西藏地区藏族人群胃癌组织中H3K27me3表达水平及其临床意义

目的 探究H3K27me3在西藏地区藏族人群胃癌组织中的表达水平及其与临床、病理特征的相关性。方法 回顾性收集2019年8月至2021年8月西藏自治区人民医院藏族胃癌患者及同期藏族非胃癌患者的临床与病理资料。采用免疫组化法检测胃癌患者手术切除的肿瘤组织、癌旁正常胃黏膜组织及非胃癌患者正常胃黏膜组织中H3K27me3表达情况,并比较不同临床与病理特征胃癌患者之间H3K27me3表达差异。结果 共入选符合纳入和排除标准的藏族胃癌患者54例,藏族非胃癌患者55例。H3K27me3定位于细胞核,阳性表达时细胞核呈棕黄色颗粒状着色。胃癌组织中H3K27me3高表达率显著高于癌旁正常胃黏膜组织[64.8%(35/54)比29.6%(16/54),P<0.001]和非胃癌患者正常胃黏膜组织[64.8%(35/54)比34.5%(19/55),P=0.002],癌旁正常胃黏膜组织中H3K27me3高表达率与非胃癌患者正常胃黏膜组织无显著差异(P=0.683)。H3K27me3表达水平在不同年龄、性别及Lauren分型、分化程度、浸润深度、肿瘤最大径、TNM分期等胃癌患者之间均无显著差异(P均&g...     

基于MRI的深度学习联合影像组学评估中线胶质瘤H3 K27状态

目的 观察基于MRI的深度学习联合影像组学评估中线胶质瘤H3 K27状态的价值。方法 回顾性收集弥漫性中线胶质瘤伴H3 K27变异(H3-DMG)患者及不伴H3 K27变异的中线胶质母细胞瘤(GBM)患者各127例,按8 ∶ 2比例将其随机分为训练集(n=204)及测试集(n=50)。基于MRI提取肿瘤U-Net神经网络视觉特征及影像组学特征,建立深度学习影像组学模型,观察其评估肿瘤H3 K27状态的价值。结果 基于训练集得出0.500为模型分类任务的安全评分划分值;以所获深度学习影像组学模型评估测试集H3-DMG和GBM H3 K27状态的中位安全评分分别为0(0,0)和0.999(0.616,1.000),前者低于后者(Z=-5.114,P＜0.001)。深度学习影像组学模型评估训练集H3 K27状态的敏感度、特异度、准确率及曲线下面积分别为93.14%、81.37%、87.25%及0.953 ,而在测试集分别为88.00%、80.00%、84.00%及0.922 。结论 基于MRI深度学习影像组学可准确评估中线胶质瘤H3 K27状态。     

The establishment of CDK9/RNA PolII/H3K4me3/DNA methylation feedback promotes HOTAIR expression by RNA elongation enhancement in cancer

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The Burkholderia pseudomallei Enoyl-Acyl Carrier Protein Reductase FabI1 Is Essential for In Vivo Growth and Is the Target of a Novel Chemotherapeutic with Efficacy

The bacterial fatty acid biosynthesis pathway is a validated target for the development of novel chemotherapeutics. However, since Burkholderia pseudomallei carries genes that encode both FabI and FabV enoyl-acyl carrier protein (ACP) reductase homologues, the enoyl-ACP reductase that is essential for in vivo growth needs to be defined so that the correct drug target can be chosen for development. Accordingly, ΔfabI1, ΔfabI2, and ΔfabV knockout strains were constructed and tested in a mouse model of infection. Mice infected with a ΔfabI1 strain did not show signs of morbidity, mortality, or dissemination after 30 days of infection compared to the wild-type and ΔfabI2 and ΔfabV mutant strains that had times to mortality of 60 to 84 h. Although signs of morbidity and mortality of ΔfabI2 and ΔfabV strains were not significantly different from those of the wild-type strain, a slight delay was observed. A FabI1-specific inhibitor was used to confirm that inhibition of FabI1 results in reduced bacterial burden and efficacy in an acute B. pseudomallei murine model of infection. This work establishes that FabI1 is required for growth of Burkholderia pseudomallei in vivo and is a potential molecular target for drug development.     

