Autophagy is decreased in triple-negative breast carcinoma involving likely the MUC1-EGFR-NEU1 signalling pathway.
Fiche publication
Date publication
janvier 2015
Auteurs
Membres identifiés du Cancéropôle Est :
Pr DEBELLE Laurent, Dr GARBAR Christian, Dr SALESSE Stéphanie, Pr BENSUSSAN Armand
Tous les auteurs :
Garbar C, Mascaux C, Giustiniani J, Salesse S, Debelle L, Antonicelli F, Merrouche Y, Bensussan A
Lien Pubmed
Résumé
Triple-negative breast carcinoma (TN) is a heterogeneous cancer type expressing EGFR in 75% of cases. MUC1 is a large type I sialylated glycoprotein comprising two subunits (alpha and beta chains, also called respectively MUC1-VNTR and MUC1-CT), which was found to regulate EGFR activity through endocytic internalisation. Endocytosis and autophagy use the lysosome pathway involving NEU1. Recently, a molecular EGFR-MUC1-NEU1 complex was suggested to play a role in EGFR pathway. In the aim to understand the relationship between EGFR-MUC1-NEU1 complex and autophagy in breast carcinoma, we compared triple negative (TN) showing a high-EGFR expression with luminal (LUM) presenting low-EGFR level. We studied the expression of MUC1-VNTR, MUC1-CT and NEU1 in comparison with those of two molecular actors of autophagy, PI3K (p110beta) and Beclin1. A total of 87 breast cancers were split in two groups following the immunohistochemical classification of breast carcinoma: 48 TN and 39 LUM. Our results showed that TN presented a high expression of EGFR and a low expression of MUC1-VNTR, MUC1-CT, NEU1, Beclin-1 and PI3Kp110beta. Moreover, in TN, a positive statistical correlation was observed between Beclin-1 or PI3Kp110beta and MUC1-VNTR or NEU1, but not with EGFR. In conclusion, our data suggest that autophagy is reduced in TN leading likely to the deregulation of EGFR-MUC1-NEU1 complex and its associated cellular pathways.
Référence
Int J Clin Exp Pathol. 2015 May 1;8(5):4344-55. eCollection 2015.