The question has shaken the scientific community for ages: why are there so few heart cancers when this disease is visibly capable of affecting any part of the body, including and especially the most fundamental to our survival? Tumors growing in the heart are found in less than 1% of autopsies and only 10% of cancers that start elsewhere spread to that organ, according to 2020 figures.
According to a study relayed by the Smithsonian Magazine, the result of work carried out on mice, this singularity is due to the mechanical force of the heartbeats, which is not anecdotal. The discovery, published April 23 in the journal Science, could help researchers develop new cancer therapies based on mechanical stimulation.
The mechanics of the heart
The team confirmed the role of heartbeat using artificial heart tissue made from rat cells. The injected cancer cells grew better in artificial tissue whose beats resembled those of a normal heart than in immobile tissue.
“Our results show that heart pulsations are not just a simple physiological function, but that they could act as a natural brake on tumor growthexplains Serena Zacchigna, clinician-researcher at the University of Trieste (Italy), who co-directed the work. This suggests that the cardiac environment is unfavorable for cancer cells not only for immunological or metabolic reasons, but also because its continuous mechanical activity physically limits their proliferation.
In addition, the scientist and her colleagues discovered that mechanical stress promoted the expression of a protein in cancer cells, called Nesprin-2, capable of modifying DNA in response to an external factor. This is an epigenetic mechanism: the inhibition of this protein in cancer cells allowed them to proliferate and spread in the heart.
The research team is currently studying the possibility of replicating the mechanical forces of the heart in other parts of the body, such as the skin and breasts, to prevent tumor growth beyond this organ, explains Serena Zacchigna, whose team is currently wondering whether high blood pressure could also help protect against cancer.
