Transcription factor ATF3 links host adaptive response to breast cancer metastasis
Chris C. Wolford, … , Robert L. Sutherland, Tsonwin Hai
Chris C. Wolford, … , Robert L. Sutherland, Tsonwin Hai
Published June 10, 2013
Citation Information: J Clin Invest. 2013;123(7):2893-2906. https://doi.org/10.1172/JCI64410.
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Research Article Oncology

Transcription factor ATF3 links host adaptive response to breast cancer metastasis

Abstract

Host response to cancer signals has emerged as a key factor in cancer development; however, the underlying molecular mechanism is not well understood. In this report, we demonstrate that activating transcription factor 3 (ATF3), a hub of the cellular adaptive response network, plays an important role in host cells to enhance breast cancer metastasis. Immunohistochemical analysis of patient tumor samples revealed that expression of ATF3 in stromal mononuclear cells, but not cancer epithelial cells, is correlated with worse clinical outcomes and is an independent predictor for breast cancer death. This finding was corroborated by data from mouse models showing less efficient breast cancer metastasis in Atf3-deficient mice than in WT mice. Further, mice with myeloid cell–selective KO of Atf3 showed fewer lung metastases, indicating that host ATF3 facilitates metastasis, at least in part, by its function in macrophage/myeloid cells. Gene profiling analyses of macrophages from mouse tumors identified an ATF3-regulated gene signature that could distinguish human tumor stroma from distant stroma and could predict clinical outcomes, lending credence to our mouse models. In conclusion, we identified ATF3 as a regulator in myeloid cells that enhances breast cancer metastasis and has predictive value for clinical outcomes.

Authors

Chris C. Wolford, Stephen J. McConoughey, Swati P. Jalgaonkar, Marino Leon, Anand S. Merchant, Johnna L. Dominick, Xin Yin, Yiseok Chang, Erik J. Zmuda, Sandra A. O’Toole, Ewan K.A. Millar, Stephanie L. Roller, Charles L. Shapiro, Michael C. Ostrowski, Robert L. Sutherland, Tsonwin Hai

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Figure 6

MMP9 plays a role in the ability of ATF3 in macrophages to facilitate invasiveness in vitro.

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MMP9 plays a role in the ability of ATF3 in macrophages to facilitate in...
(A) Left: 3D structures of MCF10A cells were cocultured without (–) or with WT or KO bone marrow–derived macrophages. Percent 3D structures with invasion was scored as in Methods (3 experiments). *P < 0.05, Mann-Whitney test. Right: Phase-contrast (top) and immunofluorescent (bottom) images. Green, laminin V (basement membrane); blue, Topro-3 (nuclei). Arrows denote basement membrane disruption. (B) Same as A, but macrophages were transduced with retrovirus expressing ATF3 or control (Venus). (C) Same as A, but macrophages were treated with MMP9 inhibitor (MMP9-i) or with vehicle (V). (D) Raw264.7 macrophage cells expressing vector or ATF3 were analyzed for Mmp9 by RT-qPCR (left) or zymogram (right). The standardized Mmp9 mRNA signal (against tubulin) from vector-expressing cells was defined as 1. (E) Same as D, but percent 3D structures with invasion was scored (from 3 experiments). *P < 0.05, Mann-Whitney test. (F) Left: Same as D, but ATF3-expressing Raw cells were used and transfected with Mmp9 or control siRNA before coculture with the 3D structures. Right: Knockdown efficiency was tested by RT-qPCR. (G) ChIP analysis using IgG control or ATF3 antibody for Mmp9 promoter in Raw cells (representative from 3 experiments). *P < 0.05, Student’s t test. (H) Same as G, but primary macrophages were used (left, qPCR; right, gel). Scale bars: 50 μm (A).