细胞代谢组学用于羽扇豆醇干预人乳腺癌细胞MCF-7的机理探究

应用基于气相色谱-质谱联用（GC-MS）的代谢组学方法结合细胞周期实验,研究羽扇豆醇体外抑制人乳腺癌细胞MCF-7增殖的作用机理。代谢组学的研究结果表明：通过正交偏最小方差判别分析（OPLS-DA）可以很好地区分羽扇豆醇作用的MCF-7细胞代谢谱与对照组细胞代谢谱,模型参数为：R²Ycum=0.988,Q²Ycum=0.964。VIP（variable importance in the projection）值大于1的差异代谢物进一步用t检验进行单位分析,选择t<0.05（VIP>1）的代谢物作为羽扇豆醇作用组的生物标志物,得到琥珀酸、磷酸、亮氨酸、异亮氨酸等11种代谢差异物。结合羽扇豆醇将细胞周期抑制在G1期这一现象,推测羽扇豆醇可能是主要抑制了三羧酸循环中的琥珀酰辅酶A的生成和底物磷酸化生成ATP的反应来抑制MCF-7细胞的增殖。本实验从代谢组学角度为乳腺癌抗肿瘤机制提供新的线索。     

Development of docking-based 3D QSAR models for the design of substituted quinoline derivatives as human dihydroorotate dehydrogenase (hDHODH) inhibitors

Abstract

This study has investigated docking-based 3D quantitative structure–activity relationships (QSARs) for a range of quinoline carboxylic acid derivatives by comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). A docking study has shown that most of the compounds formed H-bonds with Arg136 and Gln47, which have already been shown to be essential for the binding of ligands at the active site of the hydroorotate dehydrogenase adenovirus (hDHODH). Bioactive conformations of all the molecules obtained from the docking study were used for the 3D QSAR study. The best CoMFA and CoMSIA models were obtained for the training set and were found to be statistically significant, with cross-validated coefficients (q² ) of 0.672 and 0.613, r² _cv of 0.635 and 0.598 and coefficients of determination (r² ) of 0.963 and 0.896, respectively. Both models were validated by a test set of 15 compounds, giving satisfactory predicted correlation coefficients (r² _pred) of 0.824 and 0.793 for the CoMFA and CoMSIA models, respectively. From the docking-based 3D QSAR study we designed 34 novel quinoline-based compounds and performed structure-based virtual screening. Finally, in silico pharmacokinetics and toxicities were predicted for 24 of the best docked molecules. The study provides valuable information for the understanding of interactions between hDHODH and the novel compounds.     

Drug Delivery Applications of Coaxial Electrospun Nanofibres in Cancer Therapy

Cancer is one of the most serious health problems and the second leading cause of death worldwide, and with an ageing and growing population, problems related to cancer will continue. In the battle against cancer, many therapies and anticancer drugs have been developed. Chemotherapy and relevant drugs are widely used in clinical practice; however, their applications are always accompanied by severe side effects. In recent years, the drug delivery system has been improved by nanotechnology to reduce the adverse effects of the delivered drugs. Among the different candidates, core–sheath nanofibres prepared by coaxial electrospinning are outstanding due to their unique properties, including their large surface area, high encapsulation efficiency, good mechanical property, multidrug loading capacity, and ability to govern drug release kinetics. Therefore, encapsulating drugs in coaxial electrospun nanofibres is a desirable method for controlled and sustained drug release. This review summarises the drug delivery applications of coaxial electrospun nanofibres with different structures and drugs for various cancer treatments.     

