The 2-oxoglutarate analog 3-oxoglutarate decreases normoxic hypoxia-inducible factor-1α in cancer cells, induces cell death, and reduces tumor xenograft growth.

TitleThe 2-oxoglutarate analog 3-oxoglutarate decreases normoxic hypoxia-inducible factor-1α in cancer cells, induces cell death, and reduces tumor xenograft growth.
Publication TypeJournal Article
Year of Publication2016
AuthorsKoivunen, P, Fell, SM, Lu, W, Rabinowitz, JD, Kung, AL, Schlisio, S
JournalHypoxia (Auckl)
Volume4
Pagination15-27
Date Published2016
Abstract

The cellular response to hypoxia is primarily regulated by the hypoxia-inducible factors (HIFs). HIF-1α is also a major mediator of tumor physiology, and its abundance is correlated with therapeutic resistance in a broad range of cancers. Accumulation of HIF-1α under hypoxia is mainly controlled by the oxygen-sensing HIF prolyl 4-hydroxylases (EGLNs, also known as PHDs). Here, we identified a high level of normoxic HIF-1α protein in various cancer cell lines. EGLNs require oxygen and 2-oxoglutarate for enzymatic activity. We tested the ability of several cell-permeable 2-oxoglutarate analogs to regulate the abundance of HIF-1α protein. We identified 3-oxoglutarate as a potent regulator of HIF-1α in normoxic conditions. In contrast to 2-oxoglutarate, 3-oxoglutarate decreased the abundance of HIF-1α protein in several cancer cell lines in normoxia and diminished HIF-1α levels independent of EGLN enzymatic activity. Furthermore, we observed that 3-oxoglutarate was detrimental to cancer cell survival. We show that esterified 3-oxoglutarate, in combination with the cancer chemotherapeutic drug vincristine, induces apoptosis and inhibits tumor growth in vitro and in vivo. Our data imply that a novel treatment strategy targeting HIF-1α in combination with the use of existing cytotoxic agents could serve as potent, future antitumor chemotherapies.

DOI10.2147/HP.S96366
Alternate JournalHypoxia (Auckl)
PubMed ID27525289
PubMed Central IDPMC4981084
Grant ListR01 CA163591 / CA / NCI NIH HHS / United States