A defence protein that causes cancer
Cancer is caused by the growth of an abnormal cell which harbours DNA mutations, «copy errors» occurring during the DNA replication process. If these errors do take place quite regularly without having any damaging effect on the organism, some of them affect a specific part of the genome and cause the proliferation of the mutant cell, which then invades the organism. A few years ago, scientists have identified an important mutagen which lies in our own cells: APOBEC, an endogenous protein that usually functions as protecting agent against viral infection. Today, a team of Swiss and Russian scientists led by Sergey Nikolaev, geneticist at the University of Geneva (UNIGE), Switzerland, has deciphered how APOBEC takes advantage of a weakness in our DNA replication process to induce mutations in our genome.