High resolution-magic angle spinning (HR-MAS) NMR-based metabolomic fingerprinting of early and recurrent hepatocellular carcinoma

In order to elucidate the metabolite changes associated with hepatocellular carcinoma (HCC) oncogenesis and progression, we compared the profiles obtained by 1D proton HRMAS NMR spectroscopy of 51 needle biopsies (14 primary nodules, 14 recurrent, and 23 paired cirrhotic specimens). The diagnosis of HCC was based on 2 concordant imaging techniques and was confirmed by histology in 20 cases. Spectroscopy was performed using a Bruker AVANCE II 600 spectrometer. One-dimensional proton spectra were acquired using water-suppressed (noesygppr) pulse and spin-echo CPMG sequences. Signals were assigned by BBIOREFCODE and were confirmed by HSQC. Statistics was based on the SIMCA P package. Orthogonal projection to latent structure (OPLS-DA) showed a clear separation between tumor and cirrhosis. This difference was maintained when the analysis of paired samples from primary to recurrent nodules was split. OPLS-DA of primary and recurrent nodules also showed a significant difference. The relationship between metabolite profile and HCC volume was evaluated comparing the spectra obtained in tumors ≤2 cm ( n = 15) and in those larger than 2 cm ( n = 11). Univariate comparison of the most relevant metabolites showed that: (1) increased choline, TMAO, and decreased saturated fatty acids differentiate HCC from the surrounding tissue; (2) increased lactate and myo-inositol differentiate recurrent from primary HCC; (3) decreased saturated fatty acids characterize large HCC nodules.