Prognostic significance of S100A16 subcellular localization in lung adenocarcinoma

To discover novel tumor markers for lung adenocarcinoma (AC), we performed proteomics analysis and reported a correlation between S100A16 membranous expression in AC tissues and a poor prognosis. However, some patients with a good prognosis also showed S100A16 membranous staining. We re-evaluated immunohistochemically stained tissues, and found membrane-positive and nucleus-negative expressions to be significantly higher in the presence of the following: male, smoker, positive nodal metastasis, higher p-TNM stage, larger tumor, poorer differentiation, positive for lymphatic invasion, positive for vascular invasion, and positive for pleural invasion (all factors P < .05). This pattern of staining was also an independent prognostic factor. Furthermore, we analyzed S100A16 mRNA expression using TCGA and Kaplan-Meier plotter databases, and found that higher S100A16 mRNA expression in AC was significantly correlated with poorer survival. To our knowledge, there has been no comprehensive study focused on both S100A16 protein and mRNA expression levels in AC patients. Our results suggest that the subcellular localization of S100A16 and S100A16 mRNA expression levels is a promising prognostic marker for AC.