Evolution not just mutation drives development of cancer [news release]
Evolution not just mutation drives development of cancer
From the 21 July 2015 Clinicalnews.org news release
A paper published today in the Proceedings of the National Academy of Sciences argues against the commonly held “accumulation of mutations” model of oncogenesis in favor of a model that depends on evolutionary pressures acting on populations of cells. Basically, the paper states that the ecosystem of a healthy tissue landscape lets healthy cells outcompete ones with cancerous mutations; it is when the tissue ecosystem changes due to aging, smoking, or other stressors, that cells with cancerous mutations can suddenly find themselves the most fit, allowing their population to expand over generations of natural selection.
The answer that DeGregori and CU Cancer Center colleague Andrii Rozhok, PhD propose is that in addition to activating mutation, cancer may require age-associated changes to the tissue landscape in order for evolution to favor the survival and growth of cancer cells over the competition of healthy cells.
Consider the following two evolutionary scenarios: In a grassy lawn, the health of the lawn is the best defense against dandelions; and in the time of the dinosaurs, the environment selected for giant lizards until the meteor hit at which point the new context favored the evolution of new species better adapted to the changed environment, including larger mammals.
Let’s start with the lawn: “Healthy cells are optimized for the ecosystem of the healthy body. But when the tissue ecosystem changes, such as with aging or smoking, cancer-causing mutations are often very good at exploiting the conditions of a damaged tissue landscape,” DeGregori says. In this scenario, DeGregori’s suggestion to explore the development of interventions supporting the fitness of healthy tissues is like applying fertilizer to the lawn rather than herbicide to the weeds.
No comments yet.