Targeting β2-Adrenergic Receptors Shows Therapeutical Benefits in Clear Cell Renal Cell Carcinoma from Von Hippel-Lindau Disease

Mutation in Chek2 triggers von Hippel-Lindau hemangioblastoma growth

PURPOSE

Von Hippel-Lindau (VHL) is a rare inherited disease mainly characterized by the growth of tumours, predominantly hemangioblastomas (Hbs) in the CNS and retina, and renal carcinomas. The natural history of VHL disease is variable, differing in the age of onset and its penetrance, even among relatives. Unfortunately, sometimes VHL shows more severe than average: the onset starts in adolescence, and surgeries are required almost every year. In these cases, the factor that triggers the appearance and growth of Hbs usually remains unknown, although additional mutations are suspected.

METHODS

We present the case of a VHL patient whose first surgery was at 13 years of age. Then, along his next 8 years, he has undergone 5 surgeries for resection of 10 CNS Hbs. To clarify this severe VHL condition, DNA from a CNS Hb and white blood cells (WBC) was sequenced using next-generation sequencing technology.

RESULTS

Massive DNA sequencing of the WBC (germ line) revealed a pathogenic mutation in CHEK2 and the complete loss of a VHL allele (both tumour suppressors). Moreover, in the tumour sample, several mutations, in BRAF1 and PTPN11 were found. Familiar segregation studies showed that CHEK2 mutation was in the maternal lineage, while VHL was inherited by paternal lineage.

CONCLUSIONS

Finally, clinical history correlated to the different genotypes in the family, concluding that the severity of these VHL manifestations are due to both, VHL-and-CHEK2 mutations. This case report aims to notice the importance of deeper genetic analyses, in inherited rare diseases, to uncover non-expected mutations.

Trial watch: beta-blockers in cancer therapy

Compelling evidence supports the hypothesis that stress negatively impacts cancer development and prognosis. Irrespective of its physical, biological or psychological source, stress triggers a physiological response that is mediated by the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medullary axis. The resulting release of glucocorticoids and catecholamines into the systemic circulation leads to neuroendocrine and metabolic adaptations that can affect immune homeostasis and immunosurveillance, thus impairing the detection and eradication of malignant cells. Moreover, catecholamines directly act on β-adrenoreceptors present on tumor cells, thereby stimulating survival, proliferation, and migration of nascent neoplasms. Numerous preclinical studies have shown that blocking adrenergic receptors slows tumor growth, suggesting potential clinical benefits of using β-blockers in cancer therapy. Much of these positive effects of β-blockade are mediated by improved immunosurveillance. The present trial watch summarizes current knowledge from preclinical and clinical studies investigating the anticancer effects of β-blockers either as standalone agents or in combination with conventional antineoplastic treatments or immunotherapy.

Propranolol: A “Pick and Roll” Team Player in Benign Tumors and Cancer Therapies

Research on cancer therapies focuses on processes such as angiogenesis, cell signaling, stemness, metastasis, and drug resistance and inflammation, all of which are influenced by the cellular and molecular microenvironment of the tumor. Different strategies, such as antibodies, small chemicals, hormones, cytokines, and, recently, gene editing techniques, have been tested to reduce the malignancy and generate a harmful microenvironment for the tumor. Few therapeutic agents have shown benefits when administered alone, but a few more have demonstrated clear improvement when administered in combination with other therapeutic molecules. In 2008 (and for the first time in the clinic), the therapeutic benefits of the β-adrenergic receptor antagonist, propranolol, were described in benign tumors, such as infantile hemangioma. Propranolol, initially prescribed for high blood pressure, irregular heart rate, essential tremor, and anxiety, has shown, in the last decade, increasing evidence of its antitumoral properties in more than a dozen different types of cancer. Moreover, the use of propranolol in combination therapies with other drugs has shown synergistic antitumor effects. This review highlights the clinical trials in which propranolol is taking part as adjuvant therapy at single administration or in combinatorial human trials, arising as a good pick and roll partner in anticancer strategies.

The Role of Propranolol as a Repurposed Drug in Rare Vascular Diseases

Rare Diseases (RD) are defined by their prevalence in less than 5 in 10,000 of the general population. Considered individually, each RD may seem insignificant, but together they add up to more than 7000 different diseases. Research in RD is not attractive for pharmaceutical companies since it is unlikely to recover development costs for medicines aimed to small numbers of patients. Since most of these diseases are life threatening, this fact underscores the urgent need for treatments. Drug repurposing consists of identifying new uses for approved drugs outside the scope of the original medical indication. It is an alternative option in drug development and represents a viable and risk-managed strategy to develop for RDs. In 2008, the “off label” therapeutic benefits of propranolol were described in the benign tumor Infantile Hemangioma. Propranolol, initially prescribed for high blood pressure, irregular heart rate, essential tremor, and anxiety, has, in the last decade, shown increasing evidence of its antiangiogenic, pro-apoptotic, vasoconstrictor and anti-inflammatory properties in different RDs, including vascular or oncological pathologies. This review highlights the finished and ongoing trials in which propranolol has arisen as a good repurposing drug for improving the health condition in RDs.

