In a recent effort to identify more novel treatments for cancer, Chinese researchers Wansong Chen and You-Nian Liu of the Central South University were able to demonstrate how nanoenzymes could be used to help fight back against tumors. Nanoenzymes are essentially nanoparticles which are designed to mimic biological enzyme activity. An enzyme catalyzes, or speeds up, the reaction rates of particular molecules through its active site, which comprises of a very small part of the overall enzyme. Nanoenzymes work similarly by mimicking the receptors involved in catalysis at an enzyme’s active site, but are more useful in that they’re much smaller and can be easily synthesized (Sharma).
For their research, Chen and Liu utilized copper telluride, a nanoenzyme which could mimic oxidase and peroxidase activity, allowing it to alter the oxidation state of its target (Chen). Copper telluride is particularly promising because its target substrate, the antioxidant glutathione, is found at much higher levels in tumor cells. As an antioxidant, glutathione would normally fight back against reactive oxygen species, which are often thought to cause cancer. In cancer, however, high levels of reduced forms of glutathione work to protect tumor cells from further oxidative stress, preventing tumor cell death (Traverso). By introducing the nanoenzyme to tumor cells, and subsequently irradiating them, the researchers could selectively target tumor cells because of their higher glutathione levels. The nanoenzymes could then convert the reduced glutathione to oxidized glutathione, preventing the tumor’s protection from oxidative stress.
Their results are significant for a couple of reasons. Not only does the oxidative stress cause eventual cell death in both tumor cultures and mice model tumors, but it also allows for the body to mount an immune response to the tumor.. This is significant because cancer cells typically go undetected by the immune system and are constantly working to suppress any sort of immune response. The researchers found that the stress tumor cells are subject to as a result of copper telluride activity allows for inflammatory signals to be released, leading to an increase in T-cell activity (Chen). This increase in T-cells further suggests some amount of acquired immunity is gained as a result of the nanoenzyme treatment, thus allowing the body to mount future responses to the cancer if it were to appear again.
Although further testing needs to be done, nanoenzymes present a very promising route to treating cancer. The results of copper telluride treatment have shown that nanoenzymes can aid in killing tumor cells and activate an immune response to the tumor. Such treatment could be a huge step forward in targeted cancer therapy, and could potentially have long-term benefits based on its effect on immunity towards cancer. In the future, nanoenzymes could very well become an essential tool in developing personalized cancer therapies for patients.