Cell Growth & Differentiation, Vol 7, Issue 5 551-561, Copyright © 1996 by American Association of Cancer Research

ARTICLES

Phosphatidylinositol 3-kinase recruitment by p185erbB-2 and erbB-3 is potently induced by neu differentiation factor/heregulin during mitogenesis and is constitutively elevated in growth factor-independent breast carcinoma cells with c-erbB-2 gene amplification

TG Ram and SP Ethier
Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor 48109-0582, USA.

Amplification and overexpression of the c-erbB-2 gene in 21MT-2 and 21MT-1 human breast carcinoma cells results in progressively elevated levels of constitutively tyrosine-phosphorylated p185erbB-2 and is associated with progressive insulin-like growth factor (IGF) and combined IGF/epidermal growth factor (EGF) independence in culture. In addition, the neu differentiation factor/heregulins (HRGs), a family of ligands that activate p185erbB-2 through direct binding to erbB-3 or erbB-4, are potent mitogens for various nonneoplastic mammary epithelial cells and carcinoma cell lines in the absence of both IGF and EGF in culture. We have investigated the ability of ligand induction with HRGs or the constitutive activation of p185erbB-2 in the 21MT breast carcinoma cells to induced the recruitment of phosphatidylinositol 3-kinase (PI3K) by p185erbB-2 and erbB-3. HRG was found to potently induce the recruitment of the M(r) 85,000 regulatory subunit of PI3K by phosphotyrosine proteins in both nonneoplastic H16N-2 mammary epithelial cells (which express normal c-erbB-2 levels) and in the 21MT-2 and 21MT-1 cell lines, which were all isolated from a single patient with intraductal and invasive ductal carcinoma of the breast and express c-erbB-3 but not c-erbB-4 in culture. The activation of PI3K in these cells was also associated with high-level mitogenic responsiveness to HRG, as well as the IGF/EGF-independent proliferation of the 21MT cell lines in culture. The recruitment of PI3K by phosphotyrosine protein during ligand-induced activation, or that seen constitutively in the 21MT tumor cells, did not involve detectable tyrosine phosphorylation of p85. The HRG-induced recruitment of p85 and the constitutive recruitment of p85 in the 21MT cell lines involved direct association with both p185erbB-2 and erbB-3, although greater levels were recruited directly by erbB-3. Wortmannin, a potent inhibitor of PI3K enzymatic activity, also blocked the autonomous proliferation of the 21MT cells, and this effect was reversible in long-term cultures. These data indicate that PI3K may be an especially important mediator of HRG-induced proliferation in mammary epithelial cells and is involved in the autonomous proliferation of growth factor-independent breast carcinoma cells with c-erbB-2 gene amplification.

This article has been cited by other articles:

				M. Maegawa, K. Takeuchi, E. Funakoshi, K. Kawasaki, K. Nishio, N. Shimizu, and F. Ito Growth Stimulation of Non-Small Cell Lung Cancer Cell Lines by Antibody against Epidermal Growth Factor Receptor Promoting Formation of ErbB2/ErbB3 Heterodimers Mol. Cancer Res., April 1, 2007; 5(4): 393 - 401. [Abstract] [Full Text] [PDF]

				N. J. Hellyer, C. B. Mantilla, E. W. Park, W.-Z. Zhan, and G. C. Sieck Neuregulin-dependent protein synthesis in C2C12 myotubes and rat diaphragm muscle Am J Physiol Cell Physiol, November 1, 2006; 291(5): C1056 - C1061. [Abstract] [Full Text] [PDF]

				G. Sithanandam, G. T. Smith, J. R. Fields, L. W. Fornwald, and L. M. Anderson Alternate Paths from Epidermal Growth Factor Receptor to Akt in Malignant Versus Nontransformed Lung Epithelial Cells: ErbB3 Versus Gab1 Am. J. Respir. Cell Mol. Biol., November 1, 2005; 33(5): 490 - 499. [Abstract] [Full Text] [PDF]

				L A Bazley and W J Gullick The epidermal growth factor receptor family Endocr. Relat. Cancer, July 1, 2005; 12(Supplement_1): S17 - S27. [Abstract] [Full Text] [PDF]

				M. Tan, P. Li, K. S. Klos, J. Lu, K.-H. Lan, Y. Nagata, D. Fang, T. Jing, and D. Yu ErbB2 Promotes Src Synthesis and Stability: Novel Mechanisms of Src Activation That Confer Breast Cancer Metastasis Cancer Res., March 1, 2005; 65(5): 1858 - 1867. [Abstract] [Full Text] [PDF]

				J. G. Jackson, P. St. Clair, M. X. Sliwkowski, and M. G. Brattain Blockade of Epidermal Growth Factor- or Heregulin-Dependent ErbB2 Activation with the Anti-ErbB2 Monoclonal Antibody 2C4 Has Divergent Downstream Signaling and Growth Effects Cancer Res., April 1, 2004; 64(7): 2601 - 2609. [Abstract] [Full Text] [PDF]

