• Galectin-1 and its ovel ligand CD13 in liver tumor-derived sinusoidal endothelial cells

SARRIAS L; FERNÁNDEZ, MM; SARTI, F; ESPELT, MV; MALCHIODI EL; RABINOVICH GA; ELOLA, MT; TRONCOSO, MARÍA F.

Mar del Plata

Congreso; Reunion conjunta SAIC-SAFIS-SAI; 2022

Galectin-1 (Gal1), a β-galactoside-binding protein, is upregulated in hepatocellular carcinoma. Previously we identified CD13 as a ligand for Gal1 in human SKHEP1 liver tumor-derived sinusoidal endothelial cells (LSEC) using a proteomic approach. CD13 is a glycosylated membrane exopeptidase increased in endothelial cells during tumor-related angiogenesis. Here we aimed to confirm direct, specific and glycan-dependent Gal1/CD13 interaction and the role of both proteins in SKHEP1 LSEC proliferation and migration. Gal1 interaction with CD13 was studied by Surface Plasmon Resonance (SPR). CD13 was isolated from SKHEP1 LSEC membrane fraction using a Gal1-affinity column and coupled to a sensor chip CM5. Human recombinant Gal1 (0.075-20µM) was injected in each cycle. As a blank, a fraction of membrane proteins isolated from CD13 knockout (KOCD13, CRISPR-Cas9-based) SKHEP1 LSEC was immobilized on another chip. SPR assays confirmed Gal1 and CD13 interaction (Dissociation constant, KD: 3.1±0.2 x 10-6M). Preincubation with 1mM lactose, a known galectin inhibitor, abrogated the interaction while a disaccharide not recognized by galectins, sucrose (1mM), had no effect on Gal1/CD13 interaction. Cell proliferation rate (72h, MTT assay) in Gal1-silenced (shGal1) SKHEP1 LSEC showed a decreasing trend, while a significant decrease (3.43±0.27 folds) was observed in KOCD13 SKHEP1 cells (scrambled (scr): 4.79±0.14, p