脊髓H3K27M突变型与野生型星形细胞分化弥漫性中线胶质瘤MRI特征

目的 观察脊髓H3K27M突变型与野生型星形细胞分化弥漫性中线胶质瘤(DMG)MRI特征。方法 回顾性分析91例经病理确诊脊髓星形细胞分化DMG患者,根据H3K27M状态分为突变组(n=44)和野生组(n=47);观察组间临床和MRI表现差异,采用logistic回归分析筛选H3K27M突变的影响因素。结果 突变组瘤周水肿和脊髓空洞发生率均小于野生组(P均＜0.05),其余组间差异均无统计学意义(P均＞0.05)。将所有临床及MRI参数纳入logistic回归分析,结果显示其均非H3K27M突变的影响因素(P均＞0.05)。结论 脊髓H3K27M突变型星形细胞分化DMG瘤周水肿和脊髓空洞发生率均低于野生型,但尚不足以作为预测DMG发生H3K27M突变的影响因素。     

Selective inhibition of EZH2 by ZLD10A blocks H3K27 methylation and kills mutant lymphoma cells proliferation

EZH2 (Enhancer of zeste homolog 2) is the catalytic subunit of the polycomb repressive complex 2 (PRC2), which is involved in repressing gene expression by methylating lysine 27 of histone H3 (H3K27) and regulates cell proliferation. EZH2 overexpression is implicated in tumorigenesis and has been a candidate oncogene in several tumor types. Recently, point mutations of EZH2 at Tyr641 and Ala677 were identified in diffuse large B cell lymphoma and follicular lymphoma, where they drive H3K27 hypertrimethylation and cancer progression. Here, we reported a novel, highly potent and selective small molecule inhibitor of EZH2, ZLD10A, which inhibited wild-type and mutant versions of EZH2 with nanomolar potency and had greater than 1000-fold selectivity against 10 other histone methyltransferases. Our results have shown that the compound suppressed global H3K27 methylation and cause the anti-proliferation effects in a concentration- and time-dependent manner in DLBCL cell lines. These results demonstrated that ZLD10A, as a novel EZH2 inhibitor, could be a potential promising agent for the treatment of EZH2 mutant lymphoma.     

The Lymphocyte Function–associated Antigen 1 I Domain Is a Transient Binding Module for Intercellular Adhesion Molecule (ICAM)-1 and ICAM-3 in Hydrodynamic Flow

The I domain of lymphocyte function–associated antigen (LFA)-1 contains an intercellular adhesion molecule (ICAM)-1 and ICAM-3 binding site, but the relationship of this site to regulated adhesion is unknown. To study the adhesive properties of the LFA-1 I domain, we stably expressed a GPI-anchored form of this I domain (I-GPI) on the surface of baby hamster kidney cells. I-GPI cells bound soluble ICAM-1 (sICAM-1) with a low avidity and affinity. Flow cell experiments demonstrated a specific rolling interaction of I-GPI cells on bilayers containing purified full length ICAM-1 or ICAM-3. The LFA-1 activating antibody MEM-83, or its Fab fragment, decreased the rolling velocity of I-GPI cells on ICAM-1–containing membranes. In contrast, the interaction of I-GPI cells with ICAM-3 was blocked by MEM-83. Rolling of I-GPI cells was dependent on the presence of Mg²⁺. Mn²⁺ only partially substituted for Mg²⁺, giving rise to a small fraction of rolling cells and increased rolling velocity. This suggests that the I domain acts as a transient, Mg²⁺-dependent binding module that cooperates with another Mn²⁺-stimulated site in LFA-1 to give rise to the stable interaction of intact LFA-1 with ICAM-1.     

Essential and Partially Overlapping Role of CD3γ and CD3δ for Development of αβ and γδ T Lymphocytes

CD3γ and CD3δ are two highly related components of the T cell receptor (TCR)–CD3 complex which is essential for the assembly and signal transduction of the T cell receptor on mature T cells. In gene knockout mice deficient in either CD3δ or CD3γ, early thymic development mediated by pre-TCR was either undisturbed or severely blocked, respectively, and small numbers of TCR-αβ⁺ T cells were detected in the periphery of both mice. γδ T cell development was either normal in CD3δ^−/− mice or partially blocked in CD3γ^−/− mice. To examine the collective role of CD3γ and CD3δ in the assembly and function of pre-TCR and in the development of γδ T cells, we generated a mouse strain with a disruption in both CD3γ and CD3δ genes (CD3γδ^−/−). In contrast to mice deficient in either CD3γ or CD3δ chains, early thymic development mediated by pre-TCR is completely blocked, and TCR-αβ⁺ or TCR-γδ⁺ T cells were absent in the CD3γδ^−/− mice. Taken together, these studies demonstrated that CD3γ and CD3δ play an essential, yet partially overlapping, role in the development of both αβ and γδ T cell lineages.     

