Hi, I'm Judy Cole, the
Executive Vice President
and CEO of the MIT
Alumni Association,
and I'm delighted to welcome
you to this web production
of the MIT Alumni Association.
Welcome to the MIT Faculty
Forum, Alumni Edition.
I am Ann Gibbons.
I'm a writer for
Science magazine,
and I was a Knight
Science Journalism Fellow.
This is an interactive forum
so we encourage your questions.
Use the Google form
below the live video
feed to ask a question
or you can tweet one
to MITBetterWorld.
We'll get to as many
questions as we can.
So this month's
topic is CRISPR--
the CRISPR revolution, or
advances in gene editing.
So biologists continue
to hone their tools
for deleting, replacing,
or otherwise editing DNA,
and they're using
a strategy called
CRISPR that has become one
of the most popular ways
to do genomic engineering.
By using a molecular method
that bacteria usually
use to fight off viruses, by
snipping some of their DNA,
researchers have been able to
adapt this so-called CRISPR
system to edit genes
in many species,
ranging from yeast and
bacteria to fruit flies
and even, in two
cases, human embryos.
The unprecedented
control over genes
has allowed many new
types of experiments,
but also obviously
raised questions
about what CRISPR can enable
and the ethical issues
that come with that.
At least one group has already
used CRISPR on human embryos,
sparking calls for a
moratorium on similar work
and an international summit
at the end of last year
to discuss the science and
ethics of human gene editing.
Meanwhile, CRISPR is
making it much easier
to generate genetically
modified animals and plants,
creating new regulatory issues
that scientists, agencies,
politicians, and ultimately
society must address.
So last night, just for the
fun of it, I googled CRISPR,
and here's what I read.
These are headlines just
posted in the last 24 hours.
One was, "First Human
Test of CRISPR Proposed."
That was in MIT Tech Review.
The second was, "Gene Editing--
CRISPR Blocks Cancer Growth."
That was in Nature.
Another was, "Virus Hacks
Host Genome, Steals CRISPR
to Protect Itself."
So today, our alumni panel
will help us separate myth
from reality, share their
current research with us,
and perhaps untangle some of
the hysteria around the latest
headlines.
Panelists, let's have you
introduce yourselves and give
us an overview of
your current research
on the state of gene
editing in 2016.
And we're going to start with
Melissa Harrison who will also
give us a brief
definition of CRISPR.
So let's start with Melissa
Harrison introducing herself,
and then we will go to our
other two panelists who are
James Dahlman and Keith Tyo.
Hi, everyone.
So I'm in the Department
of Biomolecular Chemistry
at the University of
Wisconsin, and I'll just
give some brief visuals to go
along with my introduction.
So essentially, what my lab is
interested in is how you can
take two specialized
cell types--
in this case a
sperm and an egg--
and unite them to
create a new organism.
And ultimately what happens
when these two cell types come
together is they
make a single cell,
and this single cell now has
to divide and differentiate
into all of the cells
of an adult organism.
And so the DNA in
this single cell
and in all the cells of
the adult are the same.
So we're really interested in
how is this DNA, this genome,
interpreted to
drive development.
And because there are so
many shared properties
amongst all organisms, we
do our studies in the fruit
fly Drosophila melanogaster.
And CRISPR-mediated
genome editing
has been incredibly
influential for us
to allow us to introduce
specific mutations
into the Drosophila backbone.
So high-throughput sequencing
has identified numerous DNA
sequences that are associated
with diseases such as cancer,
but it's really
essential to determine
whether those changes
in the DNA are actually
causing the disease.
And so what CRISPR has
allowed people to do
is to make those
exact mutations that
are associated with disease
in any organism that's
a good model and to test
what the effects are
of that mutation.
So CRISPR has become really
facile and quite easy,
and so these are a
number of organisms
that people have already
modified using the CRISPR-Cas9
system.
So that's, for me, why
it's such a useful system,
but just briefly, what is so
novel and how does it work?
