HIF-1α signaling: Essential roles in tumorigenesis and implications in targeted therapies

Untargeted LC-MS/MS- based metabolomics profiling of colorectal cancer cell lines reveals potential hypoxia-associated biomarkers

Colorectal cancer (CRC), a common cancer of the large intestine, is influenced by metabolic reprogramming due to hypoxia. Novel biomarkers may be identified through metabolomics. While many CRC studies have reported metabolomic profiling, the metabolic profile of CRC in the context of oxygen content has yet to be elucidated. Comprehending the metabolic alterations in cancer cells transitioning from normoxia (NMX) to hypoxia (HPX) and anoxia (ANX) is essential for the formulation of drugs that target particular metabolic pathways. Our study aimed to find metabolic changes in the HCT-116 CRC cell line under ANX, HPX, and NMX conditions, as well as to investigate novel biomarkers for CRC utilizing liquid chromatography-mass spectrometry (LC-MS/MS) based metabolomics approaches. Our findings showed significant changes in 77 metabolites in HCT-116 CRC cells across ANX, HPX, and NMX conditions, with 34 metabolites significantly disrupted in HPX compared to NMX, and 64 metabolites significantly changed in HPX compared to ANX. Significant differences included glutathione, gamma-glutamylcysteine, glycerophosphocholine, adenosine monophosphate, 5'-methylthioadenosine, guanosine 5'-diphosphate, threonic acid, and L-acetylcarnitine. Comprehending the metabolic changes in HPX, ANX, and NMX may uncover new pathways that could be targeted for potential treatments.

Unveiling EIF5A2: A multifaceted player in cellular regulation, tumorigenesis and drug resistance

The eukaryotic initiation factor 5A2 gene (EIF5A2) is a highly conserved and multifunctional gene that significantly influences various cellular processes, including translation elongation, RNA binding, ribosome binding, protein binding and post-translational modifications. Overexpression of EIF5A2 is frequently observed in multiple cancers, where it functions as an oncoprotein. Additionally, EIF5A2 is implicated in drug resistance through the regulation of various molecular pathways. In the review, we describe the structure and functions of EIF5A2 in normal cells and its role in tumorigenesis. We also elucidate the molecular mechanisms associated with EIF5A2 in the context of tumorigenesis and drug resistance. We propose that the biological roles of EIF5A2 in regulating diverse cellular processes and tumorigenesis are clinically significant and warrant further investigation.

Qideng Mingmu Capsules Ameliorates Retinal Neovascularization by Regulating Ang/Tie2 Signaling Pathway

OBJECTIVE

To investigate the inhibitory effects and underlying mechanisms of Qideng Mingmu Capsules (QD) on retinal neovascularization (RNV).

METHODS

Seven-day-old C57BL/6J mice were assigned to the following groups: control, oxygen-induced retinopathy (OIR), low-, medium-, high-dose QD (225, 450, and 900 mg/g daily), and angiopoietin 1 (Ang1), 20 mice in each group. Except for the control group, an OIR model was induced by exposing mice to a hyperoxic environment for 5 d (postnatal days 7-12), followed by a normoxic environment for 5 d (postnatal days 12-17). From day 12, the treatment groups received QD orally or Ang1 via binocular intravitreal injection. On day 17, hematoxylin and eosin staining and fluorescein isothiocyanate-dextran staining were performed to evaluate RNV growth. Immunofluorescence staining, immunohistochemistry, and Western blotting were used to analyze the expressions of Ang/tyrosine kinase with immunoglobulin and epidermal growth factor homology domain-2 (Tie2) signaling pathway, hypoxia-inducible factor-1α (HIF-1α), and retinal vascular maturation markers. In addition, the effects of QD on the viability of rat retinal microvascular endothelial cells (rRMECs) was assessed.

RESULTS

QD significantly inhibited RNV formation, reduced RNV density, increased the expressions of Ang1, Tie2, and phosphorylated protein kinase B, and decreased the expression of Ang2 (P<0.05 or P<0.01). QD also enhanced retinal vascular pericyte coverage, reduced HIF-1α expression, and increased vascular endothelial cadherin levels (P<0.05 or P<0.01). Furthermore, no adverse effects were observed on the viability of rRMECs after QD intervention.

CONCLUSIONS

QD effectively inhibited RNV formation, promoted neovascular maturation and remodeling, and protected retinal function by modulating the Ang/Tie2 signaling pathway. Therefore, QD may serve as a promising therapeutic option for retinal neovascular diseases.

Co-expression of HIF1A with multi-drug transporters (P-GP, MRP1, and BCRP) in chemoresistant breast, colorectal, and ovarian cancer cells

Therapeutic resistance poses a significant challenge in treating most cancers and often leads to poor clinical outcomes and even treatment failure. One of the primary mechanisms that confer multidrug resistance phenotype to cancer cells is the hyperactivity of certain drug efflux transporters. P-GP, MRP1, and BCRP are the key ABC efflux pumps that collectively extrude a broad spectrum of chemotherapeutic drugs. Besides, HIF1A, a master transcription regulatory protein, is also associated with cancer development and therapeutic resistance. Thereby, this study aimed to delve into the mechanisms of drug resistance, specifically focusing on HIF1A-driven overexpression of ABC transporters. A total of 57 chemoresistant and 57 paired control tissue samples (breast, colorectal, and ovarian) from Bangladeshi cancer patients were analyzed to determine the co-expression level of ABC transporters and HIF1A. Molecular docking was also conducted to evaluate the interactions of HIF1A protein and hypoxia response element (HRE) sequences in the promoter regions transporter genes. This study revealed that HIF1A is significantly overexpressed in chemoresistant tissues, suggesting its pivotal role in chemoresistance mechanisms across malignancies and its potential as a target to overcome therapeutic resistance. The findings from this study also suggest a direct upregulation of ABCB1, ABCC1, and ABCG2 transcription by HIF1A in chemoresistant cancer cells by binding to the HRE sequence in the promoter regions. Thus, inhibition of these interactions of HIF1A appears to be a promising approach to reverse chemoresistance. The findings of this study can serve as a foundation for future research, resolving molecular intricacies to improve treatment outcomes in chemoresistant patients.

Effect of deubiquitinases in head and neck squamous cell carcinoma (Review)

HNSCC includes nasopharyngeal, laryngeal and oral cancers, and its pathogenesis is influenced by various factors. As an essential part of the ubiquitin (Ub)-proteasome system (UPS), deubiquitinating enzymes (DUBs) maintain the homeostasis of Ub molecules and influence the physiological functions of cells and disease processes by removing ubiquitinated proteins. Accumulating evidence has confirmed that the aberrant expression of DUBs is involved in cell proliferation, metastasis, and apoptosis during the development of HNSCC, with some acting as oncogenes and others as tumor-suppressor genes. In this review, the DUBs implicated in HNSCC were summarized and the mechanisms underlying abnormal DUBs expression in signaling pathways were discussed. In addition, given the important role of DUBs in tumorigenesis, recent studies were reviewed and agonists and inhibitors of DUBs were summarized to identify more effective therapeutic strategies.

Inhibition of MCP1 (CCL2) Enhances Antitumor Activity of NK Cells Against HCC Cells Under Hypoxia

Hypoxia, a low-oxygen state, is a common feature of solid tumors. MCP1 (CCL2) is a small cytokine that is closely related to hypoxia and has a positive effect on tumor development. Hypoxia causes resistance to various treatments for solid tumors and the evasion of cancer immune surveillance by lymphocytes. Natural killer (NK) cells are innate lymphocytes that play an important role in cancer development, particularly in the liver. First, it was found that the incubation of HCC in hypoxia (2-5% O2) significantly increased the production of several inflammatory cytokines, including MCP1, compared to that of normal oxygen (20% O2). Subsequently, blocking MCP1 with an anti-MCP1 antibody in HCC cultures inhibited the growth and migration of HCC cells in vitro and in vivo. This was associated with a decrease in the expression of HIF-1α/STAT3 in HCC under hypoxia. Furthermore, blocking MCP1 in HCC cell cultures under hypoxia significantly increased the chemotaxis and activation of NK-92 cells against HCC cells. MCP1 blockade in HCC cell cultures under hypoxia induced a shift in NK cells to the CD56+dim population and an increase in the expression of the activation receptors NKG2D and NKp44. In conclusion, modulation of MCP1 could enhance NK activity against hypoxic HCC cells.

