Complete radiological and metabolic response of metastatic renal cell carcinoma to SU5416 (semaxanib) in a patient with probable von Hippel-Lindau syndrome

Construction of the metabolic reprogramming-associated gene signature for clear cell renal cell carcinoma prognosis prediction

BACKGROUND

Metabolism reprogramming is a hallmark that associates tumor growth, metastasis, progressive, and poor prognosis. However, the metabolism-related molecular patterns and mechanism in clear cell renal cell carcinoma (ccRCC) remain unclear. Herein, the purpose of this study was to identify metabolism-related molecular pattern and to investigate the characteristics and prognostic values of the metabolism-related clustering.

METHODS

We comprehensively analyzed the differentially expressed genes (DEGs), and metabolism-related genes (MAGs) in ccRCC based on the TCGA database. Consensus clustering was used to construct a metabolism-related molecular pattern. Then, the biological function, molecular characteristics, Estimate/immune/stomal scores, immune cell infiltration, response to immunotherapy, and chemotherapy were analyzed. We also identified the DEGs between subclusters and constructed a poor signature and risk model based on LASSO regression cox analysis and univariable and multivariable cox regression analyses. Then, a predictive nomogram was constructed and validated by calibration curves.

RESULTS

A total of 1942 DEGs (1004 upregulated and 838 downregulated) between ccRCC tumor and normal samples were identified, and 254 MRGs were screened out from those DEGs. Then, 526 ccRCC patients were divided into two subclusters. The 7 metabolism-related pathways enriched in cluster 2. And cluster 2 with high Estimate/immune/stomal scores and poor survival. While, cluster 1 with higher immune cell infiltrating, expression of the immune checkpoint, IFN, HLA, immune activation-related genes, response to anti-CTLA4 treatment, and chemotherapy. Moreover, we identified 295 DEGs between two metabolism-related subclusters and constructed a 15-gene signature and 9 risk factors. Then, a risk score was calculated and the patients into high- and low-risk groups in TCGA-KIRC and E-MTAB-1980 datasets. And the prediction viability of the risk score was validated by ROC curves. Finally, the clinicopathological characteristics (age and stage), risk score, and molecular clustering, were identified as independent prognostic variables, and were used to construct a nomogram for 1-, 3-, 5-year overall survival predicting. The calibration curves were used to verify the performance of the predicted ability of the nomogram.

CONCLUSION

Our finding identified two metabolism-related molecular subclusters for ccRCC, which facilitates the estimation of response to immunotherapy and chemotherapy, and prognosis after treatment.

The Clinical and Molecular Features in the VHL Renal Cancers; Close or Distant Relatives with Sporadic Clear Cell Renal Cell Carcinoma?

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited cancer syndrome caused by germline mutations in the VHL tumor suppressor gene, characterized by the susceptibility to a wide array of benign and malign neoplasms, including clear-cell renal cell carcinoma. Moreover, VHL somatic inactivation is a crucial molecular event also in sporadic ccRCCs tumorigenesis. While systemic biomarkers in the VHL syndrome do not currently play a role in clinical practice, a new promising class of predictive biomarkers, microRNAs, has been increasingly studied. Lots of pan-genomic studies have deeply investigated the possible biological role of microRNAs in the development and progression of sporadic ccRCC; however, few studies have investigated the miRNA profile in VHL patients. Our review summarize all the new insights related to clinical and molecular features in VHL renal cancers, with a particular focus on the overlap with sporadic ccRCC.

Aryl Hydrocarbon Receptor Mechanisms Affecting Chronic Kidney Disease

The aryl hydrocarbon receptor (AHR) is a basic helix-loop-helix transcription factor that binds diverse endogenous and xenobiotic ligands, which regulate AHR stability, transcriptional activity, and cell signaling. AHR activity is strongly implicated throughout the course of chronic kidney disease (CKD). Many diverse organic molecules bind and activate AHR and these ligands are reported to either promote glomerular and tubular damage or protect against kidney injury. AHR crosstalk with estrogen, peroxisome proliferator-activated receptor-γ, and NF-κB pathways may contribute to the diversity of AHR responses during the various forms and stages of CKD. The roles of AHR in kidney fibrosis, metabolism and the renin angiotensin system are described to offer insight into CKD pathogenesis and therapies.

