Enhancer reprogramming in PRC2-deficient malignant peripheral nerve sheath tumors induces a targetable de-differentiated state.

Malignant peripheral nerve sheath tumors (MPNSTs) are soft tissue sarcomas that frequently harbor genetic alterations in polycomb repressor complex 2 (PRC2) components-SUZ12 and EED. Here, we show that PRC2 loss confers a dedifferentiated early neural-crest phenotype which is exclusive to PRC2-mutant MPNSTs and not a feature of neurofibromas. Neural crest phenotype in PRC2 mutant MPNSTs was validated via cross-species comparative analysis using spontaneous and transgenic MPNST models. Systematic chromatin state profiling of the MPNST cells showed extensive epigenomic reprogramming or chromatin states associated with PRC2 loss and identified gains of active enhancer states/super-enhancers on early neural crest regulators in PRC2-mutant conditions around genomic loci that harbored repressed/poised states in PRC2-WT MPNST cells. Consistently, inverse correlation between H3K27me3 loss and H3K27Ac gain was noted in MPNSTs. Epigenetic editing experiments established functional roles for enhancer gains on DLX5-a key regulator of neural crest phenotype. Consistently, blockade of enhancer activity by bromodomain inhibitors specifically suppressed this neural crest phenotype and tumor burden in PRC2-mutant PDXs. Together, these findings reveal accumulation of dedifferentiated neural crest like state in PRC2-mutant MPNSTs that can be targeted by enhancer blockade.

Inhibition of JNJ-26481585-mediated autophagy induces apoptosis via ROS activation and mitochondrial membrane potential disruption in neuroblastoma cells.

Neuroblastoma (NB) is the common pediatric tumor of the sympathetic nervous system characterized by poor prognosis. Owing to the challenges such as high tumor heterogeneity, multidrug resistance, minimal residual disease, etc., there is an immediate need for exploring new therapeutic strategies and effective treatments for NB. Herein, in the current study, we explored the unexplored response of NB cells to the second-generation histone deacetylase inhibitor (HDACi) JNJ-26481585(JNJ) and the lysosomotropic agent, Chloroquine (CQ) alone and upon JNJ/CQ treatment as a plausible therapeutic. We identify that while JNJ alone induced autophagy in NB cells, JNJ/CQ treatment decreased the viability and proliferation of NB cells in vitro by switching from autophagy to apoptosis. Further we found that autophagy inhibition by CQ pre-treatment led to the generation of ROS and a decrease in the mitochondrial membrane potential (MMP) that subsequently caused caspase-3-mediated apoptotic cell death in NB cells. Corroborating the above observations, we found that the ROS scavenger N-acetylcysteine (NAC) countered caspase-3 activity and the cells were rescued from apoptosis. Finally, these observations establish that JNJ/CQ treatment resulted in cell death in NB cells by triggering the formation of ROS and disruption of MMP, suggesting that modulation of JNJ-induced autophagy by CQ represents a promising new therapeutic approach in NB.

Multiple secondary cauda equina non-Hodgkin's lymphoma: a case report and literature review.

BACKGROUND: Secondary central nervous system involvement of non-Hodgkin's lymphoma (NHL) is rare and with poor prognosis, the most common pathological type is diffuse large B cell lymphoma (DLBCL). Although it can occur in any part of central nervous system, it rarely directly infiltrates the spinal cord or cauda equina. CASE PRESENTATION: We present the case of 64-year-old immunocompetent man with a worsening pain of waist and left lower extremity, accompanied by numbness and paresis of bilateral lower extremity for 20 days. His previous medical history included a resection of painless mass in the left groin in another hospital 7 months ago, and the pathological diagnosis was non-Hodgkin small B cell lymphoma. Gd-enhanced MRI and F-18 FDG PET-CT scan demonstrated multiple infiltrations in the cauda equina. During the operation, we removed as many as 11 subdural-extramedullary bean-size lesions involving multiple nerve roots. The paralysis of his left leg recovered rapidly after the operation. During the follow-up period of more than one year, he underwent standard R-CHOP chemical therapy, no evidence of recurrence was noted until the 13th month, the patient died because of intracranial relapse. CONCLUSIONS: Imaging examination is important in the diagnosis of multiple secondary cauda equina non-Hodgkin's lymphoma, and we highlight the significance of gadolinium-enhanced MRI and F-18 FDG-PET/CT in preoperative diagnosis as well as the previous history.

