Browsing by Subject "3D cell culture"

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Open Access
Characterization of chemosensitivity profiles of breast cancer cell lınes, with and without stem cell like features = Kök-hücre özelliği olan ve olmayan meme kanseri hücre hatlarının ilaç hassasiyet profillerinin tanımlanması
(2014) Akbar, Muhammad Waqas
Breast cancer is the second most common cause of death worldwide from cancer due to complications with its diagnosis and resistance to therapy. Recent studies have shown that breast tumors when compared with other solid tumors also contain a subpopulation termed as cancer stem cells (CSCs). CSCs are hard to kill due to their therapy resistant capacities. These unharmed cells then result into relapse of tumor after treatment. Some established breast cancer cell lines also behave in similar fashion to CSCs in overall manner thus termed as CSC like cell lines. This study primarily focuses on characterizing CSC like cell lines from non CSC like cell lines based upon their gene expression and prediction of drugs which can target these groups separately. In this study two databases, Cancer Cell Line Encyclopedia (CCLE) and Cancer Genome Project (CGP), were used which contain gene expression data and drugs cytotoxicity data for most of the established cancer cell lines. Breast cancer cell lines gene expression data was used to predict two gene lists which can separate breast cancer cell lines into CSC like and non CSC like cell lines by in silico analysis. These gene lists were named as Patentable and Non Patentable. Additionally four drugs were predicted which can target CSC like group (Midostaurin and Elesclomol) and non CSC like group (Panobinostat and Lapatinib) separately. Later these findings were validated in vitro. Non Patentable gene list could not be validated due to low concordance with microarray data. On the other hand, Patentable gene list was validated and was found concordant with microarray data. Out of four selected drugs, Panobinostat and Lapatinib showed increased toxicity to non CSC like cell lines while only Midostaurin showed toxicity to CSC like cell lines. To investigate further that cell lines were grown in 3D cell culture conditions, to increase their stem cell like properties (stemness). But only one cell line MDA-MB-157 which was found as CSC like, showed expected behavior. Additionally this cell line increased resistance to Lapatinib and Panobinostat and became more sensitive to Midostaurin. Correlation analysis showed some genes as potential biomarkers for selected drugs. In conclusion, in this study various genes are proposed to differentiate CSC like cell lines from non CSC like cell lines. And Midostaurin can be potential drug to treat CSC like cells while Lapatinib and Panobinostat showed increased activity against non CSC like cell lines.
Open Access
Microfluidic chip-based systems for monitoring cancer therapy
(2022-12) Yılmaz, Eylül Gülşen
In tumor microenvironment, cancer cells are exposed to a range of fluid shear stresses (FSS); yet, current in vitro three-dimensional (3D) models have limitations to investigate the impact of biophysical stimuli on cancer mechanism and chemoresistance in a dynamic manner. In the past few decades, vital demand for exploring biological significance of mechanical forces has led to the development of several innovative approaches. One of these approaches is the integration of microfluidic systems into cancer studies. The use of microfluidic chips has garnered increasing attention since they offer ease-of-manipulation, high-throughput, less material/reagent consumption, and low-cost. On the other hand, the researches have stated explicitly that tumor-derived extracellular vesicles (EVs) regulate local and systemic milieu to drive the development and spread of cancer through nano- and micron-sized vesicles they carry. In this thesis, breast cancer cells (MCF-7) have been utilized as a model cancer system, and accordingly, they are cultivated through SF-coated microfluidic systems in order to mimic tumor microenvironment, exhibiting a more dynamic condition. Simultaneously, traditional static culture of MCF-7 cells is also performed as a control group in order to understand the impact of flow conditions. The effects of FSS on gene expression—in particular, EpCAM and CK-18 genes, which are highly expressed in MCF-7 cells— have been examined at the end of cell culturing process. In addition, cancer cells developing any resistance to anti-cancer drugs on the course of FSS have been investigated. In this regard, the cells are treated with either doxorubicin or docetaxel (anti-cancer drugs) in the cases of dynamic (microfluidic system) and static (tissue culture flask) culture conditions. Multi-Drug Resistance 1 (MDR-1) and Breast Cancer Resistance Protein (BCRP) gene expression levels have been assessed once anti-cancer treatment has been finalized. The final step of this study relies on the isolation and analysis of EVs from both static and dynamic conditions with the presence and absence of anti-cancer drug treatment. The utility of EVs has been evaluated deliberately as biomarkers for real-time monitoring of treatment efficacy.