Inhibition Of Hypoxia-inducible Factor Research Articles

Hypoxia-Inducible Factor-Dependent and Independent Mechanisms Underlying Chemoresistance of Hypoxic Cancer Cells.

In hypoxic regions of malignant solid tumors, cancer cells acquire resistance to conventional therapies, such as chemotherapy and radiotherapy, causing poor prognosis in patients with cancer. It is widely recognized that some of the key genes behind this are hypoxia-inducible transcription factors, e.g., hypoxia-inducible factor 1 (HIF-1). Since HIF-1 activity is suppressed by two representative 2-oxoglutarate-dependent dioxygenases (2-OGDDs), PHDs (prolyl-4-hydroxylases), and FIH-1 (factor inhibiting hypoxia-inducible factor 1), the inactivation of 2-OGDD has been associated with cancer therapy resistance by the activation of HIF-1. Recent studies have also revealed the importance of hypoxia-responsive mechanisms independent of HIF-1 and its isoforms (collectively, HIFs). In this article, we collate the accumulated knowledge of HIF-1-dependent and independent mechanisms responsible for resistance of hypoxic cancer cells to anticancer drugs and briefly discuss the interplay between hypoxia responses, like EMT and UPR, and chemoresistance. In addition, we introduce a novel HIF-independent mechanism, which is epigenetically mediated by an acetylated histone reader protein, ATAD2, which we recently clarified.

Halofuginone prevents outer retinal degeneration in a mouse model of light-induced retinopathy.

Photoreceptor cell death can cause progressive and irreversible visual impairments. Still, effective therapies on retinal neuroprotection are not available. Hypoxia-inducible factors (HIFs) are transcriptional factors which strongly regulate angiogenesis, erythropoiesis, intracellular metabolism, and programed cell death under a hypoxic or an abnormal metabolic oxidative stress condition. Therefore, we aimed to unravel that inhibition of HIFs could prevent disease progression in photoreceptor cell death, as recent studies showed that HIFs might be pathologic factors in retinal diseases. Adult male balb/cAJcl (8 weeks old; BALB/c) were used to investigate preventive effects of a novel HIF inhibitor halofuginone (HF) on a murine model of light-induced retinopathy. After intraperitoneal injections of phosphate-buffered saline (PBS) or HF (0.4 mg/kg in PBS) for 5 days, male BALB/c mice were subjected to a dark-adaption to being exposed to a white LED light source at an intensity of 3,000 lux for 1 hour in order to induce light-induced retinal damage. After extensive light exposure, retinal damage was evaluated using electroretinography (ERG), optical coherence tomography (OCT), and TUNEL assay. Light-induced retinal dysfunction was suppressed by HF administration. The amplitudes of scotopic a-wave and b-wave as well as that of photopic b-wave were preserved in the HF-administered retina. Outer retinal thinning after extensive light exposure was suppressed by HF administration. Based on the TUNEL assay, cell death in the outer retina was seen after light exposure. However, its cell death was not detected in the HF-administered retina. Halofuginone was found to exert preventive effects on light-induced outer retinal cell death.

Ultrastable Iodinated Oil-Based Pickering Emulsion Enables Locoregional Sustained Codelivery of Hypoxia Inducible Factor-1 Inhibitor and Anticancer Drugs for Tumor Combination Chemotherapy.

Tumor hypoxia-associated drug resistance presents a major challenge for cancer chemotherapy. However, sustained delivery systems with a high loading capability of hypoxia-inducible factor-1 (HIF-1) inhibitors are still limited. Here, we developed an ultrastable iodinated oil-based Pickering emulsion (PE) to achieve locally sustained codelivery of a HIF-1 inhibitor of acriflavine and an anticancer drug of doxorubicin for tumor synergistic chemotherapy. The PE exhibited facile injectability for intratumoral administration, great radiopacity for in vivo examination, excellent physical stability (>1 mo), and long-term sustained release capability of both hydrophilic drugs (i.e., acriflavine and doxorubicin). We found that the codelivery of acriflavine and doxorubicin from the PE promoted the local accumulation and retention of both drugs using an acellular liver organ model and demonstrated significant inhibition of tumor growth in a 4T1 tumor-bearing mouse model, improving the chemotherapeutic efficacy through the synergistic effects of direct cytotoxicity with the functional suppression of HIF-1 pathways of tumor cells. Such an iodinated oil-based PE provides a great injectable sustained delivery platform of hydrophilic drugs for locoregional chemotherapy.

