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The study of genetic changes of children patients suffering from the acute lymphoblastic leukemia (ALL) using mFISH / mBAND and micro-arrays.
Bártů, Linda ; Zemanová, Zuzana (advisor) ; Březinová, Jana (referee)
Acute lymphoblastic leukemia is the most common malignancy in children. The most important examination at the time of diagnosis includes karyotype of leukemic cells which divides patients into prognostic groups according to cytogenetic finding. In up to 90 % of patients the chromosomal aberrations with well known clinical significance are designated. One of cytogenetic type is high hyperdiploid ALL (51-68 chromosomes) associated with favorable prognosis. Nevertheless, relapses of the disease occur even in these children. One possible reason why this happens could be an increased genomic instability of leukemic cells that causes cryptic structural rearrangements. In a retrospective study, we examined a total of 232 children with newly diagnosed B-ALL using conventional cytogenetic analyses and interphase fluorescence in situ hybridization (I-FISH) with a panel of DNA probes (Abbott Vysis) in order to detect heteroploid cells. In patients with suspect cryptic structural chromosome aberrations, we analyzed the karyotypes in detail by multicolor FISH and multicolor banding (mFISH/mBAND; MetaSystems). The extent of aberrations was determined by comparative genomic hybridization on BAC arrays (array CGH; BlueGnome). Cell clones with high hyperdiploid karyotype were detected in a total of 102 children (44 %). In...
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Cytogenetic methods in genotoxicology
Bártů, Linda ; Daňková, Pavlína (advisor) ; Langová, Martina (referee)
We are constantly exposed to a variety of factors which may be a cause of DNA mutations. The influence of mutagens of physical, chemical and biological origin is studied by genotoxicology. Ionic radiation is among the most common physical mutagens, benzene, vinylchloride or some drugs represent the chemical mutagens, while some viruses and may act as biological mutagens. The repair mechanisms of double strand breaks can be divided into those that require HRR-homologous sequences and those that may use of microhomologies consisting of a short DNA sequence (NHEJ). Both mechanisms can lead to aberrations of chromosomes, if they are not precise. Acquired chromosomal aberrations include translocation, common in cancer cells; deletion; or the production of acentric fragments, dicentrics and rings. Chromatid aberrations includes chromatid breaks and chromatide exchanges. There are various methods for detecting/examining such mutations and these can be categorised according to the phases of the cell cycle. The basic method is clasic Giemsa stain which reveals the most of aberrations except translocations and inversions and numeric abnormalities in metaphasic cells. Another way of testing mutagenicity is determining the rate of sister chromatide exchange; or the so called micronucleus test used to measure...
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The study of genetic changes of children patients suffering from the acute lymphoblastic leukemia (ALL) using mFISH / mBAND and micro-arrays.
Bártů, Linda ; Zemanová, Zuzana (advisor) ; Březinová, Jana (referee)
Acute lymphoblastic leukemia is the most common malignancy in children. The most important examination at the time of diagnosis includes karyotype of leukemic cells which divides patients into prognostic groups according to cytogenetic finding. In up to 90 % of patients the chromosomal aberrations with well known clinical significance are designated. One of cytogenetic type is high hyperdiploid ALL (51-68 chromosomes) associated with favorable prognosis. Nevertheless, relapses of the disease occur even in these children. One possible reason why this happens could be an increased genomic instability of leukemic cells that causes cryptic structural rearrangements. In a retrospective study, we examined a total of 232 children with newly diagnosed B-ALL using conventional cytogenetic analyses and interphase fluorescence in situ hybridization (I-FISH) with a panel of DNA probes (Abbott Vysis) in order to detect heteroploid cells. In patients with suspect cryptic structural chromosome aberrations, we analyzed the karyotypes in detail by multicolor FISH and multicolor banding (mFISH/mBAND; MetaSystems). The extent of aberrations was determined by comparative genomic hybridization on BAC arrays (array CGH; BlueGnome). Cell clones with high hyperdiploid karyotype were detected in a total of 102 children (44 %). In...
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Cytogenetic methods in genotoxicology
Bártů, Linda ; Langová, Martina (referee) ; Daňková, Pavlína (advisor)
We are constantly exposed to a variety of factors which may be a cause of DNA mutations. The influence of mutagens of physical, chemical and biological origin is studied by genotoxicology. Ionic radiation is among the most common physical mutagens, benzene, vinylchloride or some drugs represent the chemical mutagens, while some viruses and may act as biological mutagens. The repair mechanisms of double strand breaks can be divided into those that require HRR-homologous sequences and those that may use of microhomologies consisting of a short DNA sequence (NHEJ). Both mechanisms can lead to aberrations of chromosomes, if they are not precise. Acquired chromosomal aberrations include translocation, common in cancer cells; deletion; or the production of acentric fragments, dicentrics and rings. Chromatid aberrations includes chromatid breaks and chromatide exchanges. There are various methods for detecting/examining such mutations and these can be categorised according to the phases of the cell cycle. The basic method is clasic Giemsa stain which reveals the most of aberrations except translocations and inversions and numeric abnormalities in metaphasic cells. Another way of testing mutagenicity is determining the rate of sister chromatide exchange; or the so called micronucleus test used to measure...
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