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113
Integrin-mediated adhesion regulates ERK nuclear translocation and phosphorylation of Elk-1
- J. Cell
, 2001
"... Abstract. Integrin-mediated adhesion to the extracellular matrix permits efficient growth factor-mediated activation of extracellular signal–regulated kinases (ERKs). Points of regulation have been localized to the level of receptor phosphorylation or to activation of the downstream components, Raf ..."
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Abstract. Integrin-mediated adhesion to the extracellular matrix permits efficient growth factor-mediated activation of extracellular signal–regulated kinases (ERKs). Points of regulation have been localized to the level of receptor phosphorylation or to activation of the downstream components, Raf and MEK (mitogen-activated protein kinase/ERK kinase). However, it is also well established that ERK translocation from the cytoplasm to the nucleus is required for G1 phase cell cycle progression. Here we show that phosphorylation of the nuclear ERK substrate, Elk-1 at serine 383, is anchorage dependent in response to growth factor treatment of NIH 3T3 fibroblasts. Furthermore, when we activated ERK in nonadherent cells by expression of active components of the ERK cascade, subsequent phosphorylation of Elk-1
Induction of cell cycle arrest and apoptosis in HT-29 human colon cancer cells by the dietary compound luteolin. Am J Physiol Gastrointest Liver Physiol 2007;292:G66–75
"... 3,4,5,7-tetrahydroxyflavone found in celery, green pepper, and perilla leaf that inhibits tumorigenesis in animal models. We exam-ined luteolin-mediated regulation of cell cycle progression and apop-tosis in the HT-29 human colon cancer cell line. Luteolin decreased DNA synthesis and viable HT-29 ce ..."
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3,4,5,7-tetrahydroxyflavone found in celery, green pepper, and perilla leaf that inhibits tumorigenesis in animal models. We exam-ined luteolin-mediated regulation of cell cycle progression and apop-tosis in the HT-29 human colon cancer cell line. Luteolin decreased DNA synthesis and viable HT-29 cell numbers in a concentration-dependent manner. It inhibited cyclin-dependent kinase (CDK)4 and CDK2 activity, resulting in G1 arrest with a concomitant decrease of phosphorylation of retinoblastoma protein. Activities of CDK4 and CDK2 decreased within 2 h after luteolin treatment, with a 38% decrease in CDK2 activity (P 0.05) observed in cells treated with 40 mol/l luteolin. Luteolin inhibited CDK2 activity in a cell-free system, suggesting that it directly inhibits CDK2. Cyclin D1 levels decreased after luteolin treatment, although no changes in expression of cyclin A, cyclin E, CDK4, or CDK2 were detected. Luteolin also promoted G2/M arrest at 24 h posttreatment by downregulating cyclin
The oncoprotein kinase chaperone CDC37 functions as an oncogene in mice and collaborates with both c-myc and cyclin D1 in transformation of multiple tissues. Mol Cell Biol 2000, 20: 4462-4473. Available online http://breast-cancer-research.com/content/5/1
"... CDC37 encodes a 50-kDa protein that targets intrinsically unstable oncoprotein kinases including Cdk4, Raf-1, and v-src to the molecular chaperone Hsp90, an interaction that is thought to be important for the establishment of signaling pathways. CDC37 is required for proliferation in budding yeast a ..."
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CDC37 encodes a 50-kDa protein that targets intrinsically unstable oncoprotein kinases including Cdk4, Raf-1, and v-src to the molecular chaperone Hsp90, an interaction that is thought to be important for the establishment of signaling pathways. CDC37 is required for proliferation in budding yeast and is coexpressed with cyclin D1 in proliferative zones during mouse development, a finding consistent with a positive role in cell proliferation. CDC37 expression may not only be required to support proliferation in cells that are develop-mentally programmed to proliferate but may also be required in cells that are inappropriately induced to initiate proliferation by oncogenes. Here we report that mouse mammary tumor virus (MMTV)-CDC37 transgenic mice develop mammary gland tumors at a rate comparable to that observed previously in MMTV-cyclin D1 mice. Moreover, CDC37 was found to collaborate with MMTV–c-myc in the transformation of multiple tissues, including mammary and salivary glands in females and testis in males, and also collaborates with cyclin D1 to transform the female mammary gland. These data indicate that CDC37 can function as an oncogene in mice and suggests that the establishment of protein kinase pathways mediated by Cdc37-Hsp90 can be a rate-limiting event in epithelial cell transformation. Extracellular signals act to coordinate proliferation during the first gap (G1) phase of the cell division cycle. These signals
The roles of cyclin A2, B1, and B2 in early and late mitotic events
- Mol Biol Cell
, 2010
"... Here we have used siRNAs and time-lapse epifluorescence microscopy to examine the roles of various candidate mitotic cyclins in chromatin condensation in HeLa cells. Knocking down cyclin A2 resulted in a substantial (7 h) delay in chromatin condensation and histone H3 phosphorylation, and expressing ..."
