ADP-ribosylation Factor 1 Controls the Activation of the Phosphatidylinositol 3-Kinase Pathway to Regulate Epidermal Growth Factor-dependent Growth and Migration of Breast Cancer Cells

Pierre-Luc Boulay,Audrey Claing,Paul Melançon,Mathieu Cotton

doi:10.1074/jbc.m803603200

Pierre-Luc Boulay, Audrey Claing + Show 2 more

Open Access

https://doi.org/10.1074/jbc.m803603200

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Abstract

Activation of intracellular signaling pathways by growth factors is one of the major causes of cancer development and progression. Recent studies have demonstrated that monomeric G proteins of the Ras family are key regulators of cell proliferation, migration, and invasion. Using an invasive breast cancer cell lines, we demonstrate that the ADP-ribosylation factor 1 (ARF1), a small GTPase classically associated with the Golgi, is an important regulator of the biological effects induced by epidermal growth factor. Here, we show that this ARF isoform is activated following epidermal growth factor stimulation and that, in MDA-MB-231 cells, ARF1 is found in dynamic plasma membrane ruffles. Inhibition of endogenous ARF1 expression results in the inhibition of breast cancer cell migration and proliferation. The underlying mechanism involves the activation of the phosphatidylinositol 3-kinase pathway. Our data demonstrate that depletion of ARF1 markedly impairs the recruitment of the phosphatidylinositol 3-kinase catalytic subunit (p110alpha) to the plasma membrane, and the association of the regulatory subunit (p85alpha) to the activated receptor. These results uncover a novel molecular mechanism by which ARF1 regulates breast cancer cell growth and invasion during cancer progression.

Highlights

Receptor tyrosine kinases (RTKs) that comprises four structurally related receptors, namely, the epidermal growth factor receptor (EGFR) (HER-1 and HerB1), HER-2 (ErbB2 or Neu), HER-3/ErbB3, and HER-4/ErbB4 [6]
EGF Stimulation Promotes the Transient Activation of ADP-ribosylation factor 1 (ARF1) and ARF6—To determine whether stimulation of endogenously expressed EGFR led to the activation of ARF1 and/or ARF6 in invasive breast cancer cells, we first examined levels of EGF 0 0.5 1
ARF1 and ARF6 Are Both Localized to the Plasma Membrane of MDA-MB-231 Cells—We examined the cellular distribution of ARF1 and ARF6

Summary

Introduction

Receptor tyrosine kinases (RTKs) that comprises four structurally related receptors, namely, the EGFR (HER-1 and HerB1), HER-2 (ErbB2 or Neu), HER-3/ErbB3, and HER-4/ErbB4 [6]. To further support the role of ARF1 in regulating the PI3K/ Akt pathway, we examined the effect of overexpressing the ARF1 receptors using a specific EGFR antibody. Our data show that depletion of ARF6 had no effect on Akt phosphorylation while it markedly reduced the ability of the EGFR to promote the activation of Erk1/2 (supplemental Fig. S3B).

Results

Conclusion