The Expression Of β-2-Microglobulin And Its Correlation With PSA,Gleason Score In Prostate Cancer Pre- And Post-endocrine Therapy

Objective:To investigate the expression ofβ-2-Microglobulin(B2M) in prostate cancer patients before and after treatment, and the relationships between 02-M and serum prostate specific antigen (PSA) or Gleason score.Methods:The expression of B2M in supernatant of normal prostate cancer cell lines RWPE2 and androgen-independent cell lines PC-3,DU-145 were detected by radioimmunoassay. The expression of B2M,PSA and their correlation were observed after PC-3, DU-145 treated with androgen and bicalutamide respectively. Serum samples were collected from 15 cases of prostate cancer,15 cases of benign prostatic hyperplasia and 15 cases of health volunteers, radioimmunoassay was used to measure B2M and PSA levels in serum, and analyse their correlation in prostate cancer patients pre- and post-treatment.15 cases of prostate cancer tissues were stained with H&E, the correlation between serum B2M or PSA and the Gleason score were analyzed.Results:1. Compared with the normal prostate cancer cell lines RWPE2, B2M in androgen-independent prostate cancer cell lines PC-3, DU-145 were significantly increased (p<0.05). The expression of B2M and PSA in cell supernatant were obviously reduced (p<0.05) after PC-3, DU-145 treated with bicalutamide. Pearson correlation analysis demonstrated that there was a significant positive correlation between B2M and PSA (r1= 0.699, r2= 0.944, P<0.01).2. Serum B2M, PSA of 15 cases of prostate cancer were significantly higher than benign prostatic hyperplasia group and health control (P<0.05), but there was no obvious difference between benign prostatic hyperplasia group and normal group (P>0.05). There exists an obvious positive correlation between PSA and serum B2M using Pearson correlation analysis(r= 0.955, P< 0.01).Serum B2M and PSA were decreased at 1,3,6 months after treatment in prostate cancer patients, and they were significantly declined at 6 months after treatment. Pearson correlation analysis showed that there was a significant positive correlation between serum B2M and PSA after one months treatment (r=0.780, P<0.01).3. Pearson correlation analysis showed that there was a significant positive correlation between serum B2M,PSA and the Gleason score (r1=0.867, P<0.01; r2=0.764, P<0.01).Conclusion:1. The expression of B2M in prostate cell lines and patients with prostate cancer is increased, and there is a significant positive correlation between the level of B2M and the level of PSA. For serum B2M, there is no significant difference between benign prostatic hyperplasia group and health control.2. After treated prostate cancer patients with hormonal therapy which in patients without metastasis, Serum B2M levels was reduced. however, in patients with metastasis, Serum B2M was significantly elevated.3. B2M has a close relation with the progress of prostate cancer. There is a significant positive correlation between serum B2M and Gleason score of prostate cancer.4. Serum B2M is an important tumor marker for the diagnosis and monitoring recurrence of prostate cancer, and if combined with PSA, the level of diagnosis and prognosis of prostate cancer would be improved.