Proteome and Phosphoproteome Profiling of Non-Small Cell Lung Cancer Cell Line A549 Treated with TRAIL.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is recognized for its promising therapeutic effects against cancer. However, mechanisms underlying the effect of TRAIL on protein expression, signal transduction, and apoptosis induction remain unclear. We surmised that a systematic analysis of the proteome and phosphoproteome associated with TRAIL signaling may help elucidate the mechanisms involved and facilitate the development of therapeutics. Therefore, we investigated the proteome and phosphoproteome of non-small cell lung cancer cell line A549 treated with TRAIL. Our results indicated that 126 proteins and 1684 phosphosites were markedly differentially expressed between the phosphate-buffered saline- and TRAIL-treated groups. The expression at protein and phosphosite levels were not completely consistent. Gene ontology functional analysis revealed that metal ion (zinc) binding was highly affected by TRAIL treatment. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that almost all pathways that involved differentially expressed phosphosites were associated with apoptosis. We also identified an important kinase, AKT1, and its series of substrates in TRAIL signaling. The results of this study may provide guidance for future research on tumor therapy using TRAIL.