Cited by 58Cancer, Hypoxia, and MetabolismEnzyme function and inhibitionAngiogenesis and VEGF in Cancer

Suppression of the Hypoxia-Inducible Factor-1 Response in Cervical Carcinoma Xenografts by Proteasome Inhibitors

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Birle, Diana C., Hedley, David W.·2007·Cancer Research

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Abstract

Experimental data suggest therapeutic advantage from selective disruption of the hypoxia response. We recently found that the proteasome inhibitor bortezomib decreases tumor carbonic anhydrase IX (CAIX) expression in colon cancer patients and herein report a companion laboratory study to test if this effect was the result of hypoxia-inducible factor (HIF) inhibition. Human cervical (SiHa and Me180) and colon (RKO) carcinoma cell lines were treated with bortezomib or the structurally unrelated proteasome inhibitor MG132 in normoxic and hypoxic conditions in vitro. Two different in vivo experiments investigated bortezomib effects after single dose (2 mg/kg, 24 h) or longer exposure in severe combined immunodeficient mice bearing SiHa xenografts. Treatment with either drug produced accumulation of HIF-1alpha in vitro but strongly inhibited the production of CAIX and vascular endothelial growth factor (VEGF) under hypoxia. This correlated with more than 10-fold reduction in HIF-1 transcriptional activity under hypoxic conditions. A similar effect of bortezomib was seen in vivo, using the nitroimidazole probe EF5 to define regions of tumor hypoxia and a triple immunofluorescence technique to measure the spatial distributions of HIF-1alpha and CAIX. Plasma VEGF levels decreased by approximately 90% during treatment with bortezomib, indicating that this agent can potently inhibit the hypoxia response in tumors.

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  • Bortezomib is associated with suppression of HIF-1 signaling despite expectation that proteasome inhibition would stabilize HIF-α subunits.

    “bortezomib, a clinically approved proteasome inhibitor used in multiple myeloma, has been repeatedly associated with suppression of HIF-1 signaling, despite the expectation that proteasome inhibition would stabilize HIF-α subunits [[336], [337], [338]].”

    From HIF inhibition: Current strategies and clinical challenges (2026) · cites this paper as [337]

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Authors
Birle, D. C., & Hedley, D. W.
Affiliations
  • 1Division of Applied Molecular Oncology, Ontario Cancer Institute and
  • University of Toronto (CA)
Venue
Cancer Research
Published
2007-02-15
Volume
67
Issue
4
Pages
1735-1743
ISSN
  • 0008-5472 (ISSN-L)
  • 1538-7445
OpenAlex
W2081753042
Cited by
58
References
51
Citations by year
2026: 1 · 2024: 1 · 2023: 4 · 2022: 3 · 2021: 3 · 2020: 1 · 2017: 1 · 2016: 2 · 2015: 4 · 2014: 2 · 2013: 1 · 2012: 6
FWCI
2.57
Type
journal article
Language
en
Open access
Locations
  • Cancer Research (publishedVersion)
  • PubMed (publishedVersion)
Funders
National Cancer Institute
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Cancer, Hypoxia, and Metabolism
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Enzyme function and inhibition
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Angiogenesis and VEGF in Cancer
Keywords
HIF-1, HIF-1α, bortezomib, proteasome inhibitors, MG132, carbonic anhydrase IX, vascular endothelial growth factor, tumor hypoxia, cervical cancer, colon cancer, xenografts, HIF-1 transcriptional activity
MeSH terms
Bortezomib, Carbonic Anhydrase IX, Antigens, Neoplasm, Antineoplastic Agents, Boronic Acids, Carbonic Anhydrases, Carcinoma, Squamous Cell, Cell Nucleus, Uterine Cervical Neoplasms, Colonic Neoplasms, Enzyme Activation, Female, Humans, Leupeptins, Male, Prostatic Neoplasms, Protease Inhibitors, Protein Binding, Pyrazines, Cell Hypoxia, Xenograft Model Antitumor Assays, Vascular Endothelial Growth Factor A, Cell Line, Tumor, E1A-Associated p300 Protein, Hypoxia-Inducible Factor 1, alpha Subunit, Caspase 3

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