An association of a simultaneous nuclear and cytoplasmic localization of Fra-1 with breast malignancy

Yuhua Song¹^,2^,4 , Santai Song² , Dong Zhang² , Yan Zhang¹^,3 , Liyong Chen¹ , Lu Qian¹ , Ming Shi¹ , Huibin Zhao² , Zefei Jiang² and Ning Guo¹

¹Institute of Basic Medical Sciences, Beijing 100850, P.R. China

²307 Hospital, No. 8 East Street, Fengtai District, Beijing 100071, P.R. China

³The Third Military Medical University, Chongqing 400038, P.R. China

⁴The department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China

author email corresponding author email

BMC Cancer 2006, 6:298doi:10.1186/1471-2407-6-298


Published:	28 December 2006

Abstract

Background

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.

Methods

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.

Results

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.

Conclusion

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.