Stem Cells, Jumping Genes, & RNA Regulation at the Lin Lab

Transcript

• 00:06Stem cells are amazing cells.
• 00:07They are a very small
• 00:09number of cells in our
• 00:10bodies
• 00:11that have two special properties.
• 00:13The first one is they
• 00:15can self renew, namely whenever
• 00:17they divide
• 00:18they can make a copy
• 00:19of themselves.
• 00:20So they become so called
• 00:22immortal cells during our lifespan.
• 00:24And the second property is
• 00:26that they can generate
• 00:27many specialized cells or ordinary
• 00:30cells that are directly involved
• 00:31in tissue functions, and that's
• 00:33a process called differentiation.
• 00:35So because of these two
• 00:36key properties that make stem
• 00:38cells very special.
• 00:44My lab has worked on
• 00:45lots of things, but the
• 00:46common theme is working on
• 00:48the key genes
• 00:50that regulate the self renewing
• 00:52ability of stem cells. And
• 00:54particularly, we focus on,
• 00:56those genes which are not
• 00:58traditionally
• 00:58studied.
• 01:00Genetic information
• 01:01encoded in our DNA
• 01:03is then made into copies
• 01:05of blueprints
• 01:06called messenger RNA, guide the
• 01:08production proteins.
• 01:09And this
• 01:11supposedly leads to the start
• 01:12of inter life process.
• 01:14But actually recently, we found
• 01:16that the story is not
• 01:17that simple
• 01:18because protein coding genes, they
• 01:20are not the entire
• 01:22picture of the secret of
• 01:23life. And they actually only
• 01:24occupies one percent of our
• 01:26genome. How about the other
• 01:28ninety nine percent of DNA?
• 01:29People used to, you know,
• 01:32show no function in the
• 01:33DNAs and call them junk
• 01:35DNAs. And recently, we discovered
• 01:38that so called junk DNA
• 01:40are hiding different kind of
• 01:41genes, and they're equally important.
• 01:43We have twenty three thousand
• 01:44genes in our human genome,
• 01:45but we have one million
• 01:47of jumping genes in this
• 01:48junk DNA. Now we found
• 01:50that they're very important function
• 01:51in regulating the protein coding
• 01:53genes.
• 01:57So we take a very
• 01:58systematic approach,
• 02:00namely that's a multidisciplinary
• 02:02approach
• 02:03from a methodology perspective.
• 02:05First, we usually use cell
• 02:07or developmental biology methods, like
• 02:09microscopy,
• 02:11transplantation,
• 02:12or laser ablation
• 02:13to identify stem cells in
• 02:15tissues.
• 02:16And once we know where
• 02:17are the stem cells
• 02:19exactly located
• 02:20in the tissues, then we
• 02:22take a genetic approach
• 02:23to knock out genes in
• 02:25the genome
• 02:26to see which genes knock
• 02:28out will lead to stem
• 02:29cell defect. And then after
• 02:30that we take a molecular,
• 02:33biochemical,
• 02:34and also genomic approach
• 02:36to study how the gene
• 02:38looks like, what kind of
• 02:39function they will do when
• 02:40they make their proteins,
• 02:42and what will the protein,
• 02:44will be doing in the
• 02:45cell
• 02:46to make certain kind of
• 02:47stem cell structure or turn
• 02:49on off certain signaling pathways
• 02:51in stem cells. Recently, my
• 02:52lab also took on structural
• 02:54biology approach.
• 02:55We are using cryo electron
• 02:57microscopy
• 02:58to study those key proteins
• 03:01that determine stem cell fate,
• 03:04how they look like, and
• 03:05how they function,
• 03:07is, you know, moved in
• 03:09three d and four d
• 03:10way, to really
• 03:12switch the function of other
• 03:14molecules in the cells.
• 03:20In my lab we have
• 03:21been focusing on when these
• 03:23stem cell genes are active
• 03:25in non stem cells,
• 03:26or when they are overly
• 03:28active in stem cells, what
• 03:29kind of cancer they will
• 03:30cause. And we found that
• 03:32many
• 03:33types of cancers,
• 03:35actually related to this.
• 03:37And so this is very
• 03:38exciting for us because
• 03:40it provides a new approach
• 03:42to understand and potential to
• 03:43treat cancers. Now we can
• 03:45use a small RNAs
• 03:47that specifically knock down these,
• 03:48overly active stem cell genes,
• 03:51and we see a tremendous
• 03:52impact. And so this is
• 03:54a method very different from
• 03:55the current,
• 03:56immunotherapy.
• 03:57We hope to actually develop
• 03:59or help develop a, a
• 04:01completely new
• 04:02type of targeted approach to
• 04:04cancer research.