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11.
Purpose To determine whether ultraviolet (UV) radiation can modulate expression and regulation of matrix metalloproteinases (MMP) in the canine cornea and to examine the expression of MMPs in canine chronic superficial keratitis (CSK). Methods Immunohistochemistry for MMP‐2 and MMP‐9 was performed on samples of CSK. In vitro, canine corneal epithelial cell (CEC) and stromal cell cultures were exposed to UV‐irradiation. Following 2, 8 or 24 h, cells were harvested. MMP expression was examined by zymography, and RT‐PCR was used to examine expression of Slug and Snail. CEC cultures treated with an EGFR inhibitor or a p38 inhibitor were UV‐exposed and harvested 24 h later to examine expression of MMPs, Slug and Snail. Results Canine CSK had increased immunopositivity for both MMP‐2 and MMP‐9 compared to normal canine corneas. In vitro, CEC and stromal cell cultures exposed to UV showed generally increased expression of MMP‐2, ‐9, Slug, and Snail; this response was dose and time dependent. Inhibition of the EGFR pathway did not prevent increased expression of MMP‐2, ‐9, Slug or Snail in UV‐exposed CEC; however, p38 inhibition did attenuate UV induction. Conclusions We have found increased expression of MMPs in clinical samples of CSK compared to normal corneas. In addition, we have shown that there is a temporal association and dose dependency between UV exposure and production of MMPs, Slug, and Snail. These findings suggest that overexpression of MMPs due to UV‐exposure may be linked to changes in the cornea that allow an influx of inflammatory cells and vascularization. 相似文献
12.
目的探讨胃黏膜表皮生长因子(epidermal growth factor,EGF)及其受体(epidermal growthfactor receptor,EGFR)、转化生长因子-α(transforming growth factor-alpha,TGF-α)在大鼠胃溃疡愈合中的变化及意义。方法胃前壁黏膜下注射冰乙酸制备大鼠胃溃疡模型,免疫组织化学法检测溃疡组(42只)和正常组(6只)大鼠胃黏膜EGF、EGFR、TGF-α的表达,测量各指标的积分光密度值。结果 EGF、TGF-α以胞浆表达为主,EGFR以胞膜表达为主,三者均可见壁细胞、内分泌细胞阳性表达,阳性信号以靠近黏膜肌层为主。EGF、EGFR阳性细胞在溃疡术后1d即有增多(P<0.05或P<0.01),TGF-α于溃疡术后2d增多较为明显(P<0.01),之后均呈渐强趋势,EGFR阳性细胞在溃疡术后6d表达最强,EGF、TGF-α阳性细胞于溃疡术后10d积分光密度值达到高峰,溃疡愈合后期三种指标积分光密度值均有降低,但仍显著高于正常组(P<0.01)。结论大鼠胃溃疡自愈时期胃黏膜能特异性表达内源性EGF、EGFR、TGF-α,三者共同参与了胃溃疡愈合过程。 相似文献
13.
Flavone eupatorin is one of the constituents of Orthosiphon stamineus, a medicinal herb used in folk medicine in South East Asia for treatment of various disorders. In our study, we investigated the antiproliferative properties of a chloroform extract of the leaves of O. stamineus and of pure eupatorin. The compound was able to reduce the number of viable cancer cells to the same extent as the extract, with IC(50) values in micromolar range. Moreover, both the eupatorin standard and the extract caused cells to arrest in the G2/M phase of the cell cycle. This clearly demonstrates that eupatorin contributes significantly to the overall extract activity. Induction of mitotic catastrophe, accompanied by key molecular events defining apoptosis, is the mechanism of eupatorin-induced cell death. Importantly, eupatorin (at the doses cytotoxic to cancer cells) did not kill normal cells; it only limited migration of HUVEC endothelial cells and their ability to create tubes. The ability of eupatorin to nonspecifically inhibit many protein kinases was proven and is the probable cause of its cellular effects. In summary, eupatorin emerges as a promising agent in anticancer research. 相似文献
14.
