A Role of Radiofrequency Ablation in Benign and Malignant Thyroid Diseases and Towards Precision Treatment of Cancer: A Novel Oncogenic Mechanism Mediated by Piwi Proteins

Transcript

• 00:00Search and we'll start with our first
• 00:03Speaker, Doctor Grace Lee Doctor Lee.
• 00:05As many of you may know is an assistant
• 00:08professor in endocrine surgery.
• 00:10She received her medical degree from the
• 00:13University of Oklahoma College of Medicine,
• 00:16did her her clinical training,
• 00:18residency in Research Fellowship
• 00:19at the Brigham and Women's
• 00:21Hospital at Harvard Medical School,
• 00:23and then did her fellowship in
• 00:25endocrine surgery at the male clinic.
• 00:28Before we were very fortunate,
• 00:30obviously, to recruit her here.
• 00:32TL Doctor Lee is is really an innovative
• 00:35expert and endocrine surgery and
• 00:37is looking at new ways to combat.
• 00:40Obviously thyroid, parathyroid,
• 00:41cancer among others,
• 00:42and seeing how we can, you know,
• 00:45leverage new techniques to
• 00:47improve the care patients,
• 00:48and I have a firmer understanding
• 00:50of the disease and Grace.
• 00:52I want to thank you for taking
• 00:55the time to join us for cancer,
• 00:58grand rounds and welcome hearing you talk.
• 01:03Thank you that confuse.
• 01:05That was very kind introduction.
• 01:08I am delighted to be able to
• 01:11present an area of my clinical
• 01:14interest with everyone.
• 01:19Share my screen.
• 01:25Works.
• 01:29Alright, so my name is Grace Lee.
• 01:32I am a new ish endocrine surgeon to Yale.
• 01:37I joined I was very fortunate
• 01:41to join Yale earlier this year.
• 01:44Sort of at the height of the
• 01:47pandemic from Tulane Medical Center,
• 01:50down in New Orleans and I have been an
• 01:54early adopter of this new technique,
• 01:58called Radiofrequency Ablation
• 01:59in thyroid at Tulane.
• 02:01So I just wanted to share my experience
• 02:05and what I know about where you
• 02:08frequency ablation so hopefully
• 02:10we can also start this treatment.
• 02:14At Yale as well. I have no disclosures.
• 02:21My talk will briefly touch
• 02:23on several different areas.
• 02:25I'll just touch on the
• 02:27background of how the RFA works.
• 02:30The physics and mechanism and brief history.
• 02:35Current procedural guidelines.
• 02:37When we are deploying something
• 02:41knew there are governing bodies who.
• 02:45Guide us as far as indications and when
• 02:48not to do it or concerned and will cover
• 02:52why we should be looking into this.
• 02:56What are the risks and the advantages
• 02:59and will also visit efficacy and safety
• 03:02of this technique as well as I'll
• 03:06show you a little video clip of how
• 03:09this is done and future directions.
• 03:14Super Cutaneous Ablation is a technique
• 03:17that obviates the need for a surgery an
• 03:21I'm sure many of you are familiar with.
• 03:25These needle often imaging guided.
• 03:29Way of eliminating undesirable
• 03:32tissue of their multiple different
• 03:35ways of burning or zapping things,
• 03:38we have utilized laser,
• 03:40microwave cryotherapy,
• 03:41freezing it, burning it,
• 03:43even injecting ethanol to a
• 03:46chemical esclerosis things,
• 03:48or Hifu which is high intensity
• 03:52focused ultrasound.
• 03:53Today we are going to focus
• 03:57on radiofrequency ablation,
• 03:58which is on the spectrum of these
• 04:02energy harnessing ablation techniques.
• 04:05Radiofrequency just a brief.
• 04:07Physics is concentrating heat or thermal
• 04:11energy at the tip of an electrode catheter.
• 04:15By alternating current and this
• 04:19frictional heat that gets generated
• 04:23from ionic molecules will.
• 04:26Turn into conductive heat from
• 04:28this frictional heat and create
• 04:31this Adelaide of unit.
• 04:33An if you sustain this heat
• 04:35enough in that area,
• 04:37this thermal energy will.
• 04:40Cause irreversible cellular damage,
• 04:42so essentially coagulations
• 04:44necrosis but without charring the
• 04:47tissue or carbonation of tissue.
• 04:51Radiofrequency Ablation in medicine.
• 04:52Interesting Lee has been utilized
• 04:54for a long time.
• 04:56It has been around in medicine for over
• 04:5975 years and some of the areas that.
• 05:03Have already started using
• 05:05regular frequency ablation.
• 05:07Are wide cardiology started using
• 05:10this for a rythmia vascular surgery?
• 05:13Surgeons use for varicose veins.
• 05:17Orthopedic surgeons an for us
• 05:20there uncle logic purposes for
• 05:22radiofrequency ablation that you may
• 05:25be familiar with for either meta,
• 05:29static or primary liver lesions
• 05:31in pulmonary Mets, Adrenal Mets,
• 05:34solitairy,
• 05:35renal lesions as well as Barrett's esophagus.
• 05:40History of thyroid RFA is not
• 05:43as deep as the history of RFA
• 05:47in other parts of the body.
• 05:502001 was kind of burst here.
• 05:53I am at year for thyroid RFA.
• 05:57The paper at the top for Catania's
• 06:01radio frequency evolution of the fire.
• 06:04Guided ultrasound is single animal report.
• 06:07The animal used was a pig. In Japan.
• 06:12And that this was just a proof of concept.
• 06:16Is radiofrequency ablation feasible?
