In the last decades, the focus of cancer research has moved from epithelial cells to the tumor milieu, in an effort to better understand tumor development and progression, and with the important end goal of translating this knowledge into effective therapies. The galectin family of glycan-binding proteins displays important functions in cancer development and progression. Numerous groups have made outstanding contributions to deepen our knowledge about the role of galectins in the tumor-stroma crosstalk, defining them as key players in modulating interactions between tumor cells and the extracellular matrix, fibroblasts, endothelium, and the immune system. While several members of the family have been of particular interest until now, others are still considered as future exploding stars. This chapter provides an overview for galectin-1, the first identified and still one of the most well-studied galectins, and highlights the very important implications in its regulation of the tumor microenvironment in many different tumor types. Besides, a glimpse of the role of other galectins in the tumor milieu is also provided. Gaining a deeper understanding about the numerous roles of galectin-1 will not only help us to better understand other galectins but also is likely to result in the development of more effective cancer therapies.
Keywords: Angiogenesis; Cancer therapy; Fibroblast activation; Galectin-1; Galectins; Immune evasion; Tumor microenvironment; Tumor-stroma crosstalk.