Successful Treatment with 177Lutetium-Dotatate and Maintenance Octreotide in a Patient with Esthesioneuroblastoma with Central Nervous System Invasion: Case Report and Review of the Literature

This article presents a case of a patient with relapsed esthesioneuroblastoma (ENB), an aggressive rare tumor that arises from the specialized sensory epithelial olfactory cells in the skull base area, which was initially treated with endoscopic surgery, followed by adjuvant radiotherapy. After local relapse, new surgical approaches and subsequent lines of platin-based chemotherapy were performed. A PET-CT with 68GALIUM DOTATATOC (PET-DOTATOC) showed intense uptake of disease, compatible with the presence of somatostatin receptors, in the face, nodes, liver, bones, and meningeal area. Treatment with 4 cycles of 177Lutetium-Dotatate was performed, followed by maintenance octreotide, with a major radiological and clinical response that is lasting more than 1 year after treatment. This article describes a rare case of a skull-base tumor, with multiple recurrences, in which disease control was achieved with a targeted Peptide Receptor Radionuclide Therapy (PRRT) with 177Lutetium-Dotatate, and discusses factors that could influence the incorporation of this form of therapy. Previous case reports proved the potential efficacy of this therapy usually given for low-grade neuroendocrine tumors and will be carefully reviewed.

Variant rs8400 enhances ALKBH5 expression through disrupting miR-186 binding and promotes neuroblastoma progression

Objective:AlkB homolog 5(ALKBH5)has been proven to be closely related to tumors.However,the role and molecular mechanism of ALKBH5 in neuroblastomas have rarely been reported.Methods:The potential functional single-nucleotide polymorphisms(SNPs)in ALKBH5 were identified by National Center for Biotechnology Information(NCBI)dbSNP screening and SNPinfo software.TaqMan probes were used for genotyping.A multiple logistic regression model was used to evaluate the effects of different SNP loci on the risk of neuroblastoma.The expression of ALKBH5 in neuroblastoma was evaluated by Western blotting and immunohistochemistry(IHC).Cell counting kit-8(CCK-8),plate colony formation and 5-ethynyl-2'-deoxyuridine(EdU)incorporation assays were used to evaluate cell proliferation.Wound healing and Transwell assays were used to compare cell migration and invasion.Thermodynamic modelling was performed to predict the ability of miRNAs to bind to ALKBH5 with the rs8400 G/A polymorphism.RNA sequencing,N6-methyladenosine(mA)sequencing,mA methylated RNA immunoprecipitation(MeRIP)and a luciferase assay were used to identify the targeting effect of ALKBH5 on SPP1.Results:ALKBH5 was highly expressed in neuroblastoma.Knocking down ALKBH5 inhibited the proliferation,migration and invasion of cancer cells.miR-186-3p negatively regulates the expression of ALKBH5,and this ability is affected by the rs8400 polymorphism.When the G nucleotide was mutated to A,the ability of miR-186-3p to bind to the 3'-UTR of ALKBH5 decreased,resulting in upregulation of ALKBH5.SPPI is the downstream target gene of the ALKBH5 oncogene.Knocking down SPP1 partially restored the inhibitory effect of ALKBH5 downregulation on neuroblastoma.Downregulation of ALKBH5 can improve the therapeutic efficacy of carboplatin and etoposide in neuroblastoma.Conclusions:We first found that the rs8400 G>A polymorphism in the m6A demethylase-encoding gene ALKBH5 increases neuroblastoma susceptibility and determines the related mechanisms.The aberrant regulation of ALKBH5 by miR-186-3p caused by this genetic variation in ALKBH5 promotes the occurrence and development of neuroblastoma through the ALKBH5-SPP1 axis.

Neural regeneration research model to be explored:SH-SY5Y human neuroblastoma cells

In neuroscience research,neuronal models are crucial tools for elucidating the molecular and cellular processes involved in the disorders of the nervous system.Facilitating easily and reproducibly executable studies,in vitro models,such as the SH-SY5Y cell line culture,help us explore the pathophysiological mechanisms of neurodegenerative diseases;they are also essential for the efficient screening of drugs for treating the diseases of the nervous system(Peng et al.,2021;Strother et al.,2021).

