Browsing by Subject "lung cancer"
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(2022)Despite recent advances in immunotherapies for lung cancer, their success is still hindered by limited predictability of treatment outcomes in patients, as well as by resistance-conveying tumor mutations such as EGFR. Moreover, due to the vast number of treatment options and their cost, a quick, reliable, and cost-efficient drug screening platform is needed to select the optimal treatments for each individual patient. This thesis focuses on finding the best culture conditions to be used in such a future platform, employing 3D cell cultures and microfluidics to mimic in vivo tumors while saving costs and allowing for high-throughput screening. Image-based analysis showed that culture medium can have significant impacts on both cancer organoid growth and morphology, as well as drug sensitivity to the EGFR-inhibiting drug Osimertinib. Specific medium factors, such as the antioxidant N-acetylcysteine, might be particularly important for the integrity of 3D structures in the platform and help prevent conversion to an adherent morphology. Moreover, flow cytometry analysis of immune cells from pleural effusion samples indicated that medium composition might facilitate creating an inflammatory environment in the platform, and that immune cells should not be cultured longer than one week to maximize their activity. Finally, this thesis compares two microfluidic devices for their suitability to be used in future high-throughput drug-screening applications, by contrasting their ease of handling, applicability in fluorescent imaging-based readouts, and possibility to mimic and study the tumor microenvironment in vitro. The results suggest that the choice of microfluidic device will be dependent on whether microscopy analysis or cell viability assays will be used as the main readout of the drug screening in the future.
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(2023)Lung cancer is the deadliest cancer in the world. Only 15-20% of patients that have been diagnosed is still alive after five years. Even though mortality in other types of cancer have become better in Finland the mortality in lung cancer has only become slightly better. A reason behind the bad prognosis is that lung cancer symptoms can be very non-specific and sometimes be completely absent. This leads to a diagnose in a late stage where the cancer has already created metastases. Lung cancer screening in a group of high-risk individuals with computer tomography has been proven to better the prognosis and lessen the mortality. To determine this group of individuals suitable for screening a number of risk-prediction models have been proposed. In recent years. The aim of this systematic review is to find externally validated models that predict the risk of lung cancer and could be used in a clinical setting in a primary healthcare level in Finland. The model should be able to identify a high-risk group of individuals for screening of lung cancer with computed tomography. An ideal model would be able to aid diagnosis of lung cancer at an early stage in a cost-effective way.
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(2023)Lung cancer, the current leading cause of death by cancer, can be categorized into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), lung adenocarcinoma of NSCLC being the most common. Advances have been made in lung adenocarcinoma treatment based on the tumor genetic profile, especially with epidermal growth receptor (EGFR) gene mutated lung cancers. The initial responses of targeted therapy have promising outcomes, but the patients acquire drug resistance against the selective EGFR tyrosine kinase inhibitors (TKIs), such as osimertinib. To find a way to prevent, revert, or bypass various EGFR TKI resistance mechanisms, they are studied in hopes of discovering new ways to inhibit or degrade EGFR, to target the bypass mechanisms, or tumor heterogeneity. This study aims to target intratumor heterogeneity of EGFR expression to prevent Osimertinib resistance/enhance Osimertinib efficacy in PC9 cells. It was detected that PC9 cells were a heterogeneous population, that could be separated into EGFR-low expressing and EGFR-high expressing cells. Based on clustered regularly interspaced short palindromic repeats (CRISPR) screening, EGFR-low cells had enriched expression of Ariadne RBR E3 Ubiquitin Protein Ligase 2 (ARIH2) and RING finger protein 7 (RNF7) genes compared to EGFR-high cells. These genes encode proteins that are part of a ubiquitylation complex E3-E3 ligase, possibly mediating proteasomal degradation of EGFR. To verify this, the genes are first knocked out (KO) in PC9 EGFR-low cells with CRISPR-Cas9 method. Second, parental cells are treated with pevonedistat, which is an E3-E3 ligase activator inhibitor. The effects of ARIH2/RNF7 KO cells, and pevonedistat-treated cells are analyzed with flow cytometry. Lastly, an in vitro drug experiment to see, if the combination of osimertinib and pevonedistat would have a synergistic effect in killing PC9 EGFR-low cells. RNF7 KO cells and pevonedistat-treated cells appeared to have elevated levels of EGFR, insinuating EGFR is proteasomally degraded by E3-E3 ligase. The results of in vitro drug experiment looked promising as the combination drug treatment seemed to be the most effective. The E3-E3 ligase is an appealing target for cancer therapy but it has not been researched much in lung cancer context. Also, pevonedistat is still on clinical trials and has cytotoxic effects, therefore, the proteasomal degradation pathway of EGFR requires to be more studied.
Now showing items 1-3 of 3