Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0149925 (small cell lung cancer)
6,491 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gefitinib ("Iressa", ZD1839) is an orally active, selective epidermal growth factor receptor tyrosine kinase inhibitor, and the single agent is clinically effective in non-small cell lung cancer. Although gefitinib combined with various cytotoxic agents has been reported to enhance cytotoxicity in vitro and in mouse models, the mechanism remains undetermined. Here, to explore the mechanism with topoisomerase I inhibitors, we focused on the efflux pump of the breast cancer resistance protein (BCRP/ABCG2), and then examined whether gefitinib restored drug sensitivity in multidrug-resistant cancer cells overexpressing BCRP. We used PC-6 human small cell lung cancer cells and multidrug-resistant PC-6/SN2-5H cells selected with SN-38 of the active metabolite of irinotecan, and BCRP-overexpressing MCF-7/MX cells selected with mitoxantrone and BCRP cDNA transfectant MCF-7/clone 8 cells. Drug sensitivity against anticancer drugs was determined by tetrazolium dye assay, and intracellular topotecan accumulation by FACScan. The topotecan transport study was done using the plasma membrane vesicles of PC-6/SN2-5H cells. The resistant PC-6/SN2-5H cells overexpressed BCRP but not epidermal growth factor receptor mRNA. Ten micromoles of gefitinib reversed topotecan, SN-38, and mitoxantrone resistance, and increased the intracellular topotecan accumulation in the resistant cells but not in the parental cells. Furthermore, gefitinib inhibited the topotecan transport into the vesicles, and the K(i) value was 1.01 +/- 0.09 micromol/L in the Dixon plot analysis, indicating direct inhibition of BCRP by gefitinib. However, gefitinib was not transported into the vesicles with the high-performance liquid chromatography method. These results indicate that gefitinib reverses BCRP-mediated drug resistance by direct inhibition other than competitive inhibition as a BCRP substrate. Combination of gefitinib and topoisomerase I inhibitors could be clinically effective in cancers expressing BCRP.
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PMID:Gefitinib ("Iressa", ZD1839), an epidermal growth factor receptor tyrosine kinase inhibitor, reverses breast cancer resistance protein/ABCG2-mediated drug resistance. 1573 43

Angiogenesis plays an important role in the pathogenesis of lung cancer. This process is caused by the imbalance between stimulating and inhibiting agents. VEGF is a key stimulator having a biologic effect via two different receptors of tyrosine kinase: VEGF-R1 and VEGF-R2. A soluble form of sVEGF-R1 is a negative regulator of VEGF activity. The serum concentrations of VEGF, sVEGF-R1 were assayed in 24 patients with NSCLC and 13 patients with SCLC and 10 healthy volunteers by means of ELISA method. The serum concentrations of VEGF were significantly higher in patients than in controls (p=0.016). The concentration of sVEGF-R1 was not significantly different in patients and controls. No statistically significant differences were established between the concentrations of VEGF, and sVEGF-R1 with regard to such clinical features, as: performance staging, clinical staging (stage III vs. stage IV) and histological pattern (NSCLC vs. SCLC). The significantly higher VEGF concentrations were reported in patients with the tumor of more than 7.5 cm in the diameter (p=0.027). Analyzing the influence of the response to treatment on the concentrations of parameters examined, a significant increase in VEGF concentration was demonstrated in the case of disease progression (p=0.034). The concentrations of sVEGF-R1 did not change after treatment. No correlation was found between parameters examined.
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PMID:[Circulating VEGF and its soluble receptor sVEGFR-1 in patients with lung cancer]. 1602 92