Nasal metastases from neuroblastoma-a rare entity:Two case reports

BACKGROUND Neuroblastoma(NB)is one of the most common malignancies in children.Metastasis in NB is not uncommon.However,nasal metastases are rare.Here,we reported two pediatric cases of nasal metastases.CASE SUMMARY Case 1 was a 3-year-old boy without a history of NB.Case 2 was a 10-year-old girl who had a history of NB for 6 years.Both of them presented with symptoms of nasal and sinus masses such as epistaxis or discharge from the nose.The radiologic imaging results revealed masses in the nasal cavity or nasopharynx in both cases and a mass in the right adrenal gland of case 1.The pathologic examination of biopsy samples of their nasal masses revealed“small round bluecell tumor”along with abundant vascular fibrous septa.The tumor cells expressed synaptophysin,cluster of differentiation 56,chromogranin A,paired like homeobox protein 2B and a very high Ki67 index in both case but were negative for vimentin,desmin,leucocyte common antigen and cytokeratin.Myelocytomatosis viral related oncogene,neuroblastoma derived(MYCN)amplification was detected in both cases.Finally,the two cases were diagnosed as nasal metastases from NB based on the clinical and pathologic findings.The two patients affected by NB were>18 mo old,the primary tumor location was adrenal gland,and they presented with multiple metastases.CONCLUSION It is difficult to differentiate between metastatic NB in the nose and olfactory neuroblastoma in the absence of a history of NB.Paired like homeobox protein 2B can play an important role in the diagnosis and differential diagnosis of this disease.

Treatment of Esthesioneuroblastoma and Nonsmall Cell Lung Cancer with Phenylbutyrate

Esthesioneuroblastoma is a malignant tumor, arising in the upper nasal cavity, that could spread to the frontal lobe of the brain as well as metastasize to the lymph nodes. Due to the low incidence of this tumor, FDA-approved treatment modalities do not exist and clinical trials have not been performed. We present an interesting case of a 66-year-old female, diagnosed with Kadish stage B esthesioneuroblastoma and stage IIA nonsmall cell carcinoma of the lung, who benefited from our treatment. Both malignancies were diagnosed in 2002 at which time the patient consented to undergo left upper lobectomy for her lung cancer, but she refused the craniofacial resection and radiation therapy recommended for treatment of her esthesioneuroblastoma. From 2003 to 2004 she received treatment at the Burzynski Clinic with oral sodium phenylbutyrate (0.2 g/kg/day). She tolerated the treatment very well without significant adverse events. Gradual reduction in her tumor size was confirmed by repeat MRIs. From treatment start in March 2003 to December 2003 her tumor decreased by 40%. Subsequent MRI from March 2004 revealed increased tumor size, which, however, was still a 13% reduction from the baseline MRI. What is important to mention is that in addition to shrinkage of the esthesioneuroblastoma, the patient obtained the clinical benefit of 3.5-years longer survival than was predicted for her lung cancer—whereas the median survival for a patient with stage IIA adenocarcinoma of the left upper lobe of the lung is approximately two years, our patient survived more than five and a half years. The effect of phenylbutyrate (PB) and its metabolite phenylacetate on neuroblastoma and lung cancer is documented by numerous preclinical studies and is also evident in this case. It is proposed that the activity of these two compounds is mediated through increased expression of the p21 tumor suppressor gene. p21 is a strong inhibitor of cyclin-D and cyclin-dependent kinase 4, which contribute to undifferentiated phenotype in neuroblastoma and are instrumental in cell cycle progression from G1 to S phase. It is hoped that future research and combination of PB with other chemotherapeutic and targeted agents will provide better control of esthesioneuroblastoma and lung cancer.

