Altered Growth Factor Dependence and Transforming Growth Factor Gene Expression in Transformed Rat Tracheal Epithelial Cells

✍ Scribed by Patrice C. Ferriola; Cheryl Walker; Alice T. Robertson; H. Shelton Earp; David W. Rusnak; Paul Nettesheim

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 867 KB
• Volume: 2
• Category: Article
• ISSN: 0899-1987
• DOI: 10.1002/mc.2940020608

✦ Synopsis

The role of peptide growth factors in neoplastic progression of transformed rat tracheal epithelial (RTE) cells was assessed by examining growth factor requirements and expression o f growth factor and growth factor receptor genes in normal and transformed RTE cells. Neoplastically transformed cell lines showed decreased requirements for bovine pituitary extract, insulin, and epidermal growth factor compared t o normal primary RTE cells. Neoplastic RTE cell lines expressed significantly increased levels of transforming growth factor a (TGFa) RNA and secreted TGFa into the media, sugjesting an autocrine role for this growth factor. Increased levels of TGFa RNA were also observed in the preneoplasticstages o f the same cell lines, indicating that increased TGFa expression is an early event in the multistage process o f neoplastic transformation o f RTE cells. TGFp transcripts were also overexpressed in neoplastically transformed cell lines. Our studies suggest that aberrant expression of growth factors may play an important role in the development and/or maintenance o f the transformed phenotype in RTE cells.