Cytoplasmic translocation of nuclear LSD1 (KDM1A) in human hepatoma cells is induced by its inhibitors

AIM: Histone-modifiable lysine-specific demethylase-1 (LSD1/KDM1A) is an oncoprotein upregulated in cancers, including hepatoma. We previously reported that the hepatoma-preventive geranylgeranoic acid (GGA) inhibits KDM1A at the same IC(50) as that of the clinically used tranylcypromine. Here, we report that these inhibitors induce the cytoplasmic translocation of nuclear KDM1A in a human hepatoma-derived cell line. METHODS & RESULTS: Immunofluorescence studies revealed that KDM1A was cytoplasmically localized in HuH-7 cells 3 h after GGA or tranylcypromine addition. However, GGA did not affect the subcellular localization of another histone lysine-specific demethylase, KDM5A. This suggests that GGA-induced translocation is KDM1A specific. CONCLUSION: These data demonstrate, for the first time, that KDM1A inhibitors specifically induce the cytoplasmic translocation of nuclear KDM1A.