Marine-Derived Leads as Anticancer Candidates by Disrupting Hypoxic Signaling through Hypoxia-Inducible Factors Inhibition.

The inadequate vascularization seen in fast-growing solid tumors gives rise to hypoxic areas, fostering specific changes in gene expression that bolster tumor cell survival and metastasis, ultimately leading to unfavorable clinical prognoses across different cancer types. Hypoxia-inducible factors (HIF-1 and HIF-2) emerge as druggable pivotal players orchestrating tumor metastasis and angiogenesis, thus positioning them as prime targets for cancer treatment. A range of HIF inhibitors, notably natural compounds originating from marine organisms, exhibit encouraging anticancer properties, underscoring their significance as promising therapeutic options. Bioprospection of the marine environment is now a well-settled approach to the discovery and development of anticancer agents that might have their medicinal chemistry developed into clinical candidates. However, despite the massive increase in the number of marine natural products classified as 'anticancer leads,' most of which correspond to general cytotoxic agents, and only a few have been characterized regarding their molecular targets and mechanisms of action. The current review presents a critical analysis of inhibitors of HIF-1 and HIF-2 and hypoxia-selective compounds that have been sourced from marine organisms and that might act as new chemotherapeutic candidates or serve as templates for the development of structurally similar derivatives with improved anticancer efficacy.

Abstract 4131: Combination therapeutic strategy to fight against triple-negative breast cancer

Abstract Triple-negative breast cancers (TNBCs) lack estrogen-and progesteron receptors and human epidermal growth factor receptor-2 (HER2) which limits the therapeutic approaches. The high metastasizing capability of TNBCs is in correlation with the poor oxygenation of the cancerous breast tissue. This leads to the activation of the hypoxia-inducible-factor 1 (HIF-1), which induces multiple target genes that are involved in tumor progression and metastasis formation. This makes HIF-1 an attractive drug target, however, HIF-1 inhibitors failed if applied in monotherapy. Therefore, our aim is to investigate the combined therapeutic effect of HIF-1 inhibitor acriflavine and paclitaxel, a commonly used taxane in TNBC treatment. The synergy assessment of the two drugs was carried out by utilizing Sulforhodamine B assay on TNBC cell lines. The in vivo toxicity and efficacy of the drug combination was tested on NOD SCID mice with orthotopically inoculated MDA-MB-231 cell line. Quantitative and qualitative analysis of multiple genes involved in tumor progression was performed by mRNA and protein expression level assessment with qPCR, western blot and immunohistochemistry methods. HIF-1 stimulation was achieved by either incubating the cells at 1% oxygen level or through CoCl2 treatment. The in vitro mRNA expression studies demonstrated that acriflavin possesses a hypoxic-effect-mitigating property on the expression of metastasis-involved- and HIF-1 target genes. Acriflavine alleviated the epithelial-mesenchymal transition of TNBC cells by increasing the expression of the epithelial marker, E-cadherin. At protein level, we detected decrease in HIF-1alpha and Phospho-Protein kinase B (Akt) and increase in p53 tumor suppressor gene expression in response to acriflavine treatment. We further established MDA-MB-231 xenograft model in mice for investigating in vivo toxicity and efficacy. The drug combination efficiently reduced the tumor size and the macrometastasis formation compared to the control groups. The protein analysis of frozen tumor tissue samples indicated that the combination therapy decreased the HIF-1alpha expression and the amount of Phospho-Akt and Phospho-Mitogen-activated protein kinases (pMAPK/pERK) in CoCl2treated mice. Additionally, expression of epithelial markers increased and that of mesenchymal markers decreased. The combination therapy led to a decrease in the platelet-derived growth factor receptor beta (PDGFRB) as well. To conclude, we identified a novel drug combination which can efficiently combat TNBC by inhibiting HIF-1 signaling, mitigating cell migration and metastasis formation and suppressing the activation of the Phosphoinositide 3-kinase (PI3K) and MAPK pathways. This work was supported by the Hungarian Thematic Excellence Program (TKP2021-EGA-44) and the National Laboratories Program - National Laboratory for Tumor Biology (NLP-17). Citation Format: Laura Svajda, Ivan Ranđelović, Sára Eszter Surguta, Marcell Baranyi, István Kenessey, Mihály Cserepes, József Tóvári. Combination therapeutic strategy to fight against triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4131.

