羧基化荧光碳量子点的合成及其在汞离子检测中的应用

通过一步法高压热处理柠檬酸粉末制备了羧基功能化的荧光碳量子点,荧光光谱表征显示所合成荧光碳量子点的最大激发波长为316 nm,最大发射波长为394 nm。Hg²⁺对其具有较好的淬灭效果,在5～300μmol/L的浓度范围内,Hg²⁺的浓度和体系荧光强度呈较好的线性关系,线性回归方程为F₀=152.169 5-0.153 5c,相关系数R²=0.998。这种碳量子点的制备技术将为合成功能化荧光纳米材料提供有益的借鉴作用,并为开发新型传感检测技术提供理论支持。     

Liver Toxicity of Cadmium Telluride Quantum Dots (CdTe QDs) Due to Oxidative Stress in Vitro and in Vivo

With the applications of quantum dots (QDs) expanding, many studies have described the potential adverse effects of QDs, yet little attention has been paid to potential toxicity of QDs in the liver. The aim of this study was to investigate the effects of cadmium telluride (CdTe) QDs in mice and murine hepatoma cells alpha mouse liver 12 (AML 12). CdTe QDs administration significantly increased the level of lipid peroxides marker malondialdehyde (MDA) in the livers of treated mice. Furthermore, CdTe QDs caused cytotoxicity in AML 12 cells in a dose- and time-dependent manner, which was likely mediated through the generation of reactive oxygen species (ROS) and the induction of apoptosis. An increase in ROS generation with a concomitant increase in the gene expression of the tumor suppressor gene p53, the pro-apoptotic gene Bcl-2 and a decrease in the anti-apoptosis gene Bax, suggested that a mitochondria mediated pathway was involved in CdTe QDs’ induced apoptosis. Finally, we showed that NF-E2-related factor 2 (Nrf2) deficiency blocked induced oxidative stress to protect cells from injury induced by CdTe QDs. These findings provide insights into the regulatory mechanisms involved in the activation of Nrf2 signaling that confers protection against CdTe QDs-induced apoptosis in hepatocytes.     

Preparation and Characterization of Highly Fluorescent, Glutathione-coated Near Infrared Quantum Dots for in Vivo Fluorescence Imaging

Fluorescent probes that emit in the near-infrared (NIR, 700–1,300 nm) region are suitable as optical contrast agents for in vivo fluorescence imaging because of low scattering and absorption of the NIR light in tissues. Recently, NIR quantum dots (QDs) have become a new class of fluorescent materials that can be used for in vivo imaging. Compared with traditional organic fluorescent dyes, QDs have several unique advantages such as size- and composition-tunable emission, high brightness, narrow emission bands, large Stokes shifts, and high resistance to photobleaching. In this paper, we report a facile method for the preparation of highly fluorescent, water-soluble glutathione (GSH)-coated NIR QDs for in vivo imaging. GSH-coated NIR QDs (GSH-QDs) were prepared by surface modification of hydrophobic CdSeTe/CdS (core/shell) QDs. The hydrophobic surface of the CdSeTe/CdS QDs was exchanged with GSH in tetrahydrofuran-water. The resulting GSH-QDs were monodisperse particles and stable in PBS (phosphate buffered saline, pH = 7.4). The GSH-QDs (800 nm emission) were highly fluorescent in aqueous solutions (quantum yield = 22% in PBS buffer), and their hydrodynamic diameter was less than 10 nm, which is comparable to the size of proteins. The cellular uptake and viability for the GSH-QDs were examined using HeLa and HEK 293 cells. When the cells were incubated with aqueous solutions of the GSH-QDs (10 nM), the QDs were taken into the cells and distributed in the perinuclear region of both cells. After 12 hrs incubation of 4 nM of GSH-QDs, the viabilities of HeLa and HEK 293 cells were ca. 80 and 50%, respectively. As a biomedical utility of the GSH-QDs, in vivo NIR-fluorescence imaging of a lymph node in a mouse is presented.     

肺癌抑癌基因1对鼻咽癌细胞株HNE-1增殖与侵袭能力的影响

目的探讨肺癌抑癌基因1(Tumor suppressor in lung cancer 1,TSLC1)对鼻咽癌细胞株HNE-1增殖与侵袭能力的影响。方法采用RT-PCR法从乳腺癌细胞株MCF-7中扩增TSLC1基因全长编码区序列,构建重组真核表达质粒pcDNA3.1-TSLC1,转染HNE-1细胞,RT-PCR及Western blot检测TSLC1基因mRNA和蛋白的表达水平。MTT和Transwell小室试验检测TSLC1基因过表达对HNE-1细胞增殖及侵袭能力的影响。结果重组表达质粒pcDNA3.1-TSLC1经双酶切及测序证明构建正确;稳定转染重组表达质粒的HNE-1细胞中TSLC1基因出现过表达;TSLC1基因过表达可显著抑制HNE-1细胞的增殖与侵袭能力。结论 TSLC1基因过表达对HNE-1细胞增殖与侵袭能力具有明显的抑制作用,为鼻咽癌的基因治疗提供了理想的分子靶点。     

