Study On The Expression And Function Of PCA3 And The TMPRSS2_ERG Fusion Gene In Prostate Cancer

Objective: People’s awareness of the limitations and disadvantages of serum prostate-specific antigen(PSA) is more and more obviously, although there are many candidate indicators in diagnosis of prostate cancer, but really has potential clinical applications are extremely limited.This study was to explore that whether the joint detection of prostate cancer antigen 3(PCA3) and the fusion gene of transmembrane protease serines to ERG(TMPRSS2_ERG)in blood and urinary could improve the diagnostic accuracy of prostate cancer.Methods: From February 2014 to January 2015, 24 patients with prostate cancer and 51 patients without prostate cancer(43 patients with BPH and 8 cases with urinary stone)from Tangshan Gongren Hospital were taken the initial urine and venous blood specimens after prostate massage, and application of realtime fluores-cence quantitative PCR method for detection of relative expression level of PCA3 and the TMPRSS2_ERG fusion gene in blood and urinary. Used t-test statistical methods to analyze the correlation between its relative expression level and the prostate cancer, and record into the group of the patient’s age, PSA, prostate volume, biopsy results(Gleason score),risk group and clinical TNM staging, analysis that whether it has significant correlation with the relative expression level of PCA3 and TMPRSS2_ERG fusion gene.Results:1 The PCA3 and TMPRSS2_ERG fusion gene’s relative expression of m RNA in peripheral venous blood and urine after the prostate massage in prostate cancer group were significantly higher than that the non prostate cancer group, with the two independent samples t test statistical methods of statistical analysis, P=0.000, the difference between the two groups have statistical significance. And through the statistical analysis to the research groups of PSA in the level of 4 ~ 10 ng/ml and 10~20ng/ml, P values were all less than 0.05, it shows that even in the team of PSA in the grey area,PCA3 and TMPRSS2_ERG fusion gene were still diagnosis indicator of meaningful.2 The area under the ROC curve(AUC) of PCA3 m RNA relative expression in the diagnosis of prostate cancer in the urine after the prostate massage was 0.815(95% CI: 0.708 ~ 0.922), the optimal cutoff value of the diagnosis of prostate cancer was 0.92, at this cutoff value, the sensitivity and specificity were 62.5%(15/24)and 90.2%(46/51); The area under the ROC curve(AUC) of TMPRSS2_ERG m RNA relative expression in the diagnosis of prostate cancer was 0.762(95% CI: 0.708 ~ 0.922), the optimal cutoff value of the diagnosis of prostate cancer was 0.935, at this cutoff value, the sensitivity and specificity were 45.8%(11/24)and 92.2%(47/51).The area under the ROC curve(AUC) of PCA3 m RNA relative expression in the diagnosis of prostate cancer in the peripheral venous blood was 0.796(95% CI: 0.684 ~ 0.908), the optimal cutoff value of the diagnosis of prostate cancer was 1.42, at this cutoff value, the sensitivity and specificity were 54.2%(13/24)and 96.1%(49/51); The area under the ROC curve(AUC) of TMPRSS2_ERG m RNA relative expression in the diagnosis of prostate cancer was 0.708(95% CI: 0.708 ~ 0.922), the optimal cutoff value of the diagnosis of prostate cancer was 1.02, at this cutoff value, the sensitivity and specificity were 41.7%(10/24)and 96.1%(49/51).3 The joint detection of PCA3 TMPRSS2_ERG fusion gene in the urine after the prostate massage is the most widely studied joint model in nowadays. In this study, the AUC value of the joint detection is 0.816(95% CI: 0.697~0.935),its sensitivity was 66.7% at the best cutoff value, and it is slightly higher than the result of single detection of PCA3(urine). However, the AUC value was as high as 0.859(95% CI: 0.763 ~ 0.954)in the joint detection of PCA3 and TMPRSS2_ERG fusion gene in peripheral venous blood urine after the prostate massage, the sensitivity was even achieve to 75.0% at the optimal cutoff value, which is increased by 12.5% than the PCA3(urine) testing results.4 In this study, all groups of data were normally distributed by the single sample k- s inspection. Examined by the Pearson correlation analysis, there is no correlation between the relative expression level of PCA3 and TMPRSS2_ERG fusion gene in peripheral venous blood and urine after the prostate massage with the age, prostate volume, serum PSA and dangerous group in prostate cancer group and non prostate cancer group(P > 0.05),but it has a positive correlation with Gleason score and clinical stage(P < 0.05).Conclusion:PCA3 and TMPRSS2_ERG fusion genes are two kinds of diagnosis significance molecular markers to prostate cancer. The joint detection of PCA3 and TMPRSS2_ERG fusion gene in urine and blood can improve the diagnostic sensitivity of prostate cancer significantly. At the same time, there was no significant correlation between the two kinds of molecular markers with the patients’ age, prostate volume, PSA in the serum and the risk group,but it has significant correlation with the Gleason score and clinical staging of the prostate cancer.Combined detection of PCA3 and TMPRSS2_ERG fusion gene in peripheral blood and urinary can diagnose prostate cancer noninvasively and efficiently, it has a good clinical value of promotion.