Concurrent Collection of Fetal Murine Brain and Serum to Assess Effects of Maternal Diet on Nutrition and Neurodevelopment in Neurofibromatosis Type 1.

Maternal diet-induced obesity has been demonstrated to alter neurodevelopment in offspring, which may lead to reduced cognitive capacity, hyperactivity, and impairments in social behavior. Patients with the clinically heterogeneous genetic disorder Neurofibromatosis Type 1 (NF1) may present with similar deficits, but it is currently unclear whether environmental factors such as maternal diet influence the development of these phenotypes, and if so, the mechanism by which such an effect would occur. To enable evaluation of how maternal obesogenic diet exposure affects systemic factors relevant to neurodevelopment in NF1, we have developed a method to simultaneously collect non-hemolyzed serum and whole or regionally micro-dissected brains from fetal offspring of murine dams fed a control diet versus a high-fat, high-sucrose diet. Brains were processed for cryosectioning or flash frozen to use for subsequent RNA or protein isolation; the quality of the collected tissue was verified by immunostaining. The quality of the serum was verified by analyzing macronutrient profiles. Using this technique, we have identified that maternal obesogenic diet increases fetal serum cholesterol similarly between WT and Nf1-heterozygous pups.

Circulating free DNA in the plasma of individuals with neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is an autosomal dominant syndrome whose characteristic manifestations include benign neurofibromas, yet NF1 is also associated with a high risk of cancer. Measurements of circulating free plasma DNA (cfDNA) are gaining wider applicability in cancer diagnostics, targeting of therapy, and monitoring of therapeutic response. Individuals with NF1 are likely to be followed up using this method, but the effects of NF1 and neurofibromas on cfDNA levels are not known. We studied peripheral blood samples from 19 adults with NF1 and 12 healthy controls. The cfDNA was isolated from plasma with QIAamp Circulating Nucleic Acid Kit and quantified using the Qubit 2.0 Fluorometer. The cfDNA concentration of each sample was normalized relative to the plasma protein concentration. The normalized median concentration of cfDNA in plasma was 19.3 ng/ml (range 6.6-78.6) among individuals with NF1 and 15.9 ng/ml (range 4.8-47.0) among controls (p = .369). Individuals with NF1 who also had plexiform neurofibroma (pNF) showed non-significantly elevated cfDNA concentration compared to individuals with NF1 and without known pNF (median 25.4 vs. 18.8 ng/ml, p = .122). The effect of NF1 on cfDNA seems to be relatively small and NF1 is therefore unlikely to hamper the use of cfDNA-based assays.

Serum-derived exosomes from neurofibromatosis type 1 congenital tibial pseudarthrosis impaired bone by promoting osteoclastogenesis and inhibiting osteogenesis.

Treatment of congenital pseudarthrosis of the tibia (CPT) still is full of challenges in pediatric orthopedist. Serum-derived exosomes (SDEs) have been proven to be participated in bone remodeling. However, the molecular changes in SDEs of CPT children and their pathologies have not been elucidated. In this study, SDEs were isolated and purified from CPT patients (CPT-SDEs) associated with neurofibromatosis type 1 (NF1) and normal children (Norm-SDEs). Then we obtained the proteomics profile of SDEs by combining liquid chromatography-tandem mass spectrometry (LC-MS/MS) and tandem mass tag label-based quantitation. In vitro, the efficacy of SDEs on osteoblastic differentiation of MC3T3-E1 cells and osteoclastogenesis ability of RAW264.7 cells were evaluated by quantitative real-time PCR (qRT-PCR) and cytochemical staining. In vivo, we used micro-CT to assess cortical bone mass and trabecular microstructures to reflect the influence of SDEs on bone remodeling after injection into the tail vein of rats. Based on proteomics analysis, 410 differentially expressed proteins, including 289 downregulated proteins and 121 upregulated proteins, were identified in the CPT-SDEs. These proteins have multiple biological functions associated with cellular metabolic processes, catalytic activity, and protein binding, which are important for cell differentiation and proliferation. In vitro, CPT-SDEs decreased the osteogenic differentiation of MC3T3-E1 cells and promoted the osteoclastogenesis of RAW264.7 cells. Injection of CPT-SDEs into the tail vein for two months resulted in bone loss in rats, as indicated by the decrease in trabecular and cortical bone mass. Our findings demonstrated the differences in proteins in SDEs between normal and CPT children with NF1. These differentially expressed proteins in CPT-SDEs contributed to deteriorating trabecular bone microstructures by inhibiting bone formation and stimulating bone resorption.

