-
How does a sea snail catch a fish?
-
I mean, it's a snail, so it's slow,
-
and the fish is not.
-
But yet, this happens.
-
Hidden under the sand is a cone snail.
-
And that orange thing you see
is kind of like a tongue.
-
We call it a proboscis.
-
It uses that to track and subdue
this unsuspecting fish.
-
In this predator-prey interaction,
-
these are clearly not
your garden variety [unclear].
-
These are assassins of the sea.
-
And their weapon of choice is venom.
-
Venom, like the venom you find
in venomous snakes and scorpions,
-
these sea snails, they use their venom
to subdue fish, worms
-
and other snails.
-
And the venom of these snails,
-
it's not just one thing,
-
it's actually a cocktail
of toxic molecules
-
that are packaged and delivered
-
through a false tooth called a radula.
-
You can think of the radulas
as hypodermic needles.
-
Now, no need to worry,
-
these snails are practicing
good needle habits,
-
because each radula is only used once.
-
Now from your own knowledge
about venomous organisms,
-
and the keep-you-up-at-night
fish-killing video that I just showed you,
-
you might think that venom
is dangerous and all bad.
-
Well, yes and no.
-
A more accurate way of thinking of venom
-
is to think of it as both
a supervillain and a superhero.
-
In my lab, we study the evolution
of venom in these sea snails
-
as a force for good.
-
Sounds like a stretch,
-
or maybe even snake oil,
-
but actually,
-
while there are snakes involved,
the product is legit.
-
One reason the venom product
is so successful
-
is that it transforms a physical warfare
into a biochemical one.
-
Where usually the predator-prey
interaction is one of brute force,
-
venom takes it to a molecular scale.
-
And it's not size that matters,
-
but the mixture of your venom arsenal.
-
The chemistry of the toxins
in your arsenal
-
is what's going to enable David
to conquer Goliath.
-
And in our scenario,
David is clearly the snail.
-
Another feature of venom
that makes it so successful
-
is that the toxins work
with the precision of a Swiss army knife.
-
And so these toxins,
-
they come for strongholds
that help an organism to function.
-
So they target blood,
-
brain and membranes.
-
Whether it's snail venom or snake venom,
-
they each have components
that can do things,
-
like, cause your blood to clot,
-
what we call hemotoxic.
-
Or they cause neurons in your brains
to not function normally,
-
what we call neurotoxic.
-
Or they have toxins that will poke holes
into the membranes of your cells,
-
causing them to rupture
and basically explode,
-
what we call cytotoxic.
-
Cellular explosion, people.
-
Now, if that is not all powerful
and all present,
-
nothing is.
-
Now a little about me,
-
and why I'm so obsessed with venom.
-
I grew up in New York City
-
with forced access
to the Natural History Museum.
-
I say forced access,
-
because I'm one of five kids,
-
and my parents used museums
as a form of childcare.
-
There were two rules:
-
Don't lose anybody
-
and meet mom and dad
at the African elephants
-
at 5.30, when the museum closes.
-
Those totally unsupervised days
running through the halls of the museum
-
were full of adventure and exploration.
-
And that's how I feel
when I'm studying venom.
-
It's a scientific adventure.
-
We're boldly exploring this entity
that connects nature and humanity.
-
Another reason
that I'm obsessed with venom
-
is because of its duality.
-
When you inject the components
of a venom arsenal into an organism,
-
it can kill or it can cure.
-
At a molecular level,
several things can happen.
-
You saw one thing, paralysis in the fish.
-
Now that was happening
because the toxins in the venom
-
were attacking how the fish's cells
communicate with each other,
-
preventing it from swimming away.
-
Are there other things
that I would like to use venom to attack?
-
For sure.
-
And one of those is cancer.
-
Cancer tumors are cells.
-
And like all cells,
-
they communicate with themselves
and their environment around them.
-
So we would like to find venom components
-
that are very good at disrupting
how the tumor cells communicate.
-
Similar to how the venom disrupted
how the fish cells communicated
-
and the fish couldn't swim away.
-
In my lab, we study cancer
as a channelopathy.
-
What this means is basically
we're looking for venom components
-
that will target channels
that are overexpressed in tumor cells
-
versus normal cells.
