Search Results (120)

The leading causes of pediatric arterial ischemic stroke (PAIS) are arteriopathies, which refer to pathologies of the arterial walls in the brain. Since traditional risk factors for cardiovascular diseases in children play a smaller role than in adults, it can be supposed that genetic factors may be of particular importance in this age group. Therefore, this study aimed to identify mutations affecting the formation of vascular wall pathologies, which can subsequently lead to ischemic stroke. The study used a database of 92 Caucasian children diagnosed with ischemic stroke. From this group, 25 children with arteriopathies were selected. The study had an exploratory and descriptive design, with the aim of characterizing rare genetic variants in a selected cohort, without attempting formal statistical association testing. The sequencing was performed using the Illumina NextSeq 550 platform. A panel of 161 genes known to be associated with stroke or arteriopathies was selected for further analysis. We identified 10 pathogenic or likely pathogenic mutations in 15 patients. Among these, three are likely monogenic causes of stroke (ELN, SCN5A, and VHL genes), two are considered risk factors (FV and ADAMTS13), two have conflicting interpretations (ACAD9 and ENG), and three are most likely benign (CBS, PMM2, and PKD1). The frequency of genetic variants underlying ischemic stroke or acting as risk factors for the disease in the studied group is significantly higher than the estimated frequency of monogenic forms of stroke in young adults and higher than in the general population. NGS testing is worth considering, especially in patients who exhibit certain symptoms that may suggest the presence of mutations. Full article

Background/Objectives: An accurate evaluation of variant actionability is essential in cancer management. In Von Hippel–Lindau Syndrome (VHL), the interpretation of the germline variants is confounded by the presence of non-syndromic component tumors, such as clear cell renal cell carcinoma (ccRCC), hemangioblastoma, pheochromocytoma, and neuroendocrine tumors. These tumors frequently occur sporadically, without any association with VHL syndrome. The presence of these tumors in a patient with a germline VHL variant could lead to inaccurate attribution of these tumors to the germline variant and VHL syndrome. In our previous INT²GRATE (INTegrated INTerpretation of GeRmline And Tumor gEnomes) programs, we demonstrated that integrating tumor-derived and germline evidence offers a comprehensive approach for the accurate assessment of the germline variants in cancer syndromes. Methods/Results: Here, we present a novel INT²GRATE variant evidence framework (VEF) for evaluating the clinical actionability of the germline variants in VHL syndrome, offering an integrated approach that incorporates both constitutional and tumor data. We analyzed 2672 variants in the VHL gene and their associated tumors and clinical evidence to effectively distinguish between constitutional, sporadic, VHL differentials, and VHL allelic genetic conditions. The germline INT²GRATE variants, along with their comprehensive associated evidence, were made accessible in the first open-access INT²GRATE Variant data Portal. Conclusions: This novel and integrated approach to variant assessment and data sharing in hereditary cancer syndromes is essential in the clinical evaluation of genomic variants, advancing precision oncology, and improving patient care. Full article

Neurocutaneous syndromes represent a clinically and genetically heterogeneous group of disorders, with tuberous sclerosis complex (TSC), von Hippel–Lindau syndrome (VHL), and ataxia–telangiectasia (A-T) exemplifying some of the most complex entities within this category. These syndromes have traditionally been considered monogenic disorders, caused by germline mutations in tumor suppressor or regulatory genes. However, they exhibit a striking degree of phenotypic variability and divergent clinical trajectories that cannot be fully explained by their underlying genetic alterations alone. Increasingly, epigenetic regulatory mechanisms, such as DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA (ncRNA) activity, are recognized as key modulators of gene expression, cellular differentiation, and tissue-specific function. Disruption of these mechanisms has been implicated in disease pathogenesis, tumorigenesis, and neurodegeneration associated with TSC, VHL, and A-T. Aberrant epigenetic profiles may underlie the observed variability in clinical outcomes, even among individuals with identical mutations. This review consolidates current evidence on the epigenetic landscape of these syndromes, elucidating how these modifications may influence disease behavior and contribute to incomplete genotype–phenotype correlations. By integrating epigenetic insights with known molecular pathways, a more nuanced understanding of disease biology emerges, with potential implications for diagnostic stratification, prognostic assessment, and therapeutic innovation. Full article

