Scientists continue to search for increasingly powerful drugs to take on cancer cells and inhibit tumor growth, and nature continues to provide them with a rich source of inspiration. The latest example comes from white button mushrooms, which a team of researchers has found can suppress prostate tumor growth in mouse models and induce other signs of anti-cancer activity.
The research was led by Shiuan Chen, from cancer research center City of Hope, whose previous investigations around white button mushrooms and cancer had returned some intriguing results. As part of a phase one clinical trial, white button mushroom powder was given to patients with recurrent prostate cancer, which appeared to reduce levels of what's known as prostate-specific antigen (PSA) in their blood.
While heightened PSA levels can serve as a biomarker of prostate cancer, they can also be the result of infections or entirely benign tumors that will never require treatment. As a result, high PSA readings can quite often lead to unnecessary biopsies and angst for patients, with up to 75 percent of men who return these readings then returning negative cancer results from their biopsies.
In any case, for Chen and his team, the effects of the white button mushroom powder on PSA levels was significant enough to warrant further investigation. So they drew up new experiments to investigate the mechanisms behind the relationship, beginning with prostate cancer cells that were subjected to a white button mushroom extract in the lab. In doing so, the team found the extract suppressed the activity of androgen receptors, which the cancer cells depend on to grow.
“Androgens, a type of male sex hormone, promote the growth of prostate cancer cells by binding to and activating the androgen receptor, a protein that is expressed in prostate cells,” says co-author Xiaoqiang Wang. “White button mushrooms appear to suppress the activity of the androgen receptor.”
In further experiments, the team treated mice implanted with human prostate tumors with white button mushroom extract. Following six days of treatment, the extract was found to produce a significant suppression of tumor growth, along with a decrease in PSA levels.
“We found that white button mushrooms contain chemicals that can block the activity of the androgen receptor in mouse models, indicating this fungus can reduce PSA levels,” Wang says. “While more research is needed, it’s possible that white button mushrooms could one day contribute to the prevention and treatment of prostate cancer.”
The research was published in the Journal of Nutritional Biochemistry.
Source: Endocrine Society
