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Query: UMLS:C0684249 (
lung carcinoma
)
23,830
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
It has been reported that human lung cancers frequently overexpress both the ubiquitous cell cycle transcription factor B-myb and the ubiquitin carboxyterminal hydrolase UCHL1, an enzyme whose expression is normally limited to neurons and neuroendocrine cells in the lung. A possible explanation for the co-expression of these markers is that Uchl1 is subject to transcriptional regulation by B-Myb, and in tumors the ectopic expression of UCHL1 is a direct consequence of B-Myb overexpression. We have tested this hypothesis in the mouse model system by cloning the murine Uchl1 promoter and analyzing its regulation by murine B-Myb. Expression of a
luciferase
reporter gene driven by the Uchl1 promoter was induced by cotransfected B-Myb, but induction was not dependent on the presence of a myb consensus binding site identified in the promoter region. B-Myb induction was dependent on the context of the Uchl1 TATA box, as has been reported for other genes. Transgenic mice expressing a truncated, constitutively active form of B-Myb in the lung epithelium showed elevated expression of UCHL1 protein. We conclude that B-Myb can stimulate expression of the Uchl1 both in cultured cells and in vivo.
Lung Cancer
2003 Oct
PMID:Stimulation of the murine Uchl1 gene promoter by the B-Myb transcription factor. 1451 83
Polo-like kinase 1 (Plk1) has an important role in the regulation of M phase of the cell cycle. In addition to its cell cycle-regulatory function, Plk1 has a potential role in tumorigenesis. Here we found for the first time that Plk1 physically binds to the tumor suppressor p53 in mammalian cultured cells, and inhibits its transactivation activity as well as its pro-apoptotic function. During the cisplatin-induced apoptosis in human neuroblastoma SH-SY5Y cells, the expression level of Plk1 was significantly decreased both at mRNA and protein levels, whereas cisplatin treatment caused a remarkable stabilization of p53. Systematic immunoprecipitation analyses using a series of deletion mutants of p53 revealed that a sequence-specific DNA-binding region of p53 is required and sufficient for the physical interaction with Plk1. The ectopically overexpressed Plk1 was co-localized with the endogenous p53 in mammalian cell nucleus, as shown by confocal laser microscopy. Expression of exogenous Plk1 and p53 in p53-deficient
lung carcinoma
H1299 cells greatly decreased the p53-mediated transcription from the p53-responsive p21(WAF1), MDM2, and BAX promoters, whereas the kinase-deficient mutant form of Plk1 failed to reduce the transcriptional activity of p53. Consistent with the
luciferase
reporter analysis, Plk1 had an ability to block the p53-dependent induction of the endogenous p21(WAF1). In addition, Plk1 inhibited the pro-apoptotic function of p53 in H1299 cells. Intriguingly, Plk1-mediated repression of p53 was attenuated with ATM. Thus, our present findings strongly suggest that p53 is a critical target of Plk1, and its function is abrogated through the physical interaction with Plk1.
...
PMID:Polo-like kinase 1 (Plk1) inhibits p53 function by physical interaction and phosphorylation. 1502 21
Human small cell
lung carcinoma
(SCLC) tumours exhibit neuroendocrine differentiation, secreting hormones such as ACTH and related peptides. While glucocorticoids inhibit ACTH secretion from the pituitary, this does not occur in SCLC tumours and SCLC cell lines. Failure of glucocorticoids to suppress ACTH peptides is accompanied by a global lack of glucocorticoid action in a number of SCLC cell lines. In the human SCLC cell line, COR L103, activation of a human tyrosine aminotransferase (TAT3)-
luciferase
reporter gene is resistant to glucocorticoids despite similar glucocorticoid receptor (GR) expression to the glucocorticoid-sensitive A549 human lung cancer cell line; moreover, the GR is free of deleterious mutations. Over-expression of a wild-type GR restores glucocorticoid regulation of TAT3-
luciferase
, and this is enhanced when the activation function (AF)-2 domain is deleted but much reduced when the AF-1 domain is deleted. This suggests aberrant AF-2 activation domain function. We identified defective steroid receptor co-activator 1 (SRC1) recruitment to the GR AF-2 in COR L103 cells, although SRC1 was successfully recruited to the steroid X receptor with rifampicin, suggesting a defect in the GR. Analysis of other GR C-terminal co-factors identified increased expression of nuclear co-repressor (NCoR) in COR L103 cells. To determine the impact of this, NCoR was over-expressed in A549 cells, where it reduced GR transactivation by 55%. In summary, glucocorticoid resistance is associated with altered SRC protein recruitment and increased expression of NCoR in these SCLC cells, suggesting that glucocorticoid sensitivity may be modified by subtle changes in co-factor recruitment.
