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Optimization of proces for detection of free tumor DNA in plasma and its clinical utility for colorectal cancer, lung cancer and pancreatic cancer patients
Belšánová, Barbora ; Benešová, Lucie (advisor) ; Tachezy, Ruth (referee)
In current days, examination of circulating tumor DNA (ctDNA) finds new use across different cancers. It is directed at tumor-derived short fragments of DNA present in peripheral blood of patiens (mainly in advanced stages). Due to its minimal invasivity, almost 100 % specificity and relatively high sensitivity in stage IV patients, this approch found its main potential clinical utility especially in early detection of disease relapse or progression after tumor resection (i.e. post-operative follow-up), prediction and monitoring of therapy response and estimation of prognosis. As a result of minute levels of ctDNA on a high background of other non-tumor DNA fragments present in plasma, a suitable method exhibiting highest sensitivity is the key for proper detection of this marker. The approach is predominantly based on initial identification of a mutation in tumor tissue and its subsequent detection in plasma. The present work is aimed at optimization of ctDNA isolation and method of its detection based on PCR amplification followed by heteroduplex analysis by denaturing capillary electrophoresis (DCE) to achieve highest sensitivity for detection of mutated fraction in plasma sample. I have applied the optimized protocol to examine ctDNA in three types of cancers, namely colorectal cancer (122...
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Long-term monitoring of ctDNA levels in patients with metastatic colorectal cancer for early detection of progression or recurrence of the disease
Kopalová, Dominika ; Benešová, Lucie (advisor) ; Kološtová, Katarína (referee)
Circulating tumor DNA (ctDNA) in peripheral blood of patients with metastatic colorectal cancer appears to be a promising molecular marker that provides various applications. ctDNA levels vary depending on the presence, alternatively on the volume of tumor mass within patient's body, which can be used primarily for early detection of disease progression or recurrence and moreover for evaluating radicality of surgical treatment, all within long-term postoperative follow-up of the patient. Due to minimal invasivity of ctDNA analysis from peripheral blood (so-called liquid biopsy), it is possible to perform it repeatedly at relatively short time intervals. On account of very low fraction of ctDNA in total cell-free DNA (cfDNA) ranging between units and hundreds of percent, the key factor is optimal methodology covering all steps from the isolation process to a sufficiently sensitive detection technology. In this thesis I focus on an optimization of isolation process and analysis of ctDNA obtained from tumor tissue and plasma of selected patients with metastatic colorectal cancer in connection with surgical radicality and correlation with a clinical status of the patients.
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Circulating tumor DNA in advanced colorectal carcinoma patients
Kopalová, Dominika ; Benešová, Lucie (advisor) ; Saláková, Martina (referee)
Colorectal carcinoma (CRC) is worldwide known as one of the most often tumor diseases. Approximately 50 % of patients are diagnosed with advanced stage of CRC and moreover even after removing all of the tumor bearings, there is high risk of its recurrence. As most of others solid tumors the CRC also releases fragments of DNA also known as the circulating tumor DNA (ctDNA). The ctDNA analysis is a new tool for monitoring continuous tumor burden and for observing treatment response. Due to its minimal invasivity and high specificity is suitable for instance for long period postoperative follow-up of patients with CRC. Within the long period follow-up process an evaluation radicality of operation is conducted as well as an early detection of new tumor foci. This thesis focus on an origin and releasing mechanism of ctDNA into bloodstream, its features and clinical utility options for patients with an advanced colorectal carcinoma. Key words: circulating tumor DNA, ctDNA, advanced colorectal carcinoma, mCRC, marker
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Optimization of proces for detection of free tumor DNA in plasma and its clinical utility for colorectal cancer, lung cancer and pancreatic cancer patients
Belšánová, Barbora ; Benešová, Lucie (advisor) ; Tachezy, Ruth (referee)
In current days, examination of circulating tumor DNA (ctDNA) finds new use across different cancers. It is directed at tumor-derived short fragments of DNA present in peripheral blood of patiens (mainly in advanced stages). Due to its minimal invasivity, almost 100 % specificity and relatively high sensitivity in stage IV patients, this approch found its main potential clinical utility especially in early detection of disease relapse or progression after tumor resection (i.e. post-operative follow-up), prediction and monitoring of therapy response and estimation of prognosis. As a result of minute levels of ctDNA on a high background of other non-tumor DNA fragments present in plasma, a suitable method exhibiting highest sensitivity is the key for proper detection of this marker. The approach is predominantly based on initial identification of a mutation in tumor tissue and its subsequent detection in plasma. The present work is aimed at optimization of ctDNA isolation and method of its detection based on PCR amplification followed by heteroduplex analysis by denaturing capillary electrophoresis (DCE) to achieve highest sensitivity for detection of mutated fraction in plasma sample. I have applied the optimized protocol to examine ctDNA in three types of cancers, namely colorectal cancer (122...
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Development and validation of a new method for enrichment and detection of circulating tumor DNA in cancer patients
Pláničková, Lenka ; Minárik, Marek (advisor) ; Kuthan, Martin (referee)
Tumors are one of the leading causes of death worldwide. Generally, the prognosis is better if the treatment begins at an early stage. Nowadays, the conventional chemotherapy treatment of cancer, known for its limited efficacy and side effects, is being gradually replaced by targeted biological treatment, which is used when specific genetic mutations are found. A part of the treatment is a detection of a potential progression, which is mainly based on the tumor biomarkers monitoring. Currently, further investigation of a so-called liquid biopsy method are ongoing, on which this thesis is focused. The main aim of this work was the experimental development and validation of the method for detection of the ctDNA in the plasma samples based on the somatic mutations presence. For the development and optimization of the system on the principle of denaturation capillary electrophoresis, the samples of cancer patients with KRAS mutation were used. Subsequently, a clinical part of the research was performed on a pilot set of 21 plasma samples. Finally, the method was optimized for the detection of BRAF and EGFR markers. A partial objective was to improve the detection sensitivity and increase the capture of the ctDNA in patients with advanced stage of the disease. The results of this work suggest the...
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