Correlation between Expression of P38 MAPK-Signaling and uPA in Breast Cancer

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 a er treatment with SB203580,a specific 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 metastas is 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.