本研究旨在探讨慢性淋巴细胞白血病(CLL)患者鼠双微体4(MDM4)基因mRNA的表达情况及其在CLL预后中的意义。采用SYBR Green I荧光染料行实时定量逆转录PCR(qRT-PCR)方法检测66例CLL患者白血病细胞MDM4 mRNA的表达,以β-actin为内参照物,以...本研究旨在探讨慢性淋巴细胞白血病(CLL)患者鼠双微体4(MDM4)基因mRNA的表达情况及其在CLL预后中的意义。采用SYBR Green I荧光染料行实时定量逆转录PCR(qRT-PCR)方法检测66例CLL患者白血病细胞MDM4 mRNA的表达,以β-actin为内参照物,以2(-△Ct)方法计算MDM4的相对定量值,组间分析采用秩和检验。结果显示,66例CLL患者MDM4 mRNA相对表达水平的中位数为0.037098(0.088245-0.014875);具有P53基因缺失的CLL患者,其MDM4的表达明显高于无P53基因缺失的患者(0.13167 vs 0.030927)(p<0.001),具有P53基因突变的CLL患者MDM4 mRNA表达也明显高于无P53基因突变的患者(0.13167 vs0.03077)(p<0.001);此外,MDM4 mRNA的表达水平还与Binet分期(p=0.044)和ATM基因缺失(p=0.046)显著相关,但与血清乳酸脱氢酶(LDH)(p=0.216)、β2-微球蛋白(β2-MG)(p=0.314)、胸苷激酶(TK)1(p=0.300)、ZAP-70(p=0.559)、CD38(p=0.513)和免疫球蛋白重链可变区(IgVH)基因突变状态(p=0.333)无显著相关性。结论:MDM4的表达与P53基因异常关系密切,与Binet分期和ATM基因缺失相关,MDM4可能在CLL的预后中具有重要价值。展开更多
0 引言
Shvarts et al[1]报告了一种与p53蛋白结合蛋白的新基因,命名为MDMX,与MDM2蛋白在一级结构上具有同源性,特别是在p53蛋白结合域更是如此.另外,MDM2羧基末端的金属结合域在MDMX分子中也是高度保守的.MDMX蛋白又称为MDM4,是p53的...0 引言
Shvarts et al[1]报告了一种与p53蛋白结合蛋白的新基因,命名为MDMX,与MDM2蛋白在一级结构上具有同源性,特别是在p53蛋白结合域更是如此.另外,MDM2羧基末端的金属结合域在MDMX分子中也是高度保守的.MDMX蛋白又称为MDM4,是p53的一种结合蛋白,是p53蛋白的负调节因子.展开更多
Mdm2 and Mdm4 are two key negative regulators of the tumor suppressor p53.Deletion of either Mdm2 or Mdm4 induces p53-dependent early embryonic lethality in knockout mouse models.The tissuespecific deletion of Mdm2 in...Mdm2 and Mdm4 are two key negative regulators of the tumor suppressor p53.Deletion of either Mdm2 or Mdm4 induces p53-dependent early embryonic lethality in knockout mouse models.The tissuespecific deletion of Mdm2 induces p53-dependent apoptosis,whereas the deletion of Mdm4 induces both p53-dependent apoptosis and cell cycle arrest.Compared to Mdm4 deletion,Mdm2 deletion causes more severe phenotypic defects.Disrupting the Mdm2 and Mdm4 interaction using knockin mice models causes embryonic lethality that can be completely rescued by the concomitant loss of p53,suggesting that Mdm2 and Mdm4 heterodimerization is critical to inhibit p53 activity during embryogenesis.Overexpression of Mdm2 and Mdm4 in mice induces spontaneous tumorigenesis,which clearly indicates that Mdm2 and Mdm4 are bona fide oncogenes.Studies from these mouse models strongly suggest that blocking Mdm2and Mdm4-mediated p53 inhibition is an appealing therapeutic strategy for cancer patients with wild-type p53 alleles.展开更多
The mouse double minute 4(MDM4)is emerging from the shadow of its more famous relative MDM2 and is starting to steal the limelight,largely due to its therapeutic possibilities.MDM4 is a vital regulator of the tumor su...The mouse double minute 4(MDM4)is emerging from the shadow of its more famous relative MDM2 and is starting to steal the limelight,largely due to its therapeutic possibilities.MDM4 is a vital regulator of the tumor suppressor p53?It restricts p53 transcriptional activity and also,at least in development,facilitates MDM2's E3 ligase activity toward p53.These functions of MDM4 are critical for normal cell function and a proper response to stress.Their importance for proper cell maintenance and proliferation identifies them as a risk for deregulation associated with the uncontrolled growth of cancer.MDM4 tails are vital for its function,where its N-terminus transactivation domain engages p53 and its C-terminus RING domain binds to MDM2.In this review,we highlight recently identified cellular functions of MDM4 and survey emerging therapies directed to correcting its dys regulation in disease.展开更多
