A team of Osaka University researchers has found that heterochromatin could play a valuable role in preventing large chromosomal rearrangements which can lead to cancer.
The study showed that extra-tight packaging of genomic material could prevent these large changes to the chromosomal structures.
Large changes in the structure of chromosomes, otherwise known as gross chromosomal rearrangements, can result in cell death or genetic diseases such as cancer. Chromosomal damage can also contribute to the aging process.
What is heterochromatin?
Chromatin is the mass of DNA and proteins which forms chromosomes. Heterochromatin is a more densely-coiled version of chromatin.
A region of the chromosome called the centromere is responsible for the correct segregation of chromosomes in the process of cell division. The centromeres are composed of heterochromatin.
Previously, scientists have been unable to pinpoint exact why the centromere is so tightly packed, and the role this plays in stabilising the region. The new study has helped to explain this.
Explaining its role in supressing gross chromosomal rearrangements
The team found that a feature of heterochromatin, histone H3 lysine 9 (H3K9) methylation, suppresses gross chromosomal rearrangements which are caused by repeats of the centromere.
The corresponding author Takyro Nakagawa, explained: “The results showed that repression of Tfs1/TFIIS-dependent ‘persistent’ transcription of centromere repeats is the key role of heterochromatin in the suppression of gross chromosomal rearrangements.”
The future of the research
The article, “Heterochromatin suppresses gross chromosomal rearrangements at centromeres by repressing Tfs1/TFIIS-dependent transcription,” has been published in Communications Biology.
Nakagawa commented on the potential applications of the findings, saying: “We predict that our findings will help develop methods of securing genome integrity by manipulating chromatin status rather than by changing the DNA sequence. This would be a huge accomplishment because the ability to suppress gross chromosomal rearrangements is integral to the prevention of diseases arising from chromosomal instability.”