News / Health

Researchers Use Bacteria to Kill Tumors

Jessica Berman

Researchers are developing a promising therapy to treat cancerous tumors - by injecting them with a bacterium found in soil.  So far, the experimental treatment has mostly been tested in pet dogs, but investigators hope they have found an effective anti-cancer therapy for people.

Using bacteria to treat cancer is not a new concept. It was first tried about a century ago. But despite promising results, the microbial therapy fell out of favor with the advent of powerful chemotherapy drugs and radiation.

Now, researchers are bringing back the use of bacteria to treat solid tumors. In a study published in the journal Science Translational Medicine, scientists report how the modified spores of a soil bacterium - called C. novyi - were directly injected into naturally-occurring tumors in a group of 16 dogs ... and shrank or completely eliminated them.

In three of the dogs, the tumors were completely eradicated within 21 days of having the spores injected.  There was at least a 30 percent reduction in the size of the cancerous tumors in three other dogs in the group.

Meanwhile, in one human patient with an advanced soft tissue tumor that had spread to her abdomen, the spore treatment significantly reduced the tumor in and around the bone in the woman’s arm where the cancer originated.  

Scientists modified the C. novyi bacterium, because at full strength, an infection could be fatal.

Shibin Zhou is head of experimental therapeutics at John Hopkins University School of Medicine in Baltimore, Maryland.

He says the C. novyi spores thrive in oxygen-poor environments, such as the middle of a bulky tumor. Once injected, the spores begin to destroy the tumor cells that traditional cancer treatments can not reach.

“When the bacteria grow, they will deprive the tumor cells of their normal nutrients.  And also we have found that these bacteria do secrete enzymes that can degrade proteins and other things that tumors may rely on," said Zhou.

More important, Zhou says, is that the microbe can also prompt a strong immune response against the tumor.

“And the immune response will attack not only the bacteria themselves, but also the tumor cells," he said.

In experiments with mice, the bacterial therapy appeared to stimulate a lingering immune response against  cancer cells that had spread.  Such a response has not yet been seen in the dog or human studies.
 
Rats with brain tumors that had the microbial therapy survived 33 days after treatment compared to 18 days for rats that did not receive C. novyi spores.

Zhou says researchers are now trying to engineer the bacterium so it causes milder side effects from infection, as well as looking for other microbes that might work against cancer.

It’s possible,he  says, that the bacterial therapy can be combined with chemotherapy and radiation for a more powerful anti-cancer effect.  

 

You May Like

Video VOA Exclusive: Poroshenko Wants Russia's UN Veto Stripped

Ukrainian president tells VOA's Myroslava Gongadze that global community would be safer if Russia's ability to play spoiler were ended More

Crime and Espionage Becoming Tangled Online

As the lines between cyber-crime and espionage blur, fighting hackers becomes harder More

Crowdfunding Helps Save Neil Armstrong's Spacesuit

Smithsonian turns to Kickstarter to raise more than $700,000 to help preserve the spacesuit worn by the first man to walk on the moon More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Drowned Migrant Toddler Photo Triggers European Outragei
X
Henry Ridgwell
September 04, 2015 11:36 AM
The harrowing picture of a drowned three-year-old Syrian boy washed up on a Turkish beach appears to have galvanized Europe’s leaders into doing more to address the refugee crisis. France, Germany and Italy issued a joint call Thursday for compulsory quotas of refugees for all EU states. But there were chaotic scenes in Hungary as police tried to force migrants off a train heading for Austria. Henry Ridgwell has more. And a caution, some of the images in this report may be disturbing.
Video

Video Drowned Migrant Toddler Photo Triggers European Outrage

The harrowing picture of a drowned three-year-old Syrian boy washed up on a Turkish beach appears to have galvanized Europe’s leaders into doing more to address the refugee crisis. France, Germany and Italy issued a joint call Thursday for compulsory quotas of refugees for all EU states. But there were chaotic scenes in Hungary as police tried to force migrants off a train heading for Austria. Henry Ridgwell has more. And a caution, some of the images in this report may be disturbing.
Video

Video Russians Observe 11th Anniversary of Beslan School Attack

This week, Russians have been observing the 11th anniversary of the attack by Islamic militants on a school in Russia's North Caucasus region that killed more than 330 hostages, including 186 children. The three-day siege and massacre that started on September 1, 2004 took place in Beslan, a town in the republic of North Ossetia, and is one of the bloodiest terrorist acts ever in Russia. VOA's Mike Richman reports.
Video

Video Native Americans Debate: Father Serra, Saint or Sinner?

