April 24, 2006
Microfluidic Device Enables Protein Analysis in Single Cancer Cells
A microfluidic device designed to slow the movement of specific subsets of cells has shown potential for use in characterizing the multiple types of cells found within human tumors. Such a device could help cancer researchers better understand the heterogeneity that develops in a tumor and provide important diagnostic information that could enable oncologists to better design therapies for a given patient. This work was published in the journal Clinical Chemistry.
Robert Wieder, Ph.D., and his colleagues at the University of Medicine and Dentistry of New Jersey, developed their device to test the hypothesis that different types of cells could be separated from one another based on their ability to bind to targeting molecules attached to the walls of a microfluidics channel. To do so, the researchers treated glass microfluidic channels in such a way as to enable these molecular targets, or ligands, to bind tightly to the glass surface even when exposed to fluid flowing over that surface. In the reported experiments, the researchers used an antibody to the cell-surface protein known as integrin α5β1, which is found on the outer membrane of some types of breast cancer cells, as the targeting molecule.
Using cultured breast cancer cells, the investigators showed that those cells expressing integrin α5β1 moved more slowly through the microfluidics channels than did cells lacking that integrin. Movements of the two populations of cells 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 microfluidics device. Using this detection system, the investigators 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 note that the design of their device should enable 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 will also 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.
This work is detailed in a paper titled, “Microfluidic techniques for single-cell protein expression analysis.” Investigators from Rider University in Lawrenceville, NJ, and the Sarnoff Corporation in Princeton, NJ, also participated in this study. An abstract of this paper is available through PubMed.