The aim of the present study was to determine the frequency of p27kip1 promoter methylation in esophageal squamous cell carcinoma (ESCC). The methylation status of the p27kip1 promoter was analyzed by methylation‑specific polymerase chain reaction (MSP) in 50 ESCC and matched non‑tumor tissues. Cell lines were treated with the demethylation agent 5‑aza‑2'‑deoxycytidine (5‑Aza‑CdR) and p27kip1 m...

p27Kip1 is a cyclin-dependent kinase inhibitor that negatively regulates cell proliferation by mediating cell cycle arrest in G1. This study was undertaken to assess the prognostic value of p27Kip1 in localized human prostate cancer. Archival material from 113 radical prostatectomy specimens obtained between 1985 and 1993 was stained immunohistochemically for p27Kip1 protein using a commerciall...

BACKGROUND Low levels of the cyclin-dependent kinase inhibitor p27Kip1 are associated with poor prognosis in cancer. It is unclear whether this is related strictly to p27Kip1-mediated cell cycle inhibition or to other, possibly extranuclear, roles of this protein. In this study, we examined p27Kip1 expression in quiescent and activated lymphocytes. T-cell membranes have been shown to possess sp...

BACKGROUND p27Kip1 plays a major role as a negative regulator of the cell cycle. The regulation of p27Kip1 degradation is mediated by its specific ubiquitin ligase subunits S-phase kinase protein (Skp) 2 and cyclin-dependent kinase subunit (Cks) 1. However, little is known regarding the prognostic utility of p27Kip1, Skp2 and Cks1 expression in renal cell carcinoma. METHODS Immunohistochemist...

BACKGROUND Hypoxia induces the proliferation of pulmonary arterial smooth muscle cell (PASMC) in vivo and in vitro, and prostacyclin analogues are thought to inhibit the growth of PASMC. Previous studies suggest that p27kip1, a kind of cyclin-dependent kinase inhibitor, play an important role in the smooth muscle cell proliferation. However, the mechanism of hypoxia and the subcellular interact...

p27Kip1, a cyclin-dependent kinase inhibitor, is recognized as a negative regulator of the cell cycle. In this paper, we report that overexpression of p27Kip1 triggers apoptosis in several different human cancer cell lines. Using a recombinant adenoviral vector that expresses p27Kip1 (Adp27), we found that overexpression of p27Kip1 in MDA-MB-231 breast cancer cells induces apoptosis that was se...

The one or more underlying mechanisms of the tumor suppressing activity of the histidine triad nucleotide-binding protein 1 (HINT1) are not well defined. In this study we found that HINT1 regulates cellular levels of the cyclin-dependent kinase inhibitor p27KIP1 through multiple mechanisms. Increased expression of HINT1 increases cellular levels of p27KIP1, and HINT1 knockdown with small hairpi...

The B56γ-containing protein phosphatase 2A (PP2A-B56γ) has been postulated to have tumor suppressive functions. Here, we report regulation of p27KIP1 subcellular localization by PP2A-B56γ3. B56γ3 overexpression enhanced nuclear localization of p27KIP1, whereas knockdown of B56γ3 decreased p27KIP1 nuclear localization. B56γ3 overexpression decreased phosphorylation at Thr157 (phospho-Thr157), wh...

PURPOSE To determine whether small interfering (si)RNA downregulation of the cyclin-dependent kinase inhibitor p27kip1 overcomes G(1)-phase arrest and promotes cell-cycle progression in human corneal endothelial cells (HCECs) from young (<30 years old) and older (>60 years old) donors. METHODS Transfection of siRNA was confirmed by incubating confluent cultures of HCECs with FITC-labeled nons...

All-trans-retinoic acid (ATRA), the most biologically active metabolite of vitamin A, controls cell proliferation, apoptosis, and differentiation depending on the cellular context. These activities point to ATRA as a candidate for cancer therapy. A pivotal effect of the molecule is the modulation of p27Kip1, a cyclin-dependent kinase (CDK) inhibitor (CDKI). Here, we investigate the mechanisms b...