E-Thesis 112 views
Novel Multiple Endpoint Approaches for Assessing Genotoxicity and Carcinogenicity Potential In Vitro / Linda Reilly
Swansea University Author: Linda Reilly
DOI (Published version): 10.23889/SUthesis.68029
Abstract
The current limitations of in vitro genotoxicity testing, often resulting in misleading predictions of in vivo carcinogenic potential, prompted a project aimed at enhancing predictive accuracy. This study integrated traditional genotoxicity data with a multi-endpoint approach, encompassing various c...
| Published: |
Swansea, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Jenkins, Gareth J. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa68029 |
| Abstract: |
The current limitations of in vitro genotoxicity testing, often resulting in misleading predictions of in vivo carcinogenic potential, prompted a project aimed at enhancing predictive accuracy. This study integrated traditional genotoxicity data with a multi-endpoint approach, encompassing various cellular endpoints relevant to carcinogenicity. The developed multi-endpoint testing platform was compared with an innovative Multi-Endpoint Genotoxicity Assessment (MEGA) screen, an automated imaging-based micronucleus assay in A549 cells, providing insights into genotoxic mechanisms. The Swansea-based multi-endpoint platform conducted assays, including cytotoxicity, micronuclei induction (Mn), cell cycle perturbations, and other cancer-related endpoints over time in TK6 and A549 cells. A group of compounds (Cisplatin, Temozolomide, Trichostatin A, Potassium Bromate) underwent assessment across both cell lines. Examining Cisplatin as an example, the multi-endpoint strategy revealed a significant increase in Mn at 4 µM (*P ≤ 0.05), 50% cytotoxicity at 6 µM, early (*P ≤ 0.05) and late-stage (**P ≤ 0.01) apoptosis at 6 µM, and G2/M arrest (****P ≤ 0.0001) at 4 µM after 24 hours with a 24-hour recovery in TK6 cells. In A549 cells, the same time point exhibited a significant Mn increase at 0.5µM (*P ≤ 0.05), 50% cytotoxicity at 3 µM, early-stage apoptosis (*P ≤ 0.05) at 3 µM, and an increase in G1 population (*P ≤ 0.05) starting at 0.5µM. In the MEGA screen, A549 cells demonstrated responses at substantially higher doses (1000 µM), accompanied by significant toxicity. A multiple endpoint approach provided a comprehensive understanding of cisplatin's mechanism of action. Concurrent evaluation of both multi-endpoint systems identified strengths and weaknesses, facilitating the development and refinement of a predictive testing platform for in vitro carcinogenicity assessment. Future exploration of multi-endpoint approaches promises insights into compound mechanisms of action, detection of safety concerns, and contributions to evolving regulatory standards. |
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| Item Description: |
A selection of third party content is redacted or is partially redacted from this thesis due to copyright restrictions. |
| Keywords: |
Genetic Toxicology, Carcinogenicity, In Vitro Approaches |
| College: |
Faculty of Medicine, Health and Life Sciences |
| Funders: |
Medical Research Council, Integrative Toxicology Training Partnership |