Blind diggers are not protected from cancer in the same way as naked ones
The two types of navvies have two different mechanisms of anti-cancer protection
LifeSciencesToday based on University of Rochester: Researchers Discover How Underground Rodent Wards Off CancerBiologists from the University of Rochester have found out how a blind digger fights cancer.
The mechanism they established differs from what was discovered three years ago in another long–lived and cancer-resistant species of blind - a naked digger.
A group of researchers led by Vera Gorbunova, PhD, Professor of Biology and Associate Professor of Oncology, and Associate Professor Andrey Seluanov, PhD, found that abnormally growing cells in a blind digger secrete interferon beta protein, causing their rapid death. Scientists hope that eventually this discovery will help in the development of new cancer treatments. The results of the study are published in the Proceedings of the National Academy of Sciences (Gorbunova et al., Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism).
Blind diggers (Spalax judaei and S.golani – VM) and naked diggers (Heterocephalus glaber – VM) – rodents with a long lifespan leading an underground lifestyle are the only mammals that never develop cancer. Three years ago, Seluyanov and Gorbunova revealed the mechanism of fighting cancer in a naked digger. Their study showed that a specific gene – p16 – makes the cancer cells of these animals hypersensitive to too much cell density and stops their proliferation in response to this signal – the so-called phenomenon of contact inhibition.
"We expected to find in a blind digger a similar mechanism for stopping the spread of cancer cells," says Dr. Seluyanov. "But instead they found out that he had developed his own."
In the picture taken by Andrey Seluyanov, there is a carrot at the bottom, and at the top there is one of the types of blind people – VMThe scientists made their discovery on the culture of fibroblasts of a blind digger.
After about 15-20 divisions, all culture cells underwent massive necrotic death within 3 days. This phenomenon of necrotic cell death did not depend on the conditions of cultivation and shortening of telomeres. The researchers found that the cause of rapid cell death is that the cells determine their condition as precancerous and begin to secrete a suicide protein – interferon beta. Suppression of the activity of p53 and Rb proteins completely saved cells from necrosis.
According to scientists, these results suggest that the resistance of blind diggers to cancer is due to a massive necrotic response to excessive proliferation mediated by the molecular pathways p53 and Rb and initiated by interferon beta. The death of precancerous cells is the result of the implementation of the same mechanism that kills both abnormal cells and their immediate neighbors and thus produces a complete "cleansing of the territory".
"Not only cancer cells die, but also neighboring cells, which may also be predisposed to the formation of tumors," explains Dr. Seluyanov.
"Although such a mechanism for destroying cancer cells is not used in the human body, we could fight some types of cancer and prolong the life of patients if we learned how to stimulate a similar "purification" reaction in human cancer cells," Professor Gorbunova believes.
In the near future, the researchers plan to establish the exact mechanism of activation of interferon beta synthesis in the cancer cells of the blind digger that have begun to actively proliferate.
According to Professor Gorbunova, this anti-cancer mechanism is the result of the adaptation of animals to life underground.
"Blind diggers spend their lives in underground burrows, protected from predators," she explains. "Living in such an environment, from an evolutionary point of view, they may have been able to afford a longer life expectancy, which implies the development of effective anti-cancer protection."
Portal "Eternal youth" http://vechnayamolodost.ru07.11.2012