An apple full of medicine
Most Americans don’t eat enough fruit and vegetables, despite evidence that produce contains cancer-fighting substances.
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Ramesh Gupta studies the links between cancer prevention and healthy diets.
Ramesh Gupta’s current research focus could be summed up in a few words: “Eat your fruits and vegetables.”
This may be a vast oversimplification, but it’s not too far from what he’s exploring these days.
Gupta is a lead investigator in the Cancer Prevention and Control Program at the James Graham Brown Cancer Center. His new research stems from his earliest academic endeavors. Starting with a degree in chemistry, Gupta took postdoctoral training in biochemistry at Baylor College of Medicine, Houston, leading to pioneering work on RNA (ribonucleic acid) sequencing technologies in the late 1970s. RNA is a type of a nucleic acid involved in the transcription of the body’s genetic information.
Having played a key role in finding the primary structure of transfer RNAs, Gupta decided to “take advantage of the novel technologies developed in this field and look into damaged DNA, which is a precursor for cancer.”
Gupta and his team are working on the development of DNA damage biomarkers and their applications to exposure to carcinogens, cancer risk and cancer chemoprevention. Biomarkers are byproducts left in the body after chemical exposure.
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Graduate student Harini Aiyer processes berries to be mixed into rodent diets for intervention studies.
“Over 70 percent of human cancers can be attributed to carcinogens present in the human environment,” Gupta says. “Once metabolized, these carcinogens interact with cellular macromolecules, including DNA. If the DNA lesions are not repaired before the onset of DNA replication, or are misrepaired, they can lead to mutations and ultimately the formation of cancer.”
Gupta and his associates have now made a major advancement in measuring changes in a wide spectrum of DNA lesions as cancer progresses.
He believes that the technology, termed “adducteomics,” can work in conjunction with genomics (microarray) and proteomics technologies, to provide new, sensitive tools for the molecular analysis of cancer development. New chemoprevention strategies also could result, Gupta says.
The researchers strive to “see if we can identify compounds which can inhibit DNA damage,” he explains. “In most cases there are a number of ways in which these chemoprotective agents can prevent DNA from getting damaged. We are heavily involved in developing strategies that will identify both natural and synthetic agents that can prevent DNA damage, but my primary emphasis remains on natural agents.”
Using natural compounds to prevent cancer interests Gupta. Polyphenols, for instance, are present in significant amounts in green and black tea. A similar compound, ellagic acid, is found in raspberries and strawberries.
Gupta’s laboratory is now developing new devices to administer such chemopreventive agents.
“We have been working with this compound [ellagic acid] for the last five to six years, and found it to be a significant inhibitor of DNA damage,” he says.
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Manicka V. Vadhanam, lab manager, holds a silastic (soft plastic) implant filled with a cancer-preventing substance.
At present, more than 140 million Americans don’t consume the minimum five daily servings of fruits and vegetables recommended by the National Cancer Institute.
“There is a tremendous body of data indicating that eating colored fruits and vegetables can prevent not only cancer but various other diseases as well. If we can train our children right at an early age, emphasizing that eating fruits is more than just an apple a day, that’s part of a long-term prevention strategy.”
And, Gupta adds, “The Kentucky lung cancer rate is one of the highest in the country. If we find that strawberries, raspberries or blueberries are protecting the body from cancer development, then we will try to use this diet in clinical trials. A pilot study may be set up to see if intervening with these berries or the compounds themselves can help prevent cancer development.
“Mom or Grandmother would say ‘eat your vegetables.’ We want to identify some of the protecting agents in fruits and vegetables and understand if the consumption of these items can indeed prevent cancer.”
Gupta also is looking into developing a supplement based on these natural compounds.
“The infrastructure at the Brown Cancer Center is just right” for his research, Gupta says. “I want to be a part of this effort in developing cancer prevention strategies at the center and contribute toward attaining the NCI designation.”
NCI (National Cancer Institute) designation is awarded only to the nation’s best and most comprehensive cancer centers.
(Adapted from a story in winter 2004 edition of Discoveries, the magazine of the James Graham Brown Cancer Center. Steve Hacker is a Louisville freelance writer.) Photography by Geoff Carr.
