Ahmad, Rozaina (2018) Gene And Protein Analyses Of Selected Drug-resistan Breast Cancer Cell Lines Treated With Thymoquinone-nanoparticle. Masters thesis, Universiti Sains Malaysia.
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Abstract
Chemotherapy is an important option for the treatment of breast cancer. Nevertheless, drug resistance is one of the major obstacles. There is a need to address this challenge with a new drug using nanotechnology. Nanomedicine is used for drug delivery in the current cancer therapy. Free thymoquinone (TQ) is a potential active compound of Nigella sativa seed extract that exhibits medicinal value. Therefore, present study aimed to synthesise and characterise the TQ encapsulated poly (d 1- lactide-co-glycolide) polyethylene glycol (PLGA-PEG) nanoparticles to conserve its bioavailability and also to develop MCF-7 cell line resistance to tamoxifen (TAМ). Subsequently, the resistance breast cancer cell line were treated with TQ-nanoparticle to determine the modulation of targeted protein, and gene expression. TQnanoparticles were prepared by solvent displacement technique.It was then characterised with different techniques which involved Transmission Electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-VIS), dynamic light scattering (DLS), attenuated total reflectance infrared (ATR-IR), entrapment efficiency and drug release analysis. In this study, two type of breast cancer cell lines are used which were MCF-7 and UACC 732 to study effectiveness of TQnanoparticle. The MCF-7 is estrogen receptor positive (ER +) cell line from the luminal A subtype. Development of Tamoxifen (TAM) resistance MCF-7 was done using pulse method. Resistance index was determined after treatment with TAM using MTS assay. The UACC-732 cell line is human epidermal growth factor receptor 2 (HER2) overexpress and resistance to trastuzumab and lapatinib. Genetic and proteomic modulation caused by TQ-nanoparticles in drug-resistant cancer subtypes were investigated. TQ-nanoparticle structure characterisation by DLS and TEM revealed particle diameter between 50-100 nm. Zeta potential estimation revealed that the TQ-nanoparticle formulations were negatively charged (-25 mV). This would confer facilitated cellular uptake. The success of drug encapsulation within polymer was confirmed with ATR-IR technique. Encapsulation efficiency of TQ was 79.9% and drug release showed a maximum release of TQ at 50.3 %. Development of drug resistant MCF-7 cells showed that the 8 µM TamR MCF-7 cells achieved the highest resistance index compared to parental MCF-7 and cells exposed to other concentrations. It was further supportted by proteomic analysis, in which MDR1 expression was significantly upregulated (p<0.05).Findings indicated TQnanoparticle significantly reduced expression of MDR1, HER2 and MRP4 protein in UACC 732 cell (p<0.05). Similarly, resistant TamR MCF-7 cells showed reduction in expression, however they were not significant (p>0.05). Gene expression analysis was done to compare effect of TQ-nanoparticles with doxorubicin. Study showed significant decrease in expression of two drug resistant genes (ABCC5 and HER2/ERBB2) and cancer proliferation gene (BCL2). In conclusion, this study show that TQ-nanoparticle based on PLGA-PEG can reduce the expression of drug resistant gene and protein. Application of TQ-nanoparticle potentially can be used as new treatment to HER2 breast cancer.
| Item Type: | Thesis (Masters) |
|---|---|
| Subjects: | R Medicine |
| Divisions: | Institut Perubatan & Pergigian Termaju (Advanced Medical & Dental Institute (AMDI)) > Thesis |
| Depositing User: | NOR HASHIMY BIN ABDULLAH |
| Date Deposited: | 16 Jul 2026 01:54 |
| Last Modified: | 16 Jul 2026 01:54 |
| URI: | http://eprints.usm.my/id/eprint/64656 |
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