Curry Spice Component May Help Slow Prostate Tumor Growth
Curcumin, an active component of the Indian curry spice turmeric, may help slow down tumor growth in castration-resistant prostate cancer patients on androgen deprivation therapy (ADT), a study from researchers at Jefferson’s Kimmel Cancer Center suggests.
Reporting in a recent issue of Cancer Research, Karen Knudsen, Ph.D., a Professor of Cancer Biology, Urology and Radiation Oncology at Thomas Jefferson University, and colleagues observed in a pre-clinical study that curcumin suppresses two known nuclear receptor activators, p300 and CPB (or CREB1-binding protein), which have been shown to work against ADT.
ADT aims to inhibit the androgen receptor - an important male hormone in the development and progression of prostate cancer - in patients. But a major mechanism of therapeutic failure and progression to advanced disease is inappropriate reactivation of this receptor. Sophisticated tumor cells, with the help of p300 and CPB, sometimes bypass the therapy.
Thus, development of novel targets that act in concert with the therapy would be of benefit to patients with castration-resistant prostate cancer.
For the study, prostate cancer cells were subjected to hormone deprivation in the presence and absence of curcumin with “physiologically attainable’ doses. (Previous studies, which found similar results, included doses that were not realistic.)
A mystery has always been what factors might improve a man’s odds of having a slow-growing malignancy. A new study suggests that drinking pomegranate juice might be one of them.
Several studies have associated diets high in plant-derived polyphenols-principally, the deeply pigmented antioxidants in many fruits and vegetables-with lower risks of malignancies including prostate cancer. Because the blood-red juice of pomegranates is especially rich in such compounds, Allan J. Pantuck of the David Geffen School of Medicine at the University of California, Los Angeles and his colleagues decided to test it against metastatic prostate cancer. These are malignancies that have spread beyond the gland, which in these men had been removed or destroyed, along with tumors, by radiation.
Over time, the presence of these residual cancer cells was confirmed by rising concentrations of a protein in the men’s blood: prostate-specific antigen (PSA). Because PSA is made by prostate cells-usually cancerous ones-and because these men no longer had intact prostates, the presence of the substance indicated that cancerous prostate cells continued to exist in the men’s’ bodies, Pantuck explains.
The researchers calculated that the men’s average doubling time in PSA concentrations-a rough gauge of cancer growth-was 15 months. After men drank a glass of juice a day, their average doubling time more than tripled. In nearly one-third of men, Pantuck notes, PSA values actually fell-in a few cases, dramatically.
Although this is just one study and the juice showed no sign of curing the disease, Pantuck says it shows that pomegranate juice might be a beneficial adjunct to other therapies in men with this potentially lethal disease.
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By Janet Raloff
Curcumin augments the results of ADT, and reduced cell number compared to ADT alone, the researchers found. Moreover, the spice was found to be a potent inhibitor of both cell cycle and survival in prostate cancer cells.
To help support their findings, the researchers also investigated curcumin in mice, which were castrated to mimic ADT. They were randomized into two cohorts: curcumin and control. Tumor growth and mass were significantly reduced in the mice with curcumin, the researchers report.
These data demonstrate for the first time that curcumin not only hampers the transition of ADT-sensitive disease to castration-resistance, but is also effective in blocking the growth of established castrate-resistant prostate tumors.
U.S. researchers suggest prostate cancer patients who change to a low-fat diet with fish oil supplements may slow prostate cancer cell growth.
First author Dr. William Aronson at the University of California, Los Angeles, Jonsson Comprehensive Cancer Center said a low-fat diet with fish oil supplements eaten for four to six weeks prior to prostate removal slowed the growth of cells in human prostate cancer tissue, when compared to a traditional, high-fat Western diet.
The finding, published in Cancer Prevention Research, found the low-fat, fish oil diet reduced the number of rapidly dividing cells in the prostate cancer tissue - which is significant because the rate at which the cells are dividing can be predictive of future cancer progression. The lower the rate of proliferation, the less chance the cancer will spread outside the prostate, where it is much harder to treat.
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“This study sets the stage for further development of curcumin as a novel agent to target androgen receptor signaling,” said Dr. Knudsen. “It also has implications beyond prostate cancer since p300 and CBP are important in other malignancies, like breast cancer. In tumors where these play an important function, curcumin may prove to be a promising therapeutic agent.”
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Thomas Jefferson University (TJU), the largest freestanding academic medical center in Philadelphia, is nationally renowned for medical and health sciences education and innovative research. Founded in 1824, TJU includes Jefferson Medical College (JMC), one of the largest private medical schools in the country and ranked among the nation’s best medical schools by U.S. News & World Report, and the Jefferson Schools of Nursing, Pharmacy, Health Professions, Population Health and the College of Graduate Studies. Jefferson University Physicians is TJU’s multi-specialty physician practice consisting of the full-time faculty of JMC. Thomas Jefferson University partners with its clinical affiliate, Thomas Jefferson University Hospitals.
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Source: Thomas Jefferson University