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


CONCLUSIONS
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.
Song
Yuhua
Y
Institute of Basic Medical Sciences, Beijing 100850, PR China. qdsongyh@163.com <qdsongyh@163.com>
Song
Santai
S
Zhang
Dong
D
Zhang
Yan
Y
Chen
Liyong
L
Qian
Lu
L
Shi
Ming
M
Zhao
Huibin
H
Jiang
Zefei
Z
Guo
Ning
N
D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics* / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000378:metabolism; D000099169:Fos-Related Antigen 1
D016760:Proto-Oncogene Proteins c-fos; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D000099169:Fos-Related Antigen 1