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:C0684249 (lung carcinoma)
23,830 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genes of the RAF family, which mediate cellular responses to growth signals, encode kinases that are regulated by RAS and participate in the RAS, RAF, mitogen/extracellular signal-regulated kinase, extracellular signal-regulated kinase and mitogen-activated protein kinase pathway. As BRAF is a serine/threonine kinase that is commonly activated by somatic point mutation, it may provide possible diagnostic and therapeutic targets in human malignant tumors. We analyzed exon 15 of the BRAF gene for mutations in 58 lung, 12 breast, six kidney, 14 cervical, four endometrial and 10 ovarian carcinoma cell lines by PCR-SSCP and direct sequencing. The T1796A transversion was found in one (2.9%) of 34 small cell lung carcinoma and one (8.3%) of 12 breast carcinoma cell lines, resulting in a valine-to-glutamate substitution at residue 599 (V599E). One (4.2%) of 24 non-small cell lung carcinoma cell line showed the C1786G transversion, leading to a leucine-to-valine substitution at residue 596 (L596V). No BRAF point mutations were found in any of the other cell lines examined. Our present results suggest that BRAF may not be a frequent target of mutations involved in the pathogenesis of human lung, breast, kidney, cervical, endometrial and ovarian carcinomas.
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PMID:Mutational analysis of the BRAF gene in human tumor cells. 1839 70

Erythropoietin (Epo), a known hematopoietic growth factor, has been reported to promote tumor growth and angiogenesis in Epo receptor (EpoR)-positive tumors, but its effects on EpoR-negative tumors have not been clearly shown. Here, we show that Epo accelerates the growth of EpoR-negative tumors by promoting tumor angiogenesis. Mice were inoculated with Lewis lung carcinoma cells and treated with Epo. Erythropoietin accelerated tumor growth and increased intratumoral microvessel density, although it did not accelerate Lewis lung carcinoma cell tumor proliferation in vitro. To observe the direct effect of Epo on endothelial cells, we examined human dermal microvascular endothelial cells (HMVECs) that expressed EpoR. Erythropoietin induced the proliferation of HMVECs and protected them from H2O2-induced cell death. Erythropoietin activated the extracellular signal-regulated kinase signaling pathway and up-regulated the expression of the downstream antiapoptotic protein Bcl-xL in HMVECs. Moreover, in both the absence and presence of tumors, in vivo treatment of mice with Epo increased circulating endothelial progenitor cells. To investigate the role of Epo in a primary tumor model, we inoculated the chemical carcinogen methylcholanthrene (MCA) subcutaneously into mice at two doses, a high or a low dose, which induced fibrosarcoma, and treated them with Epo. Erythropoietin promoted tumor growth after MCA inoculation at both doses and decreased the overall survival of the mice inoculated with the high-dose MCA. However, Epo did not increase the incidence of fibrosarcoma at either dose. Lewis lung carcinoma cells and MCA-induced fibrosarcomas did not express EpoR. These results suggest that Epo accelerates the growth of tumors that lack EpoR expression by promoting tumor angiogenesis.
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PMID:Erythropoietin promotes the growth of tumors lacking its receptor and decreases survival of tumor-bearing mice by enhancing angiogenesis. 1871 93