• 06:18Is this safe?
• 06:19In subsequently.
• 06:20It's interesting that our colleagues at
• 06:24ground both Interventional radiology
• 06:26and surgery Department got together and
• 06:30try this RFA in recurrent thyroid tumors.
• 06:34So this technique has been utilized.
• 06:37Has been kind of played with
• 06:40for now nearly two decades.
• 06:44The person who actually took it
• 06:46and ran with it is this physician
• 06:49Interventional radiologist after Beck.
• 06:51Doctor Beck is located in
• 06:54Austin Medical Center in Seoul,
• 06:56Korea.
• 06:56He himself also had multiple benign
• 07:00thyroid nodules and about 25 years
• 07:03ago he was recommended by Korean
• 07:05surgeons to undergo a thyroid surgery
• 07:08an he did not want to surgery,
• 07:11so he started looking into what other ways?
• 07:14Are there to eliminate thyroid nodule
• 07:17and he started to focus on RFA.
• 07:20Not only he started doing this for.
• 07:23Patience.
• 07:24He himself has undergone this treatment
• 07:27so he has been really transparent
• 07:30about the results of RFA and he has
• 07:34been a passionate advocate for how this.
• 07:37Technique should be utilized an efficiently,
• 07:40safely and he has given multiple talks.
• 07:44He's been the most prolific.
• 07:47Writer in the RFA.
• 07:49Literature for this technique.
• 07:51So in 2009, the Korean Society of
• 07:54thyroid radiology came up with
• 07:57recommendations for how Virat RFA
• 08:00should be deployed and in 2012
• 08:03they came up with the 1st edition
• 08:06of guidelines for thyroid RFA.
• 08:08In 2017, they revised the guidelines
• 08:11and came up with a more updated
• 08:15version of thyroid RFA guidelines.
• 08:17Since then, this technique has been
• 08:20utilized worldwide in multiple
• 08:22hands-on teaching sessions,
• 08:24and workshops have been taught
• 08:27by Doctor Beck in others.
• 08:29So Japan, Taiwan.
• 08:31Obviously,
• 08:31a lot of Asian countries as
• 08:34well as European countries have
• 08:37embraced this technique,
• 08:39and it has slowly gotten to the US as well.
• 08:45So last year this is obviously pre
• 08:49kovid medical conference that we
• 08:51don't have anymore group picture
• 08:54folks from all over the world came
• 08:57together for this Korean Society of
• 09:00ultrasound in medicine conference case.
• 09:02Some insult and I was fortunate
• 09:05to participate in this conference
• 09:07in learn RFA from this conference
• 09:10as well as Doctor Beck afterwards.
• 09:14So there is a great interest and.
• 09:18The things that I have learned
• 09:20in the collaboration in the
• 09:22friendships that I have made.
• 09:25In Korea have been invaluable.
• 09:28And it really has helped me a lot
• 09:30in a deploying this technique at
• 09:33my prior institution at Tulane.
• 09:35So in 2015, Italian radiologists,
• 09:38an endocrinologist,
• 09:39came up with a consensus opinion
• 09:43an in the UK.
• 09:45They came together and consolidated
• 09:48recommendation in 2016 and 2017 in Australia.
• 09:52So what about us? What about the US?
• 09:56Why are we not widely adapting RFA?
• 10:00Why are we just now catching on?
• 10:04So.
• 10:05There are multiple reasons as to why
• 10:08the US sort of has lagged behind
• 10:12in adaptacion of this technique.
• 10:15It's not that clinicians in the
• 10:18US have not heard of it,
• 10:21it's just that we have been a
• 10:24little bit more cautious and.
• 10:27As of late,
• 10:29just in the past couple years there
• 10:32has been a booming interest in RFA
• 10:35technique by multiple societies
• 10:38who deal with thyroid pathology.
• 10:41An I'm sure that this RFA technique
• 10:44will be widely deployed and widely utilized,
• 10:48and I hope that yell will also start
• 10:53offering this treatment as well soon.
• 10:57So the.
• 10:58A Sentinel event that kind of
• 11:01took off the interest in the USI
• 11:05believe is this paper which came
• 11:08out of Mayo Clinic in 2018.
• 11:11The group here are comprised of
• 11:14endocrine endocrinologist who
• 11:16actually do their own.
• 11:17FN eisen utilizes ultrasound in
• 11:20clinic to assess thyroid nodules as well as.
• 11:24Prominent Interventional radiologists
• 11:27they have.
• 11:29Published this case series comprising
• 11:3314 patients over the years of
• 11:382013 and 2016 in their result.
• 11:42Really has been terrific.
• 11:45They achieve volume reduction by 45%.
• 11:50As early as eight months and Durably
• 11:54at couple years out in very safely,
• 11:57so I think this paper actually sort
• 12:00of put RFA on the map for the US,
• 12:04clinicians and audience.
• 12:05So since then,
• 12:07there has been many workshops
• 12:09and conferences,
• 12:10and as of late I have been getting.
• 12:15Presentation notices almost monthly,
• 12:17so why are we excited about RFA like?
• 12:21What are the advantages?
• 12:23So one advantage that I as
• 12:26a surgeon really appreciate,
• 12:29is that patients have.
• 12:32Lower anxiety about undergoing a per
• 12:35cutaneous minimally invasive treatment
• 12:37rather than undergoing a surgery.
• 12:40Most of my patients,
• 12:42unlike patients in Korea,
• 12:44are a little bit less concerned
• 12:47about the cosmetic outcome.
• 12:49The scar after surgery,
• 12:51but they are still very anxious
• 12:55about just the prospect of
• 12