Genome aids cell research

One in three people will get cancer. Finding a cure for the disease is a long-standing goal, writes Alison Goddard.

Researchers have now moved another step closer by identifying one more factor that controls the way in which cells divide.

A team led by Sir Paul Nurse, director general of the Imperial Cancer Research Fund, has found a gene that must be "switched on" for each cell to copy the genetic information it contains. If this gene could be kept switched on, it would help prevent cancer from taking hold.

Cells each contain a set of thread-like chromosomes, which carry the genes that determine our individual character. Every time a cell divides, it must copy these chromosomes and segregate them at opposite ends of the cell. The cell then divides in two and each of these cells contains one complete set of chromosomes.

Crucially, the chromosomes are copied only once before the cell splits in two. While the cell is copying this information, it cannot divide and therefore cannot become a cancerous growth.

If researchers could define exactly what stops the cell from dividing, the work could ultimately pinpoint possible remedies.

"Understanding the processes that go on during cell division enables you to use this as potentially a much better diagnosis for cancer and to more easily identify targets to try to stop that cell from dividing," Sir Paul says.

"With these basic cell cycle controls, it is very important to stop a cell dividing until it has properly copied all its DNA and segregated it. Cancer, almost certainly, can only arise if these controls are switched off. It is very important to understand how (this happens) because that might give us a common target to look at many different cancers," he adds.

As work moves beyond the sequencing of the genome to discovering what each gene actually does, Sir Paul is enthusiastic about the prospects for cancer research.

"We can pinpoint the exact differences between a cancer cell and a normal cell, in terms of changes in genes, proteins, behaviour and the overall look of a cell. This is leading to enormous improvements in our understanding of cancer as a disease, and that is beginning to spill over into the way in which we diagnose cancer and treat it," he says.