Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0684249 (lung carcinoma)
 23,830 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cyclin-dependent kinase inhibitor p21(WAF-1/CIP1/MDA-6) (p21) plays a key role in cell cycle inhibition and apoptosis, and is negatively regulated during cell proliferation. Extracellular matrices can affect cellular proliferation, but their effects on p21 have not been entirely elucidated. Herein, we explore the effects of the matrix glycoprotein fibronectin on p21 expression in human lung carcinoma cells. Our studies show that fibronectin stimulates cell proliferation, and that this effect is associated with suppression of p21 and stimulation of cyclin D1 mRNA and protein levels in human lung non-small lung cell carcinoma cells (H1838). In contrast, the matrix protein collagen type 1 had no effect. The suppression of p21 by fibronectin was blocked by inhibitors of the extracellular signal-regulated kinase pathway (PD98095), and the Rho-kinase pathway (Y-27632). Fibronectin stimulated the phosphorylation of Erk and increased Rho protein expression. To determine the molecular mechanism(s) responsible for the inhibitory effects of fibronectin on p21 expression, transient transfection assays were performed with cells expressing a wild-type human p21 promoter construct. In these cells, fibronectin reduced p21 gene promoter activity. Finally, electrophoresis mobility shift experiments revealed that fibronectin decreased nuclear Sp1 binding activity in the promoter region of the p21 gene promoter, and a Sp1 competing oligonucleotide inhibited the fibronectin response. Taken together, our results suggest that fibronectin stimulates lung cancer carcinoma cell growth by reducing the cyclin-dependent kinase inhibitor p21 and by inducing cyclin D1 gene expression. The reduction of p21 by fibronectin appears to be mediated through Erk and Rho-kinase signaling and DNA-protein interactions at the Sp1 site in the p21 gene promoter. These observations unveil a novel mechanism for p21 gene regulation by fibronectin in lung carcinoma cell growth that represents a potential target for therapy.
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PMID:Fibronectin stimulates human lung carcinoma cell proliferation by suppressing p21 gene expression via signals involving Erk and Rho kinase. 1569 66

Matrix metalloproteinases (MMPs) are believed to play an essential role in cancer invasion, although detailed differences between noninvasive and invasive lung carcinomas are still unclear. To elucidate the expression and activity patterns of MMPs in noninvasive and invasive carcinoma of the lung, we performed in situ hybridization and real-time reverse transcription-polymerase chain reaction to detect messenger RNAs (mRNAs) of MMPs and their tissue inhibitors (TIMPs). The basement membrane was evaluated by immunohistochemistry for type IV collagen. Gelatinase activity was examined by zymography and in situ zymography. A total of 14 surgically resected primary pulmonary adenocarcinomas were used for this study. All the tumors were adenocarcinoma mixed bronchioloalveolar carcinomas according to the 1999 WHO classification. MMP and TIMP2 mRNAs were detected by in situ hybridization in all samples, in both noninvasive and invasive carcinoma components. Signals for MMP mRNAs were significantly higher in both noninvasive and invasive carcinomas than in tumor-free lung tissue. However, the differences were small between noninvasive and invasive carcinomas, not only in the amount of mRNA but also in the activity of the MMPs. In most carcinomas, stromal fibroblast-type cells tended to express levels of MMP and TIMP2 mRNAs that were higher than or at least similar to those expressed in epithelial cells. Our data on mixed adenocarcinoma suggest that noninvasive carcinoma areas already express a molecular mechanism involving MMPs similar to that expressed by invasive carcinoma areas. Stromal fibroblast-type cells seem to be the most important source of MMPs, from the earliest event of tumor invasion by pulmonary adenocarcinomas.
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PMID:Expression and localization of mRNAs for matrix metalloproteinases and their inhibitors in mixed bronchioloalveolar carcinomas with invasive components. 1569 22

We have recently shown that adoptively transferred, IL-2-activated natural killer (A-NK) cells are able to eliminate well-established B16-F10.P1 melanoma lung metastases. However, some B16-F10.P1 lung metastases were resistant to infiltration by the A-NK cells and also resistant to the A-NK cell treatment. The infiltration-resistant (I-R) B16-F10.P1 metastases had a unique "compact" morphology compared to the "loose" morphology of the infiltration-permissive (I-P) metastases. Here, we show that I-P loose tumors and I-R compact tumors are also found in lung metastases of mouse Lewis lung carcinoma (3LL), MCA-102 sarcoma, and MC38 colon carcinoma as well as rat MADB106 mammary carcinoma origin. Furthermore, the infiltration resistance of the compact tumors is not restricted to A-NK cells, since PHA and IL-2 stimulated CD8+ T-cells (T-LAK cells) also infiltrated the compact tumors poorly. Analyses of tumors for extracellular matrix (ECM) components and PECAM-1(+) vasculature, revealed that the I-R lesions are hypovascularized and contain very little laminin, collagen and fibronectin. In contrast, the I-P loose tumors are well-vascularized and they contain high amounts of ECM components. Interestingly, the distribution pattern of ECM components in the I-P loose tumors is almost identical to that of the normal lung tissue, indicating that these tumors develop around the alveolar walls which provide the loose tumors with both a supporting tissue and a rich blood supply. In conclusion, tumor infiltration by activated NK and T cells correlates with the presence of ECM components and PECAM-1(+) vasculature in the malignant tissue. Thus, analysis of the distribution of ECM and vasculature in tumor biopsies may help select patients most likely to benefit from cellular adoptive immunotherapy.
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PMID:Morphological appearance, content of extracellular matrix and vascular density of lung metastases predicts permissiveness to infiltration by adoptively transferred natural killer and T cells. 1604 44

