COMMD1 disrupts HIF-1α/β dimerization and inhibits human tumor cell invasion
Bart van de Sluis, … , Marc Vooijs, Ezra Burstein
Bart van de Sluis, … , Marc Vooijs, Ezra Burstein
Published May 10, 2010
Citation Information: J Clin Invest. 2010;120(6):2119-2130. https://doi.org/10.1172/JCI40583.
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Research Article Oncology

COMMD1 disrupts HIF-1α/β dimerization and inhibits human tumor cell invasion

Abstract

The gene encoding COMM domain–containing 1 (COMMD1) is a prototypical member of the COMMD gene family that has been shown to inhibit both NF-κB– and HIF-mediated gene expression. NF-κB and HIF are transcription factors that have been shown to play a role in promoting tumor growth, survival, and invasion. In this study, we demonstrate that COMMD1 expression is frequently suppressed in human cancer and that decreased COMMD1 expression correlates with a more invasive tumor phenotype. We found that direct repression of COMMD1 in human cell lines led to increased tumor invasion in a chick xenograft model, while increased COMMD1 expression in mouse melanoma cells led to decreased lung metastasis in a mouse model. Decreased COMMD1 expression also correlated with increased expression of genes known to promote cancer cell invasiveness, including direct targets of HIF. Mechanistically, our studies show that COMMD1 inhibits HIF-mediated gene expression by binding directly to the amino terminus of HIF-1α, preventing its dimerization with HIF-1β and subsequent DNA binding and transcriptional activation. Altogether, our findings demonstrate a role for COMMD1 in tumor invasion and provide a detailed mechanism of how this factor regulates the HIF pathway in cancer cells.

Authors

Bart van de Sluis, Xicheng Mao, Yali Zhai, Arjan J. Groot, Jeroen F. Vermeulen, Elsken van der Wall, Paul J. van Diest, Marten H. Hofker, Cisca Wijmenga, Leo W. Klomp, Kathleen R. Cho, Eric R. Fearon, Marc Vooijs, Ezra Burstein

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Figure 6

COMMD1 binds directly to the amino terminus of HIF-1α and inhibits HIF-1β dimerization.

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COMMD1 binds directly to the amino terminus of HIF-1α and inhibits HIF-1...
(A) Schematic representation of the domains in HIF-1α. AD, activation domain. (B) HEK 293T cells expressing COMMD1-GST or GST and the indicated truncated fragments of FLAG–HIF-1α were used for GSH precipitations and Western blot analysis as shown. (C) Recombinant COMMD-1-MBP was incubated with immobilized recombinant HIF-1α full-length, HIF-1α fragment (1–300), or uncoated wells. Binding of the proteins was detected by absorbance at 450 nm, as described in the Methods section. Data represent the mean of duplicate experiments. (D) HEK 293T cells were transfected to express COMMD1-HA, FLAG–HIF-1α, or HIF-1β as indicated. HIF-1α was immunoprecipitated using an anti-FLAG antibody, and the resulting samples were subjected to Western blot analysis. (E) HEK 293T cell lysates expressing GST, GST-HIF-1α, or COMMD1 were subjected to GSH precipitations. The amount of coprecipitated endogenous HIF-1β was identified by Western blot analysis. (F and G) Lysates from HEK293 cells transfected with HA–HIF-1α were incubated with the indicated recombinant proteins. (F) Immunoprecipitation of HIF-1α (HA antibody, FLAG antibody as a control) was performed. The amount of HIF-1β recovered was assessed by immunoblotting. (G) The lysates were subsequently mixed with tandem HRE oligonucleotide probes, which were then precipitated and immunoblotted for HIF-1α. 2xHRE represents a control oligonucleotide that was not biotinylated, biotin-2xHRE represents the biotinylated version. FL, COMMD1 full-length; SA, streptavidin.