Carnivorous fungus may help fight cancer
Arthrobotrys is a genus of fungus that carries out a fascinating lifestyle. This mold is composed of long tubes that penetrate the soil in which it grows, and obtains nutrients by secreting enzymes to digest extracellular materials. Unlike other fungi, members of this genus actually trap small roundworms called nematodes that pass through loops of hyphae. One member of the family, Arthrobotrys oligospora, has attracted attention due to small nanoparticles secreted by the fungus, which appear to play a critical role in the ability of the fungus to trap worms.
Reported in Science Daily, from an article originally published in the journal Advanced Functional Materials, researchers at the University of Tennessee found that the nanoparticles secreted by the fungus were of unusually uniform size and shape. One property of the particles is that they are easily able to pass across cellular membranes, and can potentially be used to package chemicals to deliver into target cells. The researchers found that on their own that the nanoparticles induced the production of Tumor Necrosis Factor (TNF-alpha), a signalling molecule that has important immunostimulant effects in the body. Additionally, delivery of purified nanoparticles on cancer cells inhibited their growth, and coating the nanoparticles with doxorubicin had a significant synergistic effect. Doxorubicin is a powerful chemotherapy medication that works by altering the structure of DNA and preventing DNA replication and RNA transcription.
The authors of the study highlight the novel nature of this delivery mechanism for the treatment of cancers. The difficulty which needs to be addressed with significant future research is one of specificity; how can these powerful medications be targeted specifically to the cancerous cells in the body while leaving normal cells alone? Most forms of anti-cancer therapy take advantage of the high growth rate that cancer cells show in comparison the normal cells. Consequently, the body tissues with the most significant side effects are those that reproduce rapidly: skin cells, hair cells, blood cells, and other tissues that rapidly turn over in adults. Since these nanoparticles can potentially be manipulated in the laboratory, the potential exists to coat them with chemicals that might allow them to specifically bind to cancer cells in the body, allowing them to deliver medicines directly to the cancer cells while avoiding normal cells. Consequently, identifying antigens on cancer cells that are not found on normal cells can allow scientists to create antibodies that could be attached to the nanoparticles.