Myc as a key signaling node The expression of Biology Diagrams Enforced c-Myc expression promotes inappropriate cell cycle progression of growth factor deprived cells and triggers concomitant apoptosis. However, it is not clear what role dysregulation of the cell cycle plays in c-Myc-induced apoptosis. Ornithine decarboxylase (ODC) is a transcriptional target o โฆ
To gain a clearer understanding of the role of c-Myc in cellular proliferation, we have performed a comprehensive analysis of the components that regulate cell cycle progression. The largest defect observed in c-myc-/- cells is a 12-fold reduction in the activity of cyclin D1-Cdk4 and -Cdk6 complexes during the G0-to-S transition. The activation of STAT3 by the cytokine receptor gp130 is required for both the G1 to S cell cycle transition and antiapoptosis. We found that Pim-1 and Pim-2 are targets for the gp130-mediated STAT3 signal. Expression of a kinase-defective Pim-1 mutant attenuated gp130-mediated cell proliferation. Constitutive expression of Pim-1 together with c-myc, another STAT3 target, fully compensated We will review here the role of MYC as cell-cycle brake releaser i.e., how MYC stimulates cell cycle mainly through the repression of cell-cycle inhibitors . Cell-cycle progression is regulated by serine/threonine protein kinases composed by a catalytic subunit or CDK (cyclin-dependent protein kinase), and a regulatory subunit, the cyclin [ 43
myc expression on cell cycle progression Biology Diagrams
Induction of cell proliferation by promoting G 1 to S-phase transition during cell cycle progression is one of Myc's best characterized functions, a feature linked to its proโoncogenic
The entry in cell cycle of quiescent cells upon Myc enforced expression has been described in many models. Also, the downregulation or inactivation of Myc results in the impairment of cell cycle progression. Given the frequent deregulation of Myc oncogene in human cancer it is important to dissect out the mechanisms underlying the role of Myc An indirect proof of the role of Myc in cell cycle progression is the fact that Mxd proteins (Mxd1, Mxi1, Mxd3, Mxd4 and Mnt), which bind to Myc-binding sites and antagonize Myc transcriptional activity, inhibit cell proliferation (reviewed in [80], [81], [82]). Cell cycle arrest is also observed upon the enforced expression of MadMyc, a
Myc and cell cycle control Biology Diagrams
The role of c-Myc in the cell cycle is further highlighted by the marked prolongation of the doubling time of cells in which both alleles of c-myc were eliminated by homologous Shichiri M, Follansbee M R, Sedivy J M. Effects of c-myc expression on cell cycle progression. Mol Cell Biol. 1994;14:5748-5755. doi: 10.1128/mcb.14.9.5748. We further show that heterogeneity in c-Myc dynamics leads to variable target gene transcription and that timing of c-Myc expression predicts cell-cycle progression rates and drug sensitivities. Together, our data advocate for a model in which cancer cells increase the heterogeneity of functionally diverse transcription factors such as c-Myc to Effects of c-myc expression on cell cycle progression. K D Hanson. K D Hanson. 1 Department of Molecular Biophysics, Yale University School of Medicine, New Dean M., Sonenshein G. E. Cell-cycle control of c-myc but not c-ras expression is lost following chemical transformation. Cell. 1984 Feb;36(2):241-247. doi: 10.1016/0092-8674(84)90217
