The secret to helping Greenland shark 400 years without cancer

Greenland shark (A dream of Microcephalus) is a slow -moving species in the deep sea, which can be more than 6 m longer and weighs more than one ton. People only know very little about the lives of Greenland sharks because they live in dark and cold waters. Scientists think that they are genital mature when they are 150 years old and an estimated life expectancy of about 400 years. This turns them into the most spectacular vertebra on the planet.

In order to clarify the reason they have lived for a long time but rarely develop tumors, Shigeharu Kinoshita from Tokyo University, Japan, and colleagues in the genetic sequence of a Greenland shark, discover the genes in each chromosome. They estimate that the genome was 86.5% and so far discovered about 37,000 genes, New Scientist On 4/3 reported.

The team found that the number of gene copies related to the activation of the NF-κB signal path of the Greenland shark is higher than other species such as whale sharks (Rhincodon typus), life expectancy is about 54 years, or white bamboo shark (Chiloscyllium plagiosum), life expectancy is about 25 years.

This road is used when the body’s immune system reacts with threats and participates in processes such as inflammation and tumor growth. The NF-κB disruption will cause the tumor cell to grow continuously and create conditions for pathogens to avoid the immune system attacks.

“Because of the immune reaction, inflammation and the formation of tumors significantly affect the aging process and longevity, the increase in genes involved in NF-κB signals may be related to the long life of the Greenland shark,” Kinoshita said.

The new research contributes to explaining why some sharks are less cancer than the prediction based on the large body size, according to researcher Aaron MacCneil at the University of Dalhousie, Canada. Scientists at College London, England, recently discovered that large animals are at higher risk of cancer, but also evolved to better defend against the disease. In addition, a large number of genes related to NF-κB signals has also been discovered in red sea urchins (Mesocentrotus franciscanus), species can live for more than 100 years.