Using urinary bFGF and TIMP3 levels to predict the presence of juvenile pilocytic astrocytoma and establish a distinct biomarker signature

Discovery and Characterization of Ephrin B2 and EphB4 Dysregulation and Novel Mutations in Cerebral Cavernous Malformations: In Vitro and Patient-Derived Evidence of Ephrin-Mediated Endothelial Cell Pathophysiology

Intracranial vascular malformations manifest on a continuum ranging from predominantly arterial to predominantly venous in pathology. Cerebral cavernous malformations (CCMs) are capillary malformations that exist at the midpoint of this continuum. The axon guidance factor Ephrin B2 and its receptor EphB4 are critical regulators of vasculogenesis in the developing central nervous system. Ephrin B2/EphB4 dysregulation has been implicated in the pathogenesis of arterial-derived arteriovenous malformations and vein-based vein of Galen malformations. Increasing evidence supports the hypothesis that aberrant Ephrin B2/EphB4 signaling may contribute to developing vascular malformations, but their role in CCMs remains largely uncharacterized. Evidence of Ephrin dysregulation in CCMs would be important to establish a common link in the pathogenic spectrum of EphrinB2/Ephb4 dysregulation. By studying patient-derived primary CCM endothelial cells (CCMECs), we established that CCMECs are functionally distinct from healthy endothelial cell controls; CCMECs demonstrated altered patterns of migration, motility, and impaired tube formation. In addition to the altered phenotype, the CCMECs also displayed an increased ratio of EphrinB2/EphB4 compared to the healthy endothelial control cells. Furthermore, whole exome sequencing identified mutations in both EphrinB2 and EphB4 in the CCMECs. These findings identify functional alterations in the EphrinB2/EphB4 ratio as a feature linking pathophysiology across the spectrum of arterial, capillary, and venous structural malformations in the central nervous system while revealing a putative therapeutic target.

Disease specific urinary biomarkers in the central nervous system

Urinary biomarkers can diagnose and monitor pathophysiologic conditions in the central nervous system (CNS). However, focus is often on single diseases, with limited data on discriminatory capability of this approach in a general setting. Here, we demonstrate that different classes of CNS disease exhibit distinct biomarker patterns, evidence of disease-specific "fingerprinting." Urine from 218 patients with pathology-confirmed tumors or cerebrovascular disease, controls (n = 33) were collected. ELISA and/or bead-based multiplexing quantified levels of 21 putative urinary biomarkers. Analysis identified biomarkers capable of distinguishing each disease from controls and other diseases. Mann-Whitney U tests identified biomarkers with differential expression between disease types and controls (P ≤ 0.001). Subsequent receiver-operating characteristic (ROC) analyses revealed distinguishing biomarkers with high sensitivity and specificity. Areas under the curve (AUCs) ranged 0.8563-1.000 (P values ≤ 0.0003), sensitivities ranged 80.00-100.00%, and specificities ranged 80.95-100.00%. These data demonstrate proof-of-principle evidence that disease-specific urinary biomarker signatures exist. In contrast to non-specific responses to ischemia or injury, these results suggest that urinary biomarkers accurately reflect unique biological processes distinct to different diseases. This work can be used to generate disease-specific panels for enhancing diagnosis, assisting less-invasive follow-up and herald utility by revealing putative disease-specific therapeutic targets.

Factors Influencing Collateral Circulation Formation After Indirect Revascularization for Moyamoya Disease: a Narrative Review

Indirect revascularization is one of the main techniques for the treatment of Moyamoya disease. The formation of good collateral circulation is a key measure to improve cerebral blood perfusion and reduce the risk of secondary stroke, and is the main method for evaluating the effect of indirect revascularization. Therefore, how to predict and promote the formation of collateral circulation before and after surgery is important for improving the success rate of indirect revascularization in Moyamoya disease. Previous studies have shown that vascular endothelial growth factor, endothelial progenitor cells, Caveolin-1, and other factors observed in patients with Moyamoya disease may play a key role in the generation of collateral vessels after indirect revascularization through endothelial hyperplasia and smooth muscle migration. In addition, mutations in the genetic factor RNF213 have also been associated with this process. This study summarizes the factors and mechanisms influencing collateral circulation formation after indirect revascularization in Moyamoya disease.

