Black raspberries slow cancer by altering hundreds of genes

August 27, 2008

New research strongly suggests that a mix of preventative agents, such as those found in concentrated black raspberries, may more effectively inhibit cancer development than single agents aimed at shutting down a particular gene.

Researchers at the Ohio State University Comprehensive Cancer Center examined the effect of freeze-dried black raspberries on genes altered by a chemical carcinogen in an animal model of esophageal cancer.

The carcinogen affected the activity of some 2,200 genes in the animals' esophagus in only one week, but 460 of those genes were restored to normal activity in animals that consumed freeze-dried black raspberry powder as part of their diet during the exposure.

These findings, published in recent issue of the journal Cancer Research, also helped identify 53 genes that may play a fundamental role in early cancer development and may therefore be important targets for chemoprevention agents.

"We have clearly shown that berries, which contain a variety of anticancer compounds, have a genome-wide effect on the expression of genes involved in cancer development," says principal investigator Gary D. Stoner, a professor of pathology, human nutrition and medicine who studies dietary agents for the prevention of esophageal cancer.

"This suggests to us that a mixture of preventative agents, which berries provide, may more effectively prevent cancer than a single agent that targets only one or a few genes."

Stoner notes that black raspberries have vitamins, minerals, phenols and phytosterols, many of which individually are known to prevent cancer in animals.

"Freeze drying the berries concentrates these elements about ten times, giving us a power pack of chemoprevention agents that can influence the different signaling pathways that are deregulated in cancer," he says.

To conduct this study, Stoner and his colleagues fed rats either a normal diet or a diet containing 5 percent black-raspberry powder. During the third week, half the animals in each diet group were injected three times with a chemical carcinogen, N-nitrosomethylbenzylamine. The animals continued consuming the diets during the week of carcinogen treatment.

After the third week, the researchers examined the animals' esophageal tissue, thereby capturing gene changes that occur early during carcinogen exposure. Their analyses included measuring the activity, or expression levels, of 41,000 genes. In the carcinogen-treated animals, 2,261 of these genes showed changes in activity of 50 percent or higher.

"These changes in gene expression correlated with changes in the tissue that included greater cell proliferation, marked inflammation, and increased apoptosis," Stoner says.

In the animals fed berry powder, however, a fifth of the carcinogen affected genes – exactly 462 of them – showed near-normal levels of activity, when compared with controls. Most of these genes are associated with cell proliferation and death, cell attachment and movement, the growth of new blood vessels and other processes that contribute to cancer development. The tissue also appeared more normal and healthy.

Lastly, of the 462 genes restored to normal by the berries, 53 of them were also returned to normal by a second chemoprevention agent tested during a companion study.

"Because both berries and the second agent maintain near-normal levels of expression of these 53 genes, we believe their early deregulation may be especially important in the development of esophageal cancer," Stoner says.

"What's emerging from studies in cancer chemoprevention is that using single compounds alone is not enough," Stoner says. "And berries are not enough. We never get 100 percent tumor inhibition with berries. So we need to think about another food that we can add to them that will boost the chemopreventive activities of berries alone."

Source: Ohio State University

Explore further: Compound found in berries and red wine can rejuvenate cells, suggests new study

Related Stories

Compound found in berries and red wine can rejuvenate cells, suggests new study

November 15, 2017
By the middle of this century the over 60s will outnumber the under 18s for the first time in human history. This should be good news, but growing old today also means becoming frail, sick and dependent. A healthy old age ...

Study indicates proof of concept for using a surrogate liquid biopsy to provide genetic profile of retinoblastoma tumors

October 12, 2017
Retinoblastoma is a tumor of the retina that generally affects children under 5 years of age. If not diagnosed early, retinoblastoma may result in loss of one or both eyes and can be fatal. Unlike most cancers that are diagnosed ...

New drug, study method show breast cancer promise (Update 2)

December 13, 2013
A novel way to speed the testing of cancer drugs and quickly separate winners from duds has yielded its first big result: an experimental medicine that shows promise against a hard-to-treat form of breast cancer.

New presurgery combination therapy may improve outcomes for women with triple-negative breast cancer

December 13, 2013
The I-SPY 2 trial, an innovative, multidrug, phase II breast cancer trial, has yielded positive results with the first drug to complete testing in the trial. Adding the chemotherapy carboplatin and the molecularly targeted ...

Team links gene expression, immune system with cancer survival rates

July 20, 2015
Physicians have long sought a way to accurately predict cancer patients' survival outcomes by looking at biological details of the specific cancers they have. But despite concerted efforts, no such clinical crystal ball exists ...

A sip of resveratrol and a full p53: Ingredients for a successful cell death

November 13, 2012
Researchers at the Universidade Federal in Rio de Janeiro in Brazil have found that introduction of a normal copy of the p53 gene in p53-defective cancer cell lines makes these cells sensitive to the anti-tumor proprieties ...

Recommended for you

Encouraging oxygen's assault on iron may offer new way to kill lung cancer cells

November 22, 2017
Blocking the action of a key protein frees oxygen to damage iron-dependent proteins in lung and breast cancer cells, slowing their growth and making them easier to kill. This is the implication of a study led by researchers ...

One-size treatment for blood cancer probably doesn't fit all, researchers say

November 22, 2017
Though African-American men are three times more likely to be diagnosed with a blood cancer called multiple myeloma, most scientific research on the disease has been based on people of European descent, according to a study ...

One in four U.S. seniors with cancer has had it before

November 22, 2017
(HealthDay)—For a quarter of American seniors, a cancer diagnosis signals the return of an old foe, new research shows.

Combination immunotherapy targets cancer resistance

November 22, 2017
Cancer immunotherapy drugs have had notable but limited success because in many cases, tumors develop resistance to treatment. But researchers at Yale and Stanford have identified an experimental antibody that overcomes this ...

Researchers discover specific tumor environment that triggers cells to metastasize

November 21, 2017
A team of bioengineers and bioinformaticians at the University of California San Diego have discovered how the environment surrounding a tumor can trigger metastatic behavior in cancer cells. Specifically, when tumor cells ...

New study points the way to therapy for rare cancer that targets the young

November 21, 2017
After years of rigorous research, a team of scientists has identified the genetic engine that drives a rare form of liver cancer. The findings offer prime targets for drugs to treat the usually lethal disease, fibrolamellar ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.