Dieting may decrease chances for metastases in triple negative breast cancers by strengthening the tissue surrounding the tumor
Calorie restriction, a kind of dieting in which food intake is decreased by a certain percentage, has been touted as way to help people live longer. New research suggests that there may be other benefits, including improving outcomes for women in breast cancer. According to a study published May 26th in Breast Cancer Research and Treatment, the triple negative subtype of breast cancer – one of the most aggressive forms – is less likely to spread, or metastasize, to new sites in the body when mice were fed a restricted diet.
"The diet turned on a epigenetic program that protected mice from metastatic disease," says senior author Nicole Simone, M.D., an associate professor in the department of Radiation Oncology at Thomas Jefferson University. Indeed, when mouse models of triple negative cancer were fed 30 percent less than what they ate when given free access to food, the cancer cells decreased their production of microRNAs 17 and 20 (miR 17/20). Researchers have found that this group of miRs is often increased in triple negative cancers that metastasize.
Breast cancer patients are often treated with hormonal therapy to block tumor growth, and steroids to counteract the side effects of chemotherapy. However, both treatments can cause a patient to have altered metabolism which can lead to weight gain. In fact, women gain an average of 10 pounds in their first year of treatment. Recent studies have shown that too much weight makes standard treatments for breast cancer less effective, and those who gain weight during treatment have worse cancer outcomes. "That's why it's important to look at metabolism when treating women with cancer," says Dr. Simone.
In earlier studies, Dr. Simone and colleagues had shown that calorie restriction boosted the tumor-killing effects of radiation therapy. This study aimed to examine which molecular pathways were involved in this cooperative effect.
The investigators noticed that microRNAs – a type of RNA that regulates other genes in the cell – specifically miR 17 and 20, decreased the most when mice were treated with both radiation and calorie restriction. This decrease in turn increased the production of proteins involved in maintaining the extracellular matrix. "Calorie restriction promotes epigenetic changes in the breast tissue that keep the extracellular matrix strong," says Dr. Simone. "A strong matrix creates a sort of cage around the tumor, making it more difficult for cancer cells to escape and spread to new sites in the body."
Understanding the link to miR 17 also gives researchers a molecular target for diagnosing cancers that are more likely to metastasize and, potentially, for developing a new drug to treat the cancers. In theory, a drug that decreased miR 17 could have the same effect on the extracellular matrix as calorie restriction. However, targeting a single molecular pathway, such as the miR17 is unlikely to be as effective as calorie restriction, says Dr. Simone. Triple negative breast cancers tend to be quite different genetically from patient to patient. If calorie restriction is as effective in women as it is in animal models, then it would likely change the expression patterns of a large set of genes, hitting multiple targets at once without toxicity.
In order to test that this hypothesis is true in humans, Dr. Simone is currently enrolling patients in the CaReFOR (Calorie Restriction for Oncology Research) trial. As the first trial like it in the country, women undergoing radiation therapy for breast cancer receive nutritional counseling and are guided through their weight loss plan as they undergo their treatment for breast cancer.
The authors declare no conflicts of interest.
The study was funded by the NCI Cancer Center Support Grant P30-CA56036 for the Kimmel Cancer Center.
For more information, please contact Edyta Zielinska, email@example.com, 215-955-5291
Article reference: L. Jin, et al., "The metastatic potential of triple-negative breast cancer is decreased via caloric restriction-mediated reduction of the miR-17~92 cluster," Breast Cancer Res Treat, DOI 10.1007/s10549-014-2978-7, 2014.
Thomas Jefferson University (TJU), the largest freestanding academic medical center in Philadelphia, is nationally renowned for medical and health sciences education and innovative research. Founded in 1824, TJU includes Jefferson Medical College (JMC), one of the largest private medical schools in the country and ranked among the nation's best medical schools by U.S. News & World Report, and the Jefferson Schools of Nursing, Pharmacy, Health Professions, Population Health and the Graduate School of Biomedical Sciences. Jefferson University Physicians is TJU's multi-specialty physician practice consisting of the full-time faculty of JMC. Thomas Jefferson University partners with its clinical affiliate, Thomas Jefferson University Hospitals.
Edyta Zielinska | Eurek Alert!
Fiber optic biosensor-integrated microfluidic chip to detect glucose levels
29.04.2016 | The Optical Society
Got good fat?
27.04.2016 | Rheinische Friedrich-Wilhelms-Universität Bonn
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...
As one of the leading R&D partners in the development of surface technologies and organic electronics, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will be exhibiting its recent achievements in vacuum coating of ultra-thin glass at SVC TechCon 2016 (Booth 846), taking place in Indianapolis / USA from May 9 – 13.
Fraunhofer FEP is an experienced partner for technological developments, known for testing the limits of new materials and for optimization of those materials...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
29.04.2016 | Physics and Astronomy
29.04.2016 | Health and Medicine
29.04.2016 | Life Sciences