Scientists turn mammalian cells into complex biocomputers
Computer hardware is getting a softer side. A research team has come up with a way of genetically engineering the DNA of mammalian cells to carry out complex computations, in effect turning the cells into biocomputers. The group hasn’t put those modified cells to work in useful ways yet, but down the road researchers hope the new programming techniques will help improve everything from cancer therapy to on-demand tissues that can replace worn-out body parts.
Engineering cells to function like minicomputers isn’t new. As part of the growing field of synthetic biology, research teams around the globe have been manipulating DNA for years to make cells perform simple actions like lighting up when oxygen levels drop. To date, most such experiments have been done in Escherichia coli and other bacteria, because their genes are relatively easy to manipulate. Researchers have also managed to link multiple genetic circuits together within a single cell to carry out more complex calculations in bacteria.
Scientists have tried to extend this to mammalian cells to create genetic circuitry that can help detect and treat human diseases. But efforts to construct large-scale genetic circuits in mammalian cells have largely failed: For complex circuits to work, the individual components—the turning on and off of different genes—must happen consistently. The most common way to turn a gene on or off is by using proteins called transcription factors that bind to and regulate the expression of a specific gene. The problem is these transcription factors “all behave slightly differently,” says Wilson Wong, a synthetic biologist at Boston University.