Amphotericin B blunts erythropoietin response to hypoxia by reinforcing FIH-mediated repression of HIF-1

Yeo, Eui‐Ju; Ryu, Ji Hye; Cho, Young Suk; Chun, Yang Sook; Huang, L. Eric; Kim, Myung Suk; Park, Jong-Wan

doi:10.1182/blood-2005-06-2564

Cited by 76 publications

(43 citation statements)

References 36 publications

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“…21 Total RNAs were isolated using TRIZOL (Invitrogen, Carlsbad, CA). RNAs (1 g) were reversetranscribed at 48°C and the cDNAs were amplified over 18 to 23 PCR cycles in a 20 L of reaction mixture containing 0.185 MBq (5 Ci) [␣-32 P]dCTP and 250 nM of each primer set.…”

Section: Semiquantitative Rt-pcrmentioning

confidence: 99%

“…21 EPO enhancer-luciferase and VEGF promoter-luciferase reporter genes, HA-FIH plasmid, and FIH siRNA duplex were constructed as previously described. 21,22 The Gal4-CAD plasmid was constructed by inserting HIF-1␣ CAD (aa 776-826) into pCMX-G4(N), and the Gal4-CAD(N803A) plasmid was generated by site-directed mutagenesis. 22 The VP16-CH1 plasmid was constructed by inserting the CH1 domain of p300 into the VP16 plasmid (Clontech, Palo Alto, CA).…”

Section: Preparation Of Plasmids and Sirnasmentioning

confidence: 99%

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Bortezomib inhibits tumor adaptation to hypoxia by stimulating the FIH-mediated repression of hypoxia-inducible factor-1

Shin¹,

Chun²,

Lee

et al. 2008

Blood

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149

113

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Bortezomib (PS-341), a proteasome inhibitor, has been examined clinically for the treatment of multiple myeloma and several solid tumors. Bortezomib directly induces tumor cell death and has also been reported to inhibit tumor adaptation to hypoxia by functionally inhibiting hypoxia-inducible factor-1␣ (HIF-1␣). However, the mechanism underlying HIF-1 inhibition by bortezomib remains obscure. In the present study, we demonstrated that bortezomib attenuated the hypoxic induction of erythropoietin and vascular endothelial growth factor at subnanomolar concentrations in multiple myeloma and liver cancer cell lines, regardless of cytotoxic concentrations of bortezomib. Bortezomib repressed HIF-1␣ activity by inhibiting the recruitment of p300 coactivator. Specifically, bortezomib targeted HIF-1␣ C-terminal transactivation domain (CAD) but not the CAD lacking Asn803, which is a hydroxylation site by the factor inhibiting HIF-1 (FIH). Accordingly, this effect of bortezomib on CAD was augmented by FIH expression and abolished by FIH knock-down. Furthermore, bortezomib stimulated the interaction between CAD and FIH under hypoxic conditions, and FIH inhibition reversed the suppressions of erythropoietin and vascular endothelial growth factor by bortezomib. We propose that the mechanism underlying the inhibitory effects of bortezomib on tumor angiogenesis and hypoxic adaptation involves the repression of HIF-1␣ transcriptional activity by reinforcing the FIH-mediated inhibition of p300 recruitment. IntroductionHypoxia commonly develops in solid tumors because tumor growth outpaces vessel formation and because the blood supply is compromised due to aberrant vasculature formation. 1 Tumor hypoxia contributes to angiogenesis and modulates tumor energy metabolism, which are both essential required for tumor growth. 2 In multiple myeloma (MM), hypoxia is also an important environmental factor because bone marrow is intrinsically hypoxic in nature. 3 Thus, MM cells must survive and grow under such hypoxic conditions, and this requires the expressions of many genes essential for adaptation. Hypoxic adaptation is mainly provided by hypoxia-inducible factor-1 (HIF-1), which orchestrates cellular adaptation to hypoxia by transactivating about 60 genes. 4 HIF-1 is composed of HIF-1␣ and HIF-1␤/aryl hydrocarbon nuclear translocator (ARNT), 5 and of these, HIF-1␣ is the key protein that determines the presence of HIF-1 and transactivates genes. Under normoxic conditions, HIF-1␣ is hydroxylated at its Pro402 and Pro564 residues by HIF-1 prolyl hydroxylases (PHDs), and thus, targeted by von Hippel-Lindau protein (pVHL), ubiquitinated, and finally degraded by 26S proteasomes. [6][7][8][9][10] In addition, the C-terminal transactivation domain (CAD) of HIF-1␣ is hydroxylated at Asn803 by the factor inhibiting HIF-1 (FIH), which represses the transcriptional activity of HIF-1␣ by blocking the recruitment of p300 coactivator. 11,12 However, PHD and FIH activities depend on oxygen tension, and as a result HIF-1␣ is stabilized and activated...

