p57, Tumorigenesis, and Beckwith-Wiedemann Syndrome Ashley Albright
p57 is a member of the Cip/Kip family of CKIs Encoded by CDKN1C Cyclin/CDK binding domain PAPA Repeat QT domain
The ability of p57 to inhibit Cyclin/CDK suggests it is a tumor suppressor, however p57 levels are high in some cancers
p57 inhibits proliferation by binding and inhibiting CDKs G1-S and G2-M transition Disruption of CDK/cyclin or PCNA binding region reduces ability of p57 to inhibit proliferation
p57 can suppress or promote apoptosis However, other data suggests p57 suppresses pro-apoptotic factors at cell cycle checkpoints
p57 and other Cip/Kip proteins promote cellular migration which leads to tumor metastasis
p57 homozygous mutants cannot exit the cell cycle, allowing cells to become over-proliferative
p57 misregulation can lead to cancer via many pathways DNA methylation and Histone Modifications MicroRNAs Post- translational Modification
CDKN1C has been implicated in Beckwith-Wiedemann Syndrome 1 in 12,000 newborns Primarily due to improper imprinting Classified as an overgrowth syndrome Susceptible to tumors
BWS patients have a higher risk of developing abnormal tissue growth
References "Beckwith-Wiedemann Syndrome." Genetics Home Reference. Accessed March 30, Bilodeau, S., et al. "Distinct Developmental Roles of Cell Cycle Inhibitors P57Kip2 and P27Kip1 Distinguish Pituitary Progenitor Cell Cycle Exit from Cell Cycle Reentry of Differentiated Cells." Molecular and Cellular Biology 29, no. 7 (2009): Cooper, W., et al. "Molecular Subtypes and Phenotypic Expression of Beckwith– Wiedemann Syndrome." European Journal of Human Genetics 13 (2005): Denicourt, C., et al. "Cip/Kip Proteins: More than Just CDKs Inhibitors." Genes & Development 18 (2004): Hatada, I., et al."An Imprinted Gene P57KIP2 Is Mutated in Beckwith–Wiedemann Syndrome." Nature Genetics 14 (1996): Yan, Y., et al. "Ablation of the CDK Inhibitor P57 Kip2 Results in Increased Apoptosis and Delayed Differentiation during Mouse Development." Genes & Development 11 (1997):