Epidermal growth factor induces HCCR expression via PI3K/Akt/mTOR signaling in PANC-1 pancreatic cancer cells

BMC Cancer

Research Article

Guoxin Zhang¹  Yang Yang¹  Ruihua Shi¹  Bo Hao¹  Jiakai Jiang²  Zekuan Xu²  Yi Zhang³  Zuhu Huang⁴  Jin W Kim⁵  Zhihong Zhang⁶ 

[1] Department of Gastroenterology, the First Affiliated Hospital of Nanjing Medical University, 210029, Nanjing, China;Department of General Surgery, the First Affiliated Hospital of Nanjing Medical University, 210029, Nanjing, China;Department of General Surgery, the First Affiliated Hospital of Nanjing Medical University, 210029, Nanjing, China;Department of Emergency Surgery, the First Affiliated Hospital of Nanjing University of Chinese Medicine, 210029, Nanjing, China;Department of Infectious Diseases, the First Affiliated Hospital of Nanjing Medical University, 210029, Nanjing, China;Department of Obstetrics & Gynecology, college of Medicine, The Catholic University of Korea, 137-040, Seoul, South Korea;Department of Pathology, the First Affiliated Hospital of Nanjing Medical University, 210029, Nanjing, China;

关键词: Pancreatic Cancer;    Epidermal Growth Factor;    Pancreatic Cancer Cell;    Epidermal Growth Factor Stimulation;    Allred Score;   

DOI  :  10.1186/1471-2407-10-161

 received in 2009-09-13, accepted in 2010-04-27,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundHuman cervical cancer oncoprotein 1 (HCCR-1), reported as a negative regulator of p53, is over-expressed in a variety of human cancers. However, it is yet unknown whether HCCR-1 plays any role in pancreatic cancer development. The aim of this study was to investigate the effect of epidermal growth factor on the expression of HCCR in pancreatic cancer cells, and to explore if PI3K/Akt/mTOR signaling pathway mediated this expression.MethodsA polyclonal antibody against HCCR protein was raised by immunizing Balb/c mice with the purified recombinant protein pMBPc-HCCR. Tissue samples were constructed on a tissue chip, and the expression of HCCR was investigated by immunohistochemistry assay and Western blotting. Pancreatic cell line, PANC-1 cells were stably transfected with plasmids containing sense-HCCR-1 fragment and HCCR siRNA fragment. MTT and transwell assay were used to investigate the proliferation and invasion of stable tansfectants. The specific inhibitor of PI3K and mTOR was used to see if PI3K/mTOR signal transduction was involved in the induction of HCCR gene expression. A Luciferase assay was used to see if Akt can enhance the HCCR promoter activity.ResultsHCCR was up-regulated in pancreatic tumor tissues (mean Allred score 4.51 ± 1.549 vs. 2.87 ± 2.193, P < 0.01), especially with high expression in poorly differentiated pancreatic cancer. The growth of cells decreased in HCCR-1 siRNA transfected cells compared with vector transfectants. The number of invasion cells was significantly lower in HCCR-1 siRNA transfected cells (24.4 ± 9.9) than that in vector transfectants (49.1 ± 15.4). Treatment of PANC-1 cells with epidermal growth factor increased HCCR protein level in a dose- and time-dependent manner. However, application of LY294002 and rapamycin caused a dramatic reduction of epidermal growth factor-induced HCCR expression. Over-expression of exogenous constitutively active Akt increased the HCCR promoter activity; in contrast, dominant negative Akt decreased the promoter activity.ConclusionsEGF-induced HCCR-1 over-expression is mediated by PI3K/AKT/mTOR signaling which plays a pivotal role in pancreatic tumor progression, suggesting that HCCR-1 could be a potential target for cancer therapeutics.

【 授权许可】

Unknown   
© Xu et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.