Susan Lim: Transplant cells, not organs

So I was privileged to train in transplantation

under two great surgical pioneers:

Thomas Starzl,

who performed the world's first successful liver transplant

in 1967,

and Sir Roy Calne,

who performed the first liver transplant in the U.K.

in the following year.

I returned to Singapore

and, in 1990,

performed Asia's first successful

cadaveric liver transplant procedure,

but against all odds.

Now when I look back,

the transplant was actually the easiest part.

Next, raising the money to fund the procedure.

But perhaps the most challenging part

was to convince the regulators --

a matter which was debated in the parliament --

that a young female surgeon

be allowed the opportunity

to pioneer for her country.

But 20 years on,

my patient, Surinder,

is Asia's longest surviving

cadaveric liver transplant to date.

(Applause)

And perhaps more important,

I am the proud godmother

to her 14 year-old son.

(Applause)

But not all patients on the transplant wait list

are so fortunate.

The truth is,

there are just simply not enough donor organs

to go around.

As the demand for donor organs

continues to rise,

in large part due to the aging population,

the supply has remained relatively constant.

In the United States alone,

100,000 men, women and children

are on the waiting list for donor organs,

and more than a dozen die each day

because of a lack of donor organs.

The transplant community

has actively campaigned in organ donation.

And the gift of life

has been extended

from brain-dead donors

to living, related donors --

relatives who might donate an organ

or a part of an organ,

like a split liver graft,

to a relative or loved one.

But as there was still a dire shortage of donor organs,

the gift of life was then extended

from living, related donors

to now living, unrelated donors.

And this then has given rise

to unprecedented and unexpected

moral controversy.

How can one distinguish

a donation that is voluntary and altruistic

from one that is forced or coerced

from, for example,

a submissive spouse, an in-law,

a servant, a slave,

an employee?

Where and how can we draw the line?

In my part of the world,

too many people live below the poverty line.

And in some areas,

the commercial gifting of an organ

in exchange for monetary reward

has led to a flourishing trade

in living, unrelated donors.

Shortly after I performed the first liver transplant,

I received my next assignment,

and that was to go to the prisons

to harvest organs

from executed prisoners.

I was also pregnant at the time.

Pregnancies are meant

to be happy and fulfilling moments

in any woman's life.

But my joyful period

was marred by solemn and morbid thoughts --

thoughts of walking through

the prison's high-security death row,

as this was the only route

to take me to the makeshift operating room.

And at each time,

I would feel the chilling stares

of condemned prisoners' eyes follow me.

And for two years,

I struggled with the dilemma

of waking up at 4:30 am

on a Friday morning,

driving to the prison,

getting down, gloved and scrubbed,

ready to receive the body

of an executed prisoner,

remove the organs

and then transport these organs

to the recipient hospital

and then graft the gift of life

to a recipient the same afternoon.

No doubt, I was informed,

the consent had been obtained.

But, in my life,

the one fulfilling skill that I had

was now invoking feelings of conflict --

conflict ranging

from extreme sorrow and doubt at dawn

to celebratory joy

at engrafting the gift of life at dusk.

In my team,

the lives of one or two of my colleagues

were tainted by this experience.

Some of us may have been sublimated,

but really none of us remained the same.

I was troubled

that the retrieval of organs from executed prisoners

was at least as morally controversial

as the harvesting of stem cells

from human embryos.

And in my mind,

I realized as a surgical pioneer

that the purpose of my position of influence

was surely to speak up

for those who have no influence.

It made me wonder

if there could be a better way --

a way to circumvent death

and yet deliver the gift of life

that might exponentially impact

millions of patients worldwide.

Now just about that time,

the practice of surgery evolved

from big to small,

from wide open incisions

to keyhole procedures,

tiny incisions.

And in transplantation, concepts shifted

from whole organs to cells.

In 1988, at the University of Minnesota,

I participated in a small series

of whole organ pancreas transplants.

I witnessed the technical difficulty.

And this inspired in my mind

a shift from transplanting whole organs

to perhaps transplanting cells.

I thought to myself,

why not take the individual cells

out of the pancreas --

the cells that secrete insulin to cure diabetes --

and transplant these cells? --

technically a much simpler procedure

than having to grapple with the complexities

of transplanting a whole organ.

And at that time,

stem cell research

had gained momentum,

following the isolation of the world's first

human embryonic stem cells

in the 1990s.

The observation that stem cells, as master cells,

could give rise

to a whole variety of different cell types --

heart cells, liver cells,

pancreatic islet cells --

captured the attention of the media

and the imagination of the public.

I too was fascinated

by this new and disruptive cell technology,

and this inspired a shift in my mindset,

from transplanting whole organs

to transplanting cells.

And I focused my research on stem cells

as a possible source

for cell transplants.

Today we realize

that there are many different types of stem cells.

