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changes in cancer cells. In mice, one of the drugs slows multiple

myeloma, a lethal bone marrow cancer, andthe other limits fibrosarcoma, a tumor offibrous tissues. The scientists report theirfindings in two articles in an upcomingCancer Cell.

The researchers homed in on the proteincalled insulinlike growth factor-1 receptor(IGF-1R). Recent studies have linked excessIGF-1R to heightened risks of colon, prostate,breast, lung, and bladder cancers. AlthoughIGF-1R shows up on the surface of healthycells, it’s more common on tumor cells.

When bound by its natural partner,insulinlike growth factor, the receptor trig-gers far-reaching processes within a cellthat spur growth and disrupt self-destruc-tion signals. Such activation of IGF-1Rboosts healthy growth of normal cells butmay also make malignant ones proliferateunchecked.

Earlier studies also indicated that can-cerous cells respond to IGF-1R activationby spurring development of new blood ves-sels that nourish a growing tumor, saysAndrew L. Kung of the Dana-Farber Can-cer Institute and Harvard Medical Schoolin Boston. Test-tube studies showed thatinhibiting IGF-1R reverses cells’ malignantbehavior.

To test whether IGF-1R inhibitors mightstop cancer, Kung and his colleagues firstinjected mice with human multiplemyeloma cells. After 3 weeks, the research-ers began injecting some of the animals withtwice-daily doses of an IGF-1R inhibitorcalled NVP-ADW742, while other mice gotinert shots. After 19 days of this treatment,mice getting the inhibitor had smallertumors; they also outlived their coun-terparts.

In the other study, researchers in Switzerland implanted fibrosar-coma tumors under the skin ofmice. One week afterimplantation, one groupof mice received twice-daily oral doses of an IGF-1R inhibitor calledNVP-AEW541, whileanother group got aninert substance. Elevendays after the start of treat-ment, mice getting the drughad tumors about one-third the size of thosein the mice receiving the placebo, saysFrancesco Hofmann, a biochemist atNovartis Pharma AG in Basel, Switzerland.The company developed the two IGF-1Rinhibitors, and Hofmann was a coauthorof both reports.

The inhibitors disable a portion of IGF-1R that acts as an enzyme within cells,says Derek Le Roith, chief of the DiabetesBranch at the National Institutes of Healthin Bethesda, Md. Researchers who took asimilar approach to disrupting enzyme sig-

nals in tumor cells, he says, developed theanti-leukemia drug imatinib mesylate, alsocalled Gleevec.

IGF-1R inhibitors don’t appear to erad-icate cancer. But Kung and his colleagueshave shown in lab-dish experiments thatIGF-1R suppression works even againstcancer cells that are resistant to conven-tional chemotherapy. —N. SEPPA

Special TreatmentFuel cell draws energy from waste

A team of environmental engineers atPennsylvania State University has createda fuel cell that breaks down organic matterin wastewater and, in the process, generatessmall amounts of electricity.

The researchers say this dual activitycould significantly reduce the costs associ-ated with current water treatment in indus-trialized countries and make such treat-ment more widely available in developingcountries.

The prototype fuel cell consists of a cylin-drical Plexiglas chamber, 15 centimeterslong and 6.5 cm wide, in which theresearchers arranged eight graphite rodsaround a hollow carbon-and-platinumtube. The rods serve as negative electrodes,or anodes, and the tube serves as a positiveelectrode, or cathode.

When the researchers pump a sample of wastewater from the local treatmentplant into the fuel cell, bacteria in the water

stick to the graphite rods. There, the microbes

break down the sam-ple’s organic matter

in a process thatextracts electrons

from the waste andtransfers them to the

rods. From there, the elec-trons flow through a wire to the

cathode, generat-ing electricity.

The breakdownof the organic mat-ter also generatesprotons, whichmigrate throughthe wastewatertoward the cath-ode. There, theprotons combinewith electrons and

oxygen to form pure water.Researchers have already fabricated

microbial fuel cells that run on glucose(SN: 10/25/03, p. 270). However, says leadinvestigator Bruce Logan of Penn State in

University Park, “I don’t think anybodybelieved that you could do this with domes-tic wastewater.”

“It’s a completely new concept for treat-ing wastewater,” concurs Bruce Rittmann,an environmental engineer at Northwest-ern University in Evanston, Ill.

Current treatment facilities use bacteria-laden tanks to clean wastewater. To do theirjob, the bacteria require oxygen, whichaccepts electrons from the waste. Half ofthe $25 billion spent annually on waste-water treatment in the United States goesto aerating tanks, according to the Associ-ation of Metropolitan Sewerage Agencies.

The fuel cell–based wastewater-treat-ment system could eliminate this costlyrequirement, Logan says. What’s more, theelectricity the fuel cell generates could beused to pump water through the system.

So far, the fuel cell can produce up to150 milliwatts of electricity per squaremeter of electrode surface. With improve-ments to the system, “I think we canprobably reach something on the order of500 to 1,000 milliwatts per square meter,”says Logan. This would be enough powerto pump an entire community’s waste.

He and his colleagues describe their newfuel cell in an upcoming issue of Environ-mental Science & Technology.

Currently, the bacteria in the Penn Statefuel cell can eliminate close to 80 percentof the organic matter in wastewater, a per-formance approaching that of existing treat-ment methods. By covering the electrodeswith specific strains of bacteria that areespecially adept at breaking down waste,the researchers could make such deviceseven more efficient, Rittmann says.

