Establishing a cisplatin-resistant triple negative breast cancer spheroid model
| dc.contributor.advisor | Sekhoacha, Mamello | en_ZA |
| dc.contributor.advisor | Abrahams, Beynon | en_ZA |
| dc.contributor.advisor | Gouws, Chrisna | en_ZA |
| dc.contributor.author | Ngalonkulu, Ongeziwe | en_ZA |
| dc.date.accessioned | 2025-01-03T11:18:32Z | |
| dc.date.available | 2025-01-03T11:18:32Z | |
| dc.date.issued | 2024 | en_ZA |
| dc.description | Dissertation (M.Med.Sc.(Pharmacology))--University of the Free State, 2024 | en_ZA |
| dc.description.abstract | In cancer research, conventional two-dimensional (2D) cell cultures and animal studies are often used in studying the disease and efficacy of anticancer agents despite their failure to accurately replicate the complex 𝘪𝘯 𝘷𝘪𝘷𝘰 tumour microenvironment. 2D cultures lack the extracellular matrix production critical for 𝘪𝘯 𝘷𝘪𝘷𝘰-like cell behaviour, thereby jeopardizing data accuracy when developing effective cancer therapies and understanding mechanisms underlying drug resistance and cancer relapse. There is, therefore, a pressing need for models that accurately recapitulate 𝘪𝘯 𝘷𝘪𝘷𝘰 systems and enhance researchers’ accuracy in predicting disease mechanisms. This study aimed to establish a cisplatin-resistant three-dimensional (3D) spheroid model using the scaffold-free technique of rotating wall bioreactors in the CelVivo ClinoStar™ system, to facilitate efficient recapitulation of 𝘪𝘯 𝘷𝘪𝘷𝘰-like conditions and higher throughput. The MDA-MB-231 cell line is classified as triple negative breast cancer (TNBC) due to the absence of the oestrogen receptor and progesterone receptor, as well as the human epidermal growth factor receptor 2. As a result, the MDA-MB-231 cell line is characterized as a highly metastatic and aggressive cell line with a poor prognosis. Cisplatin-resistant MDA-MB-231 cells were generated by exposing the cell line to IC10-IC50 (0.01μM, 0.1μM, 1μM, 5μM and 10μM) concentrations of cisplatin for nine months. The cells acquired resistance; these resistant cells were then used to develop a 3D spheroid model. Characterization of the cisplatin-resistant MDA-MB-231 spheroids over 28 days included assessing spheroid growth and viability, and identifying the optimal experimental window between days 12 and 22. The model's reactivity to cisplatin and doxorubicin treatment was evaluated for 96 hour (h) to qualify the model for treatment screening. Treatment with the clinical cisplatin dose (4,435 x 10⁻⁶ μg cisplatin/μg protein) showed pronounced reactivity after 48 h, with decreased cell viability and increased cell death. However, spheroids recovered after 72-96 h, displaying moderate to high metabolic activity, typical of resistance. The IC₅₀ (8.06 x 10⁻² μg cisplatin/μg protein) dose of cisplatin demonstrated immediate effects on the model after 48 h, however, increase in spheroid size and decrease in cell death was observed with increased metabolic activity after apparent recovery at 72-96 h suggesting resistance. Treatment with doxorubicin clinical dose (1.064 x 10⁻⁵ μg dox/μg protein) had the most pronounced effect on the model throughout the 96 h and resulted in decreased spheroid size. It was apparent that the model was not as resistant to the doxorubicin treatment as it was to the cisplatin treatment. This model has potential for preclinical research studies as it displays reactivity to commonly used chemotherapeutic drugs and could be valuable in understanding drug-resistant cancer. In conclusion, the established cisplatin-resistant MDA-MB-231 3D spheroid model offers a robust platform for studying drug effects in TNBC research. | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/12900 | |
| dc.language.iso | en | |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | CelVivo ClinoStar™ | en_ZA |
| dc.subject | Cisplatin resistance | en_ZA |
| dc.subject | Spheroid model | en_ZA |
| dc.subject | Three-dimensional cell culture | en_ZA |
| dc.subject | Triple negative breast cancer | en_ZA |
| dc.subject | Two-dimensional cell culture | en_ZA |
| dc.title | Establishing a cisplatin-resistant triple negative breast cancer spheroid model | en_ZA |
| dc.type | Dissertation |