University of Michigan Rogel Cancer Center researchers have unveiled a groundbreaking metabolic mechanism that colorectal cancer cells exploit to maintain exceptionally high iron levels, a discovery that opens promising avenues for targeted cancer therapies. Published recently in Cell Metabolism, this study provides an unprecedented insight into how tumor cells sidestep iron toxicity and evade a form of cell death known as ferroptosis, potentially revolutionizing the understanding of metal metabolism in cancer biology.

Colorectal cancer cells are known to harbor elevated iron concentrations, far surpassing those found in healthy cells. Iron is a double-edged sword in cellular physiology—essential for processes like DNA synthesis and cell proliferation but lethal in excess due to its propensity to generate harmful reactive oxygen species. Ordinarily, cells with excessive iron succumb to ferroptosis, a specialized form of oxidative cell death driven by iron-mediated lipid peroxidation. Tumor cells subvert this natural safeguard, sustaining iron overload without triggering their own demise, but how they achieve this has remained elusive—until now.

The investigative team led by Dr. Yatrik Shah, Horace W. Davenport Collegiate Professor of Physiology at Michigan Medicine, employed a metabolism-directed CRISPR screening approach to systematically dissect the pathways protecting colorectal cancer cells from iron-induced oxidative damage. Surprisingly, canonical ferroptotic enzymes, previously presumed central to this resistance, were found non-essential for tumor survival. This redirected focus led the scientists to explore mitochondrial metabolism more profoundly.

Their research unveiled that the mitochondrial enzyme complex II plays a pivotal role in safeguarding cancer cells from iron-induced toxicity. Complex II regulates coenzyme Q (CoQ) within mitochondria, a key antioxidant molecule that quells oxidative stress. By fine-tuning CoQ’s redox state, complex II effectively buffers the destructive potential of accumulated iron, preventing ferroptosis and enabling cancer cell proliferation. When researchers knocked out complex II in colorectal cancer models, iron toxicity became unmanageable for the tumor cells, leading to widespread cell death and marked tumor growth inhibition.

Crucially, complex II’s protective mechanism appears specific to the high-iron environment of cancer cells. In mouse models, disruption of complex II elicited negligible adverse effects on normal tissues, underscoring the therapeutic potential of selectively targeting this mitochondrial axis in colorectal cancer. This specificity addresses a significant hurdle in oncology: minimizing treatment toxicity while maximizing antitumor efficacy.

Further intricacies emerged as the study revealed a feedback loop wherein iron itself modulates complex II activity, suggesting a sophisticated regulatory axis that maintains iron homeostasis within tumors. This bidirectional interaction offers additional molecular targets for disrupting iron tolerance in cancer cells and deepening our understanding of tumor metabolism.

These findings represent a paradigm shift from earlier hypotheses centered on canonical ferroptosis regulators, highlighting the necessity of focusing on mitochondrial metabolism in cancer research. By leveraging sophisticated genome-editing tools and bioenergetic profiling, the Rogel Cancer Center team charted a novel course for drug discovery efforts aimed at crippling iron addiction—a hallmark of not only colorectal but potentially many other malignancies.

The next phase of this research endeavors to identify and develop potent inhibitors of complex II or its associated metabolic pathways. Given that dysregulated iron metabolism is a common vulnerability across diverse cancer types, these interventions could herald a new era of broad-spectrum anticancer strategies. Moreover, detailed characterization of iron complex II interplay might uncover additional metabolic dependencies exploitable for therapeutic gains.

This transformative research underscores the intricate metabolic adaptations that empower colorectal cancers to circumvent intrinsic iron toxicity constraints. By illuminating the heme-complex II axis as a linchpin in maintaining oxidative balance amid iron overload, it offers a highly selective target for the design of next-generation anticancer agents.

Researchers anticipate that combining complex II inhibition with other therapies may amplify treatment responses and overcome resistance mechanisms. As the quest to outsmart cancer evolves, this study reinforces the vital role of mitochondrial metabolism understanding in crafting innovative clinical interventions.

In sum, the University of Michigan team’s discovery of complex II’s role in buffering iron toxicity not only deciphers a long-standing biological enigma but also charts a compelling translational pathway. It epitomizes how fundamental metabolic insights can accelerate the development of precision treatments conferring hope to millions affected by colorectal cancer worldwide.