Systemic Lupus Erythematosus, Evans Syndrome, and Neurofibromatosis: An Unusual Combination in Pediatric Patient.

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organ systems. Patients can have hematologic manifestations, including Evans syndrome (ES), which is characterized by immune-mediated thrombocytopenia and anemia. The association of neurofibromatosis 1 (NF1) with autoimmune disorders is rarely reported. We will review the literature for this combination of disorders and describe a case of a 16-year-old girl who presents with immune-mediated cytopenias and is diagnosed with SLE, ES, and NF1. There are 7 reported cases of SLE and NF1 and only 2 are pediatric cases. There are no reports of the combination of SLE, ES, and NF1.

Dynamic thiol/disulphide homeostasis in children with neurofibromatosis type 1 and tuberous sclerosis.

Neurofibromatosis type 1 (NF1) and tuberous sclerosis (TSC) are autosomal dominant neurocutaneous diseases. Epilepsy, malignancy and other neurological complications are common in both diseases. We aimed to investigate the thiol/disulphide balance as an oxidative stress marker in children who suffer from NF1 and TSC. Twenty-two patients with NF1, 20 TCS, and 22 healthy control subjects were included in the study. The total thiol, native thiol, and disulphide levels were measured and the disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios were calculated and compared in three groups. The mean age and sex distribution of the patients with TSC and NF1 and the healthy control were similar. The total thiol, native thiol, and disulfide level was lower in TSC and NF1 group than the healthy control group. There were no significant differences among disulphide/native thiol and disulphide/total thiol ratios of three groups. We detected that the total thiol, native thiol, and disulfide levels were lower in TSC and NF1 group than the healthy control group. These results indicate that dynamic thiol-disulphide homeostasis can be used as a marker of oxidative stress in clinical trials with TSC and NF1.

Reprogramming Captures the Genetic and Tumorigenic Properties of Neurofibromatosis Type 1 Plexiform Neurofibromas.

Neurofibromatosis type 1 (NF1) is a tumor predisposition genetic disease caused by mutations in the NF1 tumor suppressor gene. Plexiform neurofibromas (PNFs) are benign Schwann cell (SC) tumors of the peripheral nerve sheath that develop through NF1 inactivation and can progress toward a malignant soft tissue sarcoma. There is a lack of non-perishable model systems to investigate PNF development. We reprogrammed PNF-derived NF1(-/-) cells, descendants from the tumor originating cell. These NF1(-/-)-induced pluripotent stem cells (iPSCs) captured the genomic status of PNFs and were able to differentiate toward neural crest stem cells and further to SCs. iPSC-derived NF1(-/-) SCs exhibited a continuous high proliferation rate, poor myelination ability, and a tendency to form 3D spheres that expressed the same markers as their PNF-derived primary SC counterparts. They represent a valuable model to study and treat PNFs. PNF-derived iPSC lines were banked for making them available.

Ultra-deep amplicon sequencing indicates absence of low-grade mosaicism with normal cells in patients with type-1 NF1 deletions.

