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)

DAP kinase is a new type of calcium/calmodulin-dependent enzyme that phosphorylates serine/threonine residues on proteins. Its structure contains ankyrin repeats and the 'death' domain, and it is associated with the cell cytoskeleton. The gene encoding DAP kinase was initially isolated as a positive mediator of apoptosis induced by interferon-gamma, by using a strategy of functional cloning. We have now tested whether this gene has tumour-suppressive activity. We found that lung carcinoma clones, characterized by their highly aggressive metastatic behaviour and originating from two independent murine lung tumours, did not express DAP kinase, in contrast to their low-metastatic counterparts. Restoration of DAP kinase to physiological levels in high-metastatic Lewis carcinoma cells suppressed their ability to form lung metastases after intravenous injection into syngeneic mice, and delayed local tumour growth in a foreign 'microenvironment' Conversely, in vivo selection of rare lung lesions following injection into syngeneic mice of low-metastatic Lewis carcinoma cells or of DAP kinase transfectants, was associated with loss of DAP kinase expression. In situ TUNEL staining of tumour sections revealed that DAP kinase expression from the transgene raised the incidence of apoptosis in vivo. DAP-kinase transfectants also showed increased sensitivity in vitro to apoptotic stimuli, of the sort encountered by metastasizing cells at different stages of malignancy. We propose that loss of DAP kinase expression provides a unique mechanism that links suppression of apoptosis to metastasis.
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PMID:DAP kinase links the control of apoptosis to metastasis. 936 56

To create cytotoxic hybrid analogs of somatostatin (SST), octapeptides RC-160 (D-Phe-Cys-Tyr-D-Trp- Lys-Val-Cys-Trp-NH2) and RC-121 (D-Phe-Cys-Tyr-D-Trp- Lys-Val-Cys-Thr-NH2) were linked to doxorubicin (DOX) or its superactive derivative, 2-pyrrolino-DOX (AN-201). The conjugation was performed by coupling N-9-fluorenylmethoxycarbonyl (N-Fmoc)-DOX-14-O-hemiglutarate or 2-pyrrolino-DOX-14-O-hemiglutarate to the amino terminus of [Lys(Fmoc)5]RC-160 yielding AN-163 and AN-258, respectively, after deprotection. The respective cytotoxic conjugates of RC-121 (AN-162 and AN-238) were prepared similarly. In vitro tests on human cancer cell lines-MKN-45 gastric cancer, MDA-MB-231 breast cancer, PC-3 prostate cancer, and MIA PaCa-2 pancreatic cancer-demonstrated that the antiproliferative activity of the cytotoxic radicals in these conjugates was virtually retained. In H-345 human small cell lung carcinoma cell line, conjugates of RC-121 preserved the cytotoxic activity of their radicals, but the hybrids with RC-160 showed approximately 10 times lower activity. The ability of the carriers and the hybrids to inhibit the binding of 125I-labeled RC-160 to receptors for SST on rat pituitary membrane preparation was also determined. The cytotoxic conjugates inhibited 50% of the specific binding of the radioligand in the nanomolar concentration range (IC50 < 80 nM). When SST-like activities of AN-238 and its carrier, RC-121, were compared in the rat pituitary superfusion system, both compounds were found to suppress a stimulated growth hormone release at nanomolar concentrations. Preliminary studies in animal models of breast and prostate cancers showed that AN-238 is less toxic than AN-201 and more potent in inhibiting tumor growth. These highly active cytotoxic analogs of SST have been designed as targeted antitumor agents for the treatment of various cancers expressing receptors for SST octapeptides.
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PMID:Synthesis and biological evaluation of cytotoxic analogs of somatostatin containing doxorubicin or its intensely potent derivative, 2-pyrrolinodoxorubicin. 946 96