The biological significance of sodium–glucose cotransporter 2 (SGLT2) in clear cell renal cell carcinoma (ccRCC) has yet to be elucidated. In this study, we aimed to determine the role of SGLT2 in ccRCC tumor progression. The human ccRCC line KMRC-1, which contains a von Hippel–Lindau (VHL) gene mutation, was used to assess the effects of the SGLT2 inhibitor (SGLT2i) dapagliflozin on proliferation and migration in media containing different glucose concentrations (25, 12.5, or 5 mM). Dapagliflozin significantly reduced cell proliferation and migration in 25 mM glucose medium. Similarly, SGLT2 knockdown involving short hairpin RNA lentiviral transfection significantly decreased cell viability, migration, and colony formation compared with the control subline in 25 mM glucose medium. Moreover, tumor progression was inhibited in the media with low glucose concentrations. Remarkably, 2 µM dapagliflozin inhibited the progression of ccRCC at concentrations as low as 5 mM (normoglycemic model) glucose medium as well as 25 mM (severe glycemia model) glucose medium. In addition, dapagliflozin treatment significantly enhanced the apoptosis of ccRCC cells. Our findings demonstrate that SGLT2 impacts the progression of ccRCC with the VHL mutation. In light of the above findings, SGLT2is, which exert the dual effects of SGLT2 blockade and glycemic control, may represent a novel therapeutic agent, particularly in patients with ccRCC who suffer from concurrent diabetes mellitus. To the best of our knowledge, this is the first preclinical study demonstrating the impact of SGLT2 inhibition on the progression of ccRCC with the VHL mutation. Full article

Transcription factors (TFs) play central roles in gene regulation and disease progression but have long been considered undruggable due to the absence of well-defined binding pockets and their reliance on protein–protein or protein–DNA interactions. Proteolysis-targeting chimeras (PROTACs) offer a novel strategy to overcome these limitations by inducing selective degradation of TFs via the ubiquitin–proteasome system. This review highlights recent advances in TF-targeting PROTACs, focusing on key oncogenic TFs such as androgen receptor (AR), estrogen receptor alpha (ERα), BRD4, c-Myc, and STAT family members. Strategies for ligand design—including small molecules, peptides, and nucleic acid-based elements—are discussed alongside the use of various E3 ligases such as VHL, CRBN, and IAP. Several clinically advanced PROTACs, including ARV-110 and ARV-471, demonstrate the therapeutic potential of this technology. Despite challenges in pharmacokinetics and E3 ligase selection, emerging data suggest that PROTACs can successfully target TFs, paving the way for new treatment strategies across oncology and other disease areas. Full article

Background: Von Hippel-Lindau (VHL) disease, a hereditary cancer syndrome, is characterized by mutations in the VHL gene, which result in the stabilization of hypoxia-inducible factors (HIF)-1α and -2α, ultimately leading to the development of highly vascularized tumors, such as hemangioblastomas of the central nervous system (CNS-HBs). The standard treatment for these brain tumors is neurosurgical resection. However, multiple surgeries are often necessary due to tumor recurrence, which increases the risk of neurological sequelae. Thus, elucidation of the proliferative behavior of hemangioblastomas (with the aim of identifying biomarkers associated with tumor progression) and the development of pharmacological therapies could reduce the need for repeated surgical interventions and provide alternative treatment options for unresectable CNS-HBs. Belzutifan (Welireg™), a selective HIF-2α inhibitor and the only FDA-approved non-surgical option, has shown limited efficacy in CNS-HBs, highlighting the need for alternative therapeutic strategies. Results: In this study, primary cell cultures were successfully established from CNS-HB tissue samples of VHL patients, achieving a 75% success rate. These cultures were predominantly composed of stromal cells and pericytes. The proliferative patterns of patient-derived HB cell cultures significantly correlated with tumor burden and recurrence in VHL patients. Furthermore, flow cytometry, reverse transcription-PCR, and Western blot analyses revealed marked overexpression of both HIF-1α and HIF-2α isoforms in primary HB cells. In addition, evaluation of the therapeutic potential of acriflavine, a dual HIF-1α/HIF-2α inhibitor, demonstrated reduced HB cells viability, induced G2/M cell cycle arrest, and predominantly triggered necrotic cell death in patient-derived HB cultures. Conclusions: These results suggest that the in vitro proliferative dynamics of HB cell cultures may reflect clinical characteristics associated with CNS-HB progression, potentially serving as indicators to predict tumor development in patients with VHL. Furthermore, our findings support the simultaneous targeting of both HIF-1α and HIF-2α isoforms as a promising non-invasive therapeutic strategy. Full article

