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)

Recombinant methioninase (rMETase) is a homotetrameric pyridoxal 5'-phosphate enzyme of 172-kda molecular mass derived from Pseudomonas putida and cloned in Escherichia coli. rMETase has been found previously to be an effective, anti-tumor agent in vitro and in vivo. The enzyme targets the elevated minimal methionine requirement seen in all tumor types. In order to prevent immunological reactions which might be produced by multiple dosing of rMETase and to prolong the serum half-life of rMETase, the N-hydroxysuccinimidyl ester of methoxypolyethylene glycol propionic acid (M-SPA-PEG 5000) has been coupled to rMETase. Molar ratios of M-SPA-PEG-5000 (PEG) to rMETase from 10 to 40 were used for PEGylation of rMETase. PEGylation reactions were run at 20 degrees C for 30 to 60 min in reaction buffer (20 mM sodium phosphate buffer, pH 8.3). The PEGylated molecules (PEG-rMETase) were purified from unreacted PEG with Amicon 30 K centriprep concentrators or by Sephacryl S-300 HR gel-filtration chromatography. Unreacted rMETase was removed by DEAE Sepharose FF anion-exchange chromatography. The resulting PEG-rMETase subunit, from a PEG/rMETase ratio of 30/1 in the synthetic reaction, had a molecular mass of approximately 53 kda determined by matrix-assisted laser desorption/ionization mass spectrometry, indicating the conjugation of two PEG molecules per subunit of rMETase and eight per tetramer. PEG-rMETase molecules obtained from reacting ratios of PEG /rMETase of 30/1 had enzyme activities of 70% of unmodified rMETase. PEGylation of rMETase increased the serum half-life of the enzyme in rats to approximately 160 min compared to 80 min for unmodified rMETase. PEG-rMETase could deplete serum methionine levels to less than 0.1 microM for approximately 8 h compared to 2 h for rMETase in rats. Efficacy studies of PEG-rMETase on human lung cancer and kidney cancer cells in vitro demonstrated a 50% inhibitory concentration (IC50) of 0.04 and 0.06 units/ml, respectively. These IC50 values were almost identical to unmodified rMETase, thus indicating maintenance of antitumor efficacy in the PEGylated enzyme. PEG-rMETase had an IC50 for normal lung and kidney cells of 0.8 and 1.5 units/ml, respectively, similar to rMETase. The efficacy data indicated that PEG-rMETase maintained the high level tumor selectivity of rMETase. PEG-rMETase injected intravenously in mice demonstrated a tumor/blood retention ratio of approximately 1/6 compared to 1/10 of unmodified enzyme, indicating that PEG-rMETase distributes to the tumor at least as effectively as rMETase.
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PMID:Polyethylene glycol conjugation of recombinant methioninase for cancer therapy. 947 56

Hepatocyte growth factor (HGF)/scatter factor (SF) is a multifunctional factor that stimulates epithelial cell motility, invasion and morphogenesis. Its receptor is a transmembrane tyrosine kinase encoded by the Met proto-oncogene. Several studies have suggested a possible role for HGF/Met in tumor development and progression. To investigate the potential roles of Met in human lung cancer biology, we have studied the mRNA and protein expression of Met in normal lung tissue, primary non-small cell lung carcinoma (NSCLC), and NSCLC cell lines. The results indicated a differential pattern of Met expression among various subtypes of NSCLC. The majority of squamous cell carcinoma (SQCC), either in vivo or in vitro, expressed Met mRNA and its protein product at levels much lower than or similar to normal lung tissue or bronchial epithelium. Moreover, SQCC characteristically over-expressed a variant Met mRNA which corresponds to a 5' partially deleted transcript produced by alternative splicing. In contrast, the expression of Met mRNA and its protein product in adenocarcinoma (ADC) and large cell undifferentiated carcinoma were more heterogeneous. Overexpression was demonstrated in approximately 35% and 20% of these subtypes of NSCLC, respectively. Among ADC, intermediate to high levels of Met immunoreactivity correlated with greater degree of tumor differentiation. Furthermore, an accentuation of Met immunoreactivity was often noted in cancer cells at the advancing edge of tumors. These findings support a role for Met in lung cancer cell invasion and differentiation in vivo, but its expression and functions may be modified by the differentiation phenotype of the tumor cells.
Lung Cancer 1998 Apr
PMID:Differential expression of Met/hepatocyte growth factor receptor in subtypes of non-small cell lung cancers. 969 82