Network ethnopharmacological and molecular docking based evaluation of the anti-breast cancer activity for ayurvedic botanicals acting on hypoxia-inducible factor-1

The recognized root causes of breast cancer aggressiveness, resistance to therapy, and poor prognosis encompass hypoxia-inducible factors (HIFs), the HIF-dependent cancer hallmarks angiogenesis and metabolic reconfiguration.There is enough evidence to suggest that HIF is involved in the progression of breast cancer.Information for the network was gathered from the following databases: Dr. Duke's, IMPPAT, PubChem, Binding DB, UniProt, and DisGeNET. The network was created using the Cytoscapeprogramme. Screened bioactives having similarity index more than 0.6 from polypharmacology approach were subjected to docking studies with HIF-1 (PDB ID: 1H2K) with PyRx software and the ligands with good docking score was further explored for molecular docking interaction analysis. The number of bioactives having interaction with HIF-1, equal to or greater than 0.6 from Ashwagandh, Shatavari, Neem, Alsi seeds, Methi, Haldi, Ghritkumari, Yashtimadhu, and KadiPatta was 12, 9, 2, 6, 12, 11, 5, 10, and 3, respectively. On performing the docking against the target HIF-1for top molecules with Araboglycyrrhizin (-10.1kcal/mol), Asparanin-A (-9.2 kcal/mol), Shatavarin-I (-9.2 kcal/mol), Shatavarin-X (-9.1 kcal/mol), Somniferanolide (-9.1 kcal/mol), Somniferawithanolide (-9.7 kcal/mol), Trigofoenoside-A (-9.2 kcal/mol), Trigofoenoside-F (-9.4 kcal/mol), Trillin (-9.9 kcal/mol), and Withanolide (-9.2 kcal/mol), the binding energies and molecular interactions of the ligands were fairly good as compared with standard synthetic ligand Acriflavine (-7.6 kcal/mol). The study elucidated an in silico molecular mechanism of HIF-1 inhibition by various bioactive phytoconstituents from selected plants. Comprehending the logic behind anti-breast cancer action was made easier with the help of experimental evidence of the network findings.

HIF-1 inhibition reverses opacity in a rat model of galactose-induced cataract.

Cataract is an eye disease, in which the lens becomes opaque, causing vision loss and blindness. The detailed mechanism of cataract development has not been characterized, and effective drug therapies remain unavailable. Here, we investigated the effects of Hypoxia-inducible factor 1 (HIF-1) inhibitors using an ex vivo model, in which rat lenses were cultured in galactose-containing medium to induce opacity formation. We found that treatment with the HIF-1 inhibitors 2-Methoxyestradiol (2ME2), YC-1, and Bavachinin decreased lens opacity. Microarray analysis on 2ME2-treated samples, in which opacity was decreased, identified genes upregulated by galactose and downregulated by inhibitor treatment. Subsequent STRING analysis on genes that showed expression change by RT-qPCR identified two clusters. First cluster related to the cytoskeleton and epithelial-mesenchymal transition (EMT). Second cluster related to the oxidative stress, and apoptosis. ACTA2, a known marker for EMT, and TXNIP, a suppressor of cell proliferation and activator of apoptosis, were present in each cluster. Thus, suppression of EMT and apoptosis, as well as activation of cell proliferation, appear to underlie the decrease in lens opacity.