p21waf1/cip1 mRNA and protein accumulate in intact cells exposed to oxidizing agents through a p53-independent, MAPK-dependent mechanism. Treatment with oxidizing agents also yields a second form of this protein (FM p21), characterized by a faster migration on SDS-PAGE. This phenomenon depends on the modification of intracellular redox conditions induced by diethylmaleate, a glutathione-depleting agent, being prevented by the pretreatment with the glutathione precursor N-acetylcysteine. The appearance of this FM p21 form is very early, being observed 5 min after exposure to diethylmaleate, long before the already observed accumulation of p21 induced by oxidative stress. Furthermore, experiments with dominant negative mutants of MEK demonstrate that, in contrast with that observed for the oxidative stress-induced accumulation of p21 mRNA and protein, the appearance of FM p21 form is not dependent from the activation of the MAPK pathway. It was previously observed (Tchou et al, 1996) that in some lung carcinoma cells long exposure to high doses of phorbol esters also induces the appearance of a faster-migrating p21 electrophoretic band and it was suggested that this could result from a different phosphorylation or from a proteolytic processing at the C-terminus of the protein. The latter is not the case for the diethylmaleate-induced FM p21 whose C-terminus is intact, as demonstrated by the expression of a C-terminus tagged p21 cDNA. On the contrary, the observed migration shift seems to be dependent on the hypophosphorylation of the protein; in fact, a pretreatment of cells with okadaic acid, an inhibitor of (serine/threonine) phosphatases, inhibits the oxidation-dependent appearance of the FM p21 and the block of protein synthesis, caused by cycloeximide, does not affect the appearance of FM p21, that thus could derive from the dephosphorylation of preexisting protein.
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PMID:A new p21waf1/cip1 isoform is an early event of cell response to oxidative stress. 984 80

Two new modified uracil nucleosides, 5-carbamoylmethyuridine (ncm5U, I) and 5-carbamoylmethyl-2-thiouridine (ncm5s2U, II) were isolated from a 24 hr collection of a normal human urine. The structures were assigned on the basis of UV, NMR and mass spectral data and confirmed by comparison of the spectral data and HPLC mobilities with those of authentic samples. On the basis of experimental data it appears possible that 5-carbamoylmethyl-2-thio-uridine (ncm5s2U, II) may be a degradation product produced from a labile precursor by the chemical treatments during the isolation procedure. However, the other nucleoside (ncm5U,I) certainly appears to be of metabolic origin and was also found in the urines of one chronic myelogenous leukemia and one lung carcinoma patient. Abbreviations used are: tRNA-transfer ribonucleic acid, TMS-trimethylsilyl, RP-HPLC--reverse phase high performance liquid chromatography, EI--electron impact, cm5U-5-carboxymethyluridine, mcm5U-5-methoxycarbonylmethyluridine, cm5s2U-5-carboxymethyl-2-thiouridine, mcm5s2U-5-methoxycarbonylmethyl-2-thiouridine, t6A-9-beta-D-ribofuranosyl-[N(purin-6-yl)carbamoyl]-1-threonine, C-cytidine, acp3u-3-(3-amino-3-carboxypropyl)uridine, AICR-aminoimidazole carboxamide riboside, alpha-4-PCNR & beta-4-PCNR-9-alpha-D-(or beta-D)-ribofuranosyl-pyridin-4-one-3-carboxamide, H x 7R-7-beta-D-ribofuranosyl hypoxanthine, m3U-3-methyluridine, m1I-1-methylinosine, m1G-1-methylguanosine, DI-5'-deoxyinosine, dms5OA-5'-deoxy-5'-methylthioadenosine sulfoxide, m2(2)G-N2-dimethylguanosine, psi-psi-uridine, A-adenosine, I-inosine, CML-chronic myelogenous leukemia mam5s2U-5-methylaminomethyl-2-thiouridine, ncm5U-5-carbamoylmethyluridine, ncm5s2U-5-carbamoylmethyl-2-thiouridine, UV-ultraviolet, NMR-nuclear magnetic resonance, HPLC-high performance liquid chromatography, GC-MS-gas chromatography-mass spectrometry.
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PMID:Isolation and characterization of 5-carbamoylmethyluridine and 5-carbamoylmethyl-2-thiouridine from human urine. 1061 23

In the human lung carcinoma cell line A549, Taxol (20 nM) causes a decreased electrophoretic mobility of the 66-kDa Shc isoform (p66shc), beginning 4 h after drug exposure, and reaching a maximum at 9-18 h. No shift was observed for the 52- and 46-kDa isoforms of Shc. The electrophoretic mobility shift of p66shc caused by Taxol is not the result of tyrosine phosphorylation, and there is no indication of a Shc/Grb2 complex in Taxol-treated A549 cells. This modification is blocked by the serine/threonine protein phosphatase 2A. In vivo 32P-labeling and subsequent phosphoamino acid analysis of p66shc indicated that both the original and the shifted p66shc were predominantly serine phosphorylated. Cyanogen bromide digestion of p66shc produced a phosphorylated fragment with an apparent molecular weight of approximately 7.9 kDa from the untreated cells and two phosphorylated fragments, of approximately 7.9 and approximately 9.6 kDa, from the Taxol-treated cells. The domain of Taxol-induced serine phosphorylation is thought to be in the cyanogen bromide fragment containing residues 2-65. The Taxol-induced electrophoretic mobility shift of p66shc was inhibited by the protein synthesis inhibitor, cycloheximide, but not by the mitogen-activated and extracellular signal-regulated protein kinase kinase (MEK) inhibitor, PD98059. This mobility shift did not occur in Taxol-resistant A549-T12 cells treated with 20 nM Taxol. In addition to Taxol, other microtubule-interacting drugs caused a decreased electrophoretic mobility of p66shc. This Taxol-mediated serine phosphorylation seen in p66shc may result from a MEK-independent signaling pathway that is activated in cells that have a prolonged or abnormal mitotic phase of the cell cycle and may play a role in signaling events that lead to cell death.
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PMID:Taxol mediates serine phosphorylation of the 66-kDa Shc isoform. 1101 45

