QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 16, Issue 7, 3117-3127, July 2005

This Article Full Text Full Text (PDF) Supplemental Figures All Versions of this Article: E04-10-0945v1 16/7/3117    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cardone, R. A. Articles by Reshkin, S. J. Search for Related Content PubMed PubMed Citation Articles by Cardone, R. A. Articles by Reshkin, S. J.

Protein Kinase A Gating of a Pseudopodial-located RhoA/ROCK/p38/NHE1 Signal Module Regulates Invasion in Breast Cancer Cell Lines

Rosa A. Cardone ^*, Anna Bagorda ^*, Antonia Bellizzi ^*, Giovanni Busco ^*, Lorenzo Guerra ^*, Angelo Paradiso , Valeria Casavola ^*, Manuela Zaccolo , and Stephan J. Reshkin ^*

^* Department of General and Environmental Physiology, University of Bari, 70126 Bari, Italy; Laboratory of Clinical and Experimental Oncology, Oncology Institute of Bari, 70126 Bari, Italy; and Dulbecco Telethon Institute, Venetian Institute of Molecular Medicine, 35124 Padova, Italy

Submitted October 29, 2004; Revised April 1, 2005; Accepted April 12, 2005
Monitoring Editor: John Cleveland

Metastasis results from a sequence of selective events often involving interactions with elements of the tumor-specific physiological microenvironment. The low-serum component of this microenvironment confers increased motility and invasion in breast cancer cells by activating the Na⁺/H⁺ exchanger isoform 1 (NHE1). The present study was undertaken to characterize the signal transduction mechanisms underlying this serum deprivation-dependent activation of both the NHE1 and the concomitant invasive characteristics such as leading edge pseudopodia development and penetration of matrigel in breast cancer cell lines representing different stages of metastatic progression. Using pharmacological and genetic manipulation together with transport and kinase activity assays, we observe that the activation of the NHE1 and subsequent invasion by serum deprivation in metastatic human breast cells is coordinated by a sequential RhoA/p160ROCK/p38MAPK signaling pathway gated by direct protein kinase A phosphorylation and inhibition of RhoA. Fluorescence resonance energy transfer imaging of RhoA activity and immunofluorescence analysis of phospho-RhoA and NHE1 show that serum deprivation dynamically remodels the cell, forming long, leading edge pseudopodia and that this signal module is preferentially compartmentalized in these leading edge pseudopodia, suggesting a tight topographic relation of the signaling module to an invasion-specific cell structure.

Abbreviations used: FRET, fluorescence resonance energy transfer; GAP, GTPase-activating protein; GEF, guanine nucleotide exchange factor; NHE1, Na⁺/H⁺ exchanger isoform 1.

The online version of this article contains supplemental material at MBC Online (http://www.molbiolcell.org).

Address correspondence to: Stephan J. Reshkin (reshkin{at}biologia.uniba.it).

This article has been cited by other articles:

				L. Schneider, C.-M. Stock, P. Dieterich, B. H. Jensen, L. B. Pedersen, P. Satir, A. Schwab, S. T. Christensen, and S. F. Pedersen The Na+/H+ exchanger NHE1 is required for directional migration stimulated via PDGFR-{alpha} in the primary cilium J. Cell Biol., April 6, 2009; 185(1): 163 - 176. [Abstract] [Full Text] [PDF]

				E. K. Hoffmann, I. H. Lambert, and S. F. Pedersen Physiology of Cell Volume Regulation in Vertebrates Physiol Rev, January 1, 2009; 89(1): 193 - 277. [Abstract] [Full Text] [PDF]

				H. C. Stuart, Z. Jia, A. Messenberg, B. Joshi, T. M. Underhill, H. Moukhles, and I. R. Nabi Localized Rho GTPase Activation Regulates RNA Dynamics and Compartmentalization in Tumor Cell Protrusions J. Biol. Chem., December 12, 2008; 283(50): 34785 - 34795. [Abstract] [Full Text] [PDF]

				F. Leve, W. de Souza, and J. A. Morgado-Diaz A Cross-Link between Protein Kinase A and Rho-Family GTPases Signaling Mediates Cell-Cell Adhesion and Actin Cytoskeleton Organization in Epithelial Cancer Cells J. Pharmacol. Exp. Ther., December 1, 2008; 327(3): 777 - 788. [Abstract] [Full Text] [PDF]

				B. Joshi, S. S. Strugnell, J. G. Goetz, L. D. Kojic, M. E. Cox, O. L. Griffith, S. K. Chan, S. J. Jones, S.-P. Leung, H. Masoudi, et al. Phosphorylated Caveolin-1 Regulates Rho/ROCK-Dependent Focal Adhesion Dynamics and Tumor Cell Migration and Invasion Cancer Res., October 15, 2008; 68(20): 8210 - 8220. [Abstract] [Full Text] [PDF]

				L. Yu, D. A. Quinn, H. G. Garg, and C. A. Hales Deficiency of the NHE1 Gene Prevents Hypoxia-induced Pulmonary Hypertension and Vascular Remodeling Am. J. Respir. Crit. Care Med., June 1, 2008; 177(11): 1276 - 1284. [Abstract] [Full Text] [PDF]

				R. A. Cardone, A. Bellizzi, G. Busco, E. J. Weinman, M. E. Dell'Aquila, V. Casavola, A. Azzariti, A. Mangia, A. Paradiso, and S. J. Reshkin The NHERF1 PDZ2 Domain Regulates PKA-RhoA-p38-mediated NHE1 Activation and Invasion in Breast Tumor Cells Mol. Biol. Cell, May 1, 2007; 18(5): 1768 - 1780. [Abstract] [Full Text] [PDF]

				Z. Jia, L. Barbier, H. Stuart, M. Amraei, S. Pelech, J. W. Dennis, P. Metalnikov, P. O'Donnell, and I. R. Nabi Tumor Cell Pseudopodial Protrusions: LOCALIZED SIGNALING DOMAINS COORDINATING CYTOSKELETON REMODELING, CELL ADHESION, GLYCOLYSIS, RNA TRANSLOCATION, AND PROTEIN TRANSLATION J. Biol. Chem., August 26, 2005; 280(34): 30564 - 30573. [Abstract] [Full Text] [PDF]