Different types of large NF1 deletion are distinguishable by breakpoint location and potentially also by the frequency of mosaicism with normal cells lacking the deletion. However, low-grade mosaicism with fewer than 10% normal cells has not yet been excluded for all NF1 deletion types since it is impossible to assess by the standard techniques used to identify such deletions, including MLPA and array analysis. Here, we used ultra-deep amplicon sequencing to investigate the presence of normal cells in the blood of 20 patients with type-1 NF1 deletions lacking mosaicism according to MLPA. The ultra-deep sequencing entailed the screening of 96 amplicons for heterozygous SNVs located within the NF1 deletion region. DNA samples from three previously identified patients with type-2 NF1 deletions and low-grade mosaicism with normal cells as determined by FISH or microsatellite marker analysis were used to validate our methodology. In these type-2 NF1 deletion samples, proportions of 5.3%, 6.6% and 15.0% normal cells, respectively, were detected by ultra-deep amplicon sequencing. However, using this highly sensitive method, none of the 20 patients with type-1 NF1 deletions included in our analysis exhibited low-grade mosaicism with normal cells in blood, thereby supporting the view that the vast majority of type-1 deletions are germline deletions.

[A case of growth hormone deficiency combined with neurofibromatosis Type 1 and its gene analysis].

Neurofibromatosis Type 1 (NF1) is an autosomal dominant genetic disorder caused by NF1 gene mutations. Café au lait spots, neurofibromatosis, Lisch nodules, axillary freckling, dermal neurofibromas and skeletal dysplasia are the most common manifestations for this disease. A 11-year-old boy visited Third Xiangya Hospital, Central South University due to growth-retardation. He was eventually diagnosed as NF1 with growth hormone deficiency. A novel heterozygous splicing mutation c.6579+2 T>C (IVS 34+2 T>C) of NF1 gene was identified in the patient and his mother. Considering NF1 may present with short stature due to growth hormone deficiency, all children with short stature combined with café au lait spots should be screened for NF1, which may assist the clinical diagnosis and the genetic counseling.

Increased insulin sensitivity in individuals with neurofibromatosis type 1.

Objects To compare insulin resistance (IR) and metabolic aspects of patients with neurofibromatosis type 1 (NF1) and individuals without the disease. Subjects and methods Forty patients with NF1 were matched by sex, age, and body mass index (BMI) to 40 controls from the community. Blood samples were collected for biochemical assessment. Homeostasis model assessment adiponectin (HOMA-AD), Homeostasis model assessment insulin resistance (HOMA-IR), and adiponectin/leptin ratio (ALR) were used to identify IR. Results The median HOMA-IR values were similar between the groups. However, the HOMA-AD value was significantly lower and the ALR significantly higher in the NF1 group. Fasting blood glucose (FBG), leptin, and visfatin levels of patients with NF1 were significantly lower, although adiponectin levels were significantly higher than those in the controls. Fasting insulin and blood glucose levels 2 hours after administration of 75 g of dextrose, glycated hemoglobin, and resistin showed no significant differences between groups. The HOMA-AD correlated with BMI, FBG, blood glucose levels 2 hours after administration of 75 g of dextrose, fasting insulin, glycated hemoglobin, adiponectin, leptin, visfatin, ALR, and HOMA-IR. The ALR correlated with BMI leptin, visfatin, and adiponectin. Conclusions Lower levels of FBG, leptin, visfatin, and HOMA-AD, and higher adiponectin levels and ALR may be related to increased insulin sensitivity and lower occurrence of type 2 diabetes mellitus in patients with NF1.

Non-invasive prenatal diagnosis of paternally inherited disorders from maternal plasma: detection of NF1 and CFTR mutations using droplet digital PCR.