The Anti-Proliferative and Apoptotic Effects of Rutaecarpine on Human Esophageal Squamous Cell Carcinoma Cell Line CE81T/VGH In Vitro and In Vivo

The overall five-year survival rate for patients with esophageal cancer is low (15 to 25%) because of the poor prognosis at earlier stages. Rutaecarpine (RTP) is a bioalkaloid found in the traditional Chinese herb Evodia rutaecarpa and has been shown to exhibit anti-proliferative effect on tumor cells. However, the mechanisms by which RTP confer these effects and its importance in esophageal squamous cell carcinoma treatment remain unclear. Thus, in the present study, we first incubated human esophageal squamous cell carcinoma cell line, CE81T/VGH, with RTP to evaluate RTP’s effects on tumor cell growth and apoptosis. We also performed a xenograft study to confirm the in vitro findings. Furthermore, we determined the expression of p53, Bax, bcl-2, caspase-3, caspase-9, and PCNA in CE81T/VGH cells or the tumor tissues to investigate the possible mechanisms. All the effects of TRP were compared with that of cisplatin. The results showed that RTP significantly inhibits CE81T/VGH cell growth, promotes arrest of cells in the G₂/M phase, and induces apoptosis. Consistently, the in vivo study showed that tumor size, tumor weight, and proliferating cell nuclear antigen protein expression in tumor tissue are significantly reduced in the high-dose RTP treatment group. Furthermore, the in vitro and in vivo studies showed that RTP increases the expression of p53 and Bax proteins, while inhibiting the expression of Bcl-2 in cancer cells. In addition, RTP significantly increases the expression of cleaved caspase-9 and cleaved caspase-3 proteins in tumor tissues in mice. These results suggest that RTP may trigger the apoptosis and inhibit growth in CE81T/VGH cells by the mechanisms associated with the regulation of the expression of p53, Bax, Bcl-2, as well as caspase-9 and caspase-3.     

Chick Chorioallantoic Membrane (CAM) Assay as an In Vivo Model to Study the Effect of Newly Identified Molecules on Ovarian Cancer Invasion and Metastasis

The majority of ovarian cancer patients present with advanced disease and despite aggressive treatment, prognosis remains poor. Significant improvement in ovarian cancer survival will require the development of more effective molecularly targeted therapeutics. Commonly, mouse models are used for the in vivo assessment of potential new therapeutic targets in ovarian cancer. However, animal models are costly and time consuming. Other models, such as the chick embryo chorioallantoic membrane (CAM) assay, are therefore an attractive alternative. CAM assays have been widely used to study angiogenesis and tumor invasion of colorectal, prostate and brain cancers. However, there have been limited studies that have used CAM assays to assess ovarian cancer invasion and metastasis. We have therefore developed a CAM assay protocol to monitor the metastatic properties of ovarian cancer cells (OVCAR-3, SKOV-3 and OV-90) and to study the effect of potential therapeutic molecules in vivo. The results from the CAM assay are consistent with cancer cell motility and invasion observed in in vitro assays. Our results demonstrate that the CAM assay is a robust and cost effective model to study ovarian cancer cell metastasis. It is therefore a very useful in vivo model for screening of potential novel therapeutics.     

The Effect of Self-Assembling Peptide RADA16-I on the Growth of Human Leukemia Cells in Vitro and in Nude Mice

Nanofiber scaffolds formed by self-assembling peptide RADA16-I have been used for the study of cell proliferation to mimic an extracellular matrix. In this study, we investigated the effect of RADA16-I on the growth of human leukemia cells in vitro and in nude mice. Self-assembly assessment showed that RADA16-I molecules have excellent self-assembling ability to form stable nanofibers. MTT assay displayed that RADA16-I has no cytotoxicity for leukemia cells and human umbilical vein endothelial cells (HUVECs) in vitro. However, RADA16-I inhibited the growth of K562 tumors in nude mice. Furthermore, we found RADA16-I inhibited vascular tube-formation by HUVECs in vitro. Our data suggested that nanofiber scaffolds formed by RADA16-I could change tumor microenvironments, and inhibit the growth of tumors. The study helps to encourage further design of self-assembling systems for cancer therapy.     

Characterization and Differentiation of the Tumor Microenvironment (TME) of Orthotopic and Subcutaneously Grown Head and Neck Squamous Cell Carcinoma (HNSCC) in Immunocompetent Mice

For the development and evaluation of new head and neck squamous cell carcinoma (HNSCC) therapeutics, suitable, well-characterized animal models are needed. Thus, by analyzing orthotopic versus subcutaneous models of HNSCC in immunocompetent mice, we evaluated the existence of adenosine-related immunosuppressive B- and T lymphocyte populations within the tumor microenvironment (TME). Applying the SCC VII model for the induction of HNSCC in immunocompetent C3H/HeN mice, the cellular TME was characterized after tumor initiation over time by flow cytometry. The TME in orthotopic grown tumors revealed a larger population of tumor-infiltrating lymphocytes (TIL) with more B cells and CD4⁺ T cells than the subcutaneously grown tumors. Immune cell populations in the blood and bone marrow showed a rather distinct reaction toward tumor induction and tumor location compared to the spleen, lymph nodes, or thymus. In addition, large numbers of immunosuppressive B- and T cells were identified within the TME but also in secondary lymphoid organs, independently of the tumor initiation site. The altered immunogenic TME may influence the response to any treatment attempt. Moreover, when analyzing the TME and other lymphoid organs of tumor-bearing mice, we observed conditions reflecting largely those of patients suffering from HNSCC suggesting the C3H/HeN mouse model as a suitable tool for studies aiming to target immunosuppression to improve anti-cancer therapies.     

