p53 Is a Direct Transcriptional Target of MYCN in Neuroblastoma.

p53 Is a Direct Transcriptional Target of MYCN in Neuroblastoma.

Cancer Res. 2010 Feb 9;

Authors: Chen L, Iraci N, Gherardi S, Gamble LD, Wood KM, Perini G, Lunec J, Tweddle DA

MYCN amplification occurs in approximately 25% of neuroblastomas, where it is associated with rapid tumor progression and poor prognosis. MYCN plays a paradoxical role in driving cellular proliferation and inducing apoptosis. Based on observations of nuclear p53 accumulation in neuroblastoma, we hypothesized that MYCN may regulate p53 in this setting. Immunohistochemical analysis of 82 neuroblastoma tumors showed an association of high p53 expression with MYCN expression and amplification. In a panel of 5 MYCN-amplified and 5 nonamplified neuroblastoma cell lines, and also in the Tet21N-regulatable MYCN expression system, we further documented a correlation between the expression of MYCN and p53. In MYCN-amplified neuroblastoma cell lines, MYCN knockdown decreased p53 expression. In Tet21N MYCN+ cells, higher levels of p53 transcription, mRNA, and protein were observed relative to Tet21N MYCN- cells. In chromatin immunoprecipitation and reporter gene assays, MYCN bound directly to a Myc E-Box DNA binding motif located close to the transcriptional start site within the p53 promoter, where it could initiate transcription. E-Box mutation decreased MYCN-driven transcriptional activation. Microarray analysis of Tet21N MYCN+/- cells identified several p53-regulated genes that were upregulated in the presence of MYCN, including MDM2 and PUMA, the levels of which were reduced by MYCN knockdown. We concluded that MYCN transcriptionally upregulates p53 in neuroblastoma and uses p53 to mediate a key mechanism of apoptosis. Cancer Res; 70(4); 1377-88.

PMID: 20145147 [PubMed - as supplied by publisher]

Read the complete post at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=20145147&dopt=Abstract

Posted 11 Feb 2010 4:53 AM by pubmed: neuroblastoma
Filed under:

Seten amet diorl oprta ahsellu miokiste porta.

Bean nonumy hendrit mauris phelus porta. Fusce suscipit varius ui. Fusce feugiat malesada odio. Morbi nunc odio, gravida sit cursusnec, luctus aorem. auris phelus porta ae. Fusce suscipit varius ui. Fusce feug.

Read More

There is nothing quite as devastating as hearing that word - neuroblastoma. In seconds your world is turned upside down and your normal life is but a distant memory. You are thrust into a confusing world full of fear. Your child has cancer.

We know. We have been there. The Neuroblastoma Foundation is here for you.

Welcome to our website. It is a place for you to find answers and ask questions. One of the primary goals of the Neuroblastoma Foundation is to ensure that parents, patients and health care professionals find the information they need to make the best treatment decisions possible for children and adults affected by neuroblastoma. There is a vast amount of information throughout the internet, much of which is encapsulated in medical jargon that is so complex that even many medical professionals have difficulty in interpreting its meaning. We are here to help to decipher this information and to make sure you (and your oncologist) understand exactly what it means to you. From treatment decisions to side effects we have parents and experts that have experienced it all and are willing to distill it for you.