Work

Regulation of MDMX Expression by Mitogenic Signaling

Year: 2008

Type: article

Abstract: MDMX is an important regulator of p53 transcriptional activity and stress response. MDMX overexpression and gene amplification are implicated in p53 inactivation and tumor development. Unlike MDM2, MDMX is not inducible by p53, and little is known about its regulation at the transcriptional level. We found that MDMX levels in tumor cell lines closely correlate with promoter activity and mRNA level. Activated K-Ras and insulin-like growth factor 1 induce MDMX expression at the transcriptional level through mechanisms that involve the mitogen-activated protein kinase and c-Ets-1 transcription factors. Pharmacological inhibition of MEK results in down-regulation of MDMX in tumor cell lines. MDMX overexpression was detected in approximately 50% of human colon tumors and showed strong correlation with increased extracellular signal-regulated kinase phosphorylation. Therefore, MDMX expression is regulated by mitogenic signaling pathways. This mechanism may protect normal proliferating cells from p53 but also hamper p53 response during tumor development.

Source: Molecular and Cellular Biology

DOI: 10.1128/mcb.01633-07

Authors: Daniele M. Gilkes, Yu Pan, Domenico Coppola, Timothy Yeatman, Gary W. Reuther, Jiandong Chen

Institution: Moffitt Cancer Center

Language: English

Topic: Cancer-related Molecular Pathways

Subfield: Oncology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: University of South Florida, National Institutes of Health, National Cancer Institute