Prognostic impact of T-cell immunoglobulin and mucin domain-3/Galectin-9 expression in acute myeloid leukemia patients

Background T-cell immunoglobulin and mucin domain-3 (TIM-3) is described as a unique Acute myeloid leukemia (AML) stem cell antigen that is not present in normal hematopoietic stem cells. TIM-3 (with its ligand Galectin-9) has gained prominence as an immune checkpoint and plays a vital role in immune responses in AML. TIM-3 and Galectin-9 constitute a pan-myeloid autocrine loop to develop malignant stem cells in AML resulting in a decrease of immune surveillance and promotion of disease progression. We focused in our study on the role of TIM-3/Galectin-9 expression in newly diagnosed AML patients, and their correlation with response to induction chemotherapy. Results Our results showed that TIM-3 and Galectin-9 were significantly higher in the AML patient group compared with the control group ( P = 0.042) and ( P = 0.000), respectively. However, TIM-3/Galectin-9 were not significantly related to other demographic or laboratory data. Furthermore, their expression significantly decreased at day 28 of induction chemotherapy compared with that at initial diagnosis ( P < 0.001). Conclusion We found that TIM-3/Galectin-9 can act as a specific surface molecules expressed in AML leukemic stem cells (LSCs) and their expression can distinguish AML LSCs from normal hematopoietic stem cells (HSCs). So targeting TIM-3/Galectin-9 may be a useful therapeutic approach.