Essential role for Rac in heregulin beta1 mitogenic signaling: a mechanism that involves epidermal growth factor receptor and is independent of ErbB4. 2006

Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
Department of Pharmacology, University of Pennsylvania School of Medicine, 816 Biomedical Research Building II/III, 421 Curie Blvd., Philadelphia, PA 19104-6160, USA.

Heregulins are a family of ligands for the ErbB3/ErbB4 receptors that play important roles in breast cancer cell proliferation and tumorigenesis. Limited information is available on the contribution of Rho GTPases to heregulin-mediated signaling. In breast cancer cells, heregulin beta1 (HRG) causes a strong activation of Rac; however, it does so with striking differences in kinetics compared to epidermal growth factor, which signals through ErbB1 (epidermal growth factor receptor [EGFR]). Using specific ErbB receptor inhibitors and depletion of receptors by RNA interference (RNAi), we established that, surprisingly, activation of Rac by HRG is mediated not only by ErbB3 and ErbB2 but also by transactivation of EGFR, and it is independent of ErbB4. Similar receptor requirements are observed for HRG-induced actin cytoskeleton reorganization and mitogenic activity via extracellular signal-regulated kinase (ERK). HRG-induced Rac activation was phosphatidylinositol 3-kinase dependent and Src independent. Furthermore, inactivation of Rac by expression of the Rac GTPase-activating protein beta2-chimerin inhibited HRG-induced ERK activation, mitogenicity, and migration in breast cancer cells. HRG mitogenic activity was also impaired by depletion of Rac1 using RNAi. Our studies established that Rac is a critical mediator of HRG mitogenic signaling in breast cancer cells and highlight additional levels of complexity for ErbB receptor coupling to downstream effectors that control aberrant proliferation and transformation.

UI MeSH Term Description Entries
D009363 Neoplasm Proteins Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm. Proteins, Neoplasm
D001943 Breast Neoplasms Tumors or cancer of the human BREAST. Breast Cancer,Breast Tumors,Cancer of Breast,Breast Carcinoma,Cancer of the Breast,Human Mammary Carcinoma,Malignant Neoplasm of Breast,Malignant Tumor of Breast,Mammary Cancer,Mammary Carcinoma, Human,Mammary Neoplasm, Human,Mammary Neoplasms, Human,Neoplasms, Breast,Tumors, Breast,Breast Carcinomas,Breast Malignant Neoplasm,Breast Malignant Neoplasms,Breast Malignant Tumor,Breast Malignant Tumors,Breast Neoplasm,Breast Tumor,Cancer, Breast,Cancer, Mammary,Cancers, Mammary,Carcinoma, Breast,Carcinoma, Human Mammary,Carcinomas, Breast,Carcinomas, Human Mammary,Human Mammary Carcinomas,Human Mammary Neoplasm,Human Mammary Neoplasms,Mammary Cancers,Mammary Carcinomas, Human,Neoplasm, Breast,Neoplasm, Human Mammary,Neoplasms, Human Mammary,Tumor, Breast
D002465 Cell Movement The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell. Cell Migration,Locomotion, Cell,Migration, Cell,Motility, Cell,Movement, Cell,Cell Locomotion,Cell Motility,Cell Movements,Movements, Cell
D004789 Enzyme Activation Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme. Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D005260 Female Females
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000081082 Phosphoinositide-3 Kinase Inhibitors Agents that inhibit PHOSPHOINOSITIDE-3 KINASE activity. Phosphoinositide-3 Kinase Inhibitor,Inhibitor, Phosphoinositide-3 Kinase,Inhibitors, Phosphoinositide-3 Kinase,Kinase Inhibitor, Phosphoinositide-3,Kinase Inhibitors, Phosphoinositide-3,Phosphoinositide 3 Kinase Inhibitor,Phosphoinositide 3 Kinase Inhibitors
D014407 Tumor Cells, Cultured Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely. Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D047428 Protein Kinase Inhibitors Agents that inhibit PROTEIN KINASES. Protein Kinase Inhibitor,Inhibitor, Protein Kinase,Inhibitors, Protein Kinase,Kinase Inhibitor, Protein,Kinase Inhibitors, Protein
D049109 Cell Proliferation All of the processes involved in increasing CELL NUMBER including CELL DIVISION. Cell Growth in Number,Cellular Proliferation,Cell Multiplication,Cell Number Growth,Growth, Cell Number,Multiplication, Cell,Number Growth, Cell,Proliferation, Cell,Proliferation, Cellular

Related Publications

Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
October 1994, The Journal of biological chemistry,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
July 2012, Science signaling,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
November 2003, Molecular and cellular biology,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
August 2008, Molecular and cellular biology,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
December 2012, Science signaling,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
June 1995, Journal of cellular physiology,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
October 2001, Molecular and cellular biology,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
August 1999, The Journal of cell biology,
Chengfeng Yang, and Ying Liu, and Mark A Lemmon, and Marcelo G Kazanietz
August 2008, Clinical cancer research : an official journal of the American Association for Cancer Research,
Copied contents to your clipboard!