the magazine story to find out more.
Geneticist Liping Huang's studies of zinc in
prostate cells may reveal more about the role of this nutrient in human
prostate health. Click the image for more information about it.
Does Zinc Fight Prostate Cancer?
By Marcia Wood
June 8, 2005
Scientists have known for decades that
zinc may play a role in maintaining the health of the prostate, the walnut-size
gland in males, located just behind the bladder. Now, studies led by
Agricultural Research Service (ARS)
Huang are providing new details about how zinc in the foods we eat might
keep prostate cancer cells from proliferating and spreading.
Prostate cancer is the second most common cause of cancer-related death
among American men.
Huang is based at the ARS
Human Nutrition Research Center in Davis, Calif. She's investigating the
roles of zinc-transporter proteins, which move zinc in and out of cells in
tissue, such as that in the prostate.
In a series of laboratory experiments, Huang and colleagues compared levels
of zinc and zinc-transporter proteins in certain cancerous and noncancerous
human prostate cells known as epithelial cells. They exposed the cells to a
solution of zinc, then found that the cancerous cells accumulated lower levels
of zinc compared to the normal cells. That might be explained by another of the
team's findings: The cancerous cells had lower levels of a zinc-transporter
protein known as ZIP1.
Although another zinc-ferrying-protein, ZIP3, was present in the cancer
cells, it wasn't in the correct location.
In all, the results suggest that reduced levels of one transporter protein,
ZIP1, and mislocation of another, ZIP3, may play a role in prostate cancer's
progression. These preliminary findings are the first to provide direct
evidence of the difference in levels and locations of zinc-transporter proteins
in healthy and cancerous prostate epithelial cells.
For the experiments, Huang used cells that had the same genetic background.
Dissimilar genetic backgrounds could have skewed test results.
ARS, the U.S. Department of Agriculture's
chief scientific research agency, and the National Institutes of Health of the
U.S. Department of Health and Human
Services, are funding the research.
more about it in the June 2005 issue of Agricultural Research