Turning the spotlight on breast cancer cells

Scientists are using the latest in nano-flare technology to detect breast cancer cells early on. The technology has been developed by Drs Chad Mirkin and C Shad Thaxton of Northwestern University, whose research was presented at the 247th National Meeting & Exposition of the American Chemical Society (ACS).

Sometimes, by the time a patient notices symptoms of cancer and visits a doctor, the first tumour has undergone metastasis - spreading from its original location in the body to another. This causes it to become even more deadly and, because it moves with stealth, it can go undetected for months or years.

“Therefore, the ability to detect metastatic cancer cells from patient blood samples, before the development of secondary tumours, would represent a revolutionary advance in cancer diagnostics,” the researchers said.

To catch breast cancer earlier, the researchers built upon Dr Mirkin’s invention of spherical nucleic acids (SNAs) - structures usually made out of a gold nanoparticle core covered with densely packed, short strands of DNA.

“We thought that if we could get large amounts of nucleic acids to go inside cells, we could manipulate and measure things inside cells,” said Dr Mirkin. “Most people said we were wasting our time, but then, out of curiosity, we put these particles in cell culture. Not only did we find that they go in; they went in better than any material known to man.”

Dr Mirkin’s group set out to turn the SNAs into a diagnostic tool called the nano-flare. He and Dr Thaxton designed nanoparticles which enter circulating healthy and unhealthy cells in blood samples and light up inside breast cancer cells, responding to metastatic markers.

“Nano-flares can detect just a few cancer cells in a sea of healthy cells,” Dr Mirkin said. “That’s important because when cancer spreads, only a few cells may break off from the original tumour and go into the bloodstream. An added bonus of these particles is that scientists may be able to sample the live cancerous cells and figure out what therapies they might respond to.”

Dr Mirkin added that nano-flares “represent the only way to measure genetic content in live cells” - thus, they could be used by scientists to see how drugs target different genes and help them develop better treatments. Life science company Millipore has already commercialised the particles for use in research labs under the name SmartFlares and offers more than 1200 variations.

The researchers have successfully tested the nano-flares’ ability to identify metastatic breast cancer cells in animal blood samples and are currently experimenting with human samples. “If the work pans out,” Dr Thaxton said, “a commercial diagnostic test could be available in the near future.”