FRESH SCIENCE for Clinicians

News about basic science of interest and relevance for cancer clinicians

Friday, December 21, 2012

A Force of Nature

Although the annual meeting of the American Society for Cell Biology is unlikely to be on the travel schedule for most oncologists, researchers there presented studies that cancer scientists may find interesting.


In the first study, Gautham Venugopalan, a graduate student in the lab of Daniel Fletcher at the University of California, Berkeley, reported that a brief compressive force triggers a major morphological change in breast cancer cells (abstract 1673).


When grown in a 3-dimensional matrix under normal conditions, malignant epithelial cells from disorganized colonies. However, if the researchers subject the malignant cells to a compressive force, the cells rotate and form normal-looking acini.


Venugopalan says that about 10 minutes of force in the beginning of a 10-day experiment is enough to trigger the change. The force itself is ~5kPa (< 1psi). “That is about 5% of what you would fill up a regular party balloon with,” he said.


The investigators are not sure how the force causes the change, but they are currently looking at gene expression patterns to see if force-treated breast cancer cells return to a more normal pattern compared to untreated control cells.


When asked how these findings might translate into patient treatment in the future, Venugopalan says their work is about understanding how cells sense their environment and form organized structures. “If we know which key structures and molecules are involved in forming organized structures, we would have a new set of potential targets for cancer treatment and therapy,” he said.


In a second, unrelated abstract, Mark LaBarge, PhD, from the Lawrence Berkeley National Laboratory, and colleagues report that the relative abundance of different types of breast epithelial cells shifts as women age (abstract 1674).


Dr. LaBarge and colleagues have assembled a large collection of breast tissue samples from healthy women aged 16 to 91 years — a collection called the human mammary epithelial cell (HMEC) Aging Resource.


Comparing uncultured samples from younger and older women, the investigators found that the proportion of myoepithelial cells declines with age, whereas the proportion of luminal cells increases.


Moreover, as women age, the number of defective progenitor cells increases, giving rise to a larger number of partially differentiated luminal and myoepithelial cells. That increase, according to Dr. LaBarge, may leave older women more susceptible to breast cancer – and may partially explain why such a large proportion of breast cancer cases occur in women over the age of 50.


And for oncologists who didn’t make it the Cell Biology meeting, LaBarge and colleagues reported the full study in Cancer Research earlier this year.