Effects of the kinase inhibitor sorafenib on heart, muscle, liver and plasma metabolism in vivo using non-targeted metabolomics analysis

Abstract

Background and purpose: The human kinome consists of roughly 500 kinases, including 150 that have been proposed as therapeutic targets. Protein kinases regulate an array of signalling pathways that control metabolism, cell cycle progression, cell death, differentiation and survival. It is not surprising, then, that new kinase inhibitors developed to treat cancer, including sorafenib, also exhibit cardiotoxicity. We hypothesized that sorafenib cardiotoxicity is related to its deleterious effects on specific cardiac metabolic pathways given the critical roles of protein kinases in cardiac metabolism.

Experimental approach: FVB/N mice (10 per group) were challenged with sorafenib or vehicle control daily for 2 weeks. Echocardiographic assessment of the heart identified systolic dysfunction consistent with cardiotoxicity in sorafenib-treated mice compared to vehicle-treated controls. Heart, skeletal muscle, liver and plasma were flash frozen and prepped for non-targeted GC-MS metabolomics analysis.

Key results: Compared to vehicle-treated controls, sorafenib-treated hearts exhibited significant alterations in 11 metabolites, including markedly altered taurine/hypotaurine metabolism (25-fold enrichment), identified by pathway enrichment analysis.

Conclusions and implications: These studies identified alterations in taurine/hypotaurine metabolism in the hearts and skeletal muscles of mice treated with sorafenib. Interventions that rescue or prevent these sorafenib-induced changes, such as taurine supplementation, may be helpful in attenuating sorafenib-induced cardiac injury.

Figure 1

Sorafenib induces cardiac systolic dysfunction in mice after 2 weeks of treatment. Conscious echocardiography showed a fractional shortening of 56 ± 1% at baseline and 50 ± 2% after treatment. n = 5 per group. *P < 0.05.

Figure 2

Analysis of non‐targeted metabolomics of heart from sorafenib‐treated mice compared to vehicle‐treated mice. (A) PLS‐DA of heart metabolites from sorafenib‐treated mice compared to vehicle control mice plotted on two principal components. (B) Heatmap of significant (as assessed by t‐test) metabolites in hearts from sorafenib‐treated mice. (C) Pathway analysis of significant metabolites. (D) Overview of taurine and hypotaurine metabolism and the context of the significant metabolites identified in sorafenib‐treated hearts.

Figure 3

Significant metabolites (as assessed by t‐test) in sorafenib‐treated mouse heart. Nine of the 10 significant metabolites did not have any inputted data points. Stearimide had 1 value imputed (in the sorafenib‐treated group) as detailed in Supporting Information Figure S1. Data represent mean ± SEM. n = 10 per group. *P < 0.05.

Figure 4

Analysis of non‐targeted metabolomics of liver from sorafenib‐treated mice compared to vehicle‐treated mice. (A) PLS‐DA of liver metabolites from sorafenib‐treated mice compared to vehicle control mice plotted on two principal components. (B) Heatmap of significant (as assessed by t‐test) metabolites in livers from sorafenib‐treated mice. (C) Pathway analysis of significant metabolites. (D) Overview of phenylalanine, tyrosine and tryptophan biosynthesis, synthesis/degradation of ketone bodies and butanoate metabolism and the context of the significant metabolites identified in sorafenib‐treated livers.

Figure 5

Significant (as assessed by t‐test) metabolites in sorafenib‐treated mouse liver. Nine of the 14 significant metabolites had any imputed data points. As detailed in Supporting Information Figure S1, the imputed values (#, group) for the remaining metabolites were as follows: squalene (3, sorafenib), asparagine (1, sorafenib), hydroxyprolines (3, control; 1, sorafenib), proline (1, control) and creatine (2, sorafenib). Data represent mean ± SEM. n = 10 per group. *P < 0.05.

Figure 6

Analysis of non‐targeted metabolomics of skeletal muscle (quadriceps femoris) from sorafenib‐treated mice compared to vehicle‐treated mice. (A) PLS‐DA of skeletal muscle metabolites from sorafenib‐treated mice compared to vehicle control mice plotted on two principal components. (B) Heatmap of significant (as assessed by t‐test) metabolites in skeletal muscles from sorafenib‐treated mice. (C) Pathway analysis of significant metabolites. (D) Overview of taurine and hypotaurine metabolism, cysteine and methionine metabolism and the context of the significant metabolites identified in sorafenib‐treated skeletal muscles.

Figure 7

Significant (as assessed by t‐test) metabolites in sorafenib‐treated mouse skeletal muscle (quadriceps femoris). Two of the 5 significant metabolites did not have any imputed data points. As detailed in Supporting Information Figure S1, the imputed values (#, group) for the remaining metabolites were as follows: hypotaurine (1, control; 2, sorafenib), aminomalonic acid (2, control; 2, sorafenib) and dehydroalanine (1, sorafenib). Data represent mean ± SEM. n = 10 per group. *P < 0.05.

Figure 8

Analysis of non‐targeted metabolomics of plasma from sorafenib‐treated mice compared to vehicle‐treated mice. (A) PLS‐DA of plasma metabolites from sorafenib‐treated mice compared to vehicle control mice plotted on two principal components. (B) Heatmap of significant (as assessed by t‐test) metabolites in plasma from sorafenib‐treated mice. (C) Pathway analysis of significant metabolites. (D) Overview of the citrate cycle, the glyoxylated and dicarboxylate metabolism and the context of the significant metabolites identified in sorafenib‐treated plasma.

Figure 9

Significant (as assessed by t‐test) metabolites in sorafenib‐treated mouse plasma. One of the 4 significant metabolites did not have any imputed data points. As detailed in Supporting Information Figure S1, the imputed values (#, group) for the remaining metabolites were as follows: adenine (1, control; 2, sorafenib), malic acid (1, control; 1, sorafenib) and methionine sulfoxide (3, control; 3, sorafenib). Data represent mean + SEM. n = 10 per group. *P < 0.05.