Abstract
BACKGROUND AND OBJECTIVE: proper tumor markers are useful to diagnosis, prognosis and treatment for lung cancer. The aim of this study is to examine the levels of alpha-enolase (ENO1) protein in the tumor tissues and peripheral plasma samples obtained from non-small cell lung cancer (NSCLC) patients, and evaluate its potential clinical significance. METHODS: the ENO1 protein levels in the tumor tissues and corresponding normal tissues from 16 cases of lung squamous cell carcinoma were analyzed by Western blot. The ENO1 protein levels in the plasma samples from 42 healthy individuals, 34 patients with lung benign disease and 84 patients with NSCLC were measured by double antibody sandwich enzyme-linked immunosorbent assay. RESULTS: for 87.5% (14/16) of the patients with lung squamous cell carcinoma, the ENO1 protein level in the tumor tissues was higher than that in the corresponding normal lung tissues. The ENO1 protein level in the plasma of NSCLC patients was significantly higher than that in the plasma of healthy individuals (P=0.031) and patients with lung benign disease (P=0.019). Furthermore, the ENO1 protein level was significantly higher in the plasma of patients with lung adenocarcinoma than that of patients with lung squamous cell carcinoma. CONCLUSIONS: the elevated levels of ENO1 protein in the tumor tissues and the plasma samples from NSCLC patients indicate ENO1 may be a candidate biomarker of lung cancer.