Halothane is a volatile anaesthetic, which is known to induce alterations in cellular plasma membranes, modulating the physical state of the membrane lipids and/or interacting directly with membrane-bound proteins, such as integrin receptors. Integrin-mediated cell adhesion is a general property of eukaryotic cells, which is closely related to cell viability. Our previous investigations showed that halothane is toxic for A 549 lung carcinoma cells when applied at physiologically relevant concentrations and causes inhibition of adhesion to collagen IV. The present study is focused on the mechanisms underlying halothane toxicity. Our results imply that physiologically relevant concentrations of halothane disrupt focal adhesion contacts in A 549 cells, which is accompanied with suppression of focal adhesion kinase activity and paxillin phosphorylation, and not with proteolytic changes or inhibition of vinculin and paxillin expression.We suggest that at least one of the toxic effects of halothane is due to a decreased phosphorylation of the focal contact proteins.
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PMID:Halothane affects focal adhesion proteins in the A 549 cells. 1685 89

Angiogenesis requires the deposition of type IV collagen by endothelial cells into the basement membrane of new blood vessels. Stabilization of type IV collagen triple helix depends on the hydroxylation of proline, which is catalyzed by the iron-containing enzyme prolyl hydroxylase. This enzyme, in turn, requires ascorbic acid to maintain the enzyme-bound iron in its reduced state. We hypothesized that dietary ascorbic acid might be required for tumor angiogenesis and, therefore, tumor growth. Here, we show that, not surprisingly, ascorbic acid is necessary for the synthesis of collagen type IV by human endothelial cells and for their effective migration and tube formation on a basement membrane matrix. Furthermore, ascorbic acid depletion in mice incapable of synthesizing ascorbic acid (Gulo(-/-)) dramatically restricts the in vivo growth of implanted Lewis lung carcinoma tumors. Histopathological analyses of these tumors reveal poorly formed blood vessels, extensive hemorrhagic foci, and decreased collagen and von Willebrand factor expression. Our data indicate that ascorbic acid plays an essential role in tumor angiogenesis and growth, and that restriction of ascorbic acid or pharmacological inhibition of prolyl hydroxylase may prove to be novel therapeutic approaches to the treatment of cancer.
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PMID:Depletion of ascorbic acid restricts angiogenesis and retards tumor growth in a mouse model. 1732 43

The brain is frequently affected by the spread of lung cancer, and haematogenous metastasis is a common route to brain metastasis. We therefore developed an isogenic brain metastasis model of lung cancer to use the Lewis lung carcinoma cell line and analysed dynamics of neoplastic cells after extravasation. Histological analysis revealed two characteristic patterns: metastatic foci exhibiting an angiocentric pattern were designated 'perivascular proliferations'; neoplastic cells infiltrating the brain parenchyma were designated 'invasive proliferations'. Electron microscopic observation of perivascular proliferations showed that neoplastic cells were confined to the perivascular space. In invasive proliferations, however, fragments of collagen fibre were observed in the gaps between neoplastic cells, indicating that the neoplastic cells had disintegrated the pia-glial membrane. We analysed the expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 by using both immunohistochemical analysis and real-time polymerase chain reaction analysis. MMP-2 expression was significantly higher in invasive proliferations. MMP-9 expression was significantly higher in day 7, but there was no significant difference in day 11. The pia-glial membrane and perivascular space are the barriers that neoplastic cells must overcome to infiltrate the brain. In conclusion, our findings suggest that brain metastasis requires two distinct processes.
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PMID:A double three-step theory of brain metastasis in mice: the role of the pia mater and matrix metalloproteinases. 1749 10

Chemokines and their receptors play important roles in various aspects of tumoral processes, and evidence was provided for their critical involvement in determining the metastatic destination of tumor cells. Here, we analyzed in vitro and in vivo, how CCR6 expression could alter the behavior of Lewis lung carcinoma (LLC) cells, which were shown to express low levels of the CCR6 ligand, CCL20 (LARC), both in vitro and in vivo. The expression of CCR6 significantly decreased the number of metastases in immunocompetent C57BL/6 mice, without affecting the tumor-forming ability of LLC cells. This was correlated with a decrease in clonogenicity in soft and hard agar, and with increased adhesion to type-IV collagen. These two observations made in basal conditions were enhanced when CCL20 was added to the assay medium. Thus, expression of CCR6 in tumor cells, associated with the local production of CCL20, decreased the metastatic potential of the LLC line. We propose a model, in which the expression of a chemokine receptor in tumor cells can act as a metastasis-suppressor, or a metastasis-promoting factor, according to the expression, or the absence of expression of the cognate ligand(s) in the tumor.
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PMID:Expression of the chemokine receptor CCR6 in the Lewis lung carcinoma (LLC) cell line reduces its metastatic potential in vivo. 1759 91

