Receptor for advanced glycation end products (RAGE) soluble form (sRAGE): a new biomarker for lung cancer

Receptor for advanced glycation end products (RAGE) may be involved in the pathogenesis of cancer progression. Pathological effects mediated via RAGE are physiologically inhibited by soluble RAGE (sRAGE). The aim of this study was to identify sRAGE and RAGE expression profile in lung cancer patients. An ELISA method was used to quantify serum sRAGE in 45 individuals. Additionally, surgical specimens of 28 lung cancer patients were also included for RAGE expression by immunohistochemistry. Serum sRAGE was significantly decreased in lung cancer patients compared with controls (vs. healthy donors, P=0.034; vs. pulmonary tuberculosis patients, P=0.010). Lower sRAGE concentration was negative correlated with lymph node involvement (NO vs. N1-2, P=0.028). Down regulation of membranous and cytoplasmic expression for RAGE was also lower in lung cancer tissue than in nearby normal lung tissue. Correlation with serum sRAGE concentration and RAGE expression in lung cancer tissue was existed by CV values. The results indicate that serum sRAGE levels are decreased during lung cancer progression and could reflect decreased RAGE expression in tissue. Serum sRAGE may serve as an effective and convenient diagnostic biomarker for lung cancer.