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. Full article

von Hippel–Lindau syndrome (VHLS) is a hereditary cancer syndrome with CNS hemangioblastomas, clear cell renal carcinoma, pheochromocytoma, retinal angiomas, and a number of other manifestations. VHLS is caused by a mutation in the VHL gene and is inherited in an autosomal dominant manner. However, some cases of VHLS develop de novo, and among them, there are rare patients with a mosaic form of the disease. Genetic testing in mosaic patients is prone to false-negative results due to the low copy number of a mutant allele in DNA isolated from the blood. We describe a case of molecular genetic diagnostics of VHLS in a 39-year-old patient using various methods, including mutation analysis in asynchronous primary tumors and repeated DNA analysis from blood using NGS with high coverage for the mutant position. As a result, the patient was diagnosed with a mosaic form of VHLS caused by the variant c.481C>T (p.Arg161Ter), the proportion of which in the blood DNA was 2%. We also summarized the literature data on the mosaic form of VHLS: the severity of clinical manifestations, the features of differential diagnostics of VHLS with a negative result of routine molecular genetic VHL testing, and specific options of active surveillance and treatment for mutation carriers. Full article

Hypoxic stress causes cell damage and serious diseases in organisms, especially in aquatic animals. It is important to elucidate the changes in metabolic function caused by hypoxia and the mechanisms underlying these changes. This study focuses on the low oxygen tolerance feature of a new blunt snout bream strain (GBSBF1). Our data show that GBSBF1 has a different lipid and carbohydrate metabolism pattern than wild-type bream, with altering glycolysis and lipid synthesis. In GBSBF1, the expression levels of phd2 and vhl genes are significantly decreased, while the activation of HIF-3α protein is observed to have risen significantly. The results indicate that enhanced HIF-3α can positively regulate gpd1ab and gpam through PPAR-γ, which increases glucose metabolism and reduces lipolysis of GBSBF1. This research is beneficial for creating new aquaculture strains with low oxygen tolerance traits. Full article

Background: Pheochromocytoma and paragangliomas (PPGLs) caused refractory hypertension in clinics. The sustained risk of local or metastatic recurrences or new tumor development prompted more research on diagnosis, prognosis prediction, and immunotherapy. Method: The tumor stemness is closely related to the heterogeneous growth of tumor, metastasis, and drug-resistance, and mRNA expression-based stemness indices (mRNAsi) could reflect tumor stemness. This was calculated based on OCLR machine learning algorithm and PPGLs patients’ TCGA RNAseq data. The relationship between clinical, molecular, and tumor microenvironment (TME) features and tumor stemness was analyzed through the hub genes that best captured the stem cell characteristics of PPGLs using weighted gene co-expression network analysis (WGCNA), Cox, and LASSO regression analysis. Results: Our study found that metastatic PPGLs had higher mRNAsi scores, suggesting the degree of tumor stemness could affect metastasis and progression. HRAS, CSDE1, NF1, RET, and VHL-mutant subtypes displayed significant difference in stemness expression. Patients were divided into stemness high-score and low-score subtypes. High-score PPGLs displayed the more unfavorable prognosis compared with low-score, associated with their immune-suppressive features, manifested as low macrophages M1 infiltration and downregulated expression of immune checkpoints. Furthermore, from the viewpoint of stemness features, we established a reliable prognostic for PPGLs, which has the highest AUC value (0.908) in the field so far. And this could stratify PPGLs patients into high-risk and low-risk subtypes, showing the significant differences in prognosis, underlying mechanisms correlated with specific molecular alterations, biological processes activation, and TME. Notably, high immune infiltration and tumor neoantigen in low-risk patients and further resulted in more responsive to immunotherapy. Conclusion: We indicated that tumor stemness could act as the potential biomarker for metastasis or prognosis of PPGLs, and integrated multi-data sources, analyzed valuable stemness-related genes, developed and verified a novel stemness scoring system to predict prognosis and guide the choice of treatment strategies. Full article

Understanding the corpus luteum (CL) and its role in cattle reproduction is crucial, particularly as it is a progesterone source for the establishment and maintenance of pregnancy. Reduced oxygen levels significantly impact these processes. This study investigated the effects of the luteal stage on the spatio-temporal gene expression patterns of HIF1α and oxygen-sensing factors, as well as the impact of lipopolysaccharide (LPS)-induced inflammation on these factors. Endothelial inflammatory responses were also addressed. The samples included CL collected at the early, mid, and late stages, as well as biopsies from mid-luteal stage cows treated either with saline (controls) or LPS. Samples collected in subsequent cycles assessed potential carryover effects. RT-PCR revealed upregulation of HIF1α, PHD1, PHD3, FIH, and VHL encoding genes in the mid-luteal stage. In situ hybridization revealed the compartmentalization of HIF1α and its regulators within the luteal and endothelial cells, suggesting their cell-specific roles. LPS treatment affected PHD1 and PHD3 expression, while increasing endothelial pro-inflammatory factors ICAM1 and NFκB, suggesting vascular inflammation and modulated oxygen sensing. These findings reveal new insights into the spatio-temporal expression of HIF1α-regulating factors in the CL, highlighting their potential role in controlling luteal function, detailing their cellular compartmentalization, and the effects of LPS-mediated inflammatory responses. Full article

