After probing a cell, the AFM assigns a value that represents how soft a cell is based on the resistance encountered. The researchers found that the cancer cells are much softer than normal cells, which come in varying degrees of stiffness. This was true of all the pancreas, lung and breast cells studied.
Rao and his colleagues want to use the touchy-feely AFM to test primary tumors for malignancy and study how different cancers behave. "Some tumor cells might be more rigid than others, meaning that they may be less metastatic," and thereby the patient is in less danger, Rao says.
Looking ahead, the AFM is most likely to be used not as an initial detection tool, but rather as a means of checking whether cancer is spreading or in remission. Fluid buildup is not necessarily an indication of cancer, so understanding the nature of the cells in this fluid is very important to determining possible treatments, according to the scientists. "We have to check the fluid to see if it's positive for cancer," Rao says, "because this can determine if a treatment needs to be more aggressive."
U.C.L.A. researchers are also using the AFM to study the effects of different drugs on cancer cells. "We want to see how cells change with the drugs that we use on them," says study co-author Sarah Cross, a U.C.L.A. graduate student in the chemistry and biochemistry department. The goal is to develop less toxic drugs than currently available to stop normal cells from becoming cancerous, thus stopping the deadly spread of the disease.