Esophageal Cancer
Copyright ©The Author(s) 2004. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 15, 2004; 10(12): 1716-1721
Published online Jun 15, 2004. doi: 10.3748/wjg.v10.i12.1716
Differential gene expression between squamous cell carcinoma of esophageus and its normal epithelium; altered pattern of mal, akr1c2, and rab11a expression
Sakineh Kazemi-Noureini, Sergio Colonna-Romano, Abed-Ali Ziaee, Mohammad-Ali Malboobi, Mansour Yazdanbod, Parviz Setayeshgar, Bruno Maresca
Sakineh Kazemi-Noureini, Abed-Ali Ziaee, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; PO Box: 13145-1384
Sergio Colonna-Romano, International Institute of Genetics and Biophysics, National Research Council, Via Marconi 12, 80125 Naples, Italy
Mohammad-Ali Malboobi, National Research Center for Genetic Engineering and Biotechnology (NRCGEB), Tehran, Iran
Mansour Yazdanbod, Shariati Hospital, Department of Surgery, Medical University of Tehran, Tehran, Iran
Parviz Setayeshgar, Pathology department, Madaen Hospital, Tehran, Iran
Bruno Maresca, International Institute of Genetics and Biophysics, National Research Council, Via Marconi 12, 80125 Naples, Italy; and University of Salerno, School of Pharmacy, Dept. Pharmaceutical Sciences, Fisciano, Salerno, Italy
Author contributions: All authors contributed equally to the work.
Correspondence to: Associate Professor Abed-Ali Ziaee (Ph.D.), Institute of Biochemistry and Biophysics,University of Tehran, PO Box: 13145-1384, Tehran, Iran. aa_ziaee@yahoo.uk.co
Telephone: +98-21-6956975 Fax: +98-21-6404680
Received: August 23, 2003
Revised: November 23, 2003
Accepted: December 1, 2003
Published online: June 15, 2004
Abstract

AIM: To identify the altered gene expression patterns in squamous cell carcinoma of esophagus (ESCC) in relation to adjacent normal esophageal epithelium.

METHODS: Total RNA was extracted using SV total RNA isolation kit from snap frozen tissues of ESCC samples and normal esophageal epithelium far from the tumor. Radio-labeled cDNA were synthesized from equal quantities of total RNAs of tumor and normal tissues using combinations of 24 arbitrary 13-mer primers and three different anchoring oligo-dT primers and separated on sequencing gels. cDNA with considerable different amounts of signals in tumor and normal tissue were reamplified and cloned. Using southern blot, the clones of each band were controlled for false positive results caused by probable heterogeneity of cDNA population with the same size. Clones that confirmed differential expression by slot blot selected for sequencing and northern analysis. Corresponding full-length gene sequences was predicted using human genome project data, related transcripts were translated and used for various protein/motif searches to speculate their probable functions.

RESULTS: The 97 genes showed different levels of cDNA in tumor and normal tissues of esophagus. The expression of mal gene was remarkably down regulated in all 10 surveyed tumor tissues. Akr1c2, a member of the aldo-keto reductase 1C family, which is involved in metabolism of sex hormones and xenobiotics, was up-regulated in 8 out of 10 inspected ESCC samples. Rab11a, RPL7, and RPL28 showed moderate levels of differential expression. Many other cDNAs remained to further studies.

CONCLUSION: The mal gene which is switched-off in all ESCC samples can be considered as a tumor suppressor gene that more studies in its regulation may lead to valuable explanations in ESCC development. Akr1c2 which is up-regulated in ESCC probably plays an important role in tumor development of esophagus and may be proposed as a potential molecular target in ESCC treatments. Differential display technique in spite of many disadvantages is still a valuable technique in gene function exploration studies to find new candidates for improved ones like gene chips.

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