Public release date: 13-Feb-2012
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Contact: Kim Irwin
kirwin@mednet.ucla.edu
310-206-2805
University of California - Los Angeles Health Sciences

Breast cancer stem cells are thought to be the sole source of tumor recurrence and are known to be resistant to radiation therapy and don't respond well to chemotherapy.

Now, researchers with the UCLA Department of Radiation Oncology at UCLA's Jonsson Comprehensive Cancer Center report for the first time that radiation treatment ?despite killing half of all tumor cells during every treatment - transforms other cancer cells into treatment-resistant breast cancer stem cells.

The generation of these breast cancer stem cells counteracts the otherwise highly efficient radiation treatment. If scientists can uncover the mechanisms and prevent this transformation from occurring, radiation treatment for breast cancer could become even more effective, said study senior author Dr. Frank Pajonk, an associate professor of radiation oncology and Jonsson Cancer Center researcher.

"We found that these induced breast cancer stem cells (iBCSC) were generated by radiation-induced activation of the same cellular pathways used to reprogram normal cells into induced pluripotent stem cells (iPS) in regenerative medicine," said Pajonk, who also is a scientist with the Eli and Edythe Broad Center of Regenerative Medicine at UCLA. "It was remarkable that these breast cancers used the same reprogramming pathways to fight back against the radiation treatment."

The study appears February 13, 2012 in the early online edition of the peer-reviewed journal Stem Cells.

"Controlling the radiation resistance of breast cancer stem cells and the generation of new iBCSC during radiation treatment may ultimately improve curability and may allow for de-escalation of the total radiation doses currently given to breast cancer patients, thereby reducing acute and long-term adverse effects," the study states.

There are very few breast cancer stem cells in a larger pool of breast cancer cells. In this study, Pajonk and his team eliminated the smaller pool of breast cancer stem cells and then irradiated the remaining breast cancer cells and placed them into mice.

Using a unique imaging system Pajonk and his team developed to visualize cancer stem cells, the researchers were able to observe their initial generation into iBCSC in response to the radiation treatment. The newly generated iBCSC were remarkably similar to breast cancer stem cells found in tumors that had not been irradiated, Pajonk said.

The team also found that the iBCSC had a more than 30-fold increased ability to form tumors compared to the non-irradiated breast cancer cells from which they originated.

Pajonk said that the study unites the competing models of clonal evolution and the hierarchical organization of breast cancers, as it suggests that undisturbed, growing tumors maintain a small number of cancer stem cells. However, if challenged by various stressors that threaten their numbers, including ionizing radiation, the breast cancer cells generate iBCSC that may, together with the surviving cancer stem cells, repopulate the tumor.

"What is really exciting about this study is that it gives us a much more complex understanding of the interaction of radiation with cancer cells that goes far beyond DNA damage and cell killing," Pajonk said. "The study may carry enormous potential to make radiation even better."

Pajonk stressed that breast cancer patients should not be alarmed by the study findings and should continue to undergo radiation if recommended by their oncologists.

"Radiation is an extremely powerful tool in the fight against breast cancer," he said. "If we can uncover the mechanism driving this transformation, we may be able to stop it and make the therapy even more powerful."

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This study was funded by the National Cancer Institute, the California Breast Cancer Research Program and the Department of Defense. UCLA's Jonsson Comprehensive Cancer Center has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation's largest comprehensive cancer centers, the Jonsson center is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2011, the Jonsson Cancer Center was named among the top 10 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 11 of the last 12 years. For more information on the Jonsson Cancer Center, visit our website at http://www.cancer.ucla.edu.

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Radiation treatment transforms breast cancer cells into cancer stem cells

Heart-Attack Damage Heals After Stem Cell Treatment

Feb. 13, 2012 -- A new stem cell treatment resurrects dead, scarred heart muscle damaged by a recent heart attack.

The finding, just in time for Valentine's Day, is the clearest evidence yet that literally broken hearts can heal. All that's needed is a little help from one's own heart stem cells.

"We have been trying as doctors for centuries to find a treatment that actually reverses heart injury," Eduardo Marban, MD, PhD, tells WebMD. "That is what we seem to have been able to achieve in this small number of patients. If so, this could change the nature of medicine. We could go to the root of disease and cure it instead of just work around it."

Marban, director of the Cedars-Sinai Heart Institute in Los Angeles, led the study. He invented the "cardiosphere" culture technique used to create the stem cells and founded the company developing the treatment.

It's the first completed, controlled clinical trial showing that scarred heart tissue can be repaired. Earlier work in patients with heart failure, using different stem cells or bone-marrow stem cells, also showed that the heart can regenerate itself.

"These findings suggest that this therapeutic approach is feasible and has the potential to provide a treatment strategy for cardiac regeneration after [heart attack]," write University of Hong Kong researchers Chung-Wah Siu and Hung-Fat Tse. Their editorial accompanies the Marban report in the Feb. 14 advance online issue of The Lancet.

