University of Freiburg researchers have found that a bacterial pathogen called Yersinia ruckeri can be manipulated at the molecular level to create a toxin that can be used to address tumor development. The pathogen is a common infectious agent of fish belonging to the Salmonidae family, where it causes enteric redmouth disease. These types of fish include salmon and trout. With the disease, hemorrhaging of the mouth, fins, and eyes occur. Redmouth disease was first reported with Idaho rainbow trout, back in the 1950s.
By studying the genome of the toxin scientists have found that the toxin injection process within the bacterial cell is similar to the types found in viruses of the sort that often attack bacteria. Further study showed the toxin, called Afp18, is a type of enzyme that can deactivate a protein called RhoA.
It is this switching mechanism that is important. The RhoA protein undertakes many important processes in the cells of fish, as well as in people. These processes include the way that cells divide and with cell cycle maintenance. The protein also has a role in the way that tumors spread. For example, RhoA has been found to be hyper-activated in gastric cancer cells.
Through undertaking work in zebra fish, the research group found that the bacterial toxin can be used to block cell division. Zebra fish are used in many experiments because the entire genome has been mapped, allowing scientists to note any changes at the genetic level as a consequence of the experiment being performed. Furthermore, the embryos of the zebra fish — which were used in the study — are relatively large, robust, and transparent.
The application of the cell blocking principle can be used to examine whether cancer tumor growth can be slowed down. The results indicate that this is theoretically possible; however, a considerable amount of research is required before a case can be made for a treatment to be developed.
The findings have been published in the journal Nature Communications. The research paper is titled “Tyrosine glycosylation of Rho by Yersinia toxin impairs blastomere cell behaviour in zebrafish embryos.”