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

---

Query: EC:3.1.30.2 (endonuclease)
18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Most humans in the United States have been infected with BK virus (BKV), a human papovavirus. Because BKV has oncogenic properties, we have investigated whether it may be a cause of human cancer. Basic principles of tumor virology imply that BKV-induced tumors should contain BKV DNA sequences. Therefore, we assayed (by molecular hybridization) DNA from human tumors and malignant cell lines for BKV DNA, using BKV [(32)P]DNA as probe. The BKV [(32)P]DNA was labeled in vitro (nick translation) to specific activities of 1 to 2 x 10(8) cpm/mug. The BKV DNA used to prepare our probes had the properties expected of authentic BKV genomes, including density of superhelical DNA, sedimentation velocity in alkaline and neutral sucrose gradients, production of one fragment by endonuclease EcoRI cleavage and four fragments by endonuclease Hin II + III cleavage and reassociation properties. From these studies we conclude that our BKV probes hybridized well, and represented bona fide BKV DNA. Using three different BKV [(32)P]DNA probes, i.e., from three distinct plaque isolates, we have analyzed DNA from BKV-transformed cells, normal human tissues, and a large number of human tumors. All human DNAs (cell lines, normal tissues, tumors) hybridized 5% with BKV DNA. Hybridization analysis of BKV-transformed hamster cell DNA indicated 5-6 copies of at least 88% of the BKV genome per cell. No BKV DNA sequences were detected (above the normal 5% hybridization to all human DNAs) in the following normal human tissues: 10 kidney (BKV is usually isolated from urine), 3 spleen, 13 lung, 23 colon, 2 rectum, 1 ileum, and 1 skin. No BKV-specific DNA was found in 166 tumors, including 5 carcinomas (Ca) of stomach, 3 Ca small intestine, 26 Ca colon, 9 Ca rectum, 31 Ca lung, 9 adenocarcinomas and 5 oat cell carcinomas of lung, 17 melanomas, 5 Ca prostate, 4 Ca bladder, 6 Wilms tumors, 4 hypernephromas, 15 Ca kidney, 7 brain tumors, 5 Hodgkin lymphomas, 10 lymphomas (immunosuppressed patients have a high incidence of lymphomas), 2 reticulum cell sarcomas (spleen), and 3 skin tumors. We have also analyzed 7 human malignant cell lines (melanoma, lung, rhabdomyosarcoma, and glioblastomas), including several clones of a lung melanoma line; no BKV DNA sequences were detected. Because our probes could detect one copy of BKV DNA if only 10% of the cells were tumor cells, our results are very strong evidence that the tumors we analyzed did not have a BKV etiology. The tumors we tested represent about 50% of all cancers in the United States; there is no evidence that BKV is involved in the etiology of these types of tumors.
...
PMID:Analysis of human tumors and human malignant cell lines for BK virus-specific DNA sequences. 20 40

Human cytochrome P450IIE1 (CYP2E) is involved in the metabolic activation of procarcinogens such as N-nitrosodimethylamine, benzene and ethyl carbamate. We screened DNA from 28 individuals for restriction fragment length polymorphisms (RFLPs) is the human P450IIE1 gene and detected an RFLP for the restriction endonuclease DraI. The distribution of the genotypes of this polymorphisms among lung cancer patients (n = 74) differed from that among controls (n = 73) with statistical significance of p < 0.05. In addition, the distribution among patients with cancers of the digestive system (n = 38) was also different from that among controls. Our findings indicate an association between the DraI polymorphism of the IIE1 gene and susceptibility to cancers of the lung and the digestive system.
...
PMID:Human cytochrome P450IIE1 gene: DraI polymorphism and susceptibility to cancer. 136 74

Cytochrome P450IIE1 (P450IIE1) is involved in metabolic activation of carcinogenic nitrosamines, aniline and benzene. We detected a restriction fragment length polymorphism of the human P450IIE1 gene with the restriction endonuclease DraI. The population was thus divided into three genotypes, namely, heterozygotes (CD) and two forms of homozygotes (CC and DD). The distribution of these genotypes among lung cancer patients differed from that among controls with statistical significance of P less than 0.05 (chi 2 = 7.01 with 2 degrees of freedom). This result strongly suggests that host susceptibility to lung cancer is associated with the DraI polymorphism of the P450IIE1 gene.
...
PMID:Association between restriction fragment length polymorphism of the human cytochrome P450IIE1 gene and susceptibility to lung cancer. 167 75

