Galectin-3 Release in the Bone Marrow Microenvironment Promotes Drug Resistance and Relapse in Acute Myeloid Leukemia

Reciprocal signaling between acute myeloid leukemia (AML) cells and the surrounding bone-marrow microenvironment (BMME) promotes AML progression through several mechanisms. One of the most important mechanisms is the induction of Galectin-3 (Gal-3) expression by AML cells and bone marrow mesenchymal stromal cells (BM-MSCs). Emerging evidence indicates that Gal-3 upregulation in the BMME promotes AML cell adhesion and survival, leading to the development of chemotherapy resistance, relapse, and poor prognosis. Identifying the biological function and critical signaling pathways of Gal-3 may contribute to overcoming acquired drug resistance and preventing post-treatment relapse. Gal-3 is involved in several molecular signaling pathways, including PI3K/AKT/mTOR, Ras/Raf/MEK/ERK, JAK/STAT, JNK, Wnt/β-catenin, PLC/PKC and NF-κB, which are interconnected to promote AML cell survival and resistance to chemotherapy. This review focuses on the biological effects, molecular mechanisms of action and regulation of Gal-3 in the pathogenesis and progression of AML. The therapeutic potential of potent synthetic small-molecule Gal-3 inhibitors in high-risk patients with AML is also discussed based on preclinical and clinical evidence from several human diseases. Currently, the effect of these Gal-3 inhibitors in AML has not been investigated either in vitro or in vivo. The findings provide a rationale for targeting Gal-3 that may be a very promising therapeutic approach, especially for patients with relapsed/refractory AML, and may enhance the efficacy of conventional chemotherapeutic drugs and/or immune checkpoint inhibitors.