In:
Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 7, No. 12 ( 2008-12-01), p. 3729-3738
Abstract:
Hypoxia-inducible factor (HIF)-1 plays a key role in tumor promotion by inducing ∼60 genes required for tumor adaptation to hypoxia; thus, it is viewed as a target for cancer therapy. For this reason, YC-1, which down-regulates HIF-1α and HIF-2α at the post-translational level, is being developed as a novel anticancer drug. We here found that YC-1 acts in a novel manner to inhibit HIF-1. In the Gal4 reporter system, which is not degraded by YC-1, YC-1 was found to significantly inactivate the COOH-terminal transactivation domain (CAD) of HIF-1α, whereas it failed to inactivate CAD(N803A) mutant. In coimmunoprecipitation assays, YC-1 stimulated factor inhibiting HIF (FIH) binding to CAD even in hypoxia, whereas it failed to increase the cellular levels of hydroxylated Asn803 of CAD. It was also found that YC-1 prevented p300 recruitment by CAD in mammalian two-hybrid and coimmunoprecipitation assays. The involvement of FIH in YC-1-induced CAD inactivation was confirmed in EPO-enhancer and Gal4 reporter systems using FIH small interfering RNA and dimethyloxalylglycine FIH inhibitor. Indeed, FIH inhibition rescued HIF target gene expressions repressed by YC-1. In cancer cell lines other than Hep3B, YC-1 inhibits HIF-1α via the FIH-dependent CAD inactivation as well as via the protein down-regulation. Given these results, we suggest that the functional inactivation of HIF-α contributes to the YC-1-induced deregulation of hypoxia-induced genes. [Mol Cancer Ther 2008;7(12):3729–38]
Type of Medium:
Online Resource
ISSN:
1535-7163
,
1538-8514
DOI:
10.1158/1535-7163.MCT-08-0074
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2008
detail.hit.zdb_id:
2062135-8
SSG:
12
Permalink