Toward a CRISPR-based mouse model of Vhl-deficient clear cell kidney cancer: Initial experience and lessons learned.

CRISPR is revolutionizing the ability to do somatic gene editing in mice for the purpose of creating new cancer models. Inactivation of the VHL tumor suppressor gene is the signature initiating event in the most common form of kidney cancer, clear cell renal cell carcinoma (ccRCC). Such tumors are usually driven by the excessive HIF2 activity that arises when the VHL gene product, pVHL, is defective. Given the pressing need for a robust immunocompetent mouse model of human ccRCC, we directly injected adenovirus-associated viruses (AAVs) encoding sgRNAs against VHL and other known/suspected ccRCC tumor suppressor genes into the kidneys of C57BL/6 mice under conditions where Cas9 was under the control of one of two different kidney-specific promoters (Cdh16 or Pax8) to induce kidney tumors. An AAV targeting Vhl, Pbrm1, Keap1, and Tsc1 reproducibly caused macroscopic ccRCCs that partially resembled human ccRCC tumors with respect to transcriptome and cell of origin and responded to a ccRCC standard-of-care agent, axitinib. Unfortunately, these tumors, like those produced by earlier genetically engineered mouse ccRCCs, are HIF2 independent.

Double Hit in Clear-Cell Renal Cell Carcinoma With Germline Pathogenic ATM Mutation and Somatic VHL Mutation.

While renal cell carcinoma (RCC) is often linked to smoking, obesity, and hypertension, hereditary forms also account for about 3% of RCC cases. Notably, NCCN guidelines identify 7 major hereditary syndromes associated with an increased RCC risk. Inherited mutations in DNA repair genes, such as ATM, BRCA, and TP53, significantly increase the risk of various cancers. Biallelic pathogenic mutations in ATM cause Ataxia-Telangiectasia (A-T) syndrome, while heterozygous germline pathogenic ATM mutations, present in about 1% of the population, also elevate cancer risk. RCC has not traditionally been associated with germline pathogenic ATM mutations, only limited retrospective analyses have identified such mutations. This case report presents a 68-year-old woman with a germline pathogenic ATM mutation (c.8786+1 G>A) who developed high-risk clear cell RCC followed by an acquired somatic VHL mutation in RCC and a 3-cm serous cystadenoma, illustrating the double-hit phenomenon. Her brother, who shares the same germline pathogenic mutation, was diagnosed with pancreatic cancer and prostate cancer. This case highlights the potential use for enhanced screening protocols for RCC in patients who have germline pathogenic ATM mutations and the importance of research in targeted treatments for tumors driven by dual genetic mechanisms. Increased awareness and vigilant screening for RCC are crucial in managing hereditary cancer syndromes effectively.

Familial and early recurrent pheochromocytoma in a child with a novel in-frame duplication variant of VHL.

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors often linked to underlying genetic variants. Genetic analysis can promote gene-adjusted, specific follow-up, and surveillance protocols for both patients and their families at risk. We report the case of a 7-yr-old boy with bilateral pheochromocytoma, which recurred a year after partial adrenalectomy. The patient's father developed bilateral pheochromocytomas at 25 yr of age. Both individuals possessed a novel heterogeneous in-frame duplication germline variant of VHL, yet neither exhibited other clinical manifestations of von Hippel-Lindau disease (VHL). Traditionally, VHL missense mutations have been associated with a higher risk of PPGL development, whereas truncating mutations typically confer a lower risk. In-frame duplication variants are rarely observed in patients with VHL but may lead to changes in the three-dimensional structure of the translated protein, similar to truncating variants. Our analysis suggests that these in-frame duplications of amino acids in specific regions may cause pheochromocytomas in a manner similar to missense variants. Further accumulation of VHL cases with various genotypes and standardized open-access worldwide databases, including longitudinal and specific clinical data linked to genotypes, is required. It is crucial to consider genetic analyses for pediatricians who may diagnose childhood-onset PPGL.

