Hypoxia-inducible Factor Research Articles

Plasma-based proteomic and metabolomic characterization of lung and lymph node metastases in cervical cancer patients

Metastasis is the leading cause of mortality in cervical cancer (CC), with a particular prevalence of lymph node and lung metastases. Patients with CC who have developed distant metastases typically face a poor prognosis, and there is a scarcity of non-invasive strategies for predicting CC metastasis. In this study, we utilized label-free proteomics and untargeted metabolomics to analyze plasma samples from 25 non-metastatic, 14 with lung metastasis, and 15 with lymph node metastasis CC patients. Pathway enrichment analysis revealed a shared inflammatory process between the two metastatic groups, while the central carbon metabolism in cancer showed distinct features in the lung metastasis cohort. Additionally, cholesterol metabolism, hypoxia-inducible factor 1, and ferroptosis signaling pathways were specifically altered in the lymph node metastasis group. Utilizing the receiver operating characteristic curve analysis and Random Forest algorithm, we identified two distinct biomarker panels for the prediction of lung metastasis and lymph node metastasis, respectively. The lung metastasis panel includes properdin, neural cell adhesion molecule 1, and keratin 6 A, whereas the lymph node metastasis panel consists of quiescin sulfhydryl oxidase 1, paraoxonase 1, and keratin 6 A. Each panel exhibited significant diagnostic potential, with high area under the curve (AUC) values for lung metastasis (training set: 0.989, testing set: 0.789) and lymph node metastasis (training set: 0.973, testing set: 0.900). This study conducted an integrated proteomic and metabolomic analysis to clarify the factors contributing to lung and lymph node metastases in CC and has successfully established two biomarker panels for their prediction.

Hypoxia drives estrogen receptor β-mediated cell growth via transcription activation in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a highly malignant tumor with a poor prognosis. Hypoxia conditions affect multiple cellular processes promoting the adaptation and progression of cancer cells via the activation of hypoxia-inducible factors (HIF) and subsequent transcription activation of their target genes. Preliminary studies have suggested that estrogen receptor β (ERβ) might play a promoting role in the progression of NSCLC. However, the precise mechanisms, particularly its connection to HIF-1α-mediated modulation under hypoxia, remain unclear. Our findings demonstrated that the overexpression of ERβ, not ERα, increased cell proliferation and inhibition of apoptosis in NSCLC cells and xenografts. Tissue microarray staining revealed a strong correlation between the protein expression of HIF-1α and ERβ. HIF-1α induced ERβ gene transcription and protein expression in CoCl2-induced hypoxia, 1% O2 incubation, or HIF-1α overexpressing cells. ChIP identified HIF-1α binding to a hypoxia response element in the ESR2 promoter. The suppression of HIF-1α and ERβ both in vitro and in vivo effectively reduced the tumor growth, thus emphasizing the promising prospects of targeting HIF-1α and ERβ as a therapeutic approach for the treatment of NSCLC. KEY MESSAGES: ERβ, not ERα, increases cell proliferation and inhibition of apoptosis in NSCLC cells and xenografts. A strong correlation exists between the protein expression of HIF-1α and ERβ. HIF-1α induced ERβ gene transcription and protein expression in hypoxic cells via binding to HRE in the ESR2 promoter. The suppression of HIF-1α and ERβ both in vitro and in vivo effectively reduced the NSCLC tumor growth.

Genistein inhibits HIF-1α and attenuates high glucose-induced peritoneal mesothelial-mesenchymal transition and fibrosis via the mTOR/OGT pathway

