Actinin-4 expression in ovarian cancer: a novel prognostic indicator independent of clinical stage and histological type

Actinin-4 is an isoform of non-muscular alpha-actinin and actin-bundling protein. By enhancing cell motility, actinin-4 shows different biological properties from another isoform of non-muscular actinin 'actinin-1' and variable clinicopathological implications of actinin-4 have been demonstrated in some human malignancies such as breast cancers, lung cancers, and colorectal cancers. We herein described the clinicopathological and prognostic significance of actinin-4 expression in ovarian cancers. Actinin-4 expression was analyzed immunohistochemically in 265 primary ovarian carcinomas: 116 serous, 71 clear cell, 43 endometrioid, and 35 mucinous adenocarcinomas. With reference to endothelial immunoreactivity, cytoplasmic expression of actinin-4 was classified as either low (including negative) or high. Then, various parameters such as patients' characteristics, histopathological findings including E-cadherin and beta-catenin immunoreactivity, and clinical outcome, were compared between groups showing differences in the intensity or intracellular distribution of actinin-4 immunoreactivity. High expression of actinin-4 was demonstrated in 137 (57%) cases and was associated with serous histology (P=0.0075), high histological grade (P