So it's important
to keep in mind
that what really the
CRISPR system is doing
is creating a double-strand
break in the DNA,
and that's really
all that it's doing.
It's the cell's job to repair
that DNA and the researcher's
job to control how that
DNA is being repaired.
Previously, there
were TALE nucleases
and Zinc-finger nucleases that
could cut double-stranded DNA
and make this
break, but what was
revolutionary about the CRISPR
system was how easy it was
to generate these
breaks in a much more
targeted and specific manner.
So where the researcher steps
in is both the introduction
of the programming
of this Cas9 protein
but also researcher-directed
strategies
to influence the cellular
repair machinery.
So briefly, what are
the basic components
of CRISPR-mediated gene editing?
One is the Cas9 protein--
this is the nuclease
that cuts the DNA--
and the other is
a small guide RNA
that easily programs
this protein
where to go in the
genome and how to cut it.
And then if wanted,
the researcher
can provide a
template for repair.
And so a real brief
example from our lab
is that we wanted to look at
where a protein is in the cell,
and so we can add a
fluorescent tag to that protein
by changing the [? gene ?] DNA.
So here's, say,
the original gene.
What did we do?
We programmed that Cas9 to
make a double-stranded break,
and we gave it a repair template
that had that fluorescent tag.
Then we could
screen and identify
flies that had this
modified genome,
and we could now
visualize this protein
in the nucleus of a developing
organism and see where it went.
And so I just want
to be very clear
that this was all part of an
ongoing collaboration with two
other members of the
UW Madison community--
Jill Wildonger in
Chemistry and Kate
O'Connor-Giles in Genetics.
And we have a website for
anyone who's interested,
and then also this is
my website if people
are more interested in
my work So with that, I
need to get out
of screen sharing.
So let's go to James.
Could you introduce
yourself and tell us
how you're using CRISPR?
Sure.
So hi, everybody.
My name is James Dahlman.
I'm a recently-appointed
assistant professor
in the Department of Biomedical
Engineering at Georgia Tech,
and we use CRISPR a
few different ways.
So my background is
actually in drug delivery
and nanoparticle design.
So we do a lot of
targeted drug delivery
of CRISPR therapeutics.
But I also have some background
in actually engineering
and designing the
CRISPR system itself,
and I did this as
post-doctoral fellow
while I was at the
Broad Institute studying
with Feng Zhang.
And there, we learned a pretty
important concept which is--
well, I guess we're not
the ones that learned it,
but it's an important
concept to point out.
It's this idea that
the CRISPR-Cas9 system,
as Melissa said so well, is
a really effective and useful
system.
And one point I'd
really like to highlight
is that when you think about
the system from an engineering
perspective, it's a
really nice system
to work with because you can
engineer both the protein
itself--
so you can actually
engineer that Cas9 protein
to do other stuff
that you want to do.
You can have it turn on a gene
instead of turning off a gene.
You can make it cut one strand
of DNA but not the other.
You can make it cut
no strands of DNA.
So you can actually
engineer the Cas9 protein
to do other things.
But that's not all, actually.
A second really big concept
and one of the reasons
why this technology
has been so useful
is we can also engineer
the guide RNA itself.
And so to give you a
brief example of this,
we were able to publish
a paper last year where
we showed that by changing
the structure and the size
of the guide RNA,
we could actually
have it target the
correct genomic DNA,
but not cut the DNA and
instead actually turn
on gene expression with a Cas9
protein that normally deletes
the gene.
And so if you think about
this, what we're able to do
is use this special,
designed RNA to upregulate
gene A in a cell and then
put in a regular guide RNA
to cut gene B in a cell.
And so we called it
orthogonal gene editing, which
colloquially can
be viewed as this.
So in the same cell we can turn
off gene A and turn on gene B
at the same time, and
this is done by basically
engineering the RNA.
Like I said, we'll talk
about this a little later,
but I'm interested in the
therapeutics and translation
of different genetic
therapies, including CRISPR.