Physiological and pathophysiological mechanisms of the molecular and cellular biology of angiogenesis and inflammation in moyamoya angiopathy and related vascular diseases

Rationale

The etiology and pathophysiological mechanisms of moyamoya angiopathy (MMA) remain largely unknown. MMA is a progressive, occlusive cerebrovascular disorder characterized by recurrent ischemic and hemorrhagic strokes; with compensatory formation of an abnormal network of perforating blood vessels that creates a collateral circulation; and by aberrant angiogenesis at the base of the brain. Imbalance of angiogenic and vasculogenic mechanisms has been proposed as a potential cause of MMA. Moyamoya vessels suggest that aberrant angiogenic, arteriogenic, and vasculogenic processes may be involved in the pathophysiology of MMA. Circulating endothelial progenitor cells have been hypothesized to contribute to vascular remodeling in MMA. MMA is associated with increased expression of angiogenic factors and proinflammatory molecules. Systemic inflammation may be related to MMA pathogenesis.

Objective

This literature review describes the molecular mechanisms associated with cerebrovascular dysfunction, aberrant angiogenesis, and inflammation in MMA and related cerebrovascular diseases along with treatment strategies and future research perspectives.

Methods and results

References were identified through a systematic computerized search of the medical literature from January 1, 1983, through July 29, 2022, using the PubMed, EMBASE, BIOSIS Previews, CNKI, ISI web of science, and Medline databases and various combinations of the keywords "moyamoya," "angiogenesis," "anastomotic network," "molecular mechanism," "physiology," "pathophysiology," "pathogenesis," "biomarker," "genetics," "signaling pathway," "blood-brain barrier," "endothelial progenitor cells," "endothelial function," "inflammation," "intracranial hemorrhage," and "stroke." Relevant articles and supplemental basic science articles almost exclusively published in English were included. Review of the reference lists of relevant publications for additional sources resulted in 350 publications which met the study inclusion criteria. Detection of growth factors, chemokines, and cytokines in MMA patients suggests the hypothesis of aberrant angiogenesis being involved in MMA pathogenesis. It remains to be ascertained whether these findings are consequences of MMA or are etiological factors of MMA.

Conclusions

MMA is a heterogeneous disorder, comprising various genotypes and phenotypes, with a complex pathophysiology. Additional research may advance our understanding of the pathophysiology involved in aberrant angiogenesis, arterial stenosis, and the formation of moyamoya collaterals and anastomotic networks. Future research will benefit from researching molecular pathophysiologic mechanisms and the correlation of clinical and basic research results.

A novel technology for home monitoring of lupus nephritis that tracks the pathogenic urine biomarker ALCAM

Introduction

The gold standard for diagnosis of active lupus nephritis (ALN), a kidney biopsy, is invasive with attendant morbidity and cannot be serially repeated. Urinary ALCAM (uALCAM) has shown high diagnostic accuracy for renal pathology activity in ALN patients.

Methods

Lateral flow assays (LFA) for assaying uALCAM were engineered using persistent luminescent nanoparticles, read by a smartphone. The stability and reproducibility of the assembled LFA strips and freeze-dried conjugated nanoparticles were verified, as was analyte specificity.

Results

The LFA tests for both un-normalized uALCAM (AUC=0.93) and urine normalizer (HVEM)-normalized uALCAM (AUC=0.91) exhibited excellent accuracies in distinguishing ALN from healthy controls. The accuracies for distinguishing ALN from all other lupus patients were 0.86 and 0.74, respectively.

Conclusion

Periodic monitoring of uALCAM using this easy-to-use LFA test by the patient at home could potentially accelerate early detection of renal involvement or disease flares in lupus patients, and hence reduce morbidity and mortality.

Pediatric Moyamoya Biomarkers: Narrowing the Knowledge Gap

Moyamoya is a progressive cerebrovascular disorder that leads to stenosis of the arteries in the distal internal carotid, proximal middle cerebral and proximal anterior cerebral arteries of the circle of Willis. Typically a network of collaterals form to bypass the stenosis and maintain cerebral blood flow. As moyamoya progresses it affects the anterior circulation more commonly than posterior circulation, and cerebral blood flow becomes increasingly reliant on external carotid supply. Children with moyamoya are at increased risk for ischemic symptoms including stroke and transient ischemic attacks (TIA). In addition, cognitive decline may occur over time, even in the absence of clinical stroke. Standard of care for stroke prevention in children with symptomatic moyamoya is revascularization surgery. Treatment of children with asymptomatic moyamoya with revascularization surgery however remains more controversial. Therefore, biomarkers are needed to assist with not only diagnosis but also with determining ischemic risk and identifying best surgical candidates. In this review we will discuss the current knowledge as well as gaps in research in relation to pediatric moyamoya biomarkers including neurologic presentation, cognitive, neuroimaging, genetic and biologic biomarkers of disease severity and ischemic risk.

