The life expectancy of some prostate cancer patients could be lengthened with a natural, non-toxic substance called genistein-combined polysaccharide (GCP).
The finding came from a new study on prostate cancer cells and mice conducted by researchers from University of California, Davis, and was published in Endocrine-Related Cancer.
The men who have the highest probability to benefit from GCP are those with metastatic prostate cancer – cancer that has spread to other parts of the body – and have already used drug therapy to lower their testosterone levels.
Testosterone lowering, referred to as androgen-deprivation therapy, has been the typical way of treating patients with metastatic prostate cancer, however, life expectancies differ greatly among those who receive it.
The authors explained:
Testosterone is an androgen, the generic term for any compound that stimulates or controls development and maintenance of male characteristics by binding to androgen receptors.
The new research indicates that GCP therapy is an effective way to lengthen the life expectancy of people with low reaction to androgen-deprivation therapy.
The pre-clinical study was led by Paramita Ghosh, an associate professor in the UC Davis School of Medicine, and a team that included UC Davis Comprehensive Cancer Center Director Ralph de Vere White, a UC Davis distinguished professor of urology, Ruth Vinall in the UC Davis Department of Urology, and Clifford Tepper in the UC Davis Department of Biochemistry and Molecular Medicine directed the research in mice.
The report centered on GCP, a proprietary extract cultivated from shiitake mushrooms and soybeans, which is marketed by Amino-Up of Sapporo, Japan.
The experts discovered that the combination of two compounds found in GCP, genistein and daidzein, assist in the prevention of an important process used by prostate cancer cells to remain alive when there is a deprivation of testosterone.
The experts had previously demonstrated that when a person’s androgen level reduces, cancerous prostate cells get rid of filamin A, a protein which in other circumstances is connected to the androgen receptor in the cell’s nucleus.
The growth of prostate cancer cells is controlled by the androgen receptor. When filamin A gets kicked out of the cell’s nucleus, that cancer cell does not need androgens to stay alive anymore.
Therefore, these cells are able to survive when there is a deprivation of androgen after the loss of filamin A, and the cancer becomes terminal.
This report shows that the new therapy, GCP, detains filamin A in the nucleus.
The cancerous cells require androgens to stay alive and grow when this protein stays connected to the androgen receptor.
When starved of androgens, the cancerous cells die. Consequently, the impact of androgen deprivation extends, which in turn, lengthens the patient’s life.
“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,” according to the experts.
In order to start GCP clinical trials on people, De Vere White is now looking into funding. The authors believe that the trials will proceed quickly after they receive funding since GCP is natural and not a medication, needing fewer approvals from the government.
“We should know within the first eight months or so of human clinical trials if GCP works to reduce PSA levels,” explained de Vere White, in reference to prostate-specific antigen levels, a tumor marker to identify cancer.
de Vere White concluded:
“We want to see up to 75 percent 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.”
Written by Sarah Glynn