| Summary: | DNA methylation is an epigenetic alteration which occurs during the development
and lifetime of mammalians. It has an essential gene transcription regulation function
and has been shown to be a common alteration at the root of several malignancies.
Regions with high concentrations of CpG sites are classified as CpG islands which
usually lie in the promoter regions. Hypermethylation of these promoter regions
represses transcription of tumour repressor genes, which causes gene silencing.
Specific methylation profiles can be compiled for different types of cancers. These
profiles are of great importance due to their diagnostic, risk assessment and
therapeutic potential, in addition to increasing the knowledge and understanding of
the pathogenesis of tumorigenesis and oncogenesis.
The aim of this study was to establish and optimize a method to measure the DNA
methylation status of specific human genes, i.e. cancer related genes. Methylationspecific
PCR (MSP) was used to analyze the methylation status of the p76 and
RASSFIA promoter CpG islands following the sodium bisulfite conversion of
unmethylated cytosines to uracils since this is a sensitive, efficient and relatively fast
method with high-throughput potential.
The MSP assay was established and applied successfully to DNA isolated from
whole blood, plasma (free-circulating DNA) and paraffin-embedded tumour tissue.
The results obtained showed that for the p76 promoter sequence, the methylation
status in all control individual DNA samples was unmethylated. The patient DNA
samples had diverse p16 promoter methylation levels. The tumour DNA sample
displayed both methylated- and unmethylated-specific products. This was also
observed for this patient's free-circulating DNA sample, but not for the whole blood
DNA sample. === Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2007
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