...
PMID:Analysis of co-factor function in a glucocorticoid-resistant small cell carcinoma cell line. 1553 25
Uteroglobin (UG, Clara cell secretory protein) is a steroid inducible, multifunctional protein that is secreted by the mucosal epithelia. UG has anti-proliferative and anti-metastatic effects in cancer cells. COX-2, which catalyzes the first step in the synthesis of prostanoids, has been shown to be overexpressed in tumors. This study investigated the effect of UG on the inhibition of COX-2 expression in lung cancer cells. The level of the COX-2 protein and its mRNA were decreased by UG, as demonstrated by Western blot and the RT-PCR, respectively. The EIA shows that UG suppressed PGE2 synthesis. Western blot showed that the NF-kappaB nuclear translocation was inhibited by the transduction of UG. In addition, an EMSA demonstrated the inhibition of the NF-kappaB-DNA binding by UG. The
luciferase
assay showed that UG also inhibited the NF-kappaB-mediated transcription activity. Furthermore, transfection of the lung cancer cell lines with the COX-2 reporter gene constructs demonstrated that the transcription of COX-2 gene was suppressed by UG. These results show that the inhibition of COX-2 expression by UG transduction correlated with the suppression of NF-kappaB activity in the lung cancer cells. This suggests that UG have the possibility for the treatment of lung cancer.
Lung Cancer
2005 May
PMID:Adenovirus-uteroglobin suppresses COX-2 expression via inhibition of NF-kappaB activity in lung cancer cells. 1582 19
We previously reported MUC1 was a cell surface receptor for Pseudomonas aeruginosa, and binding of bacteria to cells was significantly reduced by pretreatment with neutrophil elastase (NE) (Lillehoj EP, Hyun SW, Kim BT, Zhang XG, Lee DI, Rowland S, and Kim KC. Am J Physiol Lung Cell Mol Physiol 280: L181-L187, 2001). The current study was conducted to ascertain NE effects on MUC1 gene transcription, and MUC1 protein synthesis and degradation. A549 human
lung carcinoma
cells treated with NE exhibited significantly higher MUC1 protein levels in detergent lysates compared with cells treated with vehicle alone. Also, MUC1 protein shed into cell-conditioned medium was rapidly and completely degraded by NE. Actinomycin D blocked NE-stimulated increase in MUC1 protein expression, suggesting a mechanism of increased gene transcription that was confirmed by measurement of quantitatively greater MUC1 mRNA levels in NE-treated cells compared with controls. However, NE did not alter MUC1 mRNA stability, implying increased de novo transcription induced by the protease. NE increased promoter activity in A549 cells transfected with MUC1 gene promoter-
luciferase
reporter plasmid. This effect of NE was completely blocked by mithramycin A, an inhibitor of Sp1, as well as mutation of one of the putative Sp1 binding sites in MUC1 promoter located at -99/-90 relative to transcription initiation site. EMSA revealed NE enhanced binding of Sp1 to this 10-bp segment in a time-dependent manner. These results indicate the increase in MUC1 gene transcription by NE is mediated through increase in Sp1 binding to -99/-90 segment of MUC1 promoter.
...
