p21 in cancer: intricate networks and multiple activities.

Department of Biochemistry and Molecular Genetics, University of Virginia, School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA.
Nature Reviews Cancer (Impact Factor: 29.54). 06/2009; 9(6):400-14. DOI: 10.1038/nrc2657
Source: PubMed

ABSTRACT One of the main engines that drives cellular transformation is the loss of proper control of the mammalian cell cycle. The cyclin-dependent kinase inhibitor p21 (also known as p21WAF1/Cip1) promotes cell cycle arrest in response to many stimuli. It is well positioned to function as both a sensor and an effector of multiple anti-proliferative signals. This Review focuses on recent advances in our understanding of the regulation of p21 and its biological functions with emphasis on its p53-independent tumour suppressor activities and paradoxical tumour-promoting activities, and their implications in cancer.

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