Galectin-1: a small protein with major functions

Abstract

Galectins are a family of carbohydrate-binding proteins with an affinity for beta-galactosides. Galectin-1 (Gal-1) is differentially expressed by various normal and pathological tissues and appears to be functionally polyvalent, with a wide range of biological activity. The intracellular and extracellular activity of Gal-1 has been described. Evidence points to Gal-1 and its ligands as one of the master regulators of such immune responses as T-cell homeostasis and survival, T-cell immune disorders, inflammation and allergies as well as host-pathogen interactions. Gal-1 expression or overexpression in tumors and/or the tissue surrounding them must be considered as a sign of the malignant tumor progression that is often related to the long-range dissemination of tumoral cells (metastasis), to their dissemination into the surrounding normal tissue, and to tumor immune-escape. Gal-1 in its oxidized form plays a number of important roles in the regeneration of the central nervous system after injury. The targeted overexpression (or delivery) of Gal-1 should be considered as a method of choice for the treatment of some kinds of inflammation-related diseases, neurodegenerative pathologies and muscular dystrophies. In contrast, the targeted inhibition of Gal-1 expression is what should be developed for therapeutic applications against cancer progression. Gal-1 is thus a promising molecular target for the development of new and original therapeutic tools.

Psoriasis in humans is associated with down‐regulation of galectins in dendritic cells

“…The effects of gal-1 on T cells are likely due to the binding of cellsurface glycoproteins on these cells. A number of T cell glycoproteins, including CD2, CD3, CD7, CD45 and CD43 have been shown to act as receptors for gal-1 binding and to be involved in gal-1-mediated T cell death [37]. However, the absence of apoptosis induction under the doses used in our assays suggests a non-apoptotic mechanism and a gal-1 partner on activated T cells not described yet.…”

The Ras‐ERK pathway: Understanding site‐specific signaling provides hope of new anti‐tumor therapies

“…Galectin-1 could be an attractive candidate as it is involved in cancer in many ways [94] and abrogating its function could disrupt Ras signals coming from H-Ras nanoclusters to prevent cellular transformation. [37] However, Galectin-1 seems to be quite pleiotropic, [95] a drawback that must be considered when anticipating potential toxic effects. The case is not so clear with Galectin-3, as its down-regulation potentiates ERK activation and K-RasV12-induced transformation.…”

Presence of galectin-1 in the epidermal and dermal thickening of keloid tissues

“…Gal-1 is a member of the galectin family that has high affinity for N-acetylLactosamine (LacNAc) disaccharides in both Nand O-glycans and is differentially expressed by various normal and pathological tissues [31]. It has been detected in the cell nucleus, cytoplasm and intracellular and extracellular sides of cell membrane, and can be secreted and found in the extracellular space [31].…”

“…Gal-1 is a member of the galectin family that has high affinity for N-acetylLactosamine (LacNAc) disaccharides in both Nand O-glycans and is differentially expressed by various normal and pathological tissues [31]. It has been detected in the cell nucleus, cytoplasm and intracellular and extracellular sides of cell membrane, and can be secreted and found in the extracellular space [31]. Gal-1, like others galectins, participates in signaling pathways and regulates a variety of biological responses including cell growth, cell-cell and cell-matrix adhesion, cell differentiation, migration, proliferation and survival [31][32][33][34] and plays a critical role in inflammation, angiogenesis, and tumor development and progression [27,33,35,36].…”

“…It has been detected in the cell nucleus, cytoplasm and intracellular and extracellular sides of cell membrane, and can be secreted and found in the extracellular space [31]. Gal-1, like others galectins, participates in signaling pathways and regulates a variety of biological responses including cell growth, cell-cell and cell-matrix adhesion, cell differentiation, migration, proliferation and survival [31][32][33][34] and plays a critical role in inflammation, angiogenesis, and tumor development and progression [27,33,35,36]. In human skin, Gal-1 has been implicated in psoriasis [37,38] and malignant lesions including cutaneous cancer [39], mycosis fungoides [40,41], and melanoma [42], and scarce studies have shown that the expression of Gal-1 is upregulated in keloid tissue [43].…”