New device to quickly separate cancer cells from normal ones

Researchers led by The Methodist Hospital in US tested the device 'Mechanical Separation Chip' or MS-Chip with different kinds of cancer cells.

Cells separated by the device can be easily collected and studied, researchers said.

The current standard for cell separation, flow cytometry, is relatively slow and relies on cell surface biomarkers.

"Our microfluidics cell separation via MS-Chip provides a high throughput method that can particularly sort cells to different levels of stiffness, which opens a new avenue to study stiffness related cellular and molecular biology," said Methodist nanomedical faculty Lidong Qin, the project's principal investigator.

The study with new device found that more flexible, tumour-causing cells navigated a gamut of tiny barriers, whereas the more rigid, more benign cells had trouble squeezing through 7 micrometre holes.

The work supports the hypothesis that cell squishiness indicates tumour potential. Most normal cells contain a developed cytoskeleton - a network of tiny but strong rod-shaped proteins that give cells their shape and structure.

In their feverish drive to divide, cancer cells may be diverting resources away from developing a cytoskeleton in favour of division, hence the squishiness.

"We have created many pathways for cells to cross barriers," said Qin.

"The throughput of a MS-Chip is at the level of one million cells. When a stiff cell blocks one particular barrier, many other bypasses will allow flexible cells to flow through," Qin said in a statement.

Cancer stem cells are known to be squishier than other cancer cells. The team of scientists showed that flexible cells separated by the MS-Chip exhibited gene expression patterns consistent with cancer stem cells.

The analysis of separated cells showed the flexible cells were less likely to express cell cytoskeleton genes and more likely to express the motility genes that could contribute to metastasis.

By testing for the presence of metastatic cells, doctors may be able to tell whether cancer treatment was successful, or an as-yet untreated cancer's likelihood of metastasising to another part of the body.

Each MS-Chip costs about USD 10 to produce.

The details of the device were published in the journal Proceedings of the National Academy of Sciences.