Background & objective: The researches about the expression of tumor necrosis factor receptor-associated factor 4 (TRAF4) in breast cancer are disputable. This study was to investigate the expression of TRAF4 in normal breast, breast carcinoma tissue, and cell lines with different invasive abilities.
Methods: The expression of TRAF4 in 70 specimens of breast carcinoma and 14 specimens of normal breast tissues was detected by SP immunohistochemistry. The expression of TRAF4 in breast cancer cell lines, MDA-MB-231 with high invasive ability and MCF-7 with low invasive ability, was detected by Western blot.
Results: TRAF4 was expressed both in cell cytoplasm and nuclei in normal breast tissues. The cytoplasmic positive rates of TRAF4 were 78.57% in normal breast tissues, 88.57% in non-invasive ductal carcinoma, and 91.43% in invasive ductal carcinoma (P>0.05). The nuclear positive rate of TRAF4 was significantly higher in normal breast tissues than in non-invasive ductal carcinoma (64.28% vs. 28.57%, P<0.01), and higher in non-invasive ductal carcinoma than in invasive ductal carcinoma (28.57% vs. 5.70%, P<0.05). The protein level of TRAF4 was slightly higher in MDA-MB-231 cells than in MCF-7 cells (P>0.05).
Conclusion: The nuclear expression of TRAF4 in breast carcinoma is suppressed, and correlated to the invasive ability of breast cancer.