Immunohistochemical Expression of Aquaporin-1 in Fluoro-Edenite-Induced Malignant Mesothelioma: A Preliminary Report

International Journal of Molecular Sciences 2018 February [Link]

Angelico G, Caltabiano R, Loreto C, Ieni A, Tuccari G, Ledda C, Rapisarda V

Abstract

BACKGROUND:
The immunohistochemical expression of aquaporin-1 (AQP1) in asbestos-related malignant pleural mesothelioma (MPM) is emerging as a useful prognostic indicator of improved survival. A significantly increased incidence of MPM in a small town in southern Italy was ascribed to exposure to fluoro-edenite (FE), a naturally occurring asbestos fiber. We investigated the immunohistochemical expression of AQP1 in patients affected by FE-related MPM; taking into consideration its suggested independent prognostic role, its possible correlation with clinicopathological parameters and patient outcome was also evaluated.

METHODS:
Ten patients were selected for this study, as neoplastic tissue blocks, clinical and follow-up data were available. The immunohistochemical overexpression of AQP1 was defined as ≥50% of tumor cells showing membranous staining.

RESULTS:
Six cases showed AQP1 expression in ≥50% of tumor cells; in this group, a significant association of AQP1 overexpression with an increased median overall survival (OS) of 26.3 months was observed. By contrast, four patients exhibited an AQP1 score of <50% of stained cells, with a shorter median OS of 8.9 months. CONCLUSIONS: The present study represents further confirmation of the hypothesized prognostic role of AQP1, which seems a reliable prognostic indicator.