Carcinogen-induced DNA amplification in vitro: overreplication of the simian virus 40 origin region in extracts from carcinogen-treated CO60 cells
| Autor: | Shulamit Karby, D Hassin, Sara Lavi, Y Berko-Flint |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
DNA Replication
Methylnitronitrosoguanidine Antigens Polyomavirus Transforming Restriction Mapping Simian virus 40 In Vitro Techniques Biology Virus Replication Virus chemistry.chemical_compound Cricetulus Plasmid Antigen Cricetinae Tumor Cells Cultured Animals Molecular Biology Dose-Response Relationship Drug DNA synthesis Gene Amplification Cell Biology Molecular biology In vitro chemistry Viral replication Cell culture DNA Viral DNA Research Article DNA Damage HeLa Cells Transcription Factors |
| Zdroj: | Molecular and Cellular Biology. 10:75-83 |
| ISSN: | 1098-5549 0270-7306 |
| DOI: | 10.1128/mcb.10.1.75 |
| Popis: | An in vitro system to study carcinogen-induced amplification in simian virus 40 (SV40)-transformed Chinese hamster (CO60) cells is described. SV40 amplification in this system resembled in many aspects the viral overreplication observed in drug-treated CO60 cells. Cytosolic extracts from N-methyl-N'-nitro-N-nitrosoguanidine-treated cells supported de novo DNA synthesis in the presence of excess exogenous T antigen and the SV40-containing plasmid pSVK1. The pattern of viral replication in these extracts was unique, since only the 2.4-kilobase-pair region spanning the origin was overreplicated, whereas distal sequences were not replicated significantly. Extracts from control cells supported only marginal levels of replication. In HeLa extracts, complete SV40 DNA molecules were replicated efficiently. The overreplication of the origin region in CO60 cell extracts was bidirectional and symmetrical. A fraction of the newly synthesized DNA molecules underwent a second round of replication, yielding MboI-sensitive fragments representing the 2.4-kilobase-pair region around the origin. The mechanisms controlling the amplification of the viral origin region, the nature of the cellular factors induced in the carcinogen-treated cells, and their putative association with general drug-induced SOS-like responses are discussed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|