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Here we have used siRNAs and time-lapse epifluorescence microscopy to examine the roles of various candidate mitotic cyclins in chromatin condensation in HeLa cells. Knocking down cyclin A2 resulted in a substantial (7 h) delay in chromatin condensation and histone H3 phosphorylation, and expressing an siRNA-resistant form of cyclin A2 partially rescued chromatin condensation. There was no detectable delay in DNA replication in the cyclin A2 knockdowns, arguing that the delay in chromatin condensation is not secondary to a delay in S-phase completion. Cyclin A2 is required for the activation and nuclear accumulation of cyclin B1-Cdk1, raising the possibility that cyclin B1-Cdk1 mediates the effects of cyclin A2. Consistent with this possibility, we found that chromatin condensation was tightly associated temporally with the redistribution of cyclin B1 to the nucleus. Moreover, a constitutively nuclear cyclin B1 rescued chromatin condensation in cyclin A2 knockdown cells. On the other hand, knocking down cyclin B1 delayed chromatin condensation by only about one hour. Our working hypothesis is that active, nuclear cyclin B1-Cdk1 normally cooperates with cyclin A2 to bring about early mitotic events. Because cyclin A2 is present only during the early stages of mitosis, we asked whether cyclin B knockdown might have more dramatic defects on late mitotic events. Consistent with this possibility, we found that cyclin B1- and cyclin B1/B2-knockdown cells had difficulty in maintaining a mitotic arrest in the presence of nocodazole. Taken together, these data suggest that cyclin A2 helps initiate mitosis, in part through its effects on cyclin B1, and that cyclins B1 and B2 are particularly critical for the maintenance of the mitotic state.
Functional collaboration between different cyclin-dependent kinase inhibitors suppresses tumor growth with distinct tissue specificity
- Mol. Cell. Biol
"... The presence of two families of seven distinct mammalian cyclin-dependent kinase (CDK) inhibitor genes is thought to mediate the complexity of connecting a variety of cellular processes to the cell cycle control pathway. The distinct pattern of tissue expression of CDK inhibitor genes suggests that ..."
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The presence of two families of seven distinct mammalian cyclin-dependent kinase (CDK) inhibitor genes is thought to mediate the complexity of connecting a variety of cellular processes to the cell cycle control pathway. The distinct pattern of tissue expression of CDK inhibitor genes suggests that they may function as tumor suppressors with different tissue specificities. To test this hypothesis, we have characterized two strains of double mutant mice lacking either p18INK4c and p27KIP1 or p18INK4c and p21CIP1/WAF1. Loss of both p18 and p27 function resulted in the spontaneous development by 3 months of age of at least eight different types of hyperplastic tissues and/or tumors in the pituitary, adrenals, thyroid, parathyroid, testes, pancreas, duode-num, and stomach. Six of these hyperplastic tissues and tumors were in endocrine organs, and several types of tumors routinely developed within the same animal, a phenotype reminiscent of that seen in combined human multiple endocrine neoplasia syndromes. The p18-p21 double null mice, on the other hand, developed pituitary adenomas, multifocal gastric neuroendocrine hyperplasia, and lung bronchioalveolar tumors later in life. G1 CDK2 and CDK4 kinase activities were increased in both normal and neoplastic tissues derived from mice lacking individual CDK inhibitors and were synergistically stimulated by the simultaneous loss of two CDK inhibitors. This indicates that an increase in G1 CDK kinase activity is a critical step during but is not
Reversal of growth suppression by p107 via direct phosphorylation by cyclin D1/ cyclin-dependent kinase 4
, 2002
"... This article cites 65 articles, 37 of which can be accessed free at: ..."
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Cited by 9 (1 self)
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This article cites 65 articles, 37 of which can be accessed free at:
Reduction of cytosolic p27(Kip1) inhibits cancer cell motility, survival, and tumorigenicity. Cancer Res
, 2006
"... Updated Version Access the most recent version of this article at: doi: 10.1158/0008-5472.CAN-05-3304 ..."