Ophthalmological Aspects of von-Hippel-Lindau Syndrome

Background: von Hippel-Lindau (VHL) syndrome is a multisystem neoplastic disorder involving eyes, central nervous system, kidneys, spine, and other tissues. A retinal capillary hemangioma (RCH) is the earliest manifestation of the VHL disease in most cases.Areas covered:This paper aims to provide an up-to-date review of the current literature about von Hippel-Lindau syndrome. Molecular background, systemic and ocular features of the diseases as well as the utility of newer imaging modalities in diagnosis and monitoring of ocular VHL disease have been described. Besides, we have discussed newer treatment modalities and therapeutic targets.Conclusion: Modern imaging technologies like optical coherence tomography and optical coherence tomography angiography are tools of the trade, in making an appropriate diagnosis and monitoring disease activity and response to treatment. Peripheral RCH may be treated using laser photocoagulation in tumors up to 3000 µm. Vascular endothelial growth factor suppression can help in reducing tumor activity and stabilize the tumor size; however, it does not regress the RCH.

Structural characterization and pro-angiogenic property of a polysaccharide isolated from red seaweed Bangia fusco-purpurea

In this study, we evaluated the structural characteristics and novel biological activity of polysaccharide purified from red seaweed Bangia fusco-purpurea (BFP). Methylation, GC/MS, and NMR analyses suggested that the proposal repeating structure of BFP was →3)-β-D-Galp-(1→, →3)-β-D-Galp6S-(1 → 4)-α-D-Galp-(1→, →4)-α-D-Galp-(1 → 4)-α-L-AnGalp-(1 → 3)-β-D-Galp-(1→, and →4)-α-D-Galp-(1 → at a molar ratio of 13: 1: 1: 1. Interestingly, BFP exhibited significant cell migration- and tube formation-promoting activities toward human umbilical vein endothelial cells (HUVECs) in a concentration-dependent manner via increasing the N-cadherin expression and decreasing the E-cadherin expression. Furthermore, ERK and p38 mitogen-activated protein kinase (MAPK) specific inhibitors exhibited potent inhibitory effects on BFP-induced cell migration but not JNK MAPK inhibitor, suggesting ERK and p38 MAPK signaling pathways were mainly involved in BFP-induced cell migration. Moreover, vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor significantly inhibited BFP-induced cell migration and tube formation in HUVECs, suggesting VEGF receptors of HUVECs were involved in the pro-angiogenesis activity of BFP. This is the first report that a sulfated polysaccharide possessing a pro-angiogenic effect was obtained from red seaweed. Our findings are expected to promote the practical use of red seaweed B. fusco-purpurea and its polysaccharide in the development of the in vitro and ex vivo vascular endothelial cell-based cell therapy products.

Von Hippel-Lindau Disease: Current Challenges and Future Prospects

Understanding of molecular mechanisms of tumor growth has an increasing impact on the development of diagnostics and targeted therapy of human neoplasia. In this review, we summarize the current knowledge on molecular mechanisms and their clinical implications in von Hippel-Lindau (VHL) disease. This autosomal dominant tumor syndrome usually manifests in young adulthood and predisposes affected patients to the development of benign and malignant tumors of different organ systems mainly including the nervous system and internal organs. A consequent screening and timely preventive treatment of lesions are crucial for patients affected by VHL disease. Surgical indications and treatment have been evaluated and optimized over many years. In the last decade, pharmacological therapies have been evolving, but are largely still at an experimental stage. Effective pharmacological therapy as well as detection of biomarkers is based on the understanding of the molecular basis of disease. The molecular basis of von Hippel-Lindau disease is the loss of function of the VHL protein and subsequent accumulation of hypoxia-inducible factor with downstream effects on cellular metabolism and differentiation. Organs affected by VHL disease may develop frank tumors. More characteristically, however, they reveal multiple separate microscopic foci of neoplastic cell proliferation. The exact mechanisms of tumorigenesis in VHL disease are, however, still not entirely understood and knowledge on biomarkers and targeted therapy is scarce.

