Interactions between non-coding RNAs and HIF-1α in the context of cancer

Unraveling the role of hypoxia-inducible factors in cutaneous melanoma: from mechanisms to therapeutic opportunities

Hypoxia is a common feature of solid malignancies, including cutaneous melanoma (CM). Hypoxia-inducible factor (HIF)-1α and HIF-2α orchestrate cellular responses to hypoxia and coordinate a transcriptional program that promote several aggressive features in CM, such as angiogenesis, epithelial-mesenchymal transition, metastasis formation, metabolic rewiring, and immune escape. BRAFV600E, which is the most frequent mutation observed in CM patients, usually increases HIF-α signaling not only in hypoxia, but also in normoxic CM cells, enabling HIF-1α and HIF-2α to continuously activate downstream molecular pathways. In this review, we aim to provide a comprehensive overview of the intricate role and regulation of HIF-1α and HIF-2α in CM, with a brief focus on the complex interactions between HIF-α subunits and non-coding RNAs. We also discuss HIF-α-mediated cellular responses in normoxia along with the mechanisms that allow HIF-α subunits to maintain their stability under normal oxygen conditions. Finally, we resume available evidence on potential therapeutic approaches aimed at targeting HIF-1α and/or HIF-2α.

Interactions Between Non-Coding RNAs and HIF-1alpha in the Context of Colorectal Cancer

Hypoxia-inducible factor-1α (HIF-1α), a master regulator of cellular adaptation to hypoxia, drives colorectal cancer (CRC) progression by fueling angiogenesis, metastasis, and therapy resistance. Emerging evidence delineates intricate crosstalk between non-coding RNAs (ncRNAs)-including microRNAs, long non-coding RNAs, and circular RNAs-and HIF-1α, forming bidirectional regulatory networks that orchestrate CRC pathogenesis. By interacting with HIF-1α, these non-coding RNAs contribute to the orchestration of the aggressive hypoxic tumor microenvironment. Recent studies have evaluated the clinical potential of lncRNAs and miRNAs in the realms of non-invasive liquid biopsies and RNA-targeted therapies. This review offers a comprehensive synthesis of recent investigations into the mechanisms by which lncRNAs and miRNAs interact with HIF-1α to modulate CRC progression. Additionally, we further explore the clinical implications of ncRNA/HIF-1α crosstalk, emphasizing their potential as diagnostic biomarkers and therapeutic targets, while also spotlighting intriguing and promising areas of ncRNA research. Methods: In this study, our search strategy employed in databases such as PubMed, Web of Science, and EMBASE is as follows: we will specify search terms, including combinations of "non-coding RNA", "HIF-1α", and "colorectal cancer", along with a date range for the literature search (for example, from 2000 to 2025) to capture the most relevant and up-to-date research.

Tissue nanotransfection-based endothelial PLCγ2-targeted epigenetic gene editing rescues perfusion and diabetic ischemic wound healing

Diabetic wounds are complicated by underlying peripheral vasculopathy. Reliance on vascular endothelial growth factor (VEGF) therapy to improve perfusion makes logical sense, yet clinical study outcomes on rescuing diabetic wound vascularization have yielded disappointing results. Our previous work has identified that low endothelial phospholipase Cγ2 (PLCγ2) expression hinders the therapeutic effect of VEGF on the diabetic ischemic limb. In this work, guided by single-cell RNA sequencing of human wound edge, we test the efficacy of gene-targeted therapeutic demethylation intending to improve VEGF-mediated neovascularization. PLCγ2 expression was diminished in all five identified diabetic wound-edge endothelial subclusters encompassing arterial, venous, and capillary cells. Such low expression was associated with hypermethylated PLCγ2 promoter. PLCγ2 promoter was also hypermethylated at murine diabetic ischemic wound edge. To specifically demethylate endothelial PLCγ2 promoter during VEGF therapy, a CRISPR-dCas9-based demethylation cocktail was delivered to the ischemic wound edge using tissue nanotransfection (TNT) technology. Demethylation-based upregulation of PLCγ2 during VEGF therapy improved wound tissue blood flow with an increased abundance of von Willebrand factor (vWF)+/PLCγ2+ vascular tissue elements by activating p44/p42-mitogen-activated protein kinase (MAPK) → hypoxia-inducible factor [HIF]-1α pathway. Taken together, TNT-based delivery of plasmids to demethylate the PLCγ2 gene promoter activity led to significant improvements in VEGF therapy for cutaneous diabetic wounds, resulting in better perfusion and accelerated wound closure.

