Metabolomics of head and neck cancer in biofluids: an integrative systematic review.

INTRODUCTION: Head and neck cancer (HNC) is the fifth most common cancer globally. Diagnosis at early stages are critical to reduce mortality and improve functional and esthetic outcomes associated with HNC. Metabolomics is a promising approach for discovery of biomarkers and metabolic pathways for risk assessment and early detection of HNC. OBJECTIVES: To summarize and consolidate the available evidence on metabolomics and HNC in plasma/serum, saliva, and urine. METHODS: A systematic search of experimental research was executed using PubMed and Web of Science. Available data on areas under the curve was extracted. Metabolic pathway enrichment analysis were performed to identify metabolic pathways altered in HNC. Fifty-four studies were eligible for data extraction (33 performed in plasma/serum, 15 in saliva and 6 in urine). RESULTS: Metabolites with high discriminatory performance for detection of HNC included single metabolites and combination panels of several lysoPCs, pyroglutamate, glutamic acid, glucose, tartronic acid, arachidonic acid, norvaline, linoleic acid, propionate, acetone, acetate, choline, glutamate and others. The glucose-alanine cycle and the urea cycle were the most altered pathways in HNC, among other pathways (i.e. gluconeogenesis, glycine and serine metabolism, alanine metabolism, etc.). Specific metabolites that can potentially serve as complementary less- or non-invasive biomarkers, as well as metabolic pathways integrating the data from the available studies, are presented. CONCLUSION: The present work highlights utility of metabolite-based biomarkers for risk assessment, early detection, and prognostication of HNC, as well as facilitates incorporation of available metabolomics studies into multi-omics data integration and big data analytics for personalized health.

Predictive Gestational Diabetes Biomarkers With Sustained Alterations Throughout Pregnancy.

Gestational diabetes mellitus (GDM) results in an increased risk of pre- and postpartum health complications for both mother and child. Metabolomics analysis can potentially identify predictive biomarkers and provide insight into metabolic alterations associated with GDM pathogenesis and progression, but few metabolomics studies investigate alterations observed across the first and third trimester. We hypothesize that metabolites altered in first-trimester GDM that remain altered in late pregnancy may best inform interventions. Metabolomic studies comparing plasma and serum metabolite alterations in GDM vs non-GDM pregnancies were retrieved by searching PubMed, Medline, and CINAHL Plus databases. The present scoping review summarizes the metabolites found to be consistently altered throughout the course of GDM and proposes mechanisms that explain how these metabolic perturbations relate to GDM development and progression. Metabolites involved in fatty acid metabolism, reductive carboxylation, branched-chain amino acid metabolism, cell membrane lipid metabolism, purine degradation, and the gut microbiome were found to be altered throughout GDM pregnancies, with many of these pathways showing mechanistic links to insulin resistance, inflammation, and impaired cell signaling. Future studies are required to investigate if normalization of these perturbed pathways can be the targets of interventions.