ADRB2 is a potential protective gene in breast cancer by regulating tumor immune microenvironment

Background

Breast cancer (BRCA) is the leading cause of cancer death among females. Studies suggested that β-adrenoceptors involved in tumor progression by regulating immune system. However, how ADRB2 affects the immune infiltration in BRCA is still being unraveled.

Methods

Expressions of ADRB2 in multiple tissues, cancers and blood cells were analyzed by using the Human Protein Atlas and UALCAN database. Expression differentiation of ADRB2 in tumor microenvironment (TME) of BRCA was detected in TISCH database. Correlations between ADRB2 and immune cell infiltration were analyzed by TIMER 2.0, and co-expression genes of ADRB2 were obtained from the cBioPortal website. Functional enrichment analyses and protein-protein interactions were constructed as well. Finally, the potential mechanisms of ADRB2 and candidate drugs targeting BRCA were discussed by using the Metascape, STITCH and Cmap tools.

Results

ADRB2 was significantly down-regulated in BRCA, and lower ADRB2 expression often resulted in worse prognosis in BRCA patients. ADRB2 was mainly expressed in breast tissue and blood. Among blood cell subtypes and TME of BRCA, ADRB2 was specifically expressed in T cell subtypes. Also, ADRB2 expression level was positively correlated with the infiltration levels of immune cells such as CD4+ T cell, CD8+ T cell, Tγδ and myeloid DC while negatively correlated with Treg, Tfh and myeloid-derived suppressor cell. Furthermore, functional enrichment analyses revealed that most enriched pathways were immune-related, especially in T cell-related pathways. Also, transcription factors (TFs) analyses showed that most downstream TFs regulated by ADRB2 were immune-related, and most candidate drugs had promising anti-tumor effects.

Conclusions

In conclusion, ADRB2 was a potential protective gene in BRCA, and it might play a vital role in regulating immune responses. The expression level of ADRB2 was positively correlated with immune cells infiltration in BRCA, especially for T cells. Therefore, ADRB2 would be a target for boosting immunotherapy effects in BRCA.

Blockade of β2-Adrenergic Receptor Reduces Inflammation and Oxidative Stress in Clear Cell Renal Cell Carcinoma

Von Hippel-Lindau (VHL) syndrome is a rare inherited cancer disease where the lack of VHL protein triggers the development of multisystemic tumors such us retinal hemangioblastomas (HBs), CNS-HBs, and clear cell renal cell carcinoma (ccRCC). Since standard therapies in VHL have shown limited response, leaving surgery as the only possible treatment, targeting of the β2-adrenergic receptor (ADRB2) has shown therapeutic antitumor benefits on VHL-retinal HBs (clinical trial), VHL-CNS HBs, and VHL-ccRCC (in vitro and in vivo). In the present study, we wanted to look deep into the effects of the ADRB2 blockers propranolol and ICI-118,551 on two main aspects of cancer progression: (i) the changes on the inflammatory response of ccRCC cells; and (ii) the modulation on the Warburg effect (glycolytic metabolism), concretely, on the expression of genes involved in the cell reactive oxygen species (ROS) balance and levels. Accordingly, in vitro studies with primary VHL-ccRCC and 786-O cells measuring ROS levels, ROS-expression of detoxifying enzymes, and the expression of p65/NF-κB targets by RT-PCR were carried out. Furthermore, histological analyses of ccRCC samples from heterotopic mouse xenografts were performed. The obtained results show that ADRB2 blockade in ccRCC cells reduces the level of oxidative stress and stabilizes the inflammatory response. Thus, these data further support the idea of targeting ADRB2 as a promising strategy for the treatment of VHL and other non-VHL tumors.

Von Hippel-Lindau disease-associated renal cell carcinoma: a call to action

PURPOSE OF REVIEW

While the molecular and genetic bases of Von Hippel-Lindau (VHL) disease have been extensively investigated, limited evidence is available to guide diagnosis, local or systemic therapy, and follow-up. The aim of the current review is to summarize the ongoing trials both in preclinical and clinical setting regarding VHL disease management.

