Targeting FHL1 impairs cell proliferation and differentiation of acute myeloid leukemia cells.

The four and a half LIM domains 1 (FHL1) is considered to play important roles in tumors. This study aims to investigate the role and precise mechanisms of FHL1 in acute myeloid leukemia (AML). Here, we found that FHL1 was highly expressed in AML. CCK8, flow cytometry, and Western blot analysis of cell cycle-related proteins showed that overexpression of FHL1 promoted proliferation and accelerated cell cycle progression in HL-60 cells. Conversely, knockdown of FHL1 inhibited the proliferation and induced cell cycle arrest in KG-1 cells. Furthermore, knockdown of FHL1 promoted cell differentiation, while overexpression of FHL1 restrained all-trans retinoic acid induced cell differentiation in HL-60 cells, revealed by Wright-Giemsa staining and cell surface antigen analysis. Moreover, in vivo experiments revealed that depletion of FHL1 inhibited tumor growth and led to increased levels of CD11b and CD14. Here, we first identify an unexpected and important role of FHL1 that contributes to the AML progression, indicating that FHL1 may be a potential therapeutic target for AML.