Subject of Research: Cells
Article Title: Iron addicted colorectal cancers exploit heme-complex II axis to resist oxidative cell death
News Publication Date: June 17, 2026
Web References: http://dx.doi.org/10.1016/j.cmet.2026.04.020
References: “Iron addicted colorectal cancers exploit heme-complex II axis to resist oxidative cell death,” Cell Metabolism, DOI: 10.1016/j.cmet.2026.04.020
Image Credits: Shah Lab, Rogel Cancer Center
Keywords: Colorectal cancer, iron metabolism, ferroptosis, complex II, coenzyme Q, mitochondrial metabolism, oxidative cell death, tumor metabolism, cancer therapy

A groundbreaking fluorescent reporter enabling real-time visualization of biologically active iron and oxygen at the single-cell level inside living organisms has been developed by researchers at the Institute of Science Tokyo. This revolutionary tool, named LiON (labile iron and oxygen notifier), ushers in a new era for cellular biology by offering unprecedented insight into the dynamic interplay and distribution of these essential elements within living tissues. Published in the esteemed journal Cell Reports Methods, this innovation promises to transform the study of fundamental physiological processes and complex diseases, from oncology and liver pathology to neurodegenerative disorders and aging.

Iron and oxygen are indispensable to cellular function, acting as core contributors to energy production, metabolic regulation, and DNA synthesis. Despite their vital roles, maintaining the delicate balance and spatial distribution of labile ferrous iron and reactive oxygen species remains critical, as disruptions often lead to cellular damage and disease. Historically, the challenge has been the absence of imaging tools capable of monitoring these elements within living cells at sufficient resolution, particularly differentiating biologically active forms from inert reservoirs.

Traditional methods of detecting iron, such as histochemical staining or mass spectrometry, require fixed tissue samples, offering only static snapshots devoid of temporal context. Although advanced clinical imaging modalities like magnetic resonance imaging enable in vivo iron mapping, they lack cellular resolution and fail to discriminate between active and stored iron pools. This limitation impairs the ability to study cellular heterogeneity and microenvironmental influences critical to disease pathogenesis.

To bridge this gap, the team led by Professor Toshiro Moroishi and doctoral researcher Ayato Maeda ingeniously exploited the iron- and oxygen-sensitive regulatory domain of FBXL5, a protein known to undergo degradation in low-iron and low-oxygen conditions. By genetically fusing this domain to a red fluorescent protein while coupling it with a stable green fluorescent protein, they engineered a ratiometric biosensor. Variations in red-to-green fluorescence ratios directly reflect intracellular labile iron and oxygen levels, enabling precise, quantitative assessments at single-cell resolution in living tissues.

Generating transgenic mice expressing LiON, the investigators revealed remarkable gradients and heterogeneity in iron and oxygen distribution across various organs and within homogeneous cell populations. For instance, they identified spatially distinct iron accumulation proximal to portal veins in the liver, highlighting areas susceptible to oxidative stress and metabolic dysfunction. These nuanced observations suggest complex regulatory mechanisms governing iron homeostasis that could not previously be elucidated in vivo.

Beyond fundamental biology, the capacity to monitor labile iron and oxygen in living systems has profound clinical implications. Iron dysregulation and hypoxia are hallmarks of cancer progression, neurodegeneration, and age-related tissue decline. The ability to dynamically track these parameters within specific cell types allows for the investigation of pathophysiological processes at an unprecedented scale, facilitating the development and evaluation of targeted therapies.

Importantly, the modular genetic design of LiON enables conditional activation in defined tissues or cell populations using well-established genetic tools. This versatility empowers researchers to tailor investigations according to disease models or biological questions, drastically expanding the utility of this fluorescent reporter across scientific disciplines. It also paves the way for high-throughput screening approaches and longitudinal studies previously unattainable.

Technically, the LiON sensor leverages competitive degradation pathways mediated by FBXL5’s hemerythrin-like domain, which senses iron and oxygen availability to regulate protein stability. When iron and oxygen are sufficient, FBXL5 remains stable, maintaining the red fluorescence. Under conditions of deficiency, FBXL5 is degraded, reducing red fluorescence and shifting the fluorescence ratio. By normalizing against stable green fluorescence, this ratiometric approach cancels out confounding factors such as expression levels or photobleaching, ensuring robust quantification.

Further development of LiON may enable integration with multiphoton or super-resolution microscopy, amplifying the ability to investigate cellular metabolism and microenvironmental niches in unprecedented detail. Moreover, its application in live imaging models can accelerate translational research by offering real-time insights into therapeutic interventions and disease progression, a vital step toward precision medicine.

The researchers emphasize that understanding heterogeneity in iron and oxygen management at the single-cell level will clarify diverse cellular responses within tissues, facilitating the identification of vulnerable or resistant cell populations. This information is invaluable for unraveling mechanisms underpinning complex diseases, optimizing drug delivery, and minimizing off-target effects.

As the first fluorescent reporter capable of in vivo, single-cell resolution imaging of labile iron and oxygen, LiON represents a transformative leap forward. The integration of this tool into mainstream biomedical research has the potential to catalyze breakthroughs spanning from fundamental cell biology to clinical therapeutics, establishing a new paradigm in the visualization and understanding of elemental biology.

