Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Growth-stimulating pathways activated independently of their normal tissue environment are critical to the carcinogenesis and progression of lung cancer. These pathways are comprised of extracellular growth factors; their specific receptors on the cellular membrane; signal transduction cascades in the cytosol; and target molecules, including cytoskeletal proteins, metabolic regulators, and transcription factors in the nucleus. Growth factors can be divided into two groups based on their receptors: G-protein-coupled receptors and receptor tyrosine kinases. Growth factors induce clonal expansion of lung cancer cells by autocrine and/or paracrine mechanisms. Signal transduction cascades form an extremely large and complicated network with cross-talk connections. Ras, phosphatidylinositol-3-OH kinase, and phospholipase C are three key regulators involved in the network. Recent progress in our understanding of the oncoproteins functioning in the pathways has led to the development of novel therapeutic agents. Some of the most exciting results have been obtained with inhibitors of receptor tyrosine kinases. Phase I studies of epidermal growth factor-receptor inhibitors demonstrate objective responses without severe toxicity as single agents in patients with non-small-cell lung cancer refractory to conventional chemotherapy. This new strategy might lead to breakthroughs in the treatment of lung cancer with distant metastases not curable by conventional chemotherapy alone.
Clin Lung Cancer 2001 May
PMID:Growth-stimulating pathways in lung cancer: implications for targets of therapy. 1472 Mar 64

Our prior studies identified co-expression of the human epidermal growth factor-like receptors 2 (ErbB2) and 3 (ErbB3), as well as the growth factor neuregulin-1 (NRG-1) in normal lung epithelium and lung cancers. As ErbB2 and ErbB3 dimerize to produce a high affinity receptor for NRG-1, we postulated that an autocrine growth loop was present in transformed and non-transformed pulmonary epithelial cells. To test this hypothesis, we examined four cell lines derived from human non-small cell carcinomas for: (1) ErbB2 and ErbB3 expression and endogenous activation; (2) NRG-1 expression and secretion/shedding; and (3) the effect of receptor blockade on autocrine receptor activation. Our studies found that ErbB2 and ErbB3 were expressed by each of these cell lines. In addition, the NRG-1 gene was also expressed with both major isoforms of NRG-1 (NRG-1alpha and NRG-1beta) found intracellularly. Only the NRG-1alpha isoform, however, was found secreted/shed into the culture medium. The secreted/shed NRG-1alpha was capable of activating the ErbB2/ErbB3 receptor complex expressed on the breast adenocarcinoma cell line MCF-7. Basal ErbB2 phosphorylation was identified in all lung cancer cell lines and was inhibited with an antibody that blocked the NRG-1 binding site on ErbB3. Taken together, these data show that secreted NRG-1alpha can activate the ErbB2/ErbB3 heterodimer in an autocrine fashion. The identification of a NRG-1alpha/ErbB2/ErbB3 autocrine loop raises the possibility that interruption of this loop may have therapeutic potential in lung cancer.
Lung Cancer 2004 Feb
PMID:Autocrine activation of ErbB2/ErbB3 receptor complex by NRG-1 in non-small cell lung cancer cell lines. 1473 33

