|
|
Molecular genetic analysis of thyroid carcinomas in pediatric and adolescent patients
Bulanová, Barbora ; Kuklíková, Vlasta (advisor) ; Ludvíková, Marie (referee) ; Vícha, Aleš (referee)
Thyroid nodules are rare in pediatric and adolescent patients, but they are at greater risk of malignancy than adult patients. Thyroid carcinomas are the most common endocrine malignancy and their incidence is increasing. Although there are several types of thyroid carcinoma, 90% of cases in pediatric and adolescent patients are papillary thyroid carcinomas (PTCs). The aim of this study was to analyze a large cohort of PTCs from pediatric and adolescent patients, determine their genetic cause, and correlate the findings with clinical pathological data. Another aim was to characterize the most frequent findings and compare them with a cohort of adult patients with thyroid carcinoma positive for the same mutation. The final objective was to optimize a suitable methodology for detecting the most common findings in pediatric and adolescent patients for routine use. Thyroid tumor tissue samples were examined using molecular genetic methods, mostly using next-generation sequencing and real-time PCR analysis. We found that fusion genes were the most common cause of PTC in pediatric and adolescent patients, detected in 56% of patients. In total, 20 different types of fusion genes were identified, some of which have not been previously described in the literature. The fusion genes included the oncogenes...
|
|
|
Molecular Genetic Analysis in Patients Suspected of Cryptic Rearrangements.
Šolc, Roman ; Hirschfeldová, Kateřina (advisor) ; Vícha, Aleš (referee)
Such chromosomal rearrangements, which cannot be detected by using of cytogenetic banding of metaphase chromosomes, i.e. chromosomes smaller than 3 - 5 Mb, and therefore modern molecular genetic methods are used to detect them, are called "cryptic rearrangements". Their important role in human pathology is more and more significant. By using of the multiplex ligation-probe dependent amplification method (MLPA) we examined a group of 50 probands with idiopathic mental retardation. A cryptic rearrangement was found at 8 probands (16 %), at 6 of them it was demonstrably causal. Then we examined a group of 40 probands suspected of gene SHOX pathology. A cryptic rearrangement was found at 17 probands (42.5 %) and at 8 of them it was demonstrably causal. Presence of small deletion founded isolated at 7 probands was verified in a population set, but without a positive result. An analysis of mutations was made too.
|
|
|
Human Diseases Caused by Germline Mutations of the Hedgehog Signaling Pathway
Trsová, Iva ; Křepelová, Anna (advisor) ; Vícha, Aleš (referee)
The Hedgehog signalling pathway is involved in regulation of differentiation of embryonic cells, in body patterning, in development of brain, bone, muscle, gastrointestinal tract, lungs, and in maintenance and regeneration of adult tissues. The pathway includes more than 10 proteins: receptors, coreceptors, ligands, transcription effectors and repressors, linked in complex functional interactions. Disruption of the hedgehog signalling during embryogenesis can lead to a serious developmental disorder - to holoprosencephaly. Loss-of- function mutations of PTCH1 lead to Gorlin syndrome - a hereditary predisposition to basal cell carcinoma associated with anomalies of brain, scull, vertebrae, and ribs. Both holoprosencephaly and Gorlin syndrome have been shown to be genetically heterogeneous, both can be caused by germline mutations of several genes of the Hedgehog signalling pathway. From 2006 to 2016, the PTCH1 gene was analysed for diagnostic purposes in 70 unrelated patients with suspicion of Gorlin syndrome (MIM 109400) referred to the Department of Biology and Medical Genetics, 2nd Medical School and University Hospital Motol, Prague. A pathogenic variant of the PTCH1 gene was detected in 35 (50%) of patients. No mutation was found in 35 patients, 10 of them fulfilled, and 25 of them did not...
|
|
|
Human Diseases Caused by Germline Mutations of the Hedgehog Signaling Pathway
Trsová, Iva ; Křepelová, Anna (advisor) ; Vícha, Aleš (referee)
The Hedgehog signalling pathway is involved in regulation of differentiation of embryonic cells, in body patterning, in development of brain, bone, muscle, gastrointestinal tract, lungs, and in maintenance and regeneration of adult tissues. The pathway includes more than 10 proteins: receptors, coreceptors, ligands, transcription effectors and repressors, linked in complex functional interactions. Disruption of the hedgehog signalling during embryogenesis can lead to a serious developmental disorder - to holoprosencephaly. Loss-of- function mutations of PTCH1 lead to Gorlin syndrome - a hereditary predisposition to basal cell carcinoma associated with anomalies of brain, scull, vertebrae, and ribs. Both holoprosencephaly and Gorlin syndrome have been shown to be genetically heterogeneous, both can be caused by germline mutations of several genes of the Hedgehog signalling pathway. From 2006 to 2016, the PTCH1 gene was analysed for diagnostic purposes in 70 unrelated patients with suspicion of Gorlin syndrome (MIM 109400) referred to the Department of Biology and Medical Genetics, 2nd Medical School and University Hospital Motol, Prague. A pathogenic variant of the PTCH1 gene was detected in 35 (50%) of patients. No mutation was found in 35 patients, 10 of them fulfilled, and 25 of them did not...
|
|
|
Characteristic of chromosomal changes in nephroblastomas using SNP array and MLPA
Štolová, Lucie ; Vícha, Aleš (advisor) ; Daňková, Pavlína (referee)
Nephroblastoma is the most prevalent pediatric kidney tumor, which occurs primarily in younger children with the average age at diagnosis of 42,5 months for girls and 36,5 months for boys. Even though its treatment is currently very succesful and the overall survival rate reaches over 90 %, there are still more things to be discovered and improved. An important role for the right choice of treatment plays not only the histology of tumor, but also the chromosomal changes present at tumor. Some of them (for example 1q gain, simultaneous deletion of 1p and 16q, TP53 deletion) were confirmed as negative prognostic markers because they are associated with an increased risk of relapse or with anaplastic type of nephroblastoma that is included in a high risk group. These changes are therefore used together with the tumor histology for stratification of nephroblastomas. Some of these changes were found in a heterogeneous state (only in a part of the cells) in nephroblastoma, which also complicates the treatment of the patient and which cannot be solved when only one sample is taken from the tumor. In this work we concentrated on the detection of chromosomal changes present in nephroblastomas of 44 patients and their associations with clinical data. We have proved some of the known associations (22q...
|
|
|
The use of molecular-biology methods (QRT-PCR) and immunocytological methods (flow cytometry and immunocytochemistry) for the detection of minimal residual disease in neuroblastoma
Grüncveigová, Veronika ; Vícha, Aleš (advisor) ; Daňková, Pavlína (referee)
With a continuous development of molecular-biology methods more attention has been paid to molecular detection of minimal residual diseases in solid tumors. In our study we focused on detection of MRD in neuroblastoma. Neuroblastoma is one of the peripheral neuroblastic tumors (pNTs) that accounts approximately for10 percent of all childhood cancers. The question raised however not answered until this day is whether evidence of MRD in bone marrow may be used as independent prognostic factor in diagnosis of neuroblastoma. Furthermore, it is important to establish what kind of testing technique should be used and what values to look at. There exist various methodologies in detection of MRD evidence in neuroblastoma. These methods differ in cost and complexity, but mainly some of them are more specific and sensitive than the other. Cancer cells may be detected in the blood as well as in the bone marrow. Very often it is the bone marrow that is affected by the metastasis in neuroblastoma, therefore 85% of all high risk neuroblastomas show positive results in the standard cytomorphology tests of bone marrow. Low numbers of cancer cells in bone marrow or peripheral blood (especially during or after the end of treatment) are below the standard values of detection limit in most of the classic methodologies...
