Identification of New Regulators of Pancreatic Cancer Cell Sensitivity to Oxaliplatin and Cisplatin

The chemoresistance of tumor cells is one of the most urgent challenges in modern oncology and in pancreatic cancer, in which this problem is the most prominent. Therefore, the identification of new chemosensitizing co-targets may be a path toward increasing chemotherapy efficacy. In this work, we performed high-performance in vitro knockout CRISPR/Cas9 screening to find potential regulators of the sensitivity of pancreatic cancer. For this purpose, MIA PaCa-2 cells transduced with two sgRNA libraries (“cell cycle/nuclear proteins genes” and “genome-wide”) were screened by oxaliplatin and cisplatin. In total, 173 candidate genes were identified as potential regulators of pancreatic cancer cell sensitivity to oxaliplatin and/or cisplatin; among these, 25 genes have previously been reported, while 148 genes were identified for the first time as potential platinum drug sensitivity regulators. We found seven candidate genes involved in pancreatic cancer cell sensitivity to both cisplatin and oxaliplatin. Gene ontology enrichment analysis reveals the enrichment of single-stranded DNA binding, damaged DNA binding pathways, and four associated with NADH dehydrogenase activity. Further investigation and validation of the obtained results by in vitro, in vivo, and bioinformatics approaches, as well as literature analysis, will help to identify novel pancreatic cancer platinum sensitivity regulators.     

偶氮苯衍生物探针在乏氧细胞成像中的应用

细胞不受控制的生长增殖和异常的血管系统导致肿瘤部位氧气供应不足,氧气浓度低于正常组织.细胞乏氧是大多数实体瘤的共同特征,可用作恶性组织和癌症进展的指标.准确的乏氧检测和成像对癌症患者的诊断和临床治疗至关重要.荧光成像具有高灵敏度、无创、实时等优点,常被用于癌症检查.偶氮基团由于其对荧光基团的荧光猝灭作用和还原断裂荧光恢...     

双电解池正反馈示波计时电位法研究

双电解池正反馈示波计时电位法研究郑建斌，高鸿，朱俊杰，胡娟（西北大学电分析化学研究所，西安，７１００６９）（南京大学化学系）关键词正反馈示波计时电位法，双电解池，切口由于在经典示波计时电位法中所施加的交流极化电流的频率很高，充电电流就构成了影响去极剂...     

单细胞分析中的荧光标记化学*

细胞内组分复杂、含量低,因此测定单细胞内化学组分的分析方法必须具有灵敏度高、选择性好和分辨率高的特点。高灵敏度的荧光检测技术是单细胞分析中应用最多的检测方法之一。但是细胞内绝大部分物质其天然态是没有荧光的,且由于细胞膜的阻碍,衍生试剂不能自由地进入细胞内。为了使衍生试剂透过细胞膜标记细胞内待测物质而不引起显著的稀释效应,已进行了大量的研究工作。本文综述了在单细胞分析中常用的荧光标记方法,包括细胞作为微反应器的衍生法,借助于脂质体与聚乙二醇（PEG）等增加细胞膜通透性的衍生方法和在毛细管/芯片毛细管电泳分析单细胞时柱上衍生和柱后衍生法以及量子点的标记法等。对这些方法的原理、特点和在单细胞分析中的应用也做了较为详细的阐述。     

Photodynamic Therapy with Tumor Cell Discrimination through RNA-Targeting Ability of Photosensitizer

