MBP-1 reprime l’espressione di N-MYC e svolge il ruolo di oncosoppressore in cellule di Neuroblastoma umano LAN5

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Abstract

[automatically translated] Neuroblastoma, derived from primitive neural sympathetic cells, is the most common childhood extracranial solid tumor. Amplification of N-MYC gene with deletions in chromosome 1p36, are the most frequent molecular markers in Neuroblastoma and are associated with poor prognosis. MBP-1, alternative product of mRNA translation of ENO1 gene is a transcriptional repressor and acts directly on the promoter of the c-MYC genes, ERBB2 and COX2 (1-3). In Neuroblastoma cells has been observed that the ectopic expression of ENO1 / MBP-1 causes induction of apoptosis and cell death (4). Although there is similarity of structure and function among the N-MYC and c-MYC gene it is not known whether the MBP-1 is able to repress transcription also the N-MYC gene. To investigate this possibility, a series of reporter plasmids (luciferase), containing various portions of the promoter of N-MYC, was used in transfection experiments in Neuroblastoma cells with N-MYC amplified (LAN-5) together with an expression vector for MBP-1 . These studies have identified a region of the promoter responsible for the negative regulation of N-MYC by MBP-1. The direct binding activity was confirmed by studies conducted by EMSA experiments and chromatin immunoprecipitation (ChIP). The use of a SiRNA-mediated induction system of the expression of endogenous MBP-1 in LAN-5 cells has allowed us to study the effect of MBP-1 in neuroblastoma cells. The induction of the MBP-1 is, as expected, in the reduction of ' expression of N-MYC and in a significant increase in the expression of proteins Bax, p21 and γ-enolase (a neuronal differentiation marker). Essays on migration and cellular cytotoxicity have also allowed to establish that MBP-1 induces apoptosis and reduces the migration of LAN-5 cells. In conclusion, the data indicate that MBP-1 acts as a transcriptional repressor of N-MYC gene, and its expression in human neuroblastoma cells induces differentiation and apoptosis and inhibition of cell migration. References 1. Feo S, D Arcuri, piddini And, Passantino R, A. Giallongo ENO1 gene products binds to the c-myc gene promoter and acts as a transcriptional repressor: relationship with MBP-1. FEBS Lett. 2000, 473: 47 2. Contino F., C. Mazzarella, Iron A, et al. Negative Transcriptional control of the ERBB2 gene by MBP-1 and HDAC1: diagnostic implication in breast cancer. BMC Cancer 2013.13: 8 KW 3. Hsu, RH Hsieh, Wu CW, Who CW et al. MBP-1 suppresses growth and metastasis in gastric cancer cells through COX-2. Mol Biol. 2009 20: 5127. 4. Eiskar K, Krona C, Caren H, et al. Introduction of in vitro transcribed mRNA ENO1 into neuroblastoma cells induces cell death. BMC Cancer 2005.5: 161.
Original languageItalian
Number of pages58
Publication statusPublished - 2013

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