But the real take-home point
is if you guys are engineers
listening, this is a
really engineerable system,
and there are
many, many examples
of engineering both the
protein as well as the guide
RNA to do different things.
That's great.
Let's go to Keith.
Could you please introduce
yourself and tell us
how you're interested
in or using CRISPR?
Sure.
My name's Keith Tyo.
I'm an assistant professor
at Northwestern University.
I'm in the Department of
Chemical and Biological
Engineering.
Let's see.
I have some slides
I'd love to share,
if I can remember
the process here.
Let's see.
OK, you guys can see that?
Yes.
So I'm interested in
engineering microbes, so
things like E. coli and things
like yeast that really take
advantage of many of the things
that biology does really,
really well and trying
to convert those
into something that's
generally useful for society.
And so those two things
as a chemical engineer
I'm really interested
in are catalysis,
which if you think broadly is
the exquisite chemistry that
happens inside a cell where
you take something like a sugar
and you make these
extremely complex polymers
and other types of
molecular structures.
It's really amazing,
and so harnessing
that is a big interest of mine.
And the second thing that nature
does very well is sensing,
and so whether that's
running from something
or running toward
something, we've
all evolved very
sophisticated ways
of detecting our environment.
So that's something else
that I'm interested in--
co-opting some of
these natural processes
to do something
useful for society.
So I look at that in a
couple different ways.
So as chemical
engineers, we'd like
to be able to synthesize
chemicals that we couldn't
make otherwise.
So some of these
are drug compounds
that are inefficient
to be synthesized
by traditional organic
synthesis routes, biofuels,
other high-value chemicals
that require a lot of land
if we were to grow crops
that make that chemical,
but we could make it very, very
efficiently in a bioreactor.
So an example there
would be essential oils.
It takes a ton of plant
to make a small amount
of essential oil.
On the other side of things,
we think about yeast sensors,
and this is really--
we'll skip to that slide--
is how do we take
yeast and make it
into something that
might be useful
as a health care diagnostic.
And so yeast are very good
at sensing their environment
because you can make
them dry active.
Then they're cheap
and transportable.
So in developing countries, this
could be a very valuable way
to diagnose diseases in places
where there may not be reliable
electricity or the
type of hospital
we enjoy in the United States.
And so at the end
of the day, you
can imagine something that
looks like a pregnancy test,
but that strip is
now a yeast cell.
And it makes things interesting.
And then finally, this
is just emphasizing
that idea of novel reactions
that we can carry out.
So pyrazinamide in
the top half of this
is a tuberculosis
drug that's currently
made by chemical synthesis,
and what I'm showing here
is a reaction
diagram where we use
enzymes in nontraditional
ways to get to those products.
And so where CRISPR has really
enabled what I do is based
on this
design-build-test-learn cycle,
which is what we follow
in synthetic biology.
And so if you think
of design and learn
being the computational
aspects of understanding
complex systems, the build is
trying to put together genes
from different
organisms, modify genes
in that yeast or E. coli cell
that we're trying to work in.
And I have there
in 2010-- that was
when I was doing my post-doc,
but even a year and a half
ago in my lab, depending
on the type of modification
we'd want to make, that
could be up to one per month
as the slow rate that
that would happen.
And basically, now, four per
week is very, very doable,
and if we get more
creative, we can actually
be even faster than that.
But as you can imagine what that
allows us to do is learn much
faster because this what used
to be a rate-limiting step
in our ability to
understand these systems--
now because CRISPR is so
simple and facile to use,
that build step has extremely
compressed in terms of time,
and so we can now go
through this cycle
really at a once per
week type of rate.
Very interesting.
OK, so I'm going to start
taking some questions.
Can you guys hear me OK?
And I'm going to
start with James,
but first I want him
to explain one thing.
When you were talking about
working with gene regulation
and engineering
these Cas9 proteins,
what organisms are
you working in?
What's your model organism?
And then after you answer
that, I want you to take
[? Adlai's ?] question
from Cambridge,
and here's his question.
