Women who are obese have a higher risk and a worse prognosis for breast cancer, but the reasons why remain unclear. A Cornell study published this month in Science Translational Medicine explains how obesity changes the consistency of breast tissue in ways that are similar to tumors, thereby promoting disease.
The study of mice and women shows obesity leads to a stiffening of a meshwork of material that surrounds fat cells in the breast, called the extracellular matrix, and these biomechanical changes create the right conditions for tumor growth.
The findings suggest clinicians may need to employ finer-scale imaging techniques in mammograms, especially for obese women, to detect a denser extracellular matrix. Also, the results should caution doctors against using certain fat cells from obese women in plastic and reconstructive breast surgeries, as these cells can promote recurring breast cancer.
"We all know that obesity is bad; the metabolism changes and hormones change, so when looking for links to breast cancer, researchers almost exclusively have focused on the biochemical changes happening. But what these findings show is that there are also biophysical changes that are important," said Claudia Fischbach, associate professor of biomedical engineering and the paper's senior author. Bo Ri Seo, a graduate student in Fischbach's lab, is the paper's first author.
The study is a collaboration between Cornell's Ithaca campus and researchers at Weill Cornell Medical College and includes Dr. Andrew Dannenberg, professor of medicine.
Fat tissue in obese women has more cells called myofibroblasts, compared with fat tissue in normal-weight women. Myofibroblasts are wound-healing cells that determine whether a scar will form. All cells secrete compounds to create an extracellular matrix, and they remodel and grab onto this meshwork to make tissue. But when myofibroblasts make an extracellular matrix, they pull together - the action needed to close a wound - stiffening the tissue.
But "these are cells in our body regardless of injury," said Fischbach. In obese women, there are more myofibroblasts than in lean women, which leads to scarring and stiffening without an injury in the extracellular matrix. Tumors also recruit more myofibroblasts than are found in healthy tissue, which also leads to stiffer extracellular matrix.
Many obese women get regular mammograms but signs of disease don't show up because detecting their dense extracellular matrix between the fat cells requires a finer-scale resolution. The findings "may inspire use of higher resolution imaging techniques to detect those changes," said Fischbach. "Right now, people don't look for stiffer extracellular matrices as a clinical biomarker."
During plastic or reconstructive surgery following mastectomy in breast cancer patients, doctors may inject adipose stromal cells from obese donors to regenerate tissue. "What our data suggests is that it is really important where these cells are being taken from," Fischbach said. "If you use these cells from an obese patient, they are very different and you may actually be driving malignancies if you implant them."
The study was funded by the National Institutes of Health, the National Science Foundation, the Breast Cancer Research Foundation and the Botwinick-Wolfensohn Foundation at WCMC.
Cornell University has television, ISDN and dedicated Skype/Google+ Hangout studios available for media interviews.
Melissa Osgood | EurekAlert!
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy