Release Summary Text:
● A Novel Mechanism Elucidated: Researchers have discovered that using specific "iron-mobilizing iron chelators" blocks the function of cellular oxygen sensor enzymes. This induces a state of "functional pseudohypoxia"—tricking cells into believing there is a lack of oxygen, even in a fully oxygenated environment.
● Unleashing Dormant Potential: When this "false hypoxia alarm" goes off, it triggers the cells' emergency switches, simultaneously releasing and rebooting the body's own powerful, dormant capabilities for immunity (anti-tumor effects) and tissue repair (nerve regeneration).
● A New Platform for Intractable Diseases: This method improved the therapeutic efficacy against colorectal and lung cancers, which are typically resistant to existing immunotherapies. Furthermore, in aged mouse models, it suppressed the decline of cognitive function (working memory) without causing brain inflammation. This approach is expected to become a completely new platform treatment concept for intractable diseases.
Full text of release:
Current Status and Challenges
Cancer and dementia are severe diseases that affect a vast number of people in our super-aging society. In recent years, immune checkpoint inhibitors (ICIs) have improved treatment outcomes for lung and colorectal cancers. However, overcoming tumors that respond poorly to ICIs, such as Microsatellite-Stable (MSS) colorectal cancer—which accounts for the vast majority of colorectal cancer cases—is an urgent challenge. In dementia, antibody treatments targeting causative substances are under development, but a definitive method to boost declined cognitive functions and fundamentally halt the loss of memory has yet to be established. Therefore, there is a strong demand for therapies that safely and powerfully boost overall immunity and cellular repair capabilities.
Mechanism of the Research Results: "Pseudohypoxia" Induced by Iron-Mobilizing Chelators
Traditional "iron-targeting" cancer therapies focused on starving cells of iron to kill them. In contrast, this research group has elucidated a paradigm-shifting mechanism: rather than simply depleting iron, the drug binds to iron to rewrite intracellular signaling.
1. Activating the Emergency Switch with a "False Hypoxia Alarm" Our cells use sensor enzymes (PHD) to monitor oxygen levels. Normally, these enzymes use iron and oxygen to degrade HIF-1α, a protein that manages cellular adaptation. When iron-mobilizing chelators (such as Roxadustat or SP10) are administered, they act as a surrogate key—entering the enzyme's active center and blocking its function by displacing 2-oxoglutarate (2-OG). This tricks the cell into a state of "Pseudohypoxia," sounding a false alarm that oxygen is scarce.
2. IL-2 Secretion Awakens "Elite" Immune Forces Under pseudohypoxia, HIF-1α accumulates and triggers the secretion of Interleukin-2 (IL-2) from both T cells and cancer cells. This IL-2 revitalizes exhausted CD8-positive T cells (killer T cells) within the tumor, transforming them into highly aggressive effector cells. When combined with standard anti-PD-1 antibodies, this approach powerfully surrounds and eliminates tumor cells that were previously resistant to treatment.
3. Awakening Repair Capabilities Without Inflammation This "limiter-removing" approach also shows promise for neuroregeneration. In aged mice, inducing pseudohypoxia activated regeneration signals (Tau and JNK pathways) and preserved working memory performance. Crucially, this was achieved without elevating harmful inflammatory markers (such as Iba1 or GFAP), suggesting a safe way to reboot the brain's repair functions.
Social Significance
This research proposes the unique concept of "functional pseudohypoxia" to intentionally and safely reboot the body's dormant potential. By "removing the limiters" of our biological defense mechanisms, this platform offers a new frontier in fighting intractable diseases, extending healthy lifespans, and reducing the global burden of cancer and dementia.
Publication Details
Title of original paper: HIF-PH inhibitors induce pseudohypoxia in T cells and suppress the growth of microsatellite stable colorectal cancer by enhancing antitumor immune responses.
Journal: Cancer Immunology, Immunotherapy
Authors: Yuehua Chen, Toshiaki Ohara, Yusuke Hamada, Yuze Wang, Miao Tian, Kazuhiro Noma, Hiroshi Tazawa, Masayoshi Fujisawa, Teizo Yoshimura, Akihiro Matsukawa
DOI: https://doi.org/10.1007/s00262-025-04067-3
URL: https://link.springer.com/article/10.1007/s00262-025-04067-3
Title of original paper: Pseudohypoxia induced by iron chelator activates tumor immune response in lung cancer.
Journal: Free Radical Research
Authors: Yusuke Hamada, Toshiaki Ohara, Yuehua Chen, Manato Terada, Yuze Wang, Hotaka Kawai, Masayoshi Fujisawa, Teizo Yoshimura, Akihiro Matsukawa
DOI: https://doi.org/10.1080/10715762.2025.2551030
URL: https://www.tandfonline.com/doi/full/10.1080/10715762.2025.2551030
Title of original paper: Pseudohypoxia induced by iron chelators preserves working memory performance in aged mice.
Journal: Scientific Reports
Authors: Toshiaki Ohara, Yoshiaki Iwasaki, Tomonari Kasai, Toru Yamashita, Shiho Komaki, Yusuke Hamada, Masayoshi Fujisawa, Akihiro Matsukawa
DOI: https://doi.org/10.1038/s41598-026-42296-3
URL: https://www.nature.com/articles/s41598-026-42296-3
Related Patent Information:
PCT/JP2025/033487
Funding:
This research was supported by the Japan Society for the Promotion of Science (JSPS KAKENHI Grant Numbers 22K08712, 25K11863), the Ryobi Teien Memorial Foundation, the Sanyo Broadcasting Academic, Cultural and Sports Promotion Foundation, and the Teraoka Memorial Scholarship Foundation.
Contact information
Contact Person:
Toshiaki Ohara, Research Associate Professor
Department of Pathology & Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
Phone: +81-86-235-7143