Esthesioneuroblastoma, Thyroid Gland Carcinoma and Gastrointestinal Stromal Carcinoma

Olfactory neuroblastoma (esthesioneuroblastoma, ЕNB) is a rare tumor arising from the olfactory neuroepithelium. We report a case of ЕNB located in inferior nasal concha, combined with thyroid gland carcinoma and gastrointestinal stromal carcinoma in a 77-year-old man. The tumor was resected endonasally. When the final diagnosis of olfactory neuroblastoma was confirmed by histopathologic examination and immunohistochemical staining, the PET/CT examination was performed. The imaging revealed a small focus of a moderately increased cancer activity in the thyroid region. A gastrointestinal stromal carcinoma was detected one year after the resection of the thyroid gland. We discuss the clinical appearance of ENB, staging systems, diagnosis and management. During the endonasal surgery, ENB was removed entirely. Seven days after operation, in order to monitor the postoperative result, PET/CT was performed and a papillary thyroid cancer was detected. One year after the thyroid surgery, gastroendoscopy showed a neoplastic formation in the stomach. In conclusion, we state that when identified as aggressive tumors such as ENB, it is necessary to provide regular examinations in order to detect distant ENB metastases or other neoplastic localisations.

Effect of combined treatment with cyclophosphamidum and allicin on neuroblastoma-bearing mice

Objective:To evaluate the efficacy of allicin combined with cyclophosphamide on neuroblastoma(NB)-bearing mice and explore the immunological mechanism in it.Methods:A total of 30NB-bearing mice were equally randomized into model group,cyclophosphamide group and combined therapy group,10 nudemice were set as normal saline(NS) group.Cyclophosphamide group and combined therapy group were weekly injected with 60 mg/kg cyclophosphamide for four weeks;besides,combined therapy group was given with allicin(10 mg/kg/d) by gastric perfusion for 4 weeks;model group and NS group were given with the same volume of NS.Serum VEGF content was detected by ELISA pre-treating(0 d) and on the 3rd d.14 th d and 28 th d;on29th d,all mice were sacrificed and the tumor,liver,spleen and thymic tissues were weighted.Tumors were made into paraffin section for detecting tumor cell apoptosis and proliferation by TUNEI.and BrdU method,respectively.Survival curves were drawn by Kaplan-Meier method.Results:After treatment,both treatment groups relieved on viscera indexes,VEGF level,T cell subsets distribution and tumor growth and each index of combined therapy group was better than cyclophosphamide group(P【0.05 or 0.01);only combined therapy group could significantly increase the lifetime of NB-bearing mice(χ~2=5.667,P=0.017).Conclusions:Allicin can improve T cell subsets distribution and inhibit VEGF expression through its immunomodulatory activity,thereby improve the efficiency on NB in coordination with cyclophosphamide.

Refractory diarrhea: A paraneoplastic syndrome of neuroblastoma

Neuroblastoma(NB) is the most common extracranial solid tumor in children. Diarrheal NB is quite rare and is not easy to diagnose in the early stage. Six cases of diarrheal NB in our hospital treated from 1996 to 2006 were retrospectively analyzed, including characteristics such as electrolyte imbalance, pathologic features, vasoactive intestinal peptide(VIP) immunohistochemical staining results, treatment, and prognosis. All patients were boys with 3-8 loose or watery stools each day and routine fecal tests were normal. Abdominal tumors were identified by B-ultrasound. Drugs were ineffective. Three patients underwent surgery, and the remaining three patients received surgery and chemotherapy. Diarrhea stopped after treatment in five patients. Two patients died due to intractable hypokalemia. The tumor was located in the adrenal gland in four patients, in the upper retroperitoneum in one patient, and in the presacral area in one patient. Pathologic findings were NB and ganglioneuroblastoma. Five patients were at clinical stage Ⅰ-Ⅱ, and one was at stage Ⅲ. Four patients survived(followed-up for 6 mo to 4 years). Immunohistochemical staining for VIP was positive. Refractory diarrhea is a paraneoplastic syndrome of NB and is rare. Patients aged 1-3 years who present with chronic intractable diarrhea should be followed closely. Intractable diarrhea, hypokalemia, and dysplasia are the initial clinical manifestations. Increased VIP is characteristic of this disease. Potassium supplementation plays a vital role in the treatment procedure, especially preoperatively. The prognosis of diarrheal NB is good following appropriate treatment.

