The polysaccharides in Reishi mushroom have been considered to have the ability to activate the human immune system and fight against cancer. However, the detailed functional mechinism remains a mystery to scientists. The research team of Genomic Research Center, Academia Sinica previously discovered that F3, a crude extract of fucose-containing polysaccharides from the Reishi mushroom, could stimulate the growth of many different immunocytes and boost the activity of the nature killer cells. This time, the research team further demonstrated that these polysaccharides, after injected into mice, can induce antibodies to recognize tumor-associated carbohydrate antigens on cancer cells and kill them. The results have just been published in this issue of “Proceedings of the National Academy of Sciences, USA” and already attracted great attention and highlighted by the same journal.
This work was started in Dr. Hsien-Yeh Hsu’s group of National Yang-Ming University that when they injected F3 to mice with lung cancer could slow the tumor growth, but the anticancer mechanism was not clear. After collaboration with the research team led by Dr. Wong, Chi-Huey and Dr. Wu, Chung-Yi at the Genomics Research Center, Academia Sinica, it was found that the sera from the mice immunized with F3 contain the antibodies that recognize the tumor antigens GloboH and related structures. as shown in the glycan array designed by the groups led by Wong and Wu. Moreover, the inhibition of the tumor growth is directly related to the amount of these types of antibodies. In other words, the more the Globo H recognizing anitibody, the smaller the tumor. The research team further seprated the F3 into a fucose enriched fraction called FMS for immunization and found that FMS can induce even more anti-Globo H antibodies and, thus, more effectively inhibit tumor growth. The study further demonstrated that the fucose residue is the key of Reishi mushroom’s cancer fighting ability as the anticancer activity was reduced dramatically when the fucose residue was removed. The array data further showed that FMS could induce even more specific antibodies that recognize fucose-containing tumor-associated carbohydrate antigens on the cancer cells. Moreover, Dr. Kuo-I Lin’s group at the Genomics Research Center found that it is the immunocyte B1 produced antibody IgM to recognize Globo H and related molecules to kill cancer cells in a complement dependent manner. Finally, with the assistance of Dr. Khoo, Kay-Hooi on mass spectrometry analysis, the effective structures of the fucose-containing saccharides were elucidated. This research thus established the molecular mechanism of Reishi polysaccharides with regard to their anticancer activity.
The first authors of this research paper are shared by Ph.D. student Liao, Shih-Fen of the Institute of Biochemical Sciences, National Taiwan University, and Dr. Liang, Chi-Hui of the Genomics Research Center, Academia Sinica. This research was supported by Academia Sinica and National Science Council.
Contact Person: Dr. Wu, Chung-Yi.
The related article can be retrieved in the following links: “Immunization of fucose-containing polysaccharides from Reishi mushroom induces antibodies against tumor-associatedGloboH-series epitopes,”Proc. Nat. Acad. Sci. U.S.A., 110(34):13809-14, (2013).
Related website: http://www.pnas.org/content/110/34/13809.short
