High-mobility group nucleosome-binding protein 1 is a novel clinical biomarker in non-small cell lung cancer

The involvement of alarmin high-mobility group nucleosome-binding protein 1 (HMGN1) in non-small cell lung cancer (NSCLC) is unknown. To address the presence of HMGN1 in the serum of different stages of NSCLC patients and healthy controls, we enrolled a consecutive sample of adult serum at diagnosis and correlated it with clinicopathologic outcomes. A total of 100 NSCLC patients and 23 healthy volunteers were enrolled from January 2012 through December 2013. Serum HMGN1 levels were determined by enzyme-linked immunosorbent assay (ELISA). Additionally, HMGN1 levels in 50 NSCLC patients with early-stage disease who received curative pneumonectomy were correlated with survivals. Kaplan-Meier plots were used to analyze the data. The patients with NSCLC were characterized by significantly higher serum levels of HMGN1 (0.4585 +/- 0.0640 ng/ml) compared to those in healthy controls (0.3578 +/- 0.0304 ng/ml). The serum HMGN1 levels were 0.4027 +/- 0.0271 ng/ml, 0.4604 +/- 0.0328 ng/ml, 0.5408 +/- 0.0459 ng/ml, and 0.4213 +/- 0.0341 ng/ml in patients with TNM stages I, II, IV, and IV, respectively (p < 0.001). There were significant differences among four groups (p < 0.001). Additionally, a positive correlation between serum HMGN1 and tumor stage was found in local disease, while serum HMGN1 level in metastatic NSCLC patients was significantly decreased. The Kaplan-Meier plots showed that patients with high serum HMGN1 had a poorer overall survival (OS) after curative pneumonectomy than those with low serum HMGN1 (p = 0.019). Inflammation triggered by alarmins plays a role in NSCLC pathogenesis. HMGN1 can serve as a useful clinical parameter for evaluating disease progression and predicting the outcomes for early-stage patients with NSCLC undergoing pneumonectomy.