表皮生长因子受体是雌性生殖功能的关键因子,本研究旨在分析表皮生长因子受体基因(epidermal growth factor receptor,EGFR)的多态性与山羊繁殖性能之间的关系.参考牛的EGFR基因序列设计14对引物,采用聚合酶链式反应-单链构象多态性(PCR-SSCP)技术检测在西南地区具有代表性的10个山羊(Cap ra hircus)品种(马头山羊、波尔山羊、古蔺马羊、川东白山羊、大足黑山羊、贵州白山羊、金堂黑山羊、板角山羊、成都麻羊和南江黄羊)中EGFR基因的单核苷酸多态性,并且在贵州白山羊、古蔺马羊和川东白山羊中分析EG FR基因多态性与山羊繁殖力之间的相关性.结果显示,14对引物中有2对引物(P3和P13)的扩增片段出现多态性.对于P3的扩增片段,在不同的山羊品种中检测到AA、AB和BB三种基因型,测序分析表明BB基因型与AA基因型相比有一处单碱基突变(115837C→T).在3个品种中,AA基因型和AB基因型的产羔数最小二乘均值差异不显著(P＞0.05),BB基因型的样本非常有限,没有统计意义;对于P13的扩增片段,在不同的山羊品种中检测到GG、HH和GH型三种基因型,测序分析表明HH基因型与GG基因型相比有一处单碱基突变( 173015 G→A).GG基因型在贵州白山羊和川东白山羊中产羔数最小二乘均值显著高于GH基因型(P＜0.05),而在古蔺马羊样本中只存在GG基因型,HH基因型的样本在三个品种中都很少存在.本研究初步表明,EGFR基因可能是影响山羊产仔数性状的一个主效基因或是与该性状紧密遗传连锁的一个分子遗传标记. 相似文献
15.
Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor that stimulates cell proliferation and survival and becomes dysregulated in a range of solid tumours in man. It is recognized as a key oncogenic driver and has become a favoured therapeutic target and a prognostic and predictive marker of cancer in man. In animals, EGFR dysregulation is emerging as a potential factor in the development of a number of naturally occurring tumours including mammary, lung, glial and epithelial cancers. Comparative analyses suggest that these diseases share many features with equivalent diseases in man and EGFR may have value as a prognostic or a biological marker of animal disease. There is still little direct evidence that EGFR is a critical oncogenic driver in naturally occurring animal disease and there are no veterinary trials of EGFR-targeted therapy. These will be critical steps in establishing a role for EGFR in veterinary oncology. 相似文献
16.
J. K. McCleese M. D. Bear S. K. Kulp C. Mazcko C. Khanna C. A. London 《Veterinary and comparative oncology》2013,11(2):124-139
The receptor tyrosine kinase (RTK) Met is known to be over‐expressed in canine osteosarcoma (OSA). In human cancers, the RTKs Met, epidermal growth factor receptor (EGFR) and Ron are frequently co‐expressed and engage in heterodimerization, altering signal transduction and promoting resistance to targeted therapeutics. We found that EGFR and Ron are expressed in canine OSA cell lines and primary tissues, EGFR and Ron are frequently phosphorylated in OSA tumour samples, and Met is co‐associated with EGFR and Ron in canine OSA cell lines. Transforming growth factor alpha (TGFα) and hepatocyte growth factor (HGF) stimulation induced amplification of ERK1/2 and STAT3 phosphorylation in OSA cells and Met was phosphorylated following TGFα stimulation providing evidence for receptor cross‐talk. Lastly, treatment of OSA cells with combined gefitinib and crizotinib inhibited cell proliferation in an additive manner. Together, these data support the notion that Met, EGFR and Ron interact in OSA cells and as such, may represent viable targets for therapeutic intervention. 相似文献
17.
