Nature Reports: Did the induced pluripotent stem (iPS) cell breakthrough happen faster than you thought?

Landis: Yes.

Nature Reports: What do you think of the public response to this breakthrough?

Landis: It's kind of very sad. Instead of focusing on the scientific potential—what you can learn in terms of reprogramming and the epigenetics of the cells—people seem to have focused on “We don't need embryonic stem cells” or “Oh yes we do need embryonic stem cells”. It's as if the science has been consumed by the political argument.

Nature Reports: What still needs to be assessed with induced pluripotent stem cells?

Landis: There are a zillion questions. The assumption on the part of a large part of the public that this does away with the need for embryonic stem cells is premature.

I find it hard to believe that you'd get back to the same starting point that a pristine embryonic stem cell would represent. You don't know what the undifferentiated state actually is and you don't know how they [the cells] are going to respond to differentiation.

If you're taking a fibroblast that's obviously gone through several developmental stages to get to its differentiated state and then you're getting it to go back to its undifferentiated state, I would be surprised if it took the same pathway backwards.

[Regarding pluripotent stem cells as disease models] An interesting catch could be that the mutations that give rise to the disease could interfere with the ability to reprogram. Everyone has just assumed that they won't, but I don't think we have any data on that.

Nature Reports: How can researchers compare human iPS cells to embryonic stem cells?

Landis: Given that they've had the mouse embryonic stem cells and mouse iPS cells for some time and have not yet completed the epigenetic comparison, I think it will take a lot to do the human.

Nature Reports: But comparisons can't be funded for the newer human embryonic stem cell lines.

Landis: You would be constrained to the identified lines that are available for funding. Obviously it would be better to have more lines. Jamie Thomson[who led one of the groups making the reprogramming breakthrough and was the first to generate human embryonic stem cells] has pointed out that one of the major disadvantages of the limited number of lines is that they come from a pretty narrow genetic repertoire.

Nature Reports: Scientists have called for comparisons between iPS and hES cells, but there is some ambiguity about what kinds of these studies the NIH could fund. For example, can people use data or RNA or techniques from newer embryonic stem cell lines that aren't eligible for NIH funding?

Landis: That's kind of outside my paygrade, that kind of regulation. Apparently Harvard has a very good policy that's written up that outlines what Harvard feels are the appropriate safeguards to make sure that you don't violate the NIH policy.

Nature Reports: What's going to happen now in terms of what science is being done and who's doing it?

Landis: [The buzz makes it sound] like it's really easy and that anyone who's cultured cells should be able to make their own pluripotent stem cells. In talking to people on the phone, it sounds like it's much more complicated than that. Jamie Thompson said that it took him four years.

There will be new grant applications to take advantage of this scientific advance, whether or not they will be outstanding grant applications is unclear. Also, with the advance of SCNT [somatic cell nuclear transfer] in primates, I expect we'll get more grant applications based on that.

Since this is a new area, and not many investigators have the expertise to make pluripotent stem cell lines, the issue won't be that there are too many [grant applications] that are outstanding but that there won't be enough that are outstanding.

Nature Reports: How will grants be chosen?

Landis: One of the most contentious issues at NIH is how much money is assigned by what the review says is the scientific merit of the grant versus how much money is assigned based on programmatic considerations.

If 50 grants come in and none of them are deemed outstanding, the institutes can then say 'none of them make the payline, but this [research] is absolutely critical.'

Nature Reports: How do you feel about NIH's leadership role in global science?

Landis: Do we want therapeutic advances using human embryonic research to come out of Singapore, China, Britain? That's a piece of the tension that exists.

I don't think that the NIH can do anything except talk about the fact that the science does not support the President's policy and at the same time to implement the President's policy.