The researchers studied the nematode worm C. elegans, which is frequently used for such genetic investigations. More than 60 percent of the genes are similar in worms and humans, including one for ENDOU, which is called ENDU-2. The current theory of tumor development suggests that cells only become cancer cells when errors, called mutations, accumulate in their genes. These arise, for example, from radiation, certain chemicals, or during aging. Qi showed back in 2017 that such errors do not have to occur in the cancer cells themselves, but they can also arise elsewhere in the body. Cancer is therefore triggered remotely, so to speak. The researcher suspected that the damaged cells in this case send signals to accomplish this, which then reprogram the other tissues. They now discovered the signal for this: ENDU-2.

„ENDOU/ENDU-2 is not only selectively discharged from stressed cells and circulated throughout the body, but it can also bind to the messenger RNA (mRNA) of many genes at the site of origin and in the target cells“, Qi explains. These mRNAs are the working copies of genes and are needed as blueprints for the production of all proteins and enzymes. What surprised the researcher was that ENDU-2 can perform two different functions under stress: at the site of origin, it cuts and destroys the mRNA, which reduces metabolism and prevents the already stressed organism from making faulty new proteins. At the destination, the RNA remains intact, and ENDU-2 helps these cells to survive. For this, however, it must be dosed precisely; otherwise it can cause tumor formation.

One conclusion that can be drawn from this could be that the worm specifically protects the embryos, i.e. its offspring, in times of great stress. “In this way, it seems guaranteed that whenever the organism’s self-healing powers are not sufficient for mother and child, it at least ensures the survival of the progeny”, speculates Prof. Dr. Ralf Baumeister, who was also involved in the study and in whose department Qi leads a research group. The Freiburg scientists now know that the loss of ENDU-2 can also reprogram stem cells. These then lose their immortality within a few generations. Next, the team wants to explore which conditions cause ENDU-2 to distinguish between destruction and protection.

The German Research Foundation is funding the Freiburg scientists’ study. In addition, they are cooperating with BIOSS – Centre for Biological Signalling Studies and the Excellence Cluster CIBSS – Centre for Integrative Biological Signalling Studies at the University of Freiburg.

Show less.