"Have you had success with
delivering gene editing tools--
CRISPR and some others--
beyond the blood-brain barrier
for targeting certain neuron
types or aberrant genes?"
Great.
Number one, that's
a great question,
and I'll get to that in
a second as suggested.
So to address the
first question, which
again is which model
organisms are commonly used,
this answer is probably
variable from lab to lab.
But I know that in many
laboratories that I'm
familiar with, we
perform a lot of editing
experiments in human cells.
So we don't really
have an organism.
It's just a cell at that point.
But you can also
perform editing in mice.
I've heard rumors of people
doing it in larger animals
as well--
non-human larger animals.
I remember reading something
at some point a few months ago
saying that basically every
model organism that this
has been tried in so
far, it's been successful
or something like that.
I don't know if that's
100% of the cases or not,
but I've heard of work going
on in C. elegans, certainly
in bacteria, in mice,
in rats, and as we
heard just a few minutes
ago, also in flies as well.
So we can use a lot of
different model organisms,
and one of the--
I'll just say something
quickly related to that--
one of the things that's kind
of interesting and perhaps
unexpected is keep in
mind that this system,
this CRISPR system, is a
system that we've basically
hijacked from bacteria.
So this system wasn't
really designed,
if you think about
it, to work in mice,
but the system is so
robust, even though it
was evolved in bacteria,
that we can basically
take it out of bacteria
and try it in all
these different organisms.
And so it's a really powerful
system, and that's not a given.
I just want to make that point.
Now, moving on to the
second question related
to the delivery specifically
across the blood-brain barrier,
as far as I'm aware, that has
not been done systemically.
But we also have to keep in
mind that with the brain,
there are other ways
to access the brain.
So when we think about
delivering a drug to the brain,
there are a few
different avenues
where you can inject the drug.
So as a example,
you can take a pill
and try to get something
into the brain that way.
You can inject it basically
through the equivalent of an IV
bag straight into
the bloodstream.
But with the brain, you can
also try to inject it directly
into the brain by performing
a little microsurgery,
and that has been
done, actually.
People have done that
little microsurgery directly
in the brain.
But if you're
asking about what we
call systemic delivery, which
is drug delivery where you're
trying to basically
inject it into a vein
and get it to go to the brain,
or the heart, or the lung,
or really anywhere you want to
target it after injecting it
into the brain,
as far as I know,
that delivery has still
been extremely challenging.
If people are interested,
we can talk a little bit
later about why that's the
case, but the short version
is that delivering
CRISPR-Cas9 therapeutically
has been a huge challenge.
And it will probably remain a
huge challenge and therefore
a big focus of research
for several years.
So to repeat back and to
state the big bullet points,
we use it in a lot of different
model organisms, number one.
Number two, when we
think about the brain,
people have performed
gene editing
by spraying stuff
locally into the brain
after performing
a little surgery,
but people have not successfully
delivered CRISPR-Cas9
systemically by
injecting it into a vein
or putting it into a pill.
And actually, people haven't
done that for other organs
as well.
It's been very hard to get
systemic direct delivery
for other organs.
Can you say, James, why
it has been so hard to get
systemic CRISPR-Cas9 drugs?
What is going on there?
Is it a regulatory issue?
And technically, how is it hard?
How close are people to
developing any kinds of drugs
or therapeutics?
Yes, that's a great question.
And the reason why
it's been difficult
is because the system is a
complicated system from a drug
delivery standpoint.
So I will give you an example.
When you want to
deliver a regular drug--
let's say you want to
deliver a cisplatin,
which is a chemotherapeutic,
or you want to deliver
what's called an siRNA,
which is a very small,
naturally occurring RNA--
that drug delivery is
already hard enough.
So if you want to deliver
the chemotherapeutic,
you have to inject the drug.
It has to avoid getting cleared
by the kidney, by the liver,
by the immune system.
It has to get to
the right tissue.
It has to get into
the right cell.