A phase I/II study of veliparib (ABT-888) with radiation and temozolomide in newly diagnosed diffuse pontine glioma: a Pediatric Brain Tumor Consortium study

BACKGROUND

A Pediatric Brain Tumor Consortium (PBTC) phase I/II trial of veliparib and radiation followed by veliparib and temozolomide (TMZ) was conducted in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG). The objectives were to: (i) estimate the recommended phase II dose (RP2D) of veliparib with concurrent radiation; (ii) evaluate the pharmacokinetic parameters of veliparib during radiation; (iii) evaluate feasibility of intrapatient TMZ dose escalation; (iv) describe toxicities of protocol therapy; and (v) estimate the overall survival distribution compared with historical series.

METHODS

Veliparib was given Monday through Friday b.i.d. during radiation followed by a 4-week rest. Patients then received veliparib at 25 mg/m2 b.i.d. and TMZ 135 mg/m2 daily for 5 days every 28 days. Intrapatient dose escalation of TMZ was investigated for patients experiencing minimal toxicity.

RESULTS

Sixty-six patients (65 eligible) were enrolled. The RP2D of veliparib was 65 mg/m2 b.i.d. with radiation. Dose-limiting toxicities during radiation with veliparib therapy included: grade 2 intratumoral hemorrhage (n = 1), grade 3 maculopapular rash (n = 2), and grade 3 nervous system disorder (generalized neurologic deterioration) (n = 1). Intrapatient TMZ dose escalation during maintenance was not tolerated. Following a planned interim analysis, it was concluded that this treatment did not show a survival benefit compared with PBTC historical controls, and accrual was stopped for futility. The 1- and 2-year overall survival rates were 37.2% (SE 7%) and 5.3% (SE 3%), respectively.

CONCLUSION

Addition of veliparib to radiation followed by TMZ and veliparib was tolerated but did not improve survival for patients with newly diagnosed DIPG.

TRIAL REGISTRATION

NCT01514201.

Non-invasive Urinary Biomarkers in Moyamoya Disease

Introduction: A major difficulty in treating moyamoya disease is the lack of effective methods to detect novel or progressive disease prior to the onset of disabling stroke. More importantly, a tool to better stratify operative candidates and quantify response to therapy could substantively complement existing methods. Here, we present proof-of-principle data supporting the use of urinary biomarkers as diagnostic adjuncts in pediatric moyamoya patients.

Methods: Urine and cerebrospinal fluid specimens were collected from pediatric patients with moyamoya disease and a cohort of age and sex-matched control patients. Clinical and radiographic data were paired with measurements of a previously validated panel of angiogenic proteins quantified by ELISA. Results were compared to age and sex-matched controls and subjected to statistical analyses.

Results: Evaluation of a specific panel of urinary and cerebrospinal fluid biomarkers by ELISA demonstrated significant elevations of angiogenic proteins in samples from moyamoya patients compared to matched controls. ROC curves for individual urinary biomarkers, including MMP-2, MMP-9, MMP-9/NGAL, and VEGF, showed excellent discrimination. The optimal urinary biomarker was MMP-2, providing a sensitivity of 88%, specificity of 100%, and overall accuracy of 91%. Biomarker levels changed in response to therapy and correlated with radiographic evidence of revascularization.

Conclusions: We report, for the first time, identification of a panel of urinary biomarkers that predicts the presence of moyamoya disease. These biomarkers correlate with presence of disease and can be tracked from the central nervous system to urine. These data support the hypothesis that urinary proteins are useful predictors of the presence of moyamoya disease and may provide a basis for a novel, non-invasive method to identify new disease and monitor known patients following treatment.