A40 THE ROLE OF HYPOXIA-INDUCIBLE FACTOR IN CELLULAR METABOLIC ADAPTATION UPON GIARDIA INFECTION

Abstract Background Recent findings have highlighted the integral role of oxygen tension in gastrointestinal (GI) homeostasis. During hypoxia when oxygen supply is limited, mammalian cells utilize the Hypoxia-Inducible Factor (HIF) complex to activate genes that promote cell survival and alter glucose metabolism. The GI system exists in a state of physiologic hypoxia, subject to further alterations by pathogens. Although tissue and blood parasites are known to influence tissue oxygen tension, little is known regarding the modulation of hypoxia and HIF by enteric parasites. Aims This project aims to characterize the effect of Giardia duodenalis, a common enteric protozoan that perturbs gastrointestinal function leading to diarrheal disease, on the cellular hypoxic response. We hypothesize that hypoxia-associated genes are activated upon Giardia infection, leading to an adaptive metabolic response with increased glycolytic flux to maintain cellular bioenergetic homeostasis. Methods Caco-2 colonic epithelial cells were infected with Giardia isolate GS/M (MOI 10) for 1.5 or 4.5 hours to capture early and peak HIF activation, under normoxic (21% O2) or hypoxic (1%O2, STEMCELL hypoxia incubator) conditions. RNA was extracted for RT-qPCR to assess transcriptional changes of known HIF-target genes. Intracellular metabolite analysis via liquid-chromatography mass-spectrometry (hydrophilic-interaction chromatography method) was performed to assess HIF-mediated metabolic changes in uninfected and Giardia-infected cells (MOI 10) exposed to the hypoxia mimetic DMOG or the HIF inhibitor PX-478. Results Under normoxic conditions, genes associated with compensatory cellular stress responses such as VEGFA, ANKRD37, GADD45A, and glycolysis-associated genes HK2, and LDHA are upregulated in Giardia-infected cells in a time-dependent manner (pampersand:003C0.05). Under hypoxic conditions, fewer HIF-target genes are upregulated (e.g., VEGFA, GADD45A, PGK1; pampersand:003C0.05), suggesting Giardia-infected cells behave similarly to uninfected cells with constant HIF activation. Analysis of the Caco-2 intracellular metabolome indicates HIF-dependent changes in amino acid (e.g., glycine, threonine) and nucleic acid (e.g., guanosine, inosine, uracil) metabolism. DMOG treatment altered the production of glycolytic intermediates (e.g., DHAP, PEP), confirming the promotion of glycolytic flux by HIF. Conclusions Both cell-stress-related and glucose-metabolism HIF target genes are activated upon Giardia infection. As well, some metabolic changes are dependent on HIF activation. These novel findings indicate Giardia promotes a hypoxic state in human intestinal cells, highlighting a metabolic cell rescue mechanism in response to enteropathogens. Furthermore, understanding the role of hypoxia in enteric parasitic infections will shed light on the potential of HIF as a therapeutic target. Funding Agencies Natural Sciences and Engineering Research Council of Canada (NSERC)

Therapeutic Targeting of Hypoxia-Inducible Factors in Cancer.

In the realm of cancer therapeutics, targeting the hypoxia-inducible factor (HIF) pathway has emerged as a promising strategy. This study delves into the intricate web of HIF-associated mechanisms, exploring avenues for future anticancer therapies. Framing the investigation within the broader context of cancer progression and hypoxia response, this article aims to decipher the pivotal role played by HIF in regulating genes influencing angiogenesis, cell proliferation, and glucose metabolism. Employing diverse approaches such as HIF inhibitors, anti-angiogenic therapies, and hypoxia-activated prodrugs, the research methodologically intervenes at different nodes of the HIF pathway. Findings showcase the efficacy of agents like EZN-2968, Minnelide, and Acriflavine in modulating HIF-1α protein synthesis and destabilizing HIF-1, providing preliminary proof of HIF-1α mRNA modulation and antitumor activity. However, challenges, including toxicity, necessitate continued exploration and development, as exemplified by ongoing clinical trials. This article concludes by emphasizing the potential of targeted HIF therapies in disrupting cancer-related signaling pathways.

