title: SILAC-based proteomic profiling of the human MDA-MB-231 metastatic breast cancer cell line in response to the two antitumoral lactoferrin isoforms: the secreted lactoferrin and the intracellular delta-lactoferrin.
abstract: BACKGROUND
  Lactoferrins exhibit antitumoral activities either as a secretory lactoferrin or an intracellular delta-lactoferrin isoform. These activities involve processes such as regulation of the cell cycle and apoptosis. While lactoferrin has been shown to exert its function by activating different transduction pathways, delta-lactoferrin has been proven to act as a transcription factor. Like many tumor suppressors, these two proteins are under-expressed in several types of cancer, particularly in breast cancer.
  
  
  RESULTS
  In order to compare the differential effects of the re-introduction of lactoferrin isoforms in breast cancer cells we chose the cancerous mammary gland MDA-MB-231 cell line as a model. We produced a cell line stably expressing delta-lactoferrin. We also treated these cells with fresh purified human breast lactoferrin. We performed two quantitative proteomic studies in parallel using SILAC coupled to mass spectrometry in order to compare the effects of different doses of the two lactoferrin isoforms. The proteome of untreated, delta-lactoferrin expressing and human lactoferrin treated MDA-MB-231 cells were compared. Overall, around 5300 proteins were identified and quantified using the in-house developed MFPaQ software. Among these, expression was increased by 1.5-fold or more for around 300 proteins in delta-lactoferrin expressing cells and 190 proteins in lactoferrin treated cells. At the same time, about 200 and 40 proteins were found to be downregulated (0-0.7-fold) in response to delta-lactoferrin and lactoferrin, respectively.
  
  
  CONCLUSIONS
  Re-introduction of delta-lactoferrin and lactoferrin expression in MDA-MB-231 mainly leads to modifications of protein profiles involved in processes such as proliferation, apoptosis, oxidative stress, the ubiquitin pathway, translation and mRNA quality control. Moreover, this study identified new target genes of delta-lactoferrin transcriptional activity such as SelH, GTF2F2 and UBE2E1.
authors.affiliation: UGSF, UMR 8576 CNRS, USTL, IFR 147, Villeneuve d'Ascq, France.
authors.forename: Esthelle
authors.initials: E
authors.lastname: Hoedt
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France; Université de Toulouse, UPS, IPBS, Toulouse, France.
authors.forename: Karima
authors.initials: K
authors.lastname: Chaoui
authors.affiliation: UGSF, UMR 8576 CNRS, USTL, IFR 147, Villeneuve d'Ascq, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Huvent
authors.affiliation: UGSF, UMR 8576 CNRS, USTL, IFR 147, Villeneuve d'Ascq, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Mariller
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France; Université de Toulouse, UPS, IPBS, Toulouse, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Monsarrat
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France; Université de Toulouse, UPS, IPBS, Toulouse, France.
authors.forename: Odile
authors.initials: O
authors.lastname: Burlet-Schiltz
authors.affiliation: UGSF, UMR 8576 CNRS, USTL, IFR 147, Villeneuve d'Ascq, France.
authors.forename: Annick
authors.initials: A
authors.lastname: Pierce
mesh_terms: D017398:Alternative Splicing; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007553:Isotope Labeling; D007781:Lactoferrin / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D009362:Neoplasm Metastasis; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020033:Protein Isoforms; D020543:Proteome; D040901:Proteomics / Q000379:methods; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D015203:Reproducibility of Results; D020218:Response Elements; D051140:Selenoproteins / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D019473:Transcription Factors, TFII / Q000235:genetics / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D020543:Proteome; D011994:Recombinant Proteins; D051140:Selenoproteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C489963:UBE2E1 protein, human; D044763:Ubiquitin-Conjugating Enzymes; D007781:Lactoferrin; C056604:transcription factor TFIIF