BACKGROUND: To limit risks of miscarriages associated with invasive procedures of current prenatal diagnosis practice, we aim to develop a personalized medicine-based protocol for non-invasive prenatal diagnosis (NIPD) of monogenic disorders relying on the detection of paternally inherited mutations in maternal blood using droplet digital PCR (ddPCR). METHODS: This study included four couples at risk of transmitting paternal neurofibromatosis type 1 (NF1) mutations and four couples at risk of transmitting compound heterozygous CFTR mutations. NIPD was performed between 8 and 15 weeks of gestation, in parallel to conventional invasive diagnosis. We designed specific hydrolysis probes to detect the paternal mutation and to assess the presence of cell-free fetal DNA by ddPCR. Analytical performances of each assay were determined from paternal sample, an then fetal genotype was inferred from maternal plasma sample. RESULTS: Presence or absence of the paternal mutant allele was correctly determined in all the studied plasma DNA samples. CONCLUSIONS: We report an NIPD protocol suitable for implementation in an experienced laboratory of molecular genetics. Our proof-of-principle results point out a high accuracy for early detection of paternal NF1 and CFTR mutations in cell-free DNA, and open new perspectives for extending the technology to NIPD of many other monogenic diseases.

Randomised controlled trial of simvastatin treatment for autism in young children with neurofibromatosis type 1 (SANTA).

Background: Neurofibromatosis 1 (NF1) is a monogenic model for syndromic autism. Statins rescue the social and cognitive phenotype in animal knockout models, but translational trials with subjects > 8 years using cognition/behaviour outcomes have shown mixed results. This trial breaks new ground by studying statin effects for the first time in younger children with NF1 and co-morbid autism and by using multiparametric imaging outcomes. Methods: A single-site triple-blind RCT of simvastatin vs. placebo was done. Assessment (baseline and 12-week endpoint) included peripheral MAPK assay, awake magnetic resonance imaging spectroscopy (MRS; GABA and glutamate+glutamine (Glx)), arterial spin labelling (ASL), apparent diffusion coefficient (ADC), resting state functional MRI, and autism behavioural outcomes (Aberrant Behaviour Checklist and Clinical Global Impression). Results: Thirty subjects had a mean age of 8.1 years (SD 1.8). Simvastatin was well tolerated. The amount of imaging data varied by test. Simvastatin treatment was associated with (i) increased frontal white matter MRS GABA (t(12) = - 2.12, p = .055), GABA/Glx ratio (t(12) = - 2.78, p = .016), and reduced grey nuclei Glx (ANCOVA p < 0.05, Mann-Whitney p < 0.01); (ii) increased ASL perfusion in ventral diencephalon (Mann-Whitney p < 0.01); and (iii) decreased ADC in cingulate gyrus (Mann-Whitney p < 0.01). Machine-learning classification of imaging outcomes achieved 79% (p < .05) accuracy differentiating groups at endpoint against chance level (64%, p = 0.25) at baseline. Three of 12 (25%) simvastatin cases compared to none in placebo met 'clinical responder' criteria for behavioural outcome. Conclusions: We show feasibility of peripheral MAPK assay and autism symptom measurement, but the study was not powered to test effectiveness. Multiparametric imaging suggests possible simvastatin effects in brain areas previously associated with NF1 pathophysiology and the social brain network. Trial registration: EU Clinical Trial Register (EudraCT) 2012-005742-38 (www.clinicaltrialsregister.eu).

Intraductal papillary bile duct adenocarcinoma and gastrointestinal stromal tumor in a case of neurofibromatosis type 1.

We report our experience with a synchronous case of gastrointestinal stromal tumor (GIST) and intraductal papillary neoplasm of the bile duct (IPNB) in an elderly woman with neurofibromatosis type 1 (NF-1). A 72-year-old woman presented with a 2-mo history of right upper abdominal pain unrelated to diet and indigestion. Fourteen years earlier, she had been diagnosed with NF-1, which manifested as café au lait spots and multiple nodules on the skin. Computed tomography (CT) revealed a multilocular low-density mass with septation, and mural nodules in the right hepatic lobe, as well as a 1.7-cm-sized well-demarcated enhancing mass in the third portion of the duodenum. The patient subsequently underwent right hepatectomy and duodenal wedge resection. We present here the first report of a case involving a synchronous IPNB and GIST in a patient with NF-1. Our findings demonstrate the possibility of various tumors in NF-1 patients and the importance of diagnosis at an early stage.