Photodynamic therapy (PDT) represents an effective treatment to cure cancer. The targeting ability of the photosensitizer is of utmost importance. Photosensitizers that discriminate cancer cells can avoid the killing of normal cells and improve PDT efficacy. However, the design and synthesis of photosensitizers conjugated with a recognition unit of cancer cell markers is complex and may not effectively target cancer. Considering that the total RNA content in cancer cells is commonly higher than in normal cells, this study has developed the photosensitizer QICY with RNA-targeting abilities for the discrimination of cancer cells. QICY was specifically located in cancer cells rather than normal cells due to their stronger electrostatic interactions with RNA, thereby further improving the PDT effects on the cancer cells. After intravenous injection into mice bearing a xenograft tumor, QICY accumulated into the tumor location through the enhanced permeability and retention effect, automatically targeted cancer cells under the control of RNA, and inhibited tumor growth under 630 nm laser irradiation without obvious side effects. This intelligent photosensitizer with RNA-targeting ability not only simplifies the design and synthesis of cancer-cell-targeting photosensitizers but also paves the way for the further development of highly efficient PDTs.     

Synthetic Peptide ΔM4-Induced Cell Death Associated with Cytoplasmic Membrane Disruption,Mitochondrial Dysfunction and Cell Cycle Arrest in Human Melanoma Cells

Melanoma is the most dangerous and lethal form of skin cancer, due to its ability to spread to different organs if it is not treated at an early stage. Conventional chemotherapeutics are failing as a result of drug resistance and weak tumor selectivity. Therefore, efforts to evaluate novel molecules for the treatment of skin cancer are necessary. Antimicrobial peptides have become attractive anticancer agents because they execute their biological activity with features such as a high potency of action, a wide range of targets, and high target specificity and selectivity. In the present study, the antiproliferative activity of the synthetic peptide ΔM4 on A375 human melanoma cells and spontaneously immortalized HaCaT human keratinocytes was investigated. The cytotoxic effect of ΔM4 treatment was evaluated through propidium iodide uptake by flow cytometry. The results indicated selective toxicity in A375 cells and, in order to further investigate the mode of action, assays were carried out to evaluate morphological changes, mitochondrial function, and cell cycle progression. The findings indicated that ΔM4 exerts its antitumoral effects by multitarget action, causing cell membrane disruption, a change in the mitochondrial transmembrane potential, an increase of reactive oxygen species, and cell cycle accumulation in S-phase. Further exploration of the peptide may be helpful in the design of novel anticancer peptides.     

Cell Tracking with Caged Xenon: Using Cryptophanes as MRI Reporters upon Cellular Internalization

Caged xenon has great potential in overcoming sensitivity limitations for solution‐state NMR detection of dilute molecules. However, no application of such a system as a magnetic resonance imaging (MRI) contrast agent has yet been performed with live cells. We demonstrate MRI localization of cells labeled with caged xenon in a packed‐bed bioreactor working under perfusion with hyperpolarized‐xenon‐saturated medium. Xenon hosts enable NMR/MRI experiments with switchable contrast and selectivity for cell‐associated versus unbound cages. We present MR images with 10³‐fold sensitivity enhancement for cell‐internalized, dual‐mode (fluorescence/MRI) xenon hosts at low micromolar concentrations. Our results illustrate the capability of functionalized xenon to act as a highly sensitive cell tracer for MRI detection even without signal averaging. The method will bridge the challenging gap for translation to in vivo studies for the optimization of targeted biosensors and their multiplexing applications.     

Zinc-Based Metal-Organic Frameworks in Drug Delivery,Cell Imaging,and Sensing

The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs’ chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions.     

DNA Dyes—Highly Sensitive Reporters of Cell Quantification: Comparison with Other Cell Quantification Methods

Cell quantification is widely used both in basic and applied research. A typical example of its use is drug discovery research. Presently, plenty of methods for cell quantification are available. In this review, the basic techniques used for cell quantification, with a special emphasis on techniques based on fluorescent DNA dyes, are described. The main aim of this review is to guide readers through the possibilities of cell quantification with various methods and to show the strengths and weaknesses of these methods, especially with respect to their sensitivity, accuracy, and length. As these methods are frequently accompanied by an analysis of cell proliferation and cell viability, some of these approaches are also described.     

