An association of a simultaneous nuclear and cytoplasmic localization of Fra-1 with breast malignancy
1 Institute of Basic Medical Sciences, Beijing 100850, P.R. China
2 307 Hospital, No. 8 East Street, Fengtai District, Beijing 100071, P.R. China
3 The Third Military Medical University, Chongqing 400038, P.R. China
4 The department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
BMC Cancer 2006, 6:298 doi:10.1186/1471-2407-6-298Published: 28 December 2006
Overexpression of Fra-1 in fibroblasts causes anchorage-independent cell growth and oncogenic transformation. A high level of Fra-1 expression is found in various tumors and tumorigenic cell lines, suggesting that Fra-1 may be involved in malignant progression. This study aimed to investigate the significance of Fra-1 expression in breast carcinogenesis.
The expression of Fra-1 was investigated by immunohistochemistry in neoplastic breast diseases ranging from benign fibroadenoma to very aggressive undifferentiated carcinoma. The correlations of Fra-1 expression with other indicators of breast carcinoma prognosis (ER, PR and ErbB2 receptors) were analyzed.
All neoplastic breast tissues, either benign or malignant breast tissues, were nuclear immunoreactive for Fra-1-recognizing antibody. The pattern of Fra-1 expression by benign neoplastic cells was predominantly nuclear. However, the nuclear/cytoplasmic concomitant immunoreactivity was observed in all types of breast carcinomas. A clear shift in Fra-1 immunoreactivity, from an exclusively nuclear to a simultaneous nuclear and cytoplasmic localization was noticed in ~90% of breast carcinomas.
The overall expression, pattern and intensity of Fra-1 proteins were correlated with breast oncogenesis. Overexpression of Fra-1, leading to a persistent high cytoplasmic accumulation, may play a role in the process of breast carcinogenesis.