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Reversion of multidrug resistance in the P-glycoprotein-positive human pancreatic cell line (EPP85-181RDB) by introduction of a hammerhead ribozyme
| Content Provider | Paperity |
|---|---|
| Author | Scanlon, Kj Dietel, M. Holm, Ps |
| Abstract | A major problem in cytostatic treatment of many tumours is the development of multidrug resistance (MDR4). This is most often accompanied by the overexpression of a membrane transport protein, P-glycoprotein, and its encoding mRNA. In order to reverse the resistant phenotype in cell cultures, we constructed a specific hammerhead ribozyme possessing catalytic activity that cleaves the 3'-end of the GUC sequence in codon 880 of the mdr1 mRNA. We demonstrated that the constructed ribozyme is able to cleave a reduced substrate mdr1 mRNA at the GUC position under physiological conditions in a cell-free system. A DNA sequence encoding the ribozyme gene was then incorporated into a mammalian expression vector (pH beta APr-1 neo) and transfected into the human pancreatic carcinoma cell line EPP85-181RDB, which is resistant to daunorubicin and expresses the MDR phenotype. The expressed ribozyme decreased the level of mdr1 mRNA expression, inhibited the formation of P-glycoprotein and reduced the cell's resistance to daunorubicin dramatically; this means that the resistant cells were 1,600-fold more resistant than the parental cell line (EPP85-181P), whereas those cell clones that showed ribozyme expression were only 5.3-fold more resistant than the parental cell line. |
| Starting Page | 239 |
| Ending Page | 243 |
| File Format | HTM / HTML |
| ISSN | 15321827 |
| DOI | 10.1038/bjc.1994.286 |
| Journal | British Journal of Cancer |
| Volume Number | 70 |
| e-ISSN | 15321827 |
| Language | English |
| Publisher | Nature Publishing Group |
| Publisher Date | 1994-08-01 |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
| Subject | Cancer Research Oncology |