Modelling Protein Plasticity: The Example of Frataxin and Its Variants

Frataxin (FXN) is a protein involved in storage and delivery of iron in the mitochondria. Single-point mutations in the FXN gene lead to reduced production of functional frataxin, with the consequent dyshomeostasis of iron. FXN variants are at the basis of neurological impairment (the Friedreich’s ataxia) and several types of cancer. By using altruistic metadynamics in conjunction with the maximal constrained entropy principle, we estimate the change of free energy in the protein unfolding of frataxin and of some of its pathological mutants. The sampled configurations highlight differences between the wild-type and mutated sequences in the stability of the folded state. In partial agreement with thermodynamic experiments, where most of the analyzed variants are characterized by lower thermal stability compared to wild type, the D104G variant is found with a stability comparable to the wild-type sequence and a lower water-accessible surface area. These observations, obtained with the new approach we propose in our work, point to a functional switch, affected by single-point mutations, of frataxin from iron storage to iron release. The method is suitable to investigate wide structural changes in proteins in general, after a proper tuning of the chosen collective variable used to perform the transition.     

Expression and Characterization of Catalytic Domain of T Cell Protein Tyrosine Phosphatase(ΔTC-PTP)——Immunohistochemical Study of ΔTC-PTP Expression in Non-small Cell Lung Carcinomas

This study objective was to express and characterize the catalytic domain of the human T cell protein tyrosine phosphatase(ΔTC-PTP) and to study immunohistochemically the expression of ΔTC-PTP in human non-small cell lung cancers. ΔTC-PTP gene was PCR amplified with the cDNA of human TC-PTP as template, and cloned into the pT7 expression vector. The recombinant pT7-ΔTC-PTP was expressed in E.coli Rosetta(DE3) host cells and purified. The enzymatic characteristics of ΔTC-PTP including enzyme activity and kinetics assay were measured. The antiserum was prepared by immunizing rabbit with the purified recombinant ΔTC-PTP. Rabbit polyclonal antibody against ΔTC-PTP was purified by PVDF immobilized antigen affinity chromatography. Immunohistochemical staining of lung cancer tissues was performed with antibody against ΔTC-PTP protein. ΔTC-PTP gene was correctly cloned, expressed, and purified. The recombinant ΔTC-PTP had a highly catalytic activity of PTPase. Squamous cell lung carcinoma showed a significantly higher expression rate of ΔTC-PTP(76.92%, 10/13) than adenocarcinoma(57.14%, 4/7) and normal lung tissue(20%, 1/5). This study represents the first demonstration that ΔTC-PTP is highly expressed in human squamous cell lung carcinomas. In addition, this study provides an important basis for further studying the biological function of TC-PTP and its relationship with lung carcinomas and other diseases.     

Effects of Early Physical Therapist-supervised Walking on Clinical Outcomes after Liver Resection: Propensity Score Matching Analysis

Objective: The study aimed to demonstrate the significance of early postoperative physical therapy interventions on clinical outcomes by determining the influence of the distance walked under the supervision of a physical therapist in the early postoperative period after liver cancer. Methods: All consecutive patients who underwent surgery for liver cancer between April 2018 and March 2020 were eligible for enrollment in the study. The total walking distance during physical therapy till the third postoperative day was examined. The clinical outcomes comprised duration of postoperative hospital stay, time to independent walking, and occurrence of postoperative complications. For data analysis, the patients were divided into two groups: those who walked more than the median total distance (the long-distance group) and those who walked less than the median distance (the short-distance group). We used propensity score matching to match the background characteristics between the groups. Results: Of the 65 patients who were eligible, 14 patients were included in the two groups each, after matching. The long-distance walking group had a significantly shorter hospital stay (9.0 days vs. 11.0 days, p=0.008) and a shorter time to independent walking (3.5 days vs. 7.5 days, p=0.019) than the short-distance walking group. There were no significant differences in postoperative complications between the two groups (7.1% vs. 42.8%, p=0.08). Conclusion: In the early postoperative period after liver cancer surgery, increasing the walking distance under the supervision of a physical therapist is important for improving clinical outcomes. Further prospective studies are needed to confirm the findings of this study.     

