WEBVTT

NOTE duration: "00:04:11.818"


NOTE Confidence: 0.94251996

00:00:05.519 --> 00:00:07.299
Stem cells are amazing cells.

NOTE Confidence: 0.94251996

00:00:07.440 --> 00:00:08.559
They are a very small

NOTE Confidence: 0.94251996

00:00:08.559 --> 00:00:09.760
number of cells in our

NOTE Confidence: 0.94251996

00:00:09.760 --> 00:00:10.260
bodies

NOTE Confidence: 0.8944067

00:00:11.039 --> 00:00:12.900
that have two special properties.

NOTE Confidence: 0.9742517

00:00:13.440 --> 00:00:14.559
The first one is they

NOTE Confidence: 0.9742517

00:00:14.559 --> 00:00:16.864
can self renew, namely whenever

NOTE Confidence: 0.9742517

00:00:16.864 --> 00:00:17.605
they divide

NOTE Confidence: 0.93240786

00:00:18.145 --> 00:00:19.185
they can make a copy

NOTE Confidence: 0.93240786

00:00:19.185 --> 00:00:19.765
of themselves.

NOTE Confidence: 0.9751436

00:00:20.224 --> 00:00:21.505
So they become so called

NOTE Confidence: 0.9751436

00:00:21.505 --> 00:00:23.845
immortal cells during our lifespan.

NOTE Confidence: 0.9855453

00:00:24.305 --> 00:00:25.585
And the second property is

NOTE Confidence: 0.9855453

00:00:25.585 --> 00:00:26.645
that they can generate

NOTE Confidence: 0.9390906

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many specialized cells or ordinary

NOTE Confidence: 0.9390906

00:00:29.585 --> 00:00:31.310
cells that are directly involved

NOTE Confidence: 0.9390906

00:00:31.310 --> 00:00:33.150
in tissue functions, and that's

NOTE Confidence: 0.9390906

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a process called differentiation.

NOTE Confidence: 0.9325591

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So because of these two

NOTE Confidence: 0.9325591

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key properties that make stem

NOTE Confidence: 0.9325591

00:00:37.870 --> 00:00:39.010
cells very special.

NOTE Confidence: 0.9816847

00:00:43.805 --> 00:00:45.085
My lab has worked on

NOTE Confidence: 0.9816847

00:00:45.085 --> 00:00:46.445
lots of things, but the

NOTE Confidence: 0.9816847

00:00:46.445 --> 00:00:48.364
common theme is working on

NOTE Confidence: 0.9816847

00:00:48.364 --> 00:00:49.425
the key genes

NOTE Confidence: 0.9731621

00:00:49.885 --> 00:00:51.965
that regulate the self renewing

NOTE Confidence: 0.9731621

00:00:51.965 --> 00:00:53.644
ability of stem cells. And

NOTE Confidence: 0.9731621

00:00:53.644 --> 00:00:55.585
particularly, we focus on,

NOTE Confidence: 0.9899256

00:00:56.364 --> 00:00:57.644
those genes which are not

NOTE Confidence: 0.9899256

00:00:57.644 --> 00:00:58.144
traditionally

NOTE Confidence: 0.95502526

00:00:58.445 --> 00:00:58.945
studied.

NOTE Confidence: 0.99277234

00:00:59.630 --> 00:01:00.610
Genetic information

NOTE Confidence: 0.98284554

00:01:01.230 --> 00:01:02.450
encoded in our DNA

NOTE Confidence: 0.9574889

00:01:02.989 --> 00:01:04.770
is then made into copies

NOTE Confidence: 0.99620676

00:01:05.150 --> 00:01:05.890
of blueprints

NOTE Confidence: 0.8288406

00:01:06.190 --> 00:01:07.950
called messenger RNA, guide the

NOTE Confidence: 0.8288406

00:01:07.950 --> 00:01:08.930
production proteins.

NOTE Confidence: 0.99908

00:01:09.310 --> 00:01:10.050
And this

NOTE Confidence: 0.8907983

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supposedly leads to the start

NOTE Confidence: 0.8907983

00:01:12.430 --> 00:01:13.569
of inter life process.

NOTE Confidence: 0.93320686

00:01:14.015 --> 00:01:15.694
But actually recently, we found

NOTE Confidence: 0.93320686

00:01:15.694 --> 00:01:16.655
that the story is not

NOTE Confidence: 0.93320686

00:01:16.655 --> 00:01:17.395
that simple

NOTE Confidence: 0.88323635

00:01:17.694 --> 00:01:19.694
because protein coding genes, they

NOTE Confidence: 0.88323635

00:01:19.694 --> 00:01:21.075
are not the entire

NOTE Confidence: 0.9535495

00:01:21.615 --> 00:01:22.895
picture of the secret of

NOTE Confidence: 0.9535495

00:01:22.895 --> 00:01:24.495
life. And they actually only

NOTE Confidence: 0.9535495

00:01:24.495 --> 00:01:26.175
occupies one percent of our

NOTE Confidence: 0.9535495

00:01:26.175 --> 00:01:27.535
genome. How about the other

NOTE Confidence: 0.9535495

00:01:27.535 --> 00:01:28.994
ninety nine percent of DNA?