Peritoneal fibrosis has been linked to hypoxia-inducible factor 1-alpha (HIF-1α) as well as O-linked-N-acetylglucosaminylation (O-GlcNAcylation) in peritoneal dialysis (PD). Genistein, recognized for its HIF-1α inhibitory and antifibrotic effects, presents a potential intervention against peritoneal mesothelial-mesenchymal transition (MMT) as well as fibrosis in PD. This study employed human peritoneal mesothelial cells (HPMCs) together with adenine-induced chronic kidney disease (CKD) rats undergoing peritoneal dialysis to explore Genistein’s role in high glucose-induced peritoneal MMT and fibrosis. Our findings reveal that Genistein exerts anti-MMT and anti-fibrotic effects by inhibiting HIF-1α in HPMCs under high glucose conditions. Genistein inhibited O-GlcNAcylation status of HIF-1α through the mTOR/O-GlcNAc transferase (OGT) pathway, promoting its ubiquitination as well as the subsequent proteasomal degradation. In adenine-induced CKD rats undergoing peritoneal dialysis, Genistein suppressed the mTOR/OGT expression and reduced the abundance of O-GlcNAcylation along with HIF-1α in the peritoneum. Additionally, Genistein protected against increased peritoneal thickness, fibrosis, and angiogenesis, while improving peritoneal function. Based on our results, it could be inferred that Genistein might inhibit the abundance of HIF-1α via the mTOR/OGT pathway, thereby ameliorating MMT as well as fibrosis in PD.

3D biological scaffold delivers Bergenin to reduce neuroinflammation in rats with cerebral hemorrhage

BackgroundIntracerebral hemorrhage (ICH) is a severe form of stroke characterized by high incidence and mortality rates. Currently, there is a significant lack of effective treatments aimed at improving clinical outcomes. Our research team has developed a three-dimensional (3D) biological scaffold that incorporates Bergenin, allowing for the sustained release of the compound.MethodsThis 3D biological scaffold was fabricated using a combination of photoinitiator, GEMA, silk fibroin, and decellularized brain matrix (dECM) to encapsulate Bergenin through advanced 3D bioprinting techniques. The kinetics of drug release were evaluated through both in vivo and in vitro studies. A cerebral hemorrhage model was established, and a 3D biological scaffold containing Bergenin was transplanted in situ. Levels of inflammatory response, oxidative stress, and apoptosis were quantified. The neurological function of rats with cerebral hemorrhage was assessed on days 1, 3, and 5 using the turning test, forelimb placement test, Longa score, and Bederson score.ResultsThe 3D biological scaffold incorporating Bergenin significantly enhances the maintenance of drug concentration in the bloodstream, leading to a marked reduction in inflammatory markers such as IL-6, iNOS, and COX-2 levels in a cerebral hemorrhage model, primarily through the inhibition of the NF-κB pathway. Additionally, the scaffold effectively reduces the expression of hypoxia-inducible factor 1-alpha (HIF-1α) in primary cultured astrocytes, which in turn decreases the production of reactive oxygen species (ROS) and inhibits IL-6 production induced by hemin. Subsequent experiments reveal that the 3D biological scaffold containing Bergenin promotes the activation of the Nrf-2/HO-1 signaling pathway, both in vivo and in vitro, thereby preventing cell death. Moreover, the application of this 3D biological scaffold has been demonstrated to improve drug retention in the bloodstream.ConclusionThis strategy effectively mitigates inflammation, oxidative stress, and cell death in rats with cerebral hemorrhage by inhibiting the NF-κB pathway while concurrently activating the Nrf-2/HO-1 pathway.