The Role of the PTEN Tumor Suppressor Gene and Its Anti-Angiogenic Activity in Melanoma and Other Cancers.

Human malignant melanoma and other solid cancers are largely driven by the inactivation of tumor suppressor genes and angiogenesis. Conventional treatments for cancer (surgery, radiation therapy, and chemotherapy) are employed as first-line treatments for solid cancers but are often ineffective as monotherapies due to resistance and toxicity. Thus, targeted therapies, such as bevacizumab, which targets vascular endothelial growth factor, have been approved by the US Food and Drug Administration (FDA) as angiogenesis inhibitors. The downregulation of the tumor suppressor, phosphatase tensin homolog (PTEN), occurs in 30-40% of human malignant melanomas, thereby elucidating the importance of the upregulation of PTEN activity. Phosphatase tensin homolog (PTEN) is modulated at the transcriptional, translational, and post-translational levels and regulates key signaling pathways such as the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) pathways, which also drive angiogenesis. This review discusses the inhibition of angiogenesis through the upregulation of PTEN and the inhibition of hypoxia-inducible factor 1 alpha (HIF-1-α) in human malignant melanoma, as no targeted therapies have been approved by the FDA for the inhibition of angiogenesis in human malignant melanoma. The emergence of nanocarrier formulations to enhance the pharmacokinetic profile of phytochemicals that upregulate PTEN activity and improve the upregulation of PTEN has also been discussed.

Detection of FG-4592 and metabolites in equine plasma, urine and hair following oral administration.

FG-4592 is a hypoxia-inducible factor inhibitor that has been approved for therapeutic use in some countries. This class of compounds can increase the oxygen carrying capacity of the blood and thus have the potential to be used as performance enhancing agents in sports. The purpose of this study was to investigate the detection of FG-4592 and metabolites in equine plasma and mane hair following a multiple dose oral administration to two Thoroughbred racehorses, to identify the best analytical targets for doping control laboratories. Urine samples were also analysed, and the results compared to previously published urine data. Liquid chromatography-high resolution mass spectrometry was used for metabolite identification in urine and plasma. Liquid chromatography-tandem mass spectrometry was used for full sample analysis of urine, plasma and hair samples and generation of urine and plasma profiles. FG-4592 and a mono-hydroxylated metabolite were detected in plasma. FG-4592 was detected with the greatest abundance and gave the longest duration of detection, up to 312 h post-administration, and would be the recommended target in routine doping samples. FG-4592 was detected in all mane hair samples collected post-administration, up to 166 days following the final dose, showing extended detection can be achieved with this matrix. To the best of the authors' knowledge, this is the first report of FG-4592 and metabolites in equine plasma and hair samples. Urine results were consistent with the previously published data, with FG-4592 offering the best target for detection and longest detection periods.

Roxadustat ameliorates experimental colitis in mice by regulating macrophage polarization through increasing HIF level

BackgroundGastro-intestinal (GI) tract inflammation is as a result of inflammatory hypoxia which is also induced by long-standing group of disorders like inflammatory-bowel disease (IBD). Regulation of GI immune homeostasis by macrophage involves hypoxia-inducible factor (HIF). As inhibitor of HIF prolyl hydroxylase, roxadustat (ROX) increases the levels of HIF. MethodsWe induced experimental colitis (EC) model in mice via dextran-sulfate sodium (DSS) to evaluate ROX role in above-mentioned disease. ResultsROX ameliorated EC in mice by blocking colonic length shorten and loss of body weight, thereby reducing scores of disease-activity index (DAI) and histopathology. ROX significantly reduced inflammatory cytokines levels, suppressed M1 and increased M2 macrophage polarization in colonic tissues. Besides, ROX blocked declining hematocrit (HCT) level in blood and increased HIF-1-α and HIF-2-α level in colonic tissues. The inhibitor of HIF-1- α, KC7F2 decreased body weight and colonic length in ROX-treated DSS mice. Meanwhile, DAI scores and histopathology in KC7F2 treated DSS mice were markedly higher than that of treatment with ROX alone. KC7F2 treatments also significantly increased inflammatory cytokines levels, respectively promoted and reduced polarization of M1 and M2 macrophages in colonic tissue from ROX treated mice. Further, KC7F2 treatments inhibited ROX induced HCT level increasing in blood and decreased HIF-1-α and HIF-2-α level in colonic tissue. ConclusionCollectively, we discovered that ROX ameliorated EC in mice by regulating macrophage polarization through promotion of HIF expression. General significanceTaken together, we developed a new application of ROX, which provides new ideas and a scientific basis for IBD treatment.

