Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells
We have investigated the processing of site-specific Pt−DNA cross-links in live mammalian cells to enhance our understanding of the mechanism of action of platinum-based anticancer drugs. The activity of platinum drugs against cancer is mediated by a combination of processes including cell entry, dr...
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| Format: | Article |
| Language: | en_US |
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American Chemical Society
2011
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| Online Access: | http://hdl.handle.net/1721.1/64756 https://orcid.org/0000-0002-2693-4982 |
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| author | Ang, Wee Han Myint, MyatNoeZin Lippard, Stephen J. |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Ang, Wee Han Myint, MyatNoeZin Lippard, Stephen J. |
| author_sort | Ang, Wee Han |
| collection | MIT |
| description | We have investigated the processing of site-specific Pt−DNA cross-links in live mammalian cells to enhance our understanding of the mechanism of action of platinum-based anticancer drugs. The activity of platinum drugs against cancer is mediated by a combination of processes including cell entry, drug activation, DNA-binding, and transcription inhibition. These drugs bind nuclear DNA to form Pt−DNA cross-links, which arrest key cellular functions, including transcription, and trigger a variety of responses, such as repair. Mechanistic investigations into the processing of specific Pt−DNA cross-links are critical for understanding the effects of platinum−DNA damage, but conventional in vitro techniques do not adequately account for the complex and intricate environment within a live cell. With this limitation in mind, we developed a strategy to study platinum cross-links on plasmid DNAs transfected into live mammalian cells based on luciferase reporter vectors containing defined platinum−DNA lesions that are either globally or site-specifically incorporated. Using cells with either competent or deficient nucleotide excision repair systems, we demonstrate that Pt−DNA cross-links impede transcription by blocking passage of the RNA polymerase complex and that nucleotide excision repair can remove the block and restore transcription. Results are presented for 3800-base pair plasmids that are either globally platinated or carry a single 1,2-d(GpG) or 1,3-d(GpTpG) intrastrand cross-link formed by either cis-{Pt(NH3)2}2+ or cis-{Pt(R,R-dach)}2+, where {Pt(NH3)2}2+ is the platinum unit conveyed by cisplatin and carboplatin and R,R-dach is the oxaliplatin ligand, R,R-1,2-diaminocyclohexane. |
| first_indexed | 2024-09-23T09:57:00Z |
| format | Article |
| id | mit-1721.1/64756 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:57:00Z |
| publishDate | 2011 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | mit-1721.1/647562022-09-30T17:54:24Z Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells Ang, Wee Han Myint, MyatNoeZin Lippard, Stephen J. Massachusetts Institute of Technology. Department of Chemistry Lippard, Stephen J. Lippard, Stephen J. Ang, Wee Han Myint, MyatNoeZin We have investigated the processing of site-specific Pt−DNA cross-links in live mammalian cells to enhance our understanding of the mechanism of action of platinum-based anticancer drugs. The activity of platinum drugs against cancer is mediated by a combination of processes including cell entry, drug activation, DNA-binding, and transcription inhibition. These drugs bind nuclear DNA to form Pt−DNA cross-links, which arrest key cellular functions, including transcription, and trigger a variety of responses, such as repair. Mechanistic investigations into the processing of specific Pt−DNA cross-links are critical for understanding the effects of platinum−DNA damage, but conventional in vitro techniques do not adequately account for the complex and intricate environment within a live cell. With this limitation in mind, we developed a strategy to study platinum cross-links on plasmid DNAs transfected into live mammalian cells based on luciferase reporter vectors containing defined platinum−DNA lesions that are either globally or site-specifically incorporated. Using cells with either competent or deficient nucleotide excision repair systems, we demonstrate that Pt−DNA cross-links impede transcription by blocking passage of the RNA polymerase complex and that nucleotide excision repair can remove the block and restore transcription. Results are presented for 3800-base pair plasmids that are either globally platinated or carry a single 1,2-d(GpG) or 1,3-d(GpTpG) intrastrand cross-link formed by either cis-{Pt(NH3)2}2+ or cis-{Pt(R,R-dach)}2+, where {Pt(NH3)2}2+ is the platinum unit conveyed by cisplatin and carboplatin and R,R-dach is the oxaliplatin ligand, R,R-1,2-diaminocyclohexane. National Cancer Institute (U.S.) (grant CA032134) National University of Singapore (Overseas Postdoctoral Fellowship) 2011-07-07T14:06:47Z 2011-07-07T14:06:47Z 2010-05 Article http://purl.org/eprint/type/JournalArticle 0002-7863 1520-5126 http://hdl.handle.net/1721.1/64756 Ang, Wee Han, MyatNoeZin Myint, and Stephen J. Lippard. “Transcription Inhibition by Platinum−DNA Cross-Links in Live Mammalian Cells.” Journal of the American Chemical Society 132.21 (2010) : 7429-7435. https://orcid.org/0000-0002-2693-4982 en_US http://dx.doi.org/10.1021/ja101495v Journal of the American Chemical Society Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society Prof. Lippard via Erja Kajosalo |
| spellingShingle | Ang, Wee Han Myint, MyatNoeZin Lippard, Stephen J. Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells |
| title | Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells |
| title_full | Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells |
| title_fullStr | Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells |
| title_full_unstemmed | Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells |
| title_short | Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells |
| title_sort | transcription inhibition by platinum dna cross links in live mammalian cells |
| url | http://hdl.handle.net/1721.1/64756 https://orcid.org/0000-0002-2693-4982 |
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