Brain metastasis in children with stage 4 neuroblastoma after multidisciplinary treatment

Introduction: Brain metastasis is common in relapsed neuroblastoma patients, but the characteristics of brain metastasis remain largely unknown. This study aimed to investigate the status of brain metastasis with neuroblastoma in South China.Methods: In this retrospective case?based study, 106 patients with stage 4 neuroblastoma from the Department of Pediatric Oncology in Sun Yat?sen University Cancer Center between January 2004 and May 2013 were included. The incidence, risk factors, and survival status of these patients were reviewed and analyzed.Results: Of the 106 patients, 11(10.4%) developed brain metastasis, accounting for 20.0% of 55 patients with relapse or progression. The age at initial diagnosis of the 11 patients ranged from 2 to 10 years(median 4 years), which was younger than that of the patients without brain metastasis(median 5 years, range 1–10 years, P = 0.073). The male to female ratio of the 11 patients was 8:3, which was not signiicantly diferent from that of the patients with?out brain metastasis(P = 0.86). Patients with brain metastasis had higher lactate dehydrogenase levels than those without brain metastasis, but the diferences were not signiicant(P initial diagnosis to the develo= 0.076). Eight patients died, and 3 patients survived. The median interval from thepment of brain metastasis was 18 months(range 6–32 months). The median survival was 4 months(range 1 day to 29 months) after the diagnosis of brain metastasis. The median interval from the manifestation of brain metastasis to death was 3 months(range 1 day to 11 months).Conclusions: High?risk factors for brain metastasis in cases of neuroblastoma include bone marrow involvement and a younger age at initial diagnosis. Nevertheless, multiple treatment modalities can improve disease?free survival.

Chemokine receptor 4 gene silencing blocks neuroblastoma metastasis in vitro

This study investigated the effects of small interfering RNA （siRNA）-mediated silencing of chemokine receptor 4 （CXCR4） on the invasion capacity of human neuroblastoma cell line SH-SY5Y in vitro. Three siRNAs targeting CXCR4 were chemically synthesized and individually transfected into SH-SY5Y cells. Expression of CXCR4 mRNA and protein was signiifcantly sup-pressed in transfected cells by all three sequence-speciifc siRNAs compared with control groups. Furthermore, the invasion capacity of SH-SY5Y cells was signiifcantly decreased following trans-fection with CXCR4-speciifc siRNA compared with the control groups. These data demonstrate that down-regulation of CXCR4 can inhibit in vitro invasion of neuroblastoma.

COMBINATION OF γ-INTERFERON WITH TRAIL AND CISPLATIN OR ETOPOSIDE INDUCES APOPTOSIS IN HUMAN NEUROBLASTOMA CELL LINE SH-SY5Y

Objective To study the effect of γ-interferon （IFNγ）, tumor necrosis factor related apoptosis inducing ligand （TRAIL）, and cisplatin or etoposide induced apoptosis in human neuroblastoma cell line SH-SY5Y and its possible molecular mechanisms. Methods The expressions of Caspase 8 mRNA and protein were detected with RT-PCR and Western blot analysis. The effects of IFNγ, TRAIL, IFNγ ＋ TRAIL, IFNγ ＋ Caspase 8 inhibitor ＋ TRAIL, IFNγ ＋ cisplatin ＋ TRAIL, and IFNγ ＋ etoposide ＋ TRAIL on the growth and apoptosis of SH-SY5Y cells were detected with the methods of MTT and flow cytometry. The relative Caspase 8 activity was measured with colorimetric assay. Results Caspase 8 was undetectable in SH-SY5Y cells but an increased expression of Caspase 8 mRNA and protein was found after treatment with IFNγ. SH-SY5Y ceils themselves were not sensitive to TRAIL, but those expressing Caspase 8 after treatment with IFNγ were. The killing effect of TRAIL on SH-SY5Y cells expressing Caspase 8 was depressed by Caspase 8 inhibitor. Cisplatin and etoposide could enhance the sensitivity of TRAIL on SH-SY5Y cells. The relative Caspase 8 activity of SH-SY5Y cells in IFNγ ＋ TRAIL group was significantly higher than those of control group, IFNγ group, TRAIL group, and inhibitor group （ P 〈 0. 01 ）. There was no significant difference among IFNγ ＋ TRAIL group, IFNγ ＋ cisplatin ＋ TRAIL group, and IFNγ ＋ etoposide ＋ TRAIL group. Conclusions IFNγ could sensitize SH-SY5Y cells to TRAIL-induced apoptosis and this may be realized by the up-regulation of Caspase 8. Cisplatin and etoposide could enhance the killing effect of TRAIL on SH-SY5Y cells.

