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 neo-plasms. Its immunohistochemical expression has never been investigated in malignant pleural mesothelioma (MPM). We evaluated SRSF1 immunoexpression and its possible relation to angio-genesis in a selected cohort of 10 fluoro-edenite(FE)-induced MPM cases. Methods: Immuno-histochemical 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 ad-ditional in vitro studies, are required to validate our findings.