Unraveling the role of prohibitin-1, a novel ligand of galectin-1 in hepatocellular carcinoma cell viability

CARABIAS, P; PASQUINI, L; BACIGALUPO, ML; WOLFENSTEIN-TODEL, C; TRONCOSO, MF; OTERO, S; ELOLA, MT; ESPELT, MV

Buenos aires

Congreso; Reunión conjunta de sociedades de biociencias; 2017

Galectin-1 (Gal1) is a glycan-binding protein overexpressed in hepatocellular carcinoma (HCC). We demonstrated that Gal1 upregulation in human HCC cells induces cell proliferation, epithelial-mesenchymal transition, tumor growth and metastasis. By proteomics we have identified prohibitin-1 (PHB) as a new Gal1 ligand in HCC cells. PHB has multiple functions depending on its subcellular localization. Its role in cancer is controversial, it was found downregulated in most human HCC tissues analyzed but in other HCC samples its overexpression was observed. Liver-specific PHB knockout (KO) mice develop HCC spontaneously suggesting that PHB functions as tumor suppressor, although when highly expressed it promotes HCC cell migration in vitro showing its involvement in tumor progression. Thus, we aimed to elucidate PHB role in HCC cell viability and to analyze if PHB expression is regulated by Gal1. By immunofluorescence, we observed that PHB localizes in a punctate pattern in human HepG2 and HuH-7 HCC cells, both in nucleus and cytoplasm. By siRNA transfection, we downregulated PHB expression in these cells: HepG2-siPHB 31±15 vs HepG2-siControl 76±19% (p