组蛋白H3K27甲基化抑制剂EPZ005687对U937细胞和正常骨髓CD34^＋细胞凋亡、增殖及细胞周期的影响

本研究目的在于探讨组蛋白H3K27甲基化抑制剂新药EPZ005687对白血病细胞系U937细胞和正常骨髓CD34＋细胞的凋亡、增殖抑制和细胞周期的影响。以不同浓度的EPZ005687作用于U937细胞,在不同时间点采用Annexin V/PI法检测细胞凋亡,WST-1法检测细胞增殖,7-AAD流式细胞术检测法检测细胞周期,免疫化学法检测H3K27组蛋白甲基化活性。结果表明：EPZ005687显著诱导U937细胞的凋亡,在0.5、1、5和10μmol/L浓度下作用于U937细胞48 h后,其凋亡率分别为3.96%±0.79%、5.74%±0.73%、13.34%±1.77%和25.24%±2.55%,而EPZ005687对正常骨髓CD34＋细胞的凋亡影响较小;在0.5、1、5和10μmol/L浓度下CD34＋细胞凋亡率分别为3.64%±0.62%、4.28%±0.99%、6.18%±1.19%和7.56%±1.34%;0.5、1、5和10μmol/L浓度的EPZ005687分别作用于U937细胞12 h至96 h,作用CD34＋细胞1至5 d,明显观察到EPZ005687显著抑制U937细胞的增殖且呈剂量依赖性,而对正常CD34＋细胞的增殖抑制并不明显。细胞周期分析显示,1μmol/L EPZ005687作用72 h可使U937细胞明显阻滞于G1期（64.18%±13.27%vs 49.43%±12.54%）,S期细胞比例明显下降低（9.67%±2.61%vs 15.26%±5.58%）,而正常CD34＋细胞因多数细胞位于G1期,S期细胞较少而不受其影响。进一步的H3K27组蛋白甲基化检测分析显示,EZP005687可明显地降低U937细胞的H3K27组蛋白甲基化,而不降低正常CD34＋细胞的H3K27组蛋白甲基化。结论：组蛋白H3K27甲基化抑制剂EPZ005687明显抑制U937细胞的增殖,诱导细胞凋亡和细胞周期阻滞,但对正常造血细胞CD34＋影响较小,可作为一种潜在的血液肿瘤治疗药物应用于临床。     

Angiostatin K1‐3 induces E‐selectin via AP1 and Ets1: a mediator for anti‐angiogenic action of K1‐3

Summary. Background: Angiostatin, a circulating angiogenic inhibitor, is an internal fragment of plasminogen and consists of several isoforms, K1‐3 included. We previously showed that K1‐3 was the most potent angiostatin to induce E‐selectin mRNA expression. The purpose of this study was to identify the mechanism responsible for K1‐3‐induced E‐selectin expression and investigate the role of E‐selectin in the anti‐angiogenic action of K1‐3. Methods and results: Quantitative real time RT‐PCR and Western blotting analyses confirmed a time‐dependent increase of E‐selectin mRNA and protein induced by K1‐3. Subcellular fractionation and immunofluorescence microscopy showed the co‐localization of K1‐3‐induced E‐selectin with caveolin 1 (Cav1) in lipid rafts in which E‐selectin may behave as a signaling receptor. Promoter‐driven reporter assays and site‐directed mutagenesis showed that K1‐3 induced E‐selectin expression via promoter activation and AP1 and Ets‐1 binding sites in the proximal E‐selectin promoter were required for E‐selectin induction. The in vivo binding of both protein complexes to the proximal promoter was confirmed by chromatin immunoprecipitation (ChIP). Although K1‐3 induced the activation of ERK1/2 and JNK, only repression of JNK activation attenuated the induction of E‐selectin by K1‐3. A modulatory role of E‐selectin in the anti‐angiogenic action of K1‐3 was manifested by both overexpression and knockdown of E‐selectin followed by cell proliferation assay. Conclusions: We show that K1‐3 induced E‐selectin expression via AP1 and Ets‐1 binding to the proximal E‐selectin promoter (?356/+1), which was positively mediated by JNK activation. Our findings also demonstrate E‐selectin as a novel target for the anti‐angiogenic therapy.     

