Background & objective: Some molecular changes occurred in esophageal precancerous and cancerous lesions could be reflected in the serum, but the clinical application is limited because of their low sensitivity and specificity. Serum proteomic profiling is much desirable in identifying the proteins closely related to esophageal carcinogenesis. This study was to characterize the serum protein profiles of the subjects with normal esophagus, esophageal precancerous and cancerous lesions from Linzhou, the area with the highest incidence of esophageal carcinoma (EC) in Henan Province, Northern China.
Methods: Proteomic spectra were generated with surface-enhanced laser desorption/inionation-time of flight-mass spectra (SELDI-TOF-MS) and weak cation exchange (WCX2) protein chip system, and analyzed by bioinformatics like decision tree classification algorithm on a set of serum from 130 symptom-free subjects [including 63 cases with normal esophageal epithelia, 40 with basal cell hyperplasia (BCH), and 27 with dysplasia (DYS)] and 30 EC patients from Linzhou.
Results: One protein in BCH group with a ratio of mass to charge (M/Z) of M9 306.61 u, 1 in DYS group with a M/Z ratio of M13 765.9 u, and 2 in EC group with M/Z ratios of M2 942.15 u and M15 953.4 u were selected to build 3 decision tree classification models to identify the subjects with BCH, DYS, and EC, respectively. With these classification models, the sensitivities of identifying BCH, DYS and EC were 57.5% (23/40), 88.8% (24/27) and 96.6% (29/30), respectively, in the training sets, and 57.5% (23/40), 66.6% (18/27) and 60.0% (18/30), respectively, in the test sets; the specificities of identifying BCH, DYS and EC were 96.8% (61/63), 63.4% (40/63) and 92.0% (58/63), respectively, in the training sets, and 95.2% (60/63), 71.4% (45/63) and 84.1% (53/63), respectively, in the test sets.
Conclusion: The protein sets with M/Z ratios of M9 306.61 u, M13 765.9 u, M2 942.15 u, and M15 953.4 u may contain promising serum biomarkers for screening the subjects with high-risk of EC.