Scientists Study Human Cancer Genes In Plants

Jun 30, 2019
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LULU GARCIA-NAVARRO, HOST:

There are human cancer genes in plants. Scientists didn't put them there. They were there to begin with. NPR's Joe Palca recently went to Oak Ridge National Laboratory in Tennessee, where he spoke with a scientist who's exploring those genes.

JOE PALCA, BYLINE: The scientist is Wellington Muchero. Oak Ridge lab is part of the Department of Energy, so Muchero and his colleagues are primarily interested in the genes that will make plants into better bio fuels. Muchero takes me into a greenhouse filled with small trees in pots.

WELLINGTON MUCHERO: So these are all poplar trichocarpa.

PALCA: Poplar trichocarpa is the black cottonwood tree. There are rows of them in this climate-controlled greenhouse.

MUCHERO: Exact same species grown under the exact same environmental conditions given the same amount of water, same amount of nutrients.

PALCA: Since they're all growing in the same environment, the only other major factor affecting the way the trees grow is their genes. When he finds a plant that grows particularly well or has some other desirable trait, he looks to see which gene is responsible. Muchero says he has no preconceived idea of what kind of genes he'll find.

MUCHERO: We have learned the hard way not to come with expectations (laughter) because we have often found we are always wrong.

PALCA: (Laughter).

For example, Muchero says some trees weren't developing the way he wanted. He found a gene that appeared to be involved and searched through the genetic database to see if there was any information about that gene; turns out there was. But surprisingly, it was a gene that had been studied for its role in human cancer - cancer of the testes.

MUCHERO: I would have never looked at a gene that's called testes specific for anything related to plants.

PALCA: But that gene was the one that allowed the trees to develop the way he wanted.

MUCHERO: So highly detrimental in humans - but the exact same behavior is what we are looking for in plants.

PALCA: Muchero says it's not just cancer genes humans and plants share. Plants and humans also share a gene for regulating glucose levels. When that gene is damaged in humans, diabetes can result. And that's bad. But back in the greenhouse, Muchero shows me plants where they deliberately damaged that gene. And they were growing faster than plants with the normal gene.

MUCHERO: So when you induce the diabetes condition in plants, not only do you get bigger plants, but you get faster growth.

PALCA: It stands to reason that plants and humans share genes. Both species are made up of cells, and all cells have to do some basic functions to stay alive. Jennifer Brophy is a bioengineer at Stanford University. She says, yes, you can find genes in plants that were first found in humans, but there are also human genes that were first found in plants. Take the genes that are responsible for setting our internal 24-hour clock, known as the circadian rhythm.

JENNIFER BROPHY: So when you wake up in the morning, having a bright room will kind of help set and keep your circadian clock running well. The molecular components of that were actually first discovered in plants.

PALCA: In fact, a lot of what we know about genetics comes from plants. Brophy says, remember. Gregor Mendel figured out the basis of genetic inheritance by studying peas.

BROPHY: But I think it's underappreciated how important plants have been for understanding human biology.

PALCA: She hopes work like Muchero's will help remind people that it's worth studying plants both for agriculture and human health.

Joe Palca, NPR News.

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