Wagner M, Cao T, Lopez M E, Hope C, van Nostrand K, Kobrin M S, Fan H U, Büchler M W, Korc M
Division of Endocrinology, Diabetes and Metabolism, University of California, Irvine 92697, USA.
Int J Cancer. 1996 Dec 11;68(6):782-7. doi: 10.1002/(SICI)1097-0215(19961211)68:6<782::AID-IJC16>3.0.CO;2-2.
Human pancreatic cancers over-express the epidermal growth factor receptor (EGF-R) and all 5 known ligands of the EGF family, including EGF, transforming growth factor-alpha (TGF-alpha), amphiregulin, betacellulin and heparin-binding EGF-like growth factor (HB-EGF). The aim of the present study was to confirm the presence of EGF-R-dependent autocrine loops in a human pancreatic cancer cell line and to explore the possibility that interrupting EGF-R activation by introducing a truncated receptor abrogates pancreatic cancer cell growth. The anchorage-independent growth of PANC-1 human pancreatic cancer cells, previously shown to express TGF-alpha, was inhibited by specific anti TGF-alpha antibodies. PANC-1 cells were then either transfected with an expression plasmid encoding a kinase-deficient EGF-R cDNA (HER653) or infected with the same EGF-R cDNA using a retroviral vector. Multiple transfected and infected clones co-expressed the truncated EGF-R and endogenous EGF-R as revealed by Northern blot analysis and immunoblots. In these clones, there was a marked attenuation in EGF- and TGF-alpha-mediated EGF-R tyrosine phosphorylation and c-fos induction. There was also a significant decrease in colony formation in soft agar by comparison with control cells and a significant increase in the effect of the growth-inhibitory effect of the alkylating agent cisplatinum in these clones. Our observations indicate that dominant negative inhibition of EGF-R may have therapeutic potential in pancreatic cancer.
人类胰腺癌过度表达表皮生长因子受体（EGF-R）以及EGF家族的所有5种已知配体，包括EGF、转化生长因子-α（TGF-α）、双调蛋白、β细胞ulin和肝素结合EGF样生长因子（HB-EGF）。本研究的目的是证实人胰腺癌细胞系中存在EGF-R依赖性自分泌环，并探讨通过引入截短的受体中断EGF-R激活从而消除胰腺癌细胞生长的可能性。先前已证明表达TGF-α的PANC-1人胰腺癌细胞的非锚定依赖性生长受到特异性抗TGF-α抗体的抑制。然后用编码激酶缺陷型EGF-R cDNA（HER653）的表达质粒转染PANC-1细胞，或使用逆转录病毒载体用相同的EGF-R cDNA感染该细胞。Northern印迹分析和免疫印迹显示，多个转染和感染的克隆共表达截短的EGF-R和内源性EGF-R。在这些克隆中，EGF和TGF-α介导的EGF-R酪氨酸磷酸化以及c-fos诱导明显减弱。与对照细胞相比，软琼脂中的集落形成也显著减少，并且在这些克隆中烷化剂顺铂的生长抑制作用显著增强。我们的观察结果表明，EGF-R的显性负性抑制在胰腺癌中可能具有治疗潜力。