In Vitro Investigation of HIF-1α as a Therapeutic Target for Thyroid-Associated Ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO) involves tissue expansion and inflammation, potentially causing a hypoxic microenvironment. Hypoxia-inducible factor (HIF)-1α is crucial in fibrosis and adipogenesis, which are observed in TAO progression. We investigated the effects of hypoxia on orbital fibroblasts (OFs) in TAO, focusing on the role of HIF-1α in TAO progression. OFs were isolated from TAO and non-TAO patients (as controls). In addition to HIF-1α, adipogenic differentiation markers including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein (CEBP) were measured by Western blot, and phenotype changes were evaluated by Oil Red O staining under both normoxia and hypoxia. To elucidate the effect of HIF-1α inhibition, protein expression changes after HIF-1α inhibitor treatment were evaluated under normoxia and hypoxia. TAO OFs exhibited significantly higher HIF-1α expression than non-TAO OFs, and the difference was more distinct under hypoxia than under normoxia. Oil Red O staining showed that adipogenic differentiation of TAO OFs was prominent under hypoxia. Hypoxic conditions increased the expression of adipogenic markers, namely PPARγ and CEBP, as well as HIF-1α in TAO OFs. Interleukin 6 levels also increased in response to hypoxia. The effect of hypoxia on adipogenesis was reduced at the protein level after HIF-1α inhibitor treatment, and this inhibitory effect was sustained even with IGF-1 stimulation in addition to hypoxia. Hypoxia induces tissue remodeling in TAO by stimulating adipogenesis through HIF-1α activation. These data could provide insights into new treatment strategies and the mechanisms of adipose tissue remodeling in TAO.

Ficus carica Puree Exerts a Higher Antioxidative Profile in Hypoxic Lungs after Intermittently Inducing Hypoxia in Sprague–Dawley Rats

Abstract Background: The body produces more hypoxia-inducible factor and reactive oxygen species in response to hypoxic situations because they cause unbalanced oxygen levels. Ficus carica provides numerous benefits because of its high antioxidant and mineral content. Nevertheless, the mechanism by which F. carica consumption confers this protective benefit remains incompletely understood. Aim: This study aimed to evaluate how F. carica puree (FCP) can affect the antioxidant enzyme activity and malondialdehyde (MDA) levels in the lung by mitigating the effects of intermittent hypoxia (IH). Methods: Thirty Sprague–Dawley rats were divided into five groups negative control (NC), untreated; positive control (PC), treated with aquadest; FCP1; FCP2; and FCP3, which received FCP at doses of 1.25, 2.5, and 5 mL/200 g body weight. The treatment was administered for 4 weeks before inducing IH (10% O2 and 90% N2) into all groups (except NC) for 4 h for 7 days. Furthermore, hemoglobin (Hb) level, lung MDA level, and lung superoxide dismutase (SOD) enzyme activity were assessed. Results: The Hb level did not exhibit a significant increase under IH conditions. Conversely, the PC group exhibited the least activity of lung antioxidant enzymes and the highest lung MDA levels. In addition, the FCP intervention group exhibited lower MDA levels than the PC group and ameliorated relative lung weight loss. Conclusion: All FCP intervention groups showed lower MDA levels and higher SOD levels compared to the PC group, suggesting that FCP could mitigate the effects of hypoxia in rat lungs.

TME-responsive nanoplatform for multimodal imaging-guided synergistic precision therapy of esophageal cancer via inhibiting HIF-1α signal pathway

Esophageal cancer (EC) is the sixth leading cause of cancer-related deaths, and its treatment poses significant challenges. In recent years, photodynamic, photothermal, and chemodynamic therapies have emerged as alternative strategies for tumor intervention. However, limitations such as poor tumor targeting, insufficient microenvironment responsiveness, and unclear mechanisms hinder their application. In this study, we found that hypoxia-inducible factor 1 alpha (HIF-1α) was highly expressed in clinical EC samples, which contributed to tumor malignancy and metastasis. We developed a carbon dots (CDs)-based tumor microenvironment (TME)-responsive nanoplatform, CDs-MnO2-Au-Cet (CMAC), designed for multimodal imaging-guided precision therapy in EC. Both in vitro and in vivo experiments demonstrated that CMAC effectively targeted and imaged EC cells and tissues. CMAC significantly inhibited tumor growth by inducing apoptosis and reducing lung metastasis. Mechanistically, CMAC administration led to a substantial downregulation of HIF-1α and its downstream targets, GLUT1 and MMP9. In summary, we presented a novel nanoplatform for imaging-guided synergistic therapy in EC, which demonstrated excellent anti-tumor growth and metastasis capabilities, along with favorable biocompatibility. This study laid the groundwork for developing innovative theranostic strategies for EC.