Liquid Biomarkers for Pediatric Brain Tumors: Biological Features, Advantages and Perspectives

Tumors of the central nervous system are the most frequent solid tumor type and the major cause for cancer-related mortality in children and adolescents. These tumors are biologically highly heterogeneous and comprise various different entities. Molecular diagnostics are already well-established for pediatric brain tumors and have facilitated a more accurate patient stratification. The availability of targeted, biomarker-driven therapies has increased the necessity of longitudinal monitoring of molecular alterations within tumors for precision medicine-guided therapy. Nevertheless, diagnosis is still primarily based on analyses of the primary tumor and follow-up is usually performed by imaging techniques which lack important information on tumor biology possibly changing the course of the disease. To overcome this shortage of longitudinal information, liquid biopsy has emerged as a promising diagnostic tool representing a less-invasive source of biomarkers for tumor monitoring and therapeutic decision making. Novel ultrasensitive methods for detection of allele variants, genetic alterations with low abundance, have been developed and are promising tools for establishing and integrating liquid biopsy techniques into clinical routine. Pediatric brain tumors harbor multiple molecular alterations with the potential to be used as liquid biomarkers. Consequently, studies have already investigated different types of biomarker in diverse entities of pediatric brain tumors. However, there are still certain pitfalls until liquid biomarkers can be unleashed and implemented into routine clinical care. Within this review, we summarize current knowledge on liquid biopsy markers and technologies in pediatric brain tumors, their advantages and drawbacks, as well as future potential biomarkers and perspectives with respect to clinical implementation in patient care.

Dysregulation of the EphrinB2-EphB4 ratio in pediatric cerebral arteriovenous malformations is associated with endothelial cell dysfunction in vitro and functions as a novel noninvasive biomarker in patients

We investigated (1) EphrinB2 and EphB4 receptor expression in cerebral AVMs, (2) the impact of an altered EphrinB2:EphB4 ratio on brain endothelial cell function and (3) potential translational applications of these data. The following parameters were compared between AVM endothelial cells (AVMECs) and human brain microvascular endothelial cells (HBMVECs): quantified EphrinB2 and EphB4 expression, angiogenic potential, and responses to manipulation of the EphrinB2:EphB4 ratio via pharmacologic stimulation/inhibition. To investigate the clinical relevance of these in vitro data, Ephrin expression was assessed in AVM tissue (by immunohistochemistry) and urine (by ELISA) from pediatric patients with AVM (n = 30), other cerebrovascular disease (n = 14) and control patients (n = 29), and the data were subjected to univariate and multivariate statistical analyses. Compared to HBMVECs, AVMECs demonstrated increased invasion (p = 0.04) and migration (p = 0.08), impaired tube formation (p = 0.06) and increased EphrinB2:EphB4 ratios. Altering the EphrinB2:EphB4 ratio (by increasing EphrinB2 or blocking EphB4) in HBMVECs increased invasion (p = 0.03 and p < 0.05, respectively). EphrinB2 expression was increased in AVM tissue, which correlated with increased urinary EphrinB2 levels in AVM patients. Using the optimal urinary cutoff value (EphrinB2 > 25.7 pg/μg), AVMs were detected with high accuracy (80% vs. controls) and were distinguished from other cerebrovascular disease (75% accuracy). Post-treatment urinary EphrinB2 levels normalized in an index patient. In summary, AVMECs have an EphrinB2:EphB4 ratio that is increased compared to that of normal HBMVECs. Changing this ratio in HBMVECs induces AVMEC-like behavior. EphrinB2 is clinically relevant, and its levels are increased in AVM tissue and patient urine. This work suggests that dysregulation of the EphrinB2:EphB4 signaling cascade and increases in EphrinB2 may play a role in AVM development, with potential utility as a diagnostic and therapeutic target.

Tangled blood vessel growths in the brain, known as arteriovenous malformations (AVMs), can be identified with a urine test, and the test protein may also help in treatment. AVMs often have no symptoms and can go undiagnosed, but when they rupture they can cause deadly brain hemorrhage. Better diagnostic tools and nonsurgical treatments are needed. Katie Fehnel and Edward Smith at Boston Children’s Hospital, USA, and co-workers identified an imbalance in a pair of signal/receptor proteins called ephrins in AVMs. Disturbing the balance of ephrin levels in blood vessel-forming cells disrupted growth, causing disorganized vessel formation with too many sprouts and insufficient junctions. Testing ephrin levels in patients’ urine reliably identified AVMs. These results offer a rapid and noninvasive new diagnostic tool and may help find new treatments for this mostly invisible and potentially fatal condition.