c-kit, a growth factor receptor with tyrosine kinase activity, plays an important role in the biology of cancer. Its expression has been documented in several malignancies. We performed a retrospective study in 85 patients diagnosed with small cell lung cancer (SCLC) to determine the prevalence and role of c-kit as a possible prognostic marker in this lung cancer malignancy. Demographic and clinical data were obtained from patient charts. c-kit, analyzed as immunohistochemical expression in paraffin-embedded tumour tissues, was observed in 60% of patients. All patients were former or present smokers. At diagnosis, 46% of the patients had limited disease (LD) and 54% extended disease (ED). c-kit expression was observed in 59% of LD and 61% of ED patients (p=0.4). Patients received a median of 4 cycles first-line combination chemotherapy (platinum and etoposide). In LD patients, time to progression (TTP) was 11.5 months in c-kit (+) versus 5.9 in c-kit (-) patients (p=0.14), and median survival 15.4 and 12.8 months, respectively (p=0.33). In the ED group, TTP was 5.5 months in c-kit (+) versus 3.8 in c-kit (-) patients (p=0.34), whereas median survival was 6.3 and 7.9 months, respectively (p=0.45). With the limited number of patients in mind, our findings tended towards an association between c-kit expression and survival in the LD group.
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PMID:Analysis of c-kit expression in small cell lung cancer: prevalence and prognostic implications. 1657 70

Despite recent developments in the diagnosis and conventional treatment of non small cell lung cancer (NSCLC), the prognosis remains unsatisfactory, with 5-year survival rates of approximately 15% for all stages. To date, chemotherapy represents the standard treatment for advanced-non small lung cancer, but efficacy of currently available cytotoxic drugs is modest. Median survival does not exceed 8-10 months. New treatment strategies are needed and considerable hope has been placed in therapies that specifically target the molecular mechanisms of tumour growth. One molecular target of particular relevance to lung cancer pathogenesis is the epidermal growth factor receptor (EGFR), a cell membrane receptor tyrosine kinase. Several inhibitors of EGFR fuctinonal activation have been developed. Amon these, erlotinib (Tarceva) and gefitinib (Iressa) are two orally bioavailable, small molecule EGFR inhibitors of the tyrosine kinase enzymatic activity which prevent EGFR autophosphorylation and activation. In monotherapy, gefitinib and erlotinib have determinated a 10-20% response rate and a 30-50% symptom improvement in previously treated, chemotherapy refractory, advanced NSCLC patients. Furthermore, a randomized, placebo controlled, multicenter phase III study has shown a two months improvement in median survival with erlotinib in the second or third line treatment of metastatic NSCLC patients. We will summarize the clinical evidence on the anticancer activity of small molecule EGFR inhibitors.
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PMID:Small molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer. 1660 81

Several peptide hormones have been identified which alter the proliferation of lung cancer. Small cell lung cancer (SCLC), which is a neuroendocrine cancer, produces and secretes gastrin releasing peptide (GRP), neurotensin (NT) and adrenomedullin (AM) as autocrine growth factors. GRP, NT and AM bind to G-protein coupled receptors causing phosphatidylinositol turnover or elevated cAMP in SCLC cells. Addition of GRP, NT or AM to SCLC cells causes altered expression of nuclear oncogenes, such as c-fos, and stimulation of growth. Antagonists have been developed for GRP, NT and AM receptors which function as cytostatic agents and inhibit SCLC growth. Growth factor antagonists, such as the NT1 receptor antagonist SR48692, facilitate the ability of chemotherapeutic drugs to kill lung cancer cells. It remains to be determined if GRP, NT and AM receptors will served as molecular targets, for development of new therapies for the treatment of SCLC patients. Non-small cell lung cancer (NSCLC) cells also have a high density of GRP, NT, AM and epidermal growth factor (EGF) receptors. Several NSCLC patients with EGF receptor mutations respond to gefitinib, a tyrosine kinase inhibitor. Gefitinib relieves NSCLC symptoms, maintaining stable disease in patients who are not eligible for systemic chemotherapy. It is important to develop new therapeutic approaches using translational research techniques for the treatment of lung cancer patients.
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PMID:Peptide hormones and lung cancer. 1663 28

