How is c-Myc activated?
Myc is activated upon various mitogenic signals such as serum stimulation or by Wnt, Shh and EGF (via the MAPK/ERK pathway). By modifying the expression of its target genes, Myc activation results in numerous biological effects.
How does Myc affect the cell cycle?
Promotion of the cell cycle is a major oncogenic mechanism of the oncogene c-MYC (MYC). MYC promotes the cell cycle by not only activating or inducing cyclins and CDKs but also through the downregulation or the impairment of the activity of a set of proteins that act as cell-cycle brakes.
Is Myc a cyclin?
Myc stimulates proliferation and p27 degradation in cells lacking Cdk2 or cyclin E-associated kinase activity. It is known that p27 levels within the cell are mainly controlled by cyclin E-Cdk2, and that Myc mainly relies on cyclin E-Cdk2 activity to phosphorylate p27.
What is the difference between N myc and c-myc?
c-Myc is broadly overexpressed in both blood-borne and solid tumors. N-myc is most frequently overexpressed in solid cancers of neural origin, such as neuroblastoma and glioma.
Is C-MYC an oncogene or proto-oncogene?
The proto-oncogene c-MYC, discovered over a quarter of a century ago as the cellular homolog of the oncogene associated with several avian retroviruses, has a pivotal function in growth control, differentiation and apoptosis and is among the most frequently affected genes in human cancers.
What are myc target genes?
Among the targets of Myc, 107 were nuclear encoded genes involved in mitochondrial biogenesis. Genes with important roles in mitochondrial replication and biogenesis, such as POLG, POLG2, and NRF1 were identified as direct targets of Myc, confirming a direct role for Myc in regulating mitochondrial biogenesis.
How does Myc stimulate the cell cycle?
Several parallel mechanisms account for Myc-mediated stimulation of the cell cycle. First, most of the critical positive cell cycle regulators are encoded by genes induced by Myc. These Myc target genes include Cdks, cyclins and E2F transcription factors.
How does c-Myc affect the cell cycle?
Myc and cell cycle control Soon after the discovery of the Myc gene (c-Myc), it became clear that Myc expression levels tightly correlate to cell proliferation. The entry in cell cycle of quiescent cells upon Myc enforced expression has been described in many models.
Does Myc Enforced expression contribute to cell proliferation?
Soon after the discovery of the Myc gene (c-Myc), it became clear that Myc expression levels tightly correlate to cell proliferation. The entry in cell cycle of quiescent cells upon Myc enforced expression has been described in many models.
How does Myc activate cyclin/CDK?
Apart from its direct effects on the transcription, Myc is able to hyperactivate cyclin/Cdk complexes through the induction of Cdk activating kinase (CAK) and Cdc25 phosphatases. Moreover, Myc antagonizes the activity of cell cycle inhibitors as p21 and p27 through different mechanisms.