Wang Zhiwei, Sengupta Radha, Banerjee Sanjeev, Li Yiwei, Zhang Yuxiang, Rahman K M Wahidur, Aboukameel Amro, Mohammad Ramzi, Majumdar Adhip P N, Abbruzzese James L, Sarkar Fazlul H
Departments of Pathology and Internal Medicine, Division of Hematology and Oncology, Karmanos Cancer Institute, Wayne State University, 110 East Warren Avenue, Detroit, MI 48201, USA.
Cancer Res. 2006 Aug 1;66(15):7653-60. doi: 10.1158/0008-5472.CAN-06-1019.
The epidermal growth factor receptor (EGFR) signaling network plays critical roles in human cancers, including pancreatic cancer, suggesting that the discovery of specific agents targeting EGFR would be extremely valuable for pancreatic cancer therapy. EGFR-related protein (ERRP), a recently identified pan-erbB inhibitor, has been shown to inhibit growth and induce apoptosis of pancreatic cancer cells in vitro and tumor growth in a xenograft model. However, the precise molecular mechanism(s) by which ERRP exerts its antitumor activity remains unclear. The current investigation was undertaken to delineate the tumor growth inhibitory mechanism(s) of ERRP in pancreatic cancer cells. Using multiple molecular assays, such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, apoptosis, gene transfection, real-time reverse transcription-PCR, Western blotting, invasion, and electrophoretic mobility shift assay for measuring DNA-binding activity of nuclear factor-kappaB (NF-kappaB), we found that ERRP caused marked inhibition of pancreatic cancer cell growth. This was accompanied by increased apoptosis and concomitant attenuation of Notch-1 and NF-kappaB and down-regulation of NF-kappaB downstream genes, such as matrix metalloproteinase-9 and vascular endothelial growth factor, resulting in the inhibition of pancreatic cancer cell invasion through the Matrigel. We also found that down-regulation of Notch-1 by small interfering RNA before ERRP treatment resulted in enhanced cell growth inhibition and apoptosis. Our data suggest that the ERRP-mediated inactivation of EGFR, Notch-1, NF-kappaB, and its downstream target genes contributed to the inhibition of cell growth and invasion. We conclude that ERRP could be an effective agent for inhibiting tumor growth and invasion for the treatment of pancreatic cancer.
表皮生长因子受体（EGFR）信号网络在包括胰腺癌在内的人类癌症中发挥着关键作用，这表明发现靶向EGFR的特异性药物对胰腺癌治疗将具有极高价值。表皮生长因子受体相关蛋白（ERRP）是一种最近鉴定出的泛erbB抑制剂，已被证明在体外可抑制胰腺癌细胞生长并诱导其凋亡，在异种移植模型中可抑制肿瘤生长。然而，ERRP发挥其抗肿瘤活性的确切分子机制仍不清楚。当前的研究旨在阐明ERRP在胰腺癌细胞中的肿瘤生长抑制机制。通过使用多种分子检测方法，如3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐检测、凋亡检测、基因转染、实时逆转录-PCR、蛋白质印迹法、侵袭检测以及用于测量核因子-κB（NF-κB）DNA结合活性的电泳迁移率变动分析，我们发现ERRP可显著抑制胰腺癌细胞生长。这伴随着凋亡增加以及Notch-1和NF-κB的同时减弱，以及NF-κB下游基因如基质金属蛋白酶-9和血管内皮生长因子的下调，从而导致胰腺癌细胞通过基质胶的侵袭受到抑制。我们还发现，在ERRP处理前用小干扰RNA下调Notch-1会增强细胞生长抑制和凋亡。我们的数据表明，ERRP介导的EGFR、Notch-1、NF-κB及其下游靶基因的失活有助于抑制细胞生长和侵袭。我们得出结论，ERRP可能是一种用于抑制肿瘤生长和侵袭以治疗胰腺癌的有效药物。
