Expression of a retrovirally transduced gene under control of an internal housekeeping gene promoter does not persist due to methylation and is restored partially by 5-azacytidine treatment
| Autor: | Toshiya Nakatani, Masaji Kikukawa, Takemi Sakamoto, Shigeki Kuriyama, Y. Toyokawa, Hiroshi Fukui, Kazuhiro Ikenaka, Hirohisa Tsujinoue, Tadasu Tsujii |
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| Rok vydání: | 1998 |
| Předmět: |
Antimetabolites
viruses Transgene Genetic enhancement Genetic Vectors Gene Expression Biology Transfection Thymidine Kinase Viral vector Mice chemistry.chemical_compound Liver Neoplasms Experimental Gene expression Genetics Animals Enzyme Inhibitors Promoter Regions Genetic Ganciclovir Molecular Biology Gene Promoter Genetic Therapy DNA Methylation Suicide gene Molecular biology Demethylating agent Blotting Southern Retroviridae chemistry Azacitidine Cancer research Molecular Medicine |
| Zdroj: | Gene Therapy. 5:1299-1305 |
| ISSN: | 1476-5462 0969-7128 |
| Popis: | Although expression of transgenes under the control of a retroviral long terminal repeat (LTR) promoter has been shown not to persist due to methylation, it has been observed that internal promoter may be active even if expression from the LTR promoter is silent. We constructed a retroviral vector carrying the herpes simplex virus thymidine kinase (HSVtk) gene under the control of the albumin gene promoter and transduced the HSVtk gene into hepatocellular carcinoma cells. Three of 14 mice, however, could not eradicate HSVtk-transduced grafts completely despite ganciclovir (GCV) treatment. These GCV-refractory cell lines exhibited resistance to GCV after recultivation. Subsequent Southern blot analysis revealed that the HSVtk gene was not deleted but extensively or completely methylated in GCV-refractory lines. Treatment with 5-azacytidine, a demethylating agent, partially restored the sensitivity of GCV-refractory lines to GCV. These results indicate that expression of retrovirally transduced gene may not persist in vivo due to methylation even when the gene is directed by an internal housekeeping gene promoter. These observations may also have important implications for future clinical applications of retrovirus-mediated gene therapy. |
| Databáze: | OpenAIRE |
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