The combination of hypoxia-response enhancers and an oxygen-dependent proteolytic motif enables real-time imaging of absolute HIF-1 activity in tumor xenografts

Harada, Hiroshi; Kizaka‐Kondoh, Shinae; Itasaka, Satoshi; Shibuya, Kazuhiko; Morinibu, Akiyo; Shinomiya, Kazumi; Hiraoka, Masahiro

doi:10.1016/j.bbrc.2007.06.149

Cited by 60 publications

(77 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…RCC4/Vector and RCC4/VHL were transfected with the plasmid p5HRE-ODD-luc (Harada et al, 2007b) by the calcium phosphate method (Chen and Okayama, 1987) to establish RCC4/Vector/ 5HREp-ODD-Luc and RCC4/VHL/5HREp-ODD-Luc cells, respectively, and cultured for 10 days in medium containing 400 mg ml À1 of G418 (Nacalai Tesque, Kyoto, Japan). Antibiotic-resistant colonies showing HIF-1-dependent bioluminescence were isolated and established as clones.…”

Section: Isolation Of Stable Transfectantsmentioning

confidence: 99%

“…The cells were cultured for an additional 24 h under normoxic or hypoxic conditions, and subjected to western blotting with anti-HIF-1a antibody (BD Bioscience, San Diego, CA, USA) and with anti-bactin antibody (BioVision Research Products, Mountain View, CA, USA) or to luciferase assay (Promega), as described earlier Harada et al, 2007b). On the other hand, the normoxic or hypoxic conditional medium was subjected to human VEGF ELISA system (GE healthcare UK Ltd, Buckinghamshire, UK) to analyse the secreted VEGF level, according to the manufacturer's instructions.…”

Section: Luciferase Assay For Rcc4-derived Stable Transfectantsmentioning

confidence: 99%

“…A representative clone was used in this study. HeLa/EFp-Luc and HeLa/5HREp-ODD-Luc cells were established as described earlier (Harada et al, , 2007b.…”

Section: Isolation Of Stable Transfectantsmentioning

confidence: 99%

“…In this study, we performed a series of optical and real-time imaging experiments using an HIF-1-dependent reporter gene, 5HRE-ODD-luc (Harada et al, 2007b), and analysed the changes in intratumoral HIF-1 activity after treatment with radiation and/or an HIF-1 inhibitor, YC-1. The imaging experiments revealed that intratumoral HIF-1 activity decreased at 6 h postirradiation, and then increased and peaked at 18 -24 h postirradiation.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Treatment regimen determines whether an HIF-1 inhibitor enhances or inhibits the effect of radiation therapy

et al. 2009

View full text Add to dashboard Cite

Hypoxia-inducible factor-1 (HIF-1) has been reported to promote tumour radioresistance; therefore, it is recognised as an excellent target during radiation therapy. However, the inhibition of HIF-1 in unsuitable timing can suppress rather than enhance the effect of radiation therapy because its anti-angiogenic effect increases the radioresistant hypoxic fraction. In this study, we imaged changes of HIF-1 activity after treatment with radiation and/or an HIF-1 inhibitor, YC-1, and optimised their combination. Hypoxic tumour cells were reoxygenated 6 h postirradiation, leading to von Hippel-Lindau (VHL)-dependent proteolysis of HIF-1a and a resultant decrease in HIF-1 activity. The activity then increased as HIF-1a accumulated in the reoxygenated regions 24 h postirradiation. Meanwhile, YC-1 temporarily but significantly suppressed HIF-1 activity, leading to a decrease in microvessel density and an increase in tumour hypoxia. On treatment with YC-1 and then radiation, the YC-1-mediated increase in tumour hypoxia suppressed the effect of radiation therapy, whereas on treatment in the reverse order, YC-1 suppressed the postirradiation upregulation of HIF-1 activity and consequently delayed tumour growth. These results indicate that treatment regimen determines whether an HIF-1 inhibitor enhances or inhibits the therapeutic effect of radiation, and the suppression of the postirradiation upregulation of HIF-1 activity is important for the best therapeutic benefit.

