EGF and TGF-alpha, the ligands of hyperproduced EGFR in human esophageal carcinoma cells, act as autocrine growth factors

• Published in: International journal of cancer Vol. 45; no. 1; p. 131
• Main Authors: Yoshida, K, Kyo, E, Tsuda, T, Tsujino, T, Ito, M, Niimoto, M, Tahara, E
• Format: Journal Article
• Language: English
• Published: United States 15.01.1990
• Subjects: Adenocarcinoma - analysis; Adenocarcinoma - genetics; Antibodies, Monoclonal; Blotting, Northern; Blotting, Southern; Carcinoma, Squamous Cell - analysis; Carcinoma, Squamous Cell - genetics; Cell Line; DNA Probes; DNA, Neoplasm - analysis; DNA, Neoplasm - genetics; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor - analysis; Epidermal Growth Factor - genetics; ErbB Receptors - analysis; ErbB Receptors - genetics; Esophageal Neoplasms - analysis; Esophageal Neoplasms - genetics; Gene Expression Regulation, Neoplastic - genetics; Humans; Radioligand Assay; RNA, Messenger - analysis; RNA, Messenger - genetics; RNA, Neoplasm - analysis; RNA, Neoplasm - genetics; Transforming Growth Factors - analysis; Transforming Growth Factors - genetics; Tumor Cells, Cultured
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910450124

In order to ascertain autocrine growth factors in esophageal carcinomas, we analysed expression of mRNAs and proteins for epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) in 6 esophageal carcinoma cell lines. Gene alterations were also examined. All of the esophageal carcinoma cell lines expressed mRNA for EGFR and TGF-alpha genes. Interestingly, EGF mRNA of about 5.0 kb was also detected in TE-1, TE-2, and TE-8 cells. Production of protein was also confirmed by binding assay and ELISA on 3 of the 6 cell lines. The cells had a relatively high number of EGFRs and produced TGF-alpha and EGF protein at the same time. Furthermore, anti-EGF (KEM-10) and anti-TGF-alpha (WA-3) monoclonal antibodies (MAbs) inhibited spontaneous uptake of tritiated thymidine (3H-TdR) by TE-1 cells which expressed EGF, TGF-alpha and EGFR mRNA and protein. These results strongly suggest that EGF and/or TGF-alpha produced by carcinoma cells function as autocrine growth factors for human esophageal carcinomas.