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Cited by 7 (1 self)
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Updated Version Access the most recent version of this article at: doi: 10.1158/0008-5472.CAN-05-3304
DiCicco-Bloom E: Pituitary adenylate cyclase activating polypeptide anti-mitogenic signaling in cerebral cortical progenitors is regulated by p57Kip2-dependent CDK2 activity
- J Neurosci
"... Generation of distinct cell types and numbers in developing cerebral cortex is subject to regulation by extracellular factors that positively or negatively control precursor proliferation. Although signals stimulating proliferation are well described, factors halting cell cycle progression are less ..."
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Generation of distinct cell types and numbers in developing cerebral cortex is subject to regulation by extracellular factors that positively or negatively control precursor proliferation. Although signals stimulating proliferation are well described, factors halting cell cycle progression are less well defined. At the molecular level, production and association of cyclins, cyclindependent kinases (CDKs), and CDK inhibitors (CKIs) regulate cycle progression. We now report that the endogenous peptide, pituitary adenylate cyclase activating polypeptide (PACAP), negatively regulates the cell cycle by inhibiting p57 Kip2-dependent CDK2 activity in embryonic cortex. Protein levels of CDK2 and members of the CIP/KIP family of CKIs (p27 Kip1, p57 Kip2) were detected in developing rat cortex from embryonic day 13.5 through postnatal day 2. With advancing development, CDK2 protein levels decreased, whereas CKI expression
Stem cell factor inhibits erythroid differentiation by modulating the activity of G1-cyclin-dependent kinase complexes: a role for p27 in erythroid differentiation coupled G1 arrest. Cell Growth Differ
, 2000
"... Terminal erythroid differentiation is accompanied by decreased expression of c-Kit and decreased proliferation of erythroid progenitor cells. Using a newly established erythroleukemia cell line HB60-5, which proliferates in response to erythropoietin (Epo) and stem cell factor (SCF) and differentiat ..."
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Terminal erythroid differentiation is accompanied by decreased expression of c-Kit and decreased proliferation of erythroid progenitor cells. Using a newly established erythroleukemia cell line HB60-5, which proliferates in response to erythropoietin (Epo) and stem cell factor (SCF) and differentiates when stimulated with Epo alone, we characterized several events associated with the cell cycle during erythroid differentiation. Forty-eight h after SCF withdrawal and Epo stimulation, there was strong inhibition of cyclin-dependent kinase (cdk) 4 and cdk6 activities, associated with an increase in the binding of p27 and p15 to cdk6. A significant increase in the binding of p27 to cyclin E- and cyclin A-associated cdk2 correlated with the inhibition of these kinases. In addition, the expression of c-Myc and its downstream transcriptional target Cdc25A were found to be down-regulated during Epo-induced terminal differentiation of HB60-5 cells. The loss of Cdc25A was associated with an increase in the phosphotyrosylation of cyclin E-associated cdk2, which may contribute to cell cycle arrest during differentiation. Although overexpression of p27 in HB60-5 cells caused G1 arrest, it did not promote terminal erythroid differentiation. Thus, the cell cycle arrest that involves p27 is part of a broader molecular program during HB60-5 erythroid differentiation. Moreover, we suggest that SCF stimulation of erythroblasts, in addition to inhibiting erythroid differentiation, activates parallel or sequential signals responsible for maintaining cyclin/cdk activity.
Retinoic acid induces neuronal differentiation of embryonal carcinoma cells by reducing proteasome-dependent proteolysis of the cyclin dependent inhibitor p27
- Cell Growth Differ
"... Retinoic acid (RA) treatment of embryonal carcinoma cell line NTERA-2 clone D1 (NT2/D1) induces growth arrest and terminal differentiation along the neuronal pathway. In the present study, we provide a functional link between RA and p27 function in the control of neuronal differentiation in NT2/D1 c ..."
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Retinoic acid (RA) treatment of embryonal carcinoma cell line NTERA-2 clone D1 (NT2/D1) induces growth arrest and terminal differentiation along the neuronal pathway. In the present study, we provide a functional link between RA and p27 function in the control of neuronal differentiation in NT2/D1 cells. We report that RA enhances p27 expression, which results in increased association with cyclin E/cyclindependent kinase 2 complexes and suppression of their activity; however, antisense clones, which have greatly reduced RA-dependent p27 inducibility (NT2p27AS), continue to synthesize DNA and are unable to differentiate properly in response to RA as determined by lack of neurite outgrowth and by the failure to modify surface antigens. As to the mechanism involved in RA-dependent p27 upregulation, our data support the concept that RA reduces p27 protein degradation through the ubiquitin/proteasome-dependent pathway. Taken together, these findings demonstrate that in embryonal carcinoma cells, p27 expression is required for growth arrest and proper neuronal differentiation. Received 6/8/00; revised 8/30/00; accepted 8/31/00. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