Effect of Soluble Adenylyl Cyclase (ADCY10) Inhibitors on the LH-Stimulated cAMP Synthesis in Mltc-1 Leydig Cell Line

In contrast to all transmembrane adenylyl cyclases except ADCY9, the cytosolic soluble adenylyl cyclase (ADCY10) is insensitive to forskolin stimulation and is uniquely modulated by calcium and bicarbonate ions. In the present paper, we focus on ADCY10 localization and a kinetic analysis of intracellular cAMP accumulation in response to human LH in the absence or presence of four different ADCY10 inhibitors (KH7, LRE1, 2-CE and 4-CE) in MTLC-1 cells. ADCY10 was immuno-detected in the cytoplasm of MLTC-1 cells and all four inhibitors were found to inhibit LH-stimulated cAMP accumulation and progesterone level in MLTC-1 and testosterone level primary Leydig cells. Interestingly, similar inhibitions were also evidenced in mouse testicular Leydig cells. In contrast, the tmAC-specific inhibitors ddAdo3′ and ddAdo5′, even at high concentration, exerted weak or no inhibition on cAMP accumulation, suggesting an important role of ADCY10 relative to tmACs in the MLTC-1 response to LH. The strong synergistic effect of HCO₃⁻ under LH stimulation further supports the involvement of ADCY10 in the response to LH.     

In Vitro Characterization of Sphingosine 1-Phosphate Receptor 1 (S1P1) Expression and Mediated Migration of Primary Human T and B Cells in the Context of Cenerimod,a Novel,Selective S1P1 Receptor Modulator

Cenerimod is a potent, selective sphingosine 1-phosphate receptor 1 (S1P₁) modulator currently investigated in a Phase IIb study in patients with systemic lupus erythematosus (SLE) ({"type":"clinical-trial","attrs":{"text":"NCT03742037","term_id":"NCT03742037"}}NCT03742037). S1P₁ receptor modulators sequester circulating lymphocytes within lymph nodes, thereby reducing pathogenic autoimmune cells (including T and B lymphocytes) in the bloodstream and inflamed tissues, making them an effective therapeutic concept for autoimmune disorders. Although the effect of S1P receptor modulators in reducing circulating lymphocytes is well documented, the precise molecular role of the S1P₁ receptor on these cell types is not fully understood. In this study, the mode of action of cenerimod on human primary lymphocytes in different activation states was investigated focusing on their chemotactic behavior towards S1P in real-time, concomitant to S1P₁ receptor expression and internalization dynamics. Here, we show that cenerimod effectively prevents T and B cell migration in a concentration-dependent manner. Interestingly, while T cell activation led to strong S1P₁ re-expression and enhanced migration; in B cells, an enhanced migration capacity and S1P₁ receptor surface expression was observed in an unstimulated state. Importantly, concomitant treatment with glucocorticoids (GCs), a frequently used treatment for autoimmune disorders, had no impact on the inhibitory activity of cenerimod on lymphocytes.     

The Influence of Cold Atmospheric Pressure Plasma-Treated Media on the Cell Viability,Motility, and Induction of Apoptosis in Human Non-Metastatic (MCF7) and Metastatic (MDA-MB-231) Breast Cancer Cell Lines

Breast cancer remains the most common type of cancer, occurring in middle-aged women, and often leads to patients’ death. In this work, we applied a cold atmospheric pressure plasma (CAPP)-based reaction-discharge system, one that is unique in its class, for the production of CAPP-activated media (DMEM and Opti-MEM); it is intended for further uses in breast cancer treatment. To reach this aim, different volumes of DMEM or Opti-MEM were treated by CAPP. Prepared media were exposed to the CAPP treatment at seven different time intervals and examined in respect of their impact on cell viability and motility, and the induction of the apoptosis in human non-metastatic (MCF7) and metastatic (MDA-MB-231) breast cancer cell lines. As a control, the influence of CAPP-activated media on the viability and motility, and the type of the cell death of the non-cancerous human normal MCF10A cell line, was estimated. Additionally, qualitative and quantitative analyses of the reactive oxygen and nitrogen species (RONS), generated during the CAPP operation in contact with analyzed media, were performed. Based on the conducted research, it was found that 180 s (media activation time by CAPP) should be considered as the minimal toxic dose, which significantly decreases the cell viability and the migration of MDA-MB-231 cells, and also disturbs life processes of MCF7 cells. Finally, CAPP-activated media led to the apoptosis of analyzed cell lines, especially of the metastatic MDA-MB-231 cell line. Therefore, the application of the CAPP system may be potentially applied as a therapeutic strategy for the management of highly metastatic human breast cancer.