Cancer cells tend to be much softer, or more elastic, than normal cells, and measuring this characteristic on the nanometer scale could be another way to diagnose cancer. Dr. James Gimzewski of the California NanoSystems Institute, collaborating with Dr. Jian Yu Rao of UCLA' Jonsson Comprehensive Cancer Center, profiled the elasticity of live metastatic cancer cells and normal cells from patients' body fluids using atomic force microscopy. The researchers could distinguish between normal and cancerous cells based on their physical characteristics, according to findings published online December 2 in Nature Nanotechnology.

"Measuring the physical features of cancer cells adds another dimension to the analysis of these cells and could help us diagnose the disease, " says Dr. Rao. Unlike normal cells, cancer cells are more flexible and can move through holes and spaces easily, which is how they enter the bloodstream and spread to other organs, according to Dr. Rao. "This is a major reason cancer is so deadly, " he adds.

The researchers tested fluids from patients with suspected metastatic lung, breast, or pancreatic cancer. Each patient sample contained both normal and cancerous cells, allowing the researchers to directly compare the physical characteristics of the cells. The cancerous cells were found to be more than 70 percent softer than the benign cells, based on measurements of cell stiffness at the nanometer scale. The cancerous cells showed a similar physical signature that was distinct from normal cells, even though the patients had different tumor types.