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Drug
Enzyme
Compound
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Query: EC:4.1.1.17 (
ornithine decarboxylase
)
6,351
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The mitogenic role of estradiol on the growth of colon cancer was examined in mice. Sham-operated or ovariectomized mice were injected with cancer cells and received estradiol treatment. Tumor growth was noted: tumor weights were higher in female than male mice. The growth of the tumors was least in ovariectomized mice and highest in estradiol-treated ovariectomized mice. Tumor messenger RNA (mRNA) levels for
ornithine decarboxylase
(
ODC
) and proto-oncogenes c-myc,
c-fos
, and H-ras were examined. Two transcripts (2.2 and 2.7 kilobase pairs) of
ODC
were observed. The steady-state mRNA levels for
ODC
paralleled the changes observed in the weight of the tumors in all groups of animals. Less dramatic changes were observed in c-myc mRNA levels. No significant differences were observed in the mRNA levels for H-ras and
c-fos
. It thus appears likely that an increase in the
ODC
mRNA levels and, to a lesser extent, an increase in c-myc mRNA levels may be some of the important mechanisms by which estradiol mediates its growth effects on colon cancer cells in vivo.
...
PMID:Estradiol is trophic for colon cancer in mice: effect on ornithine decarboxylase and c-myc messenger RNA. 145 76
The mechanism of a sialagogue-induced increase in
ornithine decarboxylase
(
ODC
) activity and the expressions of proto-oncogenes in murine parotid gland were investigated by use of isoproterenol (IPR), carbachol (CC), and methoxamine (MTX). The results were as follows: (1) The three sialagogues had similar effects on the parotid in vivo (mouse parotid after a single injection of IPR) and/or in vitro (rat parotid explants cultured on siliconized lens paper floating on 199 medium containing IPR, CC, or MTX), the order of their effectiveness being IPR > CC > MTX. (2) Northern/dot and Western blot analyses revealed that the sialagogues elevated the steady-state levels of
ODC
mRNA and
ODC
protein to maxima at two h and six h, respectively, after stimulation. The increases were roughly proportional to those in
ODC
activity, suggesting that sialagogue-dependent enzyme induction is regulated at the transcriptional level. (3) The mRNAs of four of nine proto-oncogenes examined showed sialagogue-dependent increases to maxima at 30 min (
c-fos
) or 60 min (c-jun, c-myc, and c-src) after the beginning of stimulation. These increases were all transient, with the levels returning to the control values (without sialagogue) within 60 min. (4) The IPR-dependent elevations of
ODC
activity and the mRNAs of
ODC
,
c-fos
, and c-jun were inhibited by monensin, but not by polymyxin B. On the other hand, the CC-dependent increases in these parameters were inhibited by polymyxin B but not by monensin.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Effects of sialagogues on ornithine decarboxylase induction and proto-oncogene expression in murine parotid gland. 145 88
The expression of a set of cell cycle dependent (CCD) genes (
c-fos
, c-myc,
ornithine decarboxylase
(
ODC
), and thymidine kinase (TK)) was comparatively studied in cultured arterial smooth muscle cells (SMC) during exit from quiescence and exponential proliferation. These genes, which were not expressed in quiescent SMC, were chronologically induced after serum stimulation.
c-fos
mRNA were rapidly and transiently expressed very early in the G1 phase; c-myc and
ODC
peaked a few hours after serum stimulation and then remained at an intermediary level throughout the first cell cycle; TK mRNA and activity then appeared at the G1/S boundary and peak in G2/M phases. Except for
c-fos
, the other genes were also expressed in asynchronously cycling SMC (ACSMC); their expression was studied in elutriated subpopulations representative of cell cycle progression.
c-fos
mRNA were undetectable in any sorted subpopulations, even in the pure early G1 population. Despite a slight increase as the cell cycle advanced, c-myc and
ODC
genes were expressed throughout the ACSMC cell cycle. A faint TK activity was found in G1 subpopulations and increased in populations enriched in other phases; in contrast, TK mRNA remained highly expressed in all elutriated subpopulations. This study demonstrates significant modulations in CCD gene expression between quiescent stimulated and asynchronously cycling SMC in culture. This suggests that the events occurring during the emergence of SMC from quiescence are probably different from those in the G1 phase of ACSMC.
...
