Experimental identification of cancer driver alterations in the era of pan‐cancer genomics

Rapidly accumulating data from large‐scale cancer genomics studies have been generating important information about genes and their somatic alterations underlying cell transformation, cancer onset and tumor progression. However, these events are usually defined by using computational techniques, whereas the understanding of their actual functional roles and impact typically warrants validation by experimental means. Critical information has been obtained from targeted genetic perturbation (gene knockout) studies conducted in animals, yet these investigations are cost‐prohibitive and time‐consuming. In addition, the 3R principles (replacement, reduction, refinement) have been set in place to reduce animal use burden and are increasingly observed in many areas of biomedical research. Consequently, the focus has shifted to new designs of innovative cell‐based experimental models of cell immortalization and transformation in which the critical cancer driver events can be introduced by mutagenic insult and studied functionally, at the level of critical phenotypic readouts. From these efforts, primary cell‐based selective barrier‐bypass models of cell immortalization have emerged as an attractive system that allows studies of the functional relevance of acquired mutations as well as their role as candidate cancer driver events. In this review, we provide an overview of various experimental systems linking carcinogen exposure‐driven cell transformation with the study of cancer driver events. We further describe the advantages and disadvantages of the currently available cell‐based models while outlining future directions for in vitro modeling and functional testing of cancer driver events.     

腰椎间盘突出症动物模型的研究进展

近年来,腰椎间盘突出症发病率逐渐增高,由于动物模型对于阐明疾病发病机制及评估新的治疗方法具有重要作用,越来越多的学者开始研究如何建立合适的、能够更好地模拟人类腰椎间盘突出的动物模型。近期的研究多选用包括大鼠、兔、羊、猪等动物作为实验对象,通过物理或化学方式直接损伤其椎间盘或神经根,或通过限制实验动物的行为动作、改变其饲养环境以及性别年龄导致的生理因素等方式诱导其出现椎间盘退变。各种造模方法均有其特点及局限性,适用于不同情况,有必要继续完善。     

Utility of food pellets containing 1-aminobenzotriazole for longer term in vivo inhibition of cytochrome P450 in mice

1. The utility of 1-aminobenzotriazole (ABT), incorporated in food, has been investigated as an approach for longer term inhibition of cytochrome P450 (P450) enzymes in mice.

2. In rats, ABT inhibits gastric emptying, to investigate this potential limitation in mice we examined the effect of ABT administration on the oral absorption of NVS-CRF38. Two hour prior oral treatment with 100?mg/kg ABT inhibited the oral absorption of NVS-CRF38, T_max was 4?hours for ABT-treated mice compared to 0.5?hours in the control group.

3. A marked inhibition of hepatic P450 activity was observed in mice fed with ABT containing food pellets for 1?month. P450 activity, as measured by the oral clearance of antipyrine, was inhibited on day 3 (88% of control), week 2 (83% of control) and week 4 (80% of control).

4. T_max values for antipyrine were comparable between ABT-treated mice and the control group, alleviating concerns about impaired gastric function.

5. Inclusion of ABT in food provides a minimally invasive and convenient approach to achieve longer term inhibition of P450 activity in mice. This model has the potential to enable pharmacological proof-of-concept studies for research compounds which are extensively metabolised by P450 enzymes.     

Structural Response Prediction of Thin-Walled Additively Manufactured Parts Considering Orthotropy,Thickness Dependency and Scatter

Besides the design freedom offered by additive manufacturing, another asset lies within its potential to accelerate product development processes by rapid fabrication of functional prototypes. The premise to fully exploit this benefit for lightweight design is the accurate structural response prediction prior to part production. However, the peculiar material behavior, characterized by anisotropy, thickness dependency and scatter, still constitutes a major challenge. Hence, a modeling approach for finite element analysis that accounts for this inhomogeneous behavior is developed by example of laser-sintered short-fiber-reinforced polyamide 12. Orthotropic and thickness-dependent Young’s moduli and Poisson’s ratios were determined via quasi-static tensile tests. Thereof, material models were generated and implemented in a property mapping routine for finite element models. Additionally, a framework for stochastic finite element analysis was set up for the consideration of scatter in material properties. For validation, thin-walled parts on sub-component level were fabricated and tested in quasi-static three-point bending experiments. Elastic parameters showed considerable anisotropy, thickness dependency and scatter. A comparison of the predicted forces with experimentally evaluated reaction forces disclosed substantially improved accuracy when utilizing the novel inhomogeneous approach instead of conventional homogeneous approaches. Furthermore, the variability observed in the structural response of loaded parts could be reproduced by the stochastic simulations.     

中药调节肠道菌群在溃疡性结肠炎治疗中的应用概述

有研究表明,肠道微生态失衡是导致溃疡性结肠炎的一个重要因素。笔者从肠道微生态角度出发,对近年来关于中药单体、活性成分、复方及制剂调节肠道菌群、治疗溃疡性结肠炎的实验与临床研究进行总结。发现中药治疗溃疡性结肠炎疗效好,不良反应少,能有效减少病情复发;无论是单味中药及其活性成分,还是中药复方均能有效调节肠道益生菌、减少有害菌群数量,使肠道菌群恢复平衡状态,从而间接调节肠道黏膜免疫功能,促进结直肠黏膜的修复。但中药通过调节肠道菌群治疗溃疡性结肠炎的疗效目前尚缺乏循证医学证据,今后应加强相关中药药理作用研究,为中药调节肠道菌群在溃疡性结肠炎治疗中的应用提供更加有力的证据。参考文献35篇。     