It has to get into the
endosome of the cell,
out into the
cytoplasm of the cell.
All of these steps, even
with a very simple drug
like a chemotherapeutic, which
is just one simple molecule,
is really hard.
Now, you look at CRISPR-Cas9.
You have all of
those hurdles still,
but in addition
to those hurdles,
you also have the fact
that the system requires
both a protein and an RNA.
The protein and the RNA
have to come together,
and then the
protein and RNA have
to get into the
nucleus for it to work.
And so those
additional steps make
it really, really inefficient.
So it's a complicated
system biologically,
and because drug
delivery is already
hard with simple
molecules, drug delivery
gets really, really hard
when it's a complex molecule
like CRISPR-Cas9.
We have a question that
comes from Mount Holyoke,
and that is a question
from Al in Mount Holyoke.
"How much of your
work is coding"--
and I imagine that
means modeling--
"versus how much of your work
is in the lab in Petri dishes
versus wet lab kind of work?"
So Keith, maybe you
can take that question.
I'd be happy to.
As I was alluding to in that
circular diagram, the left half
of that was basically coding,
computational analysis,
and in the past, the amount
of data that we could generate
was relatively small.
So the amount of analysis we
could do was accordingly small.
What CRISPR has really done
is by greatly increasing
the number of hypotheses
that we can test,
it allows us to generate
much, much more data.
And so increasingly
now, computation
is a very large
part of what we do.
40% of my lab, so four
of 10 graduate students,
are 100% computational
and are really
just trying to take the
really amazing data that we're
getting now and trying
to answer larger, more
systemic questions that would
just have been impossible
a short time ago.
So I have my own
question for Melissa.
When you talk about using
CRISPR-Cas9 to study
development, what is
most exciting for you
right now in using this
system to study development,
either in your
lab or other labs?
What do you see is
the potential there
and what is underway
that is particularly
promising or exciting for you?
I mean, the possibilities
are endless,
and I can't limit it to one.
So one of the things that's
really interesting to us
is that--
what I alluded to--
there are these mutations which
are associated with disease.
So cancer genomics has
really made a huge impact
in sequencing large
numbers of cancers
and finding mutations that
are associated with them.
We're really understanding
what those mutations
do and whether or
not they're causative
for any certain disease.
And so now what we can
do is actually make
that exact mutation
in an organism,
and for most organisms,
homologous recombination
hadn't been facile enough.
Even in Drosophila it
was incredibly hard.
And so the fact that we can now
go through and within a matter
of a month make a specific
disease-causing mutation
in a fly and use
that as a model,
or in other organisms-- mice,
axolotl, swine, whatever.
So that's one really
exciting thing,
and then the other is
the fact that we can now
label proteins in vivo in
their endogenous studying
and study what they're doing.
So with the
fluorescently-tagged version,
we're actually watching
it over cell divisions
and seeing where
that protein goes
and seeing where it
moves over development
and what cells it's
being expressed in.
So really, for us, it's
an amazingly powerful tool
to probe at the genome
level what is going on.
And what are you seeing as
far as that protein over time?
What is particularly
interesting about the system
you're looking at?
So this protein actually
reprograms the embryonic genome
to totipotency in
Drosophila, and we
think similar things are
happening in mammalian cells.
And so what we can
see with this protein
is that it basically behaves in
ways that we might or might not
expect and predict
based on its dynamics.
So we have another
question here.
This is for James now.
Jose in San Francisco wants
to know, "where do you
see these kinds of therapeutics
10 years from now--
over-the-counter deliverables?"
Can you answer that, James?
Sure.
So Jose, thank you very
much for the question.
It's another great question.
So I'll answer the second
part of your question
first directly.
I have to be honest.
I don't think it's likely
that in 10 years we'll have
over-the-counter versions
of these things simply
because the implications of
these gene-editing therapeutics
are really--
they're serious implications.
And when you're going in
and making permanent changes
to DNA, that's a
pretty serious thing.
