Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 14, 2005; 11(6): 875-879
Published online Feb 14, 2005. doi: 10.3748/wjg.v11.i6.875
Activation of STAT3 signaling in human stomach adenocarcinoma drug-resistant cell line and its relationship with expression of vascular endothelial growth factor
Li-Fen Yu, Ying Cheng, Min-Min Qiao, Yong-Ping Zhang, Yun-Lin Wu
Li-Fen Yu, Ying Cheng, Min-Min Qiao, Yong-Ping Zhang, Yun-Lin Wu, Department of Gastroenterology, Ruijin Hospital of Shanghai Second Medical University, Shanghai 200025, China
Author contributions: All authors contributed equally to the work.
Supported by Shanghai Education Committee Foundation, No. 024119114
Correspondence to: Dr. Li-Fen Yu, Department of Gastroenterology, Ruijin Hospital of Shanghai Second Medical University, 197 Ruijin er Road, Shanghai 200025, China. graceyu1028@sohu.com
Telephone: +86-21-64370045-665242 Fax: +86-21-64373909
Received: April 9, 2004
Revised: April 11, 2004
Accepted: May 13, 2004
Published online: February 14, 2005
Abstract

AIM: To investigate the difference in activation of STAT3 signaling between two human stomach adenocarcinoma cell lines: 5-fluorouracil resistant cell line and its parental cell line, and to evaluate its relationship with the expression of vascular endothelial growth factor (VEGF).

METHODS: Western blot and electrophoretic mobility shift assay (EMSA) were used to detect the expression of phospho-STAT3 protein and constitutive activation of STAT3 in two human stomach adenocarcinoma cell lines, 5-fluorouracil resistant cell line SGC7901/R and its parental cell line SGC7901, respectively. The mRNA expression of VEGF was analysed by semi-quantitative RT-PCR. The expressive intensity of VEGF protein was measured by immunocytochemistry.

RESULTS: The expressions of phospho-STAT3 protein and constitutive activation of STAT3 between two human stomach adenocarcinoma cell lines were different. Compared with the parental cell line SGC7901, the STAT3-DNA binding activity and the expressive intensity of phospho-STAT3 protein were lower in the drug-resistant cell line SGC7901/R. The expression levels of VEGF mRNA and its encoded protein were also decreased in drug-resistant cell line.

CONCLUSION: Over-expression of VEGF may be correlated with elevated STAT3 activation in parental cell line. Lower VEGF expression may be correlated with decreased STAT3 activation in resistant cell line, which may have resulted from negative feedback regulation of STAT signaling.

Keywords: Stomach adenocarcinoma; Vascular endothelial growth factor; STAT3 protein; Antineoplastic Drug Resistance