DIFFERENTIAL GALECTIN-1 BINDING PATTERNS IN HER2+ HUMAN BREAST CANCER CELL LINES DICTATE CANCER STEM CELL-LIKE PHENOTYPE AND MODULATE SENSITIVITY TO TRASTUZUMAB.

CAGNONI, ALEJANDRO J; SALATINO, MARIANA; DALOTTO MORENO, TOMAS; RABINOVICH, GABRIEL A.; PERROTTA, RAMIRO; MARIÑO, KARINA V.

Mar del Plata

Congreso; SAIC/SAI/SAFIS 2018; 2018

SAIC/SAI/SAFIS

Galectins decode glycan-containing information in a number of cell receptors adjusting signaling thresholds and modulating cellular functions. In particular, galectin-1 (Gal1), binds to terminal N-acetyllactosamine residues on glycosylated proteins in the absence of α2-6 sialic acid (SA) capping (Gal1 permissive glycophenotype) promoting tumor immune suppression and sustaining aberrant angiogenesis. Here, we aim to explore the glycosylation signature of HER2+ breast cancer cells to in- vestigate if Gal1 is involved in resistance to trastuzumab (TZ) targeted therapy. Previously, we have demonstrated that TZ sensitive (TZS) BT-474 and SK-BR-3 cell lines exhibited a Gal-1 restrictive glycophenotype (high α2,6 SA capping) compared to TZ resistant (TZR) JIMT-1 cell line. In accordance with the glycophenotype, TZR cell line bound and expressed higher levels of Gal1 when compared to TZS cell lines. Interestingly, knocking down Gal1 sensitized TZR cell line to TZ challenge (p