Hypoxia-driven angiogenesis and metabolic reprogramming in vascular tumors

Hypoxia is a hallmark of the tumor microenvironment (TME), and it plays a crucial role in the occurrence and progression in vascular tumors. Under hypoxic conditions, hypoxia-inducible factor 1-alpha (HIF-1α) is stabilized, inducing changes in the expression of various target genes involved in angiogenesis, metabolism, and cell survival. This includes the upregulation of pro-angiogenic factors like VEGF, which promotes the formation of dysfunctional blood vessels, contributing to the worsening of the hypoxic microenvironment. At the same time, hypoxia induces a metabolic shift toward glycolysis, even in the presence of oxygen, supporting tumor cell survival and proliferation by providing necessary energy and biosynthetic precursors. This review discusses the molecular mechanisms by which hypoxia regulates angiogenesis and metabolic reprogramming in vascular tumors, highlighting the intricate link between these processes, and explores potential therapeutic strategies to target these pathways in order to develop effective treatment strategies for patients.

AQP9 weakens the cytotoxicity of CD8+ T cells in colon adenocarcinoma by boosting M2 polarization of macrophages under hypoxia conditions

BACKGROUND

Colon adenocarcinoma (COAD) is a leading cause of cancer mortality, with Aquaporin 9 (AQP9) implicated in its progression. M2 macrophages in the tumor microenvironment (TME) promote cancer metastasis, but the role of AQP9 on M2 macrophages remains unelucidated.

RESEARCH DESIGN AND METHODS

Using COAD cell lines, AQP9 expression was analyzed via RT-qPCR and Western blot (WB). Hypoxic conditions were simulated to assess HIF-1α and AQP9 interactions through ChIP and dual-luciferase assays. AQP9 knockdown effects on proliferation/migration were tested via colony formation and wound healing. M2 macrophage polarization and CD8+ T cell cytotoxicity were evaluated using flow cytometry, ELISA, and IHC in co-culture systems.

RESULTS

AQP9 was upregulated in COAD and correlated with poor prognosis. After AQP9 in COAD cells was knocked down, the abilities of tumor cells to migrate and proliferate were dampened. Hypoxia upregulated HIF-1α, which transcriptionally activated AQP9. Knocking down AQP9 repressed the M2 polarization of macrophages, thereby reinforcing the cytotoxicity of CD8+ T cells. No adverse events were reported in vitro.

CONCLUSION

AQP9 promotes COAD progression by driving HIF-1α-mediated M2 polarization, impairing CD8+ T cell function. Key limitations include the lack of in vivo validation and clinical cohort analysis.

Integrated proteomic network analysis reveals PTPRC as a central hub protein orchestrating co-expression modules and metabolic dysregulation in renal carcinoma: PTPRC protein molecular action

The occurrence of renal carcinoma is closely related to a variety of molecular mechanisms and metabolic disorders. PTPRC (protein tyrosine phosphatase receptor C), as an important regulatory protein, was studied to reveal the role of PTPRC in renal carcinoma through comprehensive proteomic network analysis, especially its core position in the coordination of co-expression modules and metabolic disorders. This study was the first to download and process multiple publicly available renal cancer transcriptome data to conduct differential gene expression analysis across datasets. Functional enrichment and disease ontology analysis were performed on the transcriptome of renal cancer, and weighted gene co-expression network (WGCNA) was constructed. The results showed that comprehensive principal component analysis revealed significant differences in the transcriptome of renal cancer, and functional annotation revealed specific pathways associated with renal cancer. WGCNA analysis identified tumor-associated co-expression modules, while multi-omics analysis further identified core regulatory networks including PTPRC. As a central hub protein, PTPRC plays an important coordinating role in the co-expression module and metabolic dysregulation of renal carcinoma. This discovery provides a new perspective for understanding the molecular mechanism of kidney cancer.

Nanotherapeutic Formulations for the Delivery of Cancer Antiangiogenics

Antiangiogenic medications for cancer treatment have generally failed in showing substantial benefits in terms of prolonging life on their own; their effects are noticeable only when combined with chemotherapy. Moreover, treatments based on prolonged antiangiogenics administration have demonstrated to be ineffective in stopping tumor progression. In this scenario, nanotherapeutics can address certain issues linked to existing antiangiogenic treatments. More specifically, they can provide the ability to target the tumor's blood vessels to enhance drug accumulation and manage release, ultimately decreasing undesired side effects. Additionally, they enable the administration of multiple angiogenesis inhibitors at the same time as chemotherapy. Key reports in this field include the design of polymeric nanoparticles, inorganic nanoparticles, vesicles, and hydrogels for loading antiangiogenic substances like endostatin and interleukin-12. Furthermore, nanoformulations have been proposed to efficiently control relevant pro-angiogenic pathways such as VEGF, Tie2/Angiopoietin-1, HIF-1α/HIF-2α, and TGF-β, providing powerful approaches to block tumor growth and metastasis. In this article, we outline a selection of nanoformulations for antiangiogenic treatments for cancer that have been developed in the past ten years.

Role of lysine lactylation in neoplastic and inflammatory pulmonary diseases (Review)

Protein lysine lactylation is a ubiquitous and post‑translational modification of lysine residues that involves the addition of a lactyl group on both histone and non‑histone proteins. This process plays a pivotal role in human health and disease and was first discovered in 2019. This epigenetic modification regulates gene transcription from chromatin or directly influences non‑histone proteins by modulating protein‑DNA/protein interactions, activity and stability. The dual functions of lactylation in both histone and non‑histone proteins establish it as a crucial mechanism involved in various cellular processes, such as cell proliferation, differentiation, immune and inflammatory responses and metabolism. Specific enzymes, referred to as 'writers' and 'erasers', catalyze the addition or removal of lactyl groups at designated lysine sites, thereby dynamically modulating lactylation through alterations in their enzymatic activities. The respiratory system has a remarkably intricate metabolic profile. Numerous pulmonary diseases feature an atypical transition towards glycolytic metabolism, which is linked to an overproduction of lactate, a possible substrate for lactylation. However, there has yet to be a comprehensive review elucidating the full impact of lactylation on the onset, progression and potential treatment of neoplastic and inflammatory pulmonary diseases. In the present review, an extensive overview of the discovery of lactylation and advancements in research on the existing lactylation sites were discussed. Furthermore, the review particularly investigated the potential roles and mechanisms of histone and non‑histone lactylation in various neoplastic and inflammatory pulmonary diseases, including non‑small cell lung cancers, malignant pleural effusion, pulmonary fibrosis, acute lung injury and asthma, to excavate the new therapeutic effects of post‑translational modification on various pulmonary diseases.

MSNs-loaded HMME and Erastin-mediated ferroptosis combined with sonodynamic therapy for HCC treatment

BACKGROUND

Ferroptosis can have a major impact on the development and advancement of hepatocellular carcinoma (HCC) due to its clear association with heightened vulnerability to the disease. This study aimed to develop a novel nanoplatform to evaluate its effectiveness in in vivo and in vitro models of HCC.

METHODS

Erastin, a compound that induces iron-dependent cell death, and HMME, a sonosensitizer, were enclosed within mesoporous silica nanoparticles (MSNs). The nanoparticles were engineered to exhibit a responsive assembly-disassembly mechanism. Hydrophilic hyaluronic acid (HA) was utilized for conjugation modification to synthesize Erastin/HMME@MSNs-HA. In vivo and in vitro experiments were conducted to elucidate the antitumor mechanisms of this nanomaterial.

RESULTS

In the in vitro cellular experiments, Erastin/HMME@MSNs-HA was rapidly degraded by hyaluronidase, leading to increased endocytosis of the cancer cells. Cellular breakdown led to the generation of harmful reactive oxygen species (ROS), decreased glutathione levels, and increased lipid peroxidation, resulting in a decrease in mitochondrial membrane potential, dysfunctional mitochondria, reduced cell growth, and increased cell death. Additionally, the Erastin/HMME@MSNs-HA nanotherapy platform, when combined with ultrasound (US) treatment, exhibited significant therapeutic effectiveness against tumors in vivo. It induced significant cell death in cancerous tissues, decreased tumor growth, worsened tissue oxygen deprivation, and exhibited good compatibility with the body.

CONCLUSION

These findings indicate that the nanoplatform can effectively alleviate tumor hypoxia while inducing apoptosis and ferroptosis, laying the foundation for enhancing the efficacy of ROS-mediated HCC therapy.