Tumor Hypoxia and Radioresistance

Tumor hypoxia is a prevalent feature of solid tumors, significantly contributing to increased tumor aggressiveness, metastatic potential, and resistance to conventional therapies such as radiotherapy. This review explores the complex relationship between tumor hypoxia and radioresistance, highlighting the molecular mechanisms involved and potential therapeutic strategies to enhance radiotherapy efficacy in hypoxic tumors. Key mechanisms include the role of hypoxia-inducible factors (HIFs), particularly HIF-1α, which regulates numerous genes involved in tumor survival, proliferation, and resistance under hypoxic conditions. The review also discusses the oxygen enhancement ratio (OER) and its impact on radiotherapy outcomes, emphasizing how hypoxia leads to reduced radiosensitivity by limiting the formation of radiation-induced DNA damage. Despite the development of various strategies to counteract hypoxia-induced radioresistance, such as HIF inhibitors, hypoxia-targeted gene therapy, and hypoxia-activated prodrugs (HAPs), clinical results have been mixed, necessitating further research. Additionally, advances in imaging techniques for detecting tumor hypoxia are explored, which may allow for more personalized radiotherapy approaches, such as dose painting. The future of overcoming tumor hypoxia in radiotherapy lies in the integration of innovative therapeutic strategies, personalized medicine, and improved imaging technologies, offering hope for enhanced treatment outcomes in cancer patients.

Pediatric patients with von Hippel-Lindau and hemangioblastomas treated successfully with belzutifan.

Hemangioblastoma is the most common tumor associated with von Hippel-Lindau (VHL), and are a leading cause of mortality. We present five pediatric patients with VHL-associated hemangioblastomas treated with belzutifan, a hypoxia-inducible factor 2a (HIF2a) inhibitor. Three patients were started on belzutifan due to vision loss from progressive retinal hemangioblastomas. Within oneyear of treatment, all three patients had improvement in hemangioblastoma size and visual acuity. For patients with intracranial lesions, belzutifan resulted in an improvement in neurologic symptoms and hemangioblastoma size. Four patients experienced grade 1-2 anemia and two patients required a dose reduction. Our report suggests that belzutifan can be an effective therapy for pediatric, adolescent, and young adult patients with VHL-associated hemangioblastomas.

Hypoxia-mediated rescue of retinal ganglion cells deficient in mitochondrial complex I is independent of the hypoxia-inducible factor pathway

Continuous exposure to environmental hypoxia (11% O2) has been shown to markedly slow the progressive degeneration of retinal ganglion cells (RGCs) in a mouse model of mitochondrial optic neuropathy with RGC-specific deletion of the key mitochondrial complex I accessory subunit ndufs4. As a first step toward identifying the therapeutic mechanism of hypoxia in this model, we conducted a series of experiments to investigate the role of the hypoxia-inducible factor (HIF) regulatory pathway in RGC neuroprotection. Vglut2-Cre; ndufs4loxP/loxP mice were crossed with strains bearing floxed alleles of the negative HIF regulatory vhl or of the two major HIF α-subunit isoforms, Hif1α and Hif2α. Deletion of vhl within ndufs4-deficient RGCs failed to prevent RGC degeneration under normoxia, indicating that HIF activation is not sufficient to achieve RGC rescue. Furthermore, the rescue of ndufs4-deficient RGCs by hypoxia remained robust despite genetic inactivation of Hif1α and Hif2α. Our findings demonstrate that the HIF pathway is entirely dispensable to the rescue of RGCs by hypoxia. Future efforts to uncover key HIF-independent molecular pathways induced by hypoxia in this mouse model may be of therapeutic relevance to mitochondrial optic neuropathies such as Leber hereditary optic neuropathy.

Antimetastatic effect of nanodiamond-conjugated quercetin against colon cancer: an in vivo study.

