Proteomic Analysis of Radiation-Induced Acute Liver Damage in a Rabbit Model

Radiation-induced liver damage (RILD) has become a limitation in radiotherapy for hepatocellular carcinoma. We established a rabbit model of RILD by CyberKnife. Electron microscopy analysis revealed obvious nuclear atrophy and disposition of fat in the nucleus after irradiation. We then utilized a mass spectrometry-based label-free relative quantitative proteomics approach to compare global proteomic changes of rabbit liver in response to radiation. In total, 2365 proteins were identified, including 338 proteins that were significantly dysregulated between irradiated and nonirradiated liver tissues. These differentially expressed proteins included USP47, POLR2A, CSTB, MCFD2, and CSNK2A1. Real-time polymerase chain reaction confirmed that USP47 and CABLES1 transcripts were significantly higher in irradiated liver tissues, whereas MCFD2 and CSNK2A1 expressions were significantly reduced. In Clusters of Orthologous Groups of proteins analysis, differentially expressed proteins were annotated and divided into 24 categories, including posttranslational modification, protein turnover, and chaperones. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the enriched pathways in dysregulated proteins included the vascular endothelial growth factors (VEGF) signaling pathway, the mitogen-activated protein kinase (MAPK) signaling pathway, and the adipocytokine signaling pathway. The identification of proteins and pathways is crucial toward elucidating the radiation response process of the liver, which may facilitate the discovery of novel therapeutic targets.