In Silico Exploration of AHR-HIF Pathway Interplay: Implications for Therapeutic Targeting in ccRCC.

The oxygen-sensing pathway is a crucial regulatory circuit that defines cellular conditions and is extensively exploited in cancer development. Pathogenic mutations in the von Hippel-Lindau (VHL) tumour suppressor impair its role as a master regulator of hypoxia-inducible factors (HIFs), leading to constitutive HIF activation and uncontrolled angiogenesis, increasing the risk of developing clear cell renal cell carcinoma (ccRCC). HIF hyperactivation can sequester HIF-1ß, preventing the aryl hydrocarbon receptor (AHR) from correctly activating gene expression in response to endogenous and exogenous ligands such as TCDD (dioxins). In this study, we used protein-protein interaction networks and gene expression profiling to characterize the impact of VHL loss on AHR activity. Our findings reveal specific expression patterns of AHR interactors following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and in ccRCC. We identified several AHR interactors significantly associated with poor survival rates in ccRCC patients. Notably, the upregulation of the androgen receptor (AR) and retinoblastoma-associated protein (RB1) by TCDD, coupled with their respective downregulation in ccRCC and association with poor survival rates, suggests novel therapeutic targets. The strategic activation of the AHR via selective AHR modulators (SAhRMs) could stimulate its anticancer activity, specifically targeting RB1 and AR to reduce cell cycle progression and metastasis formation in ccRCC. Our study provides comprehensive insights into the complex interplay between the AHR and HIF pathways in ccRCC pathogenesis, offering novel strategies for targeted therapeutic interventions.

Resveratrol liposomes reverse sorafenib resistance in renal cell carcinoma models by modulating PI3K-AKT-mTOR and VHL-HIF signaling pathways.

RCC is a malignant tumor arising from the urothelium of renal parenchyma that remains challenging to be treated. In this study, we assessed the anti-tumor effects of Resveratrol liposomes (RES-lips) combined with sorafenib on renal cell carcinoma (RCC) and explored the potential mechanisms underlying the improvement of sorafenib resistance models. Tumor growth and survival following treatment with sorafenib alone or in combination with RES-lips was evaluated in a RCC xenograft mouse model. Flow cytometry results demonstrated that the combination of RES-lips and sorafenib significantly enhanced the G1/S phase arrest of sorafenib-resistant cells. When compared with the PBS or monotherapy groups, treatment with RES-lips combined with sorafenib exhibited significant inhibition of tumor growth in the RCC xenograft mouse model with tumor growth inhibition (TGI) rates and complete remission (CR) rates of 90.1 % and 50 %, respectively. Concersely, the maximum TGI rate was 53.6 % in the RES-lips monoherapy group and 29.2 % and in the sorafenib monotherapy group, and no animals achieved CR. Additionally, the current combination therapy promoted the proliferation of unactivated splenic lymphocytes and the proliferation of soybean protein A- and lipopolysaccharide-stimulated lymphocytes compared with PBS or monotherapy treatments. Further western blotting analysis suggested that RES-lips may enhance the resistance of RCC to sorafenib by inhibiting PI3K-AKT-mTOR and VHL-HIF signaling pathways, ultimately augmenting the tumor growth inhibition effect of the combination therapy. RES-lips may improve the sorafenib resistance in RCC, and the underlying mechanism may be related to the regulation of PI3K-AKT-mTOR and VHL-HIF signaling pathways.

Phenotypic and Genotypic Features of a Chinese Cohort with Retinal Hemangioblastoma.

