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Galectin-1: biphasic growth regulation of Leydig tumor cells

Verónica A Biron1, M Mercedes Iglesias, María F Troncoso

  • 1Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, (1428) Buenos Aires, Argentina.

Glycobiology
|June 14, 2006
PubMed

Insights

Galectin-1 (Gal-1) has a dual role in Leydig tumor cells. Low concentrations promote proliferation, while high concentrations induce apoptosis via mitochondrial and death receptor pathways, suggesting a novel role in reproductive health.

Area of Science:

  • Endocrinology
  • Cell Biology
  • Reproductive Biology

Background:

  • Galectin-1 (Gal-1) is a beta-galactoside-binding protein with diverse biological roles.
  • Leydig cells are crucial for testosterone production and reproductive function.
  • The role of Gal-1 in Leydig cell physiology is not well understood.

Purpose of the Study:

  • To investigate the effect of Gal-1 on the growth and death of MA-10 tumor Leydig cells.
  • To elucidate the mechanisms by which Gal-1 modulates Leydig cell proliferation and apoptosis.
  • To explore the potential role of Gal-1 in reproductive physiopathology.

Main Methods:

  • Cytofluorometry to detect cytoplasmic Gal-1 expression.
  • Assays for DNA fragmentation, caspase activation (caspase-3, -8, -9), mitochondrial membrane potential (DeltaPsim), and cytochrome c (Cyt c) release.
  • Assessment of FasL expression.
  • Treatment with recombinant Gal-1 (rGal-1) at varying concentrations and with lactose.

Main Results:

  • Cytoplasmic Gal-1 was identified in MA-10 tumor Leydig cells.
  • High concentrations of rGal-1 induced apoptosis through both mitochondrial and death receptor pathways, evidenced by DNA fragmentation, caspase activation, loss of DeltaPsim, Cyt c release, and FasL expression.
  • These apoptotic pathways were independently activated.
  • Low concentrations of Gal-1 significantly promoted cell proliferation without inducing cell death.
  • Lactose inhibited Gal-1 effects, indicating the involvement of its carbohydrate recognition domain (CRD).

Conclusions:

  • Galectin-1 acts as a novel biphasic regulator of Leydig tumor cell number.
  • Gal-1 can promote Leydig cell proliferation at low concentrations and induce apoptosis at high concentrations.
  • The findings suggest a novel role for Gal-1 in reproductive physiopathology.

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