Subset of carbon nanotubes poses cancer risk similar to asbestos in mice

November 06, 2017

Nanotechnology, the science of developing materials containing very small fibers, is having a growing influence on daily life. Now researchers have shown for the first time in mice that long and thin nanomaterials called carbon nanotubes may have the same carcinogenic effect as asbestos: they can induce the formation of mesothelioma. The findings were observed in 10%-25% of the 32 animals included in the study, which has not yet been replicated in humans. The work appears November 6 in Current Biology.

Long carbon nanotubes are a subtype of nanotubes used in the manufacture of incredibly strong, yet lightweight, materials that are increasingly being used in a number of industrial and consumer products, including sports equipment such as helmets and bicycles, aircrafts and sports cars, and computer motherboards.

"Unlike previously reported short-term studies, this is the first time the effects of long and thin carbon nanotubes, leading to mesothelioma, have been monitored in mice over many months," says senior author Marion MacFarlane, a Professor at the Medical Research Council (MRC) Toxicology Unit in Leicester, UK.

"Importantly, not all nanofibers pose a hazard," she adds. "We want our research to inform manufacturers and regulators about safer options when a nanofiber is being selected for the production of nanomaterials for emerging technologies"

"The outcomes seen in this paper will thus help contribute to a 'Safe by Design' approach," says first author Tatyana Chernova, a senior staff scientist at MRC.

In the animal experiments, the investigators placed long carbon nanotubes in the pleura, the area around the lungs where mesothelioma develops in humans. "In that way, we followed changes in the pleura throughout disease development, observing stages of chronic inflammation, activation of pro-oncogenic signaling pathways, and eventually inactivation and/or loss of genes that are the gatekeepers of cancer development," MacFarlane says. The mesothelioma caused by long carbon nanotubes mice was in many ways similar to tumor samples from patients.

The investigators stress that the danger is posed only by types of nanomaterials that are long, thin, and biopersistent--meaning that they are not broken down inside the body: "these long, thin nanotubes are very similar to asbestos in their structural and physical characteristics," MacFarlane says. "The immune system does a good job of recognizing nanotubes that are shorter, thicker, or tangled up. They can be phagocytized by macrophages and cleared out of the body."

Another important set of findings came out of the work: the researchers learned new details about what happens during the very long latency of mesothelioma development and provided new information on the mechanism by which mesothelioma develops. Observations in the mice showed that chronic inflammation caused by long nanotubes led to inactivation of the same genes observed to be disrupted in people with mesothelioma. The researchers found that hypermethylation and silencing of the Cdkn2a locus ultimately led to loss of the tumor suppressor proteins p16 and p19.

"Because mesothelioma is diagnosed when it's quite advanced, we don't know much about the early mechanisms by which it forms," Chernova says. "This research could help us find biomarkers for early detection, as well as provide information for developing targeted therapies for this devastating disease."
This work was supported by the UK Medical Research Council and a British Lung Foundation Asbestos Project Grant Award.

Current Biology, Chernova et al. "Long-Fiber Carbon Nanotubes Replicate Asbestos-Induced Mesothelioma with Disruption of the Tumor Suppressor Gene Cdkn2a (Ink4a/Arf)"

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: To receive Cell Press media alerts, contact

Cell Press

Related Immune System Articles from Brightsurf:

How the immune system remembers viruses
For a person to acquire immunity to a disease, T cells must develop into memory cells after contact with the pathogen.

How does the immune system develop in the first days of life?
Researchers highlight the anti-inflammatory response taking place after birth and designed to shield the newborn from infection.

Memory training for the immune system
The immune system will memorize the pathogen after an infection and can therefore react promptly after reinfection with the same pathogen.

Immune system may have another job -- combatting depression
An inflammatory autoimmune response within the central nervous system similar to one linked to neurodegenerative diseases such as multiple sclerosis (MS) has also been found in the spinal fluid of healthy people, according to a new Yale-led study comparing immune system cells in the spinal fluid of MS patients and healthy subjects.

COVID-19: Immune system derails
Contrary to what has been generally assumed so far, a severe course of COVID-19 does not solely result in a strong immune reaction - rather, the immune response is caught in a continuous loop of activation and inhibition.

Immune cell steroids help tumours suppress the immune system, offering new drug targets
Tumours found to evade the immune system by telling immune cells to produce immunosuppressive steroids.

Immune system -- Knocked off balance
Instead of protecting us, the immune system can sometimes go awry, as in the case of autoimmune diseases and allergies.

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.

Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.

How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.

Read More: Immune System News and Immune System Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to