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)

One of the functions of adenomatous polyposis coli (APC) in colorectal cancers is regulation of c-myc gene expression. However, the role of APC in lung cancers has not been elucidated. In the present study, the levels of APC and c-myc mRNA were determined in one strain of normal human bronchial epithelial (NHBE) cells, an SV-40-immortalized non-tumorigenic human bronchial epithelial cell line (BEAS-2B), 13 non-small cell lung cancer cell lines, and 4 small cell lung cancer cell lines. To establish a relationship between c-Myc and APC, we determined the ratio of c-myc and APC mRNA levels in different lung cancer cell lines. Out of 19 lung cancer cell lines, we found that 13 exhibited c-myc/APC mRNA ratio of more than two. Among the cell lines CaLu-3, NCI-H82, A427 and SW900 showed a very low level of APC mRNA and a high level of c-myc mRNA. The ratio of c-myc/APC mRNA in these cell lines was 48, 127, 325 and 708, respectively. The results of these analyses revealed an inverse relationship between APC and c-myc mRNA levels, suggesting that APC may regulate c-myc expression in lung cancer cells in a manner analogous to its role in colon cancer.
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PMID:A correlation of APC and c-myc mRNA levels in lung cancer cell lines. 1052 91

The c-myc oncogene is frequently amplified in cells grown from lung tumors and has been linked to the malignancy of these cancers. In support of this, c-myc transfection enhances the in vitro proliferation and soft agar cloning of human small cell lung cancer (SCLC) cells. In this study, we surprisingly found that c-myc expression suppressed the formation of tumors by SCLC cells in athymic nude mice. c-myc expression down-regulated the protein and transcript for vascular endothelial growth factor (VEGF) in these SCLC cells, as well as VEGF transcript in rat fibroblasts manipulated for c-myc expression and in liver cells of c-myc-transgenic mice. Finally, bivariate and multivariate analyses demonstrated that the probability of tumor formation from lung cancer cell lines was negatively correlated with the relative expression of c-Myc, positively correlated with the relative expression of VEGF, and that the latent time to tumor formation was increased by the expression of c-Myc and decreased by the expression of VEGF. We hypothesize that, for lung cancer cells, c-Myc suppresses the formation of tumors in vivo by down-regulating VEGF, and that the amplification of c-myc seen in cells grown from lung tumors with a poor prognosis is an artifact of selection for growth in vitro.
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PMID:c-Myc suppresses the tumorigenicity of lung cancer cells and down-regulates vascular endothelial growth factor expression. 1064 66

In the present review recent data regarding the role of integrins--an important category of adhesion molecules mediating interactions among cells and components of the extracellular matrix--in lung cancer development is discussed. Investigations have shown that down-regulation of alpha3 integrin subunit may contribute to enhanced tumorigenicity of c-myc-overexpressing small cell lung carcinoma, while the loss of an integrin expression is correlated with recurrence in node-negative lung carcinoma. Increased expression of alpha1beta1 and alpha2beta1 integrins have been shown to be positively correlated with increased metastatic ability in squamous cell carcinoma. alpha3beta1 integrin is a most critical integrin for pulmonary development and epithelium integrity and its reduced expression in small cell lung cancer is probably related to the increased aggressiveness of this type. Pulmonary cancer cells generally express fewer integrin receptors than the normal epithelium. Additionally, since the ability of malignant cells to interact with extracellular matrix components is thought to be important, integrin dependent migration of lung cancer cells is a crucial process.
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PMID:Integrin receptors in primary lung cancer. 1527 61

Nitrosamines are carcinogens formed in the mammalian organism from amine precursors contained in food, beverages, cosmetics and drugs. The potent carcinogen, NNK, and the weaker carcinogen, NNN, are nitrosamines formed from nicotine. Metabolites of the nitrosamines react with DNA to form adducts responsible for genotoxic effects. We have identified NNK as a high affinity agonist for the alpha7 nicotinic acetylcholine receptor (alpha7nAChR) whereas NNN bound with high affinity to epibatidine-sensitive nAChRs. Diethylnitrosamine (DEN) bound to both receptors but with lower affinity. High levels of the alpha7nAChR were expressed in human small cell lung cancer (SCLC) cell lines and in hamster pulmonary neuroendocrine cells (PNECs), which serve as a model for the cell of origin of human SCLC. Exposure of SCLC or PNECs to NNK or nicotine increased expression of the alpha7nAChR and caused influx of Ca(2+), activation of PKC, Raf-1, ERK1/2, and c-myc, resulting in the stimulation of cell proliferation. Signaling via the alpha7nAChR was enhanced when cells were maintained in an environment of 10-15% CO(2) similar to that in the diseased lung. Hamsters with hyperoxia-induced pulmonary fibrosis developed neuroendocrine lung carcinomas similar to human SCLC when treated with NNK, DEN, or nicotine. The development of the NNK-induced tumors was prevented by green tea or theophylline. The beta-adrenergic receptor agonist, isoproterenol or theophylline blocked NNK-induced cell proliferation in vitro. NNK and nicotine-induced hyperactivity of the alpha7nAChR/RAF/ERK1/2 pathway thus appears to play a crucial role in the development of SCLC in smokers and could be targeted for cancer prevention.
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PMID:Nitrosamines as nicotinic receptor ligands. 1745 20

