Rapid induction of heparin-binding epidermal growth factor/diphtheria toxin receptor expression by Raf and Ras oncogenes

• Published in: Genes & development 1995-08, Vol.9 (16), p.1953-1964
• Main Authors: McCarthy, S A, Samuels, M L, Pritchard, C A, Abraham, J A, McMahon, M
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Animals; Base Sequence; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; Cell Line; Cell Line, Transformed; Cell Transformation, Neoplastic; Diphtheria Toxin - pharmacology; DNA Primers; Epidermal Growth Factor - metabolism; Estradiol - pharmacology; Gene Expression - drug effects; Genes, ras; Heparin - metabolism; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; JNK Mitogen-Activated Protein Kinases; Mice; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Oncogene Proteins v-raf; Oncogenes; Polymerase Chain Reaction - methods; Protein-Serine-Threonine Kinases - genetics; Protein-Tyrosine Kinases - genetics; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins c-jun - metabolism; Proto-Oncogene Proteins c-raf; Receptors, Cell Surface - biosynthesis; Retroviridae Proteins, Oncogenic - genetics; RNA, Messenger - analysis; RNA, Messenger - biosynthesis
• ISSN: 0890-9369; 1549-5477
• DOI: 10.1101/gad.9.16.1953

We have used differential display PCR to search for mRNAs induced by delta Raf-1:ER, an estradiol-dependent form of Raf-1 kinase. Through this approach the gene encoding heparin-binding epidermal growth factor (HB-EGF) was identified as an immediate-early transcriptional target of oncogenic Raf kinases. Activation of delta Raf-1:ER and a conditional oncogenic form of B-Raf, delta B-RAF:ER, resulted in rapid and sustained induction of HB-EGF mRNA expression and secretion of mature HB-EGF from cells. Neutralizing anti-HB-EGF antisera prevented the delayed activation of the c-Jun amino-terminal kinases that is observed in cells transformed by delta Raf-1:ER. These results demonstrate that distinct signaling pathways can cross talk via the secretion of polypeptide growth factors. Furthermore, cells transformed by oncogenic Ras, which also induced HB-EGF expression, demonstrated a marked increase in sensitivity to the cytotoxic action of diphtheria toxin, for which the membrane anchored HB-EGF precursor acts as a cell-surface receptor.