Galectins: matricellular glycan-binding proteins linking cell adhesion, migration, and survival

Abstract

Galectins are a taxonomically widespread family of glycan-binding proteins, defined by at least one conserved carbohydrate-recognition domain with a canonical amino acid sequence and affinity for beta-galactosides. Because of their anti-adhesive as well as pro-adhesive extracellular functions, galectins appear to be a novel class of adhesion-modulating proteins collectively known as matricellular proteins (which include thrombospondin, SPARC, tenascin, hevin, and disintegrins). Accordingly, galectins can display de-adhesive effects when presented as soluble proteins to cells in a strong adhesive state. In this context, the de-adhesive properties of galectins should be considered as physiologically relevant as the proadhesive effects of these glycan-binding proteins. This article focuses on the roles of mammalian galectins in cell adhesion, spreading, and migration, and the crossregulation of these functions. Although careful attention should be paid when examining individual galectin functions due to overlapping distributions, these intriguing glycan-binding proteins offer promising possibilities for the treatment and intervention of a wide variety of pathological processes, including cancer, inflammation, and autoimmunity.

Targeting Activating Transcription Factor 3 by Galectin-9 Induces Apoptosis and Overcomes Various Types of Treatment Resistance in Chronic Myelogenous Leukemia

“…Among 14 mammalian galectins, galectin-9 (Gal9) has been shown to possess the anticancer properties by regulating various cellular functions, such as cell adhesion, cell proliferation, or apoptosis (8)(9)(10)(11)(12). These prompted us to investigate whether Gal9 can have an anti-CML effect through signaling cascades distinct from the pathway used by Bcr-Abl TKIs or by other commonly used anticancer agents.…”

Extracellular influences on tumour angiogenesis in the aged host

“…In aged tissues, the complexities surrounding the role of SPARC in the angiogenic response are obviated by age-related deficits in the levels of growth factors and other pro-angiogenic mediators (Reed et al, 2005). Nevertheless, the relative ease by which in vivo SPARC expression can be manipulated has resulted in continued enthusiasm for its therapeutic potential in highly vascularized tumours (Elola et al, 2007).…”

Redundant and Antagonistic Functions of Galectin-1, -3, and -8 in the Elicitation of T Cell Responses

“…G alectins (Gals) constitute a family of secreted mammalian lectins with affinity for b-galactosides that bind glycoreceptors on target cells and induce multiple biological activities that include a broad spectrum of cellular responses, such as proliferation, apoptosis, differentiation, adhesion, migration, and cytokine secretion (1,2). Gals are characterized by the presence of conserved carbohydrate-recognition domains (CRDs) and are structurally classified into three subgroups: prototype (one CRD, such as Gal-1, -2, and -7), tandem repeat (two linked CRDs, such as Gal-4, -8, and -9), and chimera (one CRD fused to a nonlectin domain; Gal-3).…”