A number of genes display altered activity in human small cell lung cancer (SCLC), in particular members of the myc family (c-myc, L-myc, N-myc) that frequently are expressed at high levels. GLC4, a cell line established at the State University of Groningen from a SCLC, contains a 30 fold amplified c-myc gene and the cells show a high steady state c-myc transcription rate. The amplified c-myc copies of this cell line are not grossly rearranged and contain the gene's known major EcoRI (12 kb) fragment. To investigate in detail the mechanism(s) responsible for transcriptional activation we analyzed the c-myc promoter region. Whereas point mutations, which often occur in a mutational hot spot region in Burkitt's lymphoma, were not detected, c-myc transcription in GLC4 initiates mainly from P1 instead of the P2 promoter. This promoter shift seems to overcome transcript termination at a transcriptional pause site described for Burkitt's lymphoma c-myc sequence. Our data suggest that the shift of promoter usage - together with gene amplification - plays a likely role in c-myc transcriptional activation in GLC4 SCLC cells.
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PMID:Constitutive C-myc overexpression and p1/p2 promoter shift in a small-cell lung-cancer cell-line. 2155 58

The analysis of oncogene expression may provide insights into the pathogenesis of small cell lung cancer (SCLC) and may help to predict clinical behavior. The expression of 8 oncogenes (c-myc, N-myc, L-myc, Ha-ras, Ki-ras, N-ras, erbB-2, v-sis) was evaluated in small cell lung cancer (SCLC) xenografts of tumor samples, recentlly transplanted, taken from 17 different patients. Eight of these 17 SCLC lines expressed the L-myc oncogene and 2 SCLC lines expressed the c-myc oncogene. One SCLC line (SCLC-63M) simultaneously expressed the L-myc and c-myc oncogenes. All SCLC lines examined had almost similar high RNA levels of the Ki-ras oncogene, while the expression of Ha- and N-ras oncogenes was not always observed. The N-myc and v-sis oncogenes were expressed in only one tumor and at a very weak level, and no transcript of the erbB-2 oncogene was observed in any of our 17 SCLC lines. These results indicate that oncogene expression in SCLC lines is heterogeneous, with the exception of the Ki-ras oncogene which is constantly overexpressed.
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PMID:Heterogeneous expression of oncogenes in small-cell lung-cancer xenografts. 2157 1

It has been reported that CREPT acts as a highly expressed oncogene in a variety of tumors, affecting cyclin D1 signal pathways. However, the distribution and clinical significance of CREPT in NSCLC remains poorly understood. Our study focused on the role of CREPT on the regulation ofnon-small cell lung cancer (NSCLC). We found that CREPT mRNA and protein expression was significantly increased in NSCLC compared with adjacent lung tissues and was increased in various NSCLC cell lines compared with the normal human bronchial epithelial (HBE) cell line. siRNA-induced knockingdown of CREPT significantly inhibited the proliferation and migration of NSCLC cell lines by arresting cell cycle in S phase. Moreover, CREPT knocking down affected the expression of cell cycle proteins including c-mycand CDC25A. Finally, we found there were obvious correlations between CREPT with c-myc expression in histological type, differentiation, and pTNM stages of NSCLC (P<0.05, rs>0.3). Immunohistofluorescence studies demonstrated a co-localization phenomenon when CREPT and c-myc were expressed. Thus, we propose that CREPT may promote NSCLC cell growth and migration through the c-myc and CDC25A signaling molecules.
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PMID:Inhibiting CREPT reduces the proliferation and migration of non-small cell lung cancer cells by down-regulating cell cycle related protein. 2734 18


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