NOTE Confidence: 0.9795923

00:01:29.430 --> 00:01:31.290
People used to, you know,

NOTE Confidence: 0.9024405

00:01:32.069 --> 00:01:33.190
show no function in the

NOTE Confidence: 0.9024405

00:01:33.190 --> 00:01:35.110
DNAs and call them junk

NOTE Confidence: 0.9024405

00:01:35.110 --> 00:01:37.209
DNAs. And recently, we discovered

NOTE Confidence: 0.9643019

00:01:37.750 --> 00:01:39.290
that so called junk DNA

NOTE Confidence: 0.9312254

00:01:40.230 --> 00:01:41.355
are hiding different kind of

NOTE Confidence: 0.9312254

00:01:41.355 --> 00:01:42.875
genes, and they're equally important.

NOTE Confidence: 0.9312254

00:01:43.035 --> 00:01:44.075
We have twenty three thousand

NOTE Confidence: 0.9312254

00:01:44.075 --> 00:01:45.435
genes in our human genome,

NOTE Confidence: 0.9312254

00:01:45.435 --> 00:01:46.555
but we have one million

NOTE Confidence: 0.9312254

00:01:46.555 --> 00:01:48.315
of jumping genes in this

NOTE Confidence: 0.9312254

00:01:48.315 --> 00:01:49.675
junk DNA. Now we found

NOTE Confidence: 0.9312254

00:01:49.675 --> 00:01:51.055
that they're very important function

NOTE Confidence: 0.9460175

00:01:51.355 --> 00:01:52.875
in regulating the protein coding

NOTE Confidence: 0.9460175

00:01:52.875 --> 00:01:53.375
genes.

NOTE Confidence: 0.90424806

00:01:57.440 --> 00:01:58.480
So we take a very

NOTE Confidence: 0.90424806

00:01:58.480 --> 00:01:59.460
systematic approach,

NOTE Confidence: 0.9326262

00:02:00.320 --> 00:02:01.700
namely that's a multidisciplinary

NOTE Confidence: 0.9997497

00:02:02.160 --> 00:02:02.660
approach

NOTE Confidence: 0.9889864

00:02:03.040 --> 00:02:04.900
from a methodology perspective.

NOTE Confidence: 0.95929426

00:02:05.360 --> 00:02:06.960
First, we usually use cell

NOTE Confidence: 0.95929426

00:02:06.960 --> 00:02:09.440
or developmental biology methods, like

NOTE Confidence: 0.95929426

00:02:09.440 --> 00:02:09.940
microscopy,

NOTE Confidence: 0.962969

00:02:10.639 --> 00:02:11.139
transplantation,

NOTE Confidence: 0.99518555

00:02:11.600 --> 00:02:12.660
or laser ablation

NOTE Confidence: 0.97617346

00:02:13.305 --> 00:02:14.825
to identify stem cells in

NOTE Confidence: 0.97617346

00:02:14.825 --> 00:02:15.325
tissues.

