Growing Human Hepatocellular Tumors Undergo a Global Metabolic Reprogramming

SIMPLE SUMMARY: Metabolic reprogramming is a hallmark of malignancy. Hepatocellular carcinoma (HCC) cancer cells alterations in metabolism are due to the adaption to hypoxia and hypo-nutrient conditions. Several proteins and metabolites associated with glycolysis, tricarboxylic acid cycle and pyrimidine synthesis were found to be differentially regulated in serum, tumor and peritumoral tissues with increased tumor size, suggesting that microenvironment and tumor cell cooperate to regulate metabolism. In this study, the metabolomic characterization of HCC using paired tumor and adjacent liver tissues indicated tumor size-dependent metabolic reprogramming. Targeting cancer metabolism provides potential diagnostic and prognostic metabolic biomarkers. Our study brings new insight into the potential therapeutic use of metabolic targets and a methodological framework and diagnostic and prognostic metabolic markers that may be used in a clinical setting. The stratification of future clinical trials based on these metabolic subsets should improve the development of effective therapies and more intensive surveillance. ABSTRACT: Hepatocellular carcinoma (HCC) is a common malignancy with poor prognosis, high morbidity and mortality concerning with lack of effective diagnosis and high postoperative recurrence. Similar with other cancers, HCC cancer cells have to alter their metabolism to adapt to the changing requirements imposed by the environment of the growing tumor. In less vascularized regions of tumor, cancer cells experience hypoxia and nutrient starvation. Here, we show that HCC undergoes a global metabolic reprogramming during tumor growth. A combined proteomics and metabolomics analysis of paired peritumoral and tumor tissues from 200 HCC patients revealed liver-specific metabolic reprogramming and metabolic alterations with increasing tumor sizes. Several proteins and metabolites associated with glycolysis, the tricarboxylic acid cycle and pyrimidine synthesis were found to be differentially regulated in serum, tumor and peritumoral tissue with increased tumor sizes. Several prognostic metabolite biomarkers involved in HCC metabolic reprogramming were identified and integrated with clinical and pathological data. We built and validated this combined model to discriminate against patients with different recurrence risks. An integrated and comprehensive metabolomic analysis of HCC is provided by our present work. Metabolomic alterations associated with the advanced stage of the disease and poor clinical outcomes, were revealed. Targeting cancer metabolism may deliver effective therapies for HCC.