Purpose: To delineate the genotype and phenotype of RH in a Chinese cohort. Methods: A group of 51 Chinese probands with RH across 76 eyes was assembled and underwent complete retinal imaging examinations. Sanger sequencing and universal primer quantitative fluorescent multiplex-polymerase chain reaction (UPQFM-PCR) were employed for mutation detection in the coding region of the Von Hippel-Lindal (VHL) gene. For frequency calculation, our series was combined with three large cohorts of East Asian descent through a literature review. Results: The Von Hippel-Lindal (VHL) syndrome was excluded in fifteen patients (median age: 32.00 years) with unilateral solitary RH. Thirty-six patients of younger ages (median: 22.00 years, p = 0.008, Mann-Whitney test) conformed to the diagnostic criteria of the VHL syndrome, and thirty-four patients were genetically confirmed. There were four novel variants identified in the VHL gene. Codons 167, 161 and 86 exhibited a mutation occurrence of more than 5% after pooling with literature data, and the large genomic deletion demonstrated a frequency of 17.65%. The RHs were classified as "extrapapillary", "juxtapapillary" and "mixed" types in 53, 7 and 5 eyes, respectively. Almost all extrapapillary RH lesions were found in the peripheral retina. Hemangioblastomas in the central nervous system (CNS) were observed in 25 out of 31 kindreds (80.65%) with full systemic evaluation data. Conclusions: VHL-associated RH might exhibit earlier onset than non-VHL RH. Large genomic deletions were observed at a notably high frequency in the Chinese series with VHL-associated RH, which might be associated with East Asian ethnicity background. RH could potentially serve as an early indicator of CNS hemangioblastoma.

The significant others of aurora kinase a in cancer: combination is the key.

AURKA is predominantly famous as an essential mitotic kinase. Recent findings have also established its critical role in a plethora of other biological processes including ciliogenesis, mitochondrial dynamics, neuronal outgrowth, DNA replication and cell cycle progression. AURKA overexpression in numerous cancers is strongly associated with poor prognosis and survival. Still no AURKA-targeted drug has been approved yet, partially because of the associated collateral toxicity and partly due to its limited efficacy as a single agent in a wide range of tumors. Mechanistically, AURKA overexpression allows it to phosphorylate numerous pathological substrates promoting highly aggressive oncogenic phenotypes. Our review examines the most recent advances in AURKA regulation and focuses on 33 such direct cancer-specific targets of AURKA and their associated oncogenic signaling cascades. One of the common themes that emerge is that AURKA is often involved in a feedback loop with its substrates, which could be the decisive factor causing its sustained upregulation and hyperactivation in cancer cells, an Achilles heel not exploited before. This dynamic interplay between AURKA and its substrates offers potential opportunities for targeted therapeutic interventions. By targeting these substrates, it may be possible to disrupt this feedback loop to effectively reverse AURKA levels, thereby providing a promising avenue for developing safer AURKA-targeted therapeutics. Additionally, exploring the synergistic effects of AURKA inhibition with its other oncogenic and/or tumor-suppressor targets could provide further opportunities for developing effective combination therapies against AURKA-driven cancers, thereby maximizing its potential as a critical drug target.

VHL synthetic lethality screens uncover CBF-ß as a negative regulator of STING.

Clear cell renal cell carcinoma (ccRCC) represents the most common form of kidney cancer and is typified by biallelic inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene. Here, we undertake genome-wide CRISPR/Cas9 screening to reveal synthetic lethal interactors of VHL, and uncover that loss of Core Binding Factor ß (CBF-ß) causes cell death in VHL-null ccRCC cell lines and impairs tumour establishment and growth in vivo. This synthetic relationship is independent of the elevated activity of hypoxia inducible factors (HIFs) in VHL-null cells, but does involve the RUNX transcription factors that are known binding partners of CBF-ß. Mechanistically, CBF-ß loss leads to upregulation of type I interferon signalling, and we uncover a direct inhibitory role for CBF-ß at the STING locus controlling Interferon Stimulated Gene expression. Targeting CBF-ß in kidney cancer both selectively induces tumour cell lethality and promotes activation of type I interferon signalling.

Genetics, Pathophysiology, and Current Challenges in Von Hippel-Lindau Disease Therapeutics.