Integrin alpha11 (ITGA11/alpha11) is localized to stromal fibroblasts and commonly overexpressed in non-small-cell lung carcinoma (NSCLC). We hypothesized that stromal alpha11 could be important for the tumorigenicity of NSCLC cells. SV40 immortalized mouse embryonic fibroblasts established from wild-type (WT) and Itga11-deficient [knockout (KO)] mice were tested for their tumorigenicity in immune-deficient mice when implanted alone or coimplanted with the A549 human lung adenocarcinoma cells. A549 coimplanted with the fibroblasts showed a markedly enhanced tumor growth rate compared with A549, WT, or KO, which alone formed only small tumors. Importantly, the growth was significantly greater for A549+WT compared with A549+KO tumors. Reexpression of human alpha11 cDNA in KO cells rescued a tumor growth rate to that comparable with the A549+WT tumors. These findings were validated in two other NSCLC cell lines, NCI-H460 and NCI-H520. Gene expression profiling indicated that IGF2 mRNA expression level was >200 times lower in A549+KO compared with A549+WT tumors. Stable short-hairpin RNA (shRNA) down-regulation of IGF2 in WT (WT(shIGF2)) fibroblasts resulted in a decreased growth rate of A549+WT(shIGF2), compared with A549+WT tumors. The results indicate that alpha11 is an important stromal factor in NSCLC and propose a paradigm for carcinoma-stromal interaction indirectly through interaction between the matrix collagen and stromal fibroblasts to stimulate cancer cell growth.
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PMID:Integrin alpha 11 regulates IGF2 expression in fibroblasts to enhance tumorigenicity of human non-small-cell lung cancer cells. 1760 88

Type IV collagen is a major component of vascular basement membranes. The noncollagenous (NC1) domains of several alpha-chains of type IV collagen reveal a capacity to inhibit angiogenesis and tumor growth. Here, we demonstrate that the NC1 domain of the alpha6 chain of type IV collagen (alpha6NC1) is an endogenous inhibitor of angiogenesis and tumor growth. Recombinant alpha6NC1 inhibits human endothelial cell proliferation and neovascularization of Matrigel plugs in mice. The alpha6NC1 suppresses the growth of subcutaneously transplanted Lewis lung carcinoma and also spontaneous pancreatic insulinomas that develop in the Rip1Tag2 mice. Inhibition of tumor growth is associated with significantly diminished microvascular density. Collectively, our results demonstrate that alpha6NC1 is an endogenous inhibitor of angiogenesis and tumor growth.
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PMID:Type IV collagen alpha6 chain-derived noncollagenous domain 1 (alpha6(IV)NC1) inhibits angiogenesis and tumor growth. 1807 49

An abnormal increase in proteolytic enzymes is thought to play a key role in pulmonary emphysema. Alveolar macrophage proteolytic enzymes include cathepsin L, cathepsin S, matrix metalloproteinase 1, 9, and 12, and a number of studies have implicated these proteinases in the alveolar destruction that characterizes emphysema. The aim of this study was to investigate cathepsin L, cathepsin S, matrix metalloproteinase 1, 9, and 12 mRNA expression in alveolar macrophages isolated from patients with varying degrees of emphysema and to correlate their level of expression with measures of emphysema. Alveolar macrophages were isolated from fifty-four patients who underwent surgical resection for lung carcinoma. The level of mRNA expression was determined using real-time PCR. Emphysema was quantified using high-resolution CT scans. Alveolar macrophages were also cultured for 24 h and 48 h; the effect of proinflammatory mediators and promoter polymorphisms on expression was analyzed. There was a significant correlation between matrix metalloproteinase 1 mRNA expression and emphysema. A higher level of matrix metalloproteinase 1 mRNA was associated with more severe emphysema. Matrix metalloproteinase 12 mRNA expression was increased in current smokers as compared with former smokers. Furthermore, there was a negative correlation between matrix metalloproteinase 12 gene expression and carbon monoxide diffusing capacity. The matrix metalloproteinase 9 C-1562T polymorphism significantly influenced matrix metalloproteinase 9 mRNA expression in alveolar macrophages. These results suggest that alveolar macrophage matrix metalloproteinase 1 and 12 may have a role in the lung structural changes leading to the development of emphysema. Furthermore, these data provide evidence to support the concept that multiple proteinases, causing both elastin and collagen degradation, are important in the pathogenesis of pulmonary emphysema.
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PMID:Matrix metalloproteinase expression by human alveolar macrophages in relation to emphysema. 1825 71


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