We have examined the epidermal growth factor (EGF) receptor gene for structural alterations in fresh human tumors. DNA samples from 92 patients with solid tumors (lung cancer, 37; breast cancer, 24; head and neck cancer, 17; other tumors, 14) were analyzed and compared with those from 22 leukemia patients and 14 individuals without malignant neoplasms. When DNA samples were digested with HindIII restriction endonuclease, Southern blot analysis demonstrated 3 distinct polymorphic bands (9.8, 11, and 12 kilobases) after hybridization to the HER-A64-1 probe and another 2 distinct polymorphic bands (4.9 and 5.2 kilobases) after hybridization to the HER-A64-3 probe. Pedigree analysis of 43 members of a single family and comparative analysis of tumor and normal DNA samples from the same patients demonstrated that the variations in fragment size observed were due to 2 independent restriction fragment length polymorphisms in the region of the EGF receptor gene. Amplification of the EGF receptor gene was detected in 3 cases of breast cancer, but not in other tumors studied. We conclude that the human EGF receptor gene has multiple restriction fragment length polymorphisms and that in fresh human tumor samples rearrangement and amplification of the gene occur infrequently, if ever, within the region encompassed by the 2 complementary DNA probes used.
...
PMID:Multiple restriction fragment length polymorphisms of the human epidermal growth factor receptor gene. 289 88

In ongoing studies, we have tested resected lung cancers from 41 men and 49 women; of those with primary lung cancer, 46 patients are free of disease and 35 have died of cancer or have persistent disease. Measurements and studies were as follows: total cellular deoxyribonucleic acid content by image analysis (n = 77); total genomic deoxyribonucleic acid methylation state and banding patterns from probed Southern blots (n = 36); radioimmunoassay for motilin, bombesin, gastrin, vasoactive intestinal peptide, and cholecystokinin (n = 18); and cytogenetic analysis (n = 39). All lung cancers were hyperploid. Adenocarcinomas and epidermoid carcinomas were generally hexaploid to nearly septaploid; comparisons by stage and histologic features suggested potential prognostic correlations. There was general hypomethylation of deoxyribonucleic acid (p less than 0.001). Deoxyribonucleic acid digests from restriction endonuclease Hpa II, when probed with deoxyribonucleic acid homologous to KPN, showed banding patterns that separated histologically indistinguishable primary adenocarcinomas and metastatic adenocarcinomas from one another. Cancers studied with radioimmunoassay were all negative for polypeptide hormones. Five cancers grew adequately in vitro to permit study of 190 detailed karyotypes (20 to 50 per tumor). Chromosome modal numbers ranged from 49 to 109. There were from 4 to 20 clearly abnormal marker chromosomes per tumor; abnormality derived from chromosome 1 was prevalent. Ten of 19 tumors xenotransplanted to nude mice were carried through two to five transplant generations without a change in histologic patterns.
...
PMID:Biochemical and cytogenetic studies of human lung cancers. 319 97

Polymerase chain reaction amplification and BstNI endonuclease digestion were performed on DNA isolated from cell lines that were either homozygous (SW480, A549) or heterozygous (Calu 1, SK-LU-1, A427) for K-ras codon 12 mutations. Polyacrylamide gel electrophoresis showed that both mutant and wildtype (WT) bands were present in Calu-1, SK-LU-1, and A427 cell DNA; only the mutant bands were observed with SW480 and A549 DNA. The percentages of mutant and WT fragments were measured using capillary electrophoresis (CE). Integration of mutant and WT peaks showed that the percentages of mutant alleles in Calu-1, SK-LU-1, and A427 cell lines were 73, 84, and 72, respectively. The sensitivity of the original BstNI assay for K-ras codon 12 in conjunction with analysis by CE was also tested by a series of titration experiments using one- and two-stage amplification-BstNI digestion protocols. CE was used to generate a calibration curve. The mutant allele was detected and the quantity was measured in the 1:100 and 1:10,000 dilutions in the one- and two-stage analysis, respectively. Four human lung adenocarcinomas were also analyzed. Two of these were homozygous normal, whereas the other two contained 63 and 32% codon 12 mutant alleles. These results showed that CE can separate and quantitate BstNI fragments containing K-ras codon 12 mutations. The high sensitivity and quantitative features of CE should enable detection and quantitation of mutant K-ras alleles in premalignant lung lesions, as well as exfoliated cells collected by cytology from persons at risk for lung cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Detection and quantitation of mutant K-ras codon 12 restriction fragments by capillary electrophoresis. 771 62

Polymorphic metabolism of certain chemical carcinogens may result in differences in susceptibility to cancers. Human CYP2E1 (cytochrome P450IIE1) is an enzyme involved in the metabolic activation of precarcinogens such as nitrosamines. We detected a restriction fragment length polymorphism (RFLP) of the human CYP2E1 gene for the restriction endonuclease Dra I. The distribution of this polymorphism was examined among lung cancer patients (n = 91), patients with cancer of the digestive tract (n = 45) and controls (n = 76). A significant difference in the distribution was observed between lung cancer patients and controls (chi 2 = 11.4 with 2 df; p < 0.005). On the other hand, there was no significant difference between patients between cancer of the digestive tract and controls (chi 2 = 4.87 with 2 df; NS). This finding suggests that the Dra I polymorphism of the CYP2E1 gene is associated with susceptibility to lung cancer. In addition, an association was found between the amount of lifelong smoking exposure and the distribution of the genotypes of the RFLP among lung cancer patients. The distribution pattern seemed deviated from that of controls especially in the population of low smoking exposure. Our Northern blot analysis data using RNA from human liver autopsy samples suggest that the Dra I polymorphism might be associated with the gene expression of CYP2E1 at mRNA level.
...
PMID:Restriction fragment length polymorphism of the human CYP2E1 (cytochrome P450IIE1) gene and susceptibility to lung cancer: possible relevance to low smoking exposure. 791 35