In vivo Fluorescence Imaging of Tumors using Molecular Aptamers Generated by Cell‐SELEX

Poor sensitivity and low specificity of current molecular imaging probes limit their application in clinical settings. To address these challenges, we used a process known as cell‐SELEX to develop unique molecular probes termed aptamers with the high binding affinity, sensitivity, and specificity needed for in vivo molecular imaging inside living animals. Importantly, aptamers can be selected by cell‐SELEX to recognize target cells, or even surface membrane proteins, without requiring prior molecular signature information. As a result, we are able to present the first report of aptamers molecularly engineered with signaling molecules and optimized for the fluorescence imaging of specific tumor cells inside a mouse. Using a Cy5‐labeled aptamer TD05 (Cy5‐TD05) as the probe, the in vivo efficacy of aptamer‐based molecular imaging in Ramos (B‐cell lymphoma) xenograft nude mice was tested. After intravenous injection of Cy5‐TD05 into mice bearing grafted tumors, noninvasive, whole‐body fluorescence imaging then allowed the spatial and temporal distribution to be directly monitored. Our results demonstrate that the aptamers could effectively recognize tumors with high sensitivity and specificity, thus establishing the efficacy of these fluorescent aptamers for diagnostic applications and in vivo studies requiring real‐time molecular imaging.     

YSZ中温燃料电池的稳态模拟

依据同时考虑电化学及热平衡耦合的二维模拟软件 ,计算了薄膜钇稳氧化锆 (YSZ)中温燃料电池在不同工作条件下的稳态特性 .通过电流～电压关系参数进行自拟合实验 ,格点选取由平衡收敛性和计算效率而得 ,研究了不同连接体、气流流向设计等工作条件下的温度场 ,给出了不同工作温度下输出功率及电池效率与工作电压的关系 .对温度场的分析表明 :电池板内最高温度及最大温差以并流为最小 ,交叉流为最大 ,并流是最好的气流流向设计 .与以陶瓷材料作连接体相比 ,使用金属连接体能显著减小热应力和电池板内最高温度 ,受益最大的是交叉流 ,其最高温度及最大温差均小于陶瓷连接体的并流设计 .不同的气流流向对于输出功率及电池效率影响很小 ,对并流和金属连接体组合 ,给出了工程设计的燃料分布、电流密度、Nernst势及温度梯度在典型工作条件下的情形     

Synergistic Roles of Curcumin in Sensitising the Cisplatin Effect on a Cancer Stem Cell-Like Population Derived from Non-Small Cell Lung Cancer Cell Lines

Cancer stem cells (CSCs) represent a small subpopulation within a tumour. These cells possess stem cell-like properties but also initiate resistance to cytotoxic agents, which contributes to cancer relapse. Natural compounds such as curcumin that contain high amounts of polyphenols can have a chemosensitivity effect that sensitises CSCs to cytotoxic agents such as cisplatin. This study was designed to investigate the efficacy of curcumin as a chemo-sensitiser in CSCs subpopulation of non-small cell lung cancer (NSCLC) using the lung cancer adenocarcinoma human alveolar basal epithelial cells A549 and H2170. The ability of curcumin to sensitise lung CSCs to cisplatin was determined by evaluating stemness characteristics, including proliferation activity, colony formation, and spheroid formation of cells treated with curcumin alone, cisplatin alone, or the combination of both at 24, 48, and 72 h. The mRNA level of genes involved in stemness was analysed using quantitative real-time polymerase chain reaction. Liquid chromatography-mass spectrometry was used to evaluate the effect of curcumin on the CSC niche. A combined treatment of A549 subpopulations with curcumin reduced cellular proliferation activity at all time points. Curcumin significantly (p < 0.001) suppressed colonies formation by 50% and shrank the spheroids in CSC subpopulations, indicating inhibition of their self-renewal capability. This effect also was manifested by the down-regulation of SOX2, NANOG, and KLF4. Curcumin also regulated the niche of CSCs by inhibiting chemoresistance proteins, aldehyde dehydrogenase, metastasis, angiogenesis, and proliferation of cancer-related proteins. These results show the potential of using curcumin as a therapeutic approach for targeting CSC subpopulations in non-small cell lung cancer.     