以快速生长期雄性驯鹿(Rangifer tarandus)鹿茸顶端表皮组织为研究材料,提取其顶端表皮组织总RNA,参考GenBank数据库中牛、羊的表皮生长因子受体(EGFR)基因序列设计同源引物;采用RT-PCR技术、分子克隆技术首次成功获得雄性驯鹿茸顶端表皮组织EGFR基因编码区部分cDNA序列,片段大小为910 bp;Blast比对发现驯鹿EGFR基因与牛、羊、马、人、鲸、野猪的同源性分别是97%、96%、88%、86%、92%、89%,同源性均在85%以上,表明驯鹿EGFR基因在进化上比较保守;构建系统进化树发现驯鹿EGFR基因与牛亲缘关系最近,与人的亲缘关系最远;最后通过在线分析软件预测获得EGFR基因序列对应mRNA最小自由能二级结构。 相似文献
18.
Bergkvist GT Argyle DJ Morrison L MacIntyre N Hayes A Yool DA 《Veterinary and comparative oncology》2011,9(2):106-117
The aims of this study were to establish expression of epidermal growth factor receptor (EGFR) and Ki67 in 67 archived biopsy samples of feline oral squamous cell carcinomas (FOSCCs) and to establish if the expression of either markers was predictive of survival. Samples were immunohistochemically labelled for the two proteins and scored. Statistical analyses of data, including Kaplan-Meier survival curves, were performed. All samples expressed both markers although levels differed between samples. Median overall survival was 46 days and 1-year survival was 5%. There was no correlation between Ki67 and EGFR scores (Pearson's correlation coefficient, P = 0.861). Low cellular proliferation (low Ki67 score) was positively correlated with an overall longer survival (Log Rank, P = 0.02) and a trend towards better survival for the high EGFR group was observed (Log Rank, P = 0.076). Ki67 and EGFR immunostaining in FOSCC may be of value as biochemical markers for screening of biopsies from cases of FOSCC. 相似文献
19.
参考大鼠EGFR基因序列,用RT-PCR方法对SD大鼠EGFR基因cDNA序列进行克隆,获得了SD大鼠EGFR基因的全长4127bp的cDNA序列（GenBank登录号HM801042）,其中CDS长度为3627bp,编码1209个氨基酸。SD大鼠与国外报道的大鼠、小鼠、牛、猴、人等5个物种的EGFR基因cDNA序列的同源性分别为99．5％、92．9％、78．4％、83．4％、80．2％,其编码蛋白的氨基酸序列同源性分别为99．6％、95．9％、86．6％、89．0％、90．5％。这一结果表明了EGFR基N在进化过程中具有较高的保守性。通过比较SD大鼠EGFR基因与GenBank数据库中发布的EGFR基因的cDNA序列,本试验发现了10个SNP位点,其中5个没有改变氨基酸残基的性质,这一研究结果为EGFR基因的SNPs数据库提供了新的信息。 相似文献
20.
S. Sabattini F. R. Mancini L. Marconato B. Bacci F. Rossi M. Vignoli G. Bettini 《Veterinary and comparative oncology》2014,12(3):237-248
This study reports the main clinicopathological features of primary lung cancer (PLC) in 37 dogs, with special regard to the pathogenetic and prognostic role of epidermal growth factor receptor (EGFR) overexpression. For each case the following characteristics were evaluated: tumour‐node‐metastasis (TNM) stage, tumour histotype, histological grade, mitotic activity and immunohistochemical expression of EGFR. In samples with available normal lung tissue, the amount of background anthracosis was also measured by image analysis. In 27 tumours (73%) a variable number of cells (20–100%) stained positively for EGFR. The proportion of EGFR‐positive tumours was significantly higher in cases with background anthracosis, and the amount of anthracosis was correlated with the percentage of positive tumour cells. Additionally, a trend towards shortened survival for the high EGFR group was observed. These findings suggest an involvement of EGFR signalling pathway in canine PLC, a negative prognostic significance of protein overexpression and its potential implication in air pollution carcinogenesis. 相似文献