Infectious tumour cells

摘要

Cancer cells are generally viewed as a problem innate to their host, but evidence is mounting that they can evolve to become infectious agents and be transmitted between individuals. The current view of cancel development is that normal cells are transformed into tumour cells by sequential mutations that activate cancerpromoting bncogenes', or inhibit genes that would otherwise suppress tumours, or trigger genetic instabilities. As a consequence, every tumour is the result of a unique evolutionary process as the cancer cells adapt to out-compete their neighbours. This process begins in its individual host and ends with the elimination of the tumour or the death of the host. Two studies, however, suggest that some tumour cells can behave like infectious agents and move from one host to another.