In what has been called a major step toward the end of the cancer fight, researchers have seen how cancer cells spread from the initial tumor to our bloodstream. The findings suggest that secondary growths called metastases are the cause. They "punch" their way through the weak walls of small blood vessels. They do it by targeting a molecule that is called Death Receptor 6. After this, there is a self-destruction process of the blood vessels, which allows the cancer to spread.
According to the team that hails from Goethe University Frankfurt and the Max Planck Institute in Germany, disabling Death Receptor 6 could block the spread of cancerous cells. That is, if they don't have alternative ways to access the bloodstream.
"This mechanism could be a promising starting point for treatments to prevent the formation of metastases," said lead researcher Stefan Offermanns.
This is incredibly important to the fight against cancer because most deaths are not caused by that original tumor, but rather by the spread.
Once they break through the blood vessels, these cells target the body's endothelial cells. These cells line the interior surface of blood and lymphatic vessels in a process called necroptosis or "programmed cell death."
According to the researchers, this is all triggered by the DR6 receptor molecule. Once that molecule is targeted, cancer cells can travel throughout the weakened cells by a gap in the vascular wall. The team used lab-grown cells and mice. In those mice, when DR6 was disabled, less necroptosis and less metastasis were recorded.
The scientists have reported their findings in Nature.
The next step will be to look for potential side effects that could be caused by the disabling of DR6. We then have to find whether or not the results are true for humans. If so, it could have serious implications for humans.
Still, there are other thoughts about how cancer spreads throughout the body. Scientists at the University of California, Los Angeles found that tumor cells can also spread throughout the body via the bloodstream using a mechanism called angiotropism, which causes some cancers to cling to the outside of the blood vessels.
"If tumour cells can spread by continuous migration along the surfaces of blood vessels and other anatomical structures such as nerves, they now have an escape route outside the bloodstream," explained researcher Laurent Bentolila from UCLA.