A comprehensive analysis of deubiquitinase USP20 on prognosis and immunity in pan-cancer

USP20 is a deubiquitinase enzyme in the ubiquitin-proteasome system that plays a role in the development and progression of tumors. However, the relationships between USP20 expression and clinical prognosis and tumor immunity remain unclear. In this study, the USP20 expression and its relationships with potential prognostic value, the tumor microenvironment (TME), immune-related genes, the tumor mutational burden (TMB), microsatellite instability (MSI), homologous recombination deficiency, cancer stemness, and correlated signaling pathways were investigated via The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Cancer Cell Line Encyclopedia (CCLE), STRING, Gene Expression Profiling Interactive Analysis (GEPIA2), and the Human Protein Atlas (HPA). Moreover, we explored the oncogenic capability of USP20 in breast cancer. Data analysis was performed via GraphPad Prism and the R package. The results indicated that the expression of USP20 was upregulated in most cancers and was associated with survival in 17 tumor types. Furthermore, USP20 expression was strongly correlated with immune infiltration and the expression of immunomodulatory genes. We also verified the correlations between USP20 expression and tumor heterogeneity, cancer stemness, and the corresponding signaling pathways. Moreover, our work revealed that USP20 was highly expressed and predicted a poor outcome in patients with breast cancer. Basic experiments verified that USP20 overexpression promoted both the proliferation and migration of breast cancer cells. This study comprehensively investigated the expression of USP20 and its correlation with clinical prognostic assessment and tumor immune modulation across cancers, indicating that USP20 might have utility as a biomarker associated with prognosis and cancer immunotherapy.

Regulation of Erythropoietin Activity in Clear Renal Cell Carcinoma

Clear-cell renal cell carcinoma (ccRCC) is associated with the mutated von Hippel-Lindau (VHL) gene leading to the activation of hypoxia-inducible factor 1A (HIF1A) and subsequent overexpression of erythropoietin (EPO). We analyzed tumor and healthy tissues from 43 ccRCC patients after radical nephrectomy and cultured 786-O (biallelic VHL inactivation) and Caki-1 (wild-type VHL) cells in normal (21% O2) and low oxygen (3% O2) with 10% and 2% fetal bovine serum (FBS). DNA sequencing, including Sanger sequencing, MLPA and LOH, revealed 27 somatic mutations of VHL in ccRCC. HIF1A protein showed decreased or no expression in tumors compared to healthy tissue, independent of VHL alteration. The 786-O cells showed increased HIF1A protein expression after 48 h under low oxygen and 10% FBS. EPO and erythropoietin receptor (EPOR) were significantly decreased in ccRCC without HIF1A expression. EPO mRNA increased in the 786-O cells at 3% O2 after 48 h, while the Caki-1 cells had low or no EPO expression. Hypoxia increased EPOR mRNA in the Caki-1 cells at 10% FBS, but decreased in the 786-O cells at 2% FBS after 48 h. JAK2/STAT5A activity was increased only in HIF1A-positive tumors. These results suggest that EPO/EPOR activation in ccRCC is mainly driven by low oxygen, not VHL regulation of hypoxia-related responses.

Tβ4-exosome-loaded hemostatic and antibacterial hydrogel to improve vascular regeneration and modulate macrophage polarization for diabetic wound treatment

Diabetic wounds often exhibit delayed healing due to compromised vascular function and intensified inflammation. In this study, we overexpressed Thymosin β4 (Tβ4) in Adipose-Derived Stem Cells (ADSCs) to produce Exosomes (Exos) rich in Tβ4. We then utilized a dual photopolymerizable hydrogel composed of Hyaluronic Acid Methacryloyl (HAMA) and Poly-L-lysine Methacryloyl (PLMA) for the sustained release of Tβ4-Exos on diabetic wounds. The results showed that Tβ4-Exos could stimulate angiogenesis and collagen synthesis, and mitigate inflammation in diabetic wounds by promoting the polarization of M1-type macrophages and inhibiting that of M2-type macrophages. Furthermore, Tβ4-Exos was found to activate the PI3K/AKT/mTOR/HIF-1a signaling pathway, thereby enhancing vascular proliferation. In summary, the sustained release of Tβ4-Exos in HAMA-PLMA (HP) hydrogel and the management of inflammation through the upregulation of the HIF-1a pathway and modulation of macrophage polarization in vascular proliferation significantly accelerated the healing process of diabetic wounds.

Knockdown of EBP1 promotes doxorubicin-induced apoptosis in renal clear cell carcinoma cells through activation of the p38/HIF-1α pathway

Kidney clear cell carcinoma (KIRC) is a prevalent urological cancer. Despite substantial improvements in KIRC care, patients with intermediate and advanced stages of the disease lack access to appropriate medications. Doxorubicin is widely used as a chemotherapy drug for the treatment of multiple types of cancer. However, its use is associated with harmful side effects and drug resistance. ErbB3-binding protein (EBP1) is highly expressed in KIRC, and the knockdown of EBP1 reduces the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) and the expression of HIF-1α. Therefore, the present study aimed to evaluate the effectiveness of combined doxorubicin administration and EBP1 knockdown in KIRC cell lines. The KIRC cell lines 786-O and 769-P were used for the experiments, and short hairpin RNA technology was employed to specifically knock down the expression of the EBP1 gene. After treatment, cells were analyzed by western blotting to detect changes in p38MAPK phosphorylation levels and HIF-1α expression. The results showed that EBP1 knockdown significantly enhanced the antitumor effect of doxorubicin on KIRC cells through the p38MAPK/HIF-1α pathway. In conclusion, the knockdown of EBP1 in combination with doxorubicin may be a potential strategy for the treatment of KIRC.

Selective targeting of genes regulated by zinc finger proteins in endometriosis and endometrioid adenocarcinoma by zinc niflumato complex with neocuproine

Inadequate angiogenesis of endometriotic implants stimulated by the inflammatory microenvironment in the uterine region leads to the development of gynecological diseases, which significantly reduce the fertility and vitality of young women. Angiogenic processes are controlled by factors whose activities are regulated at the gene level by reactive oxygen species (ROS), hypoxia-induced factors (HIFs), and zinc-finger proteins (ZnFs) or posttranscriptionally via non-coding RNAs. The cooperation of these factors is responsible for the manifestation of pathological stimuli in the form of endometriosis of the body of the uterus, ovaries, or peritoneum, from which endometrioid carcinoma can develop. Molecules that can control gene expression by their intercalation to target DNA sequence, such as [Zn(neo)(nif)2], could prevent the hyperactivation of pro-angiogenic pathways (decrease HIF-1α, VEGF-A, TGF-β1, COX2, and ANG2/ANG1), reduce the formation of ROS, and reduce the risk of uterine neoplasticity. The NSAID-metal complex [Zn(neo)(nif)2] shows an ability to intercalate into ZNF3-7 target DNA sequence at a higher rate, which could explain its effect on genes regulated by this transcription factor. In addition, [Zn(neo)(nif)2] affects ROS production and Ca2+ level, possibly pointing to mitochondrial dysfunction as a potential cause for the described apoptosis.

Recent Update of Natural Compounds as HIF-1α Inhibitors in Colorectal Carcinoma

Hypoxia-inducible factor (HIF)-1 is a transcription factor that regulates the expression of target genes associated with oxygen homeostasis under hypoxic conditions, thereby contributing to tumor development and progression. Accumulating evidence has demonstrated that HIF-1α mediates different biological processes, including tumor angiogenesis, metastasis, metabolism, and immune evasion. Thus, overexpression of HIF-1α is strongly associated with poor prognosis in cancer patients. Natural compounds are important sources of anticancer drugs and studies have emphasized the decisive role of these mediators in modulating HIF-1α. Therefore, the pharmacological targeting of HIF-1α has emerged as a novel cancer therapeutic approach in recent years. The novelty of this review is that it summarizes natural products targeting HIF-1α in colorectal cancer that have not been presented earlier. We studied research publications related to the HIF-1α domain in cancer from 2010 to 2024. However, our main focus was to identify a better targeted approach for colorectal carcinoma management. Our review described HIF-1α role in tumor progression, summarizes the natural compounds employed as HIF-1α inhibitors, and discusses their potential in the development of natural compounds as HIF-1α inhibitors for colorectal cancer treatment.

The Role of Hypoxia-Inducible Factor-1α (HIF-1α) in the Progression of Ovarian Cancer: Perspectives on Female Infertility

Hypoxia-Inducible Factor-1α (HIF-1α) is crucial in the progression of ovarian cancer, especially in influencing its tumor microenvironment and promoting pathogenic pathways that worsen female infertility. In hypoxic settings, HIF-1α is stabilized and activates the transcription of genes associated with angiogenesis, metabolic reprogramming, epithelial-to-mesenchymal transition, and therapeutic resistance. Angiogenesis and glycolytic reprogramming mediated by HIF-1 tumor proliferation, survival, and metastasis. Its dysfunction concurrently impairs ovarian homeostasis, undermining follicular growth, hormone synthesis, and the ovarian vascular network, consequently contributing to infertility. Moreover, HIF-1α induces persistent inflammation and oxidative stress, promoting an environment damaging to reproductive health. Due to its dual function in ovarian cancer growth and infertility, HIF-1α is a potential therapeutic target. Strategies including small molecule inhibitors and nanoparticle-mediated delivery of drugs possess the potential to reduce HIF-1α activity, hence reducing cancer progression while protecting fertility. This review seeks to clarify the molecular basis of HIF-1α in ovarian cancer and its effects on female infertility, providing insights into novel treatment approaches that target both controlling the disease and preserving fertility.

