Abstract

BACKGROUND
The E2F family (E2F1 to E2F6) of transcription factors plays a key role in cell cycle progression. Some act as oncogenes and others act as tumor suppressor genes (TSG) in a tissue-specific manner. E2F4 may function as a TSG. However, the role of E2F4 in breast carcinogenesis remains controversial. Also the clinical impact of E2F2 expression on breast cancer remains unknown.
METHODS
Expressions of E2F4 and E2F2 were assessed immunohistochemically in 113 breast carcinomas and were compared with clinicopathological variables, expressions of G1/S checkpoint proteins (p16, cyclin D1 and Rb), and DNA ploidy to identify their possible role and to assess their prognostic value in breast cancer.
RESULTS
Expressions of E2F4 and E2F2 were detected in 48 cases (42.5%) and 66 cases (58.4%), respectively. Expressions of E2F4 and E2F2 were significantly correlated with large tumor size (p<0.001) and lymph node metastasis (p<0.001). There was no correlation between expressions of E2F4 or E2F2 and any other variables, including age, histologic grade, DNA ploidy and expressions of p16, cyclin D1 and Rb.
CONCLUSIONS
These results suggest that expressions of E2F4 and E2F2 are associated with growth and spread of breast cancer and indicate poor prognosis.

• Keywords: Breast cancer;E2F4 transcription factor;E2F2 transcription factor;Immunohistochemistry;