MUC1 aptamer-conjugated niclosamide-loaded PLGA-PEG nanoparticles attenuate HIF-1 stabilization upon hypoxia in MCF7 breast cancer cells

Hypoxia is related to aggressive phenotype and poor prognosis in breast cancer. HIF-1, a transcription factor (TF), plays an essential role in the adaptation of tumor cells to hypoxia. It is stabilized in hypoxic conditions and activates other TFs and signaling pathways that are associated with the proliferation, survival, and progression of cancer cells in hypoxia. As a result, targeting hypoxia by destabilizing HIF-1 is a promising approach to inhibit cell adaptation to hypoxia. Niclosamide (NIC) has been identified as a HIF-1 inhibitor and it is envisioned that the anti-cancer efficacy of NIC can be improved through targeted drug delivery systems (DDSs) as a therapeutic strategy. Here, MUC1 aptamer (Ap)-targeted PLGA/PEGylated nanoparticles (Ap-PLGA-NPs) were developed for targeted delivery of NIC (Ap-NIC-PLGA-NPs) to MUC1 positive breast cancer cell line in hypoxia environment. The obtained findings showed that targeted inhibition of HIF-1 using fabricated targeted-NIC-loaded NPs increased the rate of apoptosis in breast cancer cells in hypoxic conditions which was further confirmed by geno-/cytotoxicity assays and flow cytometry analysis. Downregulation of HIF-1α, HIF-1β, Eno1, and GluT1 in treated breast cancer cells under hypoxic conditions also indicated a potential role for Ap-NIC-PLGA-NPs in tumor cell adaptation to hypoxia.

Targeting hypoxia-inducible factors: therapeutic opportunities and challenges.

Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that are crucial for adaptation of metazoans to limited oxygen availability. Recently, HIF activation and inhibition have emerged as therapeutic targets in various human diseases. Pharmacologically desirable effects of HIF activation include erythropoiesis stimulation, cellular metabolism optimization during hypoxia and adaptive responses during ischaemia and inflammation. By contrast, HIF inhibition has been explored as a therapy for various cancers, retinal neovascularization and pulmonary hypertension. This Review discusses the biochemical mechanisms that control HIF stabilization and the molecular strategies that can be exploited pharmacologically to activate or inhibit HIFs. In addition, we examine medical conditions that benefit from targeting HIFs, the potential side effects of HIF activation or inhibition and future challenges in this field.

Yeni Sentezlenen Potansiyel HIF İnhibitörlerinin Hipoksik Koşullarda Küçük Hücre Dışı Akciğer Kanseri Üzerindeki İnhibitör Etkilerinin Belirlenmesi

According to global estimates, there are 2.3 million new cases and 1.8 million fatalities due to lung cancer each year. Despite recent progress in diagnosis and treatment, persistent challenges highlight the urgent need for novel therapeutics and innovative approaches to combat lung cancer effectively. Accordingly, in the present study, we aimed to investigate the anticancer properties of potential inhibitors of HIF-1α, compound 7a and 7b. In the study, HTB-54 and BEAS-2B cell lines were used. MTT cell viability experiments were performed to determine the effect of newly synthesized HIF inhibitors 7a and 7b on cell viability under normoxic and hypoxic conditions. Quantitative expression levels of HIF1A were determined by real-time PCR approach. While the half maximum inhibitory concentration (IC50) of compound 7a in HTB-54 cells was 10.37 µM under normoxic conditions, it was found to be 10.63 µM under hypoxic conditions. The IC50 value of another HIF inhibitor 7b in HTB-54 cells was found to be 8.80 µM under normoxic conditions and 9.54 µM under hypoxic conditions. The expression level of HIF1A was found to be lower in cells exposed to compounds 7a and 7b under hypoxia compared to the control group. Conversely, in normoxia, HIF1A expression level in cells exposed to compound 7a increased 6.5-fold (p<0.0001) compared to the control group, while it was found to increase approximately 9-fold (p<0.0001) when exposed to 7b. Consequently, both compound 7a and 7b holds great promise for future therapeutic interventions to lung cancer.

