title: Galectin-1: biphasic growth regulation of Leydig tumor cells.
abstract: Galectin-1 (Gal-1) is a widely expressed beta-galactoside-binding protein that exerts pleiotropic biological functions. To gain insight into the potential role of Gal-1 as a novel modulator of Leydig cells, we investigated its effect on the growth and death of MA-10 tumor Leydig cells. In this study, we identified cytoplasmic Gal-1 expression in these tumor cells by cytofluorometry. DNA fragmentation, caspase-3, -8, and -9 activation, loss of mitochondrial membrane potential (DeltaPsim), cytochrome c (Cyt c) release, and FasL expression suggested that relatively high concentrations of exogenously added recombinant Gal-1 (rGal-1) induced apoptosis by the mitochondrial and death receptor pathways. These pathways were independently activated, as the presence of the inhibitor of caspase-8 or -9 only partially prevented Gal-1-effect. On the contrary, low concentrations of Gal-1 significantly promoted cell proliferation, without inducing cell death. Importantly, the presence of the disaccharide lactose prevented Gal-1 effects, suggesting the involvement of the carbohydrate recognition domain (CRD). This study provides strong evidence that Gal-1 is a novel biphasic regulator of Leydig tumor cell number, suggesting a novel role for Gal-1 in the reproductive physiopathology.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, (1428) Buenos Aires, Argentina.
authors.forename: Verónica A
authors.initials: VA
authors.lastname: Biron
authors.forename: M Mercedes
authors.initials: MM
authors.lastname: Iglesias
authors.forename: María F
authors.initials: MF
authors.lastname: Troncoso
authors.forename: Marcos
authors.initials: M
authors.lastname: Besio-Moreno
authors.forename: Zoraida J
authors.initials: ZJ
authors.lastname: Patrignani
authors.forename: Omar P
authors.initials: OP
authors.lastname: Pignataro
authors.forename: Carlota
authors.initials: C
authors.lastname: Wolfenstein-Todel
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism / Q000473:pathology; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D037483:Galectin 1 / Q000096:biosynthesis / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D007785:Lactose / Q000494:pharmacology; D007985:Leydig Cells / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D018310:Sertoli-Leydig Cell Tumor / Q000378:metabolism* / Q000473:pathology; D013736:Testicular Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D037483:Galectin 1; D009363:Neoplasm Proteins; D007785:Lactose