Lees SJ, Childs TE, Booth FW. Age-dependent FOXO regulation of p27 expression via a conserved binding motif in rat muscle precursor cells. Am J Physiol Cell Physiol 295: C1238–C1246, 2008; doi:10.1152/ajpcell.00349.2008.—Previously, we have demonstrated that forkhead box O3a (FOXO3a) overexpression increased p27 promoter activity and protein expression, whereas it decreased proliferation in mus...

Drugs currently approved to coat stents used in percutaneous coronary interventions do not discriminate between proliferating vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). This lack of discrimination delays reendothelialization and vascular healing, increasing the risk of late thrombosis following angioplasty. We developed a microRNA-based (miRNA-based) approach to inhibit p...

BACKGROUND To determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis. METHODS Real-time PCR and immunohistochemistry were used to examine the mRNA and protein expressions of p27 in NPC and nasopharyngeal tissues. The relationship of p27 expression levels with clinical fea...

Overactivation of Ras pathways contributes to oncogenesis and metastasis of epithelial cells in several ways, including interference with cell cycle regulation via the CDK inhibitor p27(Kip1) (p27) and disruption of transforming growth factor beta (TGF-beta) anti-proliferative activity. Here, we show that at high expression levels, constitutively active N-Ras induces cytoplasmic mislocalization...

BACKGROUND: G1/S cell cycle progression requires p27Kip1 (p27) proteolysis, which is triggered by its phosphorylation on threonine (Thr) 187. Since its levels are abundant in quiescent and scarce in cycling cells, p27 is an approved marker for quiescent cells, extensively used in histopathology and cancer research. METHODS: However here we showed that by using a specific phosphorylation site (p...

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of p27(kip1) (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen pe...

Purpose: p27(p27) is a universal cyclin-dependent kinase inhibitor that inhibits cell cycle transition from G1 to S phase and is primarily regulated at the post-transcriptional level via the ubiquitin-proteasome pathway. In vitro data suggest that p27 degradation may be accelerated by the c-Jun activation domain binding protein-1 (JAB1), originally identified as a coactivator of the gene regula...

We have investigated the role of the cyclin-dependent kinase inhibitor, p27(Xic1), in the coordination of cell cycle exit and differentiation during early neurogenesis. We demonstrate that p27(Xic1) is highly expressed in cells destined to become primary neurones and is essential for an early stage of neurogenesis. Ablation of p27(Xic1) protein prevents differentiation of primary neurones, whil...

It is believed that Rb blocks G1-S transition by inhibiting expression of E2F regulated genes. Here, we report that the effects of E2F repression lag behind the onset of G1 cell cycle arrest in timed Rb reexpression experiments. In comparison, kinase inhibitor p27Kip1 protein accumulates with a faster kinetics. Conversely, Rb knockout leads to faster p27 degradation. Rb interacts with the N ter...

The cell-cycle effects of mTORC1 are not fully understood. We provide evidence that mTOR-raptor phosphorylates SGK1 to modulate p27 function. Cellular mTOR activation, by refeeding of amino acid-deprived cells or by TSC2 shRNA, activated SGK1 and p27 phosphorylation at T157, and both were inhibited by short-term rapamycin treatment and by SGK1 shRNA. mTOR overexpression activated both Akt and S...