This review article focuses on von Hippel-Lindau (VHL) disease, a rare genetic disorder characterized by the development of tumors and cysts throughout the body. It discusses the following aspects of the disease. GENETICS: VHL disease is caused by mutations in the VHL tumor suppressor gene located on chromosome 3. These mutations can be inherited or occur spontaneously. This article details the different types of mutations and their associated clinical features. PATHOPHYSIOLOGY: The underlying cause of VHL disease is the loss of function of the VHL protein (pVHL). This protein normally regulates hypoxia-inducible factors (HIFs), which are involved in cell growth and survival. When pVHL is dysfunctional, HIF levels become elevated, leading to uncontrolled cell growth and tumor formation. CLINICAL MANIFESTATIONS: VHL disease can affect various organs, including the brain, spinal cord, retina, kidneys, pancreas, and adrenal glands. Symptoms depend on the location and size of the tumors. DIAGNOSIS: Diagnosis of VHL disease involves a combination of clinical criteria, imaging studies, and genetic testing. TREATMENT: Treatment options for VHL disease depend on the type and location of the tumors. Surgery is the mainstay of treatment, but other options like radiation therapy may also be used. CHALLENGES: This article highlights the challenges in VHL disease management, including the lack of effective therapies for some tumor types and the need for better methods to monitor disease progression. In conclusion, we emphasize the importance of ongoing research to develop new and improved treatments for VHL disease.

Predicting tumor mutation burden and VHL mutation from renal cancer pathology slides with self-supervised deep learning.

BACKGROUND: Tumor mutation burden (TMB) and VHL mutation play a crucial role in the management of patients with clear cell renal cell carcinoma (ccRCC), such as guiding adjuvant chemotherapy and improving clinical outcomes. However, the time-consuming and expensive high-throughput sequencing methods severely limit their clinical applicability. Predicting intratumoral heterogeneity poses significant challenges in biology and clinical settings. Our aimed to develop a self-supervised attention-based multiple instance learning (SSL-ABMIL) model to predict TMB and VHL mutation status from hematoxylin and eosin-stained histopathological images. METHODS: We obtained whole slide images (WSIs) and somatic mutation data of 350 ccRCC patients from The Cancer Genome Atlas for developing SSL-ABMIL model. In parallel, 163 ccRCC patients from Clinical Proteomic Tumor Analysis Consortium cohort was used as independent external validation set. We systematically compared three different models (Wang-ABMIL, Ciga-ABMIL, and ImageNet-MIL) for their ability to predict TMB and VHL alterations. RESULTS: We first identified two groups of populations with high- and low-TMB (cut-off point = 0.9). In two independent cohorts, the Wang-ABMIL model achieved the highest performance with decent generalization performance (AUROC = 0.83 ± 0.02 and 0.8 ± 0.04 in predicting TMB and VHL, respectively). Attention heatmaps revealed that the Wang-ABMIL model paid the highest attention to tumor regions in high-TMB patients, while in VHL mutation prediction, non-tumor regions were also assigned high attention, particularly the stromal regions infiltrated by lymphocytes. CONCLUSIONS: Our results indicated that SSL-ABMIL can effectively extract histological features for predicting TMB and VHL mutation, demonstrating promising results in linking tumor morphology and molecular biology.

The genetic differences between types 1 and 2 in von Hippel-Lindau syndrome: comprehensive meta-analysis.

