Tissue expression of the antiapoptotic protein survinin as a potential biomarker of prostate cancer

Abstract

Background. Excessive expression of survivin is associated with inhibition of cell death, activated by extrinsic or intrinsic apoptotic pathways. The survininin overexpression has been shown in various malignancies, including lung cancer, pancreatic and breast cancer, colon cancer, oral squamous cell carcinoma and high grade non-Hodgkin lymphomas.Aim. To investigate the level of survivin expression in prostate cancer tissues, and evaluate it as a diagnostic marker of prostate cancer.Materials and methods. The level of survivin expression and its subcellular localization were assessed immunohistochemically in patients with prostate cancer (n = 64) and benign prostatic hyperplasia (n = 33). Tissue samples obtained at transrectal biopsy were used for analysis. Prostate cancer samples obtained after cystprostatectomy in patients with normal prostate specific antigen level and normal ultrasound findings (n = 36) were considered control tissue (norm).Results. In prostate cancer group 3+ samples with a high level of survivin expression were present in 48.4 % of cases. In benign prostatic hyperplasia group the majority of samples were assessed as 2+, while 9.1 % of samples were negatively stained. 100 % of normal epithelium samples were negative. In patients with Gleason score <7 a survivin expression level was less than 3+ in 62.5 % of cases, and in patients with Gleason score >7 a highly positive reaction was detected in 68.8 % of cases. A high level of survivin expression was found in the large proportion of tissue samples at prostate specific antigen levels >10 ng/ml. Almost 50 % of highly positive cells were detected at a prostate health index (PHI) value of ≥60. The largest percentage of negative staining for surviving was common with PHI value <25. The degrees of staining for survining 1+ and 2+ prevailed in patients with prostate health index density (DPHI) <0.8, while a high level of prostate cells staining 3+ was observed at >0.8. As a Gleason score increase we observe the change of staining type for nucleocytoplasmic, and the largest number of samples has a staining degree of 2+ at a score GG4–5 (≥4 + 4). The type and frequency of prostate tissue samples staining were not differ depending on the initial prostate specific antigen level.Conclusion. Immunohistochemical assessment of the survivin level, including its subcellular localization, could be considered as tumor-associated and a potential biomarker for differential diagnosis and prediction of prostate cancer course.