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

Mammalian pancreatic ribonuclease (RNase) was conjugated chemically via a disulfide bond to human or murine epidermal growth factor (EGF). The conjugation between EGF and RNase was ascertained by SDS-PAGE using reduced and nonreduced conjugates. The EGF-RNase conjugate retained potent RNase activity and competed with 125I-EGF for binding to EGFR to the same extent as unconjugated EGF. Both the human and murine EGF-RNase conjugates showed dose-dependent cytotoxicity against EGFR-overexpressing A431 human squamous carcinoma cells with IC50 values of 3 x 10(-7) M and 6 x 10(-7) M, respectively, whereas free RNase had an IC50 of 10(-4) M. Against the EGFR-deficient small-cell lung cancer cell line H69, the EGF-RNase conjugate had no cytotoxic effect. The Human EGF-RNase conjugate showed dose-dependent cytotoxicity against other squamous carcinoma cell lines (TE-5, TE-1) and breast cancer cell lines (BT-20, SK-BR-3, MCF-7) and the cytotoxicity of the conjugate correlated positively with the level of expression of EGFR by each cell line. An unconjugated mixture of EGF and RNase had no greater effect than RNase alone on any cell line. Excess free EGF blocked EGF-RNase conjugate cytotoxicity against A431 cells. These results suggest that the EGF-RNase conjugate may be a more effective anticancer agent with less immunogenicity than coventional chimeric toxins.
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PMID:Epidermal growth factor receptor-dependent cytotoxic effect by an EGF-ribonuclease conjugate on human cancer cell lines--a trial for less immunogenic chimeric toxin. 867 51

We sought evidence that pulmonary carcinomas mediate a cellular immunologic response by analyzing T-cell antigen receptor beta-chain variable gene (TCRBV) repertoires of lymphocytes from peripheral blood (PBL) and malignant pleural effusions (PEL) of five lung cancer patients. Expression levels of 27 TCRBV were quantitated by multiprobe RNase protection assay (RPA), and clonal expansions were identified by sequence enrichment nuclease assay (SENA) and junctional region sequencing. Abnormal TCRBV expansions were identified in all subjects by RPA (mean 6.9 +/- 1.7/patient), and their number closely correlated with elapsed time since initial diagnosis (r = 0.97). SENA, performed in specimens from three patients, confirmed the presence of mono or oligoclonality in 48% of abnormal RPA expansions, and further identified T-cell clones among TCRBV with normal expression levels. The majority of clonal expansions were among PEL, and were nearly equally divided between CD4 and CD8. These data show that T-cell repertoires of lung cancer patients are characterized by marked abnormalities and frequent clonal expansions, most likely representing responses to unique, tumor-specific antigens (TSA). Moreover, this process appears exaggerated among PEL, further suggesting that malignant effusions include local proliferations of tumor reactive T cells. These findings imply the presence of lung cancer TSA capable of eliciting cellular immune responses and raise the possibility that selective immunotherapies can ultimately be developed.
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PMID:T-cell receptor biases and clonal proliferations in blood and pleural effusions of patients with lung cancer. 912 46

The receptor tyrosine kinase c-kit is necessary for normal hematopoiesis, the development of germ cells and melanocytes, and the pathogenesis of certain hematologic and nonhematologic malignancies. To better understand the regulation of the c-kit gene, a detailed analysis of the core promoter was performed. Rapid amplification of cDNA ends (RACE) and RNase protection methods showed two major transcriptional initiation sites. Luciferase reporter assays using 5' promoter deletion-reporter constructs containing up to 3 kb of 5' sequence were performed in hematopoietic and small-cell lung cancer cell lines which either did or did not express the endogenous c-kit gene. This analysis showed the region 83 to 124 bp upstream of the 5' transcription initiation site was crucial for maximal core promoter activity. Sequence analysis showed several potential Sp1 binding sites within this highly GC-rich region. Gel shift and DNase footprinting showed that Sp1 selectively bound to a single site within this region. Supershift studies using an anti-Sp1 antibody confirmed specific Sp1 binding. Site-directed mutagenesis of the -93/-84 Sp1 binding site reduced promoter-reporter activity to basal levels in c-kit-expressing cells. Cotransfection into Drosophila SL2 cells of a c-kit promoter-reporter construct with an Sp1 expression vector showed an Sp1 dose-dependent enhancement of expression that was markedly attenuated by mutation of the -93/-84 site. These results indicate that despite the fact that the human c-kit promoter contains multiple potential Sp1 sites, Sp1 binding is a selective process that is essential for core promoter activity.
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PMID:Selective Sp1 binding is critical for maximal activity of the human c-kit promoter. 983 19