Epigenetic regulatory protein chromobox family regulates multiple signalling pathways and mechanisms in cancer

Signal transduction plays a pivotal role in modulating a myriad of critical processes, including the tumour microenvironment (TME), cell cycle arrest, proliferation and apoptosis of tumour cells, as well as their migration, invasion, and the epithelial-mesenchymal transition (EMT). Epigenetic mechanisms are instrumental in the genesis and progression of tumours. The Chromobox (CBX) family proteins, which serve as significant epigenetic regulators, exhibit tumour-specific expression patterns and biological functionalities. These proteins are influenced by a multitude of factors and could modulate the activation of diverse signalling pathways within tumour cells through alterations in epigenetic modifications, thereby acting as either oncogenic agents or tumour suppressors. This review aims to succinctly delineate the composition, structure, function, and expression of CBXs within tumour cells, with an emphasis on synthesizing and deliberating the CBXs-mediated activation of intracellular signalling pathways and the intricate mechanisms governing tumourigenesis and progression. Moreover, a plethora of contemporary studies have substantiated that CBXs might represent a promising target for the diagnosis and therapeutic intervention of tumour patients. We have also compiled and scrutinized the current research landscape concerning inhibitors targeting CBXs, aspiring to aid researchers in gaining a deeper comprehension of the biological roles and mechanisms of CBXs in the malignant evolution of tumours, and to furnish novel perspectives for the innovation of targeted tumour therapeutics.

Circadian rhythm, hypoxia, and cellular senescence: From molecular mechanisms to targeted strategies

Cellular senescence precipitates a decline in physiological activities and metabolic functions, often accompanied by heightened inflammatory responses, diminished immune function, and impaired tissue and organ performance. Despite extensive research, the mechanisms underpinning cellular senescence remain incompletely elucidated. Emerging evidence implicates circadian rhythm and hypoxia as pivotal factors in cellular senescence. Circadian proteins are central to the molecular mechanism governing circadian rhythm, which regulates homeostasis throughout the body. These proteins mediate responses to hypoxic stress and influence the progression of cellular senescence, with protein Brain and muscle arnt-like 1 (BMAL1 or Arntl) playing a prominent role. Hypoxia-inducible factor-1α (HIF-1α), a key regulator of oxygen homeostasis within the cellular microenvironment, orchestrates the transcription of genes involved in various physiological processes. HIF-1α not only impacts normal circadian rhythm functions but also can induce or inhibit cellular senescence. Notably, HIF-1α may aberrantly interact with BMAL1, forming the HIF-1α-BMAL1 heterodimer, which can instigate multiple physiological dysfunctions. This heterodimer is hypothesized to modulate cellular senescence by affecting the molecular mechanism of circadian rhythm and hypoxia signaling pathways. In this review, we elucidate the intricate relationships among circadian rhythm, hypoxia, and cellular senescence. We synthesize diverse evidence to discuss their underlying mechanisms and identify novel therapeutic targets to address cellular senescence. Additionally, we discuss current challenges and suggest potential directions for future research. This work aims to deepen our understanding of the interplay between circadian rhythm, hypoxia, and cellular senescence, ultimately facilitating the development of therapeutic strategies for aging and related diseases.

Emerging Role of Hypoxia-Inducible Factors (HIFs) in Modulating Autophagy: Perspectives on Cancer Therapy

Hypoxia-inducible factors (HIFs) are master regulators of cellular responses to low oxygen levels and modulate autophagy, a conserved process essential for maintaining homeostasis. Under hypoxic conditions, HIFs regulate the expression of autophagy-related genes and influence autophagic flux and cellular stress responses. Dysregulated hypoxia-induced autophagy promotes cancer cell survival, metabolism, and metastasis, thereby contributing to treatment resistance. Targeting HIF-mediated pathways or modulating autophagic processes offers the potential to improve traditional cancer therapies and overcome drug resistance. Pharmacological inhibitors of HIFs or autophagy, either alone or in combination with other treatments, may disrupt the pro-survival mechanisms within the hypoxic tumor microenvironment. Further research is needed to elucidate the intricate interplay between HIF signaling and the autophagy machinery in cancer cells. Understanding these processes could pave the way for novel therapeutic strategies to enhance treatment outcomes and combat drug resistance. This review highlights the complex relationship between HIFs and autophagy in cancer development and therapy, offering insights into how targeting these pathways may improve patient outcomes.

Whole-body vibration protects against chronic high-altitude hypoxic bone loss by regulating the nitric oxide/HIF-1α axis in osteoblasts

The hypobaric hypoxia environment found at high altitudes imposes various reversible and irreversible detrimental effects on living organisms. Accumulating evidence suggests that hypobaric hypoxia negatively impacts skeleton health by diminishing bone quality and disrupting bone microarchitecture. However, therapeutic strategies to counteract this bone loss remain limited. This study investigates the impact of whole-body vibration (WBV) stimulation on skeletal health of rats continuously exposed to simulated hypobaric hypoxia environment at an altitude of 4500 m for 6 weeks. We found that WBV stimulation at 30 Hz and 0.3 g significantly improved femoral bone mass, microarchitecture, and biomechanical properties in rats exposed to chronic hypobaric hypoxia. Additionally, in vitro studies demonstrated that WBV enhanced osteogenic potential and activity in primary osteoblasts under hypoxia conditions. It also reduced levels of hypoxia-inducible factor 1α (HIF-1α), a key transcription factor involved in cellular response to hypoxia. Conversely, overexpression of HIF-1α significantly inhibited cellular differentiation and osteogenesis in osteoblasts exposed to WBV stimulation under hypoxic conditions. Furthermore, WBV stimulation led to a significant increase in nitric oxide (NO) concentrations in osteoblasts during hypoxic exposure. In vitro experiments showed that blocking of NO synthesis with L-NAME impeded WBV-stimulated osteogenic activity in hypoxia-exposed osteoblasts. In vivo studies demonstrated that inhibiting NO synthesis similarly abolished the positive impact of WBV on bone microarchitecture and biomechanical properties under hypobaric hypoxia. Collectivity, our findings indicate that WBV protects against hypobaric hypoxia-induced bone loss by regulating the NO/HIF-1α axis in osteoblasts, and reveal its clinical potential as a promising non-invasive approach.

Quinoa Ethanol Extract Ameliorates Cognitive Impairments Induced by Hypoxia in Mice: Insights into Antioxidant Defense and Gut Microbiome Modulation

Quinoa, rich in pharmacologically active ingredients, possesses the potential benefit in preventing cognitive impairments induced by hypoxia. In this study, the efficacy of quinoa ethanol extracts (QEE) consumption (200 and 500 mg/kg/d, respectively) against hypobaric hypoxia (HH)-induced cognitive deficits in mice was investigated. QEE significantly ameliorated hypoxic stress induced by HH, as evidenced by improvements in baseline indices and reductions in hypoxia-inducible factor 1α levels. Furthermore, QEE enhanced antioxidant defense mechanisms, alleviated neuroinflammation in brain regions associated with memory, and improved HH-induced cognitive impairments by modulating the cyclic adenosine monophosphate response element-binding protein/brain-derived neurotrophic factor signaling pathway. Higher doses generally yielded more effective outcomes than lower doses. QEE also significantly reshaped the gut microbiome structure of HH mice, inhibited gut barrier damage, and reduced lipopolysaccharide migration, thereby increasing short-chain fatty acids (SCFAs) levels. Our findings suggest that QEE may be a promising strategy for preventing hypoxia-induced cognitive impairments by maintaining gut microbiome stability and increasing SCFAs levels.

Engineered Strategies to Interfere with Macrophage Fate in Myocardial Infarction

Myocardial infarction (MI), a severe cardiovascular condition, is typically triggered by coronary artery disease, resulting in ischemic damage and the subsequent necrosis of the myocardium. Macrophages, known for their remarkable plasticity, are capable of exhibiting a range of phenotypes and functions as they react to diverse stimuli within their local microenvironment. In recent years, there has been an increasing number of studies on the regulation of macrophage behavior based on tissue engineering strategies, and its regulatory mechanisms deserve further investigation. This review first summarizes the effects of key regulatory factors of engineered biomaterials (including bioactive molecules, conductivity, and some microenvironmental factors) on macrophage behavior, then explores specific methods for inducing macrophage behavior through tissue engineering materials to promote myocardial repair, and summarizes the role of macrophage-host cell crosstalk in regulating inflammation, vascularization, and tissue remodeling. Finally, we propose some future challenges in regulating macrophage-material interactions and tailoring personalized biomaterials to guide macrophage phenotypes.

