It has been proved that these large pachyderms have a tumor suppressor gene called P53. It can inhibit cell proliferation and give it enough time to repair its own damage. In addition, if cells can't be repaired, genes will prompt them to commit suicide, a process called cell self-destruction.
Another feature that distinguishes whales from other mammals is that they have many repetitive tumor suppressor genes, which can prevent the development and growth of cancer.
This shows that whales are unique among mammals. In order to evolve a huge body shape, these important housekeeping genes must keep up to keep the species healthy. These genes are evolutionarily conservative, but they can usually prevent cancer.
P53 gene inhibits cancer;
Since p53 was first reported in 1979, more than 20,000 related research papers can be found on Medline. At first, people thought that p53 gene was an oncogene, but with the deepening of research in recent ten years, the function of p53 as a tumor suppressor gene was gradually revealed. Mutation of p53 gene has been found in more than 50% of human tumor tissues, which is the most common genetic change in tumors, indicating that the change of p53 gene is probably the main pathogenic factor of human tumors.
After the mutation of p53 gene, due to the change of its spatial conformation, it lost its regulatory function on cell growth, apoptosis and DNA repair, and p53 gene changed from tumor suppressor gene to oncogene.
P53 protein is mainly distributed in the cytoplasm of nucleus, which can specifically bind to DNA, and its activity is regulated by post-translational modifications such as phosphorylation, acetylation, methylation and ubiquitination. The biological function of normal p53 is like "the guardian of genome". At the G 1 stage, DNA damage points were examined to monitor the integrity of the genome. In the case of injury, p53 protein prevents DNA replication, so as to provide enough time for DNA repair. If the repair fails, p53 protein will induce apoptosis. If both copies of p53 gene mutate, cell proliferation will be out of control, leading to cancer.
Refer to the above? Phoenix. Com- Why don't whales get cancer?
Refer to the above? Baidu Encyclopedia -p53 Gene