Expression of delta-lactoferrin induces cell cycle arrest.
Delta-lactoferrin (deltaLf) mRNA is the product of alternative splicing of the Lf gene. It has been found in normal tissues and was reported to be absent from their malignant counterparts. Our recent investigations have shown that deltaLf expression is a good prognostic indicator in human breast cancer. However, deltaLf has up till now only been identified as a transcript, and in order to characterize the deltaLf protein and determine its function we have used a deltaLf cDNA construct to produce the protein in vitro and in vivo. A 73 kDa protein was immunoprecipitated from in vitro translation products and this molecular weight is in accordance with the use of the first in frame AUG start codon located in exon 2. We also produced a cell line expressing deltaLf under doxycycline induction. Using this model we have been able to show that deltaLf is mainly distributed in the cytoplasm. Its expression induces cell cycle arrest and inhibits cell proliferation. Our results suggest that deltaLf may play an important role in the regulation of normal cell growth.
Breton
Mathilde
M
Unité de Glycobiologie Structurale et Fonctionnelle, Institut Fédératif de Recherche no 118, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq cedex, France.
Mariller
Christophe
C
Benaïssa
Monique
M
Caillaux
Katia
K
Browaeys
Edith
E
Masson
Maryse
M
Vilain
Jean-Pierre
JP
Mazurier
Joël
J
Pierce
Annick
A
D017398:Alternative Splicing; D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D002460:Cell Line; D002474:Cell-Free System; D005091:Exons; D006801:Humans; D007781:Lactoferrin / Q000235:genetics* / Q000378:metabolism*; D014176:Protein Biosynthesis; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism*; D020871:RNA Stability; D014982:Xenopus laevis
D020033:Protein Isoforms; D007781:Lactoferrin