Researchers led by an Indian-origin scientist have found that mushroom supplemented Soybean extract can help lengthen the life span in prostate cancer patients.
The study, led by Indian-origin researcher Paramita Ghosh and her team at University of California-Davis, was conducted in prostate cancer cells and in mice, and has found that a natural product called genistein-combined polysaccharide (GCP) could help lengthen the life expectancy of certain prostate cancer patients.
Men with prostate cancer that has spread to other parts of the body, known as metastatic cancer, and who have had their testosterone lowered with drug therapy are most likely to benefit from this study.
Lowering of testosterone, also known as androgen-deprivation therapy, has long been the standard of care for patients with metastatic prostate cancer, but life expectancies vary widely for those who undergo this treatment.
The current findings hold promise for GCP therapy as a way to extend life expectancy of patients with low response to androgen-deprivation therapy.
Paramita Ghosh, an associate professor in the UC Davis School of Medicine, led the pre-clinical study with a team that included UC Davis Comprehensive Cancer Center Director Ralph de Vere White, a UC Davis distinguished professor of urology.
The research focused on GCP, a proprietary extract cultured from soybeans and shiitake mushrooms. Researchers found that the combination of the compounds genistein and daidzein, both present in GCP, helps block a key mechanism used by prostate cancer cells to survive in the face of testosterone deprivation.
The research team had earlier shown that when a patient's androgen level goes down, cancerous prostate cells kick out a protein known as filamin A, which is otherwise attached to the androgen receptor in the cell's nucleus.
The androgen receptor regulates growth of prostate cancer cells. Once filamin A leaves the cancerous cell's nucleus, that cell no longer requires androgens to survive. Thus, loss of filamin A allows these cells to survive androgen deprivation, at and the cancer essentially becomes incurable.
The paper, titled "Enhancing the effectiveness of androgen deprivation in prostate cancer by inducing Filamin A nuclear localisation," shows for the first time that GCP keeps filamin A in the nucleus.
The team's found that metastatic prostate cancer patients with the weakest response to androgen-deprivation therapy could be given GCP concurrently with androgen deprivation therapy to retain Filamin A in the nucleus, thereby allowing cancer cells to die off.
"We want to see up to 75 per cent of metastatic prostate cancer patients lower their PSA levels, and GCP holds promise of accomplishing this goal. If that happens, it would probably be a greater therapy than any drug today," de Vere White said.