Differentially expressed proteins in A549 cells following treatment with nano-SiO2 particles.

Cultures of A549 cells (n = 5) were treated for 4 h with 100 µg/ml or vehicle only (n = 5) in medium containing 1.25% serum. Total cell homogenates were prepared, separated by SDS-PAGE, proteins extracted, digested with trypsin and analysed by LC-MS/MS. Relative amounts of each protein were determined from the ion intensity of the component peptides using Progenesis software and those that varied significantly are indicated by probability and fold difference (treated/untreated, except those shown as minus values which represent fold decreases, i.e. untreated/treated). The identity of the component peptides are shown along with their charge and XCorr score.