The health risk of asbestos has been known for 50 years
Asbestos has been linked to the cause of cancer for almost 50 years. The exact reason for this connection has not yet been sufficiently understood. Swiss researchers have now found out why asbestos is so harmful to the body. According to the research results, the shape of the asbestos fibers is significantly involved in the harmful effects.
The fibers of the asbestos are long and pointed and can cause chronic inflammation. Study leader Emanuela Felley-Bosco reports that the body responds to these inflammations with a kind of wound healing that unbalances the immune system. As a result, emerging tumors would no longer be controlled enough. The results of the study were recently published in the specialist magazine "Oncogene".
Asbestos does not cause lung cancer
The research team consisted of scientists from the university hospitals of Zurich, Geneva and Toronto in Canada as well as the University of Freiburg and the Swiss Federal Institute of Technology in Zurich. The researchers disproved the prevailing opinion that asbestos can cause lung cancer. Instead, the asbestos fibers pass through the lungs into the mesothelium, a cell layer that surrounds all internal organs, the scientists explain. They then settle there.
The fibers remain in the body
The lymphatic system cannot remove the long and pointed fibers. These remain in the mesothelium, where they repeatedly injure the surrounding tissue. These chronic injuries can eventually lead to the formation of tumors. The scientists gained their findings from mice that were injected with asbestos fibers in the abdominal cavity, since there is also a layer of mesothelium in the abdomen.
Chemically speaking, asbestos is harmless
The researchers were able to show that chemically, asbestos is harmless. The numerous micro-injuries trigger the immune reactions, which can ultimately lead to cancer. The signaling substances that are activated for wound healing also promote cell division, which can promote the formation of tumors, the experts explain.
Emerging tumor cells are no longer fought
The researchers found mutations in the RNA and assume that these mutations help to prevent the resulting tumor cells from being combated consistently enough and eventually lead to cancer.
Comparisons in humans show similar results
According to the scientists, analyzes of corresponding gene databases show that in human tumors with a poor course of the disease, the enzyme that mutates the RNA is also present in large quantities.
Cancer caused by asbestos was a black box
"Until now, cancer caused by asbestos was a black box," explains Felley-Bosco in a press release from the Swiss National Science Foundation (SNSF), which co-financed the study. The results of her team are useful for recognizing the early signs of inflammation and developing a specific therapy for mesothelial cancer.
New therapeutic approaches
"Therapy against the inhibitors of the immune system is a promising approach," says Felley-Bosco. There are already similar therapeutic approaches against mesothelial cancer today. A clinical study on immunotherapy in the advanced stage of the disease is currently being carried out at five Swiss and ten other hospitals in Great Britain and Spain. According to Felley-Bosco, the discoveries could also be useful for understanding other cancers caused by chronic intestinal inflammation such as ulcerative colitis or Crohn's disease and infections with Helicobacter pylori. (vb)