Chromosomes are structures that carry genes in all our cells. Every human cell has 46 chromosomes. In the nucleus of eukaryotic cells, DNA is highly folded and compacted with specific proteins into a dynamic polymer called chromatin. Gene expression, chromosome division, DNA replication, and repair all act, not on DNA alone, but on this chromatin template. The discovery that enzymes can (re)organise chromatin into accessible and inaccessible configurations revealed mechanisms that considerably e ....Chromosomes are structures that carry genes in all our cells. Every human cell has 46 chromosomes. In the nucleus of eukaryotic cells, DNA is highly folded and compacted with specific proteins into a dynamic polymer called chromatin. Gene expression, chromosome division, DNA replication, and repair all act, not on DNA alone, but on this chromatin template. The discovery that enzymes can (re)organise chromatin into accessible and inaccessible configurations revealed mechanisms that considerably extend the information potential of the genetic code. In addition, it is now established that chromatin structural features can influence gene expression. In vitro studies support a model in which chromatin functions as a barrier for the access to DNA. Therefore this organization has to be tighly regulated and dynamic to allow the protein-DNA interactions critical for nuclear functions. Importantly genome organisation provides in addition to genetic information another layer of information, so called epigenetic, which by definition means that it is stably inherited throughout cellular divisions, yet it is not encoded genetically. Thus each cell type will display a specific epigenome. We have recently constructed small human minichromosomes, which are much easier to study than the much larger normal chromosomes. The present project proposes to define the epigenetic feature across an entire human chromosome using our minichhromosomes as working models. The outcome will be a significant gain in our knowledge on the processes underlying epigenetic regulation, the organisation of specialised chromatin domain, and behaviour of the chromosomes.Read moreRead less
The Role And Inheritance Of Constitutional Epimutations In Early-onset Colorectal Cancer.
Funder
National Health and Medical Research Council
Funding Amount
$347,551.00
Summary
Traditionally familial cancers are thought to be caused by spelling mistakes within the genetic code of cancer prevention genes. Our group has found that chemical attachments to one gene (MLH1) stops it working, even where there is no spelling mistake, and that those chemical changes can be inherited in families with bowel cancer. We will determine how frequently this type of defect occurs in bowel cancer patients, how and why it arises, and if other cancer genes are similarly affected.
Epimutations As Germ-line Defects In Hereditary Cancer Syndromes
Funder
National Health and Medical Research Council
Funding Amount
$385,925.00
Summary
Traditionally familial cancers were thought to be caused and inherited by spelling mistakes within the genetic code of cancer prevention genes. Our group has found that a 'chemical coat' around the MLH1 gene, causing it to be switched off, can also be inherited in some cases of bowel cancer, without any mistakes within the gene's code. We will determine if this 'coat' causes other types of cancer and if this runs in families. We also hope to find out how the coat is formed and may be reversed.