In the words of Professor Moroishi, “LiON opens a window into cellular microenvironments that were previously invisible, enabling us to observe and quantify critical biochemical landscapes that dictate health and disease. We anticipate that this technology will become an indispensable asset across many branches of life science research.”

With the establishment of the Institute of Science Tokyo, a visionary new institution formed through the union of Tokyo Medical and Dental University and Tokyo Institute of Technology, this breakthrough exemplifies a commitment to pioneering innovative science aimed at enhancing human well-being. The convergence of multidisciplinary expertise and cutting-edge technology exemplified by LiON underscores the promise of collaborative research to address some of the most pressing biomedical challenges of our time.

---

Subject of Research: Animals
Article Title: In vivo visualization of bioactive iron and oxygen using LiON, the labile iron and oxygen notifier
News Publication Date: 8-May-2026
Web References: DOI: 10.1016/j.crmeth.2026.101431
Image Credits: Institute of Science Tokyo
Keywords: Life sciences, Cell biology, Fluorescent proteins, Biomolecules, Biochemistry, Iron, Oxygen, Human health, Diseases and disorders, Neurodegenerative diseases, Cancer research, Clinical medicine

In the ongoing battle against prostate cancer, researchers have uncovered a biochemical pathway that promises to revolutionize treatment strategies. A recent study by Zhang, H., Feng, T., Lv, M., and colleagues, published in Cell Death Discovery, reveals how quinolinic acid, a metabolite derived from the enzyme HAAO, significantly influences androgen receptor (AR) signaling via an FDPS-dependent mechanism. This discovery not only deepens our understanding of prostate cancer biology but also highlights a novel avenue for enhancing the efficacy of combination therapies.

Prostate cancer remains one of the most prevalent malignancies affecting men worldwide, with androgen receptor signaling playing a pivotal role in disease progression and therapy resistance. Androgen deprivation therapies (ADT) have long been the frontline treatment; however, many patients eventually develop castration-resistant prostate cancer (CRPC), underscoring the urgent need for new molecular targets and therapeutic strategies. The study conducted by Zhang and colleagues brings to light the critical interplay between metabolites in the kynurenine pathway and AR signaling, potentially offering new hope for overcoming therapeutic resistance.

Central to their findings is quinolinic acid (QA), a metabolite produced downstream of 3-hydroxyanthranilic acid oxygenase (HAAO) activity within the kynurenine pathway of tryptophan metabolism. Quinolinic acid has traditionally been studied for its neurotoxic properties, but this research innovatively identifies QA as a key modulator within prostate cancer cells. The team demonstrated that HAAO expression is markedly elevated in prostate cancer tissues, correlating with advanced disease stages and poorer prognosis.

Mechanistically, quinolinic acid appears to fuel FDPS (farnesyl diphosphate synthase)-dependent androgen receptor signaling. FDPS is a crucial enzyme in the mevalonate pathway, responsible for the synthesis of isoprenoids, which are vital for protein prenylation and cellular proliferation. The researchers showed that elevated QA enhances FDPS activity, leading to increased AR signaling activity. This hyperactivation of AR signaling amplifies cancer cell growth and survival, facilitating resistance to standard therapies.

What makes this discovery particularly compelling is the demonstration that modulating levels of quinolinic acid can sensitize prostate cancer cells to combination therapeutic approaches. The study revealed that inhibiting HAAO or reducing quinolinic acid production diminishes FDPS-dependent AR signaling, thereby suppressing tumor cell proliferation and improving the effectiveness of anti-androgen drugs. These findings suggest a promising therapeutic window where targeting metabolic pathways can synergize with hormonal therapies to overcome resistance.

The implications of these results extend beyond a simple metabolic snapshot. They connect two major biological systems—the kynurenine pathway and the mevalonate pathway—each with independent significance in cancer biology but now linked through quinolinic acid’s regulatory effects. This metabolic crosstalk introduces a paradigm shift in how metabolic intermediates can be exploited to influence oncogenic signaling cascades.

Moreover, the study utilized a combination of advanced molecular techniques including transcriptomics, metabolomics, and functional assays in both in vitro and in vivo models. These comprehensive approaches validated the critical role of HAAO-derived quinolinic acid and its impact on FDPS expression and activity. Importantly, patient-derived xenografts and clinical data underscored the translational relevance of the findings, suggesting readiness for clinical exploration.

Therapeutically, the prospect of combining HAAO inhibitors or agents targeting quinolinic acid synthesis with established anti-androgen therapies such as enzalutamide marks a significant advancement. This combination strategy could potentially prevent or delay the onset of treatment resistance, a major hurdle in managing advanced prostate cancer. Additionally, the study hints at the broader possibility of targeting metabolic vulnerabilities in other androgen-driven cancers.