[目的]探讨化疗药物诱导肝癌细胞凋亡的潜在机制。[方法]高通量测序检测顺铂处理后肝癌细胞HepG2的失调miRNA。过表达失调miRNA后,检测HepG2的凋亡水平。miRDB在线分析和RNAi筛选鉴定miRNA的潜在底物。[结果]顺铂处理后,HepG2的凋亡水...[目的]探讨化疗药物诱导肝癌细胞凋亡的潜在机制。[方法]高通量测序检测顺铂处理后肝癌细胞HepG2的失调miRNA。过表达失调miRNA后,检测HepG2的凋亡水平。miRDB在线分析和RNAi筛选鉴定miRNA的潜在底物。[结果]顺铂处理后,HepG2的凋亡水平上升(18.23±3.01 vs 74.97±11.25,t=8.564,P<0.05)。过表达miR-301a-3p时,HepG2的凋亡水平上升(16.40±7.97 vs 56.12±9.37,t=5.590,P<0.05)。敲低miR-301a-3p时,HepG2的凋亡水平下降(21.34±3.34 vs 6.78±1.11,t=7.165,P<0.05)。敲低MDM4时,HepG2的凋亡水平上升(16.80±7.88 vs 72.85±10.70,t=7.302,P<0.05)。过表达MDM4时,HepG2的凋亡水平下降(19.11±5.02 vs 6.04±1.02,t=4.432,P<0.05)。过表达miR-301a-3p时,MDM4的mRNA水平和蛋白水平均下降(0.58±0.04 vs 0.11±0.01,t=19.74,P<0.05);而敲低miR-301a-3p时,MDM4的mRNA水平和蛋白水平均上升(0.58±0.04 vs 1.11±0.23,t=3.932,P<0.05)。肝癌组织中miR-301a-3p的表达水平显著低于癌旁组织(0.65±0.25 vs 0.40±0.04,t=5.949,P<0.05)。肝癌组织中MDM4的表达水平显著高于癌旁组织(0.036±0.025 vs 0.062±0.003,t=6.550,P<0.05)。同时,肝癌组织中miR-301a-3p和MDM4的表达水平呈现负相关(ρ=-0.385,P<0.05)。[结论]顺铂诱导肝癌细胞miR-301a-3p表达上调,miR-301a-3p通过靶向MDM4 mRNA的3’端非编码区,降解了MDM4 mRNA,减少了MDM4的蛋白表达,最终促进了肝癌细胞的凋亡。展开更多
Mouse double minute （Mdm） genes span an evolutionary timeframe from the ancient eukaryotic placozoa Trichoplox adhaerens to Homo sapiens, implying a significant and possibly conserved cellular role throughout histor...Mouse double minute （Mdm） genes span an evolutionary timeframe from the ancient eukaryotic placozoa Trichoplox adhaerens to Homo sapiens, implying a significant and possibly conserved cellular role throughout history. Maintenance of DNA integrity and response to DNA damage involve many key regulatory pathways, including precise control over the tumour suppressor pro- tein p53. In most vertebrates, degradation of p53 through proteasomal targeting is primarily mediated by heterodimers of Mdm2 and the Mdm2-related protein Mdm4 （also known as MdmX）. Both Mdm2 and Mdm4 have p53-binding regions, acidic domains, zinc fingers, and C-terminal RING domains that are conserved throughout evolution. Vertebrates typically have both Mdm2 and Mdm# genes, while analyses of sequenced genomes of invertebrate species have identified single Mdm genes, suggesting that a duplication event occurred prior to emergence of jawless vertebrates about 550-440 million years ago. The functional relationship between Mdm and p53 in T. adhaerens, an organism that has existed for 1 billion years, implies that these two proteins have evolved together to maintain a conserved and regulated function.展开更多
The major cause of death from breast cancer is not the primary turnout, but relapsing, drug-resistant, metastatic disease. Identifying factors that contribute to aggressive cancer offers important leads for therapy. I...The major cause of death from breast cancer is not the primary turnout, but relapsing, drug-resistant, metastatic disease. Identifying factors that contribute to aggressive cancer offers important leads for therapy. Inherent defence against carcinogens depends on the individual molecular make-up of each person. Important molecular determinants of these responses are under the control of the mouse double minute （MDM） family： comprised of the proteins MDM2 and MDM4. In normal, healthy adult cells, the MDM family functions to critically regulate measured, cellular responses to stress and subsequent recovery. Proper function of the MDM family is vital for normal breast development, but also for preserving genomic fidelity. The MDM family members are best characterized for their negative regulation of the major tumour suppressor p53 to modulate stress responses. Their impact on other cellular regulators is emerging. Inappropriately elevated protein levels of the MDM family are highly associated with an increased risk of cancer incidence. Exploration of the MDM family members as cancer therapeutic targets is relerant for designing tailored anti-cancer treatments, but successful approaches must strategically consider the impact on both the target cancer and adjacent healthy ceils and tissues. This review focuses on recent findings pertaining to the role of the MDM family in normal and malignant breast cells.展开更多
