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Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines
Dissertation (MSc)--University of Pretoria, 2020.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2020
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| _version_ | 1867613486603829248 |
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| access_status_str | Open Access |
| author2 | Visagie, M.H. (Michelle Helen) |
| author_browse | Visagie, M.H. (Michelle Helen) |
| author_facet | Visagie, M.H. (Michelle Helen) |
| collection | Thesis |
| dc_rights_str_mv | © 2020 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2020. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/76848 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:36:55.109Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/76848 Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines Visagie, M.H. (Michelle Helen) MOKGADIGWANGWA@GMAIL.COM Joubert, Annie M. Gwangwa, Mokgadi Violet UCTD Glutamine deprivation ROS mitochondrial membrane potential cell cycle SOD catalase Health sciences theses SDG-03 Health sciences theses SDG-17 Dissertation (MSc)--University of Pretoria, 2020. Tumourigenic cells utilize aberrant metabolic process that supports the biosynthetic requirements for hyperproliferation, survival and prolonged maintenance characterised by glucose metabolism to lactate dehydrogenase independent of oxygen availability (Warburg effect). In addition, tumourigenic cells exert increased glycolytic- and glutaminolytic activity in order to provide increased quantities of adenosine triphosphate. The aim of this research project was to investigate the influence of glutamine deprivation on proliferation, morphology, oxidative stress, mitochondrial membrane potential, cell cycle progression, antioxidant defences, deoxyribonucleic acid (DNA) damage, energy status, cell survival signaling and cell death induction in tumourigenic- and non-tumourigenic breast cell lines. In this study it was found that glutamine deprivation results in differential antiproliferative activity where the MCF-7 cell line was the most affected with decreased cell growth to 61% after 96 h of glutamine deprivation. Aberrant redox activity was most prominently observed in the MCF-7 cell line accompanied with biphasic mitochondrial membrane potential- and reactive oxygen species production. The MCF-7 cell line showed significant mitochondrial membrane depolarisation after 24 h and 96 h deprivation from glutamine (1.5- and 1.37 fold). Cell cycle progression analysis illustrated an increase in the amount of cells present in the S-phase in the MCF-7 cell line after 72 h of glutamine deprivation. The MDA-MB-231 cell line resulted in a significant increase in cells occupying the G2/M phase after 24 h of glutamine deprivation. Glutamine deprivation in the BT-20 cell line resulted in a significant increase in cells occupying G1 phase after 72 h of glutamine deprivation. The MCF-7 cell line demonstrated the least amount of viable cells when analysing apoptosis induction, when compared to the MDA-MB-231-, MCF-10A- and BT-20 cell lines after glutamine deprivation suggesting that the MCF-7 cell line is the most affected cell line. Analysis of antioxidant mechanism via superoxide dismutase (SOD) inhibition illustrated increased SOD activity in the MCF-7 cell line (9.1%) after 72 h of glutamine deprivation. Evaluation of catalase protein concentration indicated that the MCF-7 catalase expression increased to 1.28 fold after 24 h of glutamine deprivation when compared to cell propagated in complete growth medium. DNA damage was demonstrated by visualising the presence of fluorescent 8-hydroxydeoxyguanosine and showed that the MCF-7 cell line presented with significant 8-hydroxydeoxyguanosine staining. Survival signaling was also evaluated through visualising extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K) signaling which demonstrated increased ERK activation in the non-tumourigenic MCF-10A cell line and decreased PI3K activation. This study provides evidence that there are differential- and time-dependent responses in breast tumourigenic cells versus non-tumourigenic cells, to glutamine deprivation thus unraveling the crosstalk between glutamine deprivation, oxidative stress and cell death and different cell types will enable us to better understand the basics of tumour cell metabolism and thus develop therapeutics that provide promising pre-sensitization potential for chemotherapeutic agents. em2026 Physiology MSc Unrestricted SDG-03: Good health and well-being SDG-17: Partnerships for the goals 2020-11-04T15:10:04Z 2020-11-04T15:10:04Z 20/04/24 2019 Dissertation Gwangwa, MV 2019, Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/76848> A2020 http://hdl.handle.net/2263/76848 en © 2020 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Glutamine deprivation ROS mitochondrial membrane potential cell cycle SOD catalase Health sciences theses SDG-03 Health sciences theses SDG-17 Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| title | Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| title_full | Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| title_fullStr | Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| title_full_unstemmed | Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| title_short | Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| title_sort | effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines |
| topic | UCTD Glutamine deprivation ROS mitochondrial membrane potential cell cycle SOD catalase Health sciences theses SDG-03 Health sciences theses SDG-17 |
| url | http://hdl.handle.net/2263/76848 |