Increased insulin sensitivity in individuals with neurofibromatosis type 1

ABSTRACT Objects To compare insulin resistance (IR) and metabolic aspects of patients with neurofibromatosis type 1 (NF1) and individuals without the disease. Subjects and methods Forty patients with NF1 were matched by sex, age, and body mass index (BMI) to 40 controls from the community. Blood samples were collected for biochemical assessment. Homeostasis model assessment adiponectin (HOMA-AD), Homeostasis model assessment insulin resistance (HOMA-IR), and adiponectin/leptin ratio (ALR) were used to identify IR. Results The median HOMA-IR values were similar between the groups. However, the HOMA-AD value was significantly lower and the ALR significantly higher in the NF1 group. Fasting blood glucose (FBG), leptin, and visfatin levels of patients with NF1 were significantly lower, although adiponectin levels were significantly higher than those in the controls. Fasting insulin and blood glucose levels 2 hours after administration of 75 g of dextrose, glycated hemoglobin, and resistin showed no significant differences between groups. The HOMA-AD correlated with BMI, FBG, blood glucose levels 2 hours after administration of 75 g of dextrose, fasting insulin, glycated hemoglobin, adiponectin, leptin, visfatin, ALR, and HOMA-IR. The ALR correlated with BMI leptin, visfatin, and adiponectin. Conclusions Lower levels of FBG, leptin, visfatin, and HOMA-AD, and higher adiponectin levels and ALR may be related to increased insulin sensitivity and lower occurrence of type 2 diabetes mellitus in patients with NF1

Growth Hormone Excess in Children with Optic Pathway Tumors Is a Transient Phenomenon.

BACKGROUND/AIMS: Growth hormone (GH) excess in children with chiasmal optic pathway tumors (OPT), often associated with neurofibromatosis type 1 (NF1), is likely underrecognized. These children have elevated insulin-like growth factor 1 (IGF-1) levels, evidence of rapid growth despite treatment of precocious puberty, and failure to suppress GH levels following oral glucose challenge. The aim of this report is to describe the treatment course and natural history of this rare clinical condition in 7 patients. METHODS: This is a descriptive case series of 5 children previously described and 2 additional children more recently diagnosed at our institution. All 7 children had clinical and biochemical evidence of GH excess and received treatment with the somatostatin analog octreotide. RESULTS: Length of treatment varied among the patients. Five of the 7 patients have had resolution of GH excess and currently have normal IGF-1 levels without treatment. CONCLUSIONS: Unrestrained GH secretion occurs in a subset of children with OPT with potential adverse outcomes. Since GH excess appears to resolve over time, the benefit of treatment to alter outcomes or prevent tumor progression is unclear.

Nutritional, muscular and metabolic characteristics in patients with neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) has many reported clinical characteristics. We previously found that NF1 patients (especially men) had lower body mass index (BMI) than controls, but the reason has not been elucidated. To address this issue, a retrospectively case-control study was conducted. Anthropometric and serum chemistry data that potentially relate to BMI were collected from medical records of NF1 patients and their age- and sex-matched controls. Enrollment of 98 adult patients who underwent skin surgery with NF1 (41 men, 57 women) and 173 without NF1 (74 men, 99 women) were investigated. The median BMI in male NF1 patients was significantly lower than that of the controls. Triglycerides in male NF1 patients were significantly lower than male controls, creatine kinase and lactate dehydrogenase in NF1 patients were also lower than controls, aspartate aminotransferase and alanine aminotransferase showed a lower tendency in NF1 patients, but were significantly lower in female patients. With correlation analysis, lactate dehydrogenase was moderately correlated with BMI in male NF1 patients. Creatine kinase and creatinine showed no statistical correlation with BMI in either group. Triglycerides and alanine aminotransferase showed a positive correlation with BMI in both male and female controls, but not in NF1 patients. In conclusion, only lactate dehydrogenase was moderately correlated with BMI in male NF1 patients, although results of some nutritional and metabolic parameters suggest a specific metabolism in NF1.