Constitutive activation of the Wnt signaling pathway as a result of genetic alterations of APC, AXIN1, and CTNNB1 has been found in various human cancers, including those of the colon, liver, endometrium, ovary, prostate, and stomach. To investigate the pathogenetic significance of constitutive activation of the Wnt signaling pathway in human lung carcinogenesis, CTNNB1 alterations in exon 3, a region known to represent a mutation hot spot, were screened in 46 lung cancer cell lines and 47 primary lung cancers. Missense mutations causing substitutions of Ser/Thr residues critical for regulation by GSK-3beta were detected in one (2%) of the cell lines, A427, and two (4%) of the surgical specimens. The three lung cancers with CTNNB1 mutations were adenocarcinomas. To explore the prevalence of constitutive activation of the Wnt signaling pathway in human lung cancer, we assessed 15 lung cancer cell lines representing major histological subtypes of lung cancers for constitutive Tcf transcriptional activity (CTTA). CTTA was observed only in the A427 adenocarcinoma cell line, but not in the remaining 14 cell lines. The data indicate that constitutive activation of the Wnt signaling pathway caused by CTNNB1 mutation is involved in the development and/or progression of a subset of lung carcinoma, preferentially in adenocarcinoma.
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PMID:Constitutive activation of the Wnt signaling pathway by CTNNB1 (beta-catenin) mutations in a subset of human lung adenocarcinoma. 1117 Feb 92

DAP-kinase is a pro-apoptotic Ca(2+) calmodulin-regulated serine/threonine kinase that participates in a wide array of apoptotic systems initiated by interferon-gamma, TNF-alpha, activated Fas, and detachment from extracellular matrix. It was isolated by an unbiased functional approach to gene cloning aimed at hitting central mediators of the apoptotic process. This 160 Kd protein kinase is localized to actin microfilaments and carries interesting modules such as ankyrin repeats and the death domain. The death promoting effects of DAP-kinase depend on its intact catalytic activity, the correct intracellular localization, and on the presence of the death domain. A few mechanisms restrain the killing effects of the protein in healthy cells. The enzyme's active site is negatively controlled by an adjacent CaM regulatory domain whose effect is relieved by binding to Ca(2+)-activated calmodulin. A second mode of autoinhibition engages the serine-rich C-terminal tail, spanning the last 17 amino acids of the protein. A link between DAP-kinase and cancer has been established. It was found that the mRNA and protein expression is frequently lost in various human cancer cell lines. Analysis of the methylation status of DAP-kinase's 5' UTR in DNA extracted from fresh tumor samples, showed high incidence of hypermethylation in several human carcinomas and B cell malignancies. The anti-tumorigenic effect of DAP-kinase was also studied experimentally in mouse model systems where the re-introduction of DAP-kinase into highly metastatic mouse lung carcinoma cells who had lost the protein, strongly reduced their metastatic capacity. Thus, it appears that loss of DAP-kinase confers a selective advantage to cancer cells and may play a causative role in tumor progression. A few novel kinases sharing high homology in their catalytic domains with DAP-kinase have been recently identified constituting altogether a novel family of death promoting serine/threonine kinases.
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PMID:DAP-kinase: from functional gene cloning to establishment of its role in apoptosis and cancer. 1131 98