甲型H1N1流感流行期间非隔离病房综合消毒防护措施的探讨

目的通过制定一整套综合消毒防护措施来降低甲型H1N1流感流行期间非隔离病房院内呼吸道传染性疾病的发生率。方法以消化一科为对照病房(B组),消化二科作为综合消毒防护示范病房(A组),采取以下措施:实行科学宣教,制定新的家属探视及陪护制度,加强病房通风及消毒规范。结果对甲型H1N1流感防控知识的知晓率明显提高;探视人数明显减少;综合示范病房的空气菌落数明显减少;院内感染包括上呼吸道感染的发生率降低;无甲型H1N1流感病例出现(P0.05)。结论在甲型H1N1流感暴发和流行期间,严格、综合的消毒防护措施是非常重要的,可以提高病人及家属对甲型H1N1流感的认知能力,减少院内感染发生率。     

脑膜瘤患者IGF-1、IGFBP-3测定的意义

目的：探索人脑膜瘤患者IGF-1、IGFBP-3与脑膜瘤发生发展的关系,为提高脑膜瘤的早期诊断率提供实验依据。方法正常对照组、脑膜瘤组各30例,血清标本均用免疫放射分析法测定IGF-1、IGFBP-3浓度。术中分别取两组的组织标本,行常规HE切片染色及IGF-1免疫组化染色,观察免疫组化染色结果。结果脑膜瘤组血清IGF-1水平明显升高,与对照组比较差异有统计学意义（P＜0.05）。脑膜瘤组血清IGFBP-3水平也明显升高（P＜0.05）。二组血清IGF-1水平均与血清IGFBP-3水平呈正相关（r=0.594、0.474,P＜0.05）。正常脑组织中IGF-1无表达;脑膜瘤组织中的IGF-1表达水平也升高（P＜0.05）。结论IGF-1可能促进了脑膜瘤的发生发展。IGFBP-3可能协同IGF-1促进了脑膜瘤的发生发展。     

Binding of [3H]3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid to rat brain membranes: a selective, high-affinity ligand for N-methyl-D-aspartate receptors

3-(2-Carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP), a rigid analog of 2-amino-7-phosphonoheptanoic acid, has been reported as a selective N-methyl-D-aspartate (NMDA) antagonist. [3H]CPP bound with relatively high affinity (Kd = 201 nM) to Triton-treated rat brain crude synaptic membranes using a centrifugation assay. Binding was saturable, reversible, heat sensitive and dependent on protein concentration. Specific binding, which represented 75 to 85% of the total counts bound, was enriched in synaptosomal and microsomal fractions of rat brain, suggesting an involvement in events related to synaptic transmission. On a regional basis, binding was highest in hippocampus, followed by cortex greater than striatum greater than cerebellum = thalamus. No specific binding could be detected in pons medulla or in liver, kidney, heart, lung and adrenal tissue. [3H]CPP binding was stereoselective for the isomers of glutamate, 2-amino-5-phosphonopentanoic acid, homocysteic acid, alpha-aminoadipic acid and N-methyl-aspartate. The most potent compounds tested were L-glutamate and CPP, which were equiactive in displacing [3H]CPP. The order of activity of other excitatory amino acid receptor ligands was D-2-amino-5-phosphonopentanoic acid greater than L-homocysteic acid greater than or equal to DL-2-amino-7-phosphonoheptanoic acid = D-aspartate = L-aspartate greater than L-serine-O-sulfate = D-alpha-aminoadipic acid = ibotenate greater than NMDA greater than DL-2-amino-6-phosphonohexanoic acid greater than quisqualate greater than N-methyl-L-aspartate. The quisqualate- and kainate-type receptor agonists DL-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate and kainic acid, respectively, had negligible activity at 100 microM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evolution of Oseltamivir Resistance Mutations in Influenza A(H1N1) and A(H3N2) Viruses during Selection in Experimentally Infected Mice