Molecular mechanisms and therapeutic targets in neuroblastoma.

Neuroblastoma is the most common extracranical tumor of childhood and the most deadly tumor of infancy. It is characterized by early age onset and high frequencies of metastatic disease but also the capacity to spontaneously regress. Despite intensive therapy, the survival for patients with high-risk neuroblastoma and those with recurrent or relapsed disease is low. Hence, there is an urgent need to develop new therapies for these patient groups. The molecular pathogenesis based on high-throughput omics technologies of neuroblastoma is beginning to be resolved which have given the opportunity to develop personalized therapies for high-risk patients. Here we discuss the potential of developing targeted therapies against aberrantly expressed molecules detected in sub-populations of neuroblastoma patients and how these selected targets can be drugged in order to overcome treatment resistance, improve survival and quality of life for these patients and also the possibilities to transfer preclinical research into clinical testing.

Posterior Tibial Nerve Lymphoma Presenting as Tarsal Tunnel Syndrome: A Case Report.

We report a case of isolated posterior tibial B-cell lymphoma of the posterior tibial nerve presenting as tarsal tunnel syndrome. This diagnosis was considered because of the clinical presentation and electrophysiologic abnormalities. It was further confirmed by the magnetic resonance imaging findings of the ankle and tissue pathologic findings. Whole body positron emission tomography confirmed this to be a localized lymphoma involving the peripheral nerve. The patient underwent chemotherapy with complete tumor resolution. She had had no relapse after 8 months of follow-up. Isolated peripheral nerve lymphomas are very rare, and involvement of the posterior tibial nerve has not been previously reported. Furthermore, the present case report highlights the importance of the clinical examination in the diagnosis of tarsal tunnel syndrome before performing surgical decompression.

Anti-VEGF treatment improves neurological function in tumors of the nervous system.

Research of various diseases of the nervous system has shown that VEGF has direct neuroprotective effects in the central and peripheral nervous systems, and indirect effects on improving neuronal vessel perfusion which leads to nerve protection. In the tumors of the nervous system, VEGF plays a critical role in tumor angiogenesis and tumor progression. The effect of anti-VEGF treatment on nerve protection and function has been recently reported - by normalizing the tumor vasculature, anti-VEGF treatment is able to relieve nerve edema and deliver oxygen more efficiently into the nerve, thus reducing nerve damage and improving nerve function. This review aims to summarize the divergent roles of VEGF in diseases of the nervous system and the recent findings of anti-VEGF therapy in nerve damage/regeneration and function in tumors, specifically, in Neurofibromatosis type 2 associated schwannomas.

Reduced RAC1 activity inhibits cell proliferation and induces apoptosis in neurofibromatosis type 2(NF2)-associated schwannoma.

Objective To study the function and potential mechanism of RAC1 inhibitors in NF2-associated schwannoma. Methods In this study, we the downregulation of RAC1 activity and tumor cell phenotypes by RAC1 inhibitor NSC23766 in vitro. And we further validated the anti-proliferation effect by this RAC1 inhibitor in subcutaneous xenograft tumor model and sciatic nerve model. Results Pharmacological inhibition of RAC1 could significantly inhibit the proliferation of both RT4 cells and human NF2-associated primary schwannoma cells by inducing apoptosis. Pharmacological inhibition of RAC1 effectively reduced Rac1 activity and down-regulated the pathway downstream of Rac. Moreover, pharmacological inhibition of RAC1 showed a potential antitumor effect, with low toxicity in vivo. Conclusion RAC1 inhibitors may play a therapeutic role in patients with schwannoma.

Corticosteroid Injection for the Treatment of Morton's Neuroma: A Prospective, Double-Blinded, Randomized, Placebo-Controlled Trial.

