Galectins: Multitask signaling molecules linking fibroblast, endothelial and immune cell programs in the tumor microenvironment.

Tumor cells corrupt surrounding normal cells instructing them to support proliferative, pro-angiogenic and immunosuppressive networks that favor tumorigenesis and metastasis. This dynamic cross-talk is sustained by a range of intracellular signals and extracellular mediators produced by both tumoral and non-tumoral cells. Galectins -whether secreted or intracellularly expressed- play central roles in the tumorigenic process by delivering regulatory signals that contribute to reprogram fibroblasts, endothelial and immune cell programs. Through glycosylation-dependent or independent mechanisms, these endogenous lectins control a variety of cellular events leading to tumor cell proliferation, survival, migration, inflammation, angiogenesis and immune escape. Here we discuss the role of galectin-driven pathways, particularly those activated in non-tumoral stromal cells, in modulating tumor progression.