REGULATION OF INTESTINAL EPITHELIAL GROWTH BY EGF FAMILY

表皮生长因子（EGF）和转化 生长因子-α（TGF α）在胃肠道生理学中的作用， 在特定疾病如溃疡病、Menetrier病和 胃肠道肿瘤继续被确定。EGF- 相关肽家族最近已经发展到包括至少5个 成员，包括双调蛋白（AR），肝素结合EGF样 生长因子（HB-EGF）和β细胞素（BTC）。初步数据 本文中报道的以及在体内和体外数据， 其他研究表明，EGF家族中存在广泛的调节作用， 成员 EGF家族的每个成员都是 通过处理多种上皮细胞系诱导。 在 此外，通过同源重组靶向破坏TGF α， 重组导致TGF α功能的替代， 可能是由相关的家庭成员，这样的表型 改动很小。这些意见强调， EGF家族的特点其主要目标是 建议是为了促进了解的机制， EGF家族的整合以及其影响 肠上皮细胞增殖的整合 包括体内和体外技术。提交数据以支持 AR和HB-EGF是一种模型， 肠上皮细胞，它们的诱导是一种 诱导的净增殖信号的重要贡献者 EGF相关肽。 具体目标直接测试此 假设通过分析AR和HB的相对贡献- EGF对肠上皮细胞（RIE-1系）增殖的影响 反义寡核苷酸和中和抗体的应用 具体目标#2和#3代表了一个协调一致的努力，把EGF- 相关肽在体内的功能前景，通过比较 分析它们在小肠和结肠中的分布 使用1）原位杂交和免疫组织化学，2） 病理生理学操作，如禁食/再喂养， 肠切除术和3）转基因小鼠的功能研究， 过表达TGF α和一个新的小鼠品系（egfr/m1 cwr）， EGF受体（EGF receptor）这些研究 应该提高对正常细胞生长控制的理解， 在选定的生理和病理生理情况下， 更全面地了解异常生长的先决条件 肿瘤和其他肠上皮生长障碍。

Important roles for epidermal growth factor (EGF) and transforming growth factor-alpha (TGFalpha) in gastrointestinal physiology and in specific diseases such as ulcer disease, Menetrier's disease and gastrointestinal neoplasia continue to be identified. The EGF- related peptide family recently has grown to include at least 5 members, including amphiregulin (AR), heparin-binding EGF-like growth factor (HB-EGF) and betacellulin (BTC). Preliminary data reported herein as well as in vivo and in vitro data published by others indicate that there is extensive regulation among EGF family members. For example, expression of each EGF family member is induced by treatment of a variety of epithelial cell lines. In addition, targeted disruption of TGFalpha in vivo by homologous recombination results in replacement of TGFalpha function, presumably by related family members, such that phenotypic alterations are minimal. These observations emphasize the integrated nature of the EGF family. The broad objective of this proposal is to advance understanding of the mechanisms of integration within the EGF family and also the implications of integration for intestinal epithelial cell proliferation by using both in vivo and in vitro techniques. Data is submitted in support of a model whereby AR and HB-EGF are immediate-early genes in intestinal epithelial cells and that their induction is an important contributor to the net proliferative signal induced by EGF-related peptides. Specific aim -1 directly tests this hypothesis by analysis of the relative contribution of AR and HB- EGF to intestinal epithelial cell (RIE-1 line) proliferation by the use of antisense oligonucleotides and neutralizing antibodies Specific aims #2 and #3 represent a concerted effort to place EGF- related peptides into functional perspective in vivo by comparative analysis of their distribution in the small intestine and colon using 1) in situ hybridization and immunohistochemistry, 2) pathophysiological manipulations such as fasting/refeeding and bowel resection and 3) functional studies of transgenic mice that over-express TGFalpha and a new mouse line (egfr/m1cwr) with targeted disruption of the EGF receptor (EGFr). These studies should improve understanding of growth control in normal cells and in selected physiological and pathophysiological circumstances, a prerequisite for a more complete understanding of aberrant growth in neoplasia and other disorders of intestinal epithelial growth.