Brief Article
Copyright ©2014 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. May 14, 2014; 20(18): 5511-5518
Published online May 14, 2014. doi: 10.3748/wjg.v20.i18.5511
Proteomic identification of tumor biomarkers associated with primary gallbladder cancer
Hai-Lin Huang, Hou-Shan Yao, Yi Wang, Wei-Jun Wang, Zhi-Qian Hu, Kai-Zhou Jin
Hai-Lin Huang, Department of General Surgery, Hospital of China Armed Police Forces, Nanchang 330030, Jiangxi Province, China
Hou-Shan Yao, Yi Wang, Wei-Jun Wang, Zhi-Qian Hu, Kai-Zhou Jin, Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai 200003, China
Author contributions: Huang HL and Yao HS contributed equally to this work; Huang HL, Yao HS and Hu ZQ designed the research; Huang HL, Yao HS, Jin KZ and Wang WJ performed the research; Huang HL and Yao HS provided new reagents/analytic tools; Huang HL analyzed the data; Huang HL, Yao HS, Wang Y and Hu ZQ wrote the paper.
Correspondence to: Zhi-Qian Hu, MD, Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, 415 Feng Yang Road, Shanghai 200003, China. hzqcyto@126.com
Telephone: +86-21-81885591 Fax: +86-21-81885591
Received: October 30, 2013
Revised: January 22, 2014
Accepted: February 17, 2014
Published online: May 14, 2014
Abstract

AIM: To identify potential biomarkers of primary gallbladder cancer (PGC).

METHODS: Fresh PGC, cholecystitis and normal gallbladder tissue specimens collected from 10 patients, respectively, were subjected to comparative proteomic analysis. The proteomic patterns of PGC were compared with those of cholecystitis and normal gallbladder tissues using two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins were then identified using a MALDI-TOF mass spectrometer (MS) and database searches. To further validate these proteins, 20 samples of PGC tissues and normal tumor-adjacent tissues were collected for Western blot, quantitative real-time PCR, and immunohistochemical staining assay.

RESULTS: Seven differentially expressed protein spots were detected by 2-ED analysis by comparing the average maps of PGC, cholecystitis and normal gallbladder tissues. Six of the seven differentially expressed proteins were identified using MALDI-TOF MS, with three overexpressed and three underexpressed in PGC tissue. Protein levels of annexin A4 (ANXA4) were significantly elevated, and heat shock protein 90-beta (Hsp90β) and dynein cytoplasmic 1 heavy chain 1 (Dync1h1) were decreased in PGC tissues relative to the normal tumor-adjacent tissues as shown by Western blot analysis. However, levels of actin, aortic smooth muscle and gamma-actin were unchanged. In addition, the mRNA levels of all 5 proteins showed similar changes to those of the protein levels (P < 0.01). Further validation by immunohistochemical analysis showed the upregulated expression of ANXA4 and decreased expression of Hsp90β and Dync1h1 in the cytoplasm of PGC tissues relative to the normal tumor-adjacent tissues.

CONCLUSION: Three proteins are identified as potential biomarkers of PGC using proteomic analysis. The functions of these proteins in the carcinogenesis of PGC remain to be studied.

Keywords: Primary gallbladder cancer, Proteomic analysis, Annexin A4, Dynein cytoplasmic 1 heavy chain 1, Heat shock protein 90-beta, Biomarker

Core tip: A new comparative proteomic study using human primary gallbladder cancer (PGC), cholecystitis and normal gallbladder tissues to identify biomarkers of PGC was performed. Three new potential biomarkers of PGC were validated and may be informative in understanding the carcinogenic mechanisms and monitoring the treatment of PGC.