Research progress of HIF-1a on immunotherapy outcomes in immune vascular microenvironment

The hypoxia-inducible factor-1α (HIF-1α) plays a key role in facilitating the adaptation of cells to hypoxia, profoundly influencing the immune vascular microenvironment (IVM) and immunotherapy outcomes. HIF-1α-mediated tumor hypoxia drives angiogenesis, immune suppression, and extracellular matrix remodeling, creating an environment that promotes tumor progression and resistance to immunotherapies. HIF-1α regulates critical pathways, including the expression of vascular endothelial growth factor and immune checkpoint upregulation, leading to tumor-infiltrating lymphocyte dysfunction and recruitment of immunosuppressive cells like regulatory T cells and myeloid-derived suppressor cells. These alterations reduce the efficacy of checkpoint inhibitors and other immunotherapies. Recent studies highlight therapeutic strategies that target HIF-1α, such as the use of pharmacological inhibitors, gene editing techniques, and hypoxia-modulating treatments, which show promise in enhancing responses to immunotherapy. This review explores the molecular mechanisms of action of HIF-1α in IVM, its impact on immunotherapy resistance, as well as potential interventions, emphasizing the need for innovative approaches to circumvent hypoxia-driven immunosuppression in cancer therapy.

Functionalized Nanozyme Microcapsules Targeting Deafness Prevention via Mitochondrial Homeostasis Remodeling

Mitochondrial dysfunction, which is the primary mechanism underlying cisplatin-induced hearing loss, can potentially be mitigated by modulating the redox balance and reprogramming the energy metabolism to remodel mitochondrial homeostasis. Herein, N-acetyl-l-cysteine-derived carbonized polymer dots (NAC CPDs) are embedded into manganese porphyrin-doped metal-organic frameworks and encapsulated using a polydopamine (PDA) coating and gelatin methacryloyl (GelMA) hydrogel to afford functionalized nanozyme microcapsules. Owing to their injectability and adhesion properties, these microcapsules exhibit the advantages of prolonged retention in the middle ear and sustained release in the inner ear. The synergy between the manganese porphyrin and polymer dots results in excellent antioxidant properties. The developed nanozymes activate the PI3K-AKT pathway, reprogramming the energy supply mechanism, and inhibiting the oligomerization of BAX in mitochondria to prevent the leakage of mitochondrial DNA and cytochrome c. Therapeutic efficacy and related mechanisms are validated in vivo. Thus, this study on mitochondrial homeostasis remodeling by nanozyme microcapsules opens a new chapter in the treatment of hearing loss.

Hypoxia signaling in the adipose tissue

Obesity per se is rapidly emerging all over the planet and further accounts for many other life-threatening conditions, such as diabetes, cardiovascular diseases, and cancers. Decreased oxygen supply or increased relative oxygen consumption in the adipose tissue results in adipose tissue hypoxia, which is a hallmark of obesity. This review aims to provide an up-to-date overview of the hypoxia signaling in the adipose tissue. First, we summarize literature evidence to demonstrate that hypoxia is regularly observed during adipose tissue remodeling in humans and rodent models with obesity. Next, we discuss how hypoxia-inducible factors (HIFs) are regulated and how adipose tissues behave in response to hypoxia. Then, the differential roles of adipose HIF-1α and HIF-2α in adipose tissue biology and obesity pathology are highlighted. Finally, the review emphasizes the importance of modulating adipose hypoxia as a therapeutic avenue to assist adipose tissues in functionally adapting to hypoxic conditions, ultimately promoting adipose health and improving outcomes due to obesity.

Nanomaterials exert biological effects by influencing the ubiquitin-proteasome system

The ubiquitin-proteasome system (UPS) is an important type of protein post-translational modification that affects the quantity and quality of various proteins and influences cellular processes such as the cell cycle, transcription, oxidative stress, and autophagy. Nanomaterials (NMs), which exhibit excellent physicochemical properties, can directly interact with the UPS and act as molecular-targeted drugs to induce changes in biological processes. This review provides an overview of the influence of NMs on the UPS of misfolded proteins and key proteins, which are related to cancer, neurodegenerative diseases and oxidative stress. This review also summarizes the role of modification processes involved in ubiquitination the biological effects of NMs and the mechanism of such effects of NMs through regulation of the UPS. This review deepens our understanding of the influence of NMs on the protein degradation process and provides new potential therapeutic targets for disease.

Correlation analysis of DLG5 and PD-L1 expression in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is among the most aggressive forms of breast cancer, characterized by a dismal prognosis. In the absence of drug-targetable receptors, chemotherapy remains the sole systemic treatment alternative. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors (ICIs) that target programmed death 1/programmed death ligand 1 (PD-1/PD-L1) and cytotoxic T lymphocyte associated antigen 4 (CTLA-4), have provided renewed optimism for the treatment of patients with TNBC. Prior research has indicated that the expression level of the cell polarity protein discs large homolog 5 (DLG5) correlates with the malignant progression and prognosis of breast cancer; nevertheless, its influence on PD-L1 expression and its function in immunotherapy for TNBC require further investigation.

METHODS

The hypoxia cell model was established by simulating the cell hypoxic microenvironment in the human SUM159 and MDA-MB-231 cell lines using cobalt II chloride (CoCl2). A combination of PD-L1 inhibitors and DLG5 RNA interference techniques was used, along with various methods including cell counting kit-8 (CCK-8), colony formation, wound healing, transwell migration, reverse transcription-quantitative real-time PCR (RT-qPCR), immunofluorescence, immunohistochemical staining (IHC), expression analysis from datasets and western blotting. These methods were employed to evaluate changes in cell proliferation, migration, and the expression levels of PD-L1 and DLG5. Additionally, the correlation between the expression of PD-L1 and DLG5 in clinical samples was analyzed.

RESULTS

(1) In vitro experiments, a cellular hypoxia model was effectively established utilizing 150 µM CoCl₂. Under these conditions, cell clone formation, invasiveness, and migration rate were all significantly inhibited. (2) The expression levels of DLG5 and PD-L1 were significantly increased in both MDA-MB-231 and SUM159 cells following treatment with 150 µM CoCl₂. (3) Silencing DLG5 resulted in a considerable upregulation of PD-L1 expression in MDA-MB-231 and SUM159 cells under normoxic circumstances, but it was markedly downregulated under hypoxic settings. Inhibition of PD-L1 expression resulted in a considerable increase in DLG5 expression under normoxic conditions, but it decreased under hypoxic conditions. Correlation research demonstrated an inverse association between the expression of DLG5 and PD-L1 in TNBC tissues.

CONCLUSION

This study provides new theoretical evidence and potential therapeutic targets for the immunotherapy strategies of TNBC, holding significant clinical application value.

JAK2 inactivating mutations promotes endometrial cancer progression by targeting HIF-1α

OBJECTIVE

Endometrial cancer (EC) is the ninth most common malignancy among women. While mutations in JAK2 are frequently observed in EC, the specific biological functions of JAK2 in endometrial cancer are poorly understood.

METHODS

The genetic alterations of JAK2 in different cancer types were explored using sequencing dataset deposited at TCGA database. JAK2 mutations were detected in EC formalin-fixed paraffin-embedded (FFPE) samples using Sanger sequencing. The expression levels of JAK2 was accessed using the TCGA database and immunohistochemistry. Furthermore, the relationships between JAK2 expression and staging and prognosis of EC patients were investigated using the TCGA database. Down-regulation of JAK2 were achieved by transient transfection with short hairpin RNAs (shRNAs). Effects of JAK2 on cancer cells proliferation and migration were evaluated by CCK8, colony formation, and transwell assay. The potential biological functions of JAK2 in EC were identified based on bioinformatics analysis. Effects of JAK2 on expression levels of target genes were detected by RT-qPCR and western blotting. Co-immunoprecipitation (co-IP) assays was used to detect the physical association between JAK2 and HIF-1α.

RESULTS

Frequent mutations and down-regulation of JAK2 were found in EC. Loss-of-function (LOF) assays suggested that JAK2 silencing in endometrial cancer cells promoted cell proliferation and migration, which were partially dependent on HIF-1α signaling pathway. Furthermore, our findings demonstrated that JAK2 interacted with HIF-1α and reduced HIF1α protein expression under hypoxia.

CONCLUSION

These findings revealed novel molecular mechanisms underlying JAK2 LOF mutations-driven endometrial tumorigenesis and revealed that the HIF-1α pathway may be a potential therapeutic target in JAK2-mutated endometrial cancer.