姜黄素（Curcumin）能够升高肺癌细胞对抗肿瘤药物的敏感性

作为重要的天然药物产物,姜黄素(Curcumin)分离自Curcuma longa L.,具有多个方面的活性,包括抗氧化、抗感染和抗炎作用。最近的研究提示姜黄素可能具有一定的抗肿瘤活性,但其活性和作用机制有待深入研究。为考察姜黄素对抗肿瘤药物杀伤肺癌细胞的影响,用肺癌细胞系A549、H460、H1299以及H358使用姜黄素预处理后,分别使用抗肿瘤药物吉非替尼(Gefitinib)、舒尼替尼(Sunitinib)、吉西他滨(Gemcitabine)和紫杉醇(Paclitaxel)处理上述肺癌细胞,检测其抑制率;并计算IC50值。CCK-8实验结果显示,姜黄素能够上调抗肿瘤药物对肺癌细胞的杀伤作用,显著下调其IC50值。说明姜黄素具有增加肿瘤细胞对化疗药物敏感性的作用,具有潜在逆转化疗耐药的价值。     

肺结核合并非小细胞肺癌患者临床特征分析：一项单中心临床研究

为早期诊断肺结核合并非小细胞（PTB-NSCLC）患者,我们对其进行了临床、影像及病理资料的分析,以减少漏诊误诊的发生,做到精准诊断、精准治疗。选取我单位2016年1月至2020年12月病理诊断为PTB-NSCLC的54例患者作为病例组,同期收治的一般资料相匹配的NSCLC、PTB患者各54例作为对照组。比较PTB-NSCLC组与对照组在吸烟史、临床症状、肺结核状态、病理学特征及影像学特征等方面的差异。早期与局部晚期及进展期NSCLC在合并活动性肺结核方面差异有统计学意义（P<0.05）。PTB-NSCLC组在PS评分≥2、CT表现为结节影、空洞影方面比例高于NSCLC组（P<0.05）;在胸痛、吸烟年支分层（>400支/年）、痰培养阳性率以及肿瘤标志物CEA、CA21-1、SCC水平方面高于PTB组（P<0.05）。吸烟（OR：3.718 ;95%CI： 1.360~10.165）、空洞（OR ：4.364 ;95%CI ：1.419~13.427)、纤维钙化（OR：2.917;95%CI：1.082~7.861）与肺癌发生风险升高正相关,糖尿病、CT表现为多种形式与肺癌发生负相关。在鉴别PTB-NSCLC患者、单纯性NSCLC、单纯PTB三者时,尽管根据临床表现、影像学特征以及葡萄糖代谢的最大SUV值难以鉴别,但根据吸烟、结节影、空洞、PS评分、痰培养阳性率情况,且在纳入多因素分析后,提示具有多年吸烟史（>400支/年）、CT表现为结节影、空洞、PS评分≥2有助于早期诊断及鉴别PTB-NSCLC。局部晚期及进展期NSCLC更易合并活动性肺结核。同时,在肺结核患者中,具有吸烟史、伴有纤维钙化病变是肺癌发生的危险因素。     

抗癌药物L-天冬酰胺酶摇瓶发酵研究

对大肠杆菌 Ｌ－ 天冬酰胺酶的摇瓶发酵进行了研究。在最适条件下发酵 １２ｈ，可使产酶达到６０ｕ／ｍ ｌ。在培养基中添加 ００１％ 硫酸亚铁和 ２％ 的 Ｗ 试剂可分别提高产酶能力 １５％ 和２８％ 。该发酵过程是一个耗氧很大的过程。     

Tetraarsenic Tetrasulfide Induced Colon Cancer ls174t Cells Apoptosis

To explore the functional mechanism of tetraarsenic tetrasulfide(As4S4)against the growth and proliferation of colon cancer cells ls174t,MTT method was used to observe the functions of tetraarsenic tetrasulfide for the inhibition of cells ls174t in vitro.Transmission electron microscope was used to observe cell morphologies.FCM assay was performed to measure the change of cell cycle.RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA.Westernblot method was used to detect the expressions of bcl-2 and bax protein.Tetraarsenic tetrasulfide showed an inhibiting effect on the proliferation of cells ls174t in vitro(P＜0.01).It induces the apoptosis of cells ls174t,which is related to the decrease in the expression of bcl-2 and the increase in the expression of bax.