We and others have shown previously that nicotine, a major component of tobacco, stimulates non-small cell lung carcinoma (NSCLC) proliferation through nicotinic acetylcholine receptor (nAChR)-mediated signals. Activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to inhibit NSCLC cell growth, but the exact mechanisms responsible for this effect remain incompletely defined. Herein, we show that nicotine induces NSCLC cell proliferation in part through alpha4 nAChR, prompting us to explore the effects of rosiglitazone, a synthetic PPARgamma ligand, on the expression of this receptor. Rosiglitazone inhibited the expression of alpha4 nAChR, but this effect was through a PPARgamma-independent pathway, because GW9662, an antagonist of PPARgamma, and the transfection of cells with PPARgamma small interfering RNA failed to abolish the response. The inhibitory effect of rosiglitazone on alpha4 nAChR expression was accompanied by phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2 and down-regulation of Akt phosphorylation. These signals mediated the inhibitory effects of rosiglitazone on alpha4 nAChR expression because chemical inhibitors prevented the effect. Rosiglitazone was also found to stimulate p53, a tumor suppressor known to mediate some of the effects of nicotine. Interestingly, p53 up-regulation was needed for rosiglitazone-induced inhibition of alpha4 nAChR. Thus, rosiglitazone inhibits alpha4 nAChR expression in NSCLC cells through activation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase, which triggers induction of p53. Finally, like others, we found that nicotine stimulated the expression of alpha4 nAChR. This process was also inhibited by rosiglitazone through similar pathways.
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PMID:Rosiglitazone inhibits alpha4 nicotinic acetylcholine receptor expression in human lung carcinoma cells through peroxisome proliferator-activated receptor gamma-independent signals. 1913 19

We previously showed that synthetic peroxisome proliferator-activated receptor gamma (PPARgamma) ligands inhibit non-small cell lung carcinoma (NSCLC) cell growth through multiple signaling pathways. Here, we show that dietary compounds, such as fish oil (which contains certain kinds of fatty acids like omega3 and omega6 polyunsaturated fatty acids), also inhibit NSCLC cell growth by affecting PPARgamma and by inhibiting the expression of integrin-linked kinase (ILK). Exogenous expression of ILK overcame, whereas silencing ILK enhanced the inhibitory effect of fish oil on cell growth. The inhibitor of p38 mitogen-activated protein kinase, SB239023, abrogated the inhibitory effect of fish oil on ILK expression, whereas the inhibitor of extracellular signal-regulated kinase, PD98059, had no effect. Transient transfection experiments showed that fish oil reduced ILK promoter activity, and this effect was abolished by AP-2alpha small interfering RNA and SB239023 and by deletion of a specific portion of the ILK gene promoter. Western blot analysis and gel mobility shift assay showed that fish oil significantly induced AP-2alpha protein expression and AP-2 DNA-binding activity in the ILK gene promoter and that this was dependent on PPARgamma activation. Blockade of AP-2alpha abrogated the effect of fish oil on ILK expression and on cell growth, whereas exogenous expression of AP-2alpha enhanced cell growth in the setting of fish oil exposure. Taken together, these findings show that fish oil inhibits ILK expression through activation of PPARgamma-mediated and p38 mitogen-activated protein kinase-mediated induction of AP-2alpha. In turn, this leads to inhibition of NSCLC cell proliferation. This study unveils a novel mechanism by which fish oil inhibits human lung cancer cell growth.
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PMID:Fish oil inhibits human lung carcinoma cell growth by suppressing integrin-linked kinase. 1914 42

Cyclooxygenase-2-derived prostaglandin E(2) (PGE(2)) stimulates tumor cell growth and progression. However, the mechanisms by which PGE(2) increases tumor growth remain incompletely understood. In studies performed in non-small cell lung carcinoma (NSCLC) cells, we found that PGE(2) stimulates the expression of integrin-linked kinase (ILK). ILK small interfering RNA (siRNA) inhibited the mitogenic effects of PGE(2). In view of its perceived importance, we turned our attention to the mechanisms involved in PGE(2)-induced ILK expression and found that this effect was blocked by an antagonist of the PGE(2) receptor subtype EP4 and by EP4 siRNA. Furthermore, we showed that PGE(2) induction of ILK was associated with phosphorylation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase/Akt, which were abrogated by ILK siRNA. Transient transfection, gel mobility shift assays, and chromatin immunoprecipitation experiments showed that PGE(2) induced ILK promoter activity and increased Sp1, although it had no effect on nuclear factor-kappaB and AP-2 DNA-binding activity. Blockade of Sp1 abrogated the effect of PGE(2) on expression of ILK and promoter activity and on cell growth. In summary, our observations show that PGE(2) increases NSCLC cell growth through increased ILK expression, which is dependent on EP4 signaling and on induction of Sp1 protein and Sp1 DNA-binding activity in the ILK promoter. These studies suggest a novel molecular mechanism by which PGE(2) stimulates NSCLC cell growth and unveils a new molecular target for the development of therapies against NSCLC.
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PMID:Prostaglandin E2 stimulates human lung carcinoma cell growth through induction of integrin-linked kinase: the involvement of EP4 and Sp1. 1917 80