Quercetin (Q) is a compound that can inhibit the growth of cancer cells in the colon; however, to do so, a high dose is needed, requiring a drug delivery system to target cancer endothelial cells directly. This study investigates the potency of nanodiamond-conjugated quercetin (NDQ) as an anticancer drug against colon cancer in Rattus norvegicus induced by N-methyl N-Nitrosourea (MNU). This study is experimental-based and was designed using a six-group treatment method, namely normal control (KN: not treated by MNU, nanodiamond (ND), or Q); negative control (K-: treated by MNU); positive control (K+: treated by MNU and capecitabine); ND (treated by MNU and NDs); Q (treated by MNU and Q); and NDQ (treated by MNU and NDQ). To induce colon cancer in rats, MNU (10 mg/Kg BW) was administrated intrarectally three times per week for four weeks. The treatment of Q (40 mg/Kg BW) or NDQ (40 mg/Kg BW) was given intraperitoneally twice a week for 6 weeks. Cancer progression of all cohorts was evaluated by performing body and colon weight measurements, which involved the following: ELISA assay-specific to metastatic marker matrix metalloprotein-9 (MMP-9), carcinoembryonic antigen (CEA), hypoxia-inducible factor 1 α (HIF1α), vascular endothelial growth factor, protein 53 (p53) and immunohistochemistry staining of Caspase-3 and Ki-67 proteins. Observation of cancer metastasis to the lung was also performed. NDQ significantly inhibited cancer aggressiveness by causing an increment in body weight gain and the growth rate-while reducing the colon weight compared to the K- group. Moreover, decreased levels of MMP-9, CEA, HIF-1α, and Ki67 and increased levels of p53 and Caspase-3 were more significant in the NDQ group than in the Q group. The lung tumor metastases in the NDQ group were fewer than in the K- group. NDQ increased Q's anticancer activity, suggesting that NDs have an effective drug delivery property.

Hypoxia and aging: molecular mechanisms, diseases, and therapeutic targets.

Aging is a complex biological process characterized by the gradual decline of cellular functions, increased susceptibility to diseases, and impaired stress responses. Hypoxia, defined as reduced oxygen availability, is a critical factor that influences aging through molecular pathways involving hypoxia-inducible factors (HIFs), oxidative stress, inflammation, and epigenetic modifications. This review explores the interconnected roles of hypoxia in aging, highlighting how hypoxic conditions exacerbate cellular damage, promote senescence, and contribute to age-related pathologies, including cardiovascular diseases, neurodegenerative disorders, cancer, metabolic dysfunctions, and pulmonary conditions. By examining the molecular mechanisms linking hypoxia to aging, we identify key pathways that serve as potential therapeutic targets. Emerging interventions such as HIF modulators, antioxidants, senolytics, and lifestyle modifications hold promise in mitigating the adverse effects of hypoxia on aging tissues. However, challenges such as the heterogeneity of aging, lack of reliable biomarkers, and safety concerns regarding hypoxia-targeted therapies remain. This review emphasizes the need for personalized approaches and advanced technologies to develop effective antiaging interventions. By integrating current knowledge, this review provides a comprehensive framework that underscores the importance of targeting hypoxia-induced pathways to enhance healthy aging and reduce the burden of age-related diseases.

Clinical significance of HIF-1α, ET-1, and NO as biomarkers in chronic obstructive pulmonary disease patients with pulmonary hypertension.

Pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD), with repeated infections and airflow limitation leading to endothelial dysfunction. The objective of this study was to retrospectively investigate the clinical significance of serum hypoxia-inducible factor 1-alpha (HIF-1α), plasma endothelin-1 (ET-1), and nitric oxide (NO) as non-invasive blood biomarkers for diagnosing patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). A total of 230 AECOPD patients were assessed for serum HIF-1α, plasma ET-1, and NO levels using Doppler echocardiography and blood tests. Clinical characteristics, including age, COPD duration, and comorbidities, were compared between patients with and without PH. The diagnostic value was determined through ROC analysis. Pearson correlation and multivariate logistic analyses explored the correlation of biomarkers in AECOPD with PH. Serum HIF-1α, plasma ET-1, and NO levels showed significant differences between COPD patients with and without PH. The combination model (0.027 * HIF-1α + 0.028 * ET-1 - 0.049 * NO) demonstrated an AUC of 0.89, indicating superior diagnostic value compared to individual biomarkers. Multivariate logistic analysis identified smoking, higher GOLD grade, hypertension, and elevated levels of HIF-1α, ET-1, and NO as independent risk factors for AECOPD. Positive correlations were observed between serum HIF-1α and plasma ET-1 levels with pulmonary artery systolic pressure (PASP), while NO demonstrated a negative correlation. Serum HIF-1α, plasma ET-1, and NO were associated with AECOPD and PH, and detecting individual or combined levels of these biomarkers in the blood can predict COPD-related PH.

