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Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy

Platinum-based drugs are an important group of alkylating-like agents which are used in cancer chemotherapy treatment. Cisplatin and oxaliplatin in particular are still commonly used today and are the focus of this thesis. As with most chemotherapy drugs, the efficacy of these drugs are limited by t...

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Main Author: Sarah E. Taylor
Format: Default Thesis
Published: 2014
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Online Access:https://hdl.handle.net/2134/17448
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author Sarah E. Taylor
author_facet Sarah E. Taylor
author_sort Sarah E. Taylor (7163414)
collection Figshare
description Platinum-based drugs are an important group of alkylating-like agents which are used in cancer chemotherapy treatment. Cisplatin and oxaliplatin in particular are still commonly used today and are the focus of this thesis. As with most chemotherapy drugs, the efficacy of these drugs are limited by toxicity as well as tumour resistance, and therefore by increasing our understanding of these areas it is hoped to one day achieve personalised chemotherapy. The use of ICP-MS in the study of bio-sciences is still relatively new, however it has the ability to provide robust, fast and accurate methods for the quantification of platinum in biological samples. The research presented here utilised mass spectrometry in the study of the formation of Pt-DNA adducts in the clinical samples, the binding of oxaliplatin to short peptides and the effect of selenium supplementation on oxaliplatin in colorectal cancer cell lines. A comparison in the number of Pt-DNA adducts in saliva and leukocyte samples obtained from patients undergoing Pt-based chemotherapy demonstrated a lack of correlation between the two sample types. Samples were taken pre- and post-treatment and analysed via SF-ICP-MS and significant inter-patient variability was observed as expected. In both leukocyte and saliva samples, not only was Pt from previous chemotherapy cycles observed, but Pt was detected in the DNA in both sample types 1 hour after treatment. However a lack of correlation between platinum levels seen in the blood and saliva, combined with unexpected difficulties obtaining patient adherence to the saliva sampling protocol, indicated that saliva does not at present offer a reliable alternative to leukocytes for this assay. The binding of oxaliplatin to short nitrogen and sulfur rich peptides was investigated. Platinum binding to the peptides was observed and no significant differences in the level of binding were observed between the range of N and S rich peptides studied in this investigation. Partly due to the inability to reproduce biological conditions in this study, oxaliplatin was observed as a whole molecule, and furthermore dimers and multimers were also observed. The effect of selenium supplementation on the total cellular uptake of platinum was investigated in cultured cells via ICP-MS and LA-ICP-MS. It was observed that selenium decreased the amount of Pt taken up by the cancer cells. This was seen in analysis of populations of cells as well as by single cell analysis. Furthermore, while problems were encountered measuring selenium in subcellular experiments, the effect of selenium on the subcellular distribution of platinum as well as the number of Pt-DNA adducts could be determined.
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spelling rr-article-93987232014-01-01T00:00:00Z Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy Sarah E. Taylor (7163414) Other chemical sciences not elsewhere classified Pt-based drugs Oxaliplatin Cisplatin Pt-DNA Adducts Platinum Selenium MSA Clinical samples Cell culture ICP-MS ESI-MS Chemical Sciences not elsewhere classified Platinum-based drugs are an important group of alkylating-like agents which are used in cancer chemotherapy treatment. Cisplatin and oxaliplatin in particular are still commonly used today and are the focus of this thesis. As with most chemotherapy drugs, the efficacy of these drugs are limited by toxicity as well as tumour resistance, and therefore by increasing our understanding of these areas it is hoped to one day achieve personalised chemotherapy. The use of ICP-MS in the study of bio-sciences is still relatively new, however it has the ability to provide robust, fast and accurate methods for the quantification of platinum in biological samples. The research presented here utilised mass spectrometry in the study of the formation of Pt-DNA adducts in the clinical samples, the binding of oxaliplatin to short peptides and the effect of selenium supplementation on oxaliplatin in colorectal cancer cell lines. A comparison in the number of Pt-DNA adducts in saliva and leukocyte samples obtained from patients undergoing Pt-based chemotherapy demonstrated a lack of correlation between the two sample types. Samples were taken pre- and post-treatment and analysed via SF-ICP-MS and significant inter-patient variability was observed as expected. In both leukocyte and saliva samples, not only was Pt from previous chemotherapy cycles observed, but Pt was detected in the DNA in both sample types 1 hour after treatment. However a lack of correlation between platinum levels seen in the blood and saliva, combined with unexpected difficulties obtaining patient adherence to the saliva sampling protocol, indicated that saliva does not at present offer a reliable alternative to leukocytes for this assay. The binding of oxaliplatin to short nitrogen and sulfur rich peptides was investigated. Platinum binding to the peptides was observed and no significant differences in the level of binding were observed between the range of N and S rich peptides studied in this investigation. Partly due to the inability to reproduce biological conditions in this study, oxaliplatin was observed as a whole molecule, and furthermore dimers and multimers were also observed. The effect of selenium supplementation on the total cellular uptake of platinum was investigated in cultured cells via ICP-MS and LA-ICP-MS. It was observed that selenium decreased the amount of Pt taken up by the cancer cells. This was seen in analysis of populations of cells as well as by single cell analysis. Furthermore, while problems were encountered measuring selenium in subcellular experiments, the effect of selenium on the subcellular distribution of platinum as well as the number of Pt-DNA adducts could be determined. 2014-01-01T00:00:00Z Text Thesis 2134/17448 https://figshare.com/articles/thesis/Mass_spectrometric_studies_of_the_biological_fate_of_platinum-based_drugs_and_selenium_supplementation_in_cancer_chemotherapy/9398723 CC BY-NC-ND 4.0
spellingShingle Other chemical sciences not elsewhere classified
Pt-based drugs
Oxaliplatin
Cisplatin
Pt-DNA Adducts
Platinum
Selenium
MSA
Clinical samples
Cell culture
ICP-MS
ESI-MS
Chemical Sciences not elsewhere classified
Sarah E. Taylor
Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
title Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
title_full Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
title_fullStr Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
title_full_unstemmed Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
title_short Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
title_sort mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy
topic Other chemical sciences not elsewhere classified
Pt-based drugs
Oxaliplatin
Cisplatin
Pt-DNA Adducts
Platinum
Selenium
MSA
Clinical samples
Cell culture
ICP-MS
ESI-MS
Chemical Sciences not elsewhere classified
url https://hdl.handle.net/2134/17448