Cyclin-Dependent Kinase 4 and 6 Inhibitors in Cell Cycle Dysregulation for Breast Cancer Treatment

In cell development, the cell cycle is crucial, and the cycle progression’s main controllers are endogenous CDK inhibitors, cyclin-dependent kinases (CDKs), and cyclins. In response to the mitogenic signal, cyclin D is produced and retinoblastoma protein (Rb) is phosphorylated due to activated CDK4/CDK6. This causes various proteins required in the cell cycle progression to be generated. In addition, complexes of CDK1-cyclin A/B, CDK2-cyclin E/A, and CDK4/CDK6-cyclin D are required in each phase of this progression. Cell cycle dysregulation has the ability to lead to cancer. Based on its role in the cell cycle, CDK has become a natural target of anticancer therapy. Therefore, understanding the CDK structures and the complex formed with the drug, helps to foster the development of CDK inhibitors. This development starts from non-selective CDK inhibitors to selective CDK4/CDK6 inhibitors, and these have been applied in clinical cancer treatment. However, these inhibitors currently require further development for various hematologic malignancies and solid tumors, based on the results demonstrated. In drug development, the main strategy is primarily to prevent and asphyxiate drug resistance, thus a determination of specific biomarkers is required to increase the therapy’s effectiveness as well as patient selection suitability in order to avoid therapy failure. This review is expected to serve as a reference for early and advanced-stage researchers in designing new molecules or repurposing existing molecules as CDK4/CDK6 inhibitors to treat breast cancer.     

Effects of Various Cell Surface Engineering Reactions on the Biological Behavior of Mammalian Cells

Cell surface engineering technologies can regulate cell function and behavior by modifying the cell surface. Previous studies have mainly focused on investigating the effects of cell surface engineering reactions and materials on cell activity. However, they do not comprehensively analyze other cellular processes. This study exploits covalent bonding, hydrophobic interactions, and electrostatic interactions to modify the macromolecules succinimide ester-methoxy polyethylene glycol (NHS-mPEG), distearoyl phosphoethanolamine-methoxy polyethylene glycol (DSPE-mPEG), and poly-L -lysine (PLL), respectively, on the cell surface. This work systematically investigates the effects of the three surface engineering reactions on the behavior of human umbilical vein endothelial cells (HUVECs) and human skin fibroblasts, including viability, growth, proliferation, cell cycle, adhesion, and migration. The results reveals that the PLL modification method notably affects cell viability and G2/M arrest and has a short modification duration. However, the DSPE-mPEG and NHS-mPEG modification methods have little effect on cell viability and proliferation but have a prolonged modification duration. Moreover, the DSPE-mPEG modification method highly affects cell adherence. Further, the NHS-mPEG modification method can significantly improve the migration ability of HUVECs by reducing the area of focal adhesions. The findings of this study will contribute to the application of cell surface engineering technology in the biomedical field.     

Nanoparticle‐Mediated Immunogenic Cell Death Enables and Potentiates Cancer Immunotherapy

Cancer immunotherapies that train or stimulate the inherent immunological systems to recognize, attack, and eradicate tumor cells with minimal damage to healthy cells have demonstrated promising clinical responses in recent years. However, most of these immunotherapeutic strategies only benefit a small subset of patients and cause systemic autoimmune side effects in some patients. Immunogenic cell death (ICD)‐inducing modalities not only directly kill cancer cells but also induce antitumor immune responses against a broad spectrum of solid tumors. Such strategies for generating vaccine‐like functions could be used to stimulate a “cold” tumor microenvironment to become an immunogenic, “hot” tumor microenvironment, working in synergy with immunotherapies to increase patient response rates and lead to successful treatment outcomes. This Minireview will focus on nanoparticle‐based treatment modalities that can induce and enhance ICD to potentiate cancer immunotherapy.     

