Original Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Sep 21, 2011; 17(35): 3986-3993
Published online Sep 21, 2011. doi: 10.3748/wjg.v17.i35.3986
Dynamic changes and surveillance function of prion protein expression in gastric cancer drug resistance
Ji-Heng Wang, Jing-Ping Du, Ying-Hai Zhang, Xiao-Jun Zhao, Ru-Ying Fan, Zhi-Hong Wang, Zi-Tao Wu, Ying Han
Ji-Heng Wang, Jing-Ping Du, Xiao-Jun Zhao, Ru-Ying Fan, Zhi-Hong Wang, Zi-Tao Wu, Ying Han, Department of Gastroenterology, Beijing Army General Hospital, Beijing 100700, China
Ying-Hai Zhang, Department of General Surgery, Jiamusi University Medical College, Jiamusi 154004, Heilongjiang Province, China
Author contributions: Wang JH and Du JP performed the majority of experiments; Wang ZH, Wu ZT provided vital reagents and analytical tools; Zhang YH, Zhao XJ and Fan RY collected the chemotherapy for gastric cancer data and performed follow up work; Han Y designed the study and wrote the manuscript.
Supported by National Natural Science Foundation of China, No. 30672063; China Postdoctoral Science Foundation Funded Project, No. 20080431404; and China Postdoctoral Special Fund, No. 200801038
Correspondence to: Ying Han, MD, Beijing Army General Hospital, No. 5 Nanmengcang Road, Dongcheng district, Beijing 100700, China. ying1000@beihua.edu.cn
Telephone: +86-10-66721168  Fax: +86-10-66721168
Received: February 22, 2011
Revised: May 19, 2011
Accepted: May 26, 2011
Published online: September 21, 2011
Abstract

AIM: To explore the dynamic changes of prion protein (PrPc) in the process of gastric cancer drug resistance and the role of PrPc expression in the prognosis of gastric cancer patients receiving chemotherapy.

METHODS: A series of gastric cancer cell lines resistant to different concentrations of adriamycin was established, and the expression of PrPc, Bcl-2 and Bax was detected in these cells. Apoptosis was determined using Annexin V staining. Western blotting and immunohistochemistry were performed to detect the expression of PrPc in patients receiving chemotherapy and to explore the role of PrPc expression in predicting the chemosensitivity and the outcome of gastric cancer patients receiving chemotherapy. Follow-up was performed for 2 years.

RESULTS: PrPc expression was increased with the increase in drug resistance. Bcl-2, together with PrPc, increased the level of anti-apoptosis of cancer cells. Increased PrPc expression predicted the enhanced level of anti-apoptosis and resistance to anticancer drugs. PrPc expression could be used as a marker for predicting the efficacy of chemotherapy and the prognosis of gastric cancer. Increased PrPc expression predicted both poor chemosensitivity and a low 2-year survival rate. Contrarily, low PrPc expression predicted favorable chemosensitivity and a relatively high 2-year survival rate.

CONCLUSION: PrPc expression is associated with histological types and differentiation of gastric cancer cells; The PrPc expression level might be a valuable marker in predicting the efficacy of chemotherapy and the prognosis of gastric cancer patients receiving chemotherapy.

Keywords: Prion protein; Gastric cancer; Drug resistance; Chemotherapy; Apoptosis