BACKGROUND: The effectiveness of corticosteroid injection for the treatment of Morton's neuroma is unclear. In addition, most of the studies related to it are case-control or retrospective case series. The purpose of this study was to compare the effectiveness between corticosteroid injection associated with local anesthetic and local anesthetic alone (placebo control group) for the treatment of Morton's neuroma. METHODS: Forty-one patients with a diagnosis of Morton's neuroma were randomized to receive 3 injections of either a corticosteroid plus a local anesthetic or a local anesthetic alone. The patients and the researcher who collected data were blinded to the treatment groups. The visual analog scale for pain and the American Orthopaedic Foot & Ankle Score (metatarsophalangeal/interphalangeal score) were obtained at baseline, after each injection, and at 3 and 6 months after the last injection. RESULTS: There were no significant between-group differences in terms of pain and function improvement at 3 and 6 months after treatment completion in comparison with baseline values. At the end of the study, 17 (48.5%) patients requested surgical excision of the neuroma: 7 (44%) in the experimental group and 10 (53%) in the control group ( P = 1.0). CONCLUSION: The injection of a corticosteroid plus a local anesthetic was not superior to a local anesthetic alone in terms of pain and function improvement in patients with Morton's neuroma. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

An inflammatory gene signature distinguishes neurofibroma Schwann cells and macrophages from cells in the normal peripheral nervous system.

Neurofibromas are benign peripheral nerve tumors driven by NF1 loss in Schwann cells (SCs). Macrophages are abundant in neurofibromas, and macrophage targeted interventions may have therapeutic potential in these tumors. We generated gene expression data from fluorescence-activated cell sorted (FACS) SCs and macrophages from wild-type and mutant nerve and neurofibroma to identify candidate pathways involved in SC-macrophage cross-talk. While in 1-month-old Nf1 mutant nerve neither SCs nor macrophages significantly differed from their normal counterparts, both macrophages and SCs showed significantly altered cytokine gene expression in neurofibromas. Computationally reconstructed SC-macrophage molecular networks were enriched for inflammation-associated pathways. We verified that neurofibroma SC conditioned medium contains macrophage chemo-attractants including colony stimulation factor 1 (CSF1). Network analysis confirmed previously implicated pathways and predict novel paracrine and autocrine loops involving cytokines, chemokines, and growth factors. Network analysis also predicted a central role for decreased type-I interferon signaling. We validated type-I interferon expression in neurofibroma by protein profiling, and show that treatment of neurofibroma-bearing mice with polyethylene glycolyated (PEGylated) type-I interferon-α2b reduces the expression of many cytokines overexpressed in neurofibroma. These studies reveal numerous potential targetable interactions between Nf1 mutant SCs and macrophages for further analyses.

Corticosteroid injection for Morton's neuroma with or without ultrasound guidance: a randomised controlled trial.

AIMS: The objective of this double-blind randomised controlled trial was to assess whether ultrasound guidance improved the efficacy of corticosteroid injections for Morton's neuroma (MN). PATIENTS AND METHODS: In all, 50 feet (40 patients) were recruited for this study but five feet were excluded due to the patients declining further participation. The mean age of the remaining 36 patients (45 feet) was 57.8 years (standard deviation (sd) 12.9) with a female preponderance (33F:12M). All patients were followed-up for 12 months. Treatment was randomised to an ultrasound guided (Group A) or non-ultrasound guided (Group B) injection of 40 mg triamcinolone acetonide and 2 ml 1% lignocaine, following ultrasound confirmation of the diagnosis. RESULTS: The mean visual analogue score for pain improved significantly in both groups (Group A - from 64 mm, sd 25 mm to 29 mm, sd 27; Group B - from 69 mm, sd 23 mm to 37 mm, sd 25) with no statistical difference between them at all time-points. The failure rate within 12 months of treatment was 11/23 (48%) and 12/22 (55%) in Groups A and B, respectively (p = 0.458). The improvement in Manchester Oxford Foot Questionnaire Index and patient satisfaction favoured Group A in the short-term (three months) that almost reached statistical significance (p = 0.059 and 0.066 respectively). However, this difference was not observed beyond three months. CONCLUSION: This study has shown that ultrasound guidance did not demonstrably improve the efficacy of corticosteroid injections in patients with MN. TAKE HOME MESSAGE: In the presence of a clear diagnosis of MN, a trained clinician who understands the forefoot anatomy may perform an injection without ultrasound guidance with good and safe results.

Diffuse large B-cell lymphoma of the cauda equina.

Primary central nervous system (CNS) lymphoma is a rare form of non-Hodgkin's lymphoma. The clinical presentation is variable, depending on its localisation within the nervous system. Only 1% of primary CNS lymphoma emerges in the spinal cord, and the prevalence of primary lymphoma of the cauda equina is unknown, but probably even rarer. Diagnosing primary lymphoma of the cauda equina is difficult, since it can mimic other more common disorders such as a herniated disc, especially in its early stages. Here we present two cases of primary cauda equina lymphoma in which diagnostic work up took a long time, as the final diagnosis was only reached after a nerve root biopsy.