Biological roles and molecular mechanism of circular RNAs in epithelial-mesenchymal transition of gastrointestinal malignancies

Circular RNAs (circRNAs) are formed by splicing of precursor RNAs and covalently linked at the 5' and 3' ends. Dysregulated circRNAs are closely related to the epithelial-mesenchymal transition (EMT) of gastrointestinal malignancies. CircRNAs, including circRNA_0008717, circGOT1, circ-DOCK5, circVPS33B, circPVT1, circMET, circ-OXCT1, circ_67835, circRTN4, circ_0087502, circFNDC38, circ_PTEN1, circPGPEP1, and circ-E-Cad are involved in the EMT process of gastrointestinal malignancies through a variety of mechanisms, such as regulating EMT-inducing transcription factors, signaling pathways, and tumor microenvironments. Gastrointestinal (GI) malignancies are common malignant tumors worldwide, and the heterogeneity and easy metastasis of gastrointestinal malignancies limit the effectiveness of medical treatments. Therefore, investigating the molecular mechanisms involved in the pathogenesis of gastrointestinal malignancies is essential for clinical treatment. This article summarizes the biological roles and molecular mechanism of circRNAs in EMT of gastrointestinal malignancies, providing a theoretical basis for applying EMT-related circRNAs in targeted therapy.

Mitochondrial DNA transcription and mitochondrial genome-encoded long noncoding RNA in diabetic retinopathy

In diabetic retinopathy, mitochondrial DNA (mtDNA) is damaged and mtDNA-encoded genes and long noncoding RNA cytochrome B (LncCytB) are downregulated. LncRNAs lack an open reading frame, but they can regulate gene expression by associating with DNA/RNA/protein. Double stranded mtDNA has promoters on both heavy (HSP) and light (LSP) strands with binding sites for mitochondrial transcription factor A (TFAM) between them. The aim was to investigate the role of LncCytB in mtDNA transcription in diabetic retinopathy. Using human retinal endothelial cells incubated in high glucose, the effect of regulation of LncCytB on TFAM binding at mtDNA promoters was investigated by Chromatin immunoprecipitation, and binding of LncCytB at TFAM by RNA immunoprecipitation and RNA fluorescence in situ hybridization. High glucose decreased TFAM binding at both HSP and LSP, and binding of LncCytB at TFAM. While LncCytB overexpression ameliorated decrease in TFAM binding and transcription of genes encoded by both H- and L- strands, LncCytB-siRNA further downregulated them. Maintenance of mitochondrial homeostasis by overexpressing mitochondrial superoxide dismutase or Sirtuin-1 protected diabetes-induced decrease in TFAM binding at mtDNA and LncCytB binding at TFAM, and mtDNA transcription. Similar results were obtained from mouse retinal microvessels from streptozotocin-induced diabetic mice. Thus, LncCytB facilitates recruitment of TFAM at HSP and LSP, and its downregulation in diabetes compromises the binding, resulting in the downregulation of polypeptides encoded by mtDNA. Regulation of LncCytB, in addition to protecting mitochondrial genomic stability, should also help in maintaining the transcription of mtDNA encoded genes and electron transport chain integrity in diabetic retinopathy.

LINC00518: a key player in tumor progression and clinical outcomes

Long non-coding RNAs (lncRNAs), defined as RNA molecules exceeding 200 nucleotides in length, have been implicated in the regulation of various biological processes and the progression of tumors. Among them, LINC00518, a recently identified lncRNA encoded by a gene located on chromosome 6p24.3, consists of three exons and is predicted to positively regulate the expression of specific genes. LINC00518 has emerged as a key oncogenic lncRNA in multiple cancer types. It exerts its tumor-promoting effects by modulating the expression of several target genes, primarily through acting as a sponge for microRNAs (miRNAs). Additionally, LINC00518 influences critical signaling pathways, including the Wnt/β-catenin, JAK/STAT, and integrin β3/FAK pathways. Elevated levels of LINC00518 in tumor tissues are associated with increased tumor size, advanced clinical stage, metastasis, and poor survival prognosis. This review provides a comprehensive summary of the genetic characteristics, expression patterns, biological functions, and underlying mechanisms of LINC00518 in human diseases.

