Roles of galectin-3 in the tumor microenvironment and tumor metabolism

Galectin-3 is expressed in various tissues and plays an important role in the tumor microenvironment (TME). Galectin-3 has been found to be overexpressed in a variety of cancers and is associated with tumor progression and metastasis. Over the past decades, emerging evidence has suggested that the TME may induce galectin-3 expression to maintain cellular homeostasis and promote cell survival. Furthermore, galectin-3 regulates immune cell function to promote tumor-driven immunosuppression through several mechanisms. In the TME, intracellular and extracellular galectin-3 has different functions. In addition, it has been reported that galectin-3 is associated with glycolysis and mitochondrial metabolism in tumors, and it is involved in the regulation of relevant signaling pathways, thus promoting cancer cell survival via adapting to the TME. The aim of the present review was to summarize the current knowledge on galectin-3 production and its function in the TME, its effect on TME immunosuppression, its association with tumor metabolism and relevant signaling pathways, and to report common types of cancer in which galectin-3 is highly expressed, in order to ensure a comprehensive understanding of the critical effects of galectin-3 on tumor progression and metastasis.