NEWARK—A new microscopic device that sorts out tumors according to specific proteins on the surfaces of malignant tumor cells may help researchers characterize cancer cells to better understand tumor behavior and ensure more accurate patient treatment, says an oncology researcher at the University of Medicine and Dentistry of New Jersey who developed the device.

Dr. Robert Wieder, a physician/scientist at the UMDNJ-New Jersey Medical School in Newark and a team of researchers, developed their device to identify different types of cells for their ability to transiently bind to targeting molecules attached to the walls of a device called a microfluidic channel. The channel identifies different types of cells based on their ability to temporarily bind with target molecules on its walls.

"This technology does not require any special preparation of the cells and will be ideal for characterizing tumor cells even if only a few are available," Dr. Wieder said. His research is published in the June issue of the journal Clinical Chemistry.

The device was created to slow the movement of cells in the flow channel. Researchers may now be able to characterize the multiple cell types in a tumor that cannot currently be characterized by researchers, meaning cancer researchers will be able to better understand the heterogeneity that develops in a tumor and provide important diagnostic information that may result in improved design of treatment for patients.

In testing their hypothesis, the researchers treated glass microfluidic channels in such a way that enable molecular targets, or ligands, to bind tightly to the glass surface, even when exposed to fluids. In the reported experiments in the journal article, Dr. Wieder and his colleagues used a specific antibody to a cell-surface protein found on the outer membrane of certain types of breast cancer cells, as the targeting molecule.

Using cultured breast cancer cells, the investigators showed that those cells expressing specific surface proteins, called integrins, moved more slowly through the microfluidic channels to these integrins than did cells moving through channels coated with non-specific proteins. Movements of cells past these two areas of the channel were tracked using a video camera and video tracking software that can account for hundreds of individual cells as they move through the various regions of the microfluidic device.

Using this detection system, Dr. Wieder and his associates were able to eliminate the typical experimental step of tagging or labeling the cells with an optical marker, such as a fluorescent molecule, simplifying the overall procedure significantly.

The researchers noted that the design of their device should allow them to separate and characterize multiple cell populations by using more than one targeting ligand in a single device. The investigators believe that their device also will work with cells isolated directly from patient tissue samples with little, if any, preparation other than separating a mass of cells, such as those taken from a tumor or other tissue sample, into its individual cells.

Contact: Tom Capezzuto
capezzta@umdnj.edu