Objective:To study the expression level of pyruvate dehydrogenase kinase 1(PDK1)in ovarian cancer(OC)tissues and its correlation with clinicopathological characteristics and prognostic factors. Methods:Real time PCR was used to detect the mRNA expression of PDK1 in ovarian cancer cell line SKOV3 and human ovarian epithelial cell line HOSEpiC. Real time PCR was used to detect the mRNA expression levels of PDK1 in patients with benign ovarian tumor(BOT)and ovarian cancer. Immunohistochemistry was used to detect the expression of PDK1 in ovarian benign tumors and ovarian cancer tissues. Univariate and multivariate logistics regression analysis was used to analyze the relationship between PDK1 expression and OC clinicopathological characteristics,and survival analysis was performed by Kaplan-Meier. Results:The average expression level of PDK1 mRNA in the ovarian cancer cell line SKOV3was significantly higher than that of human ovarian epithelial cell line HOSEpiC(t=38.60,P<0.001). The average expression level of PDK1 mRNA in ovarian cancer tissues was significantly higher than that in ovarian benign tumor tissues(t=2.411,P=0.022). The immunohistochemical staining showed that the average expression level of PDK1 protein in the ovarian cancer tissue was significantly higher than that of the benign ovarian tumor tissue(χ2=33.874,P<0.001). The high expression of PDK1 was obviously associated with lymph node metastasis by univariate and multivariate logistics regression analysis,and had no significant correlation with age,tumor size,tumor differentiation,unilateral bilateral onset,and the completeness of the envelope. Furthermore,lymph node metastasis is an independent risk factor affecting PDK1 expression in ovarian cancer tissues. Patients with high expression of PDK1 had poor prognosis(χ2=4.455,P=0.035). Conclusion:PDK1 is highly expressed in ovarian cancer tissue,as an inhibitory enzyme of pyruvate dehydrogenase(PDH),PDK1 is involved in the process of tumor cell metabolism and recombination,and may play a pivotal role in the progress of ovarian cancer. It also can be used as a reference index to judge the poor prognosis of ovarian carcinoma.