|
|
|
H19 methylation determination and KCNQ1OT1 at nephroblasts , pheochromocytomas and paragangliomas using MLPA technique
Jenčová, Pavla ; Vícha, Aleš (advisor) ; Eckschlager, Tomáš (referee)
DNA methylation is an epigenetic mechanism that affects the level of gene expression. Methylation is a physiological for imprinted genes, when is required to express a gene derived only from a particular parent. If a fault occurs in the DNA methylation of these genes, various diseases may develop. The object of this work was to determine the level of methylation of H19 and KCNQ1OT1 genes, located on the short arm of chromosome 11 in 15.5 region. The aim of this study was to investigate the changes in methylation of these genes in nephroblastomas, pheochromocytomas and paragangliomas, determine what changes of target genes are present in the samples, examined and divided samples into groups according to the detected changes. File of nephroblastomas is divided into 3 groups according to the methylation changes in genes and compared with a similar study by Scott et al. 2012. File of pheochromocytomas and paragangliomas are found according to changes in the methylation of genes divided into 4 groups entirety. Found changes are aligned with the research Margetts et al. 2005. Key words DNA methylation, H19, KCNQ1OT1, nephroblastoma, pheochromocytoma, paraganglioma
|
|
|
Verification of somatic mutations important for neuroectodermal tumors (CTNNB1, BRAF, ALK)
Hrindová, Božidara ; Vícha, Aleš (advisor) ; Janatová, Markéta (referee)
The diploma thesis was focused on evidence of selected somatic mutations in genes ALK (Anaplastic lymphoma receptor tyrosine kinase), BRAF (v-Raf murine sarcoma viral oncogene homolog B1) and β-catenin (CTNNB1) through molecular - genetic methods in the target group of neuroectodermal tumors (neuroblastoma, medulloblastoma, brain tumors, paraganglioma and pheochromocytoma). Some of them are already considered as prognostic indicators which help to identify the subtype of various tumors and on the basis of this molecular - biological classification choosing the appropriate treatment. The genetic material of 133 patients was used for the analysis divided by the type of cancer. The presence of the mutation was detected in seven cases, of which two of them beloged to the gene BRAF, one to the gene ALK and four to the gene β-catenin. The subject of research in the cases of this genes were hotspot mutation sites. The purpose was to confirm the presence of the mutation in the hotspots and contribute to the studies which are aimed at the introduction of more suitable treatment through the inhibitors of mutated genes. Keywords: ALK, BRAF, β-catenin (CTNNB1), neuroectodermal tumors, sequencing, MLPA
|
|
|
H19 methylation determination and KCNQ1OT1 at nephroblasts , pheochromocytomas and paragangliomas using MLPA technique
Jenčová, Pavla ; Vícha, Aleš (advisor) ; Eckschlager, Tomáš (referee)
DNA methylation is an epigenetic mechanism that affects the level of gene expression. Methylation is a physiological for imprinted genes, when is required to express a gene derived only from a particular parent. If a fault occurs in the DNA methylation of these genes, various diseases may develop. The object of this work was to determine the level of methylation of H19 and KCNQ1OT1 genes, located on the short arm of chromosome 11 in 15.5 region. The aim of this study was to investigate the changes in methylation of these genes in nephroblastomas, pheochromocytomas and paragangliomas, determine what changes of target genes are present in the samples, examined and divided samples into groups according to the detected changes. File of nephroblastomas is divided into 3 groups according to the methylation changes in genes and compared with a similar study by Scott et al. 2012. File of pheochromocytomas and paragangliomas are found according to changes in the methylation of genes divided into 4 groups entirety. Found changes are aligned with the research Margetts et al. 2005.
|
|
|
Cytogenetic and molecular characterization of astrocytic tumors
Čurnová, Lenka ; Vícha, Aleš (advisor) ; Gemperle, Jakub (referee)
Astrocytic tumours include a heterogeneous group of tumours with different histological features. Their diagnostics and classification could be difficult in some cases. Besides histological features of the neoplastic tissue genetic mutations in the tumour cells are important for the basic characteristic of the tumours. According to the histological and clinical characters tumours of the central nervous system are divided into several malignancy grades. Low-grade astrocytomas are the most common solid tumours of children. More malignant forms (mainly glioblastomas) represent a significant group of tumours of CNS of adult patients. IDH1, TP53, EGFR, PTEN typically belong among genes which carry mutations in the cells of astrocytic tumours. Mostly pilocytic astrocytomas are often connected with mutations of the BRAF gene which is a part of the mitogen activated protein kinase (MAPK) pathway. Many modern methods are used for the investigation of the mutations in the genome of the neoplastic tissue. PCR, real-time PCR and sequencing are the most important molecular methods. The most often used cytogenetic methods which are based on the hybridization of the DNA are FISH and microarray techniques. In some cases also immunological methods could be used. The correct diagnostics of the tumour and its...
|
guest ::
RSS feed.