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 4

COMMD1 inhibits HIF-mediated transcription and DNA binding without affecting HIF-α expression.

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COMMD1 inhibits HIF-mediated transcription and DNA binding without affec...
(A) Protein expression of HIF-1α and HIF-2α was not affected by COMMD1 deficiency in HT29 and U2OS cells. Western blot analysis for HIF-1α, HIF-2α, COMMD1, and β-Actin from the indicated samples is shown. Long and short exposures of the HIF-1α Western blot are shown. (B) HEK 293T cells with a stable repression of COMMD1 or control cells were cotransfected with 5xHRE-firefly luciferase reporter and renilla luciferase control plasmid. Cells were incubated under normoxia or hypoxia for 16 hours. HRE reporter activity was determined by measuring firefly luciferase in the lysates and was corrected for transfection efficiency using renilla luciferase activities. Results are expressed as fold induction relative to normoxic conditions in shControl cells (mean ± SD of triplicate samples are shown). (C) The same cells examined in B were used for the HIF-1α HRE DNA binding assay. DNA binding is expressed as fold binding relative to normoxic conditions in shControl cells (mean ± SD of triplicate samples are shown). COMMD1 expression is shown by immunoblot analysis. (D–F) HIF1A mRNA expression (encoding for HIF-1α) was determined by qRT-PCR in (D) HT29 and (E) U2OS cells and normalized to shControl transfected cells under normoxia. (F) Similarly, the effect of TNF treatment on HIF1A expression in HT29 was also examined (mean ± SEM of triplicate samples are shown).