Published online Jul 14, 2014. doi: 10.3748/wjg.v20.i26.8653
Revised: March 17, 2014
Accepted: April 27, 2014
Published online: July 14, 2014
Processing time: 168 Days and 15.4 Hours
AIM: To perform plasma free amino acid (PFAA) profiling of esophageal squamous cell carcinoma (ESCC) patients at different pathological stages and healthy subjects.
METHODS: Plasma samples from ESCC patients (n = 51) and healthy control adults (n = 60) were analyzed by high-performance liquid chromatography (HPLC). The ESCC patients included moderate/poorly-differentiation (n = 24), lymph node metastasis (n = 17) and clinical stage > Ib2 (n = 36). Partial least squares discriminant analysis was performed to demonstrate that the PFAA metabolic patterns enabled discrimination between ESCC patients and controls, and the Student t test was applied to assess significant differences in PFAA concentrations between the two groups.
RESULTS: There were significant differences in the PFAA profiles between controls and ESCC patients. Compared with healthy controls, the levels of Asp, Glu, Gly, His, Thr, Tau, Ala, Met, Ile, Leu, and Phe were decreased in ESCC patients, but Cys was increased. There exists a strong correlation between PFAA profiles and clinicopathological characteristics in ESCC patients. The levels of many PFAAs (i.e., Glu, Asp, Ser, Gly, Tau, Ala, Tyr, Val, Ile, and Leu) were related to pathological grading, lymph node metastasis, and ESCC clinical stage. Very good discrimination between ESCC patients and control subjects was achieved by multivariate modeling of plasma profiles.
CONCLUSION: HPLC-based plasma profiling analysis was shown to be an effective approach to differentiate between ESCC patients and controls. PFAA profiles may have potential value for screening or diagnosing ESCC.
Core tip: Recently, metabolomics-based techniques have been developed to identify cancer-related metabolic signatures for early cancer detection. However, studies on esophageal squamous cell carcinoma (ESCC) remain limited. This study used high-performance liquid chromatography to quantitatively study plasma free amino acid (PFAA) changes in ESCC patient, and analyze the correlation between PFAA profiles and clinicopathological characteristics of ESCC. The results showed that most of the amino acids were differentially expressed in ESCC patients and control subjects, and were related to the ESCC clinicopathological characteristics. The study suggests that PFAA profiling is of potential value for screening or diagnosing ESCC.