Cell metabolomics analyses revealed a role of altered fatty acid oxidation in neurotoxicity pattern difference between nab-paclitaxel and solvent-based paclitaxel

Abstract

Peripheral neuropathy (PN) is a dose-limiting, painful adverse reaction associated with the use of paclitaxel. This common side effect was often partially attributed to the solvent used for solubilization of the highly hydrophobic drug substance. Therefore, the development of alternative formulations thrived, which included that of Abraxane® containing nanoparticle albumin-bound paclitaxel (nab-paclitaxel). However, studies demonstrated inconsistent conclusions regarding the mitigation of PN in comparison with the traditional formulation. The mass spectrometry-based cell metabolomics approach was used in the present study to explore the potentially associated mechanisms. Although no significant difference in the effects on cell viability was observed, fold changes in carnitine, several acylcarnitines and long-chain fatty acid(s) were significantly different between treatment groups in differentiated and undifferentiated SH-SY5Y cells. The most prominent difference observed was the significant increase of octanoylcarnitine in cells treated with solvent-based paclitaxel, which was found to be associated with significant decrease of medium-chain acyl-CoA dehydrogenase (MCAD). The findings suggested the potential role of altered fatty acid oxidation in the different neurotoxicity patterns observed, which may be a possible target for therapeutic interventions worth further investigation.

Fig 1

Cell viability of undifferentiated (A) and differentiated (B) SH-SY5Y cells treated with 100 nM of paclitaxel, Phyxol, or Abraxane^® for 24 hours assessed by the sulforhodamine B (SRB) assay. Data are expressed as mean ± standard deviation of three independent experiments.

Fig 2

Fold changes relative to the control group in the levels of carnitine and acylcarnitines of undifferentiated (A) and differentiated (B) SH-SY5Y cells treated with 100 nM of paclitaxel (in dimethyl sulfoxide), Phyxol, or Abraxane^® for 24 hours. Three independent samples were prepared for each condition in each experiment. Each sample was analyzed twice by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry. Three independent experiments were conducted. Calibration curves of the standards and the internal standards for carnitine and acetylcarnitine were used for quantitation of these two metabolites. Data are presented as mean ± standard deviation. One-way analysis of variance was used to analyze the difference in fold changes between treatment groups for each metabolite. If the difference was significant, all pairs, Tukey HSD (honestly significant difference) post-hoc test comparisons were performed. *, p < 0.05; **, p < 0.01; ***, p < 0.001.

Fig 3

Fold changes relative to the control group in the levels of long-chain and very long-chain fatty acids of undifferentiated (A) and differentiated (B) SH-SY5Y cells treated with 100 nM of paclitaxel (in dimethyl sulfoxide), Phyxol, or Abraxane^® for 24 hours. Three independent samples were prepared for each condition in each experiment. Each sample was analyzed twice by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Three independent experiments were conducted. Data are presented as mean ± standard deviation. One-way analysis of variance was used to analyze the difference in fold changes between treatment groups for each metabolite. If the difference was significant, all pairs, Tukey HSD (honestly significant difference) post-hoc test comparisons were performed. *, p < 0.05; **, p < 0.01; ***, p < 0.001.

Fig 4

Expression of medium-chain acyl-CoA dehydrogenase (MCAD) proteins in undifferentiated (A) and differentiated (B) SH-SY5Y cells treated with 100 nM of paclitaxel (in dimethyl sulfoxide), Phyxol, or Abraxane^® for 24 hours. Upper panels show the representative Western blot images, while lower panels demonstrate the fold change relative to the control group, which are presented as mean ± standard deviation. Six independent samples were prepared for each condition. One-way analysis of variance was used to analyze the difference in fold changes; all pairs, Tukey HSD (honestly significant difference) post-hoc test comparisons were then performed. **, p < 0.01; ***, p < 0.001.