From a mechanistic perspective, the identification of quinolinic acid as an oncometabolite challenges previous notions relegating it to neurotoxicity roles. It invites further exploration of how metabolic byproducts can act as signaling molecules within the tumor microenvironment, influencing cancer cell behavior and treatment outcomes. This insight opens doors for novel biomarkers that can predict response to therapy and guide personalized medicine approaches.

Furthermore, the study paves the way to investigate whether similar metabolic dependencies exist in other malignancies where steroid hormone receptor signaling is critical. If so, the HAAO-FDPS-AR axis may become a universal target across multiple cancer types, broadening the scope of therapeutic interventions beyond prostate cancer alone.

On the molecular signaling axis, the team discovered that quinolinic acid’s impact on FDPS promotes AR nuclear translocation and transcriptional activity, leading to enhanced expression of AR target genes that drive proliferation and survival pathways. This detailed mechanistic insight provides concrete targets for pharmacological intervention and biomarker development.

This groundbreaking study also raises important questions about the metabolic plasticity of cancer cells and their ability to adapt biosynthetic pathways to sustain oncogenic signaling. Understanding how cancer cells leverage metabolites like quinolinic acid could illuminate resistance mechanisms and identify vulnerabilities exploitable by combination therapies.

In conclusion, the elucidation of HAAO-derived quinolinic acid as a central actor fueling FDPS-dependent androgen receptor signaling heralds a novel metabolic axis driving prostate cancer progression and therapy resistance. By bridging metabolic biochemistry and signal transduction, the research sets the stage for innovative treatment paradigms that combine metabolic inhibition with hormonal therapy, potentially transforming patient outcomes in prostate cancer and beyond.

Zhang and colleagues’ work exemplifies the power of integrative omics and translational research in unraveling complex cancer biology, inviting the scientific community to rethink how metabolic intermediates can be harnessed in the fight against malignancy. As research advances, the HAAO-quinolinic acid-FDPS-AR signaling axis may well become a cornerstone in precision oncology strategies targeting prostate cancer metabolism and hormone receptor signaling.

---

Subject of Research: Prostate cancer metabolism and androgen receptor signaling modulation by HAAO-derived quinolinic acid.

Article Title: HAAO-derived quinolinic acid fuels FDPS-dependent AR signaling and sensitizes prostate cancer to combination therapy.

Article References:
Zhang, H., Feng, T., Lv, M. et al. HAAO‑derived quinolinic acid fuels FDPS‑dependent AR signaling and sensitizes prostate cancer to combination therapy. Cell Death Discov. (2026). https://doi.org/10.1038/s41420-026-03203-x

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41420-026-03203-x

In a mouse study conducted by scientists at the Dasman Diabetes Institute in Kuwait, rodents fed a sucrose-free diet developed insulin resistance, gut microbial imbalances and signs of fatty liver disease despite maintaining similar body weight.

The post Eliminating Sucrose from Low-Fat Diet Alters Gut Microbiome, Animal Study Suggests appeared first on Sci.News: Breaking Science News.

In new research, scientists sequenced and analyzed chromosome-level genomes of the Linnaeus’s two-toed sloth (Choloepus didactylus) and the southern anteater (Tamandua tetradactyla).

The post Secret to Sloths’ Slow Life May Lie in Ancient ‘Jumping Genes’ appeared first on Sci.News: Breaking Science News.

Scientists discovered a hidden gut-brain network that can change cravings when the body needs more protein. The body has a remarkable ability to recognize when it is missing important nutrients and adjust behavior accordingly. New research shows that the gut plays a much larger role in this process than previously understood, actively detecting protein shortages [...]

A new AI framework called MouseMapper allows scientists to examine disease-related changes across the entire body at cellular resolution. Obesity does much more than affect metabolism and fat storage. It also changes immune activity, nerve structure, and tissue organization throughout the body, raising the risk of conditions such as type 2 diabetes, cardiovascular disease, stroke, [...]

Scientists identified phosphatidylcholine loss as a key driver of mitochondrial aging and showed that restoring it can rejuvenate cellular energy networks. Why do cells age, and why do people gradually lose energy and vitality over time? Scientists have long focused on mitochondria, the tiny structures inside cells responsible for producing energy. Researchers now understand that [...]

In a small clinical trial, researchers at the Ohio State University found that a tomato juice rich in lycopene and soy isoflavones lowered several proteins linked to chronic inflammation, raising hopes for food-based therapies.

The post Tomato-Soy Drink May Help Fight Chronic Inflammation in Adults with Obesity appeared first on Sci.News: Breaking Science News.