Effects of alcohol injection in rat sciatic nerve as a model for Morton's neuroma treatment.

BACKGROUND: Previous studies have shown that the injection of dehydrated alcohol has been successful for the treatment of Morton's neuroma in the foot. In this study, we determined the cellular effect of injection of alcohol into and around the sciatic nerve of rats and measured the extent of cell necrosis and/or any associated histologic or inflammatory changes. METHODS: Twenty-two male (~375 g) Wistar rats were randomized into 2 groups each receiving alcohol injections into or around the sciatic nerve after nerve exposure under sterile technique. Group 1 rats were injected with a 0.5 ml solution of 0.5% Marcaine in the left sciatic nerve as a control group. In the right sciatic nerve a 0.5 ml solution of 4% ethanol with 0.5% Marcaine was injected. Group 2 rats received 0.5 ml of 20% ethanol with 0.5% Marcaine injected into the left sciatic nerve and 0.5 ml of 30% ethanol with 0.5% Marcaine injected into the right sciatic nerve. In each group, the rats were placed in 3 subgroups: intraneural, perineural, perimuscular injections. All rats were sacrificed and tissue harvested for histologic evaluation at day 10 post injection. RESULTS: No evidence of alcohol-associated cell necrosis, apoptosis, or apparent inflammation was observed in histologic specimens of any injected nerves, perineural tissue, or muscles in controls or experimental groups regardless of concentration of ethanol injected on day 10. CONCLUSION: We concluded that alcohol injection (≤30% ethanol) into and/or around the sciatic nerve or the adjacent muscle of rats has no histologic evidence of necrosis or inflammation to the nerve or surrounding tissue. There was no observable histological change in apoptosis, or cell number, in response to the alcohol injection. CLINICAL RELEVANCE: The lack of any measureable changes in nerve or adjacent muscle histology with ethanol injection into the rat sciatic nerve (and surrounding tissues) raises questions about the efficacy of using ethanol injections in the treatment of Morton's neuroma in human clinical practice.

Primary neurolymphomatosis diagnosis and treatment: a retrospective study.

BACKGROUND: To discuss the therapeutic approach for primary neurolymphomatosis. METHODS: We report all primary neurolymphomatosis cases referred to our institution, with descriptions of clinical, radiological, electrophysiological, histological features and long-term follow-up. We treated all patients with a combination of high-dose methotrexate and alkylating agents. RESULTS: Five patients were diagnosed with histologically confirmed primary neurolymphomatosis. The majority of them presented with painful asymmetric sensory-motor neuropathy. Magnetic resonance imaging was abnormal in 4 of 5 patients, as shown with gadolinium enhancements. Electroneuromyography revealed denervation in all 4 cases with contributive examinations. All our patients received a chemotherapy combination of high-dose methotrexate and alkylating agent. Median progression-free survival was 8 months (2 complete responses and 2 partial responses), and overall survival was 24 months. CONCLUSIONS: Primary neurolymphomatosis is rare and polymorphic; it represents a difficult diagnosis of neuropathy. In our cohort, treatment with a chemotherapy combination with high-dose methotrexate showed encouraging results.

Preclinical evaluation of the combination of mTOR and proteasome inhibitors with radiotherapy in malignant peripheral nerve sheath tumors.

About one half of malignant peripheral nerve sheath tumors (MPNST) have Neurofibromin 1 (NF1) mutations. NF1 is a tumor suppressor gene essential for negative regulation of RAS signaling. Survival for MPNST patients is poor and we sought to identify an effective combination therapy. Starting with the mTOR inhibitors rapamycin and everolimus, we screened for synergy in 542 FDA approved compounds using MPNST cells with a native NF1 loss in both alleles. We further analyzed the cell cycle and signal transduction. In vivo growth effects of the drug combination with local radiation therapy (RT) were assessed in MPNST xenografts. The synergistic combination of mTOR inhibitors with bortezomib yielded a reduction in MPNST cell proliferation. The combination of mTOR inhibitors and bortezomib also enhanced the anti-proliferative effect of radiation in vitro. In vivo, the combination of mTOR inhibitor (everolimus) and bortezomib with RT decreased tumor growth and proliferation, and augmented apoptosis. The combination of approved mTOR and proteasome inhibitors with radiation showed a significant reduction of tumor growth in an animal model and should be investigated and optimized further for MPNST therapy.

