Calcium (Ca(2+)) and calmodulin (CaM) are required for progression of mammalian cells from quiescence into S phase. In multiple cell types, cyclosporin A causes a G(1) cell cycle arrest, implicating the serine/threonine phosphatase calcineurin as one Ca(2+)/CaM-dependent enzyme required for G(1) transit. Here, we show, in diploid human fibroblasts, that cyclosporin A arrested cells in G(1) befo...

AIMS The present study is to detect the expression of cyclin D1 in different clinical molecular subtypes in breast cancer, and to analyze its relationship to the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (Her-2), tumor size, clinical stages, histological grades, age of menarche, and prognosis. METHODS In the present study, we re...

Cyclin D1 plays an important role in the regulation of cell progression through G1 of the cell cycle and has been demonstrated to have oncogenic properties. Using RFLP-PCR, an A/G polymorphism within the cyclin D1 (CCND1) gene was analyzed in 151 sporadic human pituitary tumors, of which 60 were informative at this locus. Further analysis showed that in 15 of 60 (25%) tumors, there was evidence...

The Ink4a/Arf locus encodes two structurally unrelated tumor suppressor proteins, p16 and p14 (murine p19). Invariant inactivation of either the p16-cyclin D/CDK-pRb pathway and/or p53-p14 pathway occurs in most human tumors. Cyclin D1 is frequently overexpressed in breast cancer cells contributing an alternate mechanism inactivating the p16/pRb pathway. Targeted overexpression of cyclin D1 to ...

Cyclin D1 encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the retinoblastoma protein and promotes progression through the G1-S phase of the cell cycle. Amplification or overexpression of cyclin D1 plays pivotal roles in the development of a subset of human cancers including parathyroid adenoma, breast cancer, colon cancer, lymphoma, melanoma, and prostate canc...

Cyclin D1 plays an important role in regulating the progression of cells through the G1 phase of the cell cycle. This gene is frequently overexpressed in human colon cancer. To address the role of cyclin D1 in growth control and tumorigenesis in this disease, we have overexpressed an antisense cyclin D1 cDNA construct in the human colon cancer cell line SW480E8, which expresses high levels of c...

The p53-inducible gene PC3 (TIS21, BTG2) is endowed with antiproliferative activity. Here we report that expression of PC3 in cycling cells induced accumulation of hypophosphorylated, growth-inhibitory forms of pRb and led to G(1) arrest. This latter was not observed in cells with genetic disruption of the Rb gene, indicating that the PC3-mediated G(1) arrest was Rb dependent. Furthermore, (i) ...

introduction: astrocytes, the most abundant glia in the central nervous system, modulate neuronal survival and function. astrocytic functions are mediated by synthesis and secretion of wide ranges of polypeptides through mechanism (s) poorly understood. among these, tgfβs are synthesized and released by the astrocytes. in this study, the involvement of wnt signaling pathway on the synthesis of ...

PURPOSE To analyze the prevalence and clinical relevance of cyclin D3 abnormalities in laryngeal squamous cell carcinoma (LSCC). EXPERIMENTAL DESIGN Cyclin D3 immunoreactivity was evaluated in 223 formalin-fixed and paraffin-embedded samples of LSCC patients with a mean follow-up of 62.8 +/- 43.2 months. The occurrence of cyclin D3 extra signals was analyzed by fluorescence in situ hybridizat...

Although the molecular changes that characterize gliomas have been studied, the pathogenesis of tumor development remains unclear. p21 contributes to gliomagenesis by stabilizing cyclin D1–cdk4 kinase complexes, suggesting that cyclin D1 and cdk4 may also be required for glial tumor development. In this study, we used a mouse model to attempt to confirm this hypothesis, finding that cyclin D1 a...