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BACKGROUND: Neurotrophin-3 (NT-3), a member of the NT family, has only been considered an ancillary compound that provides anti-apoptotic benefits by inactivating tropomyosin receptor kinase C (TrkC)-induced apoptotic signals. However, little is known about the clinical relevance of NT-3 expression itself in neuroblastoma. The purpose of this study was to assess NT-3 expression in patients with neuroblastoma and its relevance to clinicopathologic findings and treatment outcomes. METHODS: In this study, expression of NT-3 and TrkC was analyzed using immunohistochemistry in 240 patients with newly diagnosed neuroblastoma. RESULTS: The results of the study revealed that NT-3 expression was associated with older age at diagnosis, localized tumors, and more differentiated tumors but was not associated with early treatment response (degree of residual tumor volume after three cycles of chemotherapy) and progression-free survival (PFS). However, when analysis was confined to patients with MYCN amplified tumors, NT-3 expression was associated with better early treatment response with borderline significance (P = 0.092) and higher PFS (86.9% vs. 58.2%; P = 0.044). In multivariate analysis in patients with MYCN amplified tumors, NT-3 was independent prognostic factor (hazard ratio, 0.246; 95% confidence interval, 0.061–0.997; P = 0.050). In another subgroup analysis, the early treatment response was better if NT-3 was expressed in patients without TrkC expression (P = 0.053) while it was poorer in patients with TrkC expression (P = 0.023). CONCLUSION: This study suggests that NT-3 expression in neuroblastoma has its own clinical significance independent of TrkC expression, and its prognostic significance differs depending on the status of MYCN amplification and/or TrkC expression.
Subject(s)
Humans , Diagnosis , Disease-Free Survival , Immunohistochemistry , Multivariate Analysis , Neoplasm, Residual , Neuroblastoma , Phosphotransferases , TropomyosinABSTRACT
Introduction: Medulloblastoma is a malignant embryonal tumor of the cerebellum with poor prognosis. The treatment is based only on clinical criteria, such as risk group that only considers age, extent of tumor resection, recurrence, and metastasis. Objective: To evaluate a possible relationship between the immunoexpression of biomarkers (Ki67, receptor neutrophin-3 [TRKC], epidermal growth factor receptor [EGFR], B-cell lymphoma 2 [Bcl-2], and cyclin-D1), and the classical clinical prognostic factors of medulloblastoma. Material and method: thirty-five samples of pediatric medulloblastoma free of neoadjuvant chemotherapy were separated and reviewed for their histopathological classification; two areas representative of tumor were used in the construction of tissue microarrays. The following clinical data from 29 patients were used for comparison with the biomarkers expression: patient's age, presence or absence of complete tumor resection, staging patient's risk group, presence or absence of metastases, presence or absence of postoperative chemotherapy, and presence or absence of recurrence. Clinical follow-up of the study ranged from two to thirteen years, and cases with fatal outcome were also analyzed. Results: Patients with upper age showed higher expression of TRKC (p = 0.033). There was inversely proportional and statistically significant correlation between TRKC and Ki67 (p = 0.027). There was no statistical significance in the analysis of EGFR, Bcl2, and cyclin-D1. Conclusion: The immunoexpression of TRKC might be considered a biomarker related to tumors with better prognosis in patients with medulloblastoma, contributing to better risk groups' stratification...