show abstract

Section: Isolation Of Stable Transfectantsmentioning

confidence: 99%

Section: Luciferase Assay For Rcc4-derived Stable Transfectantsmentioning

confidence: 99%

“…A representative clone was used in this study. HeLa/EFp-Luc and HeLa/5HREp-ODD-Luc cells were established as described earlier (Harada et al, , 2007b.…”

Section: Isolation Of Stable Transfectantsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Treatment regimen determines whether an HIF-1 inhibitor enhances or inhibits the effect of radiation therapy

et al. 2009

View full text Add to dashboard Cite

show abstract

“…An additional means of modulating transgene expression is based on extensive molecular characterization of HIF-a subunits, which has provided maps of domains that are essential for oxygen-dependent stability and efficient transcriptional activity. 32,33 Thus, it is now possible to utilize this information for tighter conditional regulation of therapeutic gene strategies, which have the goal of generating chimeric toxic proteins with decreased stability under normoxic conditions and conversely increased stability during hypoxia. 10 We have previously shown that an HRE-based promoter could be used in conjunction with green fluorescent protein to aid in the mapping of hypoxic regions of solid tumors.…”

Section: Discussionmentioning

confidence: 99%

Hypoxia-induced human endonuclease G expression suppresses tumor growth in a xenograft model

et al. 2008

View full text Add to dashboard Cite

We have developed a hypoxia-inducible gene therapy approach for the expression of the mature form of human endonuclease G to facilitate cell death in hypoxic regions of the tumor. The chimeric therapeutic gene is placed under the control of a hypoxia response element based promoter and contains a translocation motif linked in frame to an oxygen-dependent degradation domain and the endonuclease G gene. Transient expression of the chimeric therapeutic gene in breast and prostate cancer cell lines resulted in efficient cell death under hypoxia-mimetic conditions. Stable MDA-MB-435 cells expressing the chimeric therapeutic gene under 1% O 2 showed an increase in stable HIF-1a protein levels and synthesis of the endonuclease G protein in a time-dependent manner. In normoxic conditions, these stable transgenic cells exhibited no change in growth rate, invasion and motility when compared to parental cells. Moreover, xenografts generated using the transgenic cells exhibited highly significant suppression of tumor growth in a preclinical cancer model compared to the parental cell line. Thus, the hypoxia-modulated endonuclease G expression has the potential to be used as a gene-based-therapy system to kill malignant cells within hypoxic regions of tumors.

show abstract

Generation of a hypoxia‐sensing mouse model

Lin

Huang

Giordano

et al. 2019

Genesis

View full text Add to dashboard Cite

Summary Oxygen (O2) homeostasis is essential to the metazoan life. O2‐sensing or hypoxia‐regulated molecular pathways are intimately involved in a wide range of critical cellular functions and cell survival from embryogenesis to adulthood. In this report, we have designed an innovative hypoxia sensor (O2CreER) based on the O2‐dependent degradation domain of the hypoxia‐inducible factor‐1α and Cre recombinase. We have further generated a hypoxia‐sensing mouse model, R26‐O2CreER, by targeted insertion of the O2CreER‐coding cassette in the ROSA26 locus. Using the ROSAmTmG mouse strain as a reporter, we have found that this novel hypoxia‐sensing mouse model can specifically identify hypoxic cells under the pathological condition of hind‐limb ischemia in adult mice. This model can also label embryonic cells including vibrissal follicle cells in E13.5–E15.5 embryos. This novel mouse model offers a valuable genetic tool for the study of hypoxia and O2 sensing in mammalian systems under both physiological and pathological conditions.

show abstract

The combination of hypoxia-response enhancers and an oxygen-dependent proteolytic motif enables real-time imaging of absolute HIF-1 activity in tumor xenografts

Cited by 60 publications

References 16 publications

Treatment regimen determines whether an HIF-1 inhibitor enhances or inhibits the effect of radiation therapy

Treatment regimen determines whether an HIF-1 inhibitor enhances or inhibits the effect of radiation therapy

Hypoxia-induced human endonuclease G expression suppresses tumor growth in a xenograft model

Generation of a hypoxia‐sensing mouse model

Contact Info

Product

Resources

About