Sunitinib for the treatment of benign and malignant neoplasms from von Hippel-Lindau disease: A single-arm, prospective phase II clinical study from the PREDIR group

Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary cancer syndrome that predisposes affected individuals to the development of multiple benign and malignant tumors. One of the main manifestations of VHL is renal cell carcinoma (RCC). RCC is increasingly being treated with targeted therapies, which offer an alternative treatment option for patients with VHL disease. This study investigated the effectiveness of sunitinib in VHL patients with advanced tumors or tumors unsuitable for surgery.This multicenter, phase II, open-label study from the PREDIR VHL network, treated patients with genetically-confirmed advanced VHL disease with oral sunitinib (50 mg/day for 28 days then a 2-week rest period) until progression. Lesions were performed using magnetic resonance imaging (MRI) and computed tomographic (CT) scan. The primary endpoint was objective response rate; secondary endpoints included tolerability and overall survival.All five patients showed stable disease as best response at 6 months. Two patients showed impressive transitory clinical improvement during early cycles. No patient died during sunitinib treatment. Reasons for discontinuing sunitinib therapy were disease progression (n=1), unacceptable toxicity (n=3) and lack of clinical improvement after 7 cycles (10.5 months) with unacceptable toxicity (n=1).In conclusion, sunitinib was of limited benefit in patients with advanced VHL disease, but had better efficacy against metastatic RCC than other VHL-related lesions. Treatment-related toxicity is an important limiting factor in this frail patient population. New agents with different mechanisms of action are required to treat this disease.

Metabolic features of clear-cell renal cell carcinoma: mechanisms and clinical implications

Central to the malignant behaviour that endows cancer cells with growth advantage is their unique metabolism. Cancer cells can process nutrient molecules differently from normal cells and use it to overcome stress imposed on them by various therapies. This metabolic conversion is controlled by specific genetic mutations that are associated with activation of oncogenes and loss of tumour suppressor proteins. Understanding these processes is important as it can lead to the discovery of biomarkers that can predict the aggressiveness of the disease and its response to therapy, and even more importantly, to the development of novel therapeutics. A classic tumour in this respect is clear-cell renal cell carcinoma (RCC). In this review, we will begin with a brief summary of normal cellular bioenergetic pathways, which will be followed by a description of the characteristic metabolism of glucose and lipids in clear-cell RCC cells and its clinical implications. Data relating to the potential effect of dietary nutrients on RCC will also be reviewed along with potential therapies targeted at interrupting specific metabolic pathways in clear-cell RCC.

Functional imaging of renal cell carcinoma

The incidence of early and advanced-stage renal cell carcinoma (RCC) is increasing. Methods of diagnosing, staging and evaluating tumor burden that are more accurate and reliable than the currently available options are needed in order to identify RCC at a stage at which it is curable and to accurately determine the response to treatment. Functional imaging, particularly with combined PET-CT, might improve accuracy of detection and provide essential information that has been unavailable to date. This approach is against a background in which targeted therapies for metastatic RCC have entered clinical practice in the past few years, further highlighting the importance of accurate imaging for patient selection and for monitoring response to treatment. We outline the current clinical status of functional imaging in RCC using PET-CT, which allows simultaneous capture and co-registration of functional and anatomical data. New radiotracers and approaches-including radiolabeled monoclonal antibodies and imaging of tumor hypoxia-are touched on, and areas of future research discussed.