Shikonin and beta-hydroxyisovalerylshikonin (beta-HIVS) from Lithospermum erythrorhizon inhibit angiogenesis via inhibition of vascular endothelial growth factor receptors (VEGFR) in an adenosine triphosphate-non-competitive manner, although the underlying molecular mechanism has not been fully understood. In the present study, we found that beta-HIVS inhibited angiogenesis within chicken chorioallantoic membrane approximately threefold more efficiently than shikonin. beta-HIVS also significantly inhibited angiogenesis in two other assays, induced either by Lewis lung carcinoma cells implanted in mouse dorsal skin or by VEGF in s.c. implanted Matrigel plugs and metastasis of Lewis lung carcinoma cells to lung. Therefore, using beta-HIVS as a bioprobe, we investigated the molecular mechanism of shikonin's anti-angiogenic actions. beta-HIVS inhibited the phosphorylation and expression of VEGFR2 and Tie2 without affecting VEGFR1 and fibroblast growth factor receptor 1 levels. beta-HIVS suppressed the phosphorylation but not the expression of extracellular signal-regulated kinase, and an Sp1-dependent transactivation of the VEGFR2 and Tie2 promoters, thereby suppressing the proliferation of vascular endothelial and progenitor cells. This was mimicked by an Sp1 inhibitor mithramycin A and partially rescued by Sp1 overexpression. These results implicate potential use of shikonin and beta-HIVS as leading compounds for clinical application in the future by virtue of their unique properties including: (i) inhibition of VEGFR2 and Tie2 phosphorylation in an adenosine triphosphate-non-competitive manner; (ii) simultaneous inhibition of the phosphorylation and expression of VEGFR2 and Tie2; and (iii) bifunctional inhibition of the growth in endothelial cells and vascular remodeling.
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PMID:Mechanism of inhibition of tumor angiogenesis by beta-hydroxyisovalerylshikonin. 1920 Feb 58

Tetrandrine (TET), a bis-benzylisoquinoline alkaloid from the root of Stephania tetrandra, is known to have anti-tumor activity in various malignant neoplasms. However, the precise mechanism by which TET inhibits tumor cell growth remains to be elucidated. The present studies were performed to characterize the potential effects of TET on phosphoinositide 3-kinase/Akt and extracellular signal-regulated kinase (ERK) pathways since these signaling pathways are known to be responsible for cell growth and survival. TET suppressed cell proliferation and induced apoptosis in A549 human lung carcinoma cells. TET treatment resulted in a down-regulation of Akt and ERK phosphorylation in both time-/concentration-dependent manners. The inhibition of ERK using PD98059 synergistically enhanced the TET-induced apoptosis of A549 cells whereas the inhibition of Akt using LY294002 had a less significant effect. Taken together, our results suggest that TET: i) selectively inhibits the proliferation of lung cancer cells by blocking Akt activation and ii) increases apoptosis by inhibiting ERK. The treatment of lung cancers with TET may enhance the efficacy of chemotherapy and radiotherapy and increase the apoptotic potential of lung cancer cells.
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PMID:Synergistic effect of ERK inhibition on tetrandrine-induced apoptosis in A549 human lung carcinoma cells. 1925 20

