Low LKB1 Expression Results in Unfavorable Prognosis in Prostate Cancer Patients

BACKGROUND The present study aimed to compare the expression of liver kinase B1 (LKB1) in prostate cancer (PCa) tissues and the paired adjacent tissues, then to evaluate the statistical relationship between LKB1 expression and prognosis of PCa patients. MATERIAL AND METHODS The relative expression of LKB1 at mRNA level was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of LKB1 at protein level was measured by immunohistochemistry (IHC) method. The relationship between LKB1 expression and clinicopathologic characteristics was estimated by chi-square test. Kaplan-Meier method was used to analyze the overall survival of PCa patients with different LKB1 expression. Cox regression analysis was performed to estimate the significance of LKB1 expression and clinicopathologic characteristics in the prognosis of PCa patients. RESULTS The relative expression of LKB1 at mRNA level was significantly lower in PCa tissues than in the normal tissues (P<0.001). The LKB1 expression was proved to be affected by clinical stage (P=0.019) and PSA concentration (P=0.031) of PCa patients. Moreover, patients with negative LKB1 expression had shorter survival than those with positive expression. Cox regression analysis confirmed that LKB1 could be regarded as a prognostic biomarker for PCa patients (P=0.001, HR=3.981, 95% CI=1.698-9.336). CONCLUSIONS The expression of LKB1 was lower in PCa tissues and might be a predictor for the prognosis of PCa patients.