| Paired samples of cancer and adjacent normal sections of colon tissue from colon adenocarcinoma patients were extracted by a methanol-chloroform-water mixture, partitioned into aqueous and organic phases, and subsequently examined by 1H NMR. Spectra were binned, normalized, and analyzed for significant statistical differences between normal and cancer groups. Principal component analysis and partial least squares discriminant analysis distinguished normal spectra from cancer with few false classifications for aqueous extractions, but were less successful in discriminating between normal and tumor tissues when applied to data acquired from organic extractions. Studies of organic spectra indicated that cholesterol, cholesterol esters, and phospholipids were elevated in cancer samples while triacylglycerol levels were depressed. Poly-unsaturated lipids also appeared predominantly in tumor biopsies, whereas mono-unsaturated lipids were more common in normal colon tissue. Analysis of aqueous samples showed increased quantities of uridine diphosphate N-acetyl-D-glucosamine, uracil, proline, lactate, O-phosphoethanolamine, glutamate, aspartate, oxidized glutathione, inosine monophosphate, and taurine in cancer spectra. In contrast, the metabolites glucose, myo-inositol, creatine, and scyllo-inositol were more prominent in normal spectra. The significant differences observed reflect normal and tumor cell metabolism in colon adenocarcinoma. |