RECENT FINDINGS

Although genotype/phenotype correlations have been described, there is considerable inter and intra-familiar heterogeneity in VHL disease. Genetic anticipation has been reported in VHL disease. From a clinical point of view, expert-opinion-based protocols suggest testing those patients with any blood relative of an individual diagnosed with VHL disease, those with at least 1 or more suggestive neoplasms or patients presenting with clear cell renal cell carcinoma (ccRCC) diagnosed at a less than 40 years old, and/or multiple ccRCC. Clinical research is focused on safety and efficacy of systemic agents for patients with VHL-related ccRCC, with the aim to possibly preserve kidney function and improve patient survival.

SUMMARY

To date, preclinical and clinical research on the topic is scarce and clinical guidelines are not supported by strong validation studies.

The Endothelial Landscape and Its Role in Von Hippel-Lindau Disease

Von Hippel–Lindau disease (VHL) is a rare hereditary disease characterized by the predisposal to develop different types of highly vascularized tumors. VHL patients carry a VHL mutation that causes partial lack of functional VHL protein (pVHL) in all cells, and a total lack thereof in cells harboring a second hit mutation. Absence of pVHL generates a prolonged state of pseudo-hypoxia in the cell due to accumulation of hypoxia inducible factor, an important transcription factor regulating pro-tumorigenic genes. The work here presented focuses on characterizing the endothelium of VHL patients, by means of blood outgrowth endothelial cells (BOECs). Transcriptome analysis of VHL-derived BOECs, further supported by in vitro assays, shows that these cells are at a disadvantage, as evidenced by loss of cell adhesion capacity, angiogenesis defects, and immune response and oxidative metabolic gene downregulation, which induce oxidative stress. These results suggest that the endothelium of VHL patients is functionally compromised and more susceptible to tumor development. These findings contribute to shedding light on the vascular landscape of VHL patients preceding the second hit mutation in the VHL gene. This knowledge could be useful in searching for new therapies for these patients and other vascular diseases.

Role of α- and β-adrenergic signaling in phenotypic targeting: significance in benign and malignant urologic disease

The urinary tract is highly innervated by autonomic nerves which are essential in urinary tract development, the production of growth factors, and the control of homeostasis. These neural signals may become dysregulated in several genitourinary (GU) disease states, both benign and malignant. Accordingly, the autonomic nervous system is a therapeutic target for several genitourinary pathologies including cancer, voiding dysfunction, and obstructing nephrolithiasis. Adrenergic receptors (adrenoceptors) are G-Protein coupled-receptors that are distributed throughout the body. The major function of α1-adrenoceptors is signaling smooth muscle contractions through GPCR and intracellular calcium influx. Pharmacologic intervention of α-and β-adrenoceptors is routinely and successfully implemented in the treatment of benign urologic illnesses, through the use of α-adrenoceptor antagonists. Furthermore, cell-based evidence recently established the antitumor effect of α1-adrenoceptor antagonists in prostate, bladder and renal tumors by reducing neovascularity and impairing growth within the tumor microenvironment via regulation of the phenotypic epithelial-mesenchymal transition (EMT). There has been a significant focus on repurposing the routinely used, Food and Drug Administration-approved α1-adrenoceptor antagonists to inhibit GU tumor growth and angiogenesis in patients with advanced prostate, bladder, and renal cancer. In this review we discuss the current evidence on (a) the signaling events of the autonomic nervous system mediated by its cognate α- and β-adrenoceptors in regulating the phenotypic landscape (EMT) of genitourinary organs; and (b) the therapeutic significance of targeting this signaling pathway in benign and malignant urologic disease. Video abstract.

Central Nervous System Hemangioblastoma in a Pediatric Patient Associated With Von Hippel-Lindau Disease: A Case Report and Literature Review

Background

Hemangioblastoma is a benign tumor of the central nervous system and may appear as a component of von Hippel-Lindau (VHL) disease. At present, approximately 40 cases of optic nerve HGBs have been reported in the literature. VHL disease is a rare autosomal-dominant inherited cancer syndrome with different phenotypes caused by variants in the VHL gene. Herein, the authors describe a case of a pediatric patient with VHL disease and with optic nerve HGB, a rare phenotypic expression. The purpose of this study was to explore the genotype-phenotype, clinical features, treatment and follow-up of VHL-associated hemangioblastomas in pediatric patients.

Case Description

A 12-year-old boy presented with vision loss, headache and dizziness at our hospital. Magnetic resonance imaging (MRI) revealed a large (19.8 mm*18.5 mm*23.5 mm) irregular mass located in the suprasellar region. The mass was successfully removed after craniotomy and microsurgical treatment. The pathological diagnosis was left optic nerve HGB. Genetic analyses showed p.Pro86Leu (c. 257C>T) heterozygous missense mutations in the VHL gene.

Conclusion

This is the first reported pediatric case of VHL-associated optic nerve HGB. The genotype-phenotype correlation of VHL disease may provide new evidences for predicting tumor penetrance and survival. Gross tumor resection combined with stereotactic radiosurgery might be the most beneficial treatment.