Genetic mutations in cancer cells can lead to treatment resistance, which could result in relapse, yet according to a new study in the journal PLoS Biology, it is possible that the reverse could also happen.
Steven Frank from the University of California, Irvine, and Marsha Rosner from the University of Chicago suggest that it could often happen that a few cells develop resistance before any genetic change occurs and that these cells later acquire the genes that stabilize this resistance.
The reason as to why it matters whether resistance comes before genetic mutations, or vice versa, is because a treatment’s efficacy first and foremost depends on prevention.
At present, scientists base their views on the belief that genetic mutations occur first and then spread to cause resistance, which is why treatment protocols have to base their focus on preventing the origination of cancer cells with its corresponding mutations that cause the resistance. In order to limit the likelihood of a cancer developing the mutations required to build a resistance, clinicians often use specifically designed combination therapies.
Frank and Rosner state, however, that a few cells may frequently become resistant prior to developing specific genetic mutations. It has been widely observed amongst identical cells that non-genetic resistance like this could occur through random changes in cellular characteristics, or, that it could occur when cells alter or reprogram their characteristics in response to various stress situations, like moving into new tissues or fighting toxic drugs.
Scientists know that cells have numerous flexible programs of expression in response to changes within their environment, for instance, if a cell first develops a resistance either by non-genetic randomness or flexibility, those resistant cells can subsequently acquire genetic changes to stabilize their resistance. A progression like this that starts with non-genetic resistance has to prompt scientists into rethinking their approaches of how to design combination drugs that are targeted at preventing relapse.
Even though the concept that non-genetic resistance comes first is not entirely new, scientists have still not altered their point of view due to the small amount of existing evidence. By combining evidence of previous studies together with a clear understanding of the evolutionary theory whereby populations adapt to extreme challenges, Frank and Rosner aim to open this perspective to a larger group of scientists. New studies that have been designed based on how evolution might occur in cancers, will demonstrate whether outcomes can be improved through using alternative treatment approaches.
Written By Petra Rattue