-
The cancer that we're most
focused on right now
-
is liver cancer.
-
And that's because since the 1980s,
-
the death rate of liver
cancer has doubled,
-
and it's an emerging threat in the US.
-
In a screen in which we had cervical,
-
neuroblastoma, prostate
and liver cancer cells,
-
we found a compound from a terebrid snail
-
that seems to attack liver cancer cells
-
and only liver cancer cells
-
and none of the others that were tested.
-
And then, when we took this compound
and we injected it into mouse models
-
that were expressing liver cancer cells,
-
it significantly inhibited
the growth of the tumors.
-
We're not quite sure how this works yet,
-
we're still investigating the mechanism
-
and how we can make
this compound more effective,
-
so you can't rush out to the pharmacy
-
and order up a killer snail
liver-cancer therapy treatment.
-
Not yet.
-
Basically, what we think is happening
-
is that the compound is blocking
a specific channel,
-
prohibiting the transmission
of a specific chemical
-
that leads to downstream signaling
-
that enables the tumor to multiply
and draw blood to itself.
-
What we're doing in studying
the components of venom
-
to find treatments for human
diseases and disorders,
-
is not new,
-
it's what we call natural
products drug discovery,
-
and it's been happening for centuries
-
and in cultures all over the world.
-
Venoms are not only giving us
cool new compounds,
-
but they're also giving us
new ways of thinking
-
about how we treat
human diseases and disorders.
-
And I'll give you three examples.
-
The first is from killer
snails, of course.
-
And so the first drug from these snails
that is on the market
-
is called Ziconotide, or Prialt,
-
and it's used to treat chronic pain
in HIV and cancer patients.
-
Prialt is a nonaddictive pain therapy.
-
Three magic words when you think
about how we're treating pain currently.
-
We're using things that have
a huge cost of addiction.
-
So think of morphine
-
or think of any of your favorite
opioid out there.
-
What the snails have done
-
is they've shown us a way to treat pain
without the addiction,
-
which is huge.
-
The next example comes
from the Brazilian pit viper.
-
From these snakes, we've derived
a compound called Captopril.
-
Captopril is used to treat
high blood pressure,
-
and Captopril is a breakthrough drug.
-
But not only in and of itself,
-
but because it advanced
a whole class of drugs,
-
what we know as ACE inhibitors,
-
which are the most commonly described
for treating hypertension
-
and heart failure.
-
The last example is from the Gila monster.
-
And this is a really exciting example
of understanding the ecology
-
of these organisms
-
and pairing it with efficient
drug discovery.
-
And Gila monsters are binge eaters.
-
So when they bite into a large meal,
-
they release things in their venom
that lowers blood sugar.
-
So what's the drug that you think
we found from the Gila monster?
-
A compound that is used to lower
the blood sugar in diabetic patients.
-
Now these are three marvelous examples,
-
but we've just scratched the surface.
-
There's so much more venom
out there for us to study.
-
In fact, we think that 15 percent
of all the animals on the planet
-
are venomous.
-
And I think this is a low estimate,
-
given the fact that we haven't surveyed
all the animals on the planet.
-
But nature seems to have found
something that she likes,
-
and she's repeated it over
and over and over again,
-
leading to the vast array of animals
that we see around us
-
and all throughout the tree of life.
-
So whether we're talking
about my fave, killer snails,
-
or jellyfish,
-
or the larvae of butterflies and moths,
-
or platypus or slow walruses,
-
whether by sea, land or air,
-
you're sure to encounter
a venomous creature.
-
Remember when I told you
-
that venom can be both
a superhero and a supervillain,
-
and you doubted me?
-
Mhm.
-
We're in a race to harness
all of this venom goodness
-
before we lose the vast majority
of animals on our planet.
-
It's a holistic process.
-
You can't have the therapeutic treatments
-
without having the animals.
-
And you can't have the animals
-
without having their ecosystems.
-
So for me and the snails,
-
what it means is
we have to save the oceans.
-
And because venomous animals
are found everywhere,
-
we basically have to save the planet.
-
So do it for the venomous animals,
-
if you don't want to do it for yourself.
-
And who knows,
-
some day, snail venom
might just save your life.
-
Thank you.