Recombinant lambda light chain of lung cancer-reacting human monoclonal antibody HB4C5 was expressed in Escherichia coli. Expression in bacteria ensured the generation of homogeneous light chain species devoid of activity-hampering N-linked glycosylation usually found in the light chain CDR-1 of HB4C5. Molecular engineering was also employed to eliminate the C-terminal two amino acid residues, i.e., Cys and Ser, to prevent the formation of lambda light chain dimers which are less reactive than the monomeric form. The lambda light chain was overexpressed in E. coli as inclusion bodies, which were solubilized, refolded, and treated with Aeromonas proteolytica aminopeptidase to remove the N-terminal Met with subsequent natural cyclization of the penultimate Gln residue to pyroglutamate, the same N-terminal end as that of naturally occurring lambda light chain in HB4C5. Monomeric recombinant lambda light chains, both before and after removal of the N-terminal Met residue, were 40 times more immunoreactive than the parent HB4C5. The immunostaining of lung cancer tissue sections with the recombinant lambda light chain indicated cancer-specific reactions to all specimens of adenocarcinoma, squamous cell carcinoma and large cell carcinoma histologies, but did not react with small cell carcinoma. Tumor radioimmunoimaging experiments in LC6 (lung squamous cell carcinoma line)--xenografted nude mice by the i.p. injection of 125I-labeled recombinant lambda light chain and 125I-labeled human lambda light chain control gave tumor-specific and recombinant lambda light chain-dependent images on day 5 postinjection, and images were also detectable on day 3. Biodistribution studies with 125I-labeled recombinant lambda light chain demonstrated that the lambda light chain could penetrate better into the tumor sites, both at the necrotic and solid parts of the xenograft, as compared to our previous results with 125I-labeled HB4C5 which could localize to the necrotic part only. These results suggest that the recombinant lambda light chain is potentially useful as a lung cancer-targeting vehicle, for such as radioimmunoimaging and radioimmunotherapy, with least possible adverse immunogenic effects.
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PMID:Recombinant light chain of human monoclonal antibody HB4C5 as a potentially useful lung cancer-targeting vehicle. 1040 32

The present study was undertaken to examine the mechanistic basis for the recent observation that the pyridine nucleotide derivative 6-aminonicotinamide (6AN, NSC 21206) enhances the accumulation and resulting cytotoxicity of cisplatin in a variety of tumor cell lines. When A549 lung cancer cells or K562 leukemia cells were treated with 62.5 microM 6AN for 21 h and then pulse-labeled with [(35)S]methionine for 1 h, increased labeling of five polypeptides, one of which corresponded to a M(r) approximately 78,000 glucose-regulated protein (GRP78), was observed. Two subsequent observations, however, suggested that up-regulation of these polypeptides was unlikely to explain the interaction between 6AN and cisplatin: 1) the concentration of 6AN required to induce GRP78 was 4-fold higher than the dose required to sensitize cells to cisplatin; and 2) simultaneous treatment of cells with 6AN and cycloheximide prevented the increase in GRP78 but not the sensitizing effect of 6AN. On the contrary, treatment with the protein synthesis inhibitors cycloheximide, anisomycin, or puromycin as well as prolonged exposure to the RNA synthesis inhibitor actinomycin D mimicked the biochemical modulating effects of 6AN on cisplatin action. Conversely, 6AN inhibited protein synthesis, whereas 18 6AN analogs that failed to enhance Pt-DNA adducts and cisplatin cytotoxicity failed to inhibit protein synthesis. These observations are consistent with a model in which 6AN and other inhibitors of protein synthesis act as modulating agents by increasing cisplatin accumulation, thereby enhancing the formation of Pt-DNA adducts and subsequent cisplatin-induced cell death.
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PMID:Effect of 6-aminonicotinamide and other protein synthesis inhibitors on formation of platinum-DNA adducts and cisplatin sensitivity. 1069 93

