MadMyc Adenovirus

c-Myc is a very strong proto-oncogene and it is very often found to be upregulated in many types of cancers. It is a mammalian transcription factor belonging to the bHLH (basic Helix Loop Helix)-Leucine Zipper family. The Myc family of cellular oncogenes, which includes c-Myc, N-Myc, L-Myc, S-Myc and B-Myc, represents nuclear transcription factors that play a significant role in cellular proliferation, differentiation, apoptosis and transformation. Members of this gene family are activated upon various mitogenic signals such as Wnt, Shh and EGF. They form heteromeric complexes with other interacting partners, such as members of the Max and Mad families, to activate transcription. Alternatively, c-Myc can also inhibit the DNA binding protein Miz-1 to repress a second set of target genes. Mnt and Mlx regulate Myc activity by forming heterodimers with Max or Mad, respectively, to suppress Myc-induced transcriptional activation.

This adenovirus contain MadMyc, a mutant c-Myc protein that actively represses c-myc target genes. Expression of MadMyc in cycling NIH3T3 cells causes a significant accumulation of cells in G1. The MadMyc-induced G1 arrest is rescued by ectopic expression of cyclin E/CDK2 and cyclin D1/ CDK4, but not by Cdc25A, a known cell cycle target of c-Myc

Reference: Hermeking H., et al., Proc Natl Acad Sci U S A. 2000 Feb 29;97(5):2229-34.