				G. Sithanandam, G. T. Smith, A. Masuda, T. Takahashi, L. M. Anderson, and L. W. Fornwald Cell cycle activation in lung adenocarcinoma cells by the ErbB3/phosphatidylinositol 3-kinase/Akt pathway Carcinogenesis, October 1, 2003; 24(10): 1581 - 1592. [Abstract] [Full Text] [PDF]

				T. Abe, K. Terada, H. Wakimoto, R. Inoue, E. Tyminski, R. Bookstein, J. P. Basilion, and E. A. Chiocca PTEN Decreases in Vivo Vascularization of Experimental Gliomas in Spite of Proangiogenic Stimuli Cancer Res., May 1, 2003; 63(9): 2300 - 2305. [Abstract] [Full Text] [PDF]

				K. M. Woods Ignatoski, D. L. Livant, S. Markwart, N. K. Grewal, and S. P. Ethier The Role of Phosphatidylinositol 3'-Kinase and Its Downstream Signals in erbB-2-Mediated Transformation Mol. Cancer Res., May 1, 2003; 1(7): 551 - 560. [Abstract] [Full Text] [PDF]

				C. Kumar-Sinha, K. W. Ignatoski, M. E. Lippman, S. P. Ethier, and A. M. Chinnaiyan Transcriptome Analysis of HER2 Reveals a Molecular Connection to Fatty Acid Synthesis Cancer Res., January 1, 2003; 63(1): 132 - 139. [Abstract] [Full Text] [PDF]

				Z. Suo, B. Risberg, M. G. Karlsson, K. Villman, E. Skovlund, and J. M. Nesland The Expression of EGFR Family Ligands in Breast Carcinomas International Journal of Surgical Pathology, April 1, 2002; 10(2): 91 - 99. [Abstract] [PDF]

				N. J. Hellyer, M.-S. Kim, and J. G. Koland Heregulin-dependent Activation of Phosphoinositide 3-Kinase and Akt via the ErbB2/ErbB3 Co-receptor J. Biol. Chem., November 2, 2001; 276(45): 42153 - 42161. [Abstract] [Full Text] [PDF]

				E. Hintermann, M. Bilban, A. Sharabi, and V. Quaranta Inhibitory Role of {alpha}6{beta}4-associated erbB-2 and Phosphoinositide 3-Kinase in Keratinocyte Haptotactic Migration Dependent on {alpha}3{beta}1 Integrin J. Cell Biol., April 24, 2001; 153(3): 465 - 478. [Abstract] [Full Text] [PDF]

				D. K. Biswas, A. P. Cruz, E. Gansberger, and A. B. Pardee Epidermal growth factor-induced nuclear factor kappa B activation: A major pathway of cell-cycle progression in estrogen-receptor negative breast cancer cells PNAS, July 18, 2000; 97(15): 8542 - 8547. [Abstract] [Full Text] [PDF]

				D. Gambaletta, A. Marchetti, L. Benedetti, A. M. Mercurio, A. Sacchi, and R. Falcioni Cooperative Signaling between alpha 6beta 4 Integrin and ErbB-2 Receptor Is Required to Promote Phosphatidylinositol 3-Kinase-dependent Invasion J. Biol. Chem., March 31, 2000; 275(14): 10604 - 10610. [Abstract] [Full Text] [PDF]

				T. G. Ram, M. E. Schelling, and H. L. Hosick Blocking HER-2/HER-3 Function with a Dominant Negative Form of HER-3 in Cells Stimulated by Heregulin and in Breast Cancer Cells with HER-2 Gene Amplification Cell Growth Differ., March 1, 2000; 11(3): 173 - 183. [Abstract] [Full Text]

				S. J. Keely and K. E. Barrett ErbB2 and ErbB3 Receptors Mediate Inhibition of Calcium-dependent Chloride Secretion in Colonic Epithelial Cells J. Biol. Chem., November 19, 1999; 274(47): 33449 - 33454. [Abstract] [Full Text] [PDF]

				K. M. W. Ignatoski, A. J. LaPointe, E. H. Radany, and S. P. Ethier erbB-2 Overexpression in Human Mammary Epithelial Cells Confers Growth Factor Independence Endocrinology, August 1, 1999; 140(8): 3615 - 3622. [Abstract] [Full Text]

				R. Worthylake, L. K. Opresko, and H. S. Wiley ErbB-2 Amplification Inhibits Down-regulation and Induces Constitutive Activation of Both ErbB-2 and Epidermal Growth Factor Receptors J. Biol. Chem., March 26, 1999; 274(13): 8865 - 8874. [Abstract] [Full Text] [PDF]

				L. Y. W. Bourguignon, H. Zhu, A. Chu, N. Iida, L. Zhang, and M.-C. Hung Interaction between the Adhesion Receptor, CD44, and the Oncogene Product, p185HER2, Promotes Human Ovarian Tumor Cell Activation J. Biol. Chem., October 31, 1997; 272(44): 27913 - 27918. [Abstract] [Full Text] [PDF]