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Please use this identifier to cite or link to this item:
http://ir.nhri.org.tw/handle/3990099045/2838
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| Title: | Novel mutation of topoisomerase I in rendering cells resistant to camptothecin |
| Authors: | Chang, JY;Liu, JF;Juang, SH;Liu, TW;Chen, LT |
| Contributors: | National Institute of Cancer Research |
| Abstract: | To identify mechanisms of camptothecin (CPT) resistance and the relationship between CPT-resistant cells and other anticancer agents, a CPT-resistant cell line (CPT30) and its partial revertant cell line (CPT30R) were established from a human nasopharyngeal carcinoma cell line (HONE-1). CPT30 and CPT30R cells displayed a 14- and 3.5-fold resistance to CPT compared with HONE-1 cells, respectively. The resistant and partial revertant cell lines showed cross-resistance to topotecan and increased sensitivity to cisplatin, carboplatin, and 1,3-bis(chloroethyl)-1-nitrosurea. The topoisomerase (Top) 1 catalytic activity of CPT30 and CPT30R cells was 30% and 200%, respectively, compared with that of HONE-1 cells. The expression of Top 1 protein and mRNA levels in CPT30 cells was 40% and 30% less than that in HONE-1 cells, respectively, whereas in CPT30R cells, the levels of Top 1 protein and mRNA were 50% and 20% higher, respectively, than that in HONE-1 cells. Both the resistant and revertant cell line whole-cell lysates demonstrated different levels of sensitivity to CPT in in vitro assays in comparison with that of HONE-1 cells. Furthermore, CPT exhibited 15- and 7-fold better binding affinity in stabilizing protein-linked DNA breaks in HONE-1 cells than in CPT30 and CPT30R cells, respectively. Direct DNA sequencing of the reverse transcription-PCR product and genomic DNA revealed a point mutation resulting in E418K mutation in the Top 1 of both CPT30 and CPT30R cells. Wild-type Top 1 RNA and genomic DNA were also detected in these two cell lines. A yeast system was used to examine whether this mutation could be responsible for CPT resistance. Our results showed that a single amino acid change (E418K) resulted in CPT resistance. Therefore, quantitative and qualitative changes in Top 1 were responsible for CPT resistance in CPT30 cells. CPT resistance in CPT30R cells was caused by mutation of Top 1. |
| Keywords: | Oncology |
| Date: | 2002-07-01 |
| Relation: | Cancer Research. 2002 Jul;62(13):3716-3721. |
| Link to: | http://cancerres.aacrjournals.org/cgi/content/abstract/62/13/3716 |
| JIF/Ranking 2023: | http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=NHRI&SrcApp=NHRI_IR&KeyISSN=0008-5472&DestApp=IC2JCR |
| Cited Times(WOS): | https://www.webofscience.com/wos/woscc/full-record/WOS:000176579500026 |
| Cited Times(Scopus): | http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=0036644899 |
| Appears in Collections: | [陳立宗] 期刊論文
[劉滄梧] 期刊論文
[張俊彥] 期刊論文
[莊聲宏(1997-2004)] 期刊論文
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| 000176579500026.pdf | | 175Kb | Adobe PDF | 987 | View/Open |
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