A toxicoproteomic study on cardioprotective effects of pre-administration of docetaxel in a mouse model of adriamycin-induced cardiotoxicity.

Studies suggest that pre-administration of docetaxel (DOC) in adriamycin (ADR)-DOC combination anticancer therapy results in stronger antitumor effects and fewer ADR-induced cardiotoxic deaths in mouse model, yet no mechanism explaining this effect has been established. The aim of this study was to identify cellular processes in mouse heart tissue affected by different ADR/DOC dosing protocols using a toxicoproteomic approach. We applied fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) - which consists of fluorogenic derivatization, separation and fluorescence detection by LC, and identification by LC-tandem mass spectrometry - to the proteomic analysis of heart tissue from control, intermittent-dosing (DOC-ADR), and simultaneous-dosing (ADR&DOC) groups. In DOC-ADR group, ADR was administered 12h after DOC injection; in ADR&DOC group, both drugs were administered simultaneously; in control group, saline was administered at the same timing as ADR injection of other groups. Heart samples were isolated from all mice 1 week after the treatment. The highly reproducible and sensitive method (FD-LC-MS/MS) identified nine proteins that were differentially expressed in heart tissue of control and the two treatment groups; seven of these nine proteins participate in cellular energy production pathways, including glycolysis, the tricarboxylic acid cycle, and the mitochondrial electron transport chain. Significantly higher expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was observed in the DOC-ADR group, the group with the fewer cardiotoxic deaths, than in the ADR&DOC group. Therefore, GAPDH may have potential as a drug target for protective intervention and a biomarker for evaluation of the cardioprotective effects in pre-clinical studies.