age, nodal status).
Methods
Paraffin-embedded section samples of breast cancer were evaluated by immunohistochemical analysis to determine Par-4, estrogen receptor (ER), progesterone receptor (PgR), c-erbB2, Ki67, p53 and bcl-2 expression. The correlation between Par-4 and the other biomarkers and clinical factors was determined by multivariate analysis.
Results
Thirty five percent (n=21) of samples were PAR-4 positive and 64.4% (n=38) were negative. The hormonal status was 64% ER positive (n=38), 35% ER-negative (n=21) and 40.7% PgR positive (n=24), 59.3% PgR negative (n=35). The majority (90%) of the samples presented clear cytoplasmic localization and a small portion (10%) was cytoplasmic and nuclear. Univariate analysis indicates that the Par-4 expression has a significant inverse association (p=0.04) only with expression of PgR and not with the other variables analyzed. Normal breast tissue analyzed was negative for Par-4 immunostaining.
Conclusions
Our results suggest that, in breast cancer, Par-4 plays a similar tumor suppressor gene role as reported in endometrial carcinoma
aDepartamento de Inmunología y Virología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
bLaboratorio de Anatomía Patológica, Hospital Christus Muguerza, Monterrey, Nuevo León, México
Address reprint requests to: Cristina Rodriguez-Padilla, Pedro de Alba S/N, San Nicolás de los Garza, 66450 Nuevo León, México; FAX: (+52) (81) 8352-4212
ABSTRACT