Introdução: O meduloblastoma é o tumor maligno do cerebelo com prognóstico reservado. Seu tratamento baseia-se somente em critérios clínicos, como os grupos de risco que levam em consideração apenas idade, extensão de ressecção, recidiva e metástase. Objetivo: Avaliar uma possível relação entre a imunoexpressão de biomarcadores (Ki67, receptor de neurotrofina-3 [TRKC], epidermal growth factor receptor [EGFR], B-cell lymphoma 2 [Bcl-2] e ciclina-D1) e os fatores prognósticos clínicos clássicos dos meduloblastomas. Material e método: Trinta e cinco amostras de meduloblastomas pediátricos livres de tratamento quimioterápico neoadjuvante foram separadas e revisadas quanto a sua classificação histopatológica, sendo duas áreas representativas do tumor utilizadas na construção de arranjos teciduais em matriz. Os seguintes dados clínicos de 29 pacientes foram utilizados para comparação com a expressão dos biomarcadores: idade do paciente, presença ou não de ressecção tumoral completa, estadiamento do paciente em grupo de risco, presença ou não de metástases, presença ou não de tratamento quimioterápico pós-cirúrgico e presença ou não de recidivas. O tempo de seguimento clínico do estudo variou de dois a treze anos, e os casos com desfecho fatal foram também analisados. Resultados: Os pacientes com idade mais elevada apresentaram expressão maior de TRKC (p = 0,033). Houve correlação inversamente proporcional e estatisticamente significativa entre o TRKC e o Ki67 (p = 0,027). Não houve relevância estatística nas análises do EGFR, Bcl-2 e ciclina-D1. Conclusão: A imunoexpressão do TRKC pode vir a ser considerada um biomarcador relacionado com tumores de melhor prognóstico em pacientes com meduloblastoma, contribuindo para uma melhor estratificação dos grupos de risco...
Subject(s)
Humans , Child , Immunohistochemistry , Medulloblastoma , Biomarkers, Tumor , PrognosisABSTRACT
Objective To detect the expression and the biological activity of a recombinant adenovirus expression vector carrying human neurotrophin-3 (NT-3) receptor TrkC gene (Adeno-TrkC) in neural stem cells. Methods The expression of TrkC mRNA in 293 cells infected with Adeno-TrkC was detected by RT-PCR, and the expression of TrkC protein in neural stem cells infected by Adeno-TrkC was detected with immunocytochemistry and Western blotting. The effects of human neurotrophin_3 (NT-3) on the neural stem cells infected by Adeno-TrkC differentiating into neuron-like cells and astrocyte-like cells in vitro were observed. Results The transcription of TrkC mRNA and the expression of TrkC protein was detected in 293 cells and neural stem cells infected by Adeno-TrkC. This kind of TrkC was able to make more neural stem cells differenting into neuron-like cells in vitro with its ligand NT-3 and the percentage of neuron-like cell’s differentiation was 55
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Objective To investigate the effects of high-affinity tyrosine kinase receptors TrkA, TrkC and the low-affinity neurotrophin receptor p75 (p75~ NTR) protein in laser-induced retinal injury. Methods The Wistar rats were anesthetized and exposed to frequency doubling Neodymium:Yttrium,aluminum garnet(ND:YAG,?=532nm) laser for 100 plus per eye, which were sacrificed on 12 hours,1,3,7,14 and 28 days after laser exposure and eyeball was taken out. We investigated retinal histology by hematoxylin and eosin staining, and the expression of TrkA, TrkC and p75~ NTR protein was studied by means of immunohistochemistry. Results Immunohistochemistry results showed a differential distribution for these three neurotrophin receptors in the laser injuried retina. TrkA was enhanced in nerve fiber layer (NFL), ganglion cell layer(GCL) and inner nuclear layer(INL) ,which is the most nuclei of the ganglion cells, proximal M?ller cell end feet and a little cells in the innermost part of the INL, its peak of up-regulation was after day 1-3, after day 28 there was sustained. Whereas TrkC and p75~ NTR expression was enhanced in the outer nuclear layer(ONL), which is distal M?ller cell processes, TrkC up-regulated after 12 hours, its peak was on day 1-3, after day 28 there was sustained, p75~ NTR up-regulated after 24 hours, its peak was on day 3, on day 14-28 there was sustained in the GCL, which is proximal M?ller cell processes. Conclusion The expression of TrkA, TrkC and p75~ NTR participated in the course of laser injuried retinal pathology.