The evolution of oseltamivir resistance mutations during selection through serial passages in animals is still poorly described. Herein, we assessed the evolution of neuraminidase (NA) and hemagglutinin (HA) genes of influenza A/WSN/33 (H1N1) and A/Victoria/3/75 (H3N2) viruses recovered from the lungs of experimentally infected BALB/c mice receiving suboptimal doses (0.05 and 1 mg/kg of body weight/day) of oseltamivir over two generations. The traditional phenotypic and genotypic methods as well as deep-sequencing analysis were used to characterize the potential selection of mutations and population dynamics of oseltamivir-resistant variants. No oseltamivir-resistant NA or HA changes were detected in the recovered A/WSN/33 viruses. However, we observed a positive selection of the I222T NA substitution in the recovered A/Victoria/3/75 viruses, with a frequency increasing over time and with an oseltamivir concentration from 4% in the initial pretherapy inoculum up to 28% after two lung passages. Although the presence of mixed I222T viral populations in mouse lungs only led to a minimal increase in oseltamivir 50% enzyme-inhibitory concentrations (IC₅₀s) (by a mean of 5.7-fold) compared to that of the baseline virus, the expressed recombinant A/Victoria/3/75 I222T NA protein displayed a 16-fold increase in the oseltamivir IC₅₀ level compared to that of the recombinant wild type (WT). In conclusion, the combination of serial in vivo passages under neuraminidase inhibitor (NAI) pressure and temporal deep-sequencing analysis enabled, for the first time, the identification and selection of the oseltamivir-resistant I222T NA mutation in an influenza H3N2 virus. Additional in vivo selection experiments with other antivirals and drug combinations might provide important information on the evolution of antiviral resistance in influenza viruses.     

Lyn,Jak2, and Raf-1 Kinases Are Critical for the Antiapoptotic Effect of Interleukin 5, whereas only Raf-1 Kinase Is Essential for Eosinophil Activation and Degranulation

Interleukin (IL)-5 has been shown to activate many signaling molecules in eosinophils, but their functional relevance remains unknown. We have examined the functional relevance of Lyn, Jak2, and Raf-1 kinases in eosinophil survival, upregulation of adhesion molecules and degranulation. To this goal we used Lyn and Raf-1 antisense (AS) oligodeoxynucleotides (ODN) to inhibit the expression of these proteins and tyrphostin AG490 to specifically block the activation of Jak2. We have demonstrated that all three kinases are important for IL-5– induced suppression of eosinophil apoptosis. However, Lyn and Jak2 tyrosine kinases are not important for the upregulation of CD11b and the secretion of eosinophil cationic protein. In contrast, Raf-1 kinase is critical for both these functions. This is the first identification of specific signaling molecules responsible for three important functions of eosinophils. We have established a central role for Raf-1 kinase in regulating eosinophil survival, expression of β₂ integrins and degranulation. Further, there appears to be a dissociation between two receptor-associated tyrosine kinases, i.e., Lyn and Jak2, and the activation of Raf-1 kinase. The delineation of the functional relevance of signaling molecules will help design therapeutic approaches targeting specific eosinophil function.     

Efficacy of histamine H1 and H2 receptor blockers in the anesthetic management during operation for hydatid cysts of liver and lungs

We studied the effects of preoperative administration of histamine (H1 and H2) receptor blockers on hemodynamic changes in two groups of patients having operation for hydatid cyst. Patients in group 1 received no antihistaminics, whereas those in group 2 were pretreated with both H1 (diphenhydramine) and H2 (cimetidine) receptor blockers. Even though there were significant hemodynamic responses associated with spillage of hydatid cyst contents in both groups, the hemodynamic changes were significantly less in the patients who had received histamine receptor blockers. We conclude that the preoperative administration of H1 and H2 receptor blockers to patients having hydatid cyst surgery is beneficial.     

Susceptibilities to rimantadine of influenza A/H1N1 and A/H3N2 viruses isolated during the epidemics of 1988 to 1989 and 1989 to 1990.

Clinical isolates of influenza A viruses identified during outbreaks in two winters were tested for their rimantadine susceptibilities by an enzyme-linked immunosorbent assay modified from that described previously by Belshe et al. (R. B. Belshe, B. Burk, F. Newman, R. L. Cerruti, and I. S. Sim, J. Virol. 62:1508-1512, 1988). The infectivity titer and the 50% inhibitory concentration of rimantadine were calculated for each virus. Of 105 influenza virus A isolates tested, 28 influenza A/H1N1 isolates from the 1988 and 1989 outbreak and 77 influenza A/H3N2 isolates from the outbreak in following year, were susceptible to the antiviral action of rimantadine.