PMID:Cell cycle dependent gene expression in quiescent stimulated and asynchronously cycling arterial smooth muscle cells in culture. 153 80
Rat thyroid cells in culture (FRTL-5 strain) require thyrotropic hormone (TSH) for growth. TSH alone in serum free medium is able to induce DNA synthesis of FRTL-5 cells. DNA synthesis occurs 18-20 hours following TSH stimulation of quiescent cells. Here we demonstrate that two sets of genes, related to the entry of cells in the S phase, are induced by TSH: 1) immediate early genes, such as c-jun and a gene coding for a zinc-finger protein Xrox 20/Egr2, both having a pattern of expression similar to the
c-fos
oncogene; 2) early delayed genes such as
ornithine decarboxylase
(
ODC
), 2F-1, a gene that shows a strong similarity in aminoacid sequence to a mitochondrial ADP/ATP carrier, and the asparagine synthetase gene (TS11). Furthermore, an increased expression of the histone H3 gene, a typical marker of S phase, has been observed in TSH-treated FRTL-5 cells.
...
PMID:TSH is able to induce cell cycle-related gene expression in rat thyroid cell. 154 96
Administration of 1mM sodium butyrate or N6,2'-O-dibutyryladenosine 3':5'-cyclic monophosphate (dbcAMP) inhibits the growth activity of U937 human monoblastoid cells by blocking them at the G1 or at the G1 + G2 phases of the cell cycle, respectively. Both agents induce the differentiation of U937 cells, as proved by the increased expression of the maturation-associated CD11b antigen and by the increased capacity to reduce nitroblue tetrazolium. RNA blot assays indicate that butyrate and dbcAMP decrease the expression of
ornithine decarboxylase
and c-myc genes, and stimulate the expression of the vimentin gene. However, while dbcAMP induces
c-fos
mRNA accumulation, butyrate did not affect the expression of this proto-oncogene.
...
PMID:Comparative effects of butyrate and N6, 2'-O-dibutyryladenosine-3':5'-cyclic monophosphate on growth, differentiation and gene expression in U937 human monoblastoid cells. 165 47
Insulin has recently been reported to function as a complete mitogen for SV40 large T antigen-transformed 3T3 T-cells, designated CSV3-1, but not for nontransformed 3T3 T-cells (H. Wang and R. E. Scott, J. Cell. Physiol., 147: 102-110, 1991). It is now reported that sodium orthovanadate mimics this effect of insulin. For example, when exposed to 1-5 microM vanadate, most predifferentiation growth-arrested CSV3-1 cells undergo DNA synthesis within 24 h, but neither vanadate nor insulin induces mitogenesis in nontransformed 3T3 T-cells. To investigate the possible mechanisms by which mitogenesis is induced in CSV3-1 cells, the effects of insulin and vanadate on the expression of growth-related genes were examined. Whereas insulin and vanadate had no effect on the expression of
c-fos
, c-myc, c-jun, jun-B, or
ornithine decarboxylase
activity in nontransformed 3T3 T-cells, insulin and vanadate showed different effects on the expression of these genes in CSV3-1 cells. Insulin induced a rapid and transient accumulation of
c-fos
mRNA followed by induction of c-myc, c-jun, jun-B, and
ornithine decarboxylase
. In contrast, vanadate induced the expression of c-jun, jun-B, and
ornithine decarboxylase
without inducing
c-fos
and c-myc. These observations suggest that SV40 large T antigen may play an important role in insulin- and vanadate-induced mitogenesis and that insulin and vanadate may mediate their mitogenic effects by different signal transduction pathways.
...
PMID:Selective induction of c-jun and jun-B but not c-fos or c-myc during mitogenesis in SV40-transformed cells at the predifferentiation growth arrest state. 166 87
Staurosporine is a potent but nonselective inhibitor of protein kinase C (PKC) and blocks responses to 12-O-tetradecanoylphorbol-13-acetate (TPA) in several cell types in vitro. In cultured primary mouse keratinocytes, however, staurosporine fails to inhibit TPA-mediated keratinocyte maturation and itself elicits responses that are similar to TPA (T. Sako et al., Cancer Res., 48: 4646-4650, 1988). After exposure to 10 nM staurosporine for 24 h, essentially all keratinocytes undergo morphological differentiation, whereas 160 nM TPA induces this response in about 50% of epidermal cells. These concentrations of staurosporine and TPA cause a 4-5-fold induction of epidermal transglutaminase activity and cornified envelopes, both markers of the terminal stage of keratinocyte differentiation. Staurosporine, but not TPA, also induces morphological and biochemical maturation in 2 neoplastic mouse keratinocyte cell lines, 308 and SP-1. The ability of staurosporine to elicit the same responses as TPA suggested that it may be functioning paradoxically as a PKC agonist in intact keratinocytes. In support of this hypothesis, staurosporine induces
ornithine decarboxylase
activity, inhibits 125I-labeled epidermal growth factor binding, and induces expression of
c-fos
mRNA. Down-regulation of PKC by pretreatment of primary keratinocytes with 60 nM bryostatin partially blocks staurosporine-mediated induction of cornified envelopes and inhibition of 125I-labeled epidermal growth factor binding, implicating PKC in these responses. The ability of staurosporine to mimic and/or enhance certain responses to TPA suggests that this agent is acting as a functional PKC agonist in cultured keratinocytes.
