Cancer Cells Found To Streamline Their Genome To Replicate Themselves Quicker – IFLScience

Cancer cells may be streamlining their genome in order to replicate themselves quicker. A new study has found that the cells remove large repetitive chunks of their DNA, which may explain how some drugs work in the battle against certain cancers. The study is published inPLOS Genetics.

As both human and mouse cancer cells grow, the researchers found that they startto extricate large pieces of repetitive sequences known as ribosomal DNA, the bits thathappen to code forthe ribosomes that aid in copying the genome. As this basically shortens the genome, it means that the cancer cells can simply replicate their entire genome much quicker, allowing the cancer to grow and spread at an accelerated speed.

But this removal of DNA sections comes with a cost. Studies have suggested that these portions of repetitive sequences, rather than being a mistake or meaningless, play an important role in allowing cells to survive DNA damage. By taking them out of the genome, it could go some way to explain why certaincancers are sensitive to DNA-damaging treatments.

Drugs that damage DNA are often used to treat cancer, but it's not clear why they would selectively kill cancer cells, explainsteam lead Jennifer L Gerton, an investigator at the Stowers Institute, in a statement.Our results suggest that off-loading copies of ribosomal DNA could create instability in the genome that makes cells particularly susceptible to chemotherapy with DNA-damaging drugs.

It may seem odd that the cancer cells are shedding DNA that codes for such vital components of the cell, particularly when the team expected they would increasecopies of ribosomal DNA as a way to speed up the copying of the genome. However, it turns out that the pressure exerted on the cancerous cells to proliferate is causing changes to the ribosomal DNA, making the cells get rid of the replications.

In experiments on yeast cells, getting rid of these extra copies has been found to makethe genome more sensitive to DNA damage. The team of researchers now plan tosee if this holds true with human cancer cells as well, and if so, whether it could help lead to new chemotherapy treatments in the battle against the disease.

Originally posted here:
Cancer Cells Found To Streamline Their Genome To Replicate Themselves Quicker - IFLScience