FHL2 Interacts with and Acts as a Functional Repressor of Id2 in Human Neuroblastoma Cells

Objective： Id2 is a natural inhibitor of the basic helix-loop-helix（bHLH） transcription factors. Although it is well known that active ld2 prevents differentiation and promotes cell cycle progression and tumorigenesis, the molecular events that regulate Id2 activity remain to be investigated. Methods： Yeast two-hybrid, mammalian two-hybrid, GST-pulldown and immunoprecipitation （ColP） assays were used to screen and identify novel Id2 interactors. Luciferase assays were used to detect E47-mediated transcription activity. Colony formation and BrdU incorporation assays were used to determine cellular proliferation abilities. Northorn blot, western blot and quantitative PCR methods were used to measure gene expression levels. Electrophoretic mobility shift assays （EMSAs） were performed to investigate protein/DNA binding. Results： The LIM-only protein FHL2 （four-and-a-half-LIM-only protein 2） was identified to be a novel Id2 interactor. The HLH domain within Id2 is not required for its interaction with FHL2. FHL2 antagonizes the inhibitory effect of Id2 on the basic helix-loop-helix protein E47-mediated transcription. FHL2 prevents the formation of Id2-E47 heterdimer, thus releasing E47 to its target DNA and restoring its transcriptional activity. FHL2 expression was remarkably up-regulated during retinoic acid-induced differentiation of neuroblastoma cells, during which the expression of Id2 is opposite to that. Ectopic FHL2 expression in neuroblastoma cells markedly reduces the transcriptional and cell-cycle promoting functions of Id2. Conclusion： These results indicate that FHL2 is an important repressor of the oncogenic activity of Id2 in neuroblastoma cells.

Combination therapies improve the anticancer activities of retinoids in neuroblastoma

Most therapeutic protocols for child cancers use cytotoxic agents which have a narrow therapeutic index,and resulting in severe acute and chronic toxicities to normal tissues. Despite the fact that most child cancer patients achieve complete remission after chemotherapy,death still occurs due to relapse of persistent minimal residual disease(MRD) which remaining after initial cytotoxic chemotherapy. Advanced neuroblastoma(NB) is a leading cause of cancer deaths in young children. Retinoids are an important component of advanced NB therapy at the stage of MRD,yet half of all patients treated with 13-cis-retinoic acid still relapse and die. More effective combination therapies,with a lower side-effect profile,are required to improve outcomes for NB. Fenretinide or N-4-hydroxyphenyl retinamide is a synthetic derivative of retinoic acid which works on cancer cells through nuclear receptor-dependent and-independent signalling mechanisms. Moreover,several histone deacetylase inhibitors have entered early phase trials,and,suberoylanilide hydroxamic acid has been approved for use in adult cutaneous T cell lymphoma. A number of studies suggest that retinoid signal activation is necessary for histone deacetylase inhibitor activity. A better understanding of their mechanism of actions will lead to more evidence-based retinoid combination therapies.

Protective effects of ginsenoside Rg1 against hydrogen peroxide-induced injury in human neuroblastoma cells

The active ingredient of ginseng,ginsenosides Rg1,has been shown to scavenge free radicals and improve antioxidant capacity.This study hypothesized that ginsenosides Rg1 has a protective role in human neuroblastoma cells injured by H2O2.Ginsenosides Rg1 at different concentrations（50 and 100 μM） was used to treat H2O2（150 μM）-injured SH-SY5 Y cells.Results demonstrated that ginsenoside Rg1 elevated the survival rate of SH-SY5 Y cells injured by H2O2,diminished the amount of leaked lactate dehydrogenase,and increased superoxide dismutase activity.Ginsenoside Rg1 effectively suppressed caspase-3 immunoreactivity,and contributed to heat shock protein 70 gene expression,in a dose-dependent manner.These results indicate that ginsenoside Rg1 has protective effects on SH-SY5 Y cells injured by H2O2 and that its mechanism of action is associated with anti-oxidation and the inhibition of apoptosis.

