安胃汤对胃溃疡大鼠溃疡修复及表皮生长因子的影响

目的 探讨安胃汤对实验性乙酸大鼠胃溃疡模型的作用机制.方法 采用放射免疫方法和免疫组织化学方法观察安胃汤对实验性乙酸大鼠胃溃疡模型愈合时血清EGF和胃黏膜EGF表达的影响,对后者进行图像分析及统计学处理.结果 与模型组相比,安胃汤治疗组和雷尼替丁组可提高血清表皮生长因子,差异具有统计学意义(P<0.01),安胃汤大剂量组与雷尼替丁组相比差异有统计学意义(P<0.05);与模型组相比,安胃汤治疗组和雷尼替丁组可显著增强胃黏膜EGF,差异具有统计学意义(P<0.01),安胃汤大剂量组强于雷尼替丁组,差异具有统计学意义(P<0.01).结论 安胃汤可能通过提高血清EGF和增强胃黏膜EGF表达,而促进溃疡愈合、提高溃疡愈合的质量.     

表皮生长因子在小鼠肾脏远端小管发育中的表达

目的观察表皮生长因子（EGF）在小鼠肾脏远端小管发育中的表达，探讨其在小鼠肾脏远端小管发育中的作用。方法采用免疫组化、免疫荧光、Western blot技术结合体视学分析方法检测生后1、3、5、6、7、14、21、28和40天小鼠肾脏远端小管EGF的表达特征。结果EGF于生后6d开始出现在肾皮、髓质交界处的远直小管上皮细胞，之后随着日龄的增加其表达量逐渐增加，表达于皮、髓质远直小管，21天同成年鼠表达于远直小管和远曲小管第一段。结论EGF对小鼠肾脏远端小管的分化、生长发育起重要作用。     

EGCG inhibits activation of the insulin-like growth factor (IGF)/IGF-1 receptor axis in human hepatocellular carcinoma cells

The receptor tyrosine kinase (RTK) insulin like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis plays an important role in the development of hepatocellular carcinoma (HCC). EGCG inhibits activation of the various types of RTKs and that this is associated with inhibition of multiple downstream signaling pathways. In this study we examined the effects of EGCG on activity of the IGF/IGF-1R axis in HepG2 human HCC cells which express constitutive activation of this axis. The level of phosphorylated (i.e. activated) form of the IGF-1R protein (p-IGF-1R) was increased in a series of human HCC cell lines when compared with the Hc normal human hepatocytes. EGCG preferentially inhibited growth of HepG2 cells when compared with Hc cells. Treatment of HepG2 cells with EGCG induced apoptosis and caused a decrease in the p-IGF-1R protein and its downstream signaling molecules including the p-ERK, p-Akt, p-Stat-3, and p-GSK-3β proteins, both in the absence or presence of ligand stimulation. EGCG also decreased the levels of both IGF-1 and IGF-2 proteins and mRNAs, but increased the levels of the IGFBP-3 protein. These findings suggest that EGCG can overcome the stimulatory effects of IGFs on the IGF-1R dependent signaling pathway, thus expanding the roles of EGCG as an inhibitor of critical RTKs involved in HCC cell proliferation. These results provide further evidence that EGCG may be useful in the chemoprevention or treatment of liver cancer.     

EGF-IL-18 fusion protein as a potential anti-tumor reagent by induction of immune response and apoptosis in cancer cells

We report here the generation and characterization of EGF-IL-18 fusion protein as an anti-tumor reagent. The epidermal growth factor (EGF) and interleukin-18 (IL-18) fusion protein was shown to induce interferon-γ (IFNγ) expression and secretion in KG-1 cells, and to promote PBMNC proliferation. It also stimulated activation of CD4⁺ T cells, and increased other immune responses. Moreover, EGF-IL-18 could induce significant tumor regression in SMMC-7721-xenografted Balb/c nude mice when administered together with peritumoral injection of X-ray-irradiated NK-92 cells, and this regression is associated with arresting of the tumor cells in G1 phase and induction of apoptosis.     

应用bFGF与EGF促进皮肤扩张的临床研究

目的:探索碱性成纤维细胞生长因子(bFGF)和表皮生长因子(EGF)在扩张术中的临床应用方法与效果.方法:27例患者共埋置62个扩张器,随机分为治疗组和对照组,采用自身对照.治疗组在常规扩张的同时于扩张器周围注入bFGF与EGF,对照组仅常规扩张.测量两组扩张率、即时回缩率并进行统计学处理.结果:治疗组的扩张至额定容量的时间、即时回缩率较对照组减少(P＜0.05),扩张率较对照组明显增加(P＜0.01).结论:bFGF与EGF能够促进扩张,降低皮瓣回缩率,提高皮瓣质量,改善治疗效果.     

