Shared and unique metabolic features of the malignant and benign thyroid lesions determined with use of 1H HR MAS NMR spectroscopy

Abstract

The purpose of this work was to investigate the distinct and common metabolic features of the malignant and benign thyroid lesions in reference to the non-transformed tissue from the contralateral gland (chronic thyroiditis and colloid goiter). ¹H HR MAS NMR spectra of 38 malignant lesions, 32 benign lesions and 112 samples from the non-tumoral tissue (32 from chronic thyroiditis and 80 samples from colloid goiter) were subjected both to multivariate and univariate analysis. The increased succinate, glutamine, glutathione, serine/cysteine, ascorbate, lactate, taurine, threonine, glycine, phosphocholine/glycerophosphocholine and decreased lipids were found in both lesion types in comparison to either colloid goiter or chronic thyroiditis. The elevated glutamate and choline, and reduced citrate and glucose were additionally evident in these lesions in reference to goiter, while the increased myo-inositol-in comparison to thyroiditis. The malignant lesions were characterized by the higher alanine and lysine levels than colloid goiter and thyroiditis, while scyllo-inositol was uniquely increased in the benign lesions (not in cancer) in comparison to both non-tumoral tissue types. Moreover, the benign lesions presented with the unique increase of choline in reference to thyroiditis (not observed in the cancerous tissue). The metabolic heterogeneity of the non-tumoral tissue should be considered in the analysis of metabolic reprogramming in the thyroid lesions.

Figure 1

The scheme presenting the constructed multivariate models.

Figure 2

Representative HR MAS ¹H NMR CPMG spectra of the malignant lesions, benign lesions, chronic thyroiditis (non-tumoral tissue) and colloid goiter (non-tumoral tissue). The assigned signals: 1—fatty acids (FA) 0.9 ppm, 2—fatty acids (FA) 1.3 ppm, 3—fatty acids (FA) 1.59 ppm, 4—fatty acids (FA) 2.03 ppm, 5—fatty acids (FA) 2.25 ppm, 6—fatty acids (FA) 2.77 ppm, 7—citrate (Cit), 8—isoleucine (Ile), 9—leucine (Leu), 10—valine (Val), 11—lactate (Lac), 12—alanine (Ala), 13—lysine (Lys), 14—acetate (Ace), 15—glutamate (Glu), 16—succinate (Suc), 17—glutamine (Gln), 18—glutathione (GSH), 19—creatine (Cre), 20—choline (Cho), 21—phosphocholine (Pho), 22—glycerophosphocholine (GPC), 23—scyllo-inositol (SI), 24—taurine (Tau), 25—myo-inositol (MI), 26—glycine (Gly), 27—serine (Ser), 28—cysteine (Cys), 29—threonine (Thre), 30—ascorbate (Asc), 31—glucose (Glc), 32—aspartate (Asp). The image was created using Statistica 12.5 software (StatSoft, Tulsa, USA). www.statsoft.pl.

Figure 3

The scores plot obtained from the PCA analysis of the whole dataset (model 1): blue filled circle the benign lesions (BL), red filled circle the malignant lesions (ML), green filled circle colloid goiter (CG, the non-tumoral tissue) and black filled circle chronic thyroiditis (CT, the non-tumoral tissue). The image was created using SIMCA-P 15.0 software package (Umetrics AB, Umeå, Sweden). https://www.sartorius.com.

Figure 4

The OPLS-DA models: (a) the scores and (b) loadings plots obtained from the model 2, (c) the scores and (d) loadings plots obtained from the model 3, (e) the scores and (f) loadings plots obtained from the model 4. The signals on the loadings plots are colored according to the pcorr(1) values. The image was created using SIMCA-P 15.0 software package (Umetrics AB, Umeå, Sweden). https://www.sartorius.com.

Figure 5

The O-PLS-DA scores plots for the models: (a) 7, (b) 8, (c) 9, (d) 10. Red filled circle the malignant lesions (ML), blue filled circle the benign lesions (BL), green filled circle colloid goiter (CG), and black filled circle chronic thyroiditis (CT). The image was created using SIMCA-P 15.0 software package (Umetrics AB, Umeå, Sweden). https://www.sartorius.com.

Figure 6

A Shared and Unique Structures (SUS) analysis – a SUS-plot comparing the OPLS-DA models: (a) 7 vs 9 and (b) 8 vs 10. pink filled square—section 1, |pcorr(1)| > 0.45 in both models, blue filled square—section 2, |pcorr(1)| > 0.45 in one model and 0 < |pcorr(1)| < 0.3 in the other model and yellow filled square—section 3, |pcorr(1)| values > 0.45 in one model and 0.3 < |pcorr(1)| < 0.45 in the other model. Red open square denotes the area where the metabolites do not contribute to the models. The dashed red lines mark the limits of the sections. The metabolites located along the diagonals represent the shared features while the off-diagonal metabolites represent the unique features. The image was created using SIMCA-P 15.0 software package (Umetrics AB, Umeå, Sweden). https://www.sartorius.com.

Figure 7

Metabolome views obtained from the pathways analysis presenting the pathways altered in (a) the malignant lesions vs. colloid goiter, (b) the benign lesions vs. colloid goiter, (c) the malignant lesions vs. chronic thyroiditis and (d) the benign lesions vs. chronic thyroiditis. On the y-axis, the –log (p) value represents the quantitative perturbation of pathways. On the x-axis, the pathway impact value (the score is from 0 to 1) refers to the centrality of a metabolite in the metabolic network. The node color, varying from yellow to red, is based on its p value, and the node radius is determined on the basis of their pathway impact values. Only pathways with p < 0.05 and/or pathway impact value > 0.10 are considered. The image was created using Metaboanalyst 4.0 software. https://www.metaboanalyst.ca.