Increased expression of Golgi phosphoprotein-3 is associated with tumor aggressiveness and poor prognosis of prostate cancer

BACKGROUND To investigate the expression of Golgi phosphoprotein-3 (GOLPH3) in prostate cancer and determine its prognostic value. METHODS Immunohistochemical staining for GOLPH3 was performed on tissue microarrays of 342 prostate patients. The correlation between GOLPH3 expression with its clinicopathologic factors was also analyzed in order to determine its prognostic significance. RESULTS GOLPH3 expression of normal prostate tissues, benign prostate hyperplasia, high-grade prostatic intraepithelial neoplasia, and hormone-dependent prostate cancer (HDPC) did not show any statistically significant difference. In contrast, statistically significant difference was reported in moderate/intense GOLPH3 expression in cases diagnosed with HDPC and castration resistant prostate cancer (CRPC) (P < 0.0005). Moderate /intense expression of GOLPH3 was associated with androgen independence (P = 0.012), higher Gleason score (P = 0.017), bone metastasis (P = 0.024), higher baseline prostate-specific antigen (PSA) (P = 0.038), and higher PSA nadir (P = 0.032). A significantly negative correlation was found between moderate/intense GOLPH3 expression and disease-free survival (DFS) (HR = 0.28, P = 0.012) and overall survival (OS) (HR = 0.42, P = 0.027). Univariated analysis indicated that moderate/intense GOLPH3 expression created a significantly prognostic impact in patients with CRPC. On the other hand, multivariate analysis indicated that GOLPH3 was a significantly independent prognostic factor of DFS (P = 0.027) in all prostate cancer patients. CONCLUSIONS In this study, it was discovered that the overexpression of GOLPH3 is associated with the transition of prostate cancer from hormone sensitive phase to hormone refractory phase. GOLPH3 might be an important prognostic factor of DFS and OS in patients with prostate cancer. In totality, GOLPH3 could be used as a novel candidate in devising a more effective therapeutic strategy to tackle CRPC. VIRTUAL SLIDES The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1452541171722856.