三维细胞培养技术应用于肿瘤细胞的研究进展

三维细胞培养是一种模拟细胞在体内微环境生长的新兴培养技术。在三维支架中细胞能以三维空间的方式生长,并以三维方式与周围的微环境交互作用,能充分体现肿瘤细胞的黏附、侵袭及远端转移过程,可作为动物模型和二维培养模型之间的桥梁。三维细胞培养技术广泛应用于肿瘤模型构建、肿瘤细胞生理学研究以及肿瘤耐药机制分析等的研究。     

通过模拟胚胎微环境逆转肿瘤的研究进展

肿瘤的发生和发展源于一小部分具有自我更新能力的肿瘤干细胞。胚胎干细胞也具有自我更新和多向分化的特性。胚胎干细胞特异的基质微环境能够提供干细胞正常生长的调控分子,在细胞不断更新的情况下,使增殖和分化达到平衡。受胚胎干细胞调节的基质或胚胎微环境作用于肿瘤细胞,可以使肿瘤细胞获得更多的分化表型,显著降低其恶性程度,抑制肿瘤细胞的侵袭行为。进一步的分子机制研究发现,在肿瘤细胞中高表达的Nodal蛋白会抑制肿瘤细胞分化,而胚胎干细胞分泌的糖基化Lefty蛋白可以负反馈调节Nodal蛋白的作用,从而降低肿瘤细胞的恶性程度。利用组织工程来模拟胚胎干细胞微环境,保留Lefty蛋白,从而逆转肿瘤的方法具有广阔的前景。     

炎症反应促进肿瘤的侵袭和转移的研究进展

恶性肿瘤严重威胁人类健康,其侵袭和转移是肿瘤患者死亡的重要原因。大量研究表明,肿瘤微环境对肿瘤细胞的侵袭和转移有着重要的作用。肿瘤细胞在肿瘤微环境中会受到多种因素的影响,其中炎症反应产生的多种炎症细胞、细胞因子等会为肿瘤细胞的恶性转化提供有利条件。     

癌相关成纤维细胞的特性及其调控肿瘤进程的研究进展

肿瘤组织是由恶性上皮细胞及其周围的基质细胞微环境形成的复杂混合体。在肿瘤的发生发展过程中,肿瘤细胞与肿瘤微环境相互作用相互影响,其中癌相关成纤维细胞(CAF)是肿瘤微环境的重要组成部分。CAF不仅促进肿瘤细胞的增殖与转移、肿瘤微血管生成以及耐药性产生,还能抑制机体的抗肿瘤免疫,从而促进肿瘤的恶性进展。本文简要综述癌相关成纤维细胞的特性及其在调控肿瘤发生发展中的作用。     

血液系统恶性疾病中巨噬细胞的研究进展

巨噬细胞是微环境中重要成员,其表型、功能具有很强的异质性;近年的研究不仅揭示了稳态条件下不同亚群的形态、表型及功能特点,而且逐步阐明疾病状态下巨噬细胞的变化及作用机制.肿瘤微环境中的巨噬细胞称为肿瘤相关巨噬细胞(T A M s),参与肿瘤增殖、血管生成、浸润、转移及化疗抵抗.在血液系统恶性疾病中,巨噬细胞广泛浸润到淋巴瘤、骨髓瘤、白血病等恶性细胞累及的组织中,被恶性微环境异常活化,获得了特异的活化表型,并参与疾病进展.在淋巴瘤、骨髓瘤中习惯沿用T A M s的名称;在白血病中其名称引申为白血病相关巨噬细胞、急性白血病相关巨噬细胞或者"保姆样细胞".本文综述了血液系统恶性疾病中巨噬细胞的研究进展.     

肿瘤微环境代谢对T细胞的影响

肿瘤微环境(tumor microenvironment,TME)包含肿瘤组织中各种细胞如肿瘤细胞、免疫细胞、成纤维细胞等,还包含这些细胞分泌的各种可溶性因子,以及代谢底物(如葡萄糖)和代谢产物(如乳酸)等等。由于肿瘤细胞和免疫细胞对营养共同的大量需求,肿瘤微环境中的肿瘤细胞和T细胞之间会发生营养代谢竞争。这种微环境中的营养竞争已经被证明和抗肿瘤免疫抑制的发生密切相关,但同时这种关联也是复杂的和多因素的。肿瘤微环境中的共抑制分子的表达、葡萄糖的竞争、氨基酸的竞争、氧的竞争以及乳酸的分泌等等,共同成为了免疫抑制表型的重要促进因素。这些研究也给肿瘤的治疗提供了新的方向。本文从肿瘤细胞和T细胞代谢重编程出发,介绍不同的微环境因素对T细胞的影响。     