Pope Francis will canonize an 18th century missionary to Spanish California during a papal visit to the United States this month.  But some Native Americans have criticized the elevation to sainthood of the missionary priest, Junipero Serra. VOA's Mike O’Sullivan has more from Los Angeles.
Video

Video Calais School Offers Another Face of Europe’s Migrant Crisis

Europe is facing mounting criticism over how it’s handling its biggest migration crisis since World War II. But not all Europeans believe building walls or passing repressive policies are the answer. A school for migrants in the French port city of Calais, is opening doors and building bonds across nationalities. VOA's Lisa Bryant reports.
Video

Video Kurdish Fighters on IS Frontline Ready for Offensive

Finger on the trigger, the Kurdish Peshmerga soldier stared across the dust at a village taken over by Islamic State extremists. The Kurdistan’s Khazir frontline, just 45 minutes from the Islamic State stronghold of Mosul. And at this point, the militants were less than two kilometers away. VOA's Sharon Behn reports.
Video

Video China Announces Troop Cuts at WWII Parade

Chinese President Xi Jinping Thursday announced plans to cut the world’s largest military force by 300,000 troops. The announcement was made during a massive military parade to commemorate victory over Japan in World War II. The event was shunned by most Western leaders and for some is raising fresh concerns about China’s military ambitions. VOA’s Bill Ide has more from Beijing.
Video

Video Russia-Japan Relations Cool as Putin Visits China for WWII Anniversary

Russian President Vladimir Putin is in Beijing for commemorations of the 70th anniversary of China's WWII victory over Japan. Putin is expected to visit Japan later this year, but tensions between Tokyo and Moscow over islands disputed since the war, and sanctions over Ukraine, could pour cold water on the plan. VOA's Daniel Schearf reports.
Video

Video Yemen ‘on Brink of Disaster’ as Medical Shortages Soar

Aid agencies warn Yemen is on the brink of humanitarian disaster – with up to half a million children facing severe malnutrition, and hospitals running out of basic medicines. There are fears Yemen's civil war could escalate as the coalition led by Saudi Arabia tries to drive back Houthi rebels, who seized control of much of the country earlier this year. Henry Ridgwell reports.
Video

Video Apps Helping Kenyan Businesses Stay Ahead of Counterfeiters

Counterfeit goods in Kenya cost the government as much as $1 billion each year in lost tax revenues. The fake goods also hurt entrepreneurs who find it hard to carve out a niche in the market and retain customers. But as Lenny Ruvaga reports from Nairobi, information technology is being used to try to beat the problem.
Video

Video Nobel Prize Winner Malala Talks to VOA

Nobel Peace Prize winner Malala Yousafzai met with VOA's Deewa service in Washington Sunday to talk about women’s rights and unveil a trailer for her new documentary. VOA's Katherine Gypson has more.
Video

Video War, Drought Threaten Iraq's Marshlands

Iraq's southern wetlands are in crisis. These areas are the spawning ground for Gulf fisheries, a resting place for migrating wildfowl, and source of livelihood for fishermen and herders. Faith Lapidus has more.
Video

Video Colombians Flee Venezuela as Border Crisis Escalates

Hundreds of Colombians have fled Venezuela since last week, amid an escalating border crisis between the two countries. Last week, Venezuelan President Nicolas Maduro ordered the closure of a key border crossing after smugglers injured three Venezuelan soldiers and a civilian. The president also ordered the deportation of Colombians who are in Venezuela illegally. Zlatica Hoke reports.
Video

Video Rebuilding New Orleans' Music Scene

Ten years after Hurricane Katrina inundated New Orleans, threatening to wash away its vibrant musical heritage along with its neighborhoods, the beat goes on. As Bronwyn Benito and Faith Lapidus report, a Musicians' Village is preserving the city's unique sound.
Video

Video In Russia, Auto Industry in Tailspin

Industry insiders say country relies too heavily on imports as inflation cuts too many consumers out of the market. Daniel Schearf has more from Moscow.
Video

Video Scientist Calls Use of Fetal Tissue in Medical Research Essential

An anti-abortion group responsible for secret recordings of workers at a women's health care organization claims the workers shown are offering baby parts for sale, a charge the organization strongly denies. While the selling of fetal tissue is against the law in the United States, abortion and the use of donated fetal tissue for medical research are both legal. VOA’s Julie Taboh reports.

VOA Blogs