Journal des biomarqueurs moléculaires et du diagnostic

Loss of ANXA7 Expression is Associated with Poor Patient Survival in Ovarian Cancer

Abstract

Meera Srivastava, Ofer Eidelman, Lukas Bubendorf and Harvey B. Pollard

Epithelial ovarian cancer is morphologically heterogeneous being classified as serous, endometrioid, clear cell, or mucinous. Molecular genetic analysis has suggested a role for tumor suppressor genes located at chromosome 10q in epithelial ovarian cancer pathogenesis. Our objective is to evaluate the expression of ANXA7, a novel tumor suppressor gene located on 10q21, in these epithelial ovarian cancer subtypes, and to investigate its correlation with patient survival. ANXA7 is ubiquitously expressed in small amounts in nearly every normal cell and the Anxa7 (+/-) knockout mouse has a cancer prone phenotype. Altered ANXA7 protein levels are associated with prognostically challenging aggressive forms of prostate and breast cancer. So far, information is not available regarding the association of ANXA7 expression in ovarian cancer and patient survival. Therefore, we used human tumor tissue microarray (TMA) technology in order to evaluate the ANXA7 immunoreactivity as possible diagnostic and/or prognostic marker of ovarian cancer by immunoperoxidase assay using ANXA7 monoclonal antibody. Using a 129 case diagnostic human tumor tissue microarray, we report that the expression of ANXA7 is significantly reduced and is associated with disease progression. Furthermore, using a separate 301 case retrospective prognostic tumor tissue microarray, we find that loss of ANXA7 expression is also significantly associated with poor over-all patient survival. We conclude that ANXA7 may be a new prognostic marker or a target for improving the treatment efficiency of patients with ovarian cancers.