Heart Regenerates With Stem Cell Help

The stem cells don't do what people think they do, Marban says.

It's been thought that the stem cells multiply over and over again. In time, they were supposed to be turning themselves and their daughter cells into new, working heart muscle.

But the stem cells seem to be doing something much more amazing.

"For reasons we didn't initially know, they stimulate the heart to fix itself," Marban says. "The repair is from the heart itself and not from the cells we give them."

Exactly how the stem cells do this is a matter of "feverish research" in Marban's lab.

The phase I clinical trial enrolled 25 patients who had just had a heart attack. On average, each patient had lost a quarter of his heart muscle. MRI scans showed massive scars.

Eight patients got standard care. The other 17 received increasing infusions of what Marban calls stem cells. The cells were grown in the lab from tiny amounts of heart cells taken from the patients' own hearts via biopsy. Six to 12 weeks later, the cells were infused directly back into patients' hearts.

A year later, the mass of scar tissue in the treated patients' hearts got 42% smaller. And healthy heart muscle increased by 60%. No such regeneration was seen in the patients who got standard care.

Because all of the patients were doing relatively well, there was no dramatic difference in clinical outcome. However, treated patients had a bit better exercise endurance.

"This discovery challenges the conventional wisdom that, once established, cardiac scarring is permanent and that, once lost, healthy heart muscle cannot be restored," Marban and colleagues conclude.

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Scarred Hearts Healed After Heart Attack

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Watch: Can Stem Cells Regenerate a Weak Heart?

Stem cells grown from patients’ own cardiac tissue can heal damage once thought to be permanent after a heart attack, according to a study that suggests the experimental approach may one day help stave off heart failure.

In a trial of 25 heart-attack patients, 17 who got the stem cell treatment showed a 50 percent reduction in cardiac scar tissue compared with no improvement for the eight who received standard care. The results, from the first of three sets of clinical trials generally needed for regulatory approval, were published today in the medical journal Lancet.

“The findings in this paper are encouraging,” Deepak Srivastava, director of the San Francisco-based Gladstone Institute of Cardiovascular Disease, said in an interview. “There’s a dire need for new therapies for people with heart failure, it’s still the No. 1 cause of death in men and women.”

The study, by researchers from Cedars-Sinai Heart Institute in Los Angeles and Johns Hopkins University (43935MF) in Baltimore, tested the approach in patients who recently suffered a heart attack, with the goal that repairing the damage might help stave off failure. While patients getting the stem cells showed no more improvement in heart function than those who didn’t get the experimental therapy, the theory is that new tissue regenerated by the stem cells can strengthen the heart, said Eduardo Marban, the study’s lead author.

“What our trial was designed to do is to reverse the injury once it’s happened,” said Marban, director of Cedars- Sinai Heart Institute. “The quantitative outcome that we had in this paper is to shift patients from a high-risk group to a low- risk group.”

Minimally Invasive

The stem cells were implanted within five weeks after patients suffering heart attacks. Doctors removed heart tissue, about the size of half a raisin, using a minimally invasive procedure that involved a thin needle threaded through the veins. After cultivating the stem cells from the tissue, doctors reinserted them using a second minimally invasive procedure. Patients got 12.5 million cells to 25 million cells.

A year after the procedure, six patients in the stem cell group had serious side effects, including a heart attack, chest pain, a coronary bypass, implantation of a defibrillator, and two other events unrelated to the heart. One of patient’s side effects were possibly linked to the treatment, the study found.

While the main goal of the trial was to examine the safety of the procedure, the decrease in scar tissue in those treated merits a larger study that focuses on broader clinical outcomes, researchers said in the paper.

Heart Regeneration

“If we can regenerate the whole heart, then the patient would be completely normal,” Marban said. “We haven’t fulfilled that yet, but we’ve gotten rid of half of the injury, and that’s a good start.”

While the study resulted in patients having an increase in muscle mass and a shrinkage of scar size, the amount of blood flowing out of the heart, or the ejection fraction, wasn’t different between the control group and stem-cell therapy group. The measurement is important because poor blood flow deprives the body of oxygen and nutrients it needs to function properly, Srivastava said.

“The patients don’t have a functional benefit in this study,” said Srivastava, who wasn’t not involved in the trial.

The technology is being developed by closely held Capricor Inc., which will further test it in 200 patients for the second of three trials typically required for regulatory approval. Marban is a founder of the Los Angeles-based company and chairman of its scientific advisory board. His wife, Lisa Marban, is also a founder and chief executive officer.

To contact the reporter on this story: Ryan Flinn in San Francisco at rflinn@bloomberg.net

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net

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Scarred Hearts Can Be Mended With Novel Stem Cell Therapy, Study Finds

Dr. Eduardo Marbán, in his laboratory at the Cedars-Sinai Heart Institute. (Cedars-Sinai Heart Institute)

By Eryn Brown, Los Angeles Times / for the Booster Shots blog

February 13, 2012, 5:45 p.m.

