Clinical Study Of The Correlation Between PSA MRNA In Prostate Tissue And Serum PSA

Objective:To investigate the changes of PSA mRNA expression levels in benign prostatic hyperplasia(BPH)and carcinoma(PCa)tissues and to explore the correlation between peripheral blood prostat-specific antigen(PSA)levels and PSA production ability in benign and malignant prostate tissues.Material methods:We prospectively evaluated 83 consecutive patients underwent 12 core transrectal ultrasound(TRUS)-guided prostate biopsies between December 2015 and June 2016 in our hospital,according to the pathological diagnosis was divided into 51 patients with benign hyperplasia,and 32 patients with prostatic malignant neoplasm.The distribution of prostatic malignant neoplasm patients were 7 had Gleason score 6 patients,21 had Gleason score 7-8 and 4 had Gleason score 9-10;Clinical data were obtained including age,prostate volume,serum PSA and Prsotate Specific Antigen Density(PSDA).All biopsy tissues were divided into two groups including 617 benign hyperplasia cases and 112 malignant cases.According to the Gleason classification,all malignant tissues were divided into 3 groups:Gleason score 6,Gleason score 7-8 and Gleason score 9-10.The expression levels of PSA mRNA and GAPDH were measured by Real-Time RT-PCR,and the relative expression levels of PSA mRNA were calculated by the formula1000*2-△CT.The SPSS software was applied for data analysis.Mann-Whitnsy U test was used to compare the differences of levels of serum PSA and relative expression of tissue PSA mRNA between different groups;Binomial Logistic regression was used to calculate and compare the relative risk(OR)of PSA mRNA in different prostate Gleason grades,and analyze the application value of PSA mRNA relative expression in predicting the severity of prostate cancer;and Spearman test was used to analyze the correlation between serum PSA level and tissue PSA mRNA relative expression in PCa patients and BPH patients;Multiple linear regression was used to analyze the related factors of elevated tPSA level in BPH patients.Results:1.The median serum tPSA levels in PCa patients and BPH patients were 10.1(6.3-18.6)ng/ml and 8.0(5.9-11.9)ng/ml,respectively.The tPSA levels in PCa patients were significantly higher than those in BPH patients(P=0.002).Different Gleason scores of PCa patients were positively correlated with serum tPSA level(r=0.464,P=0.009).2.The median relative expression levels of PSA mRNA in PCa and BPH tissues were 2242.48(202.71-9730.08)and 2138.47(269.22-8254.61),respectively.The relative expression levels of PSA mRNA in PCa tissues were higher than BPH tissues,but there was no statistically significant difference(P=0.632).The relative expression levels of PSA mRNA in groups of Gleason score 6,Gleason score 7-8 and Gleason score 9-10 were 2440.10(186.75-16348.21),6271.24(519.24-10506.72)and 2138.47(269.22-8254.61),respectively.Compared with the BPH group,the relative expression of PSA mRNA in the group with Gleason score 9-10 was significantly decreased(P=0.014),while the relative expression of PSA mRNA in the group with Gleason score 7-8 was significantly higher than that in the BPH group(P=0.048).The relative expression level of PSA mRNA in the group of Gleason score 9-10 was also significantly lower than that in the group of Gleason score 7-8(P=0.002).3.The relative risk OR(95%CI)of gleason9-10 in the PCa group with the lowest relative expression of PSA mRNA was 7.22(1.77-29.56)compared with the highest group.4.There was no statistically significant difference between PCa and the benign hyperplasia tissues in the same patient.No correlation between the relative expression of PSA mRNA and Gleason score was found in the same patient.5.There was no correlation between the relative expression of PSA mRNA and the level of serum tPSA in PCa and BPH patients.6.Serum tPSA level was positively correlated with prostate volume in BPH patients(Beta=0.432,P=0.002),and positively correlated with inflammation(Beta=0.415,P=0.001).Conclusion:Our results suggest that there was no significant difference in PSA production capacity between BPH tissue and PCa tissue,but the PSA production capacity of moderately differentiated prostate tissue was significantly higher than that of BPH tissue,while that of low-differentiated prostate cancer tissue was significantly lower.There was no correlation between PSA levels and PSA production capacity in peripheral blood.Detection of PSA mRNA expression can be used to predict highly malignant prostate cancer.Prostate volume and inflammation were independent factors affecting tPSA levels in BPH patients.