161Clin Oncol Cancer Res (2008) 5:161~164 Correlation between Expression of P38 MAPK-Signaling and uPA in Breast Cancer DOI 10.1007/s11805-008-0161-9

OBJECTIVE To study the expression of phosphorylated p38 mitogen-activated protein kinase (p-p38) and uPA and the correlation of their expression with breast cancer clinicopathological characteristics, and to investigate the role of the p38MAPK-signaling pathway in regulating uPA expression in breast cancer cells. METHODS Immunohistochemistry (S-P) was used to test the expression of p-p38 and uPA in 60 specimens of breast cancer tissues. Western blots were adopted to detect expression of the p-p38 and uPA proteins in MDA-MB-231 and MCF-7 breast cancer cells, and uPA expression aĞ er treatment with SB203580, a specifi c inhibitor of p38 MAPK. RESULTS The positive rate of the p-p38 protein and uPA protein expression in the breast cancer tissues was 56.7 % and 60.0%,respectively. The expression of p-p38 was positively related to the expression of uPA (r = 0.316, P < 0.05). The expression of p-p38 and uPA was related to lymph node metastasis and the TNM stage (P < 0.05), but it was not related to the patient’s age or tumor size (P> 0.05). The expression of p-p38 and uPA in MDA-MB-231 cells was higher than that in MCF-7 cells. SB203580 inhibited the p38 MAPK pathway and reduced uPA protein expression. CONCLUSION The p38 MAPK-signaling pathway promotes breast cancer malignant progression by up-regulating uPA expression,and it may be an important process in breast cancer invasion and metastasis