Availability of KIT tyrosine kinase inhibitors for specific treatment of GISTs has magnified the importance of accurate differential diagnosis of GIST from other tumors occurring in the GI tract and abdomen. The general problems in this distinction include histological mimicry of other mesenchymal tumors with GIST, occasional KIT-negativity of GIST, and KIT-positivity of non-GISTs. Up to 5% to 10% gastric GISTs and <2% of intestinal GISTs can be KIT-negative. The identification of these tumors as GISTs is based on knowledge of the spectrum of GIST morphology, and can be supported by molecular diagnosis of KIT and PDGFRA mutations (the latter pertain to gastric tumors). True smooth muscle tumors (rare in GI tract except in esophagus and colon) can be separated from GISTs by the eosinophilic tinctorial quality of tumor cells, positivity for smooth muscle markers, and negativity for KIT. Desmoids can form large GIST-like masses, but are composed of spindled or stellate-shaped cells in a densely collagenous stroma. Negativity for KIT and nuclear positivity for beta-catenin are differentiating features. GI schwannomas, melanoma, and rare primary clear cell sarcoma are S100-positive, usually with characteristic histology. The latter two can be KIT-positive. KIT-positive non-GISTs include some sarcomas, especially angiosarcoma and Ewing sarcoma, extramedullary myeloid tumor, seminoma, and a few carcinomas, notably small cell carcinoma of lung. Spurious KIT-positivity, seen with some polyclonal KIT antibodies, has been a source of confusion leading to probable false-positive results in fibroblastic tumors and occasional other sarcomas, such as leiomyosarcomas. Integration of histological features with carefully standardized immunohistochemistry, supported by KIT and PDGFRA mutation analysis, is the cornerstone of state-of-the art differential diagnosis of GIST. To comprehensively capture all GISTs, KIT immunostains should be performed on all unclassified epithelioid and mesenchymal tumors of the abdomen. This is a US government work. There are no restrictions on its use.
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PMID:Gastrointestinal stromal tumors: differential diagnosis. 1719 24

Non small cell lung cancer (NSCLC) is a major health public issue because of its frequency and related mortality. Progress with chemotherapy in advanced NSCLC has reached a plateau and more effective and better tolerated therapeutic strategies are needed. Epidermal growth factor receptor (EGFR) is overexpressed in 80% of NSCLC and inhibitors of EGFR tyrosine kinase have now an important place in the management of NSCLC. Most significant results have been obtained with oral inhibitors like erlotinib or gefitinib. Erlotinib role in second and third line setting is firmly established. Recent data suggests that in the first line setting, interesting overall response rates improving survivals can be obtained, in specific subpopulations defined either by histology (adenocarcinomas, adenocarcinomas with bronchioloalveolar features), sex (women), non-smoking status (never-smokers) or biological markers (tumours with EGFR mutations in exons 18-21). Such improvements are especially valuable because inhibitors of EGFR tyrosine kinase are better tolerated than chemotherapy. The exact contribution of monoclonal antibodies like cetuximab is still unclear in NSCLC.
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PMID:[Inhibitors of the EGFR pathway in non small cell lung cancer: what's new in 2007?]. 1723 5

Small cell lung cancer (SCLC) is a difficult disease to treat and sometimes has overexpression or mutation of c-Met receptor tyrosine kinase. The effects of c-Met/hepatocyte growth factor (c-Met/HGF, ligand for c-Met) on activation of reactive oxygen species (ROS) was determined. HGF stimulation of c-Met-overexpressing H69 SCLC cells (40 ng/ml, 15 min) resulted in an increase of ROS, measured with fluorescent probe 2'-7'-dichlorofluorescein diacetate (DCFH-DA) or dihydroethidine (DHE) but not in c-Met-null H446 cells. ROS was increased in juxtamembrane (JM)-mutated variants (R988C and T1010I) of c-Met compared with wild-type c-Met-expressing cells. ROS was significantly inhibited by preincubation of SCLC cells with pyrrolidine dithiocarbamate (PDTC, 100 microM) and/or SU11274 (small molecule c-Met tyrosine kinase inhibitor, 2 microM) for 3 h. PDTC and SU11274 also abrogated the HGF proliferative signal and cell motility in a cooperative fashion. H(2)O(2) treatment of SCLC cells (over 15 min) led to phosphorylation of c-Met receptor tyrosine kinase and further upregulated downstream phosphorylation of phospho-AKT, ERK1/2, and paxillin in a dose-dependent manner (125 microM to 500 microM). c-Met is an important target in lung cancer, and the pathways responsible for ROS generation together may provide novel therapeutic intervention.
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PMID:Activation of HGF/c-Met pathway contributes to the reactive oxygen species generation and motility of small cell lung cancer cells. 1732 84