Hair and dietary supplements testing to identify contamination with roxadustat in an adverse analytical finding

Roxadustat is an oral inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase, which increases endogenous erythropoiesis. WADA has included roxadustat and other HIF stabilizers on its list of prohibited substances. We describe here the case of an elite athlete (female, 31 years old, 168 cm and 53 kg) with an adverse analytical finding (AAF) with concentration of roxadustat in her urine at 0.289 ng/mL in the A sample and 0.529 ng/mL in the B sample (83% higher than A). A stability study was carried out, showing total stability of roxadustat at this concentration in urine exposed to light for 50 h, so photoisomerization degradation cannot explain the difference in concentration. Her urine had been completely negative in a control test carried out three days previously, while roxadustat had been shown to be present in urine for at least 20 days after administration of pharmacologically effective doses to an athlete. Hair concentration was 0.39 and 0.35 pg/mg in the segments corresponding to the presumed period of intake, with few adjacent segments also positive (0.29–0.33 pg/mg), likely explained by cosmetic treatments. Concentrations found in a patient treated with a pharmacologically active dose (between 100 and 120 mg 3 days a week) were more than 100 times higher (between 41 and 57 pg/mg). Numerous supplements and pharmaceuticals taken by the athlete were analyzed. Only collagen powder showed the presence of roxadustat, at a very low but highly variable concentration (100 pg/g-1000 pg/g). A female volunteer (58 years old, 169 cm and 65 kg), taking this powder at the same doses as the athlete (10 g of powder 5 times for 6 days) presented 7 roxadustat-positive urine samples (although lower than those observed in the athlete) out of 34 sampled over 7 days, the difference in powder sampling location, age, weight, height, pharmacokinetic parameters variability and level of sporting activity between the athlete and the volunteer probably explaining the difference in concentrations observed. All these results could be consistent with an AAF due to contamination by dietary supplements, which are becoming increasingly common due to the current exposome of athletes in our society.

Pathologic vs. protective roles of hypoxia-inducible factor 1 in RPE and photoreceptors in wet vs. dry age-related macular degeneration.

It has previously been reported that antioxidant vitamins can help reduce the risk of vision loss associated with progression to advanced age-related macular degeneration (AMD), a leading cause of visual impairment among the elderly. Nonetheless, how oxidative stress contributes to the development of choroidal neovascularization (CNV) in some AMD patients and geographic atrophy (GA) in others is poorly understood. Here, we provide evidence demonstrating that oxidative stress cooperates with hypoxia to synergistically stimulate the accumulation of hypoxia-inducible factor (HIF)-1α in the retinal pigment epithelium (RPE), resulting in increased expression of the HIF-1-dependent angiogenic mediators that promote CNV. HIF-1 inhibition blocked the expression of these angiogenic mediators and prevented CNV development in an animal model of ocular oxidative stress, demonstrating the pathological role of HIF-1 in response to oxidative stress stimulation in neovascular AMD. While human-induced pluripotent stem cell (hiPSC)-derived RPE monolayers exposed to chemical oxidants resulted in disorganization and disruption of their normal architecture, RPE cells proved remarkably resistant to oxidative stress. Conversely, equivalent doses of chemical oxidants resulted in apoptosis of hiPSC-derived retinal photoreceptors. Pharmacologic inhibition of HIF-1 in the mouse retina enhanced-while HIF-1 augmentation reduced-photoreceptor apoptosis in two mouse models for oxidative stress, consistent with a protective role for HIF-1 in photoreceptors in patients with advanced dry AMD. Collectively, these results suggest that in patients with AMD, increased expression of HIF-1α in RPE exposed to oxidative stress promotes the development of CNV, but inadequate HIF-1α expression in photoreceptors contributes to the development of GA.

