Metabonomic Study of Lung Cancer and the Effects of Radiotherapy on Lung Cancer Patients: Analysis of Highly Polar Metabolites by Ultraperformance HILIC Coupled with Q-TOF MS

In this study, plasma samples were collected from 28 health volunteers and 66 lung cancer patients. Ultraperformance HILIC/Q-TOF MS-based metabonomic techniques were employed to compare the highly polar metabolites (HPMs) in the plasma of patients with lung cancer and those in the plasma of healthy volunteers. High separation efficiency and good repeatability of the HILIC/Q-TOF MS method were observed. Partial least squares discriminant analysis (PLS-DA) of the data from both ESI+ and ESI- mode revealed good classifications between the health volunteer and the lung cancer patients. This result showed that the HPMs from lung cancer patients and healthy controls were significantly different. The correct classification rate of models in both ion modes reached 100%, indicating that the metabonomics method established in this study could predict the plasma samples with high accuracy. Besides, we found 19 ions that show a significant difference in levels between lung cancer patients and healthy controls. Finally, we conducted a primary study of the effect of radiotherapy on HPMs in lung cancer patients. Clear differences among the HPMs of patients in different radiotherapy periods and significant changes in levels of the 19 ions after radiotherapy were noted. This demonstrated that radiotherapy influences the metabolism system of patients.