...
PMID:Staurosporine induces protein kinase C agonist effects and maturation of normal and neoplastic mouse keratinocytes in vitro. 167 84
Sympathetic nerves and catecholamines exert growth-promoting trophic influences on arterial smooth muscle in vivo, but the molecular signals mediating these trophic effects are unknown. We report here that the alpha-adrenergic agonist phenylephrine (PE) produced dose-dependent stimulation of platelet-derived growth factor A-chain (PDGF-A) gene expression in rat thoracic aorta via agonist occupancy of alpha 1-adrenergic receptors. Increases in aortic PDGF-A mRNA levels were rapid (maximal at 6 h, 10-fold) and transient. Among seven different tissues studied, PE evoked significant increases in PDGF-A mRNA levels only in the aorta. When periaortic fatty/connective tissues normally adherent to thoracic aorta were examined separately from the remaining aortic vessel wall (endothelium removed), stimulated PDGF-A gene expression was found only in vessel wall (presumably smooth muscle). The physiological alpha-adrenergic agonist norepinephrine also increased aortic PDGF-A mRNA levels. Angiotensin II or endothelin, despite producing blood pressure increases similar to PE, had little or no effect on PDGF-A mRNA abundance in rat aorta. PE-stimulated PDGF-A gene expression was accompanied by increased expression of other growth-related genes including
c-fos
, c-myc, and
ornithine decarboxylase
but not DNA synthesis. These results suggest a mechanism for previously described trophic effects of sympathetic nerves and catecholamines on arterial smooth muscle mass, i.e. regulation of growth-related gene expression via alpha 1-adrenergic receptors.
...
PMID:Alpha 1-adrenergic stimulation of platelet-derived growth factor A-chain gene expression in rat aorta. 168 51
The myeloid interleukin-3 (IL-3) dependent cell line, FDC-P1, enters the G0 stage of the cell cycle after IL-3 deprivation for 24 hr. The expression of 13 protooncogenes and immediate-early genes was compared with 4 "control" genes after the addition of either IL-3 or phorbol myristate acetate (PMA) to IL-3-deprived cells. mRNA transcripts encoding c-myc and the T-cell receptor c-gamma gene were induced to high levels only after IL-3 addition, whereas
c-fos
, fos-B, c-jun, jun-B, Krox-20, and Krox-24 were induced transiently only after PMA addition. The remaining genes (fra-1, p53, jun-D, c-Ha-ras, c-Ki-ras, c-raf, beta-actin,
ornithine decarboxylase
, and histone 2B) were detected after culture with either IL-3 or PMA. When cells were serum- and IL-3-deprived,
c-fos
, fos-B, c-jun, jun-B, Krox-20, and Krox-24 were detected after exposure to either serum or PMA. Moreover, culture with cycloheximide and PMA resulted in superinduction of these genes, whereas cycloheximide and IL-3 addition did not. mRNAs encoding these genes had half-lives of 10-20 min after PMA treatment, whereas that of beta-actin was longer (greater than 2 hr), suggesting that short mRNA half-lives contributed to the transient nature of these genes. Although
c-fos
, fos-B, c-jun, jun-B, Krox-20, and Krox-24 expression can be detected in IL-3-dependent cells after exposure to either PMA or serum, these genes were not detected after IL-3 addition, which allows cell-cycle progression. These results document the existence of IL-3 and PMA-responsive genes and demonstrate that IL-3 and protein kinase C agonists can induce distinct patterns of gene expression.
...
PMID:Interleukin-3 and phorbol esters induce different patterns of immediate-early gene expression in an interleukin-3 dependent cell line. 170 18
An increase of proto-oncogene
c-fos
expression in cerebral cortex of rats treated with subconvulsant doses of the pesticide organochlorine lindane (gamma-hexachlorocyclohexane) has been detected using Northern blots. Immunohistochemical studies show that Fos protein was already increased in neuronal nuclei 3 h after treatment. The administration of the benzodiazepine diazepam prior to lindane totally blocked the activation of this proto-oncogene expression. Parallel to this increased expression of
c-fos
an activation of the
ornithine decarboxylase
(
ODC
) gene and enzyme was also observed. High levels of
ODC
mRNA and increased enzyme activity in cortex were found in rats following lindane treatment. These changes were attenuated by prior treatment of animals with diazepam. The co-induction of
c-fos
and
ODC
suggests a potential link between the
ODC
/polyamine system and the short-acting proto-oncogenes in stimulus-transcription coupling events.
...
PMID:c-fos and ornithine decarboxylase gene expression in brain as early markers of neurotoxicity. 171 Jan 64
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