Targeted therapies in renal cell cancer: recent developments in imaging

Targeted therapy has significantly improved the perspectives of patients with metastatic renal cell cancer (mRCC). Frequently, these new molecules cause disease stabilization rather than substantial tumor regression. As treatment options expand with the growing number of targeted agents, there is an increasing need for surrogate markers to early assess tumor response. Here, we review the currently available imaging techniques and response evaluation criteria for the assessment of tumor response in mRCC patients. For computed tomography (CT), different criteria are discussed including the Response Evaluation Criteria in Solid Tumors (RECIST), the Choi criteria, the modified Choi criteria, and the size and attenuation CT (SACT) criteria. Functional imaging modalities are discussed, such as dynamic contrast-enhanced CT (DCE-CT), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), dynamic contrast-enhanced ultrasonography (DCE-US), and positron emission tomography (PET).

Phase I study of SU5416, a small molecule inhibitor of the vascular endothelial growth factor receptor (VEGFR) in refractory pediatric central nervous system tumors

SU5416 is a novel small molecule tyrosine kinase inhibitor of the VEGF receptors 1 and 2. A phase I dose escalation study stratified by concurrent use (stratum II) or absence (stratum I) of enzyme-inducing anticonvulsant drugs was undertaken to estimate the maximum-tolerated dose (MTD) and to describe the toxicity profile of SU5416 in pediatric patients with refractory brain tumors. Dose escalations were conducted independently for stratum I starting at 110 mg/m(2) while stratum II started at 48 mg/m(2). Thirty-three eligible patients were treated on stratum I (n = 23) and stratum II (n = 10). Tumor types included 23 glial tumors, 4 neural tumors, 4 ependymomas, and 2 choroid plexus carcinomas. The MTD in stratum I was initially estimated to be 110 mg/m(2). The protocol was amended to determine the MTD after excluding transient AST elevation. Re-estimation of the MTD began at the 145 mg/m(2) dose level but due to development of SU5416 being stopped by the sponsor, the trial was closed before completion. The most serious drug-related toxicities were grade 3 liver enzyme abnormalities, arthralgia, and hallucinations. The plasma pharmacokinetics of SU5416 was not significantly affected by the concurrent administration of enzyme-inducing anticonvulsant drugs. Mean values of the total body clearance, apparent volume of distribution, and terminal phase half-life of SU5416 for the 19 patients in stratum I were 26.1 +/- 12.5 l/hr/m(2), 41.9 +/- 21.4 l/m(2), and 1.11 +/- 0.41 hr, respectively. The plasma pharmacokinetics of SU5416 in children was similar to previously reported findings in adult cancer patients. Prolonged disease stabilization was observed in 4 of 16 stratum I patients.

Clinical biomarkers of angiogenesis inhibition

INTRODUCTION

An expanding understanding of the importance of angiogenesis in oncology and the development of numerous angiogenesis inhibitors are driving the search for biomarkers of angiogenesis. We review currently available candidate biomarkers and surrogate markers of anti-angiogenic agent effect.

DISCUSSION

A number of invasive, minimally invasive, and non-invasive tools are described with their potential benefits and limitations. Diverse markers can evaluate tumor tissue or biological fluids, or specialized imaging modalities.

CONCLUSIONS

The inclusion of these markers into clinical trials may provide insight into appropriate dosing for desired biological effects, appropriate timing of additional therapy, prediction of individual response to an agent, insight into the interaction of chemotherapy and radiation following exposure to these agents, and perhaps most importantly, a better understanding of the complex nature of angiogenesis in human tumors. While many markers have potential for clinical use, it is not yet clear which marker or combination of markers will prove most useful.