The murine anti-bombesin monoclonal antibody, 2A11, has been demonstrated to inhibit growth of some small-cell lung cancer (SCLC) cells in nude mice xenografts and in a clinical trial. To determine if the expression of bombesin-like peptides (BLP) and their receptors (GRP-R and NMB-R) correlate with an in vitro response to 2A11, we measured these parameters in seven SCLC cell lines. Gastrin releasing peptide (GRP) mRNA was detected in three of seven cell lines (NCI-H69, NCI-H345, NCI-H510) and neuromedin B (NMB) mRNA was detected in all seven lines using an RNase protection assay (RPA). Immunoreactive BLP was detected in the cell pellets of all lines (range 0.11-59.90 pmol/mg protein) by a solid phase GRP radioimmunoassay (RIA) using 125I-labeled 2A11. RPA detected GRP-receptor mRNA in two cell lines (NCI-H69 and NCI-H345) and NMB-receptor in three lines (NCI-H345, NCI-H510, and NCI-H660). Reverse transcriptase-PCR confirmed the presence of receptor mRNA in these lines and detected NMB-receptor in an additional three lines (NCI-H69, NCI-H82, and NCI-H187). Calcium mobilization in response to BLP stimulation was detected in the six cell lines expressing either GRP-R or NMB-R mRNA but not in NCI-N417, which had no detectable BLP-receptor. 2A11 (5 microg/ml) inhibited colony formation by 26-61% after 2 weeks in all cell lines except NCI-N417. Thus, growth inhibition by 2A11 requires the presence of at least one BLP-receptor. These findings may be useful in selecting patients with SCLC for treatment with 2A11.
Lung Cancer 1998 Sep
PMID:Correlation of expression of bombesin-like peptides and receptors with growth inhibition by an anti-bombesin antibody in small-cell lung cancer cell lines. 985 94

Expression of several molecular determinants of apoptosis was analyzed in 10 untreated small cell (SCLC) and 6 untreated non-small cell (NSCLC) lung carcinoma cell lines. Although SCLC lines were more prone to spontaneous apoptosis compared with NSCLC lines, the former showed higher Bcl-2 expression and a higher Bcl-2/Bax ratio. In order to understand this apparent contradiction, the expression of pro-caspases as well as calpain was analyzed in these cell lines at the protein and mRNA levels. No differences in protein level of pro-caspases-2, -3, -7, and -9 and of calpain were detected between the SCLC and the NSCLC lines, but a striking difference in pro-caspase-8 expression was noted. All 6 NSCLC, but only 2 of the 10 SCLC lines, expressed pro-caspase-8 protein. Further experiments using the RNase protection assay indicated that the lack of pro-caspase-8 expression at the mRNA level was characteristic for SCLC. Using the same experimental approach, we found that SCLC cell lines in addition to pro-caspase-8 were deficient in mRNA expression of pro-caspases-1, -4, and -10, suggesting a different caspase-activating cascade in SCLC compared with NSCLC. This first systematic characterization of pro-caspase expression in lung cancer surprisingly showed that SCLC, which are more prone to undergo spontaneous apoptosis, are deficient in several pro-caspases and have a high Bcl-2/Bax ratio. Thus, the propensity of SCLC cells to undergo apoptosis cannot be explained only by the expression of factors involved in regulation or execution of apoptosis.
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PMID:Differences in expression of pro-caspases in small cell and non-small cell lung carcinoma. 1046 84

We have conjugated the murine monoclonal antibody (528) against the human epidermal growth factor receptor (EGFR) to mammalian pancreatic ribonuclease (RNase) via N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP) and 2-iminothiolene (2-IT). The conjugate showed dose-dependent cytotoxicity against EGFR-producing squamous cancer cells (A431, TE8, TE5, Ca9-22) and no detectable cytotoxicity against EGFR-deficient small-cell lung cancer cells (H69). The cytotoxicity of the conjugate was positively correlated with the EGFR numbers of each cell line. The addition of excess 528 antibody to the medium protected A431 cells from the conjugate cytotoxicity. This immunoconjugate might be useful for targeted treatment of squamous cell carcinomas hyperexpressing EGFR.
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PMID:Epidermal growth factor receptor-dependent cytotoxic effect of anti-EGFR antibody-ribonuclease conjugate on human cancer cells. 1062 69

