The inter-individual variability outperforms the intra-individual variability of differentially expressed proteins prior and post irradiation in lymphoblastoid cell lines

Context: Radio-sensitivity in normal tissue is characterized by heterogeneity throughout the population and the absence of pre-diagnostic biomarkers. Objective: We conducted a proteomic approach to search for radiation characteristic protein regulation. Materials and methods: Cell lines were 10 Gy irradiated and analysed by 2D-DIGE after 24 h. Results were analysed intra-and inter-individually. The principal component analysis and hierarchical clustering was applied to all datasets. Results: Differences in intra-individual spot abundance prior and post irradiation exactly show the separation of sample classes in two groups: sham-irradiated and irradiated. The inter-individual datasets clustered according to the cell line. The intra-individual differences on protein level after gamma-irradiation are very low, compared with the inter-individual differences among cell lines derived from the same tissue. Conclusion: The application of 2-D DIGE may offer a realistic chance for a better molecular characterization of radio-sensitivity and for the discovery of candidate biomarkers.