Vascular Innervation in Benign Neurofibromas of Patients with Neurofibromatosis Type 1.

UNLABELLED: Neurofibroma constitutes a heterogeneous group of solid tumours occurring sporadically or in association with syndromes. The aspect of these peripheral nerve sheath tumours may vary considerably, with disseminated tumours covering various parts of the body or nodular/diffuse plexiform neurofibroma that can grow to an impressive size. Although neurofibromas have vascular density comparable to that of normal tissue, they have tendency to bleed upon surgery which is poorly understood. Herein we investigated whether this finding may result from alterations of peripheral vasculature innervation. Different types of neurofibroma and controls were evaluated with special reference to nerve fibre topography and vessel density. MATERIALS AND METHODS: Seventy-six formalin-fixed and paraffin-embedded tissue samples (63 neurofibromas and 13 skin biopsies) were retrieved from the archives of the Institute of Neuropathology, University Medical Center Hamburg-Eppendorf. Nerve fibres and blood vessels were differentiated immunohistochemically on 10-µm-thick tumour slices using antibodies against smooth muscle actin (arteries), protein gene product 9.5 (PGP9.5) and neurofilament (nerve fibres). Skin samples served as controls. Nerve fibre and vessel densities were quantified morphometrically. RESULTS: Nerve fibre density varied considerably. However, vascular innervation did not statistically significantly differ between the different tumour sub-groups and controls. Vessel density was not significantly increased in tumours compared to skin biopsies. Within the tumour sub-groups, diffuse plexiform neurofibroma presented a significantly higher vascular density than atypical neurofibroma (p=0.006). CONCLUSION: Blood vessel density and vascular innervation in the whole cohort of neurofibromas did not significantly differ from that of controls. Thus, the source of prolonged and intense bleeding of neurofibroma during surgical procedures cannot be explained by increased vessel density or loss of innervation, but may be attributed to other factors such as alterations in the structure of the vascular wall.

Age-dependent changes in sirolimus metabolite formation in patients with neurofibromatosis type 1.

BACKGROUND: Sirolimus is an inhibitor of mammalian target of rapamycin, which exhibits large interindividual pharmacokinetic variability. We report sirolimus pharmacokinetic data collected as part of a concentration-controlled multicenter phase II clinical trial in pediatric patients with neurofibromatosis type 1. The purpose of this study was to explore the effect of growth on age-dependent changes in sirolimus clearance with a focus on cytochrome P450 3A (CYP3A) subfamily mediated metabolism. METHODS: Predose blood samples were obtained at steady state from 18 patients with neurofibromatosis type 1. Sirolimus and its 5 CYP3A-dependent primary metabolites were quantified by HPLC-UV/MS. Concentration ratios of metabolites to sirolimus (metabolic ratio) were calculated as an index of metabolite formation. RESULTS: Metabolic ratios of the main metabolites, 16-O-demethylsirolimus (16-O-DM) and 24-hydroxysirolimus (24OH), were significantly correlated with sirolimus clearance, whereas this was not the case for the other 3 metabolites (25-hydroxysirolimus, 46-hydroxysirolimus, and 39-O-demethylsirolimus). The ratios for the 16-O-DM and 24OH metabolites were lower in children than adults. No significant difference in allometrically scaled metabolic ratios of 16-O-DM and 24OH was observed between children and adults. CONCLUSIONS: This study suggests that the age-dependent changes in sirolimus clearance can be explained by size-related increases in CYP3A metabolic capacity, most likely due to liver and intestinal growth. These findings will help facilitate the development of age-appropriate dosing algorithms for sirolimus in infants and children.