Background and Objectives: Von Hippel–Lindau (VHL) disease is caused by mutations in the VHL gene and can develop various cancers. Hypoxia-inducible factors 1 and 2 alphas, regulated by the VHL gene, can increase the levels of vascular endothelial growth factor, thereby activating cancer progression. Here, we demonstrated clinical and prognostic values of VHL expression in rectal cancer (RC). Materials and Methods: Von Hippel–Lindau mRNA expression was examined in 60 patients with RC. Furthermore, we evaluated survival to determine the prognostic significance of VHL mRNA expression levels in RC using the Cancer Genome Atlas (TCGA) data. Results: Lower VHL expression was correlated with the recurrence (p = 0.058) and lymphatic invasion (p = 0.078), although it was not statistically significant. In TCGA data, VHL expression level was correlated with the M stage (p = 0.044); however, it had a possible association with lymphatic invasion (p = 0.068) and N stage (p = 0.104). Survival analysis showed that lower VHL gene expression predicted poorer survival in both patients with RC and TCGA data. Conclusions: This study identified a significant correlation between VHL gene expression and RC for the first time using patient tissues and TCGA data, suggesting that the VHL gene expression level could be a potential biomarker or candidate for the treatment of RC. Further studies are required to identify the molecular pathogenesis and clinical characteristics of VHL disease in RC. Full article

Mutations of the von Hippel–Lindau (VHL) tumor suppressor gene occur frequently in clear cell renal cell carcinoma (RCC), the predominant histology of kidney cancer, and have been associated with its pathogenesis and progression. Alterations of VHL lead to impaired degradation of hypoxia-inducible factor 1α (HIF1α) and HIF2α promoting neoangiogenesis, which is pivotal for cancer growth. As such, targeting the VHL-HIF axis holds relevant potential for therapeutic purposes. Belzutifan, an HIF-2α inhibitor, has been recently indicated for metastatic RCC and other antiangiogenic drugs directed against HIF-2α are currently under investigation. Further, clinical and preclinical studies of combination approaches for metastatic RCC including belzutifan with cyclin-dependent kinase 4–6 inhibitors, tyrosine kinase inhibitors, or immune checkpoint inhibitors achieved promising results or are ongoing. This review aims to summarize the existing evidence regarding the VHL/HIF pathway, and the approved and emerging treatment strategies that target this pivotal molecular axis and their mechanisms of resistance. Full article

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. Full article

Immune checkpoint blockade (ICB), radiotherapy, chemotherapy and surgery are currently used as therapeutic strategies against melanoma, lung, bladder and renal cancers, but their efficacy is limited. Thus, I need to predict treatment response and resistance to address this challenge. In this study, I analyzed 350 lung cancer, 320 melanoma, 215 bladder cancer, 139 head and neck cancer and 151 renal carcinoma patients treated with ICB to identify tumor mutations associated with response and resistance to treatment. I identified several tumor mutations linked with a difference in survival outcomes following ICB. In lung cancer, missense mutations in ABL1, ASXL1, EPHA3, EPHA5, ERBB4, MET, MRE11A, MSH2, NOTCH1, PAK7, PAX5, PGR, ZFHX3, PIK3C3 and REL genes were indicative of favorable responses to ICB. Conversely, mutations in TGFBR2, ARID5B, CDKN2C, HIST1H3I, RICTOR, SMAD2, SMAD4 and TP53 genes were associated with shorter overall survival post-ICB treatment. In melanoma, mutations in FBXW7, CDK12, CREBBP, CTNNB1, NOTCH1 and RB1 genes predict resistance to ICB, whereas missense mutations in FAM46C and RHOA genes are associated with extended overall survival. In bladder cancer, mutations in HRAS genes predict resistance to ICB, whereas missense mutations in ERBB2, GNAS, ATM, CDKN2A and LATS1 genes, as well as nonsense mutations in NCOR1 and TP53 genes, are associated with extended overall survival. In head and neck cancer, mutations in genes like PIK3CA and KRAS correlated with longer survival, while mutations in genes like TERT and TP53 were linked to shorter survival. In renal carcinoma, mutations such as EPHA5, MGA, PIK3R1, PMS1, TSC1 and VHL were linked to prolonged overall survival, while others, including total splice mutations and mutations in B2M, BCOR, JUN, FH, IGF1R and MYCN genes were associated with shorter overall survival following ICB. Then, I developed predictive survival models by machine learning that correctly forecasted cancer patient survival following ICB within an error between 5 and 8 months based on their distinct tumor mutational attributes. In conclusion, this study advocates for personalized immunotherapy approaches in cancer patients. Full article