Heregulin‐induced activation of ErbB3 by EGFR tyrosine kinase activity promotes tumor growth and metastasis in melanoma cells

• Published in: International journal of cancer 2008-07, Vol.123 (2), p.340-347
• Main Authors: Ueno, Yoko, Sakurai, Hiroaki, Tsunoda, Satoshi, Choo, Min‐Kyung, Matsuo, Mitsuhiro, Koizumi, Keiichi, Saiki, Ikuo
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Carcinoma, Lewis Lung - metabolism; Carcinoma, Lewis Lung - pathology; Cell Line, Tumor; Cell Proliferation; Dermatology; EGFR; ErbB3; Female; Gene Expression Regulation; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Genes, erbB; heregulin; Immunoblotting; Immunoprecipitation; Liver Neoplasms, Experimental - metabolism; Liver Neoplasms, Experimental - pathology; Male; Mammary Neoplasms, Experimental - metabolism; Mammary Neoplasms, Experimental - pathology; Matrix Metalloproteinase 9 - metabolism; Medical sciences; melanoma; Melanoma, Experimental - metabolism; Melanoma, Experimental - pathology; metastasis; Mice; Neoplasms, Experimental - blood supply; Neoplasms, Experimental - metabolism; Neoplasms, Experimental - pathology; Neovascularization, Pathologic - metabolism; Neuregulin-1 - metabolism; Phosphorylation; Protein-Tyrosine Kinases - metabolism; Receptor, Epidermal Growth Factor - metabolism; Receptor, ErbB-3 - genetics; Receptor, ErbB-3 - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Tumors; Tumors of the skin and soft tissue. Premalignant lesions; Up-Regulation
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.23465

ErbB3 receptor tyrosine kinase has been shown to induce tumor progression in several types of cancer through heterodimerization with ErbB2. However, the role of ErbB3 and its ligand heregulin (HRG) in tumor metastasis remains poorly understood. In the present study, we tried to clarify their contributions to the metastasis of ErbB3‐overexpressing B16‐BL6 melanoma cells. Stimulation with HRG induced phosphorylation of ErbB3 and metastatic properties including MMP‐9 expression, invasion, adhesion and experimental lung metastasis in vivo. These cellular responses were blocked by inhibiting the tyrosine kinase activity of EGFR with PD153035. In addition, phosphorylation of EGFR was rapidly induced by HRG, suggesting that EGFR is a possible heterodimeric counterpart of ErbB3. RNA interference demonstrated that subcutaneous tumor growth and angiogenesis was attenuated by inactivation of ErbB3 in cancer cells. Although experimental pulmonary metastasis was not affected by the knockdown of ErbB3, spontaneous metastasis was, even when primary tumors in the foot pad were amputated at a similar size. These results indicate that HRG‐induced activation of ErbB3 via EGFR promotes tumor growth and metastasis of melanoma cells. © 2008 Wiley‐Liss, Inc.