BACKGROUND: Patients with von Hippel-Lindau (VHL) disease are at risk of developing tumors in the eye, brain, kidney, adrenal gland, and other organs based on their gene mutations. The VHL tumor suppressor gene contains pathogenic variants responsible for these events. This meta-analysis aims to investigate the genetic differences among the various types of VHL syndrome and their correlation with the location of mutations (exons and domains) in the VHL gene. METHOD: Papers eligible for publication until September 2023 were identified using the electronic databases of PubMed, Google Scholar, Scopus, and EMBASE. The Random Effect model was utilized to evaluate the genetic differences between type 1 and type 2 VHL syndromes. RESULTS: The prevalence of missense mutations (MSs) was found to be 58.9% in type 1, while it was 88.1% in type 2. Interestingly, the probability of observing MSs in type 1 was 0.42 times lower compared to type 2. The mutation hotspots of the VHL gene were R167Q/W, Y98H, R238W, and S65L, respectively. Although type 2 had a high presentation of Y98H and R238W, it did not have a higher S65L than type 1. The analysis demonstrated a statistically significant higher prevalence of truncated mutations (PTMs) in type 1. Among type 1, large/complete deletions (L/C DELs) were found in 16.9% of cases, whereas in type 2 only 3.7%. This difference was statistically significant with a p-value < 0.001. Overall, the probability of identifying mutations in domain 2 compared to domain 1 was found to be 2.13 times higher in type 1 (p-value < 0.001). Furthermore, the probability of detecting exon 1 in comparison with observing exon 2 in type 1 was 2.11 times higher than type 2 and revealed a statistically significant result (p-value < 0.001). The detection of exon 2 was 2.18 times higher in type 1 (p-value < 0.001). In addition, the likelihood of discovering exon 2 compared with others was significantly lower in type 1 compared with type 2 VHL (OR = 0.63, p-value = 0.015). CONCLUSIONS: We have revealed a comprehensive genetic difference between types 1 and 2 of VHL syndrome. The significant differences in MS, PTMs, L/C DELs, and the location of the mutations between type 1 and type 2 VHL patients in the Asian, European, and American populations emphasize the genetic heterogeneity of the syndrome. These findings may pave the way for the diagnosis, treatment, and further investigation of the mechanisms behind this complex genetic disorder.

Surgical Outcomes in Patients with Endolymphatic Sac Tumors: A Single-Center Experience of 29 Patients.

OBJECTIVE: To analyze the clinical features and surgical outcomes of patients with endolymphatic sac tumors (ELSTs). STUDY DESIGN: Single institution retrospective cohort study. METHODS: The clinical data of 29 patients with 30 ELSTs who underwent surgery were retrospectively reviewed. Information on patient demographics, tumor size and grade, intraoperative blood loss volume, hearing and facial nerve outcomes, and follow-up data was collected and analyzed. RESULTS: The main symptoms were hearing loss in 26 ELSTs (86.7%) and tinnitus in 17 (56.7%). Twenty-four (80%) ELSTs were in advanced stages (Grade III). The median tumor volume was 6.35 cm3. The median intraoperative blood loss volume was 300 mL. Facial nerve function was well preserved in 21 patients. Among all patients with Grade III tumors, 12 patients underwent tension-free anterior facial nerve rerouting, and 11 patients (91.7%) maintained good facial nerve function postoperatively (HB I and HB II). Only one patient exhibited permanent vocal cord paralysis, and no patients experienced cerebrospinal fluid (CSF) leakage postoperatively. Gross total resection was achieved in 22 patients (73.3%), 5 patients (16.7%) experienced tumor recurrence, and 3 (10%) had residual tumors. CONCLUSIONS: Most ELSTs tend to be diagnosed in the advanced stage. Tension-free anterior facial nerve rerouting could maximally preserve facial nerve function. The intraoperative blood loss volume was associated with tumor size and stage. Tumor recurrence tends to occur at the posterior edge of the petrosal bone, internal auditory canal, and surface of the posterior fossa. Given the relatively high recurrence rate of ELSTs, long-term follow-up is recommended. LEVEL OF EVIDENCE: 4 Laryngoscope, 2024.

Mandarin fish von Hippel-Lindau protein regulates the NF-κB signaling pathway via interaction with IκB to promote fish ranavirus replication.

