Ki-67, a protein used to measure tumour growth, may also help prevent chromosome errors that drive cancer, a study suggests.

The findings could change how scientists view Ki-67, a marker commonly used in breast cancer and other tumours to assess how quickly cancer cells are growing.

Researchers found the protein may help preserve genome stability by maintaining the structural integrity of centromeres, key parts of chromosomes that help ensure DNA is shared correctly during cell division.

The research was led by professor Paola Vagnarelli at Brunel University of London in collaboration with scientists at the University of Edinburgh and the Technical University of Berlin.

Professor Vagnarelli said: “Doctors already measure Ki-67 to see how aggressive a cancer might be. But our results suggest it is actually helping maintain genome stability.

“That means it may be more than a marker. It could potentially also be a therapeutic target.”

The study examined three proteins that attach to chromosomes during cell division and help rebuild the molecular system that tells each new cell what kind of cell it is.

Every human cell carries identical DNA. What makes a liver cell different from a brain cell is which genes are switched on and which are kept inactive.

When a cell divides, that entire system of switches must be rebuilt. The three proteins involved in this process were Ki-67, Repo-Man and PNUTS.

Vagnarelli’s team developed a method that individually removes each protein from a living cell at the precise point of division. Older techniques could not isolate that moment cleanly.

They found that cells rely on all three proteins to reset themselves after division, but each failed in a different way when removed.

Without PNUTS, gene activity spiralled out of control and thousands of genes switched on at once.

Without Repo-Man, cells escaped safety checkpoints that usually stop damaged or abnormal cells from continuing to divide.

“What we didn’t expect was how clean the separation was,” said Vagnarelli.

Each protein fails in its own specific way. There is no redundancy, no safety net. Which means there are three separate points at which this process can go wrong.

“When the system breaks down, cells can emerge with the wrong number of chromosomes. That condition, called aneuploidy, is seen in disorders such as Down syndrome and in many cancers.

“We also found that these chromosome errors can trigger inflammatory signals inside the cell.”

Aneuploidy means a cell has too many or too few chromosomes, which can disrupt normal growth and function.

Inflammatory signals are chemical messages that can make a cell behave as if it is responding to injury or infection.

“These cells behave almost as if they are under attack,” said Vagnarelli.

“The immune response switches on because the genome is unstable.

“That link between chromosome imbalance and inflammation could help explain patterns we see in several diseases.”

The researchers said the findings may help cancer scientists better understand how chromosome instability, loss of gene regulation and cells dividing before they are ready contribute to tumour growth.

They said understanding the normal machinery that prevents these errors may help researchers find ways to push cancer cells into making mistakes they cannot survive.

“We now have a clearer map of the machinery that resets the cell after division,” said Vagnarelli.

“That knowledge gives us a starting point for thinking about new therapeutic approaches.”

Abdominal obesity may lead to worse menopause symptoms, including forgetfulness, irritability and night sweats, a new study suggests.

The findings point to a possible link between fat stored around the waist and more severe midlife symptoms.

Researchers said waist-to-height ratio could help identify women who may benefit from more targeted support.

Dr Monica Christmas is associate medical director for The Menopause Society.

Christmas said: “Unintended weight gain during the menopause transition, especially in the midsection, is one of the most commonly reported complaints, with the most significant gains experienced in the years leading up to the final menstrual period and a couple of years after.

“This not only affects self-image but also imposes negative health risks and, as the study highlights, is associated with higher prevalence and severity of menopause symptoms.”

The study used data from more than 1,100 women who took part in the Study of Women’s Health Across the Nation.

Abdominal obesity is a build-up of fat around the waist. It often includes visceral fat, which is deep, active fat surrounding internal organs.

This type of fat releases inflammatory proteins and toxic fatty acids that can contribute to insulin resistance, cardiovascular disease, high blood pressure and a higher risk of some cancers.

Insulin resistance means the body does not respond properly to insulin, the hormone that helps control blood sugar.

The Menopause Society said abdominal obesity is estimated to affect more than 60 per cent of menopausal women.

As oestrogen levels fall during menopause, women tend to store more fat around the waist rather than the hips, even if their overall weight does not change.

The researchers noted that obesity patterns and menopause symptom burden can vary by region, but research into the effect of abdominal obesity on these symptoms remains limited.

They also said earlier studies have mainly looked at single symptoms, rather than how symptoms connect with each other.

In this study, researchers used network analysis, a method that looks at how symptoms are linked, to compare symptom patterns in women with and without abdominal obesity.

They identified abdominal obesity using waist-to-height ratios, which compare waist size with height and can be used as a simple measure of health risk linked to body fat around the middle.

The researchers concluded that women with abdominal obesity had both a higher prevalence and greater severity of a range of symptoms, as well as a distinct symptom network structure.

In particular, women with abdominal obesity reported a higher prevalence and greater severity of dizziness, hot flashes and night sweats than women without abdominal obesity.

Sleep disturbances and palpitations were also reported more often in women with abdominal obesity. Palpitations are feelings of a fast, fluttering or pounding heartbeat.

The researchers said assessment of abdominal obesity using waist-to-height ratios may help stratify women who are likely to benefit from targeted, network-based interventions rather than isolated symptom management.

Christmas said: “Educating women early about healthy lifestyle interventions to prevent midlife weight gain is key to improving mental and physical well-being during a tumultuous time frame.”