Quantitative Proteomic Analysis of Cultured Human Fibroblast Cells Following Co-exposure to Cadmium and 4-(Methylnitrosamino)-1-(3-pyridinyl)-1-butanone

摘要

Cadmium and the tobacco specific N-nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridinyl)-1-butanone (NNK), are two well known carcinogens found in tobacco and its smoke. To date, the interactive effects for heavy metals and TSNA combinations at the protein level in biological systems remain largely unexplored. In this study, we utilized stable isotope labeling by amino acids in cell culture together with mass spectrometry, to assess the perturbation of protein expression following Cd and NNK exposure in human skin fibroblast (GM00637) cells. With this approach, we were able to identify 3294 proteins and quantification of 2968 proteins in the GM00637 cell line. Our results indicated that Cd and NNK exposure significantly altered the expression of 349 and 176 proteins, respectively. Additionally, the expression for 319 proteins, were found to be significantly altered following Cd/NNK co-exposure. Our results showed that some unique cellular pathways were disrupted by the different treatment groups. Co-exposure to the Cd and NNK led to, among the perturbation of other cellular pathways, the upregulation of DNA double-strand break repair pathway. Increased DNA damage resulting from co-exposure to Cd and NNK was further confirmed by measuring the expression of gamma-H2Ax via western blot analysis.