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
Clear cell renal cell carcinoma(ccRCC)is a common kidney malignancy characterized by a poor prognosis.Suppressor of variegation 3-9 homolog 1(SUV39H1),which encodes a histone H3 lysine 9 methyltransferase,has been rep...Clear cell renal cell carcinoma(ccRCC)is a common kidney malignancy characterized by a poor prognosis.Suppressor of variegation 3-9 homolog 1(SUV39H1),which encodes a histone H3 lysine 9 methyltransferase,has been reported to act as an oncogene in many cancers.However,it is unclear whether SUV39H1 is involved in ccRCC.Here,we report that SUV39H1 expression is frequently upregulated in ccRCC tumors and is significantly correlated with ccRCC progression.SUV39H1 expression level is an independent risk factor for cancer prognosis,and integration with several known prognostic factors predicted ccRCC patient prognosis with improved accuracy than the conventional SSIGN(stage,size,grade and necrosis)prognostic model.Mechanistically,we discovered that siRNA knockdown or pharmacological inhibition of SUV39 H1 induced iron accumulation and lipid peroxidation,leading to ferroptosis that disrupted ccRCC cell growth in vitro and in vivo.We also show that SUV39H1 deficiency modulated the H3K9me3 status of the DPP4(dipeptidyl-peptidase-4)gene promoter,resulting in upregulation of its expression that contributes to ferroptosis.Taken together,our findings provide the mechanistic insight into SUV39H1-dependent epigenetic control of ccRCC tumor growth and indicate that SUV39H1 may serve as a potential therapeutic target for ccRCC treatment.展开更多
目的应用小干扰RNA（siRNA）干扰人急性髓系白血病细胞株KG-1细胞SUV39H1（suppressor of variegation 3-9 homolog1）基因的表达，研究SUV39H1基因沉默对KG一1细胞增殖、抑癌基因p15表达及组蛋白甲基化、乙酰化修饰的影响，探寻白血病...目的应用小干扰RNA（siRNA）干扰人急性髓系白血病细胞株KG-1细胞SUV39H1（suppressor of variegation 3-9 homolog1）基因的表达，研究SUV39H1基因沉默对KG一1细胞增殖、抑癌基因p15表达及组蛋白甲基化、乙酰化修饰的影响，探寻白血病基因治疗的新靶点。方法用Lipo．feetamineTM2000将体外合成针对SUV39H1基因的siRNA片段转染到KG-1细胞后，采用RT—PCR方法检测siRNA对SUV39H1mRNA表达的抑制效果，用四唑氮化合物（MTS）法绘制细胞增殖抑制曲线，Westernblot法检测目的基因SUV39H1和抑癌基因p15的表达及对组蛋白甲基化、乙酰化修饰的影响。结果SUV39H1siRNA转染KG-1细胞可沉默该基因；沉默SUV39H1基因表达可抑制细胞增殖，30、60、120、240nmol／LSUV39H1siRNA转染48h后，KG-1细胞的增殖抑制率分别为（23．57±1．98）％、（48．69±1．84）％、（62．69±1．61）％、（81．06±3．22）％，差异有统计学意义（P〈0．05）；沉默SUV39H1基因可上调p15基因的表达，下调组蛋白H3K9三甲基化，上调组蛋白H3K9、H3的乙酰化。30、60、120nmol／LSUV39H1siRNA处理KG-1细胞48h后，组蛋白H3K9三甲基化水平较对照组分别减少25％、33％、49％；组蛋白H3K9乙酰化水平增强，分别为对照组的1．83、2．16、3．07倍；组蛋白H3乙酰化水平逐渐升高为对照组的1．35、1．87、2．37倍；p15表达水平呈递增趋势，分别为对照组的1．52、2．89、3．08倍；而组蛋白H4、H3K14、H3K27的乙酰化水平未见显著变化。结论沉默SUV39H1基因表达可能通过改变抑癌基因启动子区域的组蛋白修饰，即上调组蛋白H3K9乙酰化及下调H3K9甲基化，使p15基因重新表达，从而抑制细胞增殖。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.