Growth factors secreted by either host or tumour cells play a major role in tumour cell progression. Besides stimulating cell division, growth factors may also stimulate cell migration and modulate matrix metalloprotease (MMP) production. MMPs are enzymes involved in a variety of physiological and pathological processes including tumour cell invasion and metastasis. We have previously shown that different growth factors regulate the motile behaviour of human lung cancer cell lines. In order to further advance our knowledge of the role the different growth factors play in lung cancer, we investigated their effect on two key enzymes belonging to the MMP family of enzymes, namely MMP-9 and MMP-2. Serum-free cultures of three human non-small cell lung cancer cell lines were exposed to five different growth factors: insulin-like growth factor I (IGF I) and II (IGF II), hepatocyte growth factor (HGF), epidermal growth factor (EGF) and stem cell factor (SCF). The expression of MMP-9 and MMP-2 in growth factor-treated and untreated cell lines was evaluated using gelatine zymography and quantified using computer-assisted image analyses. We found heterogeneous expression and activity of MMP-9 and MMP-2 in all three lung cancer cell lines. The most important finding in our study is that HGF and EGF are capable of stimulating the conversion of MMP-9 from a latent to an active form in human large cell lung cancer cell line U-1810 [corrected]. IGF I, IGF II, HGF and EGF stimulated an enhanced expression and activity of the latent form of MMP-2 and MMP-9. SCF did not enhance MMP activity in any of the cell lines tested. Our previous studies have shown that IGF I, IGF II, HGF, EGF and SCF induce migration of human non-small cell lung cancer cells in the presence of extracellular matrix (ECM) components. In the present study we show that growth factors can also enhance the expression of MMP's in these cells. Taken together these results indicate that certain growth factors may promote invasiveness through their ability to induce not only cell migration, but also by enhancing the expression and activity of matrix degrading MMP-2 and MMP-9.
 ...
PMID:Growth factor-enhanced expression and activity of matrix metalloproteases in human non-small cell lung cancer cell lines. 1498 39

Lung cancer continues to be the leading cause of cancer death in industrialized countries and there is an urgent need for the development of preventive treatments that inhibit the progression of initiated cells into overt lung cancer in smokers who quit. Murine pulmonary adenocarcinoma models are widely used to test prospective cancer preventive agents. These tumors are of alveolar type II cell lineage, express growth-regulating signal transduction pathways that are stimulated by epidermal growth factor and protein kinase C while being inhibited by agents that increase intracellular cyclic AMP (cAMP). By contrast, pulmonary adenocarcinomas induced in hamsters are derived from bronchial and bronchiolar Clara cells, are under beta-adrenergic receptor control and their development is promoted by agents that increase intracellular cAMP. Adenocarcinomas of either cell lineage develop in humans, raising the possibility that agents with strong chemopreventive activity in murine lung cancer models due to stimulation of cAMP may selectively promote human pulmonary adenocarcinomas derived from Clara cells. We therefore compared the effects of the beta-adrenergic agonist isoproterenol and the activator of cAMP forskolin under controlled in vitro conditions on the human pulmonary adenocarcinoma cell line NCI-H322 which expresses a Clara cell phenotype versus the human pulmonary adenocarcinoma cell line A549 which expresses features of alveolar type II cells. Our data show that isoproterenol significantly stimulated cAMP, ERK1/2 activity and DNA synthesis in NCI-H322 cells and that this response involved transactivation of the EGF receptor. By contrast, we found that isoproterenol had no effect on A549 cells whereas forskolin significantly inhibited DNA synthesis and ERK1/2 activity. Our findings are consistent with the interpretation that human pulmonary adenocarcinomas of Clara cell lineage are highly sensitive to the cancer promoting effects of beta-adrenergic agonists and other agents that stimulate cAMP whereas human cancers of the same histological family but derived from alveolar type II cells are resistant to beta-adrenergic agonists and respond with a reduction in cell growth to stimulation of cAMP. Our findings suggest that some widely advertised cancer preventive agents such as green tea, retinoids and beta-carotenes are unsafe to be used by smokers or by ex-smokers due to their tumor promoting effects via stimulation of cAMP on initiated cells of Clara cell lineage.
 ...
PMID:Antagonistic growth regulation of cell lines derived from human lung adenocarcinomas of Clara cell and aveolar type II cell lineage: Implications for chemoprevention. 1513 89