p53 is a transcription factor that governs numerous stress response pathways within the ceil. Maintaining the right levels of p53 is crucial for ceil survival and proper cellular homeostasis, The tight regulation of p...p53 is a transcription factor that governs numerous stress response pathways within the ceil. Maintaining the right levels of p53 is crucial for ceil survival and proper cellular homeostasis, The tight regulation of p53 involves many cellular components, most notably its major negative regulators Mdm2 and Mdm4, which maintain p53 protein amount and activity in tight check, microRNAs （miRNAs） are small non-coding RNAs that target specific mRNAs to translational arrest and degradation, miRNAs are also key compo- nents of the normal p53 pathway, joining forces with Mdm2 and Mdm4 to maintain proper p53 activity. Here we review the current knowledge of miRNAs targeting Mdm2 and Mdm4, and their importance in different tissues and in pathological states such as cancer. In addition, we address the role of Alu sequences-highly abundant retroelements spread throughout the human genome, and their impact on gene regulation via the miRNA machinery. Aius occupy a significant portion of genes＇ 31UTR, and as such they have the potential to impact mRNA regulation. Since Alus are primate-specific, they introduce a new regulatory layer into primate genomes. Atus can influence and alter gene regulation, creating primate-specific cancer-preventive regulatory mechanisms to sustain the transition to longer life span in primates. We review the possible influence of Alu sequences on miRNA functionality in general and specifically within the p53 network.展开更多
Whilst most bioorthogonal reactions focus on targeting binding-site cysteine residues,proximity-induced reactivity effect ensures that reaction also occurs at nucleophilic lysine residues.We report one example here th...Whilst most bioorthogonal reactions focus on targeting binding-site cysteine residues,proximity-induced reactivity effect ensures that reaction also occurs at nucleophilic lysine residues.We report one example here that the propargylated-sulfonium center undergoes a nucleophilic reaction with lysine residue via proximity-induced conjugation.This propargylated-sulfonium tethered peptide resulting from a facile propargylation of thiolethers,enables amino-yne reaction at the selected lysine on MDM4 protein.This strategy represents a viable approach of lysine-targeted covalent inhibition in proximity.展开更多
文摘本研究旨在探讨慢性淋巴细胞白血病(CLL)患者鼠双微体4(MDM4)基因mRNA的表达情况及其在CLL预后中的意义。采用SYBR Green I荧光染料行实时定量逆转录PCR(qRT-PCR)方法检测66例CLL患者白血病细胞MDM4 mRNA的表达,以β-actin为内参照物,以2(-△Ct)方法计算MDM4的相对定量值,组间分析采用秩和检验。结果显示,66例CLL患者MDM4 mRNA相对表达水平的中位数为0.037098(0.088245-0.014875);具有P53基因缺失的CLL患者,其MDM4的表达明显高于无P53基因缺失的患者(0.13167 vs 0.030927)(p<0.001),具有P53基因突变的CLL患者MDM4 mRNA表达也明显高于无P53基因突变的患者(0.13167 vs0.03077)(p<0.001);此外,MDM4 mRNA的表达水平还与Binet分期(p=0.044)和ATM基因缺失(p=0.046)显著相关,但与血清乳酸脱氢酶(LDH)(p=0.216)、β2-微球蛋白(β2-MG)(p=0.314)、胸苷激酶(TK)1(p=0.300)、ZAP-70(p=0.559)、CD38(p=0.513)和免疫球蛋白重链可变区(IgVH)基因突变状态(p=0.333)无显著相关性。结论:MDM4的表达与P53基因异常关系密切,与Binet分期和ATM基因缺失相关,MDM4可能在CLL的预后中具有重要价值。
文摘0 引言
Shvarts et al[1]报告了一种与p53蛋白结合蛋白的新基因,命名为MDMX,与MDM2蛋白在一级结构上具有同源性,特别是在p53蛋白结合域更是如此.另外,MDM2羧基末端的金属结合域在MDMX分子中也是高度保守的.MDMX蛋白又称为MDM4,是p53的一种结合蛋白,是p53蛋白的负调节因子.