Squamous cell lung carcinomas (SCC) from former employees of the Wismut uranium mining company (Saxony, Germany) were obtained from the Stollberg Archive in order to screen for p53 tumour suppressor gene codon 249 arg-->met hotspot mutations, a putative molecular bio-dosimeter of alpha-particle (radon) exposure (Taylor et al (1994) Lancet 343: 86-87; McDonald et al (1995) Cancer Epidemiol Biomarkers Prevent 4: 791-793). Of the 29 archived samples of SCC meeting quality criteria for DNA analysis by polymerase chain reaction (PCR) and Haelll restriction enzyme digestion, two tumours were found that harboured this mutation. DNA sequencing confirmed the presence of a G to T base substitution within the Haelll site spanning codons 249 and 250 of the p53 gene that results in replacement of arginine (wild-type) by methionine at residue 249. When these data are combined with those from our previous study of tumours from the Stollberg Archive in which 50 lung tumours were examined, (including nine SCCs), we conclude that the G-->T (arg-->met) codon 249 mutation prevalence in the Wismut miner cohort is not sharply elevated in lung cancers in general (two mutations/79 tumours), or specifically in SCCs of the lung (two mutations/38 SCC) when compared to data from lung cancer patients with no reported occupational exposure to radon gas.
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PMID:Analysis of radon-associated squamous cell carcinomas of the lung for a p53 gene hotspot mutation. 1073 42

We have previously demonstrated the antitumor efficacy of recombinant methioninase (rMETase) derived from Pseudomonas putida. To enhance the efficacy of rMETase, we have constructed the pLGFP-METSN retrovirus encoding the P. putida methioninase (MET) gene fused with the green fluorescent protein (GFP) gene. pLGFP-METSN or control vector pLGFPSN was introduced into the human lung cancer cell line H460. The methionine level of H460-GFP-MET cells was reduced to 33% of that of H460-GFP cells. rMETase (0.08 U/mL) in the medium resulted in 10% survival of H460-GFP-MET cells compared with untreated cells in vitro. In contrast, rMETase-treated H460-GFP cells survived at 90% of control. Tissue fragments harvested from subcutaneous tumors of H460-GFP-MET or H460-MET were implanted by surgical orthotopic implantation into the lungs of nude mice. A suboptimal dose of rMETase was administered intraperitoneally daily to mice in each group. Overall survival of rMETase-treated animals with H460-GFP-MET tumors was significantly longer than either rMETase-treated or -untreated animals with H460-GFP tumors (P < .05 in log-rank test). In two repeat experiments, rMETase-treated animals with H460-GFP-MET tumors had a 30-day survival of 80% and 83%, respectively. Untreated animals with H460-GFP-MET tumors had a 30-day survival of 40% and 58%, respectively. rMETase-treated animals with H460-GFP tumors had a 30-day survival of 0% and 33%, respectively. Untreated animals with H460-GFP tumors had a 30-day survival of 0% and 33%, respectively. The retrovirus-mediated gene transfer of METase decreased the intracellular methionine level of tumor cells and consequently enhanced the efficacy of treatment with the rMETase protein. We have thus demonstrated a new strategy of combination tumor therapy with the gene and gene product of MET.
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PMID:Survival efficacy of the combination of the methioninase gene and methioninase in a lung cancer orthotopic model. 1077 Jun 44

Epidemiological studies have shown that inhalation of radon, a radioactive gas, is associated with an increased risk for lung cancer. We have developed a model of radon-induced rat lung tumors to characterize cytogenetic and molecular events involved in radon-induced lung tumorigenesis. Using comparative genomic hybridization (CGH), gains and losses of genetic material were investigated in a series of 13 carcinomas and four adenomas of the lung. Frequent losses occurred at 4q12-21, 5q11-33, and 15q, which are homologous to human chromosome (HSA) bands 7q21-36, 1p31-36/9p21-31, and 13q14.1-14.3/3p14.2, respectively. These regions are frequently (30-80%) deleted in human lung cancer and contain tumor suppressor genes or proto-oncogenes such as MET, CDKN2A/p16/MTS1, CDKN2B/p15/MTS2, FHIT, and RB1 or yet to be identified genes. Frequent gains involved 6, 7q34-qter, and 19q; chromosomes 6 and 7 being homologous to human 2p21-25 and 8q21-24 where the MYCN and MYC oncogenes are located. The genetic similarities between rat and human lung cancer suggest common underlying mechanisms for tumor evolution in both species. Moreover, cytogenetic and molecular genetic analyses of radon-induced rat lung tumors could help to better understand the development and progression of radon-induced lung cancer in man.
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PMID:CGH analysis of radon-induced rat lung tumors indicates similarities with human lung cancers. 1091 87