Therapies targeted on cell signal pathways that control cell division and tumor angiogenesis have been developed over the last five years for non small cell lung cancer (NSCLC) with some amazing results, in subgroups of selected patients, predicting more significant success in the upcoming years. Compounds targeted on EGF tyrosine kinase receptor have been tested in large clinical phase 2 and 3 trials including thousands of patients. Their efficacy has been proved, in second and third line trials, after first line cisplatin-based chemotherapy for non-mucinous adenocarcinoma in non-smokers, women and Asian patients. Response rates vary from 10% in non selected Caucasian patients to 40% in non-smoking Asian patients with long survivals. Therapeutic targeting improves success rates, either relying on EGFR gene amplification detection by FISH, or search for EGFR tyrosine kinase domain mutations. Commercial kits are available for routine molecular diagnosis of domain mutations potentially enabling molecular targeting in addition to clinical targeting. Angiogenesis inhibitors, especially monoclonal antibody to VEGF, bevacizumab, have also been developed in the last few years. Bevacizumab associated with classical cytotoxic chemotherapy led, in selected patients (with non squamous cell lung cancer and no past history of cardiovascular disease) to an increase of median survival to more than 12 months with tolerable toxicity. Other drugs that have both anti-EGFR activity and anti-angiogenic properties will be soon developed, since future bioactive anti-cancer drugs will probably be multi-targeted drugs.
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PMID:[New biological treatments for lung cancer]. 1745 80

In lung cancer, frequent loss of one allele of chromosome 3p is seen in both small cell lung cancer and non-small cell lung cancer (NSCLC), providing evidence of tumor suppressor genes (TSGs) in this chromosomal region. The mechanism of Fus1 tumor suppressor activity is unknown. We have found that a Fus1 peptide inhibits the Abl tyrosine kinase in vitro (IC(50) 35 microM). The inhibitory Fus1 sequence was derived from a region that was deleted in a mutant FUS1 gene (FUS1 (1-80)) detected in some lung cancer cell lines. Importantly, a stearic acid-modified form of this peptide was required for the inhibition, but stearic acid alone was not inhibitory. Two NSCLC cell lines, which lack expression of wild-type Fus1, contain activated c-Abl. Forced expression of an inducible FUS1 cDNA in H1299 NSCLC cells decreased levels of activated c-Abl and inhibited its tyrosine kinase activity. Similarly, treatment of c-Abl immune complexes with the inhibitory Fus1 peptide also reduced the level of c-Abl in these immune complexes. The size and number of colonies of the NSCLC cell line, H1,299, in soft agar was strongly inhibited by the Abl kinase inhibitor imatinib mesylate. Co-expression of FUS1 and c-ABL in COS1 cells blocked activation of c-Abl tyrosine kinase. In contrast, co-expression of mutant FUS1 (1-80) with c-ABL had little inhibitory activity against c-Abl. These findings provide strong evidence that c-Abl is a possible target in NSCLC patients that have reduced expression of Fus1 in their tumor cells.
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PMID:Oncogenic activation of c-Abl in non-small cell lung cancer cells lacking FUS1 expression: inhibition of c-Abl by the tumor suppressor gene product Fus1. 1748 70


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