PMID:Neutrophil elastase stimulates MUC1 gene expression through increased Sp1 binding to the MUC1 promoter. 1584 14
MYCN belongs to the MYC family of proto-oncogenes, which encode for transcription factors of the basic-helix-loop-helix-zipper (bHLHZ) class and is fundamental in the development of the peripheral and central nervous systems (PNS and CNS). While Myc is ubiquitous, MYCN has a very restricted expression pattern: it is mainly expressed during embryonic development, but then becomes downregulated, while in adults it is usually detected in B-cell development. Identification of selective inhibitors of MYCN and its mRNA and protein could be important for the development of more specific, effective and less toxic therapeutic agents for tumors of the PNS and CNS. In children, the most common tumors of the PNS and CNS are neuroblastomas and medulloblastomas, respectively. About 30% of neuroblastoma (NB) tumors present MYCN amplification/over-expression, which is associated with rapid progression and poor prognosis. N-Myc is essential during neurogenesis for the rapid expansion of progenitor cells in the brain. MYCN amplification and over-expression has been reported in medulloblastoma, and especially in the desmoplastic type. Other tumors associated with MYCN overexpression include retinoblastoma, small cell
lung carcinoma
, glioblastoma and certain embryonal tumors. A cell-based, N-Myc-dependent
luciferase
reporter gene assay to identify specific N-Myc small-molecule inhibitors has allowed identification of five compounds showing significant activity. Antisense oligodeoxynucleotides have been shown to inhibit N-Myc production and anti-tumoral activity in vitro and in vivo for NB. Peptide nucleic acids (PNA), which belong to the most recent (third) generation of nucleic acid therapeutics, form highly stable duplexes with DNA and RNA, and are resistant to degradation by nucleases and proteases. Encouraging results have been reported utilizing a PNA-based antisense strategy for inhibition of N-Myc expression in neuroblastoma.
...
PMID:The MYCN oncogene as a specific and selective drug target for peripheral and central nervous system tumors. 1597 48
Several metal ions that are carcinogenic affect cellular iron homeostasis by competing with iron transporters or iron-regulated enzymes. Some metal ions can mimic a hypoxia response in cells under normal oxygen tension, and induce expression of HIF-1alpha-regulated genes. This study investigated whether 12 metal ions altered iron homeostasis in human
lung carcinoma
A549 cells as measured by an activation of IRP-1 and ferritin level. We also studied hypoxia signaling by measuring HIF-1alpha protein levels, hypoxia response element (HRE)-driven
luciferase
reporter activity, and Cap43 protein level (an HIF-1alpha responsive gene). Our results show the following: (i) Ni(II), Co(II), V(V), Mn(II), and to a lesser extent As(III) and Cu(II) activated the binding of IRP-1 to IRE after 24 h, while the other metal ions had no effect; (ii) 10 of 12 metal ions induced HIF-1alpha protein but to strikingly different degrees. Two of these metal ions, Al(III) and Cd(II), did not induce HIF-1alpha protein; however, as indicated below, only Ni(II), Co (II), and to lesser extent Mn(II) and V(V) activated HIF-1alpha-dependent transcription. The combined effects of both [Ni(II) + As(III)] and [Ni(II) + Cr(VI)] on HIF-1alpha protein were synergistic; (iii) Addition of Fe(II) with Ni(II), Co(II), and Cr(VI) attenuated the induction of HIF-1alpha after 4 h treatment; (iv) Ni(II), Co(II), and Mn(II) significantly decrease ferritin level after 24 h exposure; (v) Ni(II), Co(II), V(V), and Mn(II) activated HRE reporter gene after 20 h treatment; (vi) Ni(II), Co(II), V(V), and Mn(II) increased the HIF-1-dependent Cap43 protein level after 24 h treatment. In conclusion, only Ni (II), Co (II), and to a lesser extent Mn(II) and V(V) significantly stabilized HIF-1alpha protein, activated IRP, decreased the levels of ferritin, induced the transcription of HIF-dependent reporter, and increased the expression of Cap43 protein levels (HIF-dependent gene). The mechanism for the significant stabilization and elevation of HIF-1alpha protein which drives these other parameters was previously shown by us and others to involve a loss of cellular Fe as well as inhibition of HIF-1alpha-dependent prolyl hydroxylases which target the binding of VHL ubiquitin ligase and degrade HIF-1alpha. Even though there were small effects of some of the other metals on IRP and HIF-1alpha, downstream effects of HIF-1alpha activation and therefore robust hypoxia signaling were only observed with Ni(II), Co(II), and to much lesser extents with Mn(II) and V(V) in human A549 lung cells. It is of interest that the metal ions that were most effective in activating hypoxia signaling were the ones that were poor inducers of metallothionein protein and also decreased Ferritin levels, since both of these proteins can bind metal ions and protect the cell against toxicity in human lung cells. It is important to study effects of these metals in human lung cells since this represents a major route of human environmental and occupational exposure to these metal ions.
...
