A promising new study pinpoints a fish toxin that could be used to develop new cancer treatments.
The Yersinia species of pathogens can cause serious illnesses such as the bubonic plague and nasty gastrointestinal infections, the Bioss Center for Biological Signaling Studies reported. These microbes have also been linked to the redmouth disease in Salmonidae (a group that includes salmon and trout), which can impose a significant loss on fishing industries.
In their study, the researchers identified a toxin injection machine in the Y. ruckeri genome that resembled viruses known to attack bacteria. They demonstrated that the toxin Afp18 is an enzyme that deactivates the switch protein RhoA, which is responsible for vital cell processes in both humans and fish. One of these processes is the buildup and breakdown of actin filaments that are necessary for both cell division and tumor metastases.
To make their findings, the researchers injected the toxin Afp18 into zebra fish embryos, causing cell division to be halted and preventing the embryos from developing; the actin filaments in the fish cells were also observed to collapse. This occurred because the Afp18 attaches the sugar molecule N-acetylglucosamine onto the amino acid tyrosine in RhoA. The researchers observed this process through an X-ray analysis of Afp18-modified RhoA crystals.
"Rho-regulatory proteins are involved in the growth of cancer, especially metastasis. For this reason, the researchers from the University of Freiburg believe that this fish toxin has great therapeutic potential in cancer treatment," the researchers concluded.
The findings were published in a recent edition of the journal Nature Communications.