文摘Mdm2 and Mdm4 are two key negative regulators of the tumor suppressor p53.Deletion of either Mdm2 or Mdm4 induces p53-dependent early embryonic lethality in knockout mouse models.The tissuespecific deletion of Mdm2 induces p53-dependent apoptosis,whereas the deletion of Mdm4 induces both p53-dependent apoptosis and cell cycle arrest.Compared to Mdm4 deletion,Mdm2 deletion causes more severe phenotypic defects.Disrupting the Mdm2 and Mdm4 interaction using knockin mice models causes embryonic lethality that can be completely rescued by the concomitant loss of p53,suggesting that Mdm2 and Mdm4 heterodimerization is critical to inhibit p53 activity during embryogenesis.Overexpression of Mdm2 and Mdm4 in mice induces spontaneous tumorigenesis,which clearly indicates that Mdm2 and Mdm4 are bona fide oncogenes.Studies from these mouse models strongly suggest that blocking Mdm2and Mdm4-mediated p53 inhibition is an appealing therapeutic strategy for cancer patients with wild-type p53 alleles.
文摘The mouse double minute 4(MDM4)is emerging from the shadow of its more famous relative MDM2 and is starting to steal the limelight,largely due to its therapeutic possibilities.MDM4 is a vital regulator of the tumor suppressor p53?It restricts p53 transcriptional activity and also,at least in development,facilitates MDM2's E3 ligase activity toward p53.These functions of MDM4 are critical for normal cell function and a proper response to stress.Their importance for proper cell maintenance and proliferation identifies them as a risk for deregulation associated with the uncontrolled growth of cancer.MDM4 tails are vital for its function,where its N-terminus transactivation domain engages p53 and its C-terminus RING domain binds to MDM2.In this review,we highlight recently identified cellular functions of MDM4 and survey emerging therapies directed to correcting its dys regulation in disease.
文摘[目的]探讨化疗药物诱导肝癌细胞凋亡的潜在机制。[方法]高通量测序检测顺铂处理后肝癌细胞HepG2的失调miRNA。过表达失调miRNA后,检测HepG2的凋亡水平。miRDB在线分析和RNAi筛选鉴定miRNA的潜在底物。[结果]顺铂处理后,HepG2的凋亡水平上升(18.23±3.01 vs 74.97±11.25,t=8.564,P<0.05)。过表达miR-301a-3p时,HepG2的凋亡水平上升(16.40±7.97 vs 56.12±9.37,t=5.590,P<0.05)。敲低miR-301a-3p时,HepG2的凋亡水平下降(21.34±3.34 vs 6.78±1.11,t=7.165,P<0.05)。敲低MDM4时,HepG2的凋亡水平上升(16.80±7.88 vs 72.85±10.70,t=7.302,P<0.05)。过表达MDM4时,HepG2的凋亡水平下降(19.11±5.02 vs 6.04±1.02,t=4.432,P<0.05)。过表达miR-301a-3p时,MDM4的mRNA水平和蛋白水平均下降(0.58±0.04 vs 0.11±0.01,t=19.74,P<0.05);而敲低miR-301a-3p时,MDM4的mRNA水平和蛋白水平均上升(0.58±0.04 vs 1.11±0.23,t=3.932,P<0.05)。肝癌组织中miR-301a-3p的表达水平显著低于癌旁组织(0.65±0.25 vs 0.40±0.04,t=5.949,P<0.05)。肝癌组织中MDM4的表达水平显著高于癌旁组织(0.036±0.025 vs 0.062±0.003,t=6.550,P<0.05)。同时,肝癌组织中miR-301a-3p和MDM4的表达水平呈现负相关(ρ=-0.385,P<0.05)。[结论]顺铂诱导肝癌细胞miR-301a-3p表达上调,miR-301a-3p通过靶向MDM4 mRNA的3’端非编码区,降解了MDM4 mRNA,减少了MDM4的蛋白表达,最终促进了肝癌细胞的凋亡。
文摘Mouse double minute （Mdm） genes span an evolutionary timeframe from the ancient eukaryotic placozoa Trichoplox adhaerens to Homo sapiens, implying a significant and possibly conserved cellular role throughout history. Maintenance of DNA integrity and response to DNA damage involve many key regulatory pathways, including precise control over the tumour suppressor pro- tein p53. In most vertebrates, degradation of p53 through proteasomal targeting is primarily mediated by heterodimers of Mdm2 and the Mdm2-related protein Mdm4 （also known as MdmX）. Both Mdm2 and Mdm4 have p53-binding regions, acidic domains, zinc fingers, and C-terminal RING domains that are conserved throughout evolution. Vertebrates typically have both Mdm2 and Mdm# genes, while analyses of sequenced genomes of invertebrate species have identified single Mdm genes, suggesting that a duplication event occurred prior to emergence of jawless vertebrates about 550-440 million years ago. The functional relationship between Mdm and p53 in T. adhaerens, an organism that has existed for 1 billion years, implies that these two proteins have evolved together to maintain a conserved and regulated function.