基金supported by the advanced technology promotion project of Shanghai Municipal Commission of Health and Family Planning(No.27 HYR 2013,China)Doctoral Innovation Fund Projects from Shanghai Jiao Tong University School of Medicine(BXJ201919,China)
文摘Clear cell renal cell carcinoma(ccRCC)is a common kidney malignancy characterized by a poor prognosis.Suppressor of variegation 3-9 homolog 1(SUV39H1),which encodes a histone H3 lysine 9 methyltransferase,has been reported to act as an oncogene in many cancers.However,it is unclear whether SUV39H1 is involved in ccRCC.Here,we report that SUV39H1 expression is frequently upregulated in ccRCC tumors and is significantly correlated with ccRCC progression.SUV39H1 expression level is an independent risk factor for cancer prognosis,and integration with several known prognostic factors predicted ccRCC patient prognosis with improved accuracy than the conventional SSIGN(stage,size,grade and necrosis)prognostic model.Mechanistically,we discovered that siRNA knockdown or pharmacological inhibition of SUV39 H1 induced iron accumulation and lipid peroxidation,leading to ferroptosis that disrupted ccRCC cell growth in vitro and in vivo.We also show that SUV39H1 deficiency modulated the H3K9me3 status of the DPP4(dipeptidyl-peptidase-4)gene promoter,resulting in upregulation of its expression that contributes to ferroptosis.Taken together,our findings provide the mechanistic insight into SUV39H1-dependent epigenetic control of ccRCC tumor growth and indicate that SUV39H1 may serve as a potential therapeutic target for ccRCC treatment.
文摘目的应用小干扰RNA（siRNA）干扰人急性髓系白血病细胞株KG-1细胞SUV39H1（suppressor of variegation 3-9 homolog1）基因的表达，研究SUV39H1基因沉默对KG一1细胞增殖、抑癌基因p15表达及组蛋白甲基化、乙酰化修饰的影响，探寻白血病基因治疗的新靶点。方法用Lipo．feetamineTM2000将体外合成针对SUV39H1基因的siRNA片段转染到KG-1细胞后，采用RT—PCR方法检测siRNA对SUV39H1mRNA表达的抑制效果，用四唑氮化合物（MTS）法绘制细胞增殖抑制曲线，Westernblot法检测目的基因SUV39H1和抑癌基因p15的表达及对组蛋白甲基化、乙酰化修饰的影响。结果SUV39H1siRNA转染KG-1细胞可沉默该基因；沉默SUV39H1基因表达可抑制细胞增殖，30、60、120、240nmol／LSUV39H1siRNA转染48h后，KG-1细胞的增殖抑制率分别为（23．57±1．98）％、（48．69±1．84）％、（62．69±1．61）％、（81．06±3．22）％，差异有统计学意义（P〈0．05）；沉默SUV39H1基因可上调p15基因的表达，下调组蛋白H3K9三甲基化，上调组蛋白H3K9、H3的乙酰化。30、60、120nmol／LSUV39H1siRNA处理KG-1细胞48h后，组蛋白H3K9三甲基化水平较对照组分别减少25％、33％、49％；组蛋白H3K9乙酰化水平增强，分别为对照组的1．83、2．16、3．07倍；组蛋白H3乙酰化水平逐渐升高为对照组的1．35、1．87、2．37倍；p15表达水平呈递增趋势，分别为对照组的1．52、2．89、3．08倍；而组蛋白H4、H3K14、H3K27的乙酰化水平未见显著变化。结论沉默SUV39H1基因表达可能通过改变抑癌基因启动子区域的组蛋白修饰，即上调组蛋白H3K9乙酰化及下调H3K9甲基化，使p15基因重新表达，从而抑制细胞增殖。