USP7 depletion potentiates HIF2α degradation and inhibits clear cell renal cell carcinoma progression

Clear cell renal cell carcinoma (ccRCC) is characterized by Von Hippel Lindau (VHL) gene loss of function mutation, which leads to the accumulation of hypoxia-inducible factor 2α (HIF2α). HIF2α has been well-established as one of the major oncogenic drivers of ccRCC, however, its therapeutic targeting remains a challenge. Through an analysis of proteomic data from ccRCCs and adjacent non-tumor tissues, we herein revealed that Ubiquitin-Specific Peptidase 7 (USP7) was upregulated in tumor tissues, and its depletion by inhibitors or shRNAs caused significant suppression of tumor progression in vitro and in vivo. Mechanistically, USP7 expression is activated by the transcription factors FUBP1 and FUBP3, and it promotes tumor progression mainly by deubiquitinating and stabilizing HIF2α. Moreover, the combination of USP7 inhibitors and afatinib (an ERBB family inhibitor) coordinately induce cell death and tumor suppression. In mechanism, afatinib indirectly inhibits USP7 transcription and accelerates the degradation of HIF2α protein, and the combination of them caused a more profound suppression of HIF2α abundance. These findings reveal a FUBPs-USP7-HIF2α regulatory axis that underlies the progression of ccRCC and provides a rationale for therapeutic targeting of oncogenic HIF2α via combinational treatment of USP7 inhibitor and afatinib.

Pilot Study on the Effect of Patient Condition and Clinical Parameters on Hypoxia-Induced Factor Expression: HIF1A, EPAS1 and HIF3A in Human Colostrum Cells.

Hypoxia-inducible factor 1 (HIF-1) may play a role in mammary gland development, milk production and secretion in mammals. Due to the limited number of scientific reports on the expression of HIF genes in colostrum cells, it was decided to examine the expression of HIF1A, HIF3A and EPAS1 in the these cells, collected from 35 patients who voluntarily agreed to provide their biological material for research, were informed about the purpose of the study and signed a consent to participate in it. The expression of HIF genes was assessed using qPCR. Additionally, the influence of clinical parameters (method of delivery, occurrence of stillbirths in previous pregnancies, BMI level before pregnancy and at the moment of delivery, presence of hypertension during pregnancy, presence of Escherichia coli in vaginal culture, iron supplement and heparin intake during pregnancy) on the gene expression was assessed, revealing statistically significant correlations. The expression of HIF1A was 3.5-fold higher in the case of patients with the presence of E. coli in vaginal culture (p = 0.041) and 2.5 times higher (p = 0.031) in samples from women who used heparin during pregnancy. Approximately 1.7-fold higher expression of the EPAS1 was observed in women who did not supplement iron during pregnancy (p = 0.046). To our knowledge, these are the first studies showing the relationship between HIF expression in cells from breast milk and the method of delivery and health condition of women giving birth. The assessment of HIF expression requires deeper examination in a larger study group, and the results of further studies will allow to determine whether HIF can become biomarkers in pregnancy pathology states.

