Carol W. Greider is the Daniel Nathans Professor & Director of Molecular Biology & Genetics at Johns Hopkins University. Her research on telomerase (an enzyme she helped discover) and telomere function won her a 2009 Nobel Prize in Medicine. Prior to joining the Johns Hopkins faculty, she obtained a Ph.D. in Molecular Biology from the University of California, Berkeley, in 1997, and was a faculty member at the Cold Spring Harbor Laboratory. She is a member of the National Academy of Sciences and a recipient of the 1998 Gairdner Foundation International Award.
Question: Are we on the cusp of a genetics revolution?
Carol Greider: I think that we're in the middle of the age of genetics; I don't think that we're on the cusp of a revolution. I mean, I think with the sequencing of the human genome and now sequencing of many, many different genomes from a variety of organisms have given researchers such powerful tools to find out new associations. Being able to compare whole genome sequences from many, many different organisms, one can see what is conserved and therefore what is very important. So I think that the tools that we've been given just in the last 10 years are tremendous, and people are just now learning to be able to take advantage of those. And yes, there are of course ethical implications in terms of issues having to do with insurance and genetic privacy issues. If whole genomes are going to be sequenced, who will have that information? And I think that there are a lot of processes going on. There's a bill that was passed a number of years ago, the Genetic Information Privacy Act, which will limit the use that can be made of some of this. But I think it's an ongoing process that people need to be discussing more widely, that the more people in general in the population understand about genetics, the more they'll be able to have an informed discussion about these issues when they come up. So I think that scientific literacy is going to be really important as these things are disseminated more into the public in terms of the possibility of people having their own DNA sequenced, and what does it mean? And what does it mean to them, and what does it mean to family members who might not want to know that? Those are privacy issues. And the only way to move forward with that is to really have an informed discussion and to talk about it. So that's why I think that general education in terms of genetics is really essential.
Question: Are you worried or excited about the changes genetics research will bring?
Carol Greider: I'm excited about what's to come, but I think that along with the actual scientific changes there's a certain responsibility of scientists and educated people in general to talk about these things, because I think that with knowledge comes power. And so the more that the lay public understands about what we're learning in genetics, the more they can then understand how it would be useful to them. So I think it's a very, very exciting time, but I think that there's also a responsibility to be able to discuss things in a very open way that makes clear what the implications are and what the implications aren't.
Question: What will be the technical and ethical limits to genetic manipulation?
Carol Greider: It depends on what you mean by genetic manipulation, in the sense that we do genetic manipulation in the laboratory all the time to try and test ideas about how genes work. So we will take cells and we will change the genes in those cells and then be able to ask what is the consequence of that change. That's basically doing an experiment. We do that with mice as well. If we want to understand—for instance, we wanted to understand what would happen if a cancer cell didn't have telomerase. Could it still grow? So we generated a mouse, and the whole mouse doesn't have telomerase. So that's a genetic manipulation of the mice, but it was an important question to know the answer what would happen if you could completely get rid of telomerase. So I think that in that sense, those kinds of genetic manipulations are very powerful tools that scientists have. Now, if you're talking about things like human genetic engineering and those kinds of things, there are certainly ideas about gene therapy that people have put out there to solve various diseases, and some of the ones that people have been looking at are diseases that are in the blood, because blood cells are very accessible to changes. And those kinds of things don't worry me so much except for the technical aspects of—in some cases when you try and put genes back into cells, people have found that then those genes can cause other changes, which in some cases can lead to cancer. So there are clear technical hurdles which have to be overcome in that realm. And in terms of germline gene therapy, where you may change something permanently in the human germline, I think that basically that is something that's out of the question and shouldn't really be on the table. I don't think that anybody's really discussing changing the human genetic germline.
[Question: For technical or ethical reasons?]
Carol Greider: For ethical reasons. Technical as well, if we can't even get it right right now. If the science today—we can't do a bone marrow transplant; that is, take some bone marrow cells and correct a defect of a single gene in the blood, put that back in and know that the correction is going to happen. And instead, these children developed tumors because of unknown consequences in doing that. So if we can't even do this to blood cells, we are very, very far technically from being able to do anything without having many unintended consequences in the germline. So for technical reasons I would say it should be completely out of bounds, and then there are the ethical issues, which again would need to be discussed in a broader context. And I don't know of anyone that seriously thinks that that is something that one should be changing.
Recorded November 10th, 2009
Interviewed by Austin Allen