Expression of speckle-type poxvirus and zinc finger protein in prostate cancer

Abstract

Objective To explore the expression of speckle-type poxvirus and zinc finger (POZ) protein (SPOP) in normal prostate (NP), benign prostate hyperplasia (BPH), pericancerous (PC) tissue and prostate cancer (PCa), and study its correlation with the grade and stage of PCa. Methods Totally 12 NP slides, 12 BPH slides, 12 PC slides and 46 PCa slides from our hospital were collected. These slides were routinely processed and analyzed according to the requirement of immunohistochemical staining. Tumors were classified according to the 2002 TNM staging system. The grading system used was based on the Gleason grade. Results We found that the expression of SPOP in PCa (28/46) was significantly lower than that in NP (12/12, P=0.009), BPH (11/12, P=0.009) and PC (12/12, P=0.009) tissue, and the difference was statistically significant (P<0.05). With regard to grade of PCa, the expression of SPOP in PCa with Gleason score ≥8 group (2/11) was lower than the Gleason score 2-4 group (9/12, P=0.006) and the Gleason score 5-7 group (17/23, P=0.002). The difference was statistically significant (P<0.05). Moreover, the T3 (4/11) and T4 (4/12) stages had a less positive rate than the T1 (6/7) and T2 (14/16) stages. There was statistically significant difference between early and advanced stage of PCa (P=0.000). Furthermore, the positive expression of SPOP in PCa samples decreased significantly in the metastasis group (3/12, P=0.003). Conclusion SPOP may be related to the development of PCa and the expression of SPOP in PCa correlates with the grade and stage of PCa. Key words: Prostate cancer; Speckle-type poxvirus and zinc finger protein; Gleason score