Abstract
MCT-1 oncoprotein accelerates p53 degradation by means of the ubiquitin-dependent proteolysis. Our present data show that induction of MCT-1 increases chromosomal translocations and deregulated G 2-M checkpoint in response to chemotherapeutic genotoxin. Remarkably, increases in chromosome copy number, multinucleation, and cytokinesis failure are also promoted while MCT-1 is induced in p53-deficient cells. In such a circumstance, the Ras-mitogen-activated protein kinase/extracellular signal-regulated kinase kinase-mitogen-activated protein kinase signaling activity and the expression of metastatic molecules are amplified. Given a p53-silencing background, MCT-1 malignantly transforms normal breast epithelial cells that are satisfactory for stimulating cell migration/ adhesion and tumorigenesis. Detailed analyses of MCT-1 oncogenicity in H1299 p53-null lung cancer cells have shown that ectopically expressed MCT-1 advances xenograft tumorigenicity and angiogenesis, which cannot be completely suppressed by induction of p53. MCT-1 counteracts mutually with p53 at transcriptional levels. Clinical validations confirm that MCT-1 mRNA levels are differentially enriched in comparison between human lung cancer and nontumorigenic tissues. The levels of p53 mRNA are comparatively reduced in a subset of cancer specimens, which highly present MCT-1 mRNA. Our results indicate that synergistic promotions of chromosomal imbalances and oncogenic potency as a result of MCT-1 expression and p53 loss play important roles in tumor development.
Original language | English |
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Pages (from-to) | 536-548 |
Number of pages | 13 |
Journal | Molecular Cancer Research |
Volume | 7 |
Issue number | 4 |
DOIs | |
Publication status | Published - Apr 1 2009 |
ASJC Scopus subject areas
- Molecular Biology
- Oncology
- Cancer Research