The von Hippel-Lindau tumor suppressor protein (VHL), an E3 ubiquitin ligase, functions as a critical regulator of the oxygen-sensing pathway for targeting hypoxia-inducible factors. Recent evidence suggests that mammalian VHL may also be critical to the NF-κB signaling pathway, although the specific molecular mechanisms remain unclear. Herein, the roles of mandarin fish ( Siniperca chuatsi) VHL ( scVHL) in the NF-κB signaling pathway and mandarin fish ranavirus (MRV) replication were explored. The transcription of scVHL was induced by immune stimulation and MRV infection, indicating a potential role in innate immunity. Dual-luciferase reporter gene assays and reverse transcription quantitative PCR (RT-qPCR) results demonstrated that scVHL evoked and positively regulated the NF-κB signaling pathway. Treatment with NF-κB signaling pathway inhibitors indicated that the role of scVHL may be mediated through scIKKα, scIKKß, scIκBα, or scp65. Co-immunoprecipitation (Co-IP) analysis identified scIκBα as a novel target protein of scVHL. Moreover, scVHL targeted scIκBα to catalyze the formation of K63-linked polyubiquitin chains to activate the NF-κB signaling pathway. Following MRV infection, NF-κB signaling remained activated, which, in turn, promoted MRV replication. These findings suggest that scVHL not only positively regulates NF-κB but also significantly enhances MRV replication. This study reveals a novel function of scVHL in NF-κB signaling and viral infection in fish.

Unusual Presentation of Von Hippel-Lindau Syndrome With Gastric Variceal Bleeding.

Gastric varices are most commonly a complication of portal hypertension or splenic vein thrombosis (SVT). The presence of gastric varices due to portal hypertension is significantly less than the prevalence of esophageal varices. SVT is a known complication of pancreatitis due to inflammation or compression of the splenic vein coursing along the posterior surface of the pancreas. Occlusion of the splenic vein leads to left-sided portal hypertension. Left-sided portal hypertension results in the development of collateral vessels that bypass the splenic vein by connecting with the short gastric veins. The associated increased pressure within the gastric vessels results in gastric varices. Gastric varices due to SVT may occur in the absence of or be disproportionate to esophageal varices. We report an interesting case of gastrointestinal bleeding from gastric varices related to cirrhosis secondary to metabolic dysfunction-associated steatohepatitis and SVT secondary to chronic pancreatitis due to pancreatic neuroendocrine tumor (NET) in a patient diagnosed with von Hippel-Lindau (VHL) syndrome.

Optic nerve and chiasm hemangioblastomas in von Hippel-Lindau disease: report of 12 cases and review of the literature.

Introduction: Optic nerve and chiasm hemangioblastomas are rare tumors, occurring sporadically or in the context of von Hippel-Lindau (VHL) disease. They have only been portrayed in isolated case reports and small cohorts. Their natural history and therapeutic strategies are only scarcely described. To better characterize these rare tumors, we retrospectively analyzed an optic nerve and chiasm hemangioblastoma series of 12 VHL patients. By combining our own experience to a review of all known cases in literature, we intended to create treatment recommendations for optic nerve and chiasm hemangioblastomas in VHL patients. Methods: We reviewed two electronic databases in the hospitals of our senior authors, searching for VHL patients with optic nerve or chiasm hemangioblastomas. Clinical data were summarized. Tumor size and growth rate were measured on contrast enhanced MRI. Comparable data were collected by literature review of all available cases in VHL patients (Pubmed, Trip, Google and Google Scholar). Results: Of 269 VHL patients, 12 had optic nerve or chiasm hemangioblastomas. In 10 of 12 patients, tumors were diagnosed upon annual ophthalmoscopic/MRI screening. Of 8 patients who were asymptomatic at diagnosis, 7 showed absent or very slow annual progression, without developing significant vision impairment. One patient developed moderate vision impairment. Two symptomatic patients suffered from rapid tumor growth and progressive vision impairment. Both underwent late-stage surgery, resulting in incomplete resection and progressive vision impairment. One patient presented with acute vision field loss. A watchful-waiting approach was adopted because the hemangioblastoma was ineligible for vision-sparing surgery. One patient developed progressive vision impairment after watchful waiting. In the literature we found 45 patient cases with 48 hemangioblastomas. Discussion: When optic nerve and chiasm hemangioblastomas are diagnosed, we suggest annual MRI follow-up as long as patients do not develop vision impairment. If tumors grow fast, threaten the contralateral eye, or if patients develop progressive vision deficiency; surgical resection must be considered because neurological impairment is irreversible, and resection of large tumors carries a higher risk of further visual decline.

