Circulating Levels of HMGB-1 and NPM/B23 proteins and Clinical Significance in Debut NSCLC patients

Alarmins are endogenous molecules that alert the immune system to circumvent the invading antigens in the host. They are basically sensed by specific cellular receptors, leading to recruitment and activation of dendritic cells to mount innate and adaptive immune responses. However, a dual role of alarmins as mediators in either antitumor immunity or tumor progression has been also reported. Here, we investigated the status of the HMGB-1 alarmin and the alarmin-like NPM/B23 in 162 debut NSCLC patients and 60 age-matched healthy individuals as control. NSCLC patients exhibited lower median values of circulating HMGB-1 compared to control (30.04 versus 37.30 ng/ml, p=0.02), but higher levels of HMGB-1 were positively correlated with tumor size > 2.0 cm (p=0.004) irrespectively of tumor histology. Otherwise, circulating NPM/B23 levels were significantly increased in NSCLC patients respect to control (812 versus 551 pg/ml, p=0.00027). Likewise, patients with tumors > 2 cm exhibited higher levels NPM/B23. Strong association was observed between HMGB-1 and NPM/B23 in serum of NSCLC patients (r=0.679 p=0.0001) compared to healthy individuals who exhibited a weaker correlation (r=0.278 p=0.031). However, the strongest correlation between both alarmins was observed in patients with STAS and tumors ≤ 2 cm (r=0.900 p=0.0001). Co-expression of HMGB-1 and NPM/B23 was also observed in tumor tissues although to a lesser extent. Our data unveil that concomitant circulating HMGB-1 and NPM/B23 could serve as a putative alarmin-based biomarker of NSCLC disease progression.