Researchers have used cardiac stem cells to regenerate heart muscle in patients who have suffered heart attacks, also known as myocardial infarction.

The small preliminary study, which was conducted by the Cedars-Sinai Heart Institute in Los Angeles, involved 25 patients who had suffered heart attacks in the previous one and a half to three months. 

Seventeen of the study subjects received infusions of stem cells cultured from a raisin-sized chunk of their own heart tissue, which had been removed via catheter. The eight others received standard care. 

During a heart attack, heart tissue is damaged, leaving a scar.  On average, scars in patients who had the stem cell infusions dropped in size from 24% to 12% of the heart, said Dr. Eduardo Marbán, director of the Cedars-Sinai Heart Institute and lead researcher on the study, which was published online Monday in the journal The Lancet.  (The journal has provided an abstract of the study; subscription is required for the full text.)

In an email, Marbán said he believed that the stem cells repaired the damaged heart muscle "indirectly, by stimulating the heart's endogenous capacity to regrow [which normally lies dormant]." He said that the most surprising aspect of the research team's finding was that the heart was able to regrow healthy tissue. Conventional wisdom holds that cardiac scarring is permanent.

A follow-up study involving about 200 patients is planned for later this year, Marbán added.

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Study: Cardiac stem cells can reverse heart attack damage

13 February 2012 Last updated at 19:52 ET By James Gallagher Health and science reporter, BBC News

Damage caused by a heart attack has been healed using stem cells gathered from the patient's own heart, according to doctors in the US.

The amount of scar tissue was halved in the small safety trial reported in the Lancet medical journal.

The authors said there was also an "unprecedented" increase in new heart muscle.

The British Heart Foundation said it was "early days", but could "be great news for heart attack patients".

A heart attack happens when the organ is starved of oxygen, such as a clot blocking the flow of blood to the heart.

As the heart heals, the dead muscle is replaced with scar tissue, but because this does not beat like heart muscle the ability to pump blood around the body is reduced.

Doctors around the world are looking at ways of "regenerating" the heart to replace the scar tissue with beating muscle. Stem cells, which can transform into any other type of specialised cell, figure prominently in their plans.

Heart to heart

This trial, at the Cedars-Sinai Heart Institute, was designed to test the safety of using stem cells taken from a heart attack patient's own heart.

Continue reading the main story Healing the heart

This is the second group of doctors to report using cells taken from a heart to heal a heart.

In November 2011, another safety trial showed the cells could be used to heal the hearts of heart failure patients who were having heart bypass surgery.

The heart is not the only source for these stem cells and other fields are much further ahead.

The largest ever trial of stem cell therapy in heart attack patients is about to get under way in Europe.

The BAMI trial will inject 3,000 heart attack patients with stem cells taken from their bone marrow within five days of the heart attack.

Within a month of a heart attack, a tube was inserted into a vein in the patient's neck and was pushed down towards the heart. A sample of heart tissue, about "half the size of a raisin", was taken.

This was taken to the laboratory where the stem cells were isolated and grown. Up to 25 million of these stem cells were then put into the arteries surrounding the heart.

Twenty five patients took part in the trial. Before the treatment, scar tissue accounted for an average of 24% of their left ventricle, a major chamber of the heart. It went down to 16% after six months and 12% after a year.

Healthy heart muscle appeared to take its place. The study said the cells, "have an unprecedented ability to reduce scar and simultaneously stimulate the regrowth of healthy [heart] tissue".

One of the researchers Dr Eduardo Marban said: "While the primary goal of our study was to verify safety, we also looked for evidence that the treatment might dissolve scar and regrow lost heart muscle.

"This has never been accomplished before, despite a decade of cell therapy trials for patients with heart attacks. Now we have done it.

Continue reading the main story “Start Quote

These cells have been proven to form heart muscle in a Petri dish but now they seem to be doing the same thing when injected back into the heart as part of an apparently safe procedure”

End Quote Prof Jeremy Pearson British Heart Foundation

"The effects are substantial, and surprisingly larger in humans than they were in animal tests."

However, there was no increase in a significant measure of the heart's ability to pump - the left ventricle ejection fraction: the percentage of blood pumped out of the left ventricle.

Prof Anthony Mathur, who is co-ordinating a stem cell trial involving 3,000 heart attack patients, said that even if the study found an increase in ejection fraction then it would be the source of much debate.

He argued that as it was a proof-of-concept study, with a small group of patients, "proving it is safe and feasible is all you can ask".

"The findings would be very interesting, but obviously they need further clarification and evidence," he added.

Prof Jeremy Pearson, associate medical director at the British Heart Foundation, said: "It's the first time these scientists' potentially exciting work has been carried out in humans, and the results are very encouraging.

"These cells have been proven to form heart muscle in a petri dish but now they seem to be doing the same thing when injected back into the heart as part of an apparently safe procedure.

"It's early days, and this research will certainly need following up, but it could be great news for heart attack patients who face the debilitating symptoms of heart failure."

The rest is here:
Cells 'heal' heart attack scars