Abstract: Background and purpose: P38 mitogen-activated protein kinase (P38MAPK) signal transduction pathway is involved in occurrence, development and transfer process in a wide variety of tumors. Urokinase-type plasminogen activator (uPA) plays an important role in tumor invasion and metastasis. This study aimed to explore the clinical significance of the P38MAPK signaling pathway and the expression of uPA in ovarian cancer. Methods: The expressions of uPA, P38MAPK, ERK and AKT were detected in 49 cases of cervical adenocarcinoma by immunohistochemistry. The expressions of uPA and P38MAPK were detected by Western blot in ovarian cancer cell lines HO8910, HO-8910PM, SKOV3 and CAOV3. The changes of uPA and P38MAPK were detected by SB203580, a specific inhibitor of P38MAPK signal transduction pathway. Results: The result of immunohistochemical method showed that positive expression rates for uPA, P38MAPK, ERK and AKT were 61.22%, 57.14%, 53.06% and 55.10%, respectively. The expression of the uPA was positively correlated with the P38MAPK (r=0.865, P=0.001), and related with clinicopathologic stage, differentiated degree, lymph node metastasis, but not related with age and histologic type (P>0.05). The expressions of AKT and ERK were related with the lymph node metastasis and greater omentum metastasis (P<0.05), but not related with age and histologic type (P>0.05). The expression of uPA in HO-8910PM was higher than that in ovarian cancer cell lines HO8910, SKOV3 and CAOV3, and the expression of uPA reduced when the P38MAPK signal transduction pathway was cut off by the SB203580. The expressions of P38MAPK and uPA were negatively correlated with the prognosis of ovarian cancer (Log-rank=3.897 and 11.044, P=0.048 and 0.001). Conclusion: The P38MAPK signal transduction pathway was activated in ovarian cancer. The activated P38MAPK signal transduction pathway can raise the expression of uPA, which may contribute to the development of ovarian cancer. The result indicates that the P38MAPK signal transduction pathway and uPA might play an important role in the invasion and metastasis of ovarian cancer. P38MAPK and uPA might be useful markers for evaluating prognosis of ovarian cancer.

Key words: Ovarian cancer, Urokinase-type plasminogen activator, Extracellular signal-regulated kinase, Serine threonine kinase, P38 mitogen-activated protein kinase signal transduction pathway