Original Research
Copyright ©The Author(s) 2001. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 15, 2001; 7(4): 490-495
Published online Aug 15, 2001. doi: 10.3748/wjg.v7.i4.490
Experimental and clinic-opathologic study on the relationship between transcription factor Egr-1 and esophageal carcinoma
Ming-Yao Wu, Mao-Huai Chen, Ying-Rui Liang, Guo-Zhao Meng, Huan-Xing Yang, Chu-Xiang Zhuang
Ming-Yao Wu, Mao-Huai Chen, Ying-Rui Liang, Guo-Zhao Meng, Huan-Xing Yang, Chu-Xiang Zhuang, Department of Pathology, Shantou University Medical College, Shantou 515031, Guangdong Province, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 39670298.
Correspondence to: Ming-Yao Wu, Department of Pathology, Shantou University Medical College, 22 Xinling Road, Shantou 515031, Guangdong Province, China. mywu@ncrc.stu.edu.cn
Telephone: 0086-754-8900486 Fax: 0086-754-8557562
Received: February 6, 2001
Revised: February 8, 2001
Accepted: February 12, 2001
Published online: August 15, 2001
Abstract

AIM: To observe the growth suppression effect of exogenous introduction of early growth response gene-1 (Egr-1 gene) on esophageal carcinoma tissue as well as on esophageal carcinoma cell line Eca109 and to explore the potential application of Egr-1 gene in gene therapy of tumor.

METHODS: Eukaryotic expression vector of PCMV-Egr-1 plasmid was introduced into Eca109 cell line which expressed no Egr-1 protein originally with lipofectamine transfection method. The introduction and expression of PCMV-Egr-1 plasmid into Eca109 cell line was confirmed by G418 selection culture, PCR amplification of neogene contained in the vector, Western blot analysis and immunocytochemical analysis. The cell growth curve, soft agar colony formation rate and tumorigenicity in SCID mice were examined to demonstrate the growth suppression effect of exogenous Egr-1 gene on Eca109 cell line. The Egr-1 mRNA and Egr-1 protein were also detected in 50 surgical specimens of esophageal carcinoma by in situ hybridization and immunohistochemistry.

RESULTS: Exogenous Egr-1 gene was introduced successfully into Eca109 cell line and expressed Egr-1 protein stably. The transfected Eca109 cell line grew more slowly than control Eca109 as shown by cell growth curves, the soft agar colony formation rate (4.0% vs 6.9%, P < 0.01) and the average growth rate of tumor in SCID mice (35.5 ± 7.6 vs 65.8 ± 7.6, P < 0.05). The expression level of Egr-1 mRNA and protein significantly increased in dysplastic epithelia adjacent to cancer rather than in cancer tissues (65.8% vs 20.0% by ISH and 57.9% vs 14.0% by IHC, P < 0.01).

CONCLUSION: Exogenous Egr-1 gene shows the strong effect of growth inhibition in Eca109 cell line. Egr-1 in the cancer tissue shows down-regulated expression that supports the inhibited function of Egr-1 in cancer growth and suggests Egr-1 may have an important role in gene therapy of esophageal carcinoma.

Keywords: esophageal neoplasms/pathology, tumor cells, cultured, genes, immediate early, gene expression, transfection