A recent article in Medical Express reminded readers that our DNA goes back many generations, yet it was possible for a genome archeologist to call upon ancient elements that are embedded in our DNA and cause them to activate an immune response that kills cancer cells.
A simplified Webster’s description of DNA is that it is a group of molecules responsible for transmitting genetic instructions from parents to their offspring.
Discoveries: the Old and the New
Dr. DeCarvalho, a senior scientist at the PM Cancer Center in Canada, discovered “viral mimicry”. His discovery creates cancer cells that behave like infected cells. These cells throw the body’s immune system into a defensive mode against the newly-created viral mimicry cancer cells.
Recently Dr. DeCarvalho and his associates located elements of ancient DNA buried in our genome. When these elements are reactivated, they cause an immune response.
The doctor and his team also identified a key enzyme (ADAR1) that the cancer cells rely on to survive by avoiding the body’s immune response.
The newly discovered enzyme, ADAR1, prevents cancer cells from sending signals to the immune system. When the immune cells are inhibited, the cancer cells react to the drug therapies that create the viral mimicry.
Because of Dr. DeCarvalho’s identifying ADAR1, we now understand why certain cancer cells can create a defense that protects them against the immune system. The doctor explained that his team of genome archeologists set a goal of identifying how these ‘DNA relics’ function. This brought them to the conclusion that if given the right conditions, they can be reactivated and stimulate the immune system.
Repetitive DNA (a/k/a repeats) have thus far been defined as consisting of multiple copies in the genome but not possessing a well-defined biological function. They have often been referred to as “junk”.
But now they are seen in a different light. Dr. DeCarvalho said he was pleased that his team has an opportunity to work with the repetitive DNA relics in their fight against cancer.
This research has been presented by trainees in Dr. DeCarvalho’s laboratory. It has been published online in the October 21, 2020 issue of Nature.