Evaluating the Urinary Exosome microRNA Profile of von Hippel Lindau Syndrome Patients with Clear Cell Renal Cell Carcinoma.

INTRODUCTION: Renal cell carcinoma is one of the ten more common malignant tumors worldwide, with a high incidence and mortality rate. Kidney cancer frequently presents at an advanced stage, and it is almost invariably fatal. Much progress has been made in identifying molecular targets for therapy in the hope of improving survival rates, but still, we have no good markers for early detection or progression of the disease. Von Hippel Lindau syndrome (VHL) is an autosomal dominant cancer hereditary syndrome in which affected individuals are at risk of developing bilateral and multifocal renal cell carcinomas (RCC) as well as other tumors. These patients provide an ideal platform to investigate the potential of urinary exosomal miRNA biomarkers in the early development of ccRCC, as these patients are regularly imaged and tumors are actively monitored until the tumor reaches 3 cm before surgical excision. This allows for pre- and post-surgical urine collection and comparison to excised tumor tissues. Studying different biomarkers in urine can provide comprehensive molecular profiling available to patients and physicians and can be a great source of additional tumor genetic information. METHODS: Pre- and postoperative urine samples were obtained from a cohort of VHL patients undergoing surveillance and surgical excision of ccRCCs, and exosomes were extracted. MicroRNA-Seq analysis was performed on miRNA extracted from both urine-derived exosomes and FFPE material from excised ccRCCs. RESULTS: MicroRNA-Seq analysis highlighted a significant difference in the urinary exosome-derived miRNA expression profiles between VHL patients and normal control individuals. This included decreased expression of the miR-320 family, such as miR-320a, known to be decreased in sporadic ccRCC and suppressed by the HIF1α transcription factor activated by the loss of the VHL gene. MiR-542-5p represented a potential marker of VHL-associated ccRCC that was lowly expressed in normal control urinary exosomes, significantly increased in the preoperative urinary exosomes of tumor-bearing VHL patients, and subsequently reduced to normal levels of expression after tumor excision. In concordance with this, the expression of miR-542-5p was increased in the VHL-associated ccRCC in comparison to the normal kidney. CONCLUSIONS: This study shows the potential for miRNA profiling of exosomes from readily available biofluids to both distinguish VHL patient urine from normal control urine microRNAs and to provide biomarkers for the presence of VHL syndrome-associated ccRCC. Further validation studies are necessary to demonstrate the utility of urinary exosome-derived miRNAs as biomarkers in kidney cancer.

von Hippel-Lindau Syndrome and Secondary Hypertension: A Case Report.

von Hippel-Lindau (VHL) syndrome (OMIM #193300) is an autosomal dominant disorder with incomplete penetrance occurring due to a mutation in the VHL gene present on chromosome 3. We present the case of a 21-year-old male with a history of retinoblastoma presenting with intermittent headaches for one month. He was a known hypertensive and his blood pressure on presentation was 180/100 mmHg. A secondary cause for his hypertension was sought. Multiple cysts in his pancreas, both his kidneys, and a mass in the right suprarenal fossa were detected on an abdominal ultrasonogram and a subsequent computed tomography scan of the abdomen. VHL and a pheochromocytoma were suspected, and a positron emission tomography-computed tomography scan was done which collaborated with the above findings. The presence of multiple cystic lesions in the pancreas and kidneys, especially in an individual with a family history of VHL syndrome, should alert the physician to the possibility of VHL syndrome. The need for evaluation of causes for hypertension, especially in young individuals with resistant hypertension, is also highlighted.

