Overproduction of dihydrofolate reductase and gene amplification in methotrexate-resistant Chinese hamster ovary cells
| Autor: | A K Essani, W Salser, Wayne F. Flintoff, D Robertson, C R Nagainis, M K Weber |
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| Rok vydání: | 1982 |
| Předmět: |
Drug Resistance
Reductase Cricetulus Cricetinae Complementary DNA Dihydrofolate reductase Animals Selection Genetic Molecular Biology Gene Cells Cultured Southern blot chemistry.chemical_classification Base Sequence biology Chinese hamster ovary cell Ovary Gene Amplification DNA Restriction Enzymes Cell Biology Molecular biology Tetrahydrofolate Dehydrogenase Restriction enzyme Methotrexate Enzyme Genes Biochemistry chemistry Karyotyping biology.protein Female Research Article |
| Zdroj: | Molecular and Cellular Biology. 2:275-285 |
| ISSN: | 1098-5549 0270-7306 |
| Popis: | Stable isolates of Chinese hamster ovary cells that are highly resistant to methotrexate have been selected in a multistep selection process. Quantitative immunoprecipitations have indicated that these isolates synthesize dihydrofolate reductase at an elevated rate over its synthesis in sensitive cells. Restriction enzyme and Southern blot analyses with a murine reductase cDNA probe indicate that the highly resistant isolates contain amplifications of the dihydrofolate reductase gene number. Depending upon the parenteral line used to select these resistant cells, they overproduce either a wild-type enzyme or a structurally altered enzyme. Karyotype analysis shows that some of these isolates contain chromosomes with homogeneously staining regions whereas others do not contain such chromosomes. |
| Databáze: | OpenAIRE |
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