小鼠腹水型肝癌淋巴道高转移细胞系HCa-P/L_6细胞模型的建立及其药物敏感性的评价

[目的]建立小鼠腹水型肝癌淋巴道高转移细胞系HCa-P/L6细胞模型并应用姜黄素对该模型的药物敏感性进行评价。[方法]将小鼠腹水型肝癌淋巴道低转移细胞株（HCa-P）经615小鼠腹中线皮下接种的方法获得淋巴结转移瘤1代细胞HCa-P/L1,再经小鼠淋巴系统筛选5次,筛选高转移细胞系HCa-P/L6。用15～240μmol·L^-1姜黄素（Curcumin,Cur）分别处理人肝癌细胞系（SMC7721和HepG2）和小鼠腹水型肝癌细胞（HCa-P/L6和HCa-P）48h,以MTT法考察4种细胞的药物敏感性。以非细胞毒性最大剂量Cur作用于HCa-P/L6和HCa-P,以生长曲线和群体倍增时间评估药物对细胞生长的影响,以流式细胞仪检 测药物对细胞周期分布的影响,考察两株小鼠腹水型肝癌细胞与姜黄素作用敏感性的差异。[结果]从HCa-P中筛选出具有多部位转移特性的淋巴道高转移细胞系HCa-P/L6,转移率为100%。Cur明显抑制小鼠腹水型肝癌和人肝癌细胞的增殖,并呈 剂量依赖性（方差分析P〈0.05）。在30～120μmol·L^-1,Cur对小鼠肝癌的抑制作用强于对人肝癌的抑制作用;在60～240μmol·L^-1范围内,Cur对HCa-P/L6的抑制作用强于对HCa-P。在非细胞毒性最大剂量15μmol·L^-1 Cur作用下,HCa-P/L6和HCa-P的生长受到抑制（t检验P〈0.05）,并且呈时间依赖性（方差分析P〈0.01）,HCa-P/L6和HCa-P的群体倍增时间延长（卡方检验P〈0.01）,Cur对HCa-P/L6的抑制作用大于对HCa-P;细胞周期被重新分布,HCa-P/L6被阻滞在S期,HCa-P被阻滞于S期和G2/M期。[结论]从HCa-P中筛选出了淋巴道高转移细胞系HCa-P/L6。小鼠腹水型肝癌比人肝癌对姜黄素作用敏感,而且高转移细胞株系HCa-P/L6较低转移细胞株HCa-P对Cur更为敏感。HCa-P/L6为肿瘤淋巴道转移机制和中药活性成分筛选的研究提供了一个新的敏感模型。

Effect of vitamin E and human placenta cysteine peptidase inhibitor on expression of cathepsins B and L in implanted hepatoma Morris 5123 tumor model in Wistar rats

AIM: To examine the effectiveness of human placental inhibitors, by injecting vitamin E to rats with transplanted Morris-5123 hepatoma, on the expression of cathepsins B and L in tumor, liver, lung and blood sera after transplantation of Morris 5123 hepatoma. METHODS: Animals were divided into 10 groups receiving three different concentrations of vitamin E and inhibitors along or in combination and compared with negative control (healthy rats) and positive control (tumor rats). Effectiveness of treatment was evaluated with regard to survival time, tumor response and determination of the activities of proteolytic enzymes and their inhibitors using flurogenic substrates. RESULTS: Cathepsins B and L activities were elevated by 16-fold in comparison with negative control tissues, and their endogenous inhibitor activity decreased by 1.2-fold before treatment. In several cases, tumors completely disappeared following vitamin E plus human placental cyteine protease inhibitor (CPI) compared with controls. The number of complete tumor responses was higher when 20 m/kg vitamin E plus 400 μg of CPI was used, i.e. 7/10 rats survived more than two mo. Cathepsins B and L were expressed significantly in tumor, liver, lung tissues and sera in parallel to the increasing of the endogenous inhibitor activity compared with the controls after treatment(P<0.0001) CONCLUSION: The data indicate formation of metastasis significantly reduced in treated rats, which might provide a therapeutic basis for anti-cancer therapy.

胰高血糖素样肽1和肠道菌群（英文）

胃肠道生产20多种肽类激素。其中,胰高血糖素样肽1(GLP-1)在过去的30年里受到最多关注。人们对GLP-1以及另一肠道激素葡萄糖依赖性促胰岛素肽(GIP)功能的研究已导致了两类新的糖尿病治疗药物的开发,分别称为GLP-1R激动剂和DPP-Ⅳ抑制剂。肠道的这些内分泌细胞不是聚集在内分泌腺体中,而是广泛分布在整个胃肠道中,从而与"外部"环境包括食物以及肠道菌群充分接触。本文简要介绍了GLP-1以及营养成分如何调节其分泌,并重点讨论了肠道环境如何影响GLP-1的产生和分泌,包括肠道菌群的贡献。

The dehydration dynamics of a model cell membrane induced by cholesterol analogue 6-ketocholestanol investigated using sum frequency generation vibrational spectroscopy

Dehydration of a surface is the first step for the interaction between biomolecules and the surface. In this study, we systemati- cally investigated the influence of cholesterol analog 6-ketocholestanol （6-KC） on the dehydration of model cell membrane, using sum frequency generation vibrational spectroscopy. In pure DI water environment, two separate dehydration dynamic components were observed in neutrally charged and isotopically labeled 1,2-dimyristoyl-sn-glycero-3-phosphocholine （DMPC） and positively charged 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine（chloride salt） （DMEPC） bilayer： a large-amplitude fast component and a small-amplitude slow component, which originated from the water molecules with a weak and a strong water-membrane bound strengths, respectively. Dehydration of a negatively charged mixed DMPC/DMPG bilayer lead to the membrane-bound water being reorganized to ordered structures quickly. It is evident that the water-membrane bound strengths depend largely on the charge status of the lipid and has an order of neutrally charged membrane〈〈positively charged mem- brane〈〈negatively charged membrane. In an ionic environment, KC1 solution can not only dehydrate DMPC bilayer, but also prevent the 6-KC fiom further dehydrating this model cell membrane. We observed that the dehydration dynamics behavior of DMPC bilayer in the presence of the chaotropic anions is similar to that of the negatively charged DMPG bilayer because of the penetration of chaotropic anions into the DMPC bilayer. The degree of dehydration difficulty in kosmotropic anions fol- lows a Hofmeister series and linearly correlates with the hydration Gibbs free energy of the anions. Our results provide a molecular basis for the interpretation of the Hofmeister effect of kosmotropic anions on ion transport proteins.