And so development
of therapeutics
is going to be a little bit
more specialized, I think.
And I can give you a few
examples of a few therapeutics
that may be reasonable
within, let's say, a decade,
and this is--
please don't ever
quote me on this
because developing a drug
takes a really long time.
So actually instead of
saying 10 years, all I'll say
is I'll describe some
therapeutics that
are likely to perhaps
come out first,
instead of putting
a timeline on it.
One of those
therapeutics might be
something related to the eye.
So as we talked
about a minute ago,
delivery is a
really big problem.
And so if you think
about the eye,
you can literally take a
drug, put it into a needle,
and inject it
directly in your eye.
Many drugs are actually
administered that way now.
And so there are going to
be CRISPR-based therapeutics
that people will
try to advance where
you try to go in and edit,
or delete, or manipulate
genes that cause, for instance,
a progressive blindness that's
a genetic form of blindness.
One other type of
therapeutic that
may be in the foreseeable
future is again
related to an easy
delivery problem, which
is disorders of the blood.
So in this case, what you can
do is basically take somebody's
blood out, and take the
cells from the blood,
and actually edit them
in a Petri dish in a lab,
and then change them the way
you would like using CRISPR,
and then put them
back into the person.
And so again,
you're circumventing
that systemic drug
delivery problem.
And although that might seem
far-fetched or like science
fiction, it's
actually not the case.
There are actually
therapeutics that people are
thinking about for HIV/AIDS.
There are people that
are thinking about them
for what's called
immuno-oncology
and in other types of
immunological diseases
that are really perhaps
changeable when you trying
to target cells in the blood.
So the eye and the
blood I think may
be in the foreseeable future.
But just to throw
a bit of optimism
in there, as a
scientist, in a long time
the pipe dream begins--
this is still a pipe dream.
But the pipe dream is to have
a one-shot injection that's
curative for, let's
say, hemophilia
or for some other genetic
disease that we understand,
like Huntington's
or cystic fibrosis.
Now, there are going
to be a ton of hurdles
that need to be overcome,
and it might not ever happen.
However, that's the pipe
dream and the potential
of this technology if we use it
and develop it the right way.
I can also imagine
that the challenge will
be how do you get a
high enough dose for it
to really work systematically?
How do you harness the immune
system to work with it?
I guess these are all
the kinds of problems
you're working on in cell lines
at this point and in modeling.
Is that right?
And then we'll go to another
question after that, James,
but I just wanted
[? interject ?] that question.
Yes, that's a great
follow up, and yes, that
is in fact correct.
And in addition to that,
there are other hurdles like--
again, not to harp on delivery
too much, but it's pretty,
I guess, easy to
understand and agreeable.
We can all agree on
this, that if we're
going in and delivering a drug
that's going to actually edit
the genome and we
want to do that
in the heart for
some heart disease,
we don't want that
going everywhere.
We want to try to limit that
and deliver it to the heart
more so than the kidney,
or spleen, or liver,
or wherever else you
don't want it going.
And so there are all
of these hurdles that
need to be overcome, including
the ones you just mentioned,
which are also good.
So how to make it selective.
So of course when
people think of CRISPR,
one of the things they
think of right away
is human embryos, right?
How could it be used to go
in and snip out or change
expression of genes
and development?
And we know that there
have been two tests,
two groups that have worked
with human embryo-- well,
cell lines, at least--
and then they were shut down.
Melissa, do you
have any thoughts
about where that work is going?
Where the regulation is of it?
What should be happening?
How dangerous is that?
It'd be good if
you could comment
on where the community is
with working with that--
with human embryos and CRISPR.
I mean, I think as we've
said, the CRISPR technology
has changed how easy
it is to do this,
but it hasn't fundamentally
changed what's going on.
So I think there's
been discussion
about this from the time that
Zinc-fingers were first shown
to be able to change genomes.
And I think that we're still
a really long way from it.