Differences of 25-hydroxyvitamin D3 concentrations in children and adults with neurofibromatosis type 1.

OBJECTIVES: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, frequently associated with reduced bone mineral density. Serum 25-hydroxyvitamin D3 concentrations in NF1 adults are lower than in healthy controls in autumn respectively winter and are inversely correlated with the number of dermal neurofibromas. We investigated 25-hydroxyvitamin D3 levels in children and adults with neurofibromatosis type 1 in winter and summer and compared them to healthy controls to get more pathogenic insights in vitamin D3 metabolism in NF1 patients. DESIGN AND METHODS: NF1 patients were clinically examined and serum 25-hydroxyvitamin D3 concentrations were measured in 58 NF1 adults and 46 children in winter as well as in summer and compared to sex-, age- and month-matched controls. RESULTS: 52 adults suffered from 10 to 5000 dermal neurofibromas, whereas none of the children presented neurofibromas. 25-Hydroxyvitamin D3 increased from winter to summer (mean: 21.0 to 46.5nmol/l) in NF1 adults. This increase was even larger (p=0.0001) than in healthy controls (mean: 50.5 to 60.5nmol/l). However, there were no differences of 25-hydroxyvitamin D3 concentrations in NF1 children and healthy controls both in winter and in summer. CONCLUSIONS: Only adults with NF1 showed lower 25-hydroxyvitamin D3 levels in winter and summer, which are unlikely due to impaired UV-dependent dermal synthesis, but rather might be caused by an accelerated catabolism.

Soluble AXL: a possible circulating biomarker for neurofibromatosis type 1 related tumor burden.

Neurofibromatosis type 1 (NF1) is the most common tumor predisposition disorder affecting 1/3500 worldwide. Patients are at risk of developing benign (neurofibromas) and malignant peripheral nerve sheath tumors (MPNST). The AXL receptor tyrosine kinase has been implicated in several kinds of cancers, but so far no studies have investigated the role of AXL in NF1 related tumorigenesis. Recently, the soluble fraction from the extracellular domain of AXL (sAXL) has been found in human plasma, and its level was correlated to poor prognosis in patients with renal cancer. Compared to normal human Schwann cells, a significantly high expression level of AXL was found in three of the four MPNST cell lines and two of the three primary MPNST tissues. Similarly, the level of sAXL in conditioned media corresponded to the protein and mRNA levels of AXL in the MPNST cell lines. Furthermore, in two different human MPNST xenograft models, the human sAXL could be detected in the mouse plasma. Its level was proportionate to the size of the xenograft tumors, while no human sAXL was detect prior to the formation of the tumors. Treatment with a newly developed photodynamic therapy, prevented further tumor growth and resulted in drastically reduced the levels of sAXL compared to that of the control group. Finally, the level of sAXL was significantly increased in patients with plexiform tumors compared to patients with only dermal neurofibromas, further supporting the role of sAXL as a marker for NF1 related tumor burden.

Narrowband ultraviolet B irradiation increases the serum level of vitamin D3 in patients with neurofibromatosis 1.

The serum vitamin D3 levels in patients with neurofibromatosis 1 has been reported to be significantly lower than that in control subjects, and the level of vitamin D3 reversely correlates with the severity of neurofibroma formation. We found that narrowband ultraviolet B (NB-UVB) irradiation increased the serum level of 1,25(OH)2 vitamin D3 in patients with neurofibromatosis 1. The difference in the 1,25(OH)2 vitamin D3 levels between patients who had received irradiation for more than 18 months and those who had no irradiation was highly significant. Time-course analyses of the serum vitamin D3 levels in the patients who were enrolled after informed consent revealed that the levels became higher significantly after 6 months of irradiation. It is suggested that NB-UVB irradiation is effective for increasing the serum level of vitamin D3 in patients with neurofibromatosis 1, which may be of benefit for skin symptoms such as pigmented macules or neurofibromas.