The influence of free radicals from cigarette smoke on MCF-7 cell lines has been investigated in our laboratory using proteomics study. The work presented here will expose the comparison between untreated cells and cells incubated with conventional cigarette smoke solution. In order to highlight the MCF-7 modifications induced by cigarette smoke, 2D DIfferential Gel Electrophoresis (2D-DIGE) is the most appropriate method due to its reproducibility and resolution. Briefly, 2D-DIGE consists in labelling proteins from treated and untreated cells by Cy3 and Cy5 fluorescent reagents. The labeled cells are then mixed and separated on the same gel. The gel analysis is performed using dedicated DeCyder software. The analysis was then performed on a platform designed specifically for use with DIGE, spots were excised using a spot picker, proteins were digested in gel using the trypsin by a spot digester and the peptides were eluted and analyzed by MALDI-TOF mass spectrometry. The proteins were then identified by comparing in silico digestion of proteins contained in the databank and the experimental spectra using a search engine; in our case the local version of the Mascot software was used. NanoLC nano-ESI MS/MS experiments were performed on a 9.4 Tesla FT-ICR MS instrument allowing sequencing peptides for identification confirmation. The results obtained using the exposed strategy revealed that several hundred proteins are differentially expressed and that there are several dozen changes in post-translational modification profiles. The analysis of the most intense differentially expressed proteins shows that all the identified proteins behave to the oxidative stress pathway, for example the proteins HspB1: (Heat-shock protein Beta 1) which is known for its implication in the oxidative stress response related to its "chaperone" activity. Now, the study of protein post-translational modifications via the analysis of generated peptides from different enzymes and chemical treatments is under investigation. Moreover, dose-response relationships will be analyzed.