The fuel cell also needs to become lessexpensive, says Logan. He and his col-leagues are exploring different materialsthat would reduce the costs of its compo-nents. —A. GOHO

Meat of the MatterFish, flesh feed gout, but milk counters it

Alexander the Great had it. BenjaminFranklin and Charles Darwin also sufferedfrom what was once known as the “patricianmalady.” Their common affliction was gout,an arthritic condition that causes spells ofintense pain, most often in the big toe.

Nutrition research now consolidates anancient notion that a rich-man’s diet, heavyin meat and seafood, contributes to the dis-ease. Not all animal products are bad, how-ever. Low-fat dairy foods offer protection, atleast for men who haven’t yet developed gout.

The disease’s link to overconsumption of

POWER SLUDGEAs wastewater flowsthrough this new typeof fuel cell, microbesbreak down the organicmatter and releaseelectrons, which flowfrom negativeelectrodes to a centralpositive electrode.

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meat, as well as alcohol, has been assumedfor centuries. Once found mainly in wealthymen, gout has spread along with the avail-ability of meat. Today, gout affects about 5 million U.S. residents, mostly men andpostmenopausal women.

Scientists have long known that goutdevelops when joints become fouled withcrystals of uric acid, which is a natural diges-tion product of purine. Because meat,seafood, and many legumes are rich inpurine, doctors have advised that eating toomuch of these foods might overwhelm thebody’s capacity to eliminate uric acidthrough the kidneys.

Taking anti-inflammatory drugs anddrinking plenty of water can shorten anattack of gout from several days to less than24 hours. Alcohol consumption and kid-ney problems worsen gout by slowing downthe body’s elimination of uric acid.

To pin down the link between gout anddietary purine, Hyon K. Choi and his col-leagues at Harvard Medical School inBoston followed 47,150 men who had vol-unteered for a broad study of diet and health.Every fourth year, each man completed aquestionnaire about his eating habits. Noneof the men had gout initially, but 730 of themdeveloped it during the 12-year study.

Men who consumed the most meat,including chicken and organ meat, were 41 percent more likely to develop gout thanmen who ate the least meat were, Choi andhis colleagues report in the March 11 NewEngland Journal of Medicine. The resultfor seafood was similar.

The team estimates that each daily serv-ing of meat increased gout risk by 21 per-cent, while each daily serving of fish or shell-fish increased it by 7 percent.

The men who consumed low-fat dairyproducts most frequently had just half therisk of gout as men who ate the fewest suchproducts did. Each daily serving of skimmilk or low-fat yogurt reduced gout risk byabout 21 percent, the data suggest.

Neither high-fat dairy products norpurine-rich vegetables appear to influencegout risk, the researchers found.

Each daily serving of beer elevates goutrisk by 49 percent, but other alcoholic bev-erages have less effect, Choi reported at ascientific meeting last October.

The study provides “scientific validation”of the suspected relationships between goutand meat, says Richard J. Johnson of theUniversity of Florida in Gainesville. Meat-rich modern diets are already implicatedin rising global epidemics of diabetes, obe-

sity, and heart disease, he adds, and “itappears that gout should be considered partof that spectrum.” —B. HARDER

New GreenEyesFirst butterfly that’sgenetically modified

Scientists have for the first time geneticallyengineered a butterfly, inserting a jellyfishgene into an African butterfly so that itseyes fluoresce green.

The butterfly, Bicyclus anynana, servesas an important subject for studies of howgenes control development and how thosecontrols evolve, says Antónia Monteiro ofState University of New York (SUNY) at Buf-falo. She and her colleagues figured out howto use molecular techniques to transform thebutterfly and open new research opportuni-ties in genetics, she says. The researchersdescribe their work in an upcoming issue ofthe Royal Society of London’s Biology Letters.

“I think the transformation is a veryimportant tool,” comments Daniel Bopp ofthe Zoological Institute of the University ofZurich, whose team in 2001 made the firstgenetically modified housefly. “It’s a verytargeted way to try to understand the func-tion of a gene,” he says.

It’s been more than 20 years sinceresearchers first genetically engineered aninsect, the laboratory fruit fly. In the pastdecade, the pace has picked up, and biologists

have worked out how to manipulate a widevariety of other insects, including severalmosquitoes, screwworms, and two moths—the silkworm and the pink bollworm.

To get genes into a new organism,researchers depend on bits of DNA calledtransposons, which naturally infiltrate ahost’s genes. Monteiro, working with Jef-frey M. Marcus of Western Kentucky Uni-versity in Bowling Green and DianeRamos of SUNY Buffalo, ferried the jelly-fish gene in modified forms of the trans-posons Hermes, which was originally froma housefly, and piggyBac, from a cabbagelooper moth.

The researchers chose the jellyfish genefor a green fluorescent protein that otherresearchers had used to create glowing greeneyes in houseflies and some other insects.

The team injected the gene and a mod-ified transposon into each of more than10,000 butterfly eggs. About 95 percent ofthe eggs died. Of the survivors, 5 percentgetting piggyBac and 10 percent gettingHermes transposons passed along green-fluorescing eyes to their offspring.

Monteiro plans to use this technique tostudy genes suspected of creating spots onbutterfly wings (SN: 2/15/03, p. 104). Pre-vious research has shown that similargenes in fruit flies control top-bottom ori-entation, leg development, and otherdevelopmental milestones. Monteiro will,for example, add extra copies of one ofthese genes and turn it on in unusualplaces. Ultimately, she says she wants toknow, “How is it that the same old genesacquire these totally novel functions inbutterfly wings?” —S. MILIUS

SCIENCENEWSThis Week

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EYE FOR EYES The natural form of an African tropical butterfly Bicyclus anynana.Inset: The magnified eye of a genetically engineered butterfly glows green.

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