The scientists from the Dundee University solved a mystery concerning one of the most fundamental processes in cell biology, being part of a new discovery meant to tackle cancer one day.
It is known that the process by which cells copy their own chromosomes, and make new cells is vital to all of life. These contain the genetic blueprint that makes us unique, as the information must be copied perfectly, for new cells to survive and carry out their function. In the case where the process of copying goes wrong, abnormal cells are created, increasing the risk of cancer development.
The proteins found in the cell combine in order to build a molecular machine called the replisome, which is known to play a vital role in copying the double helix of DNA that is at the heart of each chromosome. The replisome is built once during the life of each cell, and then disassembled to ensure that cells just make a single copy of each chromosome.
The researchers were able to find that the human cells are easier to work with, compared to those pertaining to animals, which have at least two disassembly mechanisms. The gene needed for one of these processes is lost in a number of human cancers, suggesting a new approach by which these tumors could be treated.
By looking at the yeast, it was found that not only is it very similar genetically to humans, but also that one of the many components of the replisome undergoes a change called “ubiquitylation” after the chromosomes have been copied, marking the replisome for disassembly by the cell’s recycling machinery. On this occasion, the genetic studies show that if the replisome is not taken apart but instead, it remains glued to the chromosomes, may lead to a series of major problems.
The work represents another significant step towards understanding the processes at the heart of the human cells, which is vital for developing new treatments to tackle diseases. In almost all stages of cancer development, errors in the chromosome copying machinery can be observed.
The real challenge remains the struggle to copy chromosomes in such a way that it does not affect other parts of the body, killing the malignant cells without placing the patient at risk. The goal is represented by the effort of producing new forms of chemotherapy that will kill cancer cells, without hurting the healthy ones.