Embryonic stem cells

have occupied center stage,

chiefly because of their pluripotency --

that is their ease in differentiating

into a variety of different cell types.

But the moral controversy

surrounding embryonic stem cells --

the fact that these cells are derived

from five-day old human embryos --

has encouraged research

into other types of stem cells.

Now to the ridicule of my colleagues,

I inspired my lab

to focus on what I thought

was the most non-controversial source of stem cells,

adipose tissue, or fat, yes fat --

nowadays available in abundant supply --

you and I, I think, would be very happy to get rid of anyway.

Fat-derived stem cells

are adult stem cells.

And adult stem cells

are found in you and me --

in our blood, in our bone marrow,

in our fat, our skin and other organs.

And as it turns out,

fat is one of the best sources

of adult stem cells.

But adult stem cells

are not embryonic stem cells.

And here is the limitation:

adult stem cells are mature cells,

and, like mature human beings,

these cells are more restricted in their thought

and more restricted in their behavior

and are unable to give rise

to the wide variety of specialized cell types,

as embryonic stem cells [can].

But in 2007,

two remarkable individuals,

Shinya Yamanaka of Japan

and Jamie Thomson of the United States,

made an astounding discovery.

They discovered

that adult cells, taken from you and me,

could be reprogrammed

back into embryonic-like cells,

which they termed IPS cells,

or induced pluripotent stem cells.

And so guess what,

scientists around the world and in the labs

are racing

to convert aging adult cells --

aging adult cells from you and me --

they are racing to reprogram these cells

back into more useful IPS cells.

And in our lab,

we are focused on taking fat

and reprogramming

mounds of fat

into fountains of youthful cells --

cells that we may use

to then form other,

more specialized, cells,

which one day may be used as cell transplants.

If this research is successful,

it may then reduce the need

to research and sacrifice

human embryos.

Indeed, there is a lot of hype, but also hope

that the promise of stem cells

will one day provide cures

for a whole range of conditions.

Heart disease, stroke, diabetes,

spinal cord injury, muscular dystrophy,

retinal eye diseases --

are any of these conditions

relevant, personally, to you?

In May 2006,

something horrible happened to me.

I was about to start a robotic operation,

but stepping out of the elevator

into the bright and glaring lights of the operating room,

I realized

that my left visual field

was fast collapsing into darkness.

Earlier that week,

I had taken a rather hard knock

during late spring skiing -- yes, I fell.

And I started to see floaters and stars,

which I casually dismissed

as too much high-altitude sun exposure.

What happened to me

might have been catastrophic,

if not for the fact

that I was in reach of good surgical access.

And I had my vision restored,

but not before a prolonged period of convalescence --

three months --

in a head down position.

This experience

taught me to empathize more with my patients,

and especially those with retinal diseases.

37 million people worldwide

are blind,

and 127 million more

suffer from impaired vision.

Stem cell-derived retinal transplants,

now in a research phase,

may one day restore vision,

or part vision,

to millions of patients with retinal diseases worldwide.

Indeed, we live

in both challenging

as well as exciting times.

As the world population ages,

scientists are racing

to discover new ways

to enhance the power of the body

to heal itself through stem cells.

It is a fact

that when our organs or tissues are injured,

our bone marrow

releases stem cells

into our circulation.

And these stem cells

then float in the bloodstream

and hone in to damaged organs

to release growth factors

to repair the damaged tissue.

Stem cells may be used as building blocks

to repair damaged scaffolds within our body,

or to provide new liver cells

to repair damaged liver.

As we speak, there are 117 or so clinical trials

researching the use of stem cells

for liver diseases.

What lies ahead?

Heart disease

is the leading cause of death worldwide.

1.1 million Americans

suffer heart attacks yearly.

4.8 million

suffer cardiac failure.

Stem cells may be used

to deliver growth factors

to repair damaged heart muscle

or be differentiated

into heart muscle cells

to restore heart function.

There are 170 clinical trials

investigating the role of stem cells in heart disease.

While still in a research phase,

stem cells may one day herald

a quantum leap in the field of cardiology.

Stem cells provide hope for new beginnings --

small, incremental steps,

cells rather than organs,

repair rather than replacement.

Stem cell therapies

may one day reduce the need for donor organs.

Powerful new technologies

always present enigmas.

As we speak,

the world's first human embryonic stem cell trial for spinal cord injury

is currently underway

following the USFDA approval.

And in the U.K.,

neural stem cells to treat stroke

are being investigated in a phase one trial.

The research success that we celebrate today

has been made possible

by the curiosity and contribution and commitment

of individual scientists

and medical pioneers.

Each one has his story.

My story has been about my journey

from organs to cells --

a journey through controversy,

inspired by hope --

hope that, as we age,

you and I may one day celebrate longevity

with an improved quality of life.

Thank you.