TY  - JOUR
TI  - Sialylation regulates galectin-3/ligand interplay during mammary tumour progression - a case of targeted uncloaking
AU  - de Oliveira, Joana-Tavares
AU  - de Matos, Augusto-José
AU  - Santos, AnaL.
AU  - Pinto, Rita
AU  - Gomes, Joana
AU  - Hespanhol, Venceslau
AU  - Chammas, Roger
AU  - Manninen, Aki
AU  - Bernardes, EmersonS.
AU  - Albuquerque Reis, Celso
AU  - Rutteman, Gerard
AU  - Gärtner, Fátima
T2  - The International Journal of Developmental Biology
AB  - Galectin-3 is involved both in facilitating detachment of cells from primary tumour sites and favouring cancer cell adhesion and survival to anoikis in the blood stream. The mechanisms behind these apparently contradictory roles of the lectin have not yet been resolved. In order to investigate possible interplays between galectin-3 and its ligands underlying their role in the metastatic process, we examined mucin-1 (MUC1) and epidermal growth factor receptor (EGFR), well-known galectin-3 ligands, as well as galectin-3-binding site expression in a series of spontaneous canine malignant mammary tumours (CMMT) and a metastatic CMMT cell line. Despite the fact that CMMT cells expressed MUC1 and EGFR homogeneously over their plasma membrane, intravascular tumour cells, positive for galectin-3, expressed MUC1 and EGFR in a more focal membrane localization. Moreover, MUC1 overexpression in primary CMMT was present in parallel with down-regulation of galectin-3. Furthermore, in the CMT-U27 cell line, galectin-3 knock-down led to increased MUC1 expression, while MUC1 knock-down led to down-regulation of the lectin. Finally, removal of sialic acid from both CMMT and CMT-U27 xenograft samples exposed galectin-3-ligands throughout the tumour tissue, whereas these ligands were only present in galectin-3-positive invading cells in untreated samples. Interestingly indeed, we show that in vessel-invading cells, there is interaction between galectin-3 and the T antigen in vivo. We therefore hypothesized that loss of galectin-3 and sialylation-related masking of its ligands, in conjunction with their overexpression in specific tumour cell subpopulations, are crucial in regulating adhesive/de-adhesive events in the progression and invasive capacity of metastatic cells.
PY  - 2011
DO  - 10.1387/ijdb.113359jt
VL  - 55
IS  - 7-8-9
SP  - 823
EP  - 834
J2  - Int. J. Dev. Biol.
LA  - en
SN  - 0214-6282
SN  - 1696-3547
UR  - https://ijdb.ehu.eus/article/113359jt
Y2  - 2024/11/05/15:26:38
ER  -