I think it's always important
to have the discussion started
as soon as the possibility
arises about what that is,
but I think that,
honestly, there's
still a lot we don't know
about what specific changes
to the DNA and how they're
going to affect a developing
organism, let alone
a human, right?
There are interactions with
environment and other things,
and there are a large number
of very well-publicized
disease-causing genes
that might potentially
be well-known and be causative.
But I would say
for the most part,
we don't have a
handle well enough
to make a designer
baby at this point.
So I think that that's not
really on the forefront,
but people are certainly
talking about it.
And I think that's really the
most important thing, which
is to keep the discussion
and to involve the public.
Do you think there should
be some regulation upfront
before the science
proceeds or do you
think it's too soon for that?
Yes, and correct me
if I'm wrong, others,
but I believe that
there are regulations.
And so the work that has
been done in human embryos
has been on non-fertile
embryos, and that's not
been in the United States.
So in the United States, there
are very strict policies,
which is my understanding.
As I said, I work on
flies, but my understanding
is there are very strict
policies in place in the United
States and that these
experiments that
are making news are occurring
abroad where I don't think--
I don't know about
International regulations
on these sorts of procedures.
Keith, do you want to
weigh in on this question?
Do you have any thoughts
about it as well?
Yes, I think the only
thing I would add is just,
I mean, in the broader
arc of the conversation
is understanding the difference
between the germline cells
and non-germline cells.
And so editing the DNA in
my hand after I'm an adult
isn't passed on to
my progeny, where
editing germline DNA not
only affects me but affects
my progeny.
So there are implications there
that, as Melissa mentioned,
they're not new
implications, but I
think they're more
eminent because
of the ability of CRISPR.
And then the second
thing that people
have been trying to grasp
with regard to CRISPR is--
so James talked about
the drug delivery
aspect of getting the CRISPR
complex into the right cell,
but even once it's
in the right cell,
while it's a specific
system in terms
of where it targets
in the genome,
it's not perfectly specific.
And so we're still not
fully appreciating how
off-target editing might be
happening in these organisms.
And I know there's a lot
of effort in that area
because as we start
thinking about therapeutics,
understanding what the
new side effects are
and that these are now
genomic, inheritable side
effects is significant.
What do you mean by
off-target editing?
So in Melissa's example,
there was a particular gene
that she wanted to
target with GFP.
However, the guide
RNA sequence, which
is what targets the CRISPR
complex to where she wanted
to put the GFP, it may
target it to other parts
of the genome that have similar
sequences but not exactly
the same sequence.
And those events happen at a
lower frequency than the target
editing, but that
off-target editing then
could cause mutations
that were not anticipated.
Thank you for that
definition there.
I appreciate it.
That's obviously a
big concern, that you
be able to target very
precisely with your systems.
So now we have a
question that has
come in from Ann in
New York about funding,
and she's asking, "can
you talk about how
funding affects your work?
You're all relatively young,
early-ish career investigators.
Obviously, I'm going to ask you,
do you see this as a hot area?
Do you think the
funding will increase?
And how is funding
affecting the direction
you're going in with your
research using CRISPR?"
And maybe-- which one of you--
I didn't really target this.
Melissa perhaps?
Or any one of you have a
strong feeling about this?
I mean, I'm welcome
to talk about it,
but my research is mostly
funded in terms of its angle
in terms of asking
questions about development.
And for us, as I said, CRISPR
is very much a tool that
enables us to ask much
more precise questions,
and so I would say
that from all that I
have heard from colleagues and
friends, using CRISPR as a tool
is becoming--
not expected, but is
very, very commonplace
now in grant applications
and things like that.
It's almost moved so quickly
from the level of super-hot
as a tool to expected as a
tool that I think there's going
to be a little bit of
a correction, I think,
back in terms of people
recognizing that it's not
as straightforward as--
when you're working in an
organism, or in a cell line,
or in a bacteria,
there are complications
of working in a
biological system that
are going to make it not
as trivial as it sometimes
sounds on paper.
But I think in
general, there is going
to be a strong push to use
this technology because
of its power.
