A crucial and distinctive feature of tuberculosis infection is that Mycobacterium tuberculosis (Mtb) resides in granulomatous lesion at various stages of disease development and necrosis, an aspect that is little understood. We used a novel approach, applying high resolution magic angle spinning nuclear magnetic resonance spectroscopy (HRMAS NMR) directly to infected tissues, allowing us to study the development of tuberculosis granulomas in guinea pigs in an untargeted manner. Significant up-regulation of lactate, alanine, acetate, glutamate, oxidized and the reduced form of glutathione, aspartate, creatine, phosphocholine, glycerophosphocholine, betaine, trimethylamine N-oxide, myo-inositol, scyllo-inositol, and dihydroxyacetone was clearly visualized and was identified as the infection progressed. Concomitantly, phosphatidylcholine was down-regulated. Principal component analysis of NMR data revealed clear group separation between infected and uninfected tissues. These metabolites are suggestive of utilization of alternate energy sources by the infiltrating cells that generate much of the metabolites in the increasingly necrotic and hypoxic developing granuloma through the glycolytic, pentose phosphate, and tricarboxylic acid pathways. The most relevant changes seen are, surprisingly, very similar to metabolic changes seen in cancer during tumor development.

High-resolution magic-angle spinning (HR-MAS) proton NMR spectroscopy is used to explore the metabolic signatures of head and neck squamous cell carcinoma (HNSCC) which included matched normal adjacent tissue (NAT) and tumor originating from tongue, lip, larynx and oral cavity, and associated lymph-node metastatic (LN-Met) tissues. A total of 43 tissues (18 NAT, 18 Tumor and 7 LN-Met) from twenty-two HNSCC patients were analyzed. Principal Component Analysis of NMR data showed a clear classification between NAT and tumor tissues, however, LN-Met tissues were classified among tumor. A partial least squares discriminant analysis model generated from NMR metabolic profiles was used to differentiate normal from tumor samples (Q2 > 0.80, Receiver Operator Characteristic area under the curve > 0. 86, using 7-fold cross validation). HNSCC and LN-Met tissues showed elevated levels of lactate, amino acids including leucine, isoleucine, valine, alanine, glutamine, glutamate, aspartate, glycine, phenylalanine and tyrosine, choline containing compounds, creatine, taurine, glutathione and decreased levels of triglycerides. These elevated metabolites were associated with highly active glycolysis, increased amino acids influx (anaplerosis) into the TCA cycle, altered energy metabolism, membrane choline phospholipid metabolism, and oxidative and osmotic defense mechanisms. Moreover, decreased levels of triglycerides may indicate lipolysis followed by β-oxidation of fatty acids that may exist to deliver bioenergy for rapid tumor cell proliferation and growth.