The role of belzutifan, an inhibitor of hypoxia-inducible factor, for renal cell carcinoma in adults with Von Hippel–Lindau disease: a review

The role of belzutifan, an inhibitor of hypoxia-inducible factor, for renal cell carcinoma in adults with Von Hippel–Lindau disease: a review

Interaction and Collaboration of SP1, HIF-1, and MYC in Regulating the Expression of Cancer-Related Genes to Further Enhance Anticancer Drug Development.

Specificity protein 1 (SP1), hypoxia-inducible factor 1 (HIF-1), and MYC are important transcription factors (TFs). SP1, a constitutively expressed housekeeping gene, regulates diverse yet distinct biological activities; MYC is a master regulator of all key cellular activities including cell metabolism and proliferation; and HIF-1, whose protein level is rapidly increased when the local tissue oxygen concentration decreases, functions as a mediator of hypoxic signals. Systems analyses of the regulatory networks in cancer have shown that SP1, HIF-1, and MYC belong to a group of TFs that function as master regulators of cancer. Therefore, the contributions of these TFs are crucial to the development of cancer. SP1, HIF-1, and MYC are often overexpressed in tumors, which indicates the importance of their roles in the development of cancer. Thus, proper manipulation of SP1, HIF-1, and MYC by appropriate agents could have a strong negative impact on cancer development. Under these circumstances, these TFs have naturally become major targets for anticancer drug development. Accordingly, there are currently many SP1 or HIF-1 inhibitors available; however, designing efficient MYC inhibitors has been extremely difficult. Studies have shown that SP1, HIF-1, and MYC modulate the expression of each other and collaborate to regulate the expression of numerous genes. In this review, we provide an overview of the interactions and collaborations of SP1, HIF1A, and MYC in the regulation of various cancer-related genes, and their potential implications in the development of anticancer therapy.

HIF-1α inhibition by MO-2097, a novel chiral-free benzofuran targeting hnRNPA2B1

IntroductionHypoxia-inducible factor 1 (HIF-1) is a transcriptional activator mediating adaptive responses to hypoxia. It is up-regulated in the tumor microenvironment and recognized as an effective anticancer drug target. Previously, we discovered that the natural compound moracin-O and its synthetic derivative MO-460 inhibited HIF-1α via hnRNPA2B1. ObjectivesThis study aimed to develop novel HIF-1 inhibitors for cancer chemotherapy by harnessing the potential of the natural products moracins-O and P. MethodsIn an ongoing search for novel HIF-1 inhibitors, a series of nature-inspired benzofurans with modifications on the chiral rings of moracins-O and P were synthesized. They showed improved chemical tractability and were evaluated for their inhibitory activity on HIF-1α accumulation under hypoxic conditions in HeLa CCL2 cells. The most potent derivative's chemical-based toxicities, binding affinities, and in vivo anti-tumorigenic effects were evaluated. Further, we examined whether our compound, MO-2097, exhibited anticancer effects in three-dimensional cultured organoids. ResultsHerein, we identified a novel synthetic chiral-free compound, MO-2097, with reduced structural complexity and increased efficiency. MO-2097 exhibited inhibitory effects on hypoxia-induced HIF-1α accumulation in HeLa CCL2 cells via inhibition of hnRNPA2B1 protein, whose binding affinities were confirmed by isothermal titration calorimetry analysis. In addition, MO-2097 demonstrated in vivo efficacy and biocompatibility in a BALB/c mice xenograft model. The immunohistochemistry staining of MO-2097-treated tissues showed decreased expression of HIF-1α and increased levels of apoptosis marker cleaved caspase 3, confirming in vivo efficacy. Furthermore, we confirmed that MO-2097 works effectively in cancer patient-based organoid models. ConclusionMO-2097 represents a promising new generation of chemotherapeutic agents targeting HIF-1α inhibition via hnRNPA2B1, requiring further investigation.