Liquid biopsies for diagnosing and monitoring primary tumors of the central nervous system

Obtaining diagnostic specimens, notably to monitor disease course in cancer patients undergoing therapy, is an emerging area of research, however, with few clinical implications so far in the field of Neuro-oncology. Specifically for patients with primary brain tumors where repeat biosampling from the tumor and clinical decision making based on neuroimaging alone remain challenging, this area may assume a central role. In principle, sampling could focus on blood, cerebrospinal fluid or urine with differential sensitivities and specificities of findings that differ between specific parameters and target molecules. These include protein, mRNA, miRNA, cell-free DNA, either freely circulating or as cargo of extracellular vesicles, as well circulating tumor cells. The most solid biomarkers are those directly reflecting neoplastic disease, e.g., in the case of primary brain tumors isocitrate dehydrogenase mutation or epidermal growth factor receptor variant III. Importantly, the main goals of liquid biopsy marker development are to better understand response to therapy, natural evolution and emergence of resistant clones, rather than obviating the need for surgical interventions which remain to be a mainstay of therapy for the vast majority of primary brain tumors.

Metalloproteinases and their roles in human cancer

It is now widely appreciated that members of the matrix metalloproteinase (MMP) family of enzymes play a key role in cancer development and progression along with many of the hallmarks associated with them. The activity of these enzymes has been directly implicated in extracellular matrix remodeling, the processing of growth factors and receptors, the modulation of cell migration, proliferation, and invasion, the epithelial to mesenchymal transition, the regulation of immune responses, and the control of angiogenesis. Certain MMP family members have been validated as biomarkers of a variety of human cancers including those of the breast, brain, pancreas, prostate, ovary, and others. The related metalloproteinases, the A disintegrin and metalloproteinases (ADAMs), share a number of these functions as well. Here, we explore these essential metalloproteinases and some of their disease-associated activities in detail as well as some of their complementary translational potential. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

Liquid biopsy for pediatric central nervous system tumors

Central nervous system (CNS) tumors are the most common solid tumors in children, and the leading cause of cancer-related death. Over the past decade, molecular profiling has been incorporated into treatment for pediatric CNS tumors, allowing for a more personalized approach to therapy. Through the identification of tumor-specific changes, it is now possible to diagnose, assign a prognostic subgroup, and develop targeted chemotherapeutic treatment plans for many cancer types. The successful incorporation of informative liquid biopsies, where the liquid biome is interrogated for tumor-associated molecular clues, has the potential to greatly complement the precision-based approach to treatment, and ultimately, to improve clinical outcomes for children with CNS tumors. In this article, the current application of liquid biopsy in cancer therapy will be reviewed, as will its potential for the diagnosis and therapeutic monitoring of pediatric CNS tumors.

Circulating serum oncologic miRNA in pediatric juvenile pilocytic astrocytoma patients predicts mural nodule volume

BACKGROUND

Juvenile pilocytic astrocytomas represent the largest group of pediatric brain tumors. The ideal management for these tumors is early, total surgical resection. To detect and track treatment response, a screening tool is needed to identify patients for surgical evaluation and assess the quality of treatment. The identification of aberrant miRNA profiles in the sera of juvenile pilocytic astrocytoma patients could provide such a screening tool.

METHODS

The authors reviewed the serum profiles of 84 oncologically relevant miRNAs in pediatric juvenile pilocytic astrocytoma patients via qPCR screening.

RESULTS

miR-21, miR-15b, miR-23a, and miR-146b were significantly elevated in the sera of JPA patients as compared to non-oncologic controls, oncologic controls, and post-JPA resection samples (p < 0.001, 0.022, 0.034, 0.044). miR-21 had the highest AUC on ROC analysis (AUC > 0.99, sensitivity 75%, specificity 100%). All four miRNAs also correlated well with tumor mural nodule size, though they only poorly correlated with total tumor size, including cystic components (Spearman's R²: miR-21 91.7 vs 6.9%, miR-15b 86.3 vs 23.1%, miR-23a 85.8 vs 23.0%, miR-146b 59.8 vs 11.9%).

CONCLUSION

In this small pilot study, pediatric juvenile pilocytic astrocytoma patients had significant elevations in serum miR-21, miR-15b, miR-23a, and miR-146b levels that do not appear to be driven by hydrocephalus or local distortion of the intracranial contents. These alterations correlate with solid tumor component volume and reverse with complete tumor resection, suggesting that this serum miRNA profile may delineate biomarkers for screening and tracking juvenile pilocytic astrocytoma patients. Additional studies, with a larger cohort, are needed to verify these results.