Serum Levels of the C-terminal Fragment of Fibroblast Growth Factor 23 (C-FGF23) and Hepcidin in Patients with Hemodialysis Undergoing Treatment with a Proline Hydroxylase Domain (PHD) Inhibitor

Background: We previously reported, for the first time, serum levels of the C-terminal fragment of fibroblast growth factor 23 (C-FGF23) in patients undergoing hemodialysis (HD). Most HD patients have undergone treatment with either recombinant erythropoietin (r-EPO) or hypoxia-inducible factor (HIF) proline hydroxylase domain (PHD) inhibitor, both of which stimulate FGF23 production and cleavage. Methods: This cross-sectional observational study involved analyzing measuring FGF-related parameters and comparing results for subgroups of patients who received either r-EPO and or a PHD inhibitor. Results: No significant difference was observed for iron-related parameters or serum hepcidin levels in both subgroups of patients. Significant differences were found for certain FGF-23-related parameters. Conclusion: Both FGF23 production and cleavage were stimulated more in patients treated with the PHD inhibitor than in patients treated with r-EPO.

ALKBH4 functions as a hypoxia-responsive tumor suppressor and inhibits metastasis and tumorigenesis.

The human AlkB homolog (ALKBH) dioxygenase superfamily plays a crucial role in gene regulation and is implicated in cancer progression. Under hypoxic conditions, hypoxia-inducible factors (HIFs) dynamically regulate methylation by controlling various dioxygenases, thereby modulating gene expression. However, the role of hypoxia-responsive AlkB dioxygenase remains unclear. The molecular events were examined using real-time PCR and Western blot analysis. Tumor cell aggressiveness was evaluated through migration, invasion, MTT, trypan blue exclusion, and colony formation assays. In vivo metastatic models and xenograft experiments were conducted to evaluate tumor progression. Here, we examined the expression of the ALKBH superfamily under hypoxic conditions and found that ALKBH4 expression was negatively regulated by hypoxia. Knockdown of ALKBH4 enhanced the epithelial-mesenchymal transition (EMT), cell migration, invasion, and growth in vitro. The silencing of ALKBH4 enhanced metastatic ability and tumor growth in vivo. Conversely, overexpression of ALLKBH4 reversed these observations. Furthermore, overexpression of ALKBH4 significantly reversed hypoxia/HIF-1α-induced EMT, cell migration, invasion, tumor metastasis, and tumorigenicity. Notably, high expression of ALKBH4 was associated with better outcomes in head and neck cancer and breast cancer patients. Enrichment analysis also revealed that ALKBH4 was negatively enriched in hypoxia-related pathways. Clinically, a negative correlation between ALKBH4 and HIF-1α protein expression has been observed in tissues from both head and neck cancers and breast cancers. These findings collectively suggest that ALKBH4 acts as a tumor suppressor and holds therapeutic potential for hypoxic tumors.

Plasmodium infection downregulates hypoxia‑inducible factor 1α expression to suppress the vascularization and tumorigenesis of liver cancer.

Liver cancer is characterized by hypervascularization. Anti-angiogenic agents may normalize the tumor vasculature and improve the efficacy of other treatments. The present study aims to investigate the anti-angiogenic effect of Plasmodium infection in a mouse model of implanted liver cancer cells. HepG2 cells were injected into the left liver lobe of nude mice as a model of in situ hepatic tumorigenesis. Plasmodium yoelii parasitized erythrocytes were administered in the animal model of liver cancer to introduce Plasmodium infection. The tumor growth and microvascular density were determined in the presence or absence of Plasmodium infection. The expression levels of hypoxia-inducible factor 1α (HIF-1α) and angiogenesis-related factors were evaluated using western blotting and reverse transcription-quantitative PCR analysis. The results demonstrated that Plasmodium infection suppressed tumor growth and vascularization in the mouse model of implanted HepG2 cells. Plasmodium parasites reduced the expression of pro-angiogenic factors (vascular endothelial growth factor A and angiopoietin 2), matrix metalloproteinases [(MMP)2 and MMP9] and inflammatory cytokines [tumor necrosis factor α, interleukin 6 (IL)-6) and IL-1β] in both hepatic and tumor tissues. HIF-1α was downregulated in both hepatic and tumor tissues upon Plasmodium infection, and HIF-1α overexpression rescued angiogenesis and tumor growth under the condition of Plasmodium infection. In conclusion, the results of the present study demonstrated the anti-angiogenic and anti-tumorigenic effects of Plasmodium infection on liver cancer through downregulating HIF-1α expression, indicating that Plasmodium parasites could be developed as an intervention strategy to restrain neo-angiogenesis in liver cancer.