NOTE Confidence: 0.99227023

00:02:15.865 --> 00:02:17.225
And once we know where

NOTE Confidence: 0.99227023

00:02:17.225 --> 00:02:18.605
are the stem cells

NOTE Confidence: 0.9944517

00:02:18.905 --> 00:02:19.965
exactly located

NOTE Confidence: 0.9293218

00:02:20.264 --> 00:02:21.544
in the tissues, then we

NOTE Confidence: 0.9293218

00:02:21.544 --> 00:02:22.845
take a genetic approach

NOTE Confidence: 0.97797185

00:02:23.225 --> 00:02:24.745
to knock out genes in

NOTE Confidence: 0.97797185

00:02:24.745 --> 00:02:25.405
the genome

NOTE Confidence: 0.9022585

00:02:25.865 --> 00:02:27.739
to see which genes knock

NOTE Confidence: 0.9022585

00:02:27.739 --> 00:02:28.860
out will lead to stem

NOTE Confidence: 0.9022585

00:02:28.860 --> 00:02:30.459
cell defect. And then after

NOTE Confidence: 0.9022585

00:02:30.459 --> 00:02:32.000
that we take a molecular,

NOTE Confidence: 0.8667599

00:02:32.860 --> 00:02:33.360
biochemical,

NOTE Confidence: 0.9328053

00:02:33.819 --> 00:02:35.760
and also genomic approach

NOTE Confidence: 0.96574944

00:02:36.060 --> 00:02:37.660
to study how the gene

NOTE Confidence: 0.96574944

00:02:37.660 --> 00:02:39.180
looks like, what kind of

NOTE Confidence: 0.96574944

00:02:39.180 --> 00:02:40.300
function they will do when

NOTE Confidence: 0.96574944

00:02:40.300 --> 00:02:41.360
they make their proteins,

NOTE Confidence: 0.88762474

00:02:41.685 --> 00:02:42.965
and what will the protein,

NOTE Confidence: 0.95414066

00:02:43.605 --> 00:02:44.645
will be doing in the

NOTE Confidence: 0.95414066

00:02:44.645 --> 00:02:45.145
cell

NOTE Confidence: 0.9394345

00:02:45.605 --> 00:02:47.205
to make certain kind of

NOTE Confidence: 0.9394345

00:02:47.205 --> 00:02:48.885
stem cell structure or turn

NOTE Confidence: 0.9394345

00:02:48.885 --> 00:02:50.725
on off certain signaling pathways

NOTE Confidence: 0.9394345

00:02:50.725 --> 00:02:52.325
in stem cells. Recently, my

NOTE Confidence: 0.9394345

00:02:52.325 --> 00:02:53.765
lab also took on structural

NOTE Confidence: 0.9394345

00:02:53.765 --> 00:02:54.745
biology approach.

NOTE Confidence: 0.9933968

00:02:55.110 --> 00:02:57.110
We are using cryo electron

NOTE Confidence: 0.9933968

00:02:57.110 --> 00:02:57.610
microscopy

NOTE Confidence: 0.995406

00:02:58.230 --> 00:03:00.250
to study those key proteins

NOTE Confidence: 0.9605284

00:03:00.870 --> 00:03:02.569
that determine stem cell fate,

NOTE Confidence: 0.93684494

00:03:03.510 --> 00:03:05.030
how they look like, and

NOTE Confidence: 0.93684494

00:03:05.030 --> 00:03:06.010
how they function,

NOTE Confidence: 0.9762878

00:03:07.430 --> 00:03:09.425
is, you know, moved in

NOTE Confidence: 0.9762878

00:03:09.425 --> 00:03:10.465
three d and four d

NOTE Confidence: 0.9762878

00:03:10.465 --> 00:03:12.005
way, to really

NOTE Confidence: 0.97880787

00:03:12.465 --> 00:03:14.065
switch the function of other

NOTE Confidence: 0.97880787

00:03:14.065 --> 00:03:15.365
molecules in the cells.

NOTE Confidence: 0.91786796

00:03:20.360 --> 00:03:21.400
In my lab we have

NOTE Confidence: 0.91786796

00:03:21.400 --> 00:03:23.080
been focusing on when these

NOTE Confidence: 0.91786796

00:03:23.080 --> 00:03:24.600
stem cell genes are active

NOTE Confidence: 0.91786796

00:03:24.600 --> 00:03:25.900
in non stem cells,

NOTE Confidence: 0.96457165

00:03:26.360 --> 00:03:27.560
or when they are overly

NOTE Confidence: 0.96457165

00:03:27.560 --> 00:03:29.000
active in stem cells, what

NOTE Confidence: 0.96457165

00:03:29.000 --> 00:03:30.040
kind of cancer they will

NOTE Confidence: 0.96457165

00:03:30.040 --> 00:03:31.819
cause. And we found that

NOTE Confidence: 0.96457165

00:03:32.040 --> 00:03:32.540
many

NOTE Confidence: 0.8336752

00:03:32.965 --> 00:03:33.784
types of cancers,

NOTE Confidence: 0.9730788

00:03:34.644 --> 00:03:36.504
actually related to this.

NOTE Confidence: 0.98648864

00:03:36.885 --> 00:03:37.924
And so this is very

NOTE Confidence: 0.98648864

00:03:37.924 --> 00:03:39.224
exciting for us because

NOTE Confidence: 0.99865067

00:03:39.525 --> 00:03:41.224
it provides a new approach

NOTE Confidence: 0.9399911

00:03:41.685 --> 00:03:43.284
to understand and potential to

NOTE Confidence: 0.9399911

00:03:43.284 --> 00:03:44.984
treat cancers. Now we can

NOTE Confidence: 0.9399911

00:03:45.045 --> 00:03:46.344
use a small RNAs

NOTE Confidence: 0.9359125

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that specifically knock down these,

NOTE Confidence: 0.9359125

00:03:48.280 --> 00:03:49.900
overly active stem cell genes,

NOTE Confidence: 0.97843474

00:03:50.520 --> 00:03:52.280
and we see a tremendous

NOTE Confidence: 0.97843474

00:03:52.280 --> 00:03:53.640
impact. And so this is

NOTE Confidence: 0.97843474

00:03:53.640 --> 00:03:55.320
a method very different from

NOTE Confidence: 0.97843474

00:03:55.320 --> 00:03:55.960
the current,

NOTE Confidence: 0.9888838

00:03:56.280 --> 00:03:56.780
immunotherapy.

NOTE Confidence: 0.9219346

00:03:57.400 --> 00:03:58.760
We hope to actually develop

NOTE Confidence: 0.9219346

00:03:58.760 --> 00:04:00.600
or help develop a, a

NOTE Confidence: 0.9219346

00:04:00.600 --> 00:04:01.580
completely new

NOTE Confidence: 0.9948982

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type of targeted approach to

NOTE Confidence: 0.9948982

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cancer research.