Consistent loss of DNA sequences from several regions on the short arm of human chromosome 3 has suggested that multiple tumor suppressor genes reside on chromosome 3p in various types of cancer cells. We have focused our efforts on an analysis of chromosomal band 3p21.1 since aminoacylase-1 (ACY1), which is localized to this band, has been shown to have lower levels of expression in several small cell and non-small cell lung cancer cell lines. Starting with two cosmids within 3p21.1, D3S92 and D3S93, we have isolated two separate contigs of overlapping cosmids within 3p21.1, by screening a library of 5700 chromosome 3-specific cosmid clones. Detailed restriction maps for these two contigs show that they contain multiple clusters of rare cutting restriction endonuclease sites. One contig extends for 100 kb and encompassed both ACY1 and D3S92, and the other extends about 80 kb around the D3S93 locus. Many different restriction fragments derived from these two contigs were found to be evolutionarily conserved and hybridized to distinct message transcripts. These fragments were used to identify homologous cDNAs from an adenogastric cDNA library, and several of these cDNAs were partially sequenced. We have identified five new genes from these two contigs and there is evidence to suggest that several additional genes reside within these cosmid contigs. The genes identified from 3p21.1 were then hybridized to DNA, isolated from a series of lung cancer cell lines and matched normal and tumor DNA from lung cancer patients. No alterations were detected with any of these probes, both at the DNA or RNA levels. A similar analysis with DNA fragments derived from these two genomic regions also failed to detect any alterations.
...
PMID:Isolation of two contigs of overlapping cosmids derived from human chromosomal band 3p21.1 and identification of 5 new 3p21.1 genes. 797 2

In the Tsukamoto-French model, ethanol causes an important 10-20-fold induction of ethanol-inducible cytochrome P4502E1 (CYP2E1), mediated through enzyme stabilization and increased rate of gene transcription. The CYP2E1 induction results in a pronounced increase in the rate of NADPH-dependent microsomal lipid peroxidation, an elevation which is not seen after simultaneous administration of the CYP2E1 inhibitor diallylsulfide. Increased amounts of lipid peroxides are seen in plasma and red blood cells of both rats and humans during high ethanol intake. A mechanism for ethanol-dependent liver damage is proposed which involves the CYP2E1-dependent lipid peroxide formation, either directly by its capability to induce NADPH-dependent peroxidation in the microsomal membranes or indirectly by a hypoxia-mediated transformation of xanthine dehydrogenase to xanthine oxidase, in activation of Ito cells and Kupffer cells to yield cytokine and collagen production. The CYP2E1 gene is polymorphic among Caucasians. Four different unrelated or partially linked polymorphisms have been observed. One polymorphism in the 5'-flanking region has been described to be associated with altered enzyme expression in vitro, and the rare allele was found to be less frequent among Swedish patients having lung cancer when compared to two different control groups. Another polymorphism, detectable with Dra I restriction endonuclease fragment length polymorphism (RFLP), was localized to intron 6, and the rare allele was less common among Italian alcoholics with clinical signs of liver cirrhosis, as compared to controls. Several other mutations in the CYP2E1 gene were found to be associated with this allele. However, further research is needed to relate the CYP2E1 gene polymorphism with incidence of liver cirrhosis.
...
PMID:Ethanol-inducible cytochrome P4502E1: genetic polymorphism, regulation, and possible role in the etiology of alcohol-induced liver disease. 812 98

The DNA fragmentation, a parameter of apoptosis, in non-small (NSCLC) and small (SCLC) cell lung cancer cell lines (N231 and PC-9) was evaluated. The DNA fragmentation in SCLC lines, but not in NSCLC lines, was observed in overgrown cells without exposure to anticancer drugs. In etoposide (VP-16)-treated N231 but not PC-9 cells, DNA fragmentation continued to increase up to 42 h, and the increase was dependent on the concentration of VP-16. The endonuclease activity of VP-16-treated N231, but not PC-9, cells required both Ca2+ and Mg2+ for full activity. It was elevated in a time- and concentration-dependent manner. As this activity was not affected by addition of cycloheximide, the activation of the endonuclease activity without protein synthesis may be involved in VP-16-induced cytotoxicity in N231.
...
PMID:Apoptosis induced by etoposide in small-cell lung cancer cell lines. 830 12


1 2 3 4 5 Next >>

---