Promise and Progress for Functional and Molecular Imaging of Response to Targeted Therapies

Biomarkers to predict or monitor therapy response are becoming essential components of drug developer's armamentaria. Molecular and functional imaging has particular promise as a biomarker for anticancer therapies because it is non-invasive, can be used longitudinally and provides information on the whole patient or tumor. Despite this promise, molecular or functional imaging endpoints are not routinely incorporated into clinical trial design. As the costs of clinical trials and drug development become prohibitively more expensive, the need for improved biomarkers has become imperative and thus, the relatively high cost of imaging is justified. Imaging endpoints, such as Diffusion-Weighted MRI, DCE-MRI and FDG-PET have the potential to make drug development more efficient at all phases, from discovery screening with in vivo pharmacodynamics in animal models through the phase III enrichment of the patient population for potential responders. This review focuses on the progress of imaging responses to new classes of anti-cancer therapies targeted against PI3 kinase/AKT, HIF-1alpha and VEGF. The ultimate promise of molecular and functional imaging is to theragnostically predict response prior to commencement of targeted therapy.

Genotype-phenotype correlations in von Hippel-Lindau disease

von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome resulting from mutations in the VHL tumor suppressor gene. VHL disease displays marked variation in expression and the presence of pheochromocytoma has been linked to missense VHL mutations. We analyzed genotype-phenotype correlations in 573 individuals with VHL disease. Routine clinical and radiological surveillance of VHL patients and at-risk relatives was associated with increased detection of retinal angiomatosis (73 vs. 59% of cases) and a reduction in age at diagnosis of renal cell carcinoma (RCC) (44.0+/-10.9 vs. 39.7+/-10.3 years). We confirmed the association of pheochromocytoma with missense mutations described previously, but stratifying missense mutations into those that resulted in substitution of a surface amino acid and those that disrupted structural integrity demonstrated that surface amino acid substitutions conferred a higher pheochromocytoma risk. Age at first manifestation of VHL disease was significantly earlier (P=0.001), and age-related risks of retinal angiomas and RCC were higher (P=0.022 and P=0.0008, respectively) in individuals with a nonsense or frameshift mutation than in those with deletions or missense mutations that disrupted the structural integrity of the VHL gene product (pVHL). These results extend genotype-phenotype-protein structure correlations in VHL disease and provide a baseline for future chemoprevention studies in VHL disease.

Anti-angiogenic therapy in the treatment of advanced renal cell cancer

Metastatic renal cell cancer is associated with a poor prognosis and is resistant to traditional chemotherapy agents. The majority of tumours are associated with inactivation of the von Hippel-Lindau gene and subsequent overexpression of proangiogenic factors, including vascular endothelial growth factor (VEGF). Drugs targeting these pathways have undergone clinical testing in renal cell cancer with encouraging results. This type of therapy is set to revolutionise the treatment of renal cell cancer and this review outlines recent evidence from clinical trials investigating the most promising of these agents.

Principles and therapeutic implications of angiogenesis, vasculogenesis and arteriogenesis

The vasculature is the first organ to arise during development. Blood vessels run through virtually every organ in the body (except the avascular cornea and the cartilage), assuring metabolic homeostasis by supplying oxygen and nutrients and removing waste products. Not surprisingly therefore, vessels are critical for organ growth in the embryo and for repair of wounded tissue in the adult. Notably, however, an imbalance in angiogenesis (the growth of blood vessels) contributes to the pathogenesis of numerous malignant, inflammatory, ischaemic, infectious and immune disorders. During the last two decades, an explosive interest in angiogenesis research has generated the necessary insights to develop the first clinically approved anti-angiogenic agents for cancer and blindness. This novel treatment is likely to change the face of medicine in the next decade, as over 500 million people worldwide are estimated to benefit from pro- or anti-angiogenesis treatment. In this following chapter, we discuss general key angiogenic mechanisms in health and disease, and highlight recent developments and perspectives of anti-angiogenic therapeutic strategies.

Signalling platforms that modulate the inflammatory response: new targets for drug development

Therapeutically controlling inflammation is essential for the clinical management of many high-prevalence human diseases. Drugs that block the pro-inflammatory cytokines tumour-necrosis factor-alpha and interleukin-1 (IL-1) can improve outcomes for rheumatoid arthritis and other inflammatory diseases but many patients remain refractory to treatment. Here we explore the need for developing new types of anti-inflammatory drugs and the emergence of novel drug targets based on the clustering of IL-1 receptors into multi-protein aggregates associated with cell adhesions. Interference with receptor aggregation into multi-protein complexes effectively abrogates IL-1 signalling. The exploration of the crucial molecules required for receptor clustering, and therefore signal transduction, offers new targets and scope for anti-inflammatory drug development.

