Immunohistochemical Expression of Serine and Arginine-Rich Splicing Factor 1 (SRSF1) in Fluoro-Edenite-Induced Malignant Mesothelioma: A Preliminary Study

The Serine and Arginine-Rich Splicing Factor 1 (SRSF1) has a proto-oncogenic function, being associated with angiogenesis and frequently overexpressed in many human malignant neoplasms. Its immunohistochemical expression has never been investigated in malignant pleural mesothelioma (MPM). We evaluated SRSF1 immunoexpression and its possible relation to angiogenesis in a selected cohort of 10 fluoro-edenite(FE)-induced MPM cases. Methods: Immunohistochemical analyses with an anti-SRSF1 antibody were performed. We interpreted the cases as positive if tumor cell nuclei were stained; a semi-quantitative analysis of the cases was performed by evaluating the intensity of staining and the percentage of tumor positive cells. A microvessel density (MVD) count was also performed. Results: High and low immunoexpressions of SRSF1 were seen in six and four MPMs, respectively. A trend of shorter overall survival was found in FE-induced MPM patients with SRSF1 overexpression. In addition, a significant association between high-MVD and high SRSF1 immunoexpression (p = 0.0476) was found. Conclusions: SRSF1 appears to be involved in MPM pathogenesis and its immunoexpression may represent a prognostic biomarker capable of identifying subgroups of patients with different prognosis. However, given the preliminary nature of the present study, further investigations on larger series, and additional in vitro studies, are required to validate our findings.