美国科学60秒-SSS 2015-06-23（在线收听）

 This is Scientific Americans 60 seconds science, I am , got a mimute? probiotics are so hot, bacterial that we can consume in food like yoghurt, miso and pickles can help us got my grow bands, they are happy and healthy.Now there might be another role for these probiotic bacterial: cancer detection.Two paper in Journal Science Translational Medcine explain how researchers hope to get bacterial to be diagnostic tools.Sangeeta N. Bhatia is liver expert and senior author of one of the papers. Her lab has been trying to figure out how to get nanoparticles to the liver that would sent signal detectable in urine and then counter the tumor.Cancers that start in the core of pancrease can metastasize to the liver witch can be deadly.One of the students in our team had idea that we could imagine there is material, the diagnostic material that would grow itself, and you wouldn't need very much of it to turn out a tumor and concern it safey ? . and we realize that bacterial are in many ways just such device.that they can natually home on tumors.So maybe we can hijack that ability of bacterial to home on tumors and self-amplify to creat a urine diagnostic.Bhatia's lab teamed up with a lab at the university of Califonia santiago with expertise in synthetic biology basically alter microbe to have specific functions.So we just going out to finding nature strains that would colonize tumors and do what we want it.We could , em, keep strains that have good homing and then in doubt them with kick dotties (?) that we were interested in. The two labs ? strain of E.coli Nissle that is already used to provide healthy people with digest issue.They programed two bacterials to express specific enzyme after occupied liver tumors.If the bacterial colonize the tumor in mice, the mice would produce urine that,thanks to the enzyme, would turn red. The system worked, the bacterial found to tumors in mice to have them and urine changed color indicating a presence of cancer.Cancer-free mice also ate engineered probiotics showed no negtive healthy effect later.The technic is at this stage just proof of concept that Bhatia is got a lot of promises. We are really excited about the idea that you can take synthetic biology someday into both diagnostics and also therapeutics.So in this particular case, the circuitry that we putted into bacterial gave off a diagnostic signal that could be detected remotely.You can also imagine that we are working on circuits they give off killer therapy that would kill the tumor directly and in making smart circuits that do that responsive ways.You can even imagine we have mixtures of bacterial that do both diagnose and therapy. So I think there is really a whole world of possibility is once you think about using bacterial as parts of engineered functions.