Lung cancer is the leading cause of death from neoplasia in men and women in the United States. Some studies suggest that women are more susceptible than men to tobacco-induced carcinogenesis and may show higher risk than men for lung cancer development from smoking. More recently, increasing biochemical and genetic data have supported this male-female difference in response to tobacco. Estrogens may be involved in lung carcinogenesis, and estrogen receptors (ERs), mainly ERb, are present and functional in normal lung and tumor cell lines and tissues. Estrogen can directly stimulate the transcription of estrogen-responsive genes in the nucleus of lung cells, and it can also transactivate growth factor signaling pathways, in particular the epidermal growth factor pathway. Lung cancer patients currently have few effective therapeutic options. An understanding of these new developments in estrogen signaling and cross-talk pathways may pave the way for innovative combinatorial approaches for treatment of lung cancer and possibly chemoprevention.
 ...
PMID:Estrogen receptor pathways in lung cancer. 1516 76

Preclinical studies suggest that cyclooxygenase (COX)-2 may be involved in the molecular pathogenesis of some types of lung cancer. Most of the available studies point to its involvement in non-small cell lung cancer. Survival of patients with non-small cell lung cancer expressing high levels of COX-2 is markedly reduced. Treatment of humans with the selective COX-2 inhibitor celecoxib augments the antitumor effects of chemotherapy in patients with non-small cell lung cancer. COX-2 has been shown to regulate some aspects of tumor-associated angiogenesis. Most of the results we have published point to effects on the regulation of vascular endothelial growth factor. However, prostaglandins derived from COX-2 affect other signaling pathways as well, such as the epidermal growth factor and its receptor. Others have recently shown that non-small cell lung cancer exhibits a COX-2 downstream enzyme expression pattern that is altered in lung tumor cells and tumor-supplying vessels. Therefore, COX-2 and prostaglandins may have a major impact on lung tumor progression and tumor-associated inflammation. Clinical trials currently underway are exploring the potential of targeting COX-2 in lung cancer.
 ...
PMID:Cyclooxygenase as a target in lung cancer. 1521 72

HER gene family (HER1-HER4) encodes structurally similar transmembrane proteins (EGFR, HER2, ErB-3, and ErB-4) with tyrosine kinase activity. Dimerised on binding with a number of ligands, including epidermal growth factor (EGF) and transforming growth factor alpha (TGFalpha), these proteins stimulate epithelial cell proliferation. HER2 and EGFR overexpression is detected in the cells of many tumours, mainly in breast, lung and oral cancer and may be connected with HER2 gene amplification or point mutations as well as with the presence of overactive polymorphic forms of HER1 gene. The first medication of a proved efficacy in breast cancer treatment was trastuzumab (Herceptin)--monoclonal antibody against HER2 protein. Trastuzumab was effective only in the case of patients with high HER2 expression evaluated by immunohistochemical methods and with gene amplification ascertained by fluorescence in situ hybridisation assays. In non-small-cell lung cancer (NSCLC), HER2 overexpression was detected only in a few cases. Therefore, trastuzumab treatment seems to be problematic in NSCLC patients. A small molecule quinazoline (erlotinib, Tarceva) is a promising therapeutic agent selectively blocking EGFR. Phase III Tarceva clinical trail in NSCLC patients showed that their survival is prolonged and that the medication acts together with other chemotherapeutic agents like cisplatin and gemcitabine.
 ...
PMID:Anti-HER therapeutic agents in the treatment of non-small-cell lung cancer. 1531 69

Treatment of solid tumors with chemotherapy regimens commonly is associated with debilitating or life-threatening side effects. Careful patient management, appropriate and prompt management of side effects, and interruption of therapy frequently are required for patients receiving chemotherapy. Furthermore, the systemic toxicity associated with chemotherapy may result in irreversible and incapacitating side effects, such as peripheral neuropathy, that lead to poor quality of life in patients. Gefitinib (Iressa, ZD1839, AstraZeneca Pharmaceuticals LP, Wilmington, DE) is a biologically based, molecular targeted therapy with a novel mechanism of action: selective inhibition of the epidermal growth factor receptortyrosine kinase (EGFR-TK) activity. Once-daily oral treatment with gefitinib is well tolerated. In clinical trials, treatment with gefitinib resulted in durable tumor responses and improvement in lung cancer-related symptoms in patients with advanced non-small cell lung cancer who had received prior chemotherapy. Trials are under way to explore the full potential of gefitinib and additional EGFR-TK inhibitors for other solid tumors and in other treatment settings, including prevention. Biologically based, molecular-targeted therapies such as gefitinib are providing new treatment options for patients and adding a new dimension to clinical practice for oncology nurses.
 ...
PMID:New directions in oncology nursing care: focus on gefitinib in patients with lung cancer. 1535 25

