Combination of diethyldithiocarbamate with 12-O-tetradecanoyl phorbol-13-acetate inhibits the growth of human myeloid leukemia HL-60 cells in vitro and in xenograft model

ABSTRACT

12-O-tetradecanoylphorbol-13-acetate (TPA), is a major active constituent of the seed oil of Croton tiglium L., has pharmacological activity for the treatment of acute myeloid leukemia patients. Diethyldithiocarbamate (DTC) is a potent inhibitor of NF-κB show activity of anticancer. In this study, we determined the effect of DTC and TPA in combination on HL-60 cells cultured in vitro and in vivo. In this study, we have shown that DTC and TPA synergistically inhibited the growth of HL-60 cells and strongly induced apoptosis in the cells. Mechanistic studies showed that the combined effects of DTC and TPA were associated with a decrease in Bcl-2. The animal experiment showed that the combination of DTC and TPA more potently inhibited the growth of HL-60 tumors than either agent alone. Our results indicate that the administration of TPA and DTC in combination may be an effective strategy for inhibiting the growth of acute myeloid leukemia cells.     

Eukaryotic translation initiation factor 3 subunit b is a novel oncogenic factor in prostate cancer

Mammalian Genome - Prostate cancer, the second most common cancer among male adults, affects millions globally. We sought to investigate the expression and contribution of Eukaryotic translation...     

Requirements for human embryonic stem cells

‘Requirements for Human Embryonic Stem Cells’ is the first set of guidelines on human embryonic stem cells in China, jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research. This standard specifies the technical requirements, test methods, test regulations, instructions for use, labelling requirements, packaging requirements, storage requirements and transportation requirements for human embryonic stem cells, which is applicable to the quality control for human embryonic stem cells. It was originally released by the China Society for Cell Biology on 26 February 2019 and was further revised on 30 April 2020. We hope that publication of these guidelines will promote institutional establishment, acceptance and execution of proper protocols, and accelerate the international standardization of human embryonic stem cells for applications.     

The mechanism of Single strand binding protein–RecG binding: Implications for SSB interactome function

The Escherichia coli single‐strand DNA binding protein (SSB) is essential to viability where it functions to regulate SSB interactome function. Here it binds to single‐stranded DNA and to target proteins that comprise the interactome. The region of SSB that links these two essential protein functions is the intrinsically disordered linker. Key to linker function is the presence of three, conserved PXXP motifs that mediate binding to oligosaccharide‐oligonucleotide binding folds (OB‐fold) present in SSB and its interactome partners. Not surprisingly, partner OB‐fold deletions eliminate SSB binding. Furthermore, single point mutations in either the PXXP motifs or, in the RecG OB‐fold, obliterate SSB binding. The data also demonstrate that, and in contrast to the view currently held in the field, the C‐terminal acidic tip of SSB is not required for interactome partner binding. Instead, we propose the tip has two roles. First, and consistent with the proposal of Dixon, to regulate the structure of the C‐terminal domain in a biologically active conformation that prevents linkers from binding to SSB OB‐folds until this interaction is required. Second, as a secondary binding domain. Finally, as OB‐folds are present in SSB and many of its partners, we present the SSB interactome as the first family of OB‐fold genome guardians identified in prokaryotes.     

重组枯草芽孢杆菌全细胞催化合成2-O-α-D-甘油葡糖苷

2-O-α-D-甘油葡糖苷是一种在食品、化妆品、保健品及医药领域有着重大应用前景的高附加值产品,但国内仍未实现2-O-α-D-甘油葡糖苷的工业化生产,且鲜有关于2-O-α-D-甘油葡糖苷合成的相关报道。文中旨在开发一种利用食品安全级重组枯草芽孢杆菌全细胞催化合成2-O-α-D-甘油葡糖苷的方法,通过构建一株异源表达肠膜明串珠菌蔗糖磷酸化酶 (Sucrose phosphorylase,SPase) 的重组枯草芽孢杆菌Bacillus subtilis 168/pMA5-gtfA,并将其用作全细胞催化剂合成2-O-α-D-甘油葡糖苷,通过优化培养温度、时间及全细胞转化条件,提高其转化合成2-O-α-D-甘油葡糖苷的产量。结果表明,重组枯草芽孢杆菌B. subtilis 168/pMA5-gtfA在30 ℃下培养20 h,菌体裂解物酶活力最大达1.43 U/mL,并且在1 mol/L蔗糖、2.5 mol/L甘油、pH 7.0、菌体OD600为40、30 ℃下全细胞转化反应48 h,共生成2-O-α-D-甘油葡糖苷189.3 g/L,平均转化速率为15.6 mmol/(L·h),蔗糖转化率约为75.1%,是目前报道的利用重组枯草芽孢杆菌催化合成2-O-α-D-甘油葡糖苷的最高产量,这为2-O-α-D-甘油葡糖苷的工业化生产及应用奠定了理论和实验基础。     

