VICKZ2 protein expression in ovarian serous carcinoma effusions is associated with poor survival

SummaryThe involvement of VICKZ proteins has been implicated in a large number of cancers. The aim of the present study was to investigate the biological and clinical role of VICKZ proteins in ovarian carcinoma (OC). VICKZ1-3 protein expression was analyzed in 82 serous OC specimens (51 effusions, 14 primary carcinomas, 17 solid metastases) by immunoblotting. Protein localization was studied using immunohistochemistry in 101 tumors (40 effusions, 25 primary carcinomas, 36 solid metastases). The effect of VICKZ silencing using short hairpin RNA on collagenolytic activity and invasion was assessed in ES-2 OC cells. VICKZ2 was the most frequently expressed family member in serous carcinomas. VICKZ levels measured by pan-VICKZ antibody were significantly higher in primary carcinomas and solid metastases compared to effusions (P < .001). In contrast, VICKZ1 and VICKZ2 were overexpressed in effusions compared to primary carcinomas and solid metastases (P = .016 and P = .024, respectively), and higher VICKZ2 expression in effusions was associated with shorter overall survival in univariate analysis (P = .01). All 3 proteins were localized to OC cells by immunohistochemistry, with tumor-specific expression observed for VICKZ1 and VICKZ2. VICKZ silencing in ES-2 cells led to reduced matrix metalloproteinase 9 activity and reduced invasion. In conclusion, VICKZ2 is the most frequently expressed VICKZ family member in serous OCs. VICKZ1 and VICKZ2 are overexpressed in effusions compared to primary carcinomas and solid metastases, suggesting a biological role at this anatomical site, and appear to have a role in proteolysis and invasion. VICKZ2 may be a prognostic marker in ovarian serous carcinoma effusions.