In Situ Scatheless Cell Detachment Reveals Correlation between Adhesion Strength and Viability at Single‐Cell Resolution

Single‐cell biology provides insights into some of the most fundamental processes in biology and promotes the understanding of life's mysteries. As the technologies to study single‐cells expand, they will require sophisticated analytical tools to make sense of various behaviors and components of single‐cells as well as their relations in the adherent tissue culture. In this paper, we revealed cell heterogeneity and uncovered the connections between cell adhesion strength and cell viability at single‐cell resolution by extracting single adherent cells of interest from a standard tissue culture by using a microfluidic chip‐based live single‐cell extractor (LSCE). We believe that this method will provide a valuable new tool for single‐cell biology.     

Droplet Microfluidics—A Tool for Single‐Cell Analysis

Droplet microfluidics allows the isolation of single cells and reagents in monodisperse picoliter liquid capsules and manipulations at a throughput of thousands of droplets per second. These qualities allow many of the challenges in single‐cell analysis to be overcome. Monodispersity enables quantitative control of solute concentrations, while encapsulation in droplets provides an isolated compartment for the single cell and its immediate environment. The high throughput allows the processing and analysis of the tens of thousands to millions of cells that must be analyzed to accurately describe a heterogeneous cell population so as to find rare cell types or access sufficient biological space to find hits in a directed evolution experiment. The low volumes of the droplets make very large screens economically viable. This Review gives an overview of the current state of single‐cell analysis involving droplet microfluidics and offers examples where droplet microfluidics can further biological understanding.     

Glycocalyx Engineering with a Recycling Glycopolymer that Increases Cell Survival In Vivo

Synthetic glycopolymers that emulate cell‐surface mucins have been used to elucidate the role of mucin overexpression in cancer. However, because they are internalized within hours, these glycopolymers could not be employed to probe processes that occur on longer time scales. In this work, we tested a panel of glycopolymers bearing a variety of lipids to identify those that persist on cell membranes. Strikingly, we found that cholesterylamine (CholA) anchored glycopolymers are internalized into vesicles that serve as depots for delivery back to the cell surface, allowing for the display of cell‐surface glycopolymers for at least ten days, even while the cells are dividing. As with native mucins, the cell‐surface display of CholA‐anchored glycopolymers influenced the focal adhesion distribution. Furthermore, we show that these mimetics enhance the survival of nonmalignant cells in a zebrafish model of metastasis. CholA‐anchored glycopolymers therefore expand the application of glycocalyx engineering in glycobiology.     

Natural Peptides Inducing Cancer Cell Death: Mechanisms and Properties of Specific Candidates for Cancer Therapeutics

Nowadays, cancer has become the second highest leading cause of death, and it is expected to continue to affect the population in forthcoming years. Additionally, treatment options will become less accessible to the public as cases continue to grow and disease mechanisms expand. Hence, specific candidates with confirmed anticancer effects are required to develop new drugs. Among the novel therapeutic options, proteins are considered a relevant source, given that they have bioactive peptides encrypted within their sequences. These bioactive peptides, which are molecules consisting of 2–50 amino acids, have specific activities when administered, producing anticancer effects. Current databases report the effects of peptides. However, uncertainty is found when their molecular mechanisms are investigated. Furthermore, analyses addressing their interaction networks or their directly implicated mechanisms are needed to elucidate their effects on cancer cells entirely. Therefore, relevant peptides considered as candidates for cancer therapeutics with specific sequences and known anticancer mechanisms were accurately reviewed. Likewise, those features which turn certain peptides into candidates and the mechanisms by which peptides mediate tumor cell death were highlighted. This information will make robust the knowledge of these candidate peptides with recognized mechanisms and enhance their non-toxic capacity in relation to healthy cells and further avoid cell resistance.