大鼠脑缺血/再灌注过程中血流量和脑组织含水量的变化趋势*

目的:研究大鼠脑缺血/再灌注过程中血流量及与脑组织水含量变化的趋势。方法:选取5只成年SD雄性大鼠(n=5),参照改良Zea-Longa线栓法制备大鼠大脑中动脉缺血/再灌注模型,2 h后拔出线栓。利用PeriCam PSI血流灌注成像系统实时监测大鼠在缺血前及缺血5 min、30 min、1 h、2 h、再灌注5 min、30 min、1 h、2 h、4 h、6 h及24 h的血流灌注量,记录在ROI(感兴趣区)测量的数值。再选取15只成年SD雄性大鼠,分为Control组、缺血2 h、再灌注30 min、4 h及24 h组(n=3)。正常组不做任何处理,实验组按上述线栓法制备MCAO模型。取新鲜脑组织用干湿重法测定其左、右半球的水含量。结果:栓塞时缺血侧血流量逐渐下降,缺血2 h下降最低(P＜0.05);再灌注早期血流量恢复较大(P＜0.05),30 min时显著下降(P＜0.05),4 h明显上升(P＜0.05),24 h再次上升(P＜0.05)但低于缺血前血流量(P＞0.05)。脑组织水含量测量,缺血2 h组和再灌注30 min组与正常组无明显差异(P＞0.05);再灌4 h组和再灌24 h组明显增高(P＜0.05),且再灌24 h组明显高于再灌4 h组(P＜0.05)。结论:大鼠脑缺血/再灌注过程中血流量和脑组织中水含量的变化存在一定的规律,且脑组织中水含量与再灌注过程中血流量的变化有一定关系。     

生物多样性与传染性疾病的关系: 进展、挑战与展望

在全球生物多样性快速丧失的背景下, 理解生物多样性如何影响传染性疾病风险具有重要意义。大量研究表明, 宿主多样性对传染性疾病可能存在稀释效应(即疾病风险随宿主生物多样性的增加而降低), 但是也有放大效应或者没有影响的证据。本文首先介绍了关于生物多样性与传染性疾病关系的研究进展, 以及该领域的热点研究问题, 包括宿主多样性-疾病关系的格局和空间依赖性、稀释效应的体系依赖性和系统发育稀释效应等。随后,介绍了相关研究伴随的争议和批判, 主要集中在: 稀释效应发生的普遍性、生物多样性-疾病关系实验研究的发表偏好性以及部分疾病生态学家对生物多样性和传染性疾病之间简单数字关系的过分关注。最后指出稀释效应与物种共存、全球变化对稀释效应的影响、进化与稀释效应、稀释效应在政策制定中的应用等领域可能是今后的主要研究方向。     

气候变化和经济发展对肾综合征出血热发生的影响

肾综合征出血热(hemorrhagic fever with renal syndrome, HFRS)是一种啮齿动物传播的自然疫源性疾病, 危害严重, 已成为全球重要的公共卫生问题。本研究采用数理统计模型及小波分析方法, 对陕西省西安市鄠邑区1984-2016年HFRS的发生与鼠类、气候和经济因素的关系进行分析, 探讨气候和经济因素对HFRS发生的影响。小波分析结果表明, 该地区的HFRS暴发史可能分为两个时期, 推测每个时期具有不同的主要宿主, 在2002年褐家鼠(Rattus norvegicus)可能取代黑线姬鼠(Apodemus agrarius)成为HFRS疫源地的主要宿主。广义可加模型模拟结果表明, HFRS的发生与1984-2001年黑线姬鼠密度间存在极显著非线性效应(F_2.06,9.02 = 102.415, P < 0.01), 两者间显现为正相关; 与2002-2016年的褐家鼠密度间呈正相关(F_1.67,9.02 = 73.929, P < 0.01); HFRS主要宿主的这种变化可能与当地气候变化和经济发展有关: HFRS的发生与年平均温度存在极显著的非线性效应(F_2.93,9.02 = 12.164, P < 0.01), 两者间呈负相关; 同样, HFRS的发生与上一年的国内生产总值(GDP)也存在显著非线性效应(F_1.70,9.02 = 2.917, P < 0.05), 两者间也呈负相关。结构方程模型通过直接和间接的影响途径证明了这种转移机制, 发现温度对HFRS发生有显著的直接负向影响以及通过褐家鼠的间接正向影响; GDP对HFRS发生有直接的负向影响。本研究表明HFRS的发生与气候变化和经济发展相关, 两者均能影响HFRS的暴发, 该结论有助于今后更好地对HFRS疾病进行预防和控制。     

四川省蝶类物种组成及名录

通过整理鉴定四川大学自然博物馆馆藏的100多年间采自四川省的1万余号蝶类标本,最早的四川蝶类标本(宽带凤蝶西部亚种Papilio nephelus chaon)采于1910年,结合文献和专著资料,参考《中国蝶类志》的分类系统,得到四川省蝶类644种,隶属于12科240属。其中,蛱蝶科Nymphalidae 162种、弄蝶科Hesperiidae 125种、眼蝶科Satyridae 114种、灰蝶科Lycaenidae 100种、粉蝶科Pieridae 59种、凤蝶科Papilionidae 45种、蚬蝶科Riodinidae 14种、绢蝶科Parnassiidae 11种、斑蝶科Danaidae 8种、环蝶科Amathusiidae 4种、喙蝶科Libytheidae 1种、珍蝶科Acraeidae 1种。四川省蝶类物种组成丰富,其中,蛱蝶科、弄蝶科、眼蝶科和灰蝶科物种数均超过或达到100种。建议在全省范围内选择不同生境建立长期监测点,持续监测蝶类物种多样性分布及变化情况,这对于保护全省生态环境和维持生物多样性都是至关重要的。建议尽快开展相关研究,包括四川省蝶类的经典分类学、系统发育及区系、生物地理学、生态学、行为学和进化生态学等研究。