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Section: Semiquantitative Rt-pcrmentioning

confidence: 99%

Section: Preparation Of Plasmids and Sirnasmentioning

confidence: 99%

Bortezomib inhibits tumor adaptation to hypoxia by stimulating the FIH-mediated repression of hypoxia-inducible factor-1

Shin¹,

Chun²,

Lee

et al. 2008

Blood

Self Cite

149

113

View full text Add to dashboard Cite

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“…The VP16-CH1 plasmid was constructed by recombination of the p300 CH1 cDNA and the VP16 plasmid (24). HA-tagged FIH plasmid, FIH small interfering RNA (siRNA), and green fluorescent protein siRNA were constructed as described previously (22). To express or to knock down genes, cells at 40% confluence in 60 mm dishes were transfected with plasmid or siRNA using calcium phosphate or Lipofectamine (Invitrogen) method.…”

Section: Methodsmentioning

confidence: 99%

“…To quantify mRNA levels, we used a highly sensitive semiquantitative reverse transcription-PCR as described previously (22). Total RNAs, extracted using Trizol (Invitrogen), were reverse transcribed at 46jC for 20 min and the cDNAs were amplified over 18 (for VEGF) or 28 (for EPO) PCR cycles (94jC for 30 s, 53jC for 30 s, and 70jC for 30 s) in a 20 AL reaction mixture containing 5 ACi [a-…”

Section: Methodsmentioning

confidence: 99%

“…Another proteasome inhibitor, MG132, also inactivates HIF-1a by stimulating the CITED2-mediated interference of CAD-p300 binding (21). Moreover, amphotericin B (an antifungal agent) inactivates HIF-1a by stimulating the CAD-FIH interaction, which may cause erythropoietin-deficient anemia associated with amphotericin B therapy (22). Given these reports, it appears that CAD inactivation could contribute to the pharmacologic actions of anti-HIF agents.…”

Section: Introductionmentioning

confidence: 99%

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A novel mode of action of YC-1 in HIF inhibition: stimulation of FIH-dependent p300 dissociation from HIF-1α

Li¹,

Shin²,

Chun

et al. 2008

Molecular Cancer Therapeutics

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143

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Hypoxia-inducible factor (HIF)-1 plays a key role in tumor promotion by inducing f60 genes required for tumor adaptation to hypoxia; thus, it is viewed as a target for cancer therapy. For this reason, YC-1, which downregulates HIF-1A and HIF-2A 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-1A, 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 Asn 803 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-1A via the FIHdependent CAD inactivation as well as via the protein down-regulation. Given these results, we suggest that the functional inactivation of HIF-A contributes to the YC-1-induced deregulation of hypoxia-induced genes.

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Antifungal Agents and Therapy

Reiss

Shadomy

Lyon

2011

Fundamental Medical Mycology

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Amphotericin B blunts erythropoietin response to hypoxia by reinforcing FIH-mediated repression of HIF-1

Cited by 76 publications

References 36 publications

Bortezomib inhibits tumor adaptation to hypoxia by stimulating the FIH-mediated repression of hypoxia-inducible factor-1

Bortezomib inhibits tumor adaptation to hypoxia by stimulating the FIH-mediated repression of hypoxia-inducible factor-1

A novel mode of action of YC-1 in HIF inhibition: stimulation of FIH-dependent p300 dissociation from HIF-1α

Antifungal Agents and Therapy

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