Digest this: Cure for cancer may live in our intestines

July 31, 2013
The discovery of Robo1 protein in the intestinal stem cells (depicted in yellow) leads to tolerance of higher doses of chemoradiation for cancer patients. Image courtesy Dr. Wei-Jie Zhou.

Treating a cancerous tumor is like watering a houseplant with a fire hose—too much water kills the plant, just as too much chemotherapy and radiation kills the patient before it kills the tumor.

However, if the patient's gastrointestinal tract remains healthy and functioning, the patient's chances of survival increase exponentially, said Jian-Guo Geng, associate professor at the University of Michigan School of Dentistry. Recently, Geng's lab discovered a that preserves the gastrointestinal tracts in mice who were delivered lethal doses of chemotherapy.

The findings, which will appear in the journal Nature, could revolutionize , Geng said.

"It's our belief that this could eventually cure later-staged metastasized cancer. People will not die from cancer, if our prediction is true," said Geng, who emphasized that the findings had not yet been proven in humans. "All tumors from different tissues and organs can be killed by high doses of chemotherapy and radiation, but the current challenge for treating the later-staged metastasized cancer is that you actually kill the patient before you kill the tumor.

"Now you have a way to make a patient tolerate to lethal doses of chemotherapy and . In this way, the later-staged, metastasized cancer can be eradicated by increased doses of chemotherapy and radiation."

Geng's lab found that when certain proteins bind with a specific molecule on intestinal stem cells, it revs intestinal stem cells into overdrive for intestinal regeneration and repair. Stem cells naturally heal damaged organs and tissues, but so-called "normal" amounts of stem cells in the simply cannot keep up with the wreckage left behind by the lethal doses of chemotherapy and radiation required to successfully treat late-stage tumors.

However, the phalanx of extra stem cells protect the intestine and , which means the patient can ingest nutrients, the body can perform other critical functions and the bacterial toxins in the intestine are prevented from entering the blood circulation, Geng said.

These factors could give the patient just enough of an extra edge to survive the stronger doses of chemotherapy and radiation, until the tumor or tumors are eradicated.

In the study, 50-to-75 percent of the mice treated with the molecule survived otherwise lethal doses of chemotherapy. All of the mice that did not receive the molecule died, Geng said.

"If you can keep the gut going, you can keep the patient going longer," Geng said. "Now we have found a way to protect the intestine. The next step is to aim for a 100-percent survival rate in mice who are injected with the molecules and receive lethal doses of chemotherapy and radiation."

Geng's lab has worked with these molecules, called R-spondin 1 and Slit2, for more than a decade. These molecules repair tissue in combination with intestinal residing in the adult intestine.

Explore further: New immune therapy treats brain tumors in mice

More information: Induction of intestinal stem cells by R-spondin 1 and Slit2 augments chemoradioprotection, Nature, DOI: 10.1038/nature12416

Related Stories

New immune therapy treats brain tumors in mice

December 17, 2012

Using an artificial protein that stimulates the body's natural immune system to fight cancer, a research team at Duke Medicine has engineered a lethal weapon that kills brain tumors in mice while sparing other tissue. If ...

Study reveals that chemotherapy works in an unexpected way

April 4, 2013

It's generally thought that anticancer chemotherapies work like antibiotics do, by directly killing off what's harmful. But new research published online on April 4 in the Cell Press journal Immunity shows that effective ...

Pretesting cervical tumors could inform treatment

May 31, 2013

(Medical Xpress)—Doctors at Washington University School of Medicine in St. Louis have shown that testing cervical tumors before treatment for vulnerability to chemotherapy predicts whether patients will do well or poorly ...

Recommended for you

Forecasting the path of breast cancer in a patient

November 23, 2015

USC researchers have developed a mathematical model to forecast metastatic breast cancer survival rates using techniques usually reserved for weather prediction, financial forecasting and surfing the Web.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

2 / 5 (4) Jul 31, 2013
Yes, but um, what about the microbes? ... The gut is more than just a biomolecular machine. It's also an ecology of living microbes.

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.