Mutations in the plant homeodomain-like finger protein 6(PHF6)gene are strongly associated with acute myeloid(AML)and T-cell acute lymphoblastic leukemia(T-ALL).In this study,we demonstrated that PHF6 can bind to H3K9...Mutations in the plant homeodomain-like finger protein 6(PHF6)gene are strongly associated with acute myeloid(AML)and T-cell acute lymphoblastic leukemia(T-ALL).In this study,we demonstrated that PHF6 can bind to H3K9me3 and H3K27me1 on the nucleolar chromatin and recruit histone methyltransferase SUV39H1 to the rDNA locus.The deletion of PHF6 caused a decrease in the recruitment of SUV39H1 to rDNA gene loci,resulting in a reduction in the level of H3K9me3 and the promotion of rDNA transcription.The knockdown of either SUV39H1 or PHF6 significantly attenuated the effects of increase in H3K9me3 and suppressed the transcription of rDNA induced by the overexpression of the other interacting partner,thereby establishing an interdependent relationship between PHF6 and SUV39H1 in their control of rRNA transcription.The PHF6 clinical mutants significantly impaired the ability to bind and recruit SUV39H1 to the rDNA loci,resulting in an increase in rDNA transcription activity,the proliferation of in vitro leukemia cells,and the growth of in vivo mouse xenografts.Importantly,significantly elevated levels of pre-rRNA were observed in clinical AML patients who possessed a mutated version of PHF6.The specific rDNA transcription inhibitor CX5461 significantly reduced the resistance of U937 AML cells deficient in PHF6 to cytarabine,the drug that is most commonly used to treat AML.Collectively,we revealed a novel molecular mechanism by which PHF6 recruits methyltransferase SUV39H1 to the nucleolar region in leukemia and provided a potential therapeutic target for PHF6-mutant leukemia.展开更多
基金supported by the National Natural Science Foundation of China (81702750, 81670141, 81970145and 82001698)Natural Science Foundation of Guangdong Province (2020A1515011465and 2020A151501467, China)+5 种基金Science, Technology & Innovation Commission of Shenzhen Municipality ( JCYJ20180307154700308, JCYJ20170818163844015, JCYJ20180307151420045, JCYJ20190807151609464, JCYJ20200109142605909 and JCYJ20210324120007020, China)Sun Yat-sen University (20ykzd17 and 20ykpy122, China)International Collaboration of Science and Technology of Guangdong Province (2020A0505100031, China)Guangdong Provincial Key Laboratory of Digestive Cancer Research (No.2021B1212040006,China)The Social Development Foundation of Jiangsu Province (BE2018691, China)Sigrid Jusélius foundation in Finland for funding the project (Finland)
文摘Mutations in the plant homeodomain-like finger protein 6(PHF6)gene are strongly associated with acute myeloid(AML)and T-cell acute lymphoblastic leukemia(T-ALL).In this study,we demonstrated that PHF6 can bind to H3K9me3 and H3K27me1 on the nucleolar chromatin and recruit histone methyltransferase SUV39H1 to the rDNA locus.The deletion of PHF6 caused a decrease in the recruitment of SUV39H1 to rDNA gene loci,resulting in a reduction in the level of H3K9me3 and the promotion of rDNA transcription.The knockdown of either SUV39H1 or PHF6 significantly attenuated the effects of increase in H3K9me3 and suppressed the transcription of rDNA induced by the overexpression of the other interacting partner,thereby establishing an interdependent relationship between PHF6 and SUV39H1 in their control of rRNA transcription.The PHF6 clinical mutants significantly impaired the ability to bind and recruit SUV39H1 to the rDNA loci,resulting in an increase in rDNA transcription activity,the proliferation of in vitro leukemia cells,and the growth of in vivo mouse xenografts.Importantly,significantly elevated levels of pre-rRNA were observed in clinical AML patients who possessed a mutated version of PHF6.The specific rDNA transcription inhibitor CX5461 significantly reduced the resistance of U937 AML cells deficient in PHF6 to cytarabine,the drug that is most commonly used to treat AML.Collectively,we revealed a novel molecular mechanism by which PHF6 recruits methyltransferase SUV39H1 to the nucleolar region in leukemia and provided a potential therapeutic target for PHF6-mutant leukemia.