PMID:Effects of 12 metal ions on iron regulatory protein 1 (IRP-1) and hypoxia-inducible factor-1 alpha (HIF-1alpha) and HIF-regulated genes. 1638 71
The role of specific stromal-derived matrix metalloproteinases (MMPs) was analyzed in experimental metastasis assays in wild-type and either MMP-9, MMP-7, or MMP-2 null mice. MMP-9 null mice showed an 81% reduction in Lewis
lung carcinoma
tumor number, whereas MMP-7 null mice showed a 42% increase in tumor number, and there was no difference in tumor number in MMP-2 null mice compared with wild-type controls. Similarly, in an orthotopic model of lung cancer, 50% fewer MMP-9 null mice were able to establish tumors in the lung compared with control mice, although the size of the tumors was not different. The effect of MMP-9 on lung tumor colonization was dependent on the expression of MMP-9 from bone marrow-derived cells and is most likely contributed by neutrophils. To examine temporal effects of stromal MMP-9, bioluminescence imaging from
luciferase
-expressing human lung cancer-derived A549 cells revealed that there were fewer tumor cells in the lungs of MMP-9 null mice as early as 19 hours after injection compared with control mice, with no difference in subsequent growth rates. Six hours after injection of tumor cells, MMP-9 null mice showed a 4-fold increase in the percent of tumor cells undergoing apoptosis compared with control mice. We conclude that MMP-9 from the bone marrow contributes to the early survival and establishment of tumors in the lung and has no effect on subsequent growth. These results provide insights into the failure of MMP inhibitors in clinical trials in patients with late-stage lung cancer.
...
PMID:Matrix metalloproteinase-9 from bone marrow-derived cells contributes to survival but not growth of tumor cells in the lung microenvironment. 1639 39
Although obesity is known as a risk factor for several human cancers, the association of obesity with cancer recurrence and metastasis remains to be characterized. Here, B16-BL6 melanoma and Lewis
lung carcinoma
cells were intravenously injected into diabetic (db/db) and obese (ob/ob) mice. The number of experimental lung colonies was markedly promoted in these mice when compared with C57BL/6 mice. In contrast, tumor growth at the implanted site was comparable when cells were inoculated orthotopically. The use of B16-BL6 cells stably transfected with the
luciferase
gene revealed that the increased metastasis reflected a difference mainly within 6 hr after the intravenous inoculation of tumor cells. Administration of recombinant leptin in ob/ob mice abolished the increase in metastasis early on as well as the decrease in the splenic NK cell number. In addition, depletion of NK cells by an anti-asialo-GM1 antibody abrogated the enhanced metastasis in db/db mice. These results demonstrate that metastasis is markedly promoted in diabetic and obese mice mainly because of decreased NK cell function during the early phase of metastasis.
...
PMID:Severe pulmonary metastasis in obese and diabetic mice. 1699 95
Hypoxia, a hallmark of many solid tumors, is associated with angiogenesis and tumor progression. It activates a signal cascade that culminates in the stabilization of hypoxia-inducible factor-1 (HIF-1) transcription factor and activation of genes that possess hypoxia response elements. The loss of tumor suppressors such as p53 has been shown to stabilize HIF-1alpha, which is overexpressed in the majority of human cancers, and its over-expression correlates with poor prognosis and treatment failure. Here we constructed hypoxia-inducible promoters and examined their activities in murine and human cancer cells with variable p53 status. Loss of p53 function in cancer cells resulted in increased HIF-1-dependent transcriptional activity. To investigate the feasibility of exploiting the hypoxic tumor microenvironment for targeted gene therapy of cancer, we constructed retroviral vectors harboring
luciferase
or Escherichia coli cytosine deaminase (CD) genes under the control of the hypoxia-inducible promoter. Murine Lewis
lung carcinoma
(LL2) cells carrying defective p53, when retrovirally transduced with the hypoxia-inducible promoter-driven
luciferase
gene under hypoxic conditions, increased
luciferase
reporter gene expression in vitro and in vivo. Significant antitumor effects were achieved in mice bearing LL2 tumors that expressed CD driven by a hypoxia-inducible promoter after treatment with 5-fluorocytosine. These results suggest the potential applications of suicide genes, such as the CD gene, under the control of hypoxia-inducible promoters for cancer gene therapy, which may target efficiently to hypoxic regions of tumors with p53 mutations.
...
PMID:Hypoxia-induced cytosine deaminase gene expression for cancer therapy. 1718 54
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