[Expression of TNF-like weak inducer of apoptosis (TWEAK) and its relationship to microvessel density in breast cancer].

Background & Objective: The expression of TNF-like weak inducer of apoptosis (TWEAK) in breast cancer remains disputable. This study was to investigate the expression of TWEAK in breast cancer tissues and breast cancer cell lines with different invasive abilities, and the relationship of TWEAK with microvessel density (MVD).

Methods: Immunohistochemical S-P method was adopted to detect the expression of TWEAK in 70 specimens of breast cancer and 30 specimens of adjacent normal breast tissues. The protein expression of TWEAK was determined by Western blot in a poorly invasive breast cancer cell line MCF-7 and a highly invasive breast cell line MDA-MB-231. Secretion of TWEAK was measured by ELISA assay in MCF-7 and MDA-MB-231 cells.

Results: The expression of TWEAK was higher in breast cancer (60%) than in adjacent normal breast tissues( 6.67%) (P<0.05), and is higher in infiltrating ductal carcinoma of the breast (76.67 %) than in breast ductal carcinoma in situ (42.85%) (P=0.003). MVD was higher in infiltrating ductal carcinoma of the breast than in breast ductal carcinoma in situ (P<0.05). The expression of TWEAK was significantly correlated with MVD in infiltrating ductal carcinoma of the breast(r=0.611), but not with breast ductal carcinoma in situ (r=0.015). The expression of TWEAK and secretion of soluble TWEAK were higher in MDA-MB-231 cells than in MCF-7 cells (t=4.259, P=0.007; t=3.6504, P=0.006 ).

Conclusion: TWEAK expression is related to the metastatic ability of breast cancer.