Track topics on Twitter Track topics that are important to you
Neuroblastoma (NB) is the most common malignant tumor of infancy. Approximately 60% of NB patients are clinically diagnosed as the stage IV disease and have a very poor prognosis with the 5-year survival rate no more than 30%. Molecular markers of NB have great impacts on the tumor behavior. MYCN amplification is the most well-known marker to predict a poor outcome in NB patients. However, how MYCN affects the NB cell behavior remains unknown. In our preliminary studies, we performed a genome-wide analysis of the differential gene expression in 10 NB tumors with MYCN amplification and 10 with normal MYCN copy number. We found that aromatic hydrocarbon receptor (AHR) reversely correlated with the MYCN expression. This relationship was verified in 83 NB tumor samples. In addition, positive AHR expression by immunostaining of NB tumors predicted a favorable prognosis. These lines of evidence demonstrate that AHR not only relates to the MYCN expression but also plays an important role in the tumorigenesis of NB. Therefore in this project we aim at further studying the relationship between AHR and MYCN. In addition, the possible role of AHR in the tumorigenesis of NB will be clarified. Specifically, we propose a 3-year project with the following three aims:
Aim I. Determine the molecular relationship between AHR and MYCN expression. AHR has been shown to suppress the E2F1 expression. E2F1 reversely has been found to upregulate the expression of MYCN. In our preliminary microarray study, we also found that the expression E2F1 positively correlated with the MYCN expression but inversely correlated with the expression of AHR. Therefore, NB cells will be transfected with AHR expression vector or AHR siRNA, then the associated E2F1 and MYCN expression will be examined to clarify if AHR could regulate MYCN expression via E2F1. Furthermore, the E2F1 levels will also be manipulated to determine if the effect of AHR on MYCN depends on E2F1. In addition, the E2F1 expression in NB tumor samples will also be examined to clarify its in vivo role.
Aim II. Determine the effect of AHR expression on the NB cell behavior. The baseline AHR expression levels in several NB cell lines will be examined. AHR is then overexpressed by gene transfection in NB cells. The cell proliferation, migration, and differentiation after AHR overexpression are evaluated. Furthermore the AHR expression in normal neuron cells is also examined, and suppressed by siRNA to if downregulation of AHR could lead to cancer development.
Aim III. Determine if AHR could be a target of gene therapy for NB. NB cells with either normal MYCN or MYCN amplification before and after AHR gene transfection are inoculated into nude mice to demonstrate the effect of AHR expression on NB cells behavior in vivo. AHR is then transfected into the wild type NB tumor to see if the tumor growth could be suppressed by AHR expression. Then wild type tumor and tumors transfected with AHR are subjected microarray analysis to compare with the human tumor data set for evaluation of gene expression changes along with differential AHR expression. Altogether, our studies will not only establish the relationship between AHR and MYCN, but also allow us to depict the functional role of AHR-MYCN interaction in the tumorigenesis of NB.
Observational Model: Cohort, Time Perspective: Retrospective
National Taiwan University Hospital
Published on BioPortfolio: 2014-08-27T03:15:41-0400
Medical scientists want to find better ways to treat neuroblastoma and to find ways to prevent the tumor from growing back. To do this, they need more information about the characteristics...
RATIONALE: Studying the genes in a child's cancer cells may help doctors improve ways to diagnose and treat children with neuroblastoma. PURPOSE: This clinical trial is studying the genes...
RATIONALE: Surgery may be an effective treatment for neuroblastoma. PURPOSE: This phase II trial is studying how well surgery works in treating patients with neuroblastoma.
Patients with refractory and/or recurrent neuroblastoma have poor prognosis despite complex multimodel therapy and therefore, novel approaches are urgently needed. The investigators are at...
Difluoromethylornithine (DFMO) will be used in an open label, single agent, multicenter, study for patients with neuroblastoma in remission. In this study subjects will receive 730 Days of...
Neuroblastoma (NB) is the most common extracranial solid tumor of childhood. Primary and secondary testicular involvement is extremely uncommon in neuroblastoma.
Neuroblastoma is a lethal tumor that commonly occurs in children. Polymorphisms in reportedly influence risk for several types of cancer, though their roles in neuroblastoma remain unclear. Here we e...
Neuroblastoma is the commonest malignancy in neonates. Long non-coding RNA (lncRNA) RNA component of mitochondrial RNA processing endoribonuclease (RMRP) has been reported to be an oncogenic factor in...
Neuroblastoma is a neural crest-derived tumor that accounts for 7-10% of all malignancies in children and ~15% of all childhood cancer-associated mortalities. Approximately 50% of patients are charact...
Neuroblastoma is one of the most common paediatric malignancies. Detection of somatic genetic alterations in this tumour is instrumental for its risk stratification and treatment. On the other hand, a...
An indolocarbazole that is a potent PROTEIN KINASE C inhibitor which enhances cAMP-mediated responses in human neuroblastoma cells. (Biochem Biophys Res Commun 1995;214(3):1114-20)
A malignant olfactory neuroblastoma arising from the olfactory epithelium of the superior nasal cavity and cribriform plate. It is uncommon (3% of nasal tumors) and rarely is associated with the production of excess hormones (e.g., SIADH, Cushing Syndrome). It has a high propensity for multiple local recurrences and bony metastases. (From Holland et al., Cancer Medicine, 3rd ed, p1245; J Laryngol Otol 1998 Jul;112(7):628-33)
A moderately malignant neoplasm composed of primitive neuroectodermal cells dispersed in myxomatous or fibrous stroma intermixed with mature ganglion cells. It may undergo transformation into a neuroblastoma. It arises from the sympathetic trunk or less frequently from the adrenal medulla, cerebral cortex, and other locations. Cervical ganglioneuroblastomas may be associated with HORNER SYNDROME and the tumor may occasionally secrete vasoactive intestinal peptide, resulting in chronic diarrhea.
Genes of IAP elements (a family of retrovirus-like genetic elements) which code for virus-like particles (IAPs) found regularly in rodent early embryos. ("Intracisternal" refers to the cisternae of the endoplasmic reticulum.) Under certain circumstances, such as DNA hypomethylation they are transcribed. Their transcripts are found in a variety of neoplasms, including plasmacytomas, neuroblastoma, rhabdomyosarcomas, teratocarcinomas, and colon carcinomas.
Family of retrovirus-associated DNA sequences (ras) originally isolated from Harvey (H-ras, Ha-ras, rasH) and Kirsten (K-ras, Ki-ras, rasK) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both H-ras and K-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related N-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein.
Bioinformatics is the application of computer software and hardware to the management of biological data to create useful information. Computers are used to gather, store, analyze and integrate biological and genetic information which can then be applied...