(1) Platinum-based chemotherapy is generally used to treat advanced-stage non small-cell lung cancer (stages III and IV), but has only a modest impact on survival. There is no reference treatment. (2) Gefitinib inhibits the tyrosine kinase activity of the receptor for EGF (epidermal growth factor), which is thought to be involved in tumour growth. It has a temporary licence in France and is used on a named-patient basis, but full marketing authorisation has already been granted in Japan, the United States, and elsewhere. (3) Two double-blind dose-finding studies compared two doses of oral gefitinib monotherapy (250 mg/day and 500 mg/day) in patients in whom at least two lines of chemotherapy had failed. The results were favourable, with a median survival of 6 months and a symptomatic improvement in some patients, but they are undermined by the absence of a placebo group and by major protocol violations. (4) Two double-blind trials, each in more than 1000 patients, showed that gefitinib does not increase the efficacy of first-line platinum combinations. (5) About 15% of patients receiving gefitinib monotherapy in clinical trials stopped taking the treatment because of adverse events. The most frequent were gastrointestinal (diarrhea, nausea, vomiting) and cutaneous (rash, acne, dry skin, pruritus). (6) Interstitial pneumonitis occurred in about 1% of patients, and was fatal in about one-third of cases. (7) Gefitinib is metabolised by the cytochrome P450 isoenzyme CYP3A4, so carries a potentially high risk of interactions. (8) In practice, more thorough assessment of gefitinib is needed to determine whether this new drug is beneficial for patients with non small-cell lung cancer. Marketing authorisation is not currently justified.
 ...
PMID:Gefitinib: new preparation. Non small-cell lung cancer: stricter assessment needed. 1549 96

The elevated levels of beta1,4-galactosyltransferase I (GalT I; EC 2.4.1.38) are detected in highly metastatic lung cancer PGBE1 cells compared with its less metastatic partner PGLH7 cells. Decreasing the GalT I surface expression by small interfering RNA or interfering with the surface of GalT I function by mutation inhibited cell adhesion on laminin, the invasive potential in vitro, and tyrosine phosphorylation of focal adhesion kinase. The mechanism by which GalT I activity is up-regulated in highly metastatic cells remains unclear. To investigate the regulation of GalT I expression, we cloned the 5'-region flanking the transcription start point of the GalT I gene (-1653 to +52). Cotransfection of the GalT I promoter/luciferase reporter and the Ets family protein E1AF expression plasmid increased the luciferase reporter activity in a dose-dependent manner. By deletion and mutation analyses, we identified an Ets-binding site between nucleotides -205 and -200 in the GalT I promoter that was critical for responsiveness to E1AF. It was identified that E1AF could bind to and activate the GalT I promoter by electrophoretic mobility shift assay in PGLH7 cells and COS1 cells. A stronger affinity of E1AF for DNA has contributed to the elevated expression of GalT I in PGBE1 cells. Stable transfection of the E1AF expression plasmid resulted in increased GalT I expression in PGLH7 cells, and stable transfectants migrated faster than control cells. Meanwhile, the content of the beta1,4-Gal branch on the cell surface was increased in stably transfected PGLH7 cells. GalT I expression can also be induced by epidermal growth factor and dominant active Ras, JNK1, and ERK1. These data suggest an essential role for E1AF in the activation of the human GalT I gene in highly metastatic lung cancer cells.
 ...
PMID:Elevated beta1,4-galactosyltransferase I in highly metastatic human lung cancer cells. Identification of E1AF as important transcription activator. 1561 Nov 27


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>