Targeting Hypoxia-Inducible Factor-1 (HIF-1) in Cancer: Emerging Therapeutic Strategies and Pathway Regulation

Hypoxia-inducible factor-1 (HIF-1) is a key regulator for balancing oxygen in the cells. It is a transcription factor that regulates the expression of target genes involved in oxygen homeostasis in response to hypoxia. Recently, research has demonstrated the multiple roles of HIF-1 in the pathophysiology of various diseases, including cancer. It is a crucial mediator of the hypoxic response and regulator of oxygen metabolism, thus contributing to tumor development and progression. Studies showed that the expression of the HIF-1α subunit is significantly upregulated in cancer cells and promotes tumor survival by multiple mechanisms. In addition, HIF-1 has potential contributing roles in cancer progression, including cell division, survival, proliferation, angiogenesis, and metastasis. Moreover, HIF-1 has a role in regulating cellular metabolic pathways, particularly the anaerobic metabolism of glucose. Given its significant and potential roles in cancer development and progression, it has been an intriguing therapeutic target for cancer research. Several compounds targeting HIF-1-associated processes are now being used to treat different types of cancer. This review outlines emerging therapeutic strategies that target HIF-1 as well as the relevance and regulation of the HIF-1 pathways in cancer. Moreover, it addresses the employment of nanotechnology in developing these promising strategies.

Molecular mechanism of oroxyli semen against triple-negative breast cancer verified by bioinformatics and in vitro experiments

OBJECTIVE

This study aimed to use network pharmacology to predict the therapeutic mechanism of oroxyli semen (OS) on triple-negative breast cancer (TNBC) and validate it through in vitro experiments.

METHODS

The active ingredients and target proteins of OS were retrieved from the Traditional Chinese Medicine Systems Pharmacology database, and the TNBC-related target genes were obtained from the GeneCards database. The overlapping genes were used to construct a protein-protein interaction (PPI) network via the String database. Furthermore, we employed an online bioinformatics analysis platform (https://www.bioinformatics.com.cn/) to perform gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses to evaluate biological processes, molecular functions, and cellular components and generate simulated signal pathways. Additionally, molecular docking was used to evaluate the binding ability of small molecule drugs and signaling pathway targets. CCK8 assay was conducted to detect the effect of small molecule drugs on TNBC cell viability, and Western Blot was utilized to verify the expression of AKT, VEGF, and hypoxia-inducible factor 1-alpha (HIF-1α) proteins.

RESULTS

Fifteen active ingredients and 166 therapeutic targets of OS were obtained from the Traditional Chinese Medicine Systems Pharmacology database. The Venn diagram revealed that 163 targets were related to TNBC. The protein-protein interaction network analysis identified AKT1, IL-6, JUN, vascular endothelial growth factor A (VEGFA), CASP3, and HIF-1α as potential core targets through which OS may treat TNBC. Furthermore, the molecular docking results indicated that the active ingredient chryseriol in OS had good binding ability with VEGFA, and HIF-1α. CCK8 assay results indicated that chryseriol inhibited the viability of MDA-MB-231 and BT-20 cells. Western Blot demonstrated that chryseriol intervention led to a decrease in VEGFA, and HIF-1α protein expression compared with the control group (P < .05), increased the cleaved PARP.

CONCLUSION

OS may exert its therapeutic effects on TNBC through multiple cellular signaling pathways. Chryseriol, the active component of OS, can enhance the apoptosis of TNBC cells by targeting VEGFA/HIF-1α pathway. This study provided new insights into the potential therapeutic mechanism of OS for TNBC and may aid in the development of novel therapeutic approaches for TNBC.