单细胞测序技术在肝癌研究中的应用

传统的细胞遗传信息研究方法是对大量混合细胞进行高通量测序,得到一群细胞基因表达的平均值,忽视了细胞间存在的异质性。肝癌作为一种人类常见的恶性致命肿瘤,其内部肿瘤细胞存在高度异质性,群体水平分析无法精确揭示其恶性细胞克隆结构和免疫微环境的细胞种类、状态和亚群分布,因此迫切需要进行单细胞水平的分析,这将有助于深入了解肝癌发病机制,进行精准肝癌分型指导临床治疗。同时发现,新型治疗靶点及有效生物标记物,为肝癌患者今后进行精准诊疗提供参考。本文综述了单细胞基因组和转录物组测序技术在肝癌免疫微环境、肝癌细胞异质性、肝癌细胞演化与诊疗和肝癌转移机制及生物标志物研究中的应用。本文还总结了在肝癌研究中,单细胞多组学测序技术在发现新肿瘤亚群、精确识别肿瘤细胞间的异质性和了解肿瘤微环境构成等方面的优势。     

蛋白激酶AKT 不同亚型影响乳腺癌恶性表型的研究进展

细胞的增殖、转移、存活等细胞生物学过程的异常对人类众多疾病尤其是恶性肿瘤的发生发展至关重要。大量研究表明,PI3K/AKT信号通路的异常激活在肿瘤的恶性转化过程中发挥重要作用并具有普遍意义。但是,目前的研究多集中于探讨AKT总的激酶活性,而往往忽视了AKT不同亚型的特异性功能。近年来在乳腺癌中的研究发现,AKT家族不同亚型的激酶分子在调控肿瘤细胞的存活、生长、增殖、代谢、转移等众多恶性表型方面发挥独特而关键的作用:与Akt1促进肿瘤细胞增殖、抑制肿瘤细胞转移的作用相反,Akt2在促进肿瘤细胞转移、抑制肿瘤细胞增殖方面发挥重要功能;此外,随着对AKT家族研究的深入,人们对Akt3的特异性生物学功能也有了新的认识。本文在此对AKT不同亚型与乳腺癌恶性表型之间关系的研究进展做一总结。     

磷酸戊糖途径重编程与肿瘤生长策略

磷酸戊糖途径(pentose phosphate pathway,PPP)是葡萄糖分解代谢的重要途径之一。PPP不仅向细胞提供核糖-5-磷酸(Ribose-5-phosphate,R5P),还提供NADPH,后者在消除细胞内的活性氧、还原生物合成中起关键作用。有鉴于此,PPP的改变直接关系到细胞的生长状态。肿瘤微环境对肿瘤细胞代谢表型的影响起着至关重要的作用。研究发现,低氧、乳酸化会促使实体肿瘤细胞增加PPP的流量,为肿瘤细胞高速增殖提供物质基础。本文结合本实验室及科学界最新研究成果,对肿瘤细胞PPP重编程以及肿瘤微环境通过PPP促导生物合成的机制进行探讨。     

抑制乳腺癌转移的两种内源性microRNA

尽管已知肿瘤细胞的转移是造成实体瘤患者死亡的主要原因,但目前人们对其分子和细胞机制仍不甚了解。基于转录水平的研究结果提示一系列基因主要在肿瘤组织中表达,并与肿瘤细胞的迁移密切相关,从而影响患者的预后和生存。这些基因赋予肿瘤细胞更易于转移的表型,增强血管生成和入侵特性,以及更改迁移微环境的能力。这些基因无疑为相应的临床研究提供靶点。     

颌下腺导管细胞与胶原海绵细胞相容性的实验研究

为探讨胶原海绵对颌下腺 (submandibulargland ,SMG)导管细胞的细胞相容性 ,采用HE染色光镜观察及免疫组化观察SMG导管细胞接种于胶原海绵后 ,细胞的生长情况。光镜下可见接种后第 1d细胞数量较少 ,分散于胶原海绵支架中间 ,第 7d细胞数量明显增加 ,免疫组织化学染色抗IV型胶原抗体染色呈阳性 ,说明细胞与支架材料之间已经有细胞外基质产生。胶原海绵具有良好的细胞相容性 ,是一种理想的支架材料。与胶原海绵复合培养 ,颌下腺导管细胞仍可保持良好的增殖能力。     