Induction of Mitochondrial Pathways and Endoplasmic Reticulum Stress for Increasing Apoptosis in Ectopic and Orthotopic Neuroblastoma Xenografts

Cancers are characterized by deregulation of multiple signaling pathways and thus monotherapies are hardly effective. Neuroblastoma, which often occurs in adrenal glands, is the most common childhood malignancy. Malignant neuroblastoma resists traditional treatments and further studies are needed for effective therapeutic interventions. We evaluated synergistic efficacy of N-(4-hydroxyphenyl) retinamide (4-HPR) and genistein (GST) for induction of apoptosis in human malignant neuroblastoma SH-SY5Y and SK-N-BE2 cells in culture and activation of multiple pathways for increasing apoptosis in ectopic and orthotopic neuroblastoma xenografts in nude mice. Combination of 4-HPR and GST synergistically reduced cell viability, caused subG1 accumulation, increased caspase-3 activity for apoptosis in vitro and reduced tumor growth in vivo. Western blotting indicated that combination therapy down regulated Id2 to induce differentiation, increased pro-apoptotic Bax and decreased anti-apoptotic Bcl-2 leading to an increase in Bax:Bcl-2 ratio, increased mitochondrial Bax level, caused mitochondrial release of Smac/Diablo, down regulation of the baculovirus inhibitor-of-apoptosis repeat containing (BIRC) proteins such as BIRC-2 and BIRC-3, and activation of calpain and caspase-3 in SH-SY5Y xenografts. Accumulation of apoptosis-inducing-factor (AIF) in cytosol and increase in caspase-4 activation suggested involvement of mitochondrial pathway and endoplasmic reticulum (ER) stress, respectively, for apoptosis in SH-SY5Y xenografts. In situ immunofluorescent labelings of SH-SY5Y and SK-N-BE2 xenograft sections showed overexpression of calpain, caspase-12, and caspase-3, and AIF, suggesting induction of mitochondrial caspase-dependent and caspase-independent pathways for apoptosis. Collectively, synergistic effects of 4-HPR and GST induced mitochondrial pathways and also ER stress for increasing apoptosis in ectopic and orthotopic neuroblastoma xenografts in nude mice.

Down-regulation of Tissue Factor by siRNA Increased Doxorubi-cin-induced Apoptosis in Human Neuroblastoma

The effects of tissue factor （TF） on doxorubicin-induced apoptosis in human neuroblastoma were investigated. The expression of TF was examined by Western blotting. TFsiRNA-pSUPER plasmid was constructed by inserting specific 19-nt silencing sequence targeting TF gene into pSUPER vector. Transfection of TFsiRNA-pSUPER was performed using lipofectamine^2000. The cytotoxicity of doxorubicin was determined by WST assay. The activation of Caspase-3 and PARP induced by doxorubicin was tested by Western blotting. The apoptotic cells were stained by Hochest33342 and counted under fluorescence inverted microscope. It was found that human neuroblastoma cell line SK-N-MC expressed high level of TE Knockdown of the TF expression was achieved by transfection of TFsiRNA-pSUPER on SK-N-MC cells in a dose-dependent manner. Inhibition of TF significantly decreased the viability of transfected SK-N-MC cells treated with different concentrations of doxorubicin. Cleavage of Caspase-3 and PARP was enhanced in transfected SK-N-MC cells with down-regulation of TF. TFsiRNA treatment significantly increased the number of apoptotic cells in transfected SK-N-MC cells as compared with those control cells （P〈0.05） when these cells were exposed to 1 μg/mL doxorubicin for 8 h. These results suggested that knockdown of the TF expression by specific siRNA vector could increase the cytotoxicity of doxorubicin and enhance doxorubicin-induced apoptosis in human neuroblastoma cells. Over-expression of TF might contribute to chemotherapy resistance in human neuroblastoma and its progression, at lest in part, by regulating doxorubicin-induced apoptosis.