Ginseng glucosyl oleanolate inhibit cervical cancer cell proliferation and angiogenesis via PI3K/AKT/HIF-1α pathway

Ginseng (Panax ginseng C.A. Meyer) is widely used in several functional foods at present. Ginsenosides, is the most crucial bioactive constituents in ginseng whose antitumor activity have been widely reported. In this study, the effect of ginseng glucosyl oleanolate (GGO) produced from ginsenoside Ro through enzymatic transformation, on cervical cancer was evaluated in vitro and in vivo. GGO significantly inhibited the viability and colony forming ability of HeLa cells, and blocked the cell cycle in G0/G1 phase, which showed its ability to inhibit the proliferation of HeLa cells. GGO exhibited anti-angiogenesis effect in HUVECs, chick chorioallantoic membrane (CAM) and Matrigel plugs model. These effects were related to interference with the paracrine axis of VEGF/VEGFR2 and blockage of the downstream PI3K/AKT/HIF-1α signaling pathway of the autocrine axis. The dual inhibitory effects of GGO were also exhibited in immunocompromised mice undergoing heterograft and suppressed tumor growth without any side effects. These findings provide a theoretical basis for further development of GGO as a functional food with anti-tumor properties.

The Physiological Functions and Therapeutic Potential of Hypoxia-Inducible Factor-1α in Vascular Calcification

HIF-1α plays a crucial regulatory role in vascular calcification (VC), primarily influencing the osteogenic differentiation of VSMCs through oxygen-sensing mechanisms. Under hypoxic conditions, the stability of HIF-1α increases, avoiding PHD and VHL protein-mediated degradation, which promotes its accumulation in cells and then activates gene expressions related to calcification. Additionally, HIF-1α modulates the metabolic state of VSMCs by regulating the pathways that govern the switch between glycolysis and oxidative phosphorylation, thereby further advancing the calcification process. The interaction between HIF-1α and other signaling pathways, such as nuclear factor-κB, Notch, and Wnt/β-catenin, creates a complex regulatory network that serves as a critical driving force in VC. Therefore, a deeper understanding of the role and regulatory mechanism of the HIF-1α signaling during the development and progression of VC is of great significance, as it is not only a key molecular marker for understanding the pathological mechanisms of VC but also represents a promising target for future anti-calcification therapies.

miRNA-199b-5p suppresses of oral squamous cell carcinoma by targeting apical-basolateral polarity via Scribble/Lgl

In epithelial cells, Scribble forms cell-cell junctions and contributes to cell morphology and homeostasis by regulating apical-basolateral polarity in mammals and functions as a tumor suppressor in many carcinomas. The initial diagnosis of oral squamous cell carcinoma is important, and its prognosis is poor when accompanied by metastasis. However, research on the mechanisms of oral squamous cell carcinoma metastasis is insufficient. Herein, we showed that Scribble regulates the apical-basolateral polarity of oral squamous cell carcinoma by regulating lethal giant larvae 1, Scribble module and E-cadherin, the adhesion junction. The expression of lethal giant larvae 1 and E-cadherin decreased when the expression of Scribble was knocked down and their localization was completely disrupted in both the oral squamous cell carcinoma cell line and in vivo model. In particular, the Scribble was involved in oral squamous cell carcinoma metastasis via hsa-miR-199b-5p, which is a microenvironmental factor of hypoxia. The disruption of Scribble localization under hypoxic conditions, but its localization was maintained in miR-199b-5p oral squamous cell carcinoma cell lines and in vivo. These results suggest that Scribble functions as a tumor suppressor marker mediated by miR-199b-5p in oral squamous cell carcinoma.

Targeting the SMURF2-HIF1α axis: a new frontier in cancer therapy

The SMAD-specific E3 ubiquitin protein ligase 2 (SMURF2) has emerged as a critical regulator in cancer biology, modulating the stability of Hypoxia-Inducible Factor 1-alpha (HIF1α) and influencing a network of hypoxia-driven pathways within the tumor microenvironment (TME). SMURF2 targets HIF1α for ubiquitination and subsequent proteasomal degradation, disrupting hypoxic responses that promote cancer cell survival, metabolic reprogramming, angiogenesis, and resistance to therapy. Beyond its role in HIF1α regulation, SMURF2 exerts extensive control over cellular processes central to tumor progression, including chromatin remodeling, DNA damage repair, ferroptosis, and cellular stress responses. Notably, SMURF2's ability to promote ferroptotic cell death through GSTP1 degradation offers an alternative pathway to overcome apoptosis resistance, expanding therapeutic options for refractory cancers. This review delves into the multifaceted interactions between SMURF2 and HIF1α, emphasizing how their interplay impacts metabolic adaptations like the Warburg effect, immune evasion, and therapeutic resistance. We discuss SMURF2's dual functionality as both a tumor suppressor and, in certain contexts, an oncogenic factor, underscoring its potential as a highly versatile therapeutic target. Furthermore, modulating the SMURF2-HIF1α axis presents an innovative approach to destabilize hypoxia-dependent pathways, sensitizing tumors to chemotherapy, radiotherapy, and immune-based treatments. However, the complexity of SMURF2's interactions necessitate a thorough assessment of potential off-target effects and challenges in specificity, which must be addressed to optimize its clinical application. This review concludes by proposing future directions for research into the SMURF2-HIF1α pathway, aiming to refine targeted strategies that exploit this axis and address the adaptive mechanisms of aggressive tumors, ultimately advancing the landscape of precision oncology.

The role of the interplay between macrophage glycolytic reprogramming and NLRP3 inflammasome activation in acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a severe respiratory condition associated with elevated morbidity and mortality. Understanding their complex pathophysiological mechanisms is crucial for developing new preventive and therapeutic strategies. Recent studies highlight the significant role of inflammation involved in ALI/ARDS, particularly the hyperactivation of the NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome in macrophages. This activation drives pulmonary inflammation by releasing inflammatory signalling molecules and is linked to metabolic reprogramming, marked by increased glycolysis and reduced oxidative phosphorylation. However, the relationship between NLRP3 inflammasome activation and macrophage glycolytic reprogramming in ALI/ARDS, as well as the molecular mechanisms regulating these processes, remain elusive. This review provides a detailed description of the interactions and potential mechanisms linking NLRP3 inflammasome activation with macrophage glycolytic reprogramming, proposing that glycolytic reprogramming may represent a promising therapeutic target for mitigating inflammatory responses in ALI/ARDS. KEY POINTS: NLRP3 inflammasome activation is pivotal in mediating the excessive inflammatory response in ALI/ARDS. Glycolytic reprogramming regulates NLRP3 inflammasome activation. Therapeutic potential of targeting glycolytic reprogramming to inhibit NLRP3 inflammasome activation in ALI/ARDS.

ROS: A "booster" for chronic inflammation and tumor metastasis

Reactive oxygen species (ROS) are a group of highly active molecules produced by normal cellular metabolism and play a crucial role in the human body. In recent years, researchers have increasingly discovered that ROS plays a vital role in the progression of chronic inflammation and tumor metastasis. The inflammatory tumor microenvironment established by chronic inflammation can induce ROS production through inflammatory cells. ROS can then directly damage DNA or indirectly activate cellular signaling pathways to promote tumor metastasis and development, including breast cancer, lung cancer, liver cancer, colorectal cancer, and so on. This review aims to elucidate the relationship between ROS, chronic inflammation, and tumor metastasis, explaining how chronic inflammation can induce tumor metastasis and how ROS can contribute to the evolution of chronic inflammation toward tumor metastasis. Interestingly, ROS can have a "double-edged sword" effect, promoting tumor metastasis in some cases and inhibiting it in others. This article also highlights the potential applications of ROS in inhibiting tumor metastasis and enhancing the precision of tumor-targeted therapy. Combining ROS with nanomaterials strategies may be a promising approach to enhance the efficacy of tumor treatment.

Uniaxial static strain enhances osteogenic and angiogenic potential under hypoxic conditions in distraction osteogenesis

OBJECTIVE

Bone incision leads to interrupted and sluggish blood flow in the process of distraction osteogenesis (DO), creating a hypoxia (0-2% oxygen tension) at the center of the bone callus. This hypoxia is critical in the coupling of osteogenesis and angiogenesis during DO. This study aimed to investigate the effect of Uniaxial Static Strain (USS) on osteogenesis in osteoblasts under hypoxic conditions, with a focus on the expression of osteogenic markers and angiogenic factors.

METHODS

The USS was made by a multi-unit tension compression device.Osteoblasts were subjected to 10% USS made under hypoxic conditions to mimic the process of DO in vitro. The cell proliferation, alkaline phosphatase (ALP) activity, mineralized nodule formation, and expression of osteogenic and angiogenic markers were evaluated by using a CCK-8 assay, alkaline phosphatase (ALP) staining, ALP activity assay, alizarin red S staining, qRT-PCR, Western blotting and ELISA.

