Diagnosing disease by squeezing cells

Cells are the basic units of life that all organisms, albeit in different shapes, are based on. Human bodies contain trillions of cells and are unimaginably complex, with a sheer endless stream of different proteins inside the cell, each with their own function. If our cells are diseased, we suffer from the consequences, but diagnosis is mostly performed on a higher level: cells form tissues and organs, and clinicians focus primarily on looking at the overall function of the tissue. Scientists from the University of California in Los Angeles have found a way to use individual cells as markers for disease, by squeezing them.

Sack of fluid
Cells are basically very small bulbs filled with loads of liquid holding molecules in suspension. Animal cells do not possess cell walls that keep them in a rigid shape, such as the ones plant cells have. Instead, they are covered by a fatty membrane that can easily change shape, resembling the structural rigidity of a balloon. Therefore, cells can be flattened, squeezed and bend at will. According to the Californian scientists, the way a cell deforms after manipulating it tells us something about disease.

Measurements
The viscosity of the cellular fluid can change when a cell is diseased, which means it would deform in a different way, much like the difference between a balloon filled with water or honey. What the scientists did is create the equivalent of hitting a wall with a balloon, and then determine how it deformed after impact. From the patterns, researchers are able to assess whether measured cells are still healthy. Using a so-called deformability cytometer, that takes 140.000 pictures per second, cells were smashed into a wall to analyse how they change in shape.

Time-lapse showing how cells get squeezed into a different shape after hitting a wall.

Results
Using their machine, scientists were able to correctly identify cancer in a mixture of lung cells. Even though a wide variety of different cells are found in the pleural tissue of the lung, the deformability cytometer was able to spot the bad ones. The scientists also showed it is possible to distinguish different types of cells based on their squeezing pattern, after they hit the 'wall'. Because the machine is able to process tens of thousands of cells per 10 to 30 minutes, clinicians can quickly scan through the patient's tissue to find culprits of disease.

Outlook
Because it can be hard to detect small anomalies in tissues and cells based on morphology or general tissue function, a deformability cytometer can help clinicians detect otherwise unnoticed signs of disease. Examples include tissues where the concentration of diseased cells, in particular some forms of tumours, is very low. High throughput of individual cells renders it possible to find those individual cells that, even though low in number, can deteriorate the patient's health.