The role of thromboxane receptor alpha (TPalpha) in tumor growth and angiogenesis was investigated in a nude mice model and in cell culture. Stable human lung cancer A549 cells over-expressing TPalpha (A549-TPalpha) was generated and used to inoculate athymic nude mice. A549-TPalpha cells induced greater tumor growth and increased vascularization in tumors than in the control A549 cells. Increased angiogenesis was further verified by studying the induction of vascular endothelial growth factor (VEGF) in A549-TPalpha cells. I-BOP, an agonist of TP, stimulated the expression of VEGF in this cell line as well as in another human lung cancer H157 cells in a time and dose dependent manner. The expression of VEGF was determined at both the mRNA and protein levels. The signaling pathways that are involved in I-BOP-induced VEGF expression were further examined by the use of inhibitors. Inhibition of the extracellular signal-regulated kinase (ERK) activation blocked the induction almost completely indicating that ERK activation was an essential step in the induction. Each of the three upstream kinases, protein kinase A, EGFR kinase and Src kinase, contributed partially to the overall induction. However, PI 3-kinase and protein kinase C had minimal contribution. These results indicate that activation of the TPalpha induces the expression of VEGF through multiple signaling pathways.
Lung Cancer 2010 Jul
PMID:Thromboxane receptor alpha mediates tumor growth and angiogenesis via induction of vascular endothelial growth factor expression in human lung cancer cells. 1985 59

Anthocyanins, present in various vegetables and fruits as a nature colorant, have broad activities including anticarcinogenesis and antimutagenesis, which are generally attributed to their antioxidant activities. However, limited studies have been available concerning the inhibitory effect of peonidin 3-glucoside (P3G) for cancer metastasis. Here, we demonstrated that P3G could significantly inhibit the invasion (P < 0.001), motility (P < 0.05), secretion of matrix metalloproteinase (MMP)-2, MMP-9, and urokinase-type plasminogen activator (u-PA) of lung cancer cells. Meanwhile, P3G attenuated phosphorylation of extracellular signal-regulated kinase (ERK)1/2, a member of mitogen-activated protein kinase (MAPK) family involved in the upregulation of MMPs and u-PA, and also inhibited the activation of activating protein-1 (AP-1) as shown by Western blot and electrophoretic mobility shift assay. Thus, the inhibitory effects of P3G may be at least partly through inactivation of ERK 1/2 and AP-1 signaling pathways as confirmed by abolishment of P3G-inhibited H1299 cell invasion by overexpression of MAPK kinase 1 (MEK1). Finally, P3G was evidenced by its inhibition on the metastasis of Lewis lung carcinoma cells in vivo (P < 0.001). Taken together, these findings suggested that P3G could reduce the metastasis of lung cancer cells, thereby constituting an adjuvant treatment for metastasis control.
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PMID:Peonidin 3-glucoside inhibits lung cancer metastasis by downregulation of proteinases activities and MAPK pathway. 2043 72

The mechanisms underlying the proapoptotic effect of the chemotherapeutic agent, cisplatin, are largely undefined. Understanding the mechanisms regulating cisplatin cytotoxicity may uncover strategies to enhance the efficacy of this important therapeutic agent. This study evaluates the role of activating transcription factor 3 (ATF3) as a mediator of cisplatin-induced cytotoxicity. Cytotoxic doses of cisplatin and carboplatin treatments consistently induced ATF3 expression in five tumor-derived cell lines. Characterization of this induction revealed a p53, BRCA1, and integrated stress response-independent mechanism, all previously implicated in stress-mediated ATF3 induction. Analysis of mitogen-activated protein kinase (MAPK) pathway involvement in ATF3 induction by cisplatin revealed a MAPK-dependent mechanism. Cisplatin treatment combined with specific inhibitors to each MAPK pathway (c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38) resulted in decreased ATF3 induction at the protein level. MAPK pathway inhibition led to decreased ATF3 messenger RNA expression and reduced cytotoxic effects of cisplatin as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay. In A549 lung carcinoma cells, targeting ATF3 with specific small hairpin RNA also attenuated the cytotoxic effects of cisplatin. Similarly, ATF3-/- murine embryonic fibroblasts (MEFs) were shown to be less sensitive to cisplatin-induced cytotoxicity compared with ATF3+/+ MEFs. This study identifies cisplatin as a MAPK pathway-dependent inducer of ATF3, whose expression influences cisplatin's cytotoxic effects.
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PMID:Cisplatin induces cytotoxicity through the mitogen-activated protein kinase pathways and activating transcription factor 3. 2065 82


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