Proteomics demonstration that normal breast epithelial cells can induce apoptosis of breast cancer cells through insulin-like growth factor-binding protein-3 and maspin.
Normal breast epithelial cells are known to exert an apoptotic effect on breast cancer cells, resulting in a potential paracrine inhibition of breast tumor development. In this study we purified and characterized the apoptosis-inducing factors secreted by normal breast epithelial cells. Conditioned medium was concentrated by ultrafiltration and separated on reverse phase Sep-Pak C18 and HPLC. The proapoptotic activity of eluted fractions was tested on MCF-7 breast cancer cells, and nano-LC-nano-ESI-MS/MS allowed the identification of insulin-like growth factor-binding protein-3 (IGFBP-3) and maspin as the proapoptotic factors produced by normal breast epithelial cells. Western blot analysis of conditioned media confirmed the specific secretion of IGFBP-3 and maspin by normal cells but not by breast cancer cells. Immunodepletion of IGFBP-3 and maspin completely abolished the normal cell-induced apoptosis of cancer cells, and recombinant proteins reproduced the effect of normal cell-conditioned medium on apoptosis of breast cancer cells. Together our results indicated that normal breast epithelial cells can induce apoptosis of breast cancer cells through IGFBP-3 and maspin. These findings provide a molecular hypothesis for the long observed inhibitory effect of normal surrounding cells on breast cancer development.
Toillon
Robert-Alain
RA
INSERM ERI-8 (JE 2488) Signalisation des facteurs de croissance dans le cancer du sein. Protéomique fonctionnelle, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France.
Lagadec
Chann
C
Page
Adeline
A
Chopin
Valérie
V
Sautière
Pierre-Eric
PE
Ricort
Jean-Marc
JM
Lemoine
Jérôme
J
Zhang
Ming
M
Hondermarck
Hubert
H
Le Bourhis
Xuefen
X
D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D017209:Apoptosis / Q000502:physiology*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000502:physiology*; D008969:Molecular Sequence Data; D040901:Proteomics; D015843:Serpins / Q000502:physiology*; D053719:Tandem Mass Spectrometry
D017077:Culture Media, Conditioned; D018972:Insulin-Like Growth Factor Binding Protein 3; C085344:SERPIN-B5; D015843:Serpins