Expression of the high mobility group A family member p8 is essential to maintaining tumorigenic potential by promoting cell cycle dysregulation in LβT2 cells

The mechanism by which the HMGA protein p8 facilitates tumorigenesis may be cell cycle dysregulation. Control- (C) L beta T2 cells, which express p8, form tumors at a rate five-times faster than p8-knockdown (p8-KD)-L beta T2 cells. In association with this heightened tumorigenic potential, p8-expressing C-L beta T2 cells avoid G(0)/G(1) arrest and become genetically unstable while p8-KD-L beta T2 cells arrest in G(0)/G(1), become senescent upon overgrowth, and maintain a diploid population. These phenotypic changes correspond to altered cell cycle regulation at the G(1)-to-S transition that may be due to p8-mediated changes in expression of the Cip/Kip family members of cell cycle inhibitors, p21, p27, and p57. (c) 2007 Elsevier Ireland Ltd. All rights reserved.