EGCG enhances antitumor effect of apatinib in nonsmall cell lung cancer by targeting VEGF signaling to inhibit glycolysis.

Nonsmall cell lung cancer (NSCLC), one of the most aggressive malignancies globally, is characterized by poor prognosis and limited life expectancy. Epigallocatechin-3-gallate (EGCG), a natural polyphenol found in green tea, has emerged as a promising anticancer agent due to its potent antitumor properties. However, the role and the underlying mechanisms of EGCG in NSCLC remain poorly understood. Hence, this research aimed to explore the effect of EGCG on the antitumor effect of apatinib in NSCLC throughvascular endothelial growth factor(VEGF)-regulated glycolysis. Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine staining, wound healing, transwell, terminal deoxynucleotidyl transferase dUTP nick-end labeling, and flow cytometry assays were carried out to evaluate the proliferation, migration, invasion, and apoptosis of H1299 cells, respectively. Furthermore, western blot analysis was used to detect the expressions of VEGF, p-vascular endothelial growth factor receptor-2, hypoxia-inducible factor 1α, neuropilin-1, phosphorylated-phosphatidylinositol 3-kinase, and phosphorylated-AKT. The transfection efficiency of H1299 cells with VEGF overexpression plasmid was also assessed by western blot analysis. Glycolysis was analyzed by estimating extracellular acidification rate, lactate concentration, glucose uptake, and the expressions of lactate dehydrogenase A, pyruvate kinase M2, and hexokinase 2. The results demonstrated that VEGF activated glycolysis in NSCLC cells. EGCG alone and apatinib alone or in combination inhibited cell viability, proliferation, invasion, migration, and glycolysis whereas promoted apoptosis in NSCLC cells. EGCG regulated glycolysis levels in NSCLC through VEGF overexpression, and enhanced the antitumor effect of apatinib in NSCLC through VEGF-regulated glycolysis. Taken together, EGCG strengthened the protective effects of apatinib in NSCLC through glycolysis mediated by VEGF.

Prognostic Impact of H19/Cell Adhesion Molecules Circuitry on Prostate Cancer Biopsy.

Metastatic prostate cancer (PCa) presents a significant challenge in oncology due to its high mortality rate and the absence of effective biomarkers for predicting patient outcomes. Building on previous research that highlighted the critical role of the long noncoding RNA (lncRNA) H19 and cell adhesion molecules in promoting tumor progression under hypoxia and estrogen stimulation, this study aimed to assess the potential of these components as prognostic biomarkers for PCa at the biopsy stage. This research utilized immunohistochemistry and droplet digital PCR to analyze formalin-fixed paraffin-embedded (FFPE) biopsies, focusing on specific markers within the H19/cell adhesion molecules pathway. A novel multivariate analysis led to a "BioScore", a composite biomarker score to predict disease progression. This score is based on evaluating five key markers: the expression levels of Hypoxia-Inducible Factor 2 Alpha (HIF-2α), endothelial Nitric Oxide Synthase (eNOS), β4 integrin, E-cadherin transcript (CDH1), and lncRNA H19. The criteria for the "BioScore" involve identifying three out of these five markers, combining elevated levels of HIF-2α, eNOS, β4 integrin, and CDH1 with reduced H19 expression. This finding suggests the possibility of identifying, at the time of biopsy, PCa patients at higher risk of metastasis based on dysregulation in the H19/cell adhesion molecules circuitry. This study provides a valuable opportunity for early intervention in managing PCa, potentially contributing to personalized treatment strategies.