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Characterization of a novel topoisomerase I mutation from a camptothecin-resistant human prostate cancer cell line.
Cancer Res. 2001 Mar 01; 61(5):1964-9.CR

Abstract

In this study, we characterized the structure and function of topoisomerase I (top1) protein in the camptothecin (CPT)-resistant prostate cancer cell lines, DU-145/RC0.1 and DU-145/RC1 (RC0.1 and RC1, respectively). Both of the cell lines were previously selected by continuous exposure to 9-nitro-CPT. The RC0.1 and RC1 cells have high cross-resistance to CPT derivatives including SN-38 and topotecan, but are not cross-resistant to the non-top1 inhibitors etoposide, doxorubicin, and vincristine. Although the top1 protein levels were not decreased in the resistant cells compared with the parental cells, CPT-induced DNA cleavage was markedly reduced in the RC0.1 and RC1 nuclear extracts. The resistant-cell-line nuclear extracts also demonstrated top1 catalytic activity and resistance to CPT, in in vitro assays. Reverse transcription-PCR products from the resistant cell lines were sequenced, and revealed a point mutation resulting in a R364H mutation in the top1 of both RC0.1 and RC1. No wild-type top1 RNA or genomic DNA was detected in the resistant cell lines. Using a purified recombinant R364H top1, we found that the R364H mutant top1 was CPT resistant and fully active. In the published top1 crystal structure, the R364H mutation is close to the catalytic tyrosine and other well-known mutations leading to CPT resistance.

Authors+Show Affiliations

Division of Basic Sciences, National Cancer Institute, NIH, Bethesda, Maryland 20892-4255, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11280753

Citation

Urasaki, Y, et al. "Characterization of a Novel Topoisomerase I Mutation From a Camptothecin-resistant Human Prostate Cancer Cell Line." Cancer Research, vol. 61, no. 5, 2001, pp. 1964-9.
Urasaki Y, Laco GS, Pourquier P, et al. Characterization of a novel topoisomerase I mutation from a camptothecin-resistant human prostate cancer cell line. Cancer Res. 2001;61(5):1964-9.
Urasaki, Y., Laco, G. S., Pourquier, P., Takebayashi, Y., Kohlhagen, G., Gioffre, C., Zhang, H., Chatterjee, D., Pantazis, P., & Pommier, Y. (2001). Characterization of a novel topoisomerase I mutation from a camptothecin-resistant human prostate cancer cell line. Cancer Research, 61(5), 1964-9.
Urasaki Y, et al. Characterization of a Novel Topoisomerase I Mutation From a Camptothecin-resistant Human Prostate Cancer Cell Line. Cancer Res. 2001 Mar 1;61(5):1964-9. PubMed PMID: 11280753.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of a novel topoisomerase I mutation from a camptothecin-resistant human prostate cancer cell line. AU - Urasaki,Y, AU - Laco,G S, AU - Pourquier,P, AU - Takebayashi,Y, AU - Kohlhagen,G, AU - Gioffre,C, AU - Zhang,H, AU - Chatterjee,D, AU - Pantazis,P, AU - Pommier,Y, PY - 2001/3/31/pubmed PY - 2001/4/21/medline PY - 2001/3/31/entrez SP - 1964 EP - 9 JF - Cancer research JO - Cancer Res VL - 61 IS - 5 N2 - In this study, we characterized the structure and function of topoisomerase I (top1) protein in the camptothecin (CPT)-resistant prostate cancer cell lines, DU-145/RC0.1 and DU-145/RC1 (RC0.1 and RC1, respectively). Both of the cell lines were previously selected by continuous exposure to 9-nitro-CPT. The RC0.1 and RC1 cells have high cross-resistance to CPT derivatives including SN-38 and topotecan, but are not cross-resistant to the non-top1 inhibitors etoposide, doxorubicin, and vincristine. Although the top1 protein levels were not decreased in the resistant cells compared with the parental cells, CPT-induced DNA cleavage was markedly reduced in the RC0.1 and RC1 nuclear extracts. The resistant-cell-line nuclear extracts also demonstrated top1 catalytic activity and resistance to CPT, in in vitro assays. Reverse transcription-PCR products from the resistant cell lines were sequenced, and revealed a point mutation resulting in a R364H mutation in the top1 of both RC0.1 and RC1. No wild-type top1 RNA or genomic DNA was detected in the resistant cell lines. Using a purified recombinant R364H top1, we found that the R364H mutant top1 was CPT resistant and fully active. In the published top1 crystal structure, the R364H mutation is close to the catalytic tyrosine and other well-known mutations leading to CPT resistance. SN - 0008-5472 UR - https://www.unboundmedicine.com/medline/citation/11280753/Characterization_of_a_novel_topoisomerase_I_mutation_from_a_camptothecin_resistant_human_prostate_cancer_cell_line_ L2 - http://cancerres.aacrjournals.org/cgi/pmidlookup?view=long&pmid=11280753 DB - PRIME DP - Unbound Medicine ER -