Many e-mail programs let you program them to recognize and delete unwanted messages or junk e-mail based on keywords found in the text or subject line, says Not Exactly Rocket Science's Ed Yong, and a Harvard researcher has found a way to apply that principle to cancer cells. Zhen Xie, who published his work in Science, developed a "genetic logic circuit" that prompts cells to self-destruct if it reads levels of five molecules within itself that signals the cell may become cancerous, Yong says. In other words, the cell reads itself and checks for certain key molecules in combination, much like the e-mail program looks for keywords, and if the program's parameters are satisfied, the cell kills itself. Xie worked with HeLa cells, a common line of cervical cancer cells widely used in cancer research, and identified five microRNAs that differentiate HeLa cells from healthy cells. Then, Yong says, Xie created five genetic switches that would only flip if these five microRNAs were found at sufficiently high levels within the cells. The switches control the Bax gene, which controls cell death. If the circuit is introduced into a cell that carries these five microRNAs and the switches are flipped, then voilà — instant self-destruction, Yong says. The idea is to cause the cells to kill themselves before they can become problematic. Xie plans to start testing his circuit in animal models, but there's a long way to go before the concept could be used to diagnose or treat human. However, Xie's study proves that the principle is possible to execute, Yong says, adding, "You can imagine a future where our cells are loaded with simple biological computers that monitor our health at a molecular level. It's a far-off future, but not an unreachable one."
The Auto-Destruct Sequence Has Been Initiated
Sep 03, 2011