Expression of epidermal growth factor receptor and CD44 splicing variants sharing exons 6 and 9 on gastric and esophageal carcinomas: a two-color flow-cytometric analysis |
| |
Authors: | Shohei Koyama Tsunehiko Maruyama Shinya Adachi |
| |
Institution: | (1) Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba-City, Ibaraki 305-8575, Japan Tel.: +81298-53-3210 Fax: +298-53-3039, JP;(2) Department of Surgery, Institute of Clinical Medicine, University of Tsukuba, Tsukuba-City, Ibaraki 305-8575, Japan, JP |
| |
Abstract: | Quantitative analysis based on the percentage of positive cells by two-color flow cytometry was used to quantify the surface
expression of epidermal growth factor receptor (EGFR), and exons v6 and v9 of CD44 splice variants on tumor. Almost all patients
with primary gastric and esophageal carcinomas, and benign mucosa of the stomach and esophagus showed usually high levels
of EGFR expression, a mean of approximately 60% of cells being positive. Metastatic gastric carcinoma showed significantly
higher levels of EGFR expression, a mean of 80% of cells being positive. Reduced expression of EGFR was observed in irradiated
esophageal carcinoma. Adenocarcinomas, including primary and metastatic lesions, or cancer cell lines of the stomach revealed
consistently very low or undetectable levels of expression of exon v6 of the CD44 variant (CD44v) protein. However, CD44v
containing exon v9 could be detected in normal gastric epithelium and primary gastric carcinoma as well as in six adenocarcinoma
cell lines. Exon v9 is significantly overexpressed on metastatic adenocarcinoma cells obtained from malignant ascites. On
the other hand, normal squamous epithelium and primary squamous cell carcinoma (SCC) of the esophagus, and two SCC cell lines
showed coexpression of exons v6 and v9 of CD44v. The expression of the CD44v6 molecule was significantly reduced in the irradiated
primary SCC, although CD44v9 expression on the primary SCC remained unchanged after the radiation therapy. These results suggest
that up-regulation of EGFR and CD44v9 molecules on gastric carcinomas, especially metastatic adenocarcinomas, shows tumor
growth and tumor progression. In addition, down-regulation of EGFR and CD44v6 molecules on irradiated esophageal carcinoma
may be involved in the mechanisms suppressing tumor growth and metastatic potential.
Received: 24 June 1998 / Accepted: 1 September 1998 |
| |
Keywords: | Gastric carcinoma Esophageal carcinoma Epidermal growth factor receptor (EGFR) CD44 splicing variant isoforms (CD44v6 CD44v9) Flow cytometry |
本文献已被 PubMed SpringerLink 等数据库收录! |
|