Doctors use a variety of methods to detect lung cancer in a person. This usually consists of both invasive and non-invasive procedures, like a biopsy, a CT-scan, or a chest X-ray. If you want to step even further out of the box, some dogs are trained to ‘sniff out’ cancer in humans.
But you can’t exactly keep a cancer-sniffing dog in the lab at all times. It just isn’t practical, and the cancer dogs probably won’t like the confinement either.
However, that doesn’t mean there isn’t another alternative; something that’s cheaper in the long run, and perhaps even quicker too.
Ain’t no thang but a ‘worm-on-a-chip’.
With the help of a species of roundworm called C. elegans, scientists have developed a way to detect lung cancer at perhaps a much faster rate than currently existing methods. It turns out, the nematodes (which measure less than 1mm in length) are attracted to the smell of cancer cells.
Researchers confirmed this by dropping the worms onto the center of a chip, with one end containing healthy lung cells, and the other end housing lung cancer cells. After about an hour, they observed that more worms gravitated towards the cancer cell culture, owing to their ‘preference’ for the odor they emit.
The chip is made out of polydimethylsiloxane elastomer – a type of silicone – and contains two wells, one on either end. The center portion of the chip is where the tiny worms are placed.
The chip used to house and detect lung cancer. IMAGE: Nari Jang / EurekAlert!
“Lung cancer cells produce a different set of odor molecules than normal cells,” says Shin Sik Choi, one of the project’s principal investigators. “It’s well known that the soil-dwelling nematode, C. elegans, is attracted or repelled by certain odors, so we came up with an idea that the roundworm could be used to detect lung cancer.”
Based on the tests using the special silicone chip, the researchers estimated that the worms had a 70-percent accuracy in lung cancer detection. However, they’re hoping to increase the method’s accuracy and sensitivity by using worms that have already been exposed to cancer cell media, giving them ‘memories’ of cancer-specific odor molecules.
In other tests, the researchers managed to find the specific odor molecules that attract the nematodes, 2-ethyl-1-hexanol – which apparently has a floral scent.
“We don’t know why C. elegans are attracted to lung cancer tissues or 2-ethyl-1-hexanol, but we guess that the odors are similar to the scents from their favorite foods,” said Nari Jang, the other principal investigator involved in the project.
“We will collaborate with medical doctors to find out whether our methods can detect lung cancer in patients at an early stage,” said Choi. The team plans to conduct tests using additional substances, like breath, urine, and saliva samples.
The earlier cancer can be detected, the higher a person’s chances of being successfully treated, reiterates Jang.
The team also hopes to use the special test to detect other types of cancer, though this still requires a bit more research and development.