It does sound like
it's very much a tool.
You're not getting
funding for it as a tool.
You're getting funding
for interesting questions
that you're addressing using
this tool at this point, which
is very interesting.
We do have a question from
[? Euan ?] at Stanford--
Stamford, excuse
me, Connecticut.
"It sounds to me like
we're talking mostly
about these advancements
addressing diseases that will
impact small numbers of people.
Where does this
research scale in humans
without Congress slowing
it down for years?"
Now, I did not hear that.
I hear that it's still at
the very basic research
stages for disease, but let's
have James or Keith address
that, whichever one of you feels
that you can address how this
is impacting using CRISPR
to address therapeutics
for diseases.
Sure.
I'll be happy to jump in here.
So I think it's a little early
to predict which diseases
this is going to be useful for.
People have made
arguments that this is
going to be useful for cancer.
I can make strong arguments
for CRISPR-based cancer
therapeutics.
I can make strong arguments
against CRISPR-based cancer
therapeutics.
The same thing goes for
heart disease and so on.
So when you look at
the diseases that
affect a large
number of Americans
and a large number of
people around the world,
right now the science is still
too early, in my opinion,
to really predict,
all right, we're
going to be able to do x
for this disease, which
is a rare disease.
And we're not going
to be able to do
x for this other disease,
which is a more common disease.
There are also more practical
variables that influence this.
So as an example, if you
have a gene-editing drug,
that could have off-target
effects that we can't predict.
And if you have a rare disease
where there's no alternative,
there's no cure,
there's no nothing,
people may be more
willing to try it out.
But if you have
CRISPR for headaches
and you can just
take an aspirin,
people may be less
willing to try it out.
And so there are
practical things--
and that's an
oversimplification, obviously--
but there are practical
things like, what do we
have available on the market
now, that are going to impact
these things in ways that
we don't really understand
and, again, we can't
predict because in 15
years, the drugs that are
available that are not
gene-editing drugs,
just regular old drugs,
are going to be different
from the drugs we have now.
So it's difficult to predict the
future like that at this point,
in my opinion.
So well, Keith would
like to add in too.
Why don't you
address this question
and tell us about
the value of studying
this for therapeutics
in general or even
just for basic research?
Yes, James, and I felt how
you answered at the end
there, that the drugs we'll
have in 10 years, which
may not be CRISPR, but are
going to be different than what
we have today, I think
we can't overemphasize
how CRISPR is going
to enable us to answer
the fundamental
questions that will
help us determine what those
drugs are in 10 years that
will be--
even if the drug isn't
a CRISPR-based drug,
if how we got to that solution
was based on knowledge
we discovered by CRISPR,
that is really nice.
So I think that's great.
The second thing I wanted
to touch on is I think
we're thinking in the terms
of, I think, like a cancer,
a non-infectious disease and the
type of people that that might
affect, but there is fantastic
work going on at the Gates
Foundation--
funded by the Gates
Foundation, I should say--
trying to understand how to use
CRISPR to target different gut
microbes that cause diseases
in low-income countries
where things like
cholera and diarrhea
even can be deadly in children.
And so those are some examples
of things where antibiotics
are just not a
great tool to use,
and we're learning that
through antibiotic resistance.
And so this gives us a
new hook towards some
of those types of
infectious diseases
that I think is
very, very exciting.
Very exciting.
It sounds like
we're just beginning
to get a sense of the
sort of brave new world
that CRISPR is opening up, both
as a research tool, as Melissa
is showing us to
help her tag proteins
and to understand and
trace them on their journey
through development--
so illuminating
basic biological processes
to actual drug delivery
systems and all sorts of ways of
maybe thinking about disarming
microorganisms around us.
Very cool.
So I'm going to close.
On behalf of the
Alumni Association,
I want to thank you for
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Online, Alumni Edition.
A special thanks to our
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from Northwestern,
Wisconsin, and Georgia Tech.
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Thanks so much.
Thanks again for joining us.
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