Management of neuroblastoma in limited-resource settings

BACKGROUND Neuroblastoma(NB)is a heterogeneous disease with variable outcomes among countries.Little is known about NB in low-and middle-income countries(LMICs).AIM The aim of this review was to evaluate regional management protocols and challenges in treating NB in paediatric oncology units in LMICs compared to high-income countries(HICs).METHODS PubMed,Global Health,Embase,SciELO,African Index Medicus and Google Scholar were searched for publications with keywords pertaining to NB,LMICs and outcomes.Only English language manuscripts and abstracts were included.A descriptive review was done,and tables illustrating the findings were constructed.RESULTS Limited information beyond single-institution experiences regarding NB outcomes in LMICs was available.The disease characteristics varied among countries for the following variables:sex,age at presentation,MYCN amplification,stage and outcome.LMICs were found to be burdened with a higher percentage of stage 4 and high-risk NB compared to HICs.Implementation of evidence-based treatment protocols was still a barrier to care.Many socioeconomic variables also influenced the diagnosis,management and followup of patients with NB.CONCLUSION Patients presented at a later age with more advanced disease in LMICs.Management was limited by the lack of resources and genetic studies for improved NB classification.Further research is needed to develop modified diagnostic and treatment protocols for LMICs in the face of limited resources.

Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting

Pediatric neuroblastomas(NBs)are heterogeneous,aggressive,therapy-resistant embryonal tumours that originate from cells of neural crest(NC)origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage.Therapeutic resistance,post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell(CSC)-like subpopulations,which through their self-renewing capacity,intermittent and slow cell cycles,drug-resistant and reversibly adaptive plastic phenotypes,represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs.In this review,dedicated to NB CSCs and the prospects for their therapeutic eradication,we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction,specification,epithelial to mesenchymal transition and migratory behaviour,in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB.We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs,before providing a comprehensive review of the salient molecules,signalling pathways,mechanisms,tumour microenvironmental and therapeutic conditions involved in promoting,selecting and maintaining NB CSC subpopulations,and that underpin their therapy-resistant,self-renewing metastatic behaviour.Finally,we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance,post-therapeutic relapse and metastatic progression.

FLUORESCENCE IN SITU HYBRIDIZATION COMBINED WITH IMMUNOFLUORESCENT STAINING FOR RAPID DETECTION OF Nmyc AMPLIFICATION IN NEUROBLASTOMA

Objective: To establish a method to improve the detection of disseminated tumor cells in bone marrow and peripheral blood samples of neuroblastoma patients and analysis of cytogenetic aberration. Methods: Immunofluorescent staining was performed using a cocktail of primary monoclonal neuroblastoma antibodies (14.G2a, 5.1H11). Fluorescence in situ hybridization was applied with fluorescent probes specific for Nmyc genes afterwards. A novel computer assisted scanning system for automatic search, image analysis and repositioning of these positive cells was developed. Fifty-six bone marrow and peripheral blood samples from 7 patients were evaluated by this method. Results: Fluorescence in situ hybridization can be combined with immunofluorescent staining in detecting Nmyc amplification in neuroblastoma patients. Fluorescence in situ hybridization results correlated well with data obtained by conventional cytogenetic procedures. Conclusion: The technique described allows search of tumor cells in the bone marrow as well as detection of Nmyc amplification in interphase nuclei.

Antitumor Activity of Erythromycin on Human Neuroblastoma Cell Line(SH-SY5Y)

Antitumor effects of erythromycin and the related mechanism were investigated in the present study.Neuroblastoma cells（SH-SY5Y） were exposed to erythromycin at different concentrations for different durations.Cell proliferation was measured by cell counting,and cell viability was examined by MTT assay.Cell cycle phase distribution and the cytosolic calcium level were detected by flow cytometry.Mitochondrial membrane potential was measured by the JC-1 probe staining and fluorescent microscopy.The expression of an oncogene（c-Myc） and a tumor suppressor [p21（WAF1/Cip1）] proteins was analyzed by using Western blotting.Erythromycin could inhibit the proliferation of SH-SY5Y cells in a concentration-and time-dependent manner.The cell cycle was arrested at S phase.Mitochondrial membrane potential collapsed and the cytosolic calcium was overloaded in SH-SY5Y cells when treated with erythromycin.The expression of c-Myc protein was down-regulated,while that of p21（WAF1/Cip1） protein was up-regulated.It was concluded that erythromycin could restrain the proliferation of SH-SY5Y cells.The antitumor mechanism of erythromycin might involve regulating the expression of c-Myc and p21（WAF1/Cip1） proteins.