小鼠肝细胞胰岛素与EGF信号转导磷蛋白质组的动力学行为对比分析

目的分析小鼠肝细胞内胰岛素与表皮生长因子（EGF）信号转导磷蛋白质组的动力学行为差别，以此找出两者关键性的信号蛋白。方法采用双向电泳及放射性同位素标记技术，进行分析比较EGF与胰岛素分别介导的磷酸化蛋白质组的动力学行为。结果参与两者信号转导的磷蛋白质种类没有多大差异，大多数信号磷蛋白磷酸化水平的动力学行为也表现为一致性，但有4个蛋白点其磷酸化水平随时间变化趋势明显不同。结论胰岛素与EGF虽然在多方面有许多相似之处，但在同一细胞内参与信号转导的个别信号蛋白其磷酸化水平的动力学行为差别较大，估计这些蛋白就是导致EGF与胰岛素最终生物学活性有所不同的关键蛋白。     

Presence of epidermal growth factor (EGF) receptor and proliferative response to EGF in six human ovarian carcinoma cell lines

Abstract. Scambia G, Benedetti Panici P, Battaglia F, Ferrandina G, Gaggini C, Mancuso S. Presence of epidermal growth factor (EGF) receptor and proliferative response to EGF in six human ovarian carcinoma cell lines. Int J Gynecol Cancer 1991; 1 : 253–258.
We investigated the role of the EGF-EGFR system as a regulator of ovarian cancer cell growth. In five (OVCA 433, OV 166, OV 1225, OV RS 1000, JA1) of six ovarian cancer cell lines examined we showed the presence of a single high-affinity ¹²⁵I-EGF binding site with Kd varying from 0.24 to 0.86 nM and a number of binding sites/cell from 9700 to 75 000. In OVCA 433, OV 166, and OV RS 1000 cells we demonstrated a low-affinity ¹²⁵I-EGF binding site with Kd ranging from 1.10 to 2.12 nM.
TR-170 cells lacked the EGF binding and were unresponsive to EGF in terms of cell proliferation while all EGFR+ cells except JA 1 exhibited a proliferative response to EGF. Moreover, the growth response of the four EGF-sensitive cell lines showed different patterns since at high EGF concentrations (100 ng ml⁻¹) there was no longer a stimulatory effect in OV 1225, OV 166, and OV RS 1000 cells while the mitogenic activity was still present in OVCA 433 cells.
Our results demonstrate that EGF plays a role in regulating ovarian cancer cell growth. However, the presence of EGFR is not a perfect indicator of the EGFR system functionality. The cell lines we have examined could be useful models to clarify the mechanism of EGF action and the role played by the EGF system in the onset and spread of ovarian tumors.     

Hormonal regulation of endometriotic cell growth in primary cell culture system

Summary A primary cell culture of endometriotic cells was established to examine the hormonal regulation of endometriosis. The addition of estradiol had no effect on the DNA synthesis of cultured endometriotic cells. Progesterone at 10⁻⁷ M caused a significant reduction in the amount of the DNA synthesis. An inhibitory effect of progesterone was completely eliminated by the concomitant addition of RU486, an antiprogesterone. The addition of epidermal growth factor (EGF) at 1 ng/ml significantly increased the DNA synthesis. Other growth factors, such as fibroblast growth factor and insulin-like growth factor also produced a modest but significant increase in DNA synthesis. These results seem to provide clues for clarifying the pathophysiology of endometriosis.     

Heterodimerization and functional interaction between EGF receptor family members: a new signaling paradigm with implications for breast cancer research

Summary The EGF receptor (EGFR) and HER2 are members of a growth factor receptor family. Overexpression of either protein in advanced breast cancer correlates with poor prognosis. EGF stimulates growth by binding to EGFR, activating the receptor's intracellular tyrosine kinase. The initial consequence is phosphorylation of specific tyrosine-containing sequences in the receptor's carboxyl terminus. These phosphotyrosines serve as high affinity recognition sites for proteins that, in turn, transmit the growth signal inside the cell. Mechanistic studies suggest that EGF binds to a single EGFR, triggering dimerization with another like receptor molecule. This dimerization is thought to initiate the tyrosine kinase activation.The EGF receptor family was recently expanded with the sequencing of HER3 and HER4. Each of the four family members was postulated to regulate a unique growth or differentiation signaling repertoire when activated by a receptor-specific ligand. However, new data from numerous laboratories suggest that EGFR family members may play a complex and ultimately more flexible role in signaling by forming heterodimers between family members, e.g. EGFR:HER2 or HER4:HER2. These heterodimers may form even when only one member of the pair binds its ligand.This review summarizes current work on heterodimerization and attempts to predict the consequences for downstream signaling. In brief, when compared to ligand-dependent receptor homodimers comprised of two proteins with the same internalization sequence and phosphorylated tyrosine residues, heterodimers are likely to: i) expand substrate selection and downstream signaling pathway activation; ii) promote interaction between sets of substrates in the mixed receptor complexes that would not ordinarily be physically juxtaposed; iii) alter the duration of receptor signaling by changing rates of receptor internalization, ligand loss, kinase inactivation, recycling, etc.; and iv) alter rates of receptor and substrate dephosphorylation. In addition to understanding interactions of heterodimers with the internalization machinery, identification of receptor-specific substrates and binding proteins for each EGFR family member will be necessary to explicate the role of heterodimers in growth and differentiation.