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)

Chronic neutrophil-predominant inflammation and hypersecretion of mucus are common pathophysiological features of cystic fibrosis, chronic bronchitis, and viral- or pollution-triggered asthma. Neutrophils release elastase, a serine protease, that causes increased mucin production and secretion. The molecular mechanisms of elastase-induced mucin production are unknown. We hypothesized that as part of this mechanism, elastase upregulates expression of a major respiratory mucin gene, MUC5AC. A549, a human lung carcinoma cell line that expresses MUC5AC mRNA and protein, and normal human bronchial epithelial cells in an air-liquid interface culture were stimulated with neutrophil elastase. Neutrophil elastase increased MUC5AC mRNA levels in a time-dependent manner in both cell culture systems. Neutrophil elastase treatment also increased MUC5AC protein levels in A549 cells. The mechanism of MUC5AC gene regulation by elastase was determined in A549 cells. The induction of MUC5AC gene expression required serine protease activity; other classes of proteases had no effect on MUC5AC gene expression. Neutrophil elastase increased MUC5AC mRNA levels by enhancing mRNA stability. This is the first report of mucin gene regulation by this mechanism.
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PMID:Neutrophil elastase increases MUC5AC mRNA and protein expression in respiratory epithelial cells. 1033 40

Sialyl Lewis antigens (sLe(x/a)) are cancer-associated carbohydrate determinants, serve as ligands of the selectin family and are associated with hematogenous metastasis of cancer. So far, the clinicopathologic values of sialyl Lewis x (sLe(x)) and sialyl Lewis a (sLe(a)) in lung cancer have remained controversial. Using immunohistochemistry, the expressions of sLe(x) and sLe(a) antigens, and an airway mucin (MUC5AC) protein, which was supposed to be the major carrying protein of sialyl Lewis moieties, were studied in surgically resected tumor tissues of 61 patients with stages I or II NSCLC. Thirty-two (52.5%) of the 61 studied subjects were found to be positive for expression of sLe(a), 40 (65.6%) were positive for expression of sLe(x), and 16 (26.2%) were positive for MUC5AC protein. Both the expression of sLe(x) and MUC5AC were associated with adenocarcinoma subtype. Patients bearing tumors with MUC5AC and/or sLe(x) expression had a higher probability of post-operative distant metastasis. Survival analysis demonstrated that patients bearing tumors with expression of sLe(x) antigen or MUC5AC had shorter overall survival. The multivariate logistic regression showed that age >65 years old (OR = 0.207, 95% CI = 0.075-0.569, P = 0.002), nodal status (OR = 6.575, 95% CI = 2.459-17.583, P < 0.001), and MUC5AC (OR = 5.545, 95% CI = 1.998-15.386, P = 0.001) were independent factors affecting survival. We concluded that the expression of sLe(x) was related to MUC5AC protein, while patients with tumors co-expressing both MUC5AC and sLe(x) antigen had the worst survival.
Lung Cancer 2005 Jan
PMID:Sialyl Lewis antigens: association with MUC5AC protein and correlation with post-operative recurrence of non-small cell lung cancer. 1560 55

Sialyl-Lewis x epitopes and MUC5AC protein are known to be overexpressed in mucins secreted by patients suffering from various respiratory diseases. To investigate the mechanisms by which airway inflammatory agents mediate the expression of sialyl-Lewis x epitopes and MUC5AC mucin, we examined the effects of tumor necrosis factor (TNF)-alpha and epidermal growth factor (EGF) in the human lung carcinoma cell line, NCI-H292. Basal expression levels of hST3GalIV, FUT3 and C2/4GnT mRNA, involved in the biosynthesis of sialyl-Lewis x, were higher than those of other glycosyltransferases in NCI-H292 cells. TNF-alpha induced expression of hST3GalIV, FUT3, C2/4GnT and MUC5AC mRNAs in NCI-H292 cells. When cells were pretreated with U73122, a phosphatidylinositol-phospholipase C (PI-PLC) inhibitor, the expression of these glycosyltransferase mRNAs was suppressed. Treating cells with EGF induced the down-regulation of these glycosyltransferase mRNAs and sialyl-Lewis x epitopes, while inducing an increase in expression of MUC5AC mRNA. These EGF-mediated effects on the glycosyltransferase and MUC5AC mRNAs were blocked when cells were first exposed to AG1478, an EGF receptor tyrosine kinase inhibitor. These findings suggest that the expression of sialyl-Lewis x epitopes, which is regulated separately from the expression of MUC5AC protein, may be controlled through pathways such as the EGF receptor tyrosine kinase and PI-PLC signaling cascades in NCI-H292 cells.
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PMID:Regulation of sialyl-Lewis x epitope expression by TNF-alpha and EGF in an airway carcinoma cell line. 1586 35

Gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is an active agent in non-small cell lung cancer, and rapidly relieves bronchorrhea in patients with bronchioloalveolar carcinoma before the improvement of radiological findings. In addition, epidermal growth factor regulates mucin secretion in normal airway goblet cells. The present study was designed to clarify whether gefitinib modifies mucin production in lung cancer cell lines apart from its anti-proliferative effects, using A549 adenocarcinoma and NCI-H292 mucoepidermoid carcinoma cells expressing EGFR and MUC5AC mRNA. Mucin synthesis was measured by RT-PCR and ELISA, and MAPK and Akt, the downstream targets of EGFR, were examined by Western blotting assay. The clinically-achievable concentration of 1muM gefitinib inhibited the growth of both cells by only 10%, but gefitinib suppressed MUC5AC mRNA levels subsequent to a decrease in intracellular and secreted MUC5AC protein. Gefitinib also inhibited the phosphorylation of MAPK and Akt, and the selective inhibitors PD98059 and LY294002 also suppressed MUC5AC protein synthesis. These findings suggest that gefitinib may inhibits MUC5AC synthesis, at least in part, through MAPK and Akt signaling pathways. Thus, gefitinib inhibits mucin production, which is encouraging for trials involving its use against bronchorrhea in patients with lung cancer.
Lung Cancer 2005 Oct
PMID:Gefitinib inhibits MUC5AC synthesis in mucin-secreting non-small cell lung cancer cells. 1600 52