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A Guide to Production, Crystallization, and Structure Determination of Human IKK1/α
Published on: November 2, 2018
TNFalpha induces HIF-1alpha expression through activation of IKKbeta
Hsu-Ping Kuo1, Dung-Fang Lee, Weiya Xia
1Department of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
Biochemical and Biophysical Research Communications
|September 22, 2009
Summary
Tumor necrosis factor alpha (TNFalpha) increases hypoxia-inducible factor 1-alpha (HIF-1alpha) protein levels in breast cancer cells. This process requires IkappaB kinase beta (IKKbeta), a key regulator of inflammatory signaling.
Area of Science:
- Molecular Biology
- Cancer Biology
- Inflammation Research
Background:
- Hypoxia-inducible factor 1-alpha (HIF-1alpha) is a transcription factor crucial for cellular response to oxygen levels.
- Tumor necrosis factor alpha (TNFalpha) is an inflammatory mediator known to influence HIF-1alpha.
- Previous studies implicated PI3K and MAPK pathways in TNFalpha-mediated HIF-1alpha regulation.
Purpose of the Study:
- To investigate the role of IkappaB kinase beta (IKKbeta) in TNFalpha-induced HIF-1alpha regulation.
- To elucidate the signaling pathway connecting TNFalpha to HIF-1alpha accumulation in breast cancer cells.
Main Methods:
- Utilized breast cancer cell lines and IKKbeta stable clones/transfectants.
- Employed IKKbeta inhibition using Bay 11-7082.
- Analyzed HIF-1alpha and vascular endothelial growth factor (VEGF) expression.
- Examined IKKbeta and VEGF correlation in human breast cancer specimens.
Main Results:
- TNFalpha increased HIF-1alpha protein, not mRNA, in various breast cancer cells.
- IKKbeta was essential for TNFalpha-induced HIF-1alpha accumulation; IKKbeta depletion reduced HIF-1alpha levels.
- IKKbeta inhibition blocked TNFalpha-induced HIF-1alpha expression.
- IKKbeta knockout cells showed reduced VEGF expression, a HIF-1alpha target.
- A positive correlation between IKKbeta and VEGF was observed in human breast cancer samples.
Conclusions:
- TNFalpha-induced HIF-1alpha accumulation is dependent on IKKbeta.
- IKKbeta acts as a critical mediator in the inflammatory regulation of HIF-1alpha.
- Findings contribute to understanding HIF-1alpha regulation by inflammatory signals in cancer.
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