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

SARRIAS, LUCIANA; ESPELT, MARÍA V.; ELOLA, MARÍA TERESA; SARTI, FLORENCIA; RABINOVICH, GABRIEL A.; FERNANDEZ, MARISA; MALCHIODI, EMILIO L.; TRONCOSO, MARÍA F.

MAR DEL PLATA

Congreso; REUNIÓN CONJUNTA SAIC SAI&FAIC SAFIS 2022; 2022

SOCIEDAD ARGENTINA DE INVESTIGACION CLINICA

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 upregulated in endothelial cells during tumor-related angiogenesis. Here we aimed to study direct, specific and glycan-dependent Gal1/CD13 interaction as well as the role of both proteins in SKHEP1 LSEC proliferation and migration. Gal1 interaction with CD13 was studied by Surface Plasmon Resonance (SPR) on a Biacore T100 system. 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 (CD13 KO, 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 well-established galectin inhibitor, abrogated this interaction while sucrose (1mM), a disaccharide not recognized by galectins, had no effect. Cell proliferation rate (t72h vs. t0 fold-change, MTT assay) in Gal1-silenced (shGal1) SKHEP1 LSEC showed a trend towards a decrease, while CD13 KO cells showed a significant lower rate of cell proliferation (3.43±0.27) versus control cells (scrambled (scr): 4.79±0.14, p