To investigate the role of the multidrug resistance-associated protein (MRP1) homologue MRP5 in relation to platinum drug resistance, we examined the steady-state levels of the mRNAs for MRP5 in both lung cancer cell lines and peripheral mononuclear cells (PMN) after exposure to platinum drug and in normal lung and lung cancer tissue specimens. Firstly, we examined MRP5 gene expression levels in 80 autopsy samples (40 primary tumors and 40 corresponding normal lung tissues) from 40 patients who had died from lung cancer. Next, we monitored MRP5 gene expression levels within 24 hr in both lung cancer cell lines incubated with cisplatin and in PMN from 10 previously untreated lung cancer patients after carboplatin administration alone. The MRP5 gene expression levels were assessed by quantitative reverse transcription polymerase chain reaction or RNase protection assay. The MRP5 expression levels in normal lung tissues and in tumors from patients exposed to platinum drugs during their lifetime were significantly higher than those in tissues from non-exposed patients. On the other hand, the MRP5 expression levels were not rapidly induced by platinum drugs either in lung cancer cell lines or in PMN within 24 hr. Our results suggest that increased expression levels of the MRP5 gene are associated with exposure to platinum drugs in lung cancer in vivo and/or the chronic stress response to xenobiotics.
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PMID:Increased expression of the MRP5 gene is associated with exposure to platinum drugs in lung cancer. 1072 1

A hallmark of small cell lung carcinoma (SCLC) is the expression of autocrine growth factors such as neurotensin and gastrin-releasing peptide, which bind to cellular receptors and stimulate cell division. The biological activity of autocrine growth factors requires the concurrent expression of prohormone convertases that cleave the growth factors to their active form, suggesting the expression of these genes is linked in SCLCs. RNase protection assays were used to detect the expression of autocrine growth factor and prohormone convertase mRNAs in a panel of lung cancer cell lines. These mRNAs are coexpressed in SCLC and lung carcinoid cell lines, but not in normal lung epithelium or in non-small cell lung cancers. These findings, together with earlier results from our laboratory, suggest the expression of prohormone convertases has an important role in the development and maintenance of the SCLC phenotype and that autocrine growth factor and prohormone convertase genes respond to a common transcriptional activator in SCLC.
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PMID:Prohormone convertase and autocrine growth factor mRNAs are coexpressed in small cell lung carcinoma. 1091 24

This report describes the validation of a polymerase chain reaction aided transcript titration assay (PATTY) for tumor samples. The results obtained with the PATTY were compared to those of RNase protection in a set of 7 human lung cancer cell lines and in 23 non-small cell lung cancer samples derived from resected patients. Whereas between PATTY and RNase protection assay a good correlation was observed in the cell lines (r = 0.74, p = 0.057), no correlation was observed within the tumor samples (r = 0.06, p = 0.78). This was also the case when only tumors with a high percentage of tumor cells (> 90%) were selected. Although PATTY is a valuable tool to measure mRNA expression in cell lines, our results caution the use of PATTY in human tumor samples without proper validation. The possible causes of these results are discussed.
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PMID:Validation of a polymerase chain reaction aided transcript titration assay (PATTY) for topoisomerase II in lung cancer samples. 1113 61

Acquired anticancer drug resistance in cancer cells is often a result of an increase in levels of the ATP binding cassette (ABC) transporters that export anticancer drugs from cancer cells, suggesting that anticancer drugs may induce genes that mediate drug resistance in cancer cells. In this study, the induction of anticancer drug transporter gene expression by Adriamycin was examined in human lung cancer cell lines. Increased expression of MDR1, MRP5 and SMRP mRNA was observed 48 hr after the initiation of Adriamycin exposure in human lung cancer PC-14 cells and cisplatin-resistant PC-14/CDDP cells, in a dose-dependent manner as measured by TaqMan real-time RT-PCR. The levels of MRP-1, MRP2 and LRP mRNA were not altered by Adriamycin exposure. The biologic functions of the MRP5 and SMRP genes have not been fully clarified. To elucidate the relationship between Adriamycin resistance and MRP5 and SMRP, mRNA levels of MRP5 and SMRP in Adriamycin-resistant cell lines were compared with the parental cells. Increased expression of MRP5 and SMRP mRNA was observed in all 3 cell lines (SBC-3/ADM, AdR MCF7 and K562/ADM) by Northern blot analysis and RNase protection assay. These results suggest that subacute exposure of lung cancer cells to Adriamycin induced MRP5 and SMRP and that long-term exposure with Adriamycin selected the MRP5- and SMRP-overexpressing lung cancer cells. MRP5 and SMRP is a candidate molecule for acquired Adriamycin resistance in addition to MDR1.
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PMID:Induction of MRP5 and SMRP mRNA by adriamycin exposure and its overexpression in human lung cancer cells resistant to adriamycin. 1174 26


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