Malignant solitary fibrous tumor of the lumbar spinal root mimicking schwannoma: a case report.

BACKGROUND CONTEXT: Malignant solitary fibrous tumors (SFTs) arising from the spinal cord are extremely rare and poorly understood mesenchymal neoplasms. To date, only one malignant SFT located in the spinal canal of the sacrum has been described, but none arising from the lumbar nerve root have been reported. Although most SFTs with benign histological features can be treated by complete surgical excision alone, malignant SFTs may require adjuvant therapy. However, systemic chemotherapy and radiotherapy have not been shown effective in patients with malignant SFTs. PURPOSE: To describe a patient with a malignant SFT arising from the lumbar nerve root. STUDY DESIGN: A case report and review of literature. METHODS: We describe the clinical course of the patient and the radiological and pathological findings of the tumor. The effect of systemic chemotherapy was evaluated and the relevant literature was reviewed. This work has no disclosure of funding and was approved by the Institutional Review Board of Gifu University. RESULTS: The tumor had been resected previously at another hospital, but it recurred and showed multiple metastatic lesions on both lungs within 3 months. Although the patient received systemic chemotherapy, both primary and metastatic lesions were found to be stable disease according to Response Evaluation Criteria in Solid Tumors. The patient died due to cachexia 6 months after her first visit. CONCLUSION: This patient presented with a highly unusual tumor. Even if a tumor is a dumbbell-shaped mass, similar to a neural tumor, SFT should be considered in the differential diagnosis.

Secondary neurolymphomatosis detected by whole-body diffusion-weighted magnetic resonance imaging: a case report.

Neurolymphomatosis (NL) is a rare clinical entity defined as peripheral nervous system infiltration by lymphoma. The diagnosis is difficult and often elusive. Whole-body diffusion-weighted magnetic resonance imaging (DW MRI) was developed to enhance the detection of vaguely delineated tumors. Here, we describe the case of a 71-year-old male with secondary NL of diffuse large B-cell lymphoma (DLBCL) that was successfully detected by whole-body DW MRI. The patient was diagnosed with DLBCL extending from the ethmoidal sinus to the nasal cavity, orbital cavity, and anterior cranial fossa. Although he was administered R-THP-COP chemotherapy and the tumor remarkably decreased in size, he developed painful paresthesia and weakness in the left upper and bilateral lower extremities during treatment. Because lymphoma cells were detected in his spinal fluid, high-dose methotrexate (MTX) and weekly intrathecal MTX and cytarabine injections were administered. Test results for lymphoma cells in the spinal fluid became negative ; however, the neurological disorders progressed. Whole-body DW MRI was performed as whole-body screening and could localize NL at the left cervical and bilateral lumbar nerve roots. Both cervical spine plain MRI and enhanced computed tomography performed around the same time could not detect the cervical lesion. Our case report suggests that whole-body DW MRI is a useful diagnostic imaging procedure, especially as whole-body screening in facilities where PET/CT is not available.

Lipomatosis of the sciatic nerve secondary to compression by a desmoid tumor.

Lipomatosis of nerve is a rare benign tumor-like process characterized by infiltration of the epineurium by adipose and fibrous tissue leading to nerve enlargement. We describe a case of lipomatosis of the sciatic nerve compressed by an adjacent desmoid tumor. This case supports the hypothesis that lipomatosis of nerve may form as a result of irritation or compression by adjacent structures.

[Atypical clinical presentation of a neuroblastoma in an infant]. / Présentation clinique atypique d'un neuroblastome chez un nourrisson.

A babygirl, aged six weeks, was hospitalized for rectal prolapse and isolated constipation. The investigation revealed a neuroblastoma (NB) inducing a medullar compression responsible for the sphincter disorders. NB is second among pediatric solid tumors, but is the most frequent cancer among infants. Its diagnosis is difficult because of its rarity and the variety of its symptoms. A new staging, based on imaging, has recently been proposed by the International Neuroblastoma Risk Group. With the exception of its localized, easily resectable forms, NB is best treated by chemotherapy.