MLL Histone Methylases in Estrogen-Mediated Regulation of HOX Genes Involved in Hair Follicle Development and Leukemia

The study explored the role of mixed lineage leukemias (MLLs), which are histone H3 lysine 4 specific methyl-transferases, in the regulation of HOX genes, particularly focusing on HOXC13. HOXC13 is crucial for hair follicle development and leukemia. The research demonstrated that estrogen (E2) transcriptionally regulated HOXC13, with estrogen receptors (ERs) binding to estrogen response elements (EREs) on the HOXC13 promoter. Knockdown experiments showed that both ERs and the histone methylase MLL3 were necessary for E2-induced activation of HOXC13. These findings highlighted the importance of MLL-histone methylases and ERs in regulating HOXC13 expression, implicating their significant roles in hair follicle development and associated diseases.