基于BGP、TGF-β1的表达探究蛇床子素对去卵巢致骨质疏松大鼠的作用

目的观察蛇床子素对去卵巢致骨质疏松大鼠的影响。方法选取3月龄雌性SD大鼠30只,随机分为蛇床子素组(A组)、模型对照组(B组)、假手术组(C组),各10只。A、B 2组摘除卵巢构建去势大鼠骨质疏松模型,C组仅进行手术、不摘除卵巢。造模成功后,分别给予相应药物灌胃,连续给药12周,处死。然后测量骨密度,检测治疗后血清BGP、TGF-β1、钙指标。结果B组大鼠股骨骨密度较C组明显降低(P<0.05);经12周治疗,A组股骨骨密度较B组明显升高(P<0.05)。与C组比较,B组大鼠血清中BGP含量升高、TGF-β1降低(P<0.05);与B组比较,A组大鼠血清中BGP降低、TGF-β1含量升高(P<0.05)。与C组比较,B组大鼠血清Ca水平明显降低(P<0.05);与B组比较,A组大鼠血清Ca水平明显升高(P<0.05)。差异均有统计学意义。结论蛇床子素能够有效通过调节大鼠体内激素分泌改善去卵巢大鼠的骨代谢异常,提高骨密度,对骨质疏松症起到一定的防治作用。     

补益营卫方对衰老表皮结构蛋白K17的影响

目的:观察补益营卫方对衰老表皮结构蛋白K17的基因和蛋白水平的影响。方法:将3个月龄小鼠(年轻组)与14个月龄小鼠(老年组)表皮细胞消化分离出来,然后进行传代培养,其中14个月龄小鼠(老年组)的表皮细胞分为2组,一组用常规方法培养细胞,另一组用含2.5%的补益营卫方培养基进行培养,采用荧光定量RT-PCR法和Western Blotting法分别检测细胞K17mRNA表达和细胞K17蛋白表达。结果:与年轻组比较,老年组的K17mRNA和蛋白表达水平均升高(P<0.05);经药物干预后小鼠表皮细胞中K17mRNA和蛋白水平较老年组明显降低(P<0.05)。结论:补益营卫方可通过抑制衰老表皮结构蛋白K17的表达,起到延缓皮肤衰老作用。     

国产弹性蛋白酶浸泡法构建兔腹主动脉瘤及其随访

目的采用国产猪胰弹性蛋白酶溶液主动脉周浸泡法构建兔腹主动脉瘤(AAA)模型,并随访其长期稳定性。方法 24只新西兰兔随机分成两组,实验组(n=12)用10μL浓度为10 U/μL国产猪胰弹性蛋白酶溶液浸润主动脉近分叉处血管段30 min,对照组用10μL 0.9%氯化钠溶液浸润30 min。术前和术后5、15、40、100、150 d分别经耳缘静脉造影测量主动脉内径。术后5、15、150 d造影后每组分别处死4只兔作苏木精-伊红(HE)、弹力纤维EVG染色和免疫组化染色。结果实验组术后5 d均形成AAA,主动脉直径100 d内基本稳定,150 d时明显缩小;组织学上术后5 d血管壁严重破坏、结构紊乱,可见红细胞渗出和炎性细胞浸润,弹力纤维和平滑肌细胞明显减少甚至消失,15 d时血管结构规整,可见部分残留弹力纤维,未见炎性细胞,150 d时管腔变窄,内膜过度增生,可见大量平滑肌细胞增生和紊乱的新生弹力纤维。对照组均未见AAA形成,病理学无明显变化。结论国产猪胰弹性蛋白酶溶液浸泡法可诱导兔AAA形成,操作简单、安全、有效。该模型有自愈倾向,但100 d内基本稳定,有助于AAA机制研究。     

Natural compulsive‐like behaviour in the deer mouse (Peromyscus maniculatus bairdii) is associated with altered gut microbiota composition

Obsessive–compulsive disorder (OCD) is a psychiatric illness that significantly impacts affected patients and available treatments yield suboptimal therapeutic response. Recently, the role of the gut–brain axis (GBA) in psychiatric illness has emerged as a potential target for therapeutic exploration. However, studies concerning the role of the GBA in OCD are limited. To investigate whether a naturally occurring obsessive–compulsive‐like phenotype in a rodent model, that is large nest building in deer mice, is associated with perturbations in the gut microbiome, we investigated and characterised the gut microbiota in specific‐pathogen‐free bred and housed large (LNB) and normal (NNB) nest‐building deer mice of both sexes (n = 11 per group, including three males and eight females). Following baseline characterisation of nest‐building behaviour, a single faecal sample was collected from each animal and the gut microbiota analysed. Our results reveal the overall microbial composition of LNB animals to be distinctly different compared to controls (PERMANOVA p < .05). While no genera were found to be significantly differentially abundant after correcting for multiple comparisons, the normal phenotype showed a higher loading of Prevotella and Anaeroplasma, while the OC phenotype demonstrated a higher loading of Desulfovermiculus, Aestuariispira, Peptococcus and Holdemanella (cut‐off threshold for loading at 0.2 in either the first or second component of the PCA). These findings not only provide proof‐of‐concept for continued investigation of the GBA in OCD, but also highlight a potential underlying aetiological association between alterations in the gut microbiota and the natural development of obsessive–compulsive‐like behaviours.