Determining Cell Number During Cell Culture using the Scepter Cell Counter

Counting cells is often a necessary but tedious step for in vitro cell culture. Consistent cell concentrations ensure experimental reproducibility and accuracy. Cell counts are important for monitoring cell health and proliferation rate, assessing immortalization or transformation, seeding cells for subsequent experiments, transfection or infection, and preparing for cell-based assays. It is important that cell counts be accurate, consistent, and fast, particularly for quantitative measurements of cellular responses.Despite this need for speed and accuracy in cell counting, 71% of 400 researchers surveyed¹ who count cells using a hemocytometer. While hemocytometry is inexpensive, it is laborious and subject to user bias and misuse, which results in inaccurate counts. Hemocytometers are made of special optical glass on which cell suspensions are loaded in specified volumes and counted under a microscope. Sources of errors in hemocytometry include: uneven cell distribution in the sample, too many or too few cells in the sample, subjective decisions as to whether a given cell falls within the defined counting area, contamination of the hemocytometer, user-to-user variation, and variation of hemocytometer filling rate².To alleviate the tedium associated with manual counting, 29% of researchers count cells using automated cell counting devices; these include vision-based counters, systems that detect cells using the Coulter principle, or flow cytometry¹. For most researchers, the main barrier to using an automated system is the price associated with these large benchtop instruments¹.The Scepter cell counter is an automated handheld device that offers the automation and accuracy of Coulter counting at a relatively low cost. The system employs the Coulter principle of impedance-based particle detection³ in a miniaturized format using a combination of analog and digital hardware for sensing, signal processing, data storage, and graphical display. The disposable tip is engineered with a microfabricated, cell- sensing zone that enables discrimination by cell size and cell volume at sub-micron and sub-picoliter resolution. Enhanced with precision liquid-handling channels and electronics, the Scepter cell counter reports cell population statistics graphically displayed as a histogram.     

Cell Physician: Reading Cell Motion

Cell motility is an essential phenomenon in almost all living organisms. It is natural to think that behavioral or shape changes of a cell bear information about the underlying mechanisms that generate these changes. Reading cell motion, namely, understanding the underlying biophysical and mechanochemical processes, is of paramount importance. The mathematical model developed in this paper determines some physical features and material properties of the cells locally through analysis of live cell image sequences and uses this information to make further inferences about the molecular structures, dynamics, and processes within the cells, such as the actin network, microdomains, chemotaxis, adhesion, and retrograde flow. The generality of the principals used in formation of the model ensures its wide applicability to different phenomena at various levels. Based on the model outcomes, we hypothesize a novel biological model for collective biomechanical and molecular mechanism of cell motion.     

细胞提取物重编程研究进展

体细胞重编程是在特定的条件下使已分化的细胞转变成为另一种细胞.体细胞重编程的方式主要有体细胞核移植技术、细胞融合技术、细胞提取物处理技术及特定转录因子转染技术.现有研究表明,细胞提取物重编程技术在体细胞重编程中发挥着一定的作用,为此,就该技术的最新研究进展和可能机制作一综述.     

Tuning Cell Motility via Cell Tension with a Mechanochemical Cell Migration Model

Cell migration is orchestrated by a complicated mechanochemical system. However, few cell migration models take into account the coupling between the biochemical network and mechanical factors. Here, we construct a mechanochemical cell migration model to study the cell tension effect on cell migration. Our model incorporates the interactions between Rac-GTP, Rac-GDP, F-actin, myosin, and cell tension, and it is very convenient in capturing the change of cell shape by taking the phase field approach. This model captures the characteristic features of cell polarization, cell shape change, and cell migration modes. It shows that cell tension inhibits migration ability monotonically when cells are applied with persistent external stimuli. On the other hand, if random internal noise is significant, the regulation of cell tension exerts a nonmonotonic effect on cell migration. Because the increase of cell tension hinders the formation of multiple protrusions, migration ability could be maximized at intermediate cell tension under random internal noise. These model predictions are consistent with our single-cell experiments and other experimental results.