The human RON gene (MST1R) maps to 3p21.3, a region frequently altered in lung cancer and other malignancies. It encodes a receptor tyrosine kinase (RTK) closely related to MET, whose mutations are associated with neoplasia. We investigated whether RON might be involved in the development or progression of lung cancer. We first determined the exon-intron structure of the gene by direct sequencing of RON cosmid DNA and PCR products containing intronic sequences, and then developed primers suitable for mutation analysis by the single-strand conformation polymorphism (SSCP) method. Twenty coding exons were characterized, all but the first one small (average size: 170 bp), a feature shared with other RTK genes. We performed SSCP analysis of RON in small and non-small cell lung cancer samples, upon detection of its expression in a sample of lung cancer cell lines. A mutation (T915C: L296P) was found in an adenocarcinoma specimen. Several single nucleotide polymorphisms were also found. The panel of intron-anchored primers developed in this work will be useful for mutation analysis of the RON gene in different types of human tumors.
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PMID:Gene structure of the human receptor tyrosine kinase RON and mutation analysis in lung cancer samples. 1095 94

We examined the tumorigenic and metastatic potentials of three human non-small cell lung cancer (NSCLC) cell lines, PC-14, A549 or Lu-99 cell lines suspended in Matrigel-containing phosphate-buffered saline were orthotopically implanted into the lungs of nude mice. The formation of a solitary tumor nodule in the lung was observed after the implantation of all cell lines. Intrapulmonary implantation of PC-14 or Lu-99 cells resulted in spontaneous distant metastases. In contrast, A549 cells caused multiple intrapulmonary metastases to the right and left lobes of the lung without producing visible lymphatic metastasis. We also investigated the expression of matrix metalloproteinases (MMPs), urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and c-MET in these cell lines in vitro and in vivo. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed that the expression of MMP-2 and membrane-type 1 MMP (MT1-MMP) was elevated in PC-14 as compared with the other two cell lines. In contrast, stronger expression of c-MET was observed in A549 than in PC-14 or Lu-99. These results indicate that differential patterns of metastasis of lung cancer might be associated with differential expression of metastasis-associated molecules. Our orthotopic implantation models display clinical features resembling those of NSCLC, and may provide a useful basis for lung cancer research.
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PMID:Solitary lung tumors and their spontaneous metastasis in athymic nude mice orthotopically implanted with human non-small cell lung cancer. 1100 66

[(18)F]-fluorodeoxyglucose and [(11)C]-methionine are tracers which are widely used in oncological positron emission tomography. This study has been designed to assess the deoxyglucose and methionine uptake behaviour in three cell lines from different lung cancer histotypes. Tracer uptake was compared with proliferative activity as determined by growth curves and tritiated thymidine uptake. Deoxyglucose paralleled thymidine in all cell lines, peaking in the lag phase, decreasing throughout the exponential phase, and reaching its minimum in the plateau phase. The correlation was statistically verified and Spearman's rho ranged from 0.79 to 0.99. The absolute methionine uptake was always highest and always peaked on day 2, followed by a quite rapid decrease. However, besides the delay in maximum uptake, methionine incorporation was also related to proliferation, although the statistical correlations were weaker. These results show for the first time a clear correlation between deoxyglucose uptake and cell proliferation in a model comparing tracer uptake in different growth phases. Although delayed, methionine uptake was also related to cell growth and its greater intensity could be of interest for clinical use.
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PMID:Uptake of tritiated thymidine, deoxyglucose and methionine in three lung cancer cell lines: deoxyglucose uptake mirrors tritiated thymidine uptake. 1112 81


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