文摘The major cause of death from breast cancer is not the primary turnout, but relapsing, drug-resistant, metastatic disease. Identifying factors that contribute to aggressive cancer offers important leads for therapy. Inherent defence against carcinogens depends on the individual molecular make-up of each person. Important molecular determinants of these responses are under the control of the mouse double minute （MDM） family： comprised of the proteins MDM2 and MDM4. In normal, healthy adult cells, the MDM family functions to critically regulate measured, cellular responses to stress and subsequent recovery. Proper function of the MDM family is vital for normal breast development, but also for preserving genomic fidelity. The MDM family members are best characterized for their negative regulation of the major tumour suppressor p53 to modulate stress responses. Their impact on other cellular regulators is emerging. Inappropriately elevated protein levels of the MDM family are highly associated with an increased risk of cancer incidence. Exploration of the MDM family members as cancer therapeutic targets is relerant for designing tailored anti-cancer treatments, but successful approaches must strategically consider the impact on both the target cancer and adjacent healthy ceils and tissues. This review focuses on recent findings pertaining to the role of the MDM family in normal and malignant breast cells.
文摘p53 is a transcription factor that governs numerous stress response pathways within the ceil. Maintaining the right levels of p53 is crucial for ceil survival and proper cellular homeostasis, The tight regulation of p53 involves many cellular components, most notably its major negative regulators Mdm2 and Mdm4, which maintain p53 protein amount and activity in tight check, microRNAs （miRNAs） are small non-coding RNAs that target specific mRNAs to translational arrest and degradation, miRNAs are also key compo- nents of the normal p53 pathway, joining forces with Mdm2 and Mdm4 to maintain proper p53 activity. Here we review the current knowledge of miRNAs targeting Mdm2 and Mdm4, and their importance in different tissues and in pathological states such as cancer. In addition, we address the role of Alu sequences-highly abundant retroelements spread throughout the human genome, and their impact on gene regulation via the miRNA machinery. Aius occupy a significant portion of genes＇ 31UTR, and as such they have the potential to impact mRNA regulation. Since Alus are primate-specific, they introduce a new regulatory layer into primate genomes. Atus can influence and alter gene regulation, creating primate-specific cancer-preventive regulatory mechanisms to sustain the transition to longer life span in primates. We review the possible influence of Alu sequences on miRNA functionality in general and specifically within the p53 network.
基金financial support from the National Key Research and Development Program"Synthetic Biology"Key Special Project of China(No.2018YFA0902504)the Natural Science Foundation of China(Nos.21778009 and 21977010)+6 种基金the Natural Science Foundation ofGuangdongProvince(Nos.2020A1515010766,2020A1515010522,2019A1515111184 and 2019A1515110489)the Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20180507181527112,JCYJ20180508152213145,and JCYJ20170817172023838)financial support from Beijing National Laboratory of Molecular Science Open Grant(No.BNLMS20160112)Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions(No.2019SHIBS0004)supported by Proteomic Platform of Pingshan Translational Medicine CenterShenzhen Bay Laboratorythe high-performance computing platform of Peking University.
文摘Whilst most bioorthogonal reactions focus on targeting binding-site cysteine residues,proximity-induced reactivity effect ensures that reaction also occurs at nucleophilic lysine residues.We report one example here that the propargylated-sulfonium center undergoes a nucleophilic reaction with lysine residue via proximity-induced conjugation.This propargylated-sulfonium tethered peptide resulting from a facile propargylation of thiolethers,enables amino-yne reaction at the selected lysine on MDM4 protein.This strategy represents a viable approach of lysine-targeted covalent inhibition in proximity.