Motility and adhesiveness are regulated by a multitude of factors, including cytoskeletal polymerization and phosphorylation of cytoskeletal and associated proteins. The metastatic Lewis lung carcinoma variant, LLC-LN7, was highly motile in vitro and had lower levels of the serine/threonine protein phosphatase PP-2A than did the nonmetastatic variant, LLC-C8. Reducing PP-2A activity of the nonmetastatic cells pharmacologically or with catalytic (Calpha) subunit antisense increased their in vitro motility. Nonmetastatic LLC-C8 cells had a greater proportion of polymerized tubulin which co-purified with PP-2A as compared to the metastatic LLC-LN7 cells. The PP-2A that was associated with the microtubules of these cells showed similar ratios of the Aalpha structural subunit to the Calpha/beta catalytic subunits. In contrast, the proportion of the regulatory subunit B56alpha was lower in the nonmetastatic LLC-C8 cells as compared to the metastatic LLC-LN7 cells. These studies show the role of PP-2A in restricting the motility of nonmetastatic tumor cells and suggest that the loss of this regulatory control in metastatic LLC-LN7 cells may be due to both a reduction in microtubule-associated PP-2A and a difference in the composition of the subunits of PP-2A that is associated with the microtubules.
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PMID:Differences in association of the serine/threonine protein phosphatase PP-2A with microtubules of metastatic and nonmetastatic tumor cells. 1146 73

Protein kinase C, a family of serine-threonine protein kinases, mediates a variety of intracellular signaling events. Here, the regulatory effect of phorbol 12-myristate 13-acetate(PMA)on the several PKC isozymes in the human lung carcinoma cells A-549 was studied. The expression of PKC-alpha PKC-betaII PKC-gamma PKC-delta and PKC-epsilon in A-549 cells was examined. No detectable PKC-zeta was observed. Short-term treatment of cells with PMA led to the translocation of these PKC isozymes, to different extent, from cytosol to cell membrane. Whereas, prolonged treatment of cells with PMA pronouncedly reduced the levels of PKC-alpha PKC-gamma PKC-delta and PKC-epsilon, but the intracellular level of PKC-betaII was not affected. Furthermore, PMA was observed to have differential effects on the down-regulation of PKC isozymes located in the cytosol and of those located in the membrane. Prolonged PMA treatment caused extensive decrease in the levels of cytosolic PKC-delta and PKC-gamma, and depleted cytosolic PKC-alpha and PKC-betaII. However, the amount levels of membrane PKC-alpha PKC-betaII PKC-gamma PKC-delta isozymes were not decreased. In contrast, PKC-epsilon in both cytosol and membrane fraction was obviously down-regulated by prolonged PMA treatment. This study provided novel evidence on the PMA-mediated activation and down-regulation of different PKC isozymes, which might be helpful in deepening our understanding on the roles of PKC activation and the alterations of their intracellular levels in processes of chemical carcinogenesis.
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PMID:Regulation of Protein Kinase C in A-549 Cells by Phorbol Ester. 1205 80

The objective of the present work was to investigate the existence of an oxytocin (OT)-mediated autocrine/paracrine signaling upon small cell carcinoma of the lung (SCCL) cell growth. In that view, OT receptor (OTR) expression, concomitant with OT synthesis and secretion, was evidenced on three different SCCL cell lines (DMS79, H146, and H345) and related to the vasopressin (VP) system. Specific OT, VP, OTR, V1a VP receptor (V1aR), and V1b/V3 VP receptor (V1bR/V3R) transcripts were identified by reverse transcription-PCR in all cell lines studied. Binding of 125I-(d(CH2)(5)(1), Tyr(Me)(2),Thr(4),Orn(8),Tyr(9)-NH2)-vasotocin (OVTA) was observed on all SCCL cell lines, with a K(d) (dissociation constant) ranging from 0.025-0.089 nM, depending on the cell line and the analytical method. Selectivity of 125I-OVTA binding was confirmed by displacement curves obtained with various OTR and VP receptor agonists and antagonists (OT, OVTA, L-371,257, VP, F180). Immunocytochemistry identified cellular OT and VP, and peptide secretion was measured in supernatants of SCCL cultures. [3H]Thymidine incorporations, applied on H345 cells, demonstrated a dose-dependent mitogenic effect of exogenous OT (1 and 100 nM) that was abolished by the OTR antagonist OVTA. A decrease of proliferation was also observed with OVTA alone, showing a functional mitogenic effect of tumor-derived OT. Taken together, these observations demonstrate the existence of a functional OT-mediated autocrine/paracrine signaling actively implicated in growth and development of SCCL tumors. Furthermore, these findings point to the potential of OT antagonists for development as therapeutic agents for the treatment of SCCL.
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PMID:Oxytocin synthesis and oxytocin receptor expression by cell lines of human small cell carcinoma of the lung stimulate tumor growth through autocrine/paracrine signaling. 1218 18


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