Recent progress in the development of hypoxia-inducible factor 2α (HIF-2α) modulators: Inhibitors, agonists, and degraders (2009-2024).

Hypoxia-inducible factor 2α (HIF-2α) is a critical transcription factor that regulates cellular responses under hypoxic conditions. In situations of insufficient oxygen supply or patients with Von Hippel-Lindau (VHL) mutations, HIF-2α accumulates and forms a heterodimeric complex with aryl hydrocarbon receptor nuclear translocator (ARNT, or HIF-ß). This complex further binds to coactivator p300 and interacts with hypoxia response elements (HREs) on the DNA of downstream target genes, regulating the transcription of a variety of genes (e.g. VEGFA, CCND1, CXCR4, SLC2A1, etc) involved in various processes like angiogenesis, mitochondrial metabolism, cell proliferation, and metastasis. Targeting HIF-2α holds great promise for effectively addressing solid tumors associated with aberrant oxygen-sensing pathways and hypoxia mechanisms, offering broad application prospects. In this review, we provide an overview of recent advancements (2009-2024) in HIF-2α modulators such as inhibitors, agonists, and degraders for cancer therapy. Additionally, we discuss in detail the challenges and future directions regarding HIF-2α modulators.

Single Stage Bilateral Adrenalectomy (Cortical-Sparing) and Pancreatectomy (Corpus-Sparing) in a Patient with Von Hippel-Lindau Disease.

Von Hippel-Lindau (VHL) disease is an autosomal dominant syndrome and affects many organs. We aim to report an adult patient with VHL disease having bilateral adrenal pheochromocytoma and multiple neuroendocrine tumors of the pancreas who was successfully treated with simultaneous function-preserving adrenalectomy and pancreatectomy. A 27-year-old woman was admitted to hospital with hypertension. The computed tomography of the abdomen revealed a solid tumor in both adrenal glands with the sizes of 12x7 cm on the right and 4x4 cm on the left. She also had two pancreatic solid masses in the head and three in the tail with varying sizes. The laboratory tests are all within normal limits except elevated 24-hour urinary metanephrine and normetanephrine. I-123 MIBG scanning showed increased uptake in both adrenal glands. Fine needle aspiration biopsy of the tumor on head of pancreas via endoscopic ultrasonography showed neuroendocrine tumor. Those findings were compatible with bilateral pheochromocytoma and multiple pancreatic neuroendocrine tumors and genetic tests revealed the mutation which confirmed the diagnosis of VHL disease. After suppression with alpha-1 inhibitor, right total, left cortical-sparing adrenalectomy, Whipple procedure for the pancreatic head lesions and spleen-preserving distal pancreatectomy were performed and pancreatic corpus was preserved. This case showed that multiple function-preserving procedures can be safely performed with oncological principles in patients with VHL disease.

Late-Onset Manifestations of Von Hippel-Lindau Syndrome: A Case Report.

Von Hippel-Lindau (VHL) syndrome is characterized by a range of tumors including phaeochromocytomas, pancreatic adenomas, cerebellar haemangioblastomas, and renal cell carcinomas. A 50-year-old male presented with a three-week history of headache. Additionally, the patient exhibited signs of hypertension. Ultrasonography (USG) abdomen and pelvis showed a solid mass lesion in the left adrenal gland, iso-echoic to the renal cortex. On contrast-enhanced computed tomography (CECT) of the brain, a well-defined solid cystic lesion was seen in the left posterior cerebellar hemisphere. Small nodular enhancing lesions were seen in the right cerebellar hemisphere. On further imaging with MRI brain contrast, the lesions in the cerebellum were diagnosed as multifocal hemangioblastomas. Laboratory investigations revealed elevated urinary metanephrines and normetanephrine, suggesting pheochromocytoma. Based on radiological and biochemical investigations, with the features of cerebellar haemangioblastomas and pheochromocytoma, a diagnosis of VHL syndrome was made.