Mutant Cells The Keep Trying To Replicate Their DNA Increase Cancer Risk

According to new research from USC certain mutated cells were found to continuously trying to replicate even after medicine robbed them of all raw material to do so. For the first time scientists were able to see that even when chemotherapy drugs shut down the DNA replication process of most cancer cells, "checkpoint mutants" kept unwinding the DNA and creating more damaged DNA strands. These damaged strands could then result in abnormalities seen in cancer cells. Up until now it was believed that these checkpoint mutants stopped replicating because of DNA damage and instead just fell apart. But this new discovery suggests that instead the replication process continues and adds to the damage.

A team from USC used a common chemotherapy drug in order to put stress on fission yeast cells while undergoing the DNA replication process. This drug deprives the cells of nucleotides which are necessary to build the DNA strands. It was believed that with the loss of nucleotides the cell would stop trying to replicate their DNA but instead it was found that the checkpoint mutants ignore this signal. They keep trying to replicate their DNA by unwinding the strands until they break, which is the worst possible damage that can be done to a cell. Because of this extreme damage it is thought that an increased cancer risk comes from this. What they are still trying to determine is what happens to the mutant cells that survive this process.

This research could lead to how checkpoint-defensive human cancer cells preserve their DNA and somehow resist chemotherapy. With cancer being such a traumatic and overwhelming disease, any information and improvement in this could make incredible differences.