RESULTS

Hypoxia inhibited osteoblast cell proliferation, ALP activity, mineralized nodule formation, and the expression of runt-related transcription factor 2 (Runx- 2), osteopontin(OPN), osteocalcin (OCN), collagen type I (Col1a1). Conversely, hypoxia upregulated the expression of hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF), which are associated with angiogenesis. However, the application of USS enhanced osteoblasts' osteogenic capacity and upregulated angiogenic factors under hypoxic conditions.

CONCLUSION

USS can enhance osteogenesis in osteoblasts under hypoxic conditions. Moreover, it may stimulate angiogenesis by promoting the expression of VEGF, which further contributes to bone formation. This finding provides important implications for understanding the mechanisms involved in bone regeneration and may have clinical applications in optimizing the effectiveness of DO techniques.

MOGAT3-mediated DAG accumulation drives acquired resistance to anti-BRAF/anti-EGFR therapy in BRAFV600E-mutant metastatic colorectal cancer

BRAFV600E-mutant metastatic colorectal cancer (mCRC) is associated with poor prognosis. The combination of anti-BRAF/anti-EGFR (encorafenib/cetuximab) treatment for patients with BRAFV600E-mutant mCRC improves clinical benefits; unfortunately, inevitable acquired resistance limits the treatment outcome, and the mechanism has not been validated. Here, we discovered that monoacylglycerol O-acyltransferase 3-mediated (MOGAT3-mediated) diacylglycerol (DAG) accumulation contributed to acquired resistance to encorafenib/cetuximab by dissecting a BRAFV600E-mutant mCRC patient-derived xenograft (PDX) model exposed to encorafenib/cetuximab administration. Mechanistically, the upregulated MOGAT3 promoted DAG synthesis and reduced fatty acid oxidation-promoting DAG accumulation and activated PKCα/CRAF/MEK/ERK signaling, driving acquired resistance. Resistance-induced hypoxia promoted MOGAT3 transcriptional elevation; simultaneously, MOGAT3-mediated DAG accumulation increased HIF1A expression at the translation level through PKCα/CRAF/eIF4E activation, strengthening the resistance status. Intriguingly, reducing intratumoral DAG with fenofibrate or PF-06471553 restored the antitumor efficacy of encorafenib/cetuximab in resistant BRAFV600E-mutant mCRC, which interrupted PKCα/CRAF/MEK/ERK signaling. These findings reveal the critical role of the metabolite DAG as a modulator of encorafenib/cetuximab efficacy in BRAFV600E-mutant mCRC, suggesting that fenofibrate might prove beneficial for resistant BRAFV600E-mutant mCRC patients.

How lactate affects immune strategies in lymphoma

Tumor cells undergo metabolic reprogramming through shared pathways, resulting in a hypoxic, acidic, and highly permeable internal tumor microenvironment (TME). Lactate, once only regarded as a waste product of glycolysis, has an inseparable dual role with tumor immunity. It can not only provide a carbon source for immune cells to enhance immunity but also help the immune escape through a variety of ways. Lymphoma also depends on the proliferation signal of TME. This review focuses on the dynamic process of lactate metabolism and immune function changes in lymphoma and aims to comprehensively summarize and explore which genes, transcription factors, and pathways affect the biological changes and functions of immune cells. To deeply understand the complex and multifaceted role of lactate metabolism and immunity in lymphoma, the combination of lactate targeted therapy and classical immunotherapy will be a promising development direction in the future.

Developing new drugs for adult T-cell leukemia/lymphoma by targeting hypoxia: insights from toxicity of MS-275 and its analogs

The low survival rate of adult T-cell leukemia/lymphoma (ATL) underscores the critical need for innovative therapeutic agents. While the pharmacokinetics of HDACis have been documented in several hematological neoplasms, there is a notable gap in research regarding their activity against ATL. Given that hypoxia can induce unpredictable effects on lymphoma cells, this study aimed to evaluate the toxic effects of MS-275 and novel analogs on ATL cells in hypoxic condition for the first time. Protein-protein interaction and gene set enrichment analyses were performed, the expression of HIF1A and downstream targets were assessed, and molecular docking was conducted on MS-275 and novel analogs with HIF-1α. For in vitro studies, at first benzamide analogs of MS-275 were synthesized and then, viability of MT-2 cells was evaluated in hypoxic condition. Enrichment analyses confirmed the involvement of hub genes in HIF-1 signaling pathway and volcano plot revealed over expression of HIF1A, GAL3ST1 and CD274. Molecular docking indicated favorable interaction between MS-275 and analogs with HIF-1α PAS-B domain. Results of alamarBlue assay demonstrated that MS-275 and analogs significantly (p < 0.001) reduced viability of MT-2 cells in hypoxic condition. Findings of the present study hold promise for developing new drugs targeting hypoxia-induced changes in ATL.

Blocking the utilization of carbon sources via two pathways to induce tumor starvation for cancer treatment

Glucose oxidase (GOx) is often used to starvation therapy. However, only consuming glucose cannot completely block the energy metabolism of tumor cells. Lactate can support tumor cell survival in the absence of glucose. Here, we constructed a nanoplatform (Met@HMnO2-GOx/HA) that can deplete glucose while inhibiting the compensatory use of lactate by cells to enhance the effect of tumor starvation therapy. GOx can catalyze glucose into gluconic acid and H2O2, and then HMnO2 catalyzes H2O2 into O2 to compensate for the oxygen consumed by GOx, allowing the reaction to proceed sustainably. Furthermore, metformin (Met) can inhibit the conversion of lactate to pyruvate in a redox-dependent manner and reduce the utilization of lactate by tumor cells. Met@HMnO2-GOx/HA nanoparticles maximize the efficacy of tumor starvation therapy by simultaneously inhibiting cellular utilization of two carbon sources. Therefore, this platform is expected to provide new strategies for tumor treatment.

Nanoreactors with Cascade Catalytic Activity Reprogram the Tumor Microenvironment for Enhanced Immunotherapy by Synchronously Regulating Treg and Macrophage Cells

Immunotherapy has been extensively utilized and studied as a prominent therapeutic strategy for tumors. However, the presence of a hypoxic immunosuppressive tumor microenvironment significantly reduces the efficacy of the treatment, thus impeding its application. In addition, the hypoxic microenvironment can also lead to the enrichment of immunosuppressive cells and reduce the effectiveness of tumor immunotherapy; nanoparticles with biocatalytic activity have the ability to relieve hypoxia in tumor tissues and deliver drugs to target cells and have been widely concerned and applied in the field of tumor therapy. The present study involved the development of a dual nanodelivery system that effectively targets the immune system to modify the tumor microenvironment (TME). The nanodelivery system was developed by incorporating R848 and Imatinib (IMT) into Pt nanozyme loaded hollow polydopamine (P@HP) nanocarriers. Subsequently, their surface was modified with specifically targeted peptides that bind to M2-like macrophages and regulatory T (Treg) cells, thereby facilitating the precise targeting of these cells. When introduced into the tumor model, the nanocarriers were able to selectively target immune cells in tumor tissue, causing M2-type macrophages to change into the M1 phenotype and reducing Treg activation within the tumor microenvironment. In addition, the carriers demonstrated exceptional biocatalytic activity, effectively converting H2O2 into oxygen and water at the tumor site while the drug was active, thereby alleviating the hypoxic inhibitory conditions present in the tumor microenvironment. Additionally, this further enhanced the infiltration of M1-type macrophages and cytotoxic T lymphocytes. Moreover, when used in conjunction with immune checkpoint therapy, the proposed approach demonstrated enhanced antitumor immunotherapeutic effects. The bimodal targeted immunotherapeutic strategy developed in the present study overcomes the drawbacks of traditional immunotherapy approaches while offering novel avenues for the treatment of cancer.

Factors Determining Epithelial-Mesenchymal Transition in Cancer Progression

Epithelial-mesenchymal transition (EMT) is a process in which an epithelial cell undergoes multiple modifications, acquiring both morphological and functional characteristics of a mesenchymal cell. This dynamic process is initiated by various inducing signals that activate numerous signaling pathways, leading to the stimulation of transcription factors. EMT plays a significant role in cancer progression, such as metastasis and tumor heterogeneity, as well as in drug resistance. In this article, we studied molecular mechanisms, epigenetic regulation, and cellular plasticity of EMT, as well as microenvironmental factors influencing this process. We included both in vivo and in vitro models in EMT investigation and clinical implications of EMT, such as the use of EMT in curing oncological patients and targeting its use in therapies. Additionally, this review concludes with future directions and challenges in the wide field of EMT.

