Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0154059 (Esophagus)
 2,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidermal growth factor receptor is over-expressed in several tumors and is the target for the tyrosine kinase inhibitor gefitinib. This receptor is also over-expressed in esophageal adenocarcinomas. In non-small cell lung cancer, specific somatic mutations residing in the epidermal growth factor receptor tyrosine kinase in the activation loop and the glycine-rich P-loop, are responsible for an enhanced sensitivity toward gefitinib. We analyzed exons 19 and 21 coding for the receptor tyrosine kinase of the epidermal growth factor gene in 105 samples of esophageal (Barrett's) adenocarcinoma by denaturing high-pressure liquid chromatography. We found only one silent mutation in exon 19 of adenine to guanine in codon 754 leading to a substitution of K to K, the rest of the sample being wild-type genotype. In conclusion, mutations within the tyrosine kinase domain of EGFR associated with sensitivity of non-small cell lung cancer patients to gefitinib are not present in esophageal (Barrett's) adenocarcinoma.
Dis Esophagus 2007
PMID:Lack of EGFR gene mutations in exons 19 and 21 in esophageal (Barrett's) adenocarcinomas. 1722 3

Aberrant methylation of tumor suppressor genes plays an important role in the development of esophageal squamous cell carcinoma (ESCC). The purpose of the present study was to identify the epigenetic changes in ESCC. Methylation-sensitive arbitrarily primed polymerase chain reaction (MS AP-PCR) analysis was used on 22 matched ESCC tumors and adjacent normal tissues. Through this screen we identified a frequently methylated fragment that showed a high homology to the 5'-CpG island of the gene encoding a transmembrane protein containing epidermal growth factor and follistatin domains (TPEF). The methylation status of the TPEF gene was then detected by bisulfite sequencing and the levels of TPEF mRNA were detected by RT-PCR. In addition, the effects of a methylation inhibitor 5-aza-2'-deoxycytidine on TPEF mRNA expression was determined in cells of ESCC cell lines. Hypermethylation of the 5'-CpG island of TPEF was found in 12 of 22 (54.5%) primary tumors. Reverse transcription PCR analysis demonstrated that TPEF mRNA expression was significantly lower in tumors than in adjacent normal tissues, which is associated with promoter hypermethylation. In addition, treatment of ESCC cell lines with 5-aza-2'-deoxycytidine led to re-expression of the TPEF transcript. In conclusion, we observed promoter of TPEF gene is frequently hpermethylated, and is associated with the loss of TPEF mRNA expression in ESCC samples. Promoter hypermethylation of TPEF gene may play a role in the development of ESCC.
Dis Esophagus 2008
PMID:Aberrant promoter methylation of the TPEF gene in esophageal squamous cell carcinoma. 1904 May 36