Lessons from phase III clinical trials on anti-VEGF therapy for cancer

In randomized phase III trials two anti-vascular endothelial growth factor (VEGF) approaches have yielded survival benefit in patients with metastatic cancer. In one approach, the addition of bevacizumab, a VEGF-specific antibody, to standard chemotherapy improved overall survival in colorectal and lung cancer patients and progression-free survival in breast cancer patients. In the second approach, multitargeted tyrosine kinase inhibitors that block VEGF receptor and other kinases in both endothelial and cancer cells, demonstrated survival benefit in gastrointestinal stromal tumor and renal-cell-carcinoma patients. By contrast, adding bevacizumab to chemotherapy failed to increase survival in patients with previously treated and refractory metastatic breast cancer. Furthermore, addition of vatalanib, a kinase inhibitor developed as a VEGF receptor-selective agent, to chemotherapy did not show a similar benefit in metastatic colorectal cancer patients. These contrasting responses raise critical questions about how these agents work and how to combine them optimally. We summarize three of the many potential mechanisms of action of anti-VEGF agents, and also discuss progress relating to the identification of potential biomarkers for anti-VEGF-agent efficacy in humans.

A Phase I study of the angiogenesis inhibitor SU5416 (semaxanib) in solid tumours, incorporating dynamic contrast MR pharmacodynamic end points

SU5416 (Z-3-[(2,4-dimethylpyrrol-5-yl)methylidenyl]-2-indolinone; semaxanib) is a small molecule inhibitor of the vascular endothelial growth factor receptor (VEGFR2). A Phase I dose escalation study was performed. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used as a pharmacodynamic assessment tool. In all, 27 patients were recruited. SU5416 was administered twice weekly by fixed rate intravenous infusion. Patients were treated in sequential cohorts of three patients at 48, 65, 85 110 and 145 mg m-2. A further dose level of 190 mg m-2 after a 2-week lead in period at a lower dose was completed; thereafter, the cohort at 145 mg m-2 was expanded. SU5416 showed linear pharmacokinetics to 145 mg m-2 with a large volume of distribution and rapid clearance. A significant degree of interpatient variability was seen. SU5416 was well tolerated, by definition a maximum-tolerated dose was not defined. No reproducible changes were seen in DCE-MRI end points. Serial assessments of VEGF in a cohort of patients treated at 145 mg m-2 did not show a statistically significant treatment-related change. Parallel assessments of the impact of SU5416 on coagulation profiles in six patients showed a transient effect within the fibrinolytic pathway. Clinical experience showed that patients who had breaks of therapy longer than a week could not have treatment reinitiated at a dose of 190 mg m-2 without unacceptable toxicity. The 145 mg m-2 dose level is thus the recommended dose for future study.

Emerging drugs for renal cell carcinoma

Renal cell carcinoma (RCC) still represents a therapeutic challenge when patients have advanced or metastatic disease. Treatment using IL-2 and IFN-alpha continues to be the standard of care in patients who are able to tolerate such regimens. Targeted therapy may become the first-line treatment for patients resistant or intolerant to cytokines as new emerging drugs continue to be investigated. Understanding the genetic abnormalities related to the development of RCC (e.g., VHL gene abnormalities) and identifying molecular targets (e.g., epidermal growth factor, vascular endothelial growth factor and carbonic anhydrase IX) are playing a major role in the emergence of these novel agents for the treatment of this malignancy. Overall, these drugs are better tolerated and more acceptable to use by patients than the traditional cytokine-based regimens. The use of oral drugs to treat various malignancies including RCC seems to be the new paradigm of the future. Further understanding of their mechanisms of action and confirmation of their benefits on the clinical outcome is needed.