Hypoxia-inducible factor-1α can reverse the Adriamycin resistance of breast cancer adjuvant chemotherapy by upregulating transferrin receptor and activating ferroptosis

Breast cancer is a common malignant tumor in women. Ferroptosis, a programmed cell death pathway, is closely associated with breast cancer and its resistance. The transferrin receptor (TFRC) is a key factor in ferroptosis, playing a crucial role in intracellular iron accumulation and the occurrence of ferroptosis. This study investigates the influence and significance of TFRC and its upstream transcription factor hypoxia-inducible factor-1α (HIF1α) on the efficacy of neoadjuvant therapy in breast cancer. The differential gene obtained from clinical samples through genetic sequencing is TFRC. Bioinformatics analysis revealed that TFRC expression in breast cancer was significantly greater in breast cancer tissues than in normal tissues, but significantly downregulated in Adriamycin (ADR)-resistant tissues. Iron-responsive element-binding protein 2 (IREB2) interacts with TFRC and participates in ferroptosis. HIF1α, an upstream transcription factor, positively regulates TFRC. Experimental results indicated higher levels of ferroptosis markers in breast cancer tissue than in normal tissue. In the TAC neoadjuvant regimen-sensitive group, iron ion (Fe2+) and malondialdehyde (MDA) levels were greater than those in the resistant group (all p < .05). Expression levels of TFRC, IREB2, FTH1, and HIF1α were higher in breast cancer tissue compared to normal tissue. Additionally, the expression of the TFRC protein in the TAC neoadjuvant regimen-sensitive group was significantly higher than that in the resistant group (all p < .05), while the difference in the level of expression of IREB2 and FTH1 between the sensitive and resistant groups was not significant (p > .05). The dual-luciferase assay revealed that HIF1α acts as an upstream transcription factor of TFRC (p < .05). Overexpression of HIF1α in ADR-resistant breast cancer cells increased TFRC, Fe2+, and MDA content. After ADR treatment, the cell survival rate decreased significantly, and ferroptosis could be reversed by the combined application of Fer-1 (all p < .05). In conclusion, ferroptosis and chemotherapy resistance are correlated in breast cancer. TFRC is a key regulatory factor influenced by HIF1α and is associated with chemotherapy resistance. Upregulating HIF1α in resistant cells may reverse resistance by activating ferroptosis through TFRC overexpression.

A patent review on hypoxia-inducible factor (HIF) modulators (2021-2023)

INTRODUCTION

Hypoxia-inducible factor (HIF) is a central regulatory factor in detecting and adapting to cellular oxygen stress. Dysregulation of HIF is associated with various human diseases. Seven HIF modulators, including six prolyl hydroxylase (PHD) inhibitors and one HIF-2α inhibitor, have already been approved for the treatment of renal anemia and cancer, respectively.

AREAS COVERED

This review summarizes HIF modulators patented in the 2021-2023 period. This review provides an overview of HIF downregulators, including HIF-1α inhibitors, HIF-2α inhibitors, and HIF-2α degraders, as well as HIF upregulators, including PHD, FIH, and VHL inhibitors, and HIF-2α and HIF-3α agonists.

EXPERT OPINION

Efforts should be made to address the adverse clinical effects associated with approved HIF-modulating drugs, including PHD inhibitors and HIF-2α inhibitors. Identification of the specific buried cavity in the HIF-2α and an opened pocket in HIF-3α offer an avenue for designing novel modulators for HIF-2α or HIF-3α. Given the similarities observed in the binding cavities of HIF-2α and HIF-3α, it should be considered whether the approved HIF-2α inhibitors also inhibit HIF-3α. A comprehensive understanding of the HIF signaling pathway biology would lead to the development of novel small-molecule HIF modulators as innovative therapeutic approaches for a wide range of human diseases.

Hypoxia-Inducible Factor 1α Affects Yak Oocyte Maturation and Early Embryonic Development by Regulating Autophagy

In animal assisted reproductive technology, the production of high-quality oocytes is crucial. The yak, having lived in the Qinghai-Tibet Plateau for an extended period, has reproductive cells that are regulated by hypoxia-inducible factor 1α (HIF-1α). This study aimed to investigate the impact of HIF-1α on yak oocyte maturation and early embryonic development in vitro through the regulation of autophagy. The in vitro maturation process of yak oocytes involved the addition of the HIF-1α inducer DFOM and the inhibitor LW6 to examine their effects on yak oocyte maturation, early embryonic development, cell autophagy, cytochrome P450s (CYP450s) enzyme expression, and cumulus diffusion factors. The findings revealed that DFOM significantly upregulated the expression of HIF-1α, resulting in increased the cumulus diffusion area, elevated first polar body expulsion rate of oocytes, enhanced mitochondrial and actin levels, decreased ROS production, and reduced early apoptosis levels of oocytes. Moreover, DFOM promoted the expression of autophagy-related proteins, CYP450s enzymes, and cumulus diffusion factors, thereby enhancing oocyte maturation and early embryonic development. Conversely, LW6 exhibited opposite effects. The inhibition of autophagy levels with 3-MA during DFOM treatment yielded similar outcomes. Furthermore, reducing autophagy led to increased apoptosis levels at all stages of early embryonic development, as well as a significant decrease in total cell number and ICM/TE ratio of blastocysts. Studies have shown that during the in vitro maturation of yak oocytes, HIF-1α can affect the cumulus expansion area of oocytes by regulating autophagy, the first polar body excretion rate, mitochondrial level, actin level, ROS and early apoptosis level, the CYP450s enzyme, and the expression of cumulus expansion factors, thereby improving the in vitro maturation and early embryonic development of yak oocytes. These findings offer valuable insights into the reproductive regulation mechanism of yaks in hypoxic environments and suggest potential strategies for the advancement of yak assisted reproductive technology.

Roles of HIF-1α signaling in Mycobacterium tuberculosis infection: New targets for anti-TB therapeutics?

Tuberculosis (TB), a deadly infectious disease induced by Mycobacterium tuberculosis (Mtb), continues to be a global public health issue that kill millions of patents every year. Despite significant efforts have been paid to identify effective TB treatments, the emergence of drug-resistant strains of the disease and the presence of comorbidities in TB patients urges us to explore the detailed mechanisms involved in TB immunity and develop more effective innovative anti-TB strategies. HIF-1α, a protein involved in regulating cellular immune responses during TB infection, has been highlighted as a promising target for the development of novel strategies for TB treatment due to its critical roles in anti-TB host immunity. This review provides a summary of current research progress on the roles of HIF-1α in TB infection, highlighting its importance in regulating the host immune response upon Mtb infection and summarizing the influences and mechanisms of HIF-1α on anti-TB immunological responses of host cells. This review also discusses the various challenges associated with developing HIF-1α as a target for anti-TB therapies, including ensuring specificity and avoiding off-target effects on normal cell function, determining the regulation and expression of HIF-1α in TB patients, and developing drugs that can inhibit HIF-1α. More deep understanding of the molecular mechanisms involved in HIF-1α signaling, its impact on TB host status, and systematic animal testing and clinical trials may benefit the optimization of HIF-1α as a novel therapeutic target for TB.

An E3 ligase TRIM1 promotes colorectal cancer progression via K63-linked ubiquitination and activation of HIF1α

Accumulating studies have shown that E3 ligases play crucial roles in regulating cellular biological processes and signaling pathways during carcinogenesis via ubiquitination. Tripartite-motif (TRIM) ubiquitin E3 ligases consist of over 70 members. However, the clinical significance and their contributions to tumorigenesis remain largely unknown. In this study, we analyzed the RNA-sequencing expression of TRIM E3 ligases in colorectal cancer (CRC) and identified 10 differentially expressed genes, among which TRIM1 expression predicted poor prognosis of CRC patients. We demonstrated that TRIM1 expression is positively associated with CRC pathological stages, and higher expression is positively correlated with infiltrating levels of immune cells and immunotherapy biomarkers. TRIM1 expression promotes the proliferation and migration of colorectal cancer cells in vitro and in vivo. Transcriptional analysis showed that TRIM1 is responsible for metabolism promotion and immune suppression. Mechanistically, we found that TRIM1 binds HIF1α and mediates its K63-linked ubiquitination, which is required for HIF1α nuclear translocation and subsequent activation. Ubiquitination occurs at Lys214 in the loop between the two PAS domains of HIF1α, and mutation of Lys214 severely disturbs the function of HIF1α. Besides, HIF1α ubiquitination enhances its binding with proteins involved in cellular trafficking and nucleocytoplasmic transport pathway. Collectively, our results indicate TRIM1's role in predicting prognosis and reveal how TRIM1 functions to upregulate HIF1α expression and promote tumor cell proliferation.