Epigenetic drugs can stimulate metastasis through enhanced expression of the pro-metastatic Ezrin gene.
Ezrin has been reported to be upregulated in many tumors and to participate in metastatic progression. No study has addressed epigenetic modification in the regulation of Ezrin gene expression, the importance of which is unknown. Here, we report that highly metastatic rhabdomyosarcoma (RMS) cells with high levels of Ezrin have elevated acetyl-H3-K9 and tri-methyl-H3-K4 as well as reduced DNA methylation at the Ezrin gene promoter. Conversely, poorly metastatic RMS cells with low levels of Ezrin have reduced acetyl-H3-K9 and elevated methylation. Thus epigenetic covalent modifications to histones within nucleosomes of the Ezrin gene promoter are linked to Ezrin expression, which in fact can be regulated by epigenetic mechanisms. Notably, treatment with histone deacetylase (HDAC) inhibitors or DNA demethylating agents could restore Ezrin expression and stimulate the metastatic potential of poorly metastatic RMS cells characterized by low Ezrin levels. However, the ability of epigenetic drugs to stimulate metastasis in RMS cells was inhibited by expression of an Ezrin-specific shRNA. Our data demonstrate the potential risk associated with clinical application of broadly acting covalent epigenetic modifiers, and highlight the value of combination therapies that include agents specifically targeting potent pro-metastatic genes.
Yu
Yanlin
Y
Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America. YuY@mail.nih.gov
Zeng
Pingyao
P
Xiong
Jingbo
J
Liu
Ziyang
Z
Berger
Shelley L
SL
Merlino
Glenn
G
D000818:Animals; D045744:Cell Line, Tumor; D003598:Cytoskeletal Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects; D044127:Epigenesis, Genetic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008745:Methylation / Q000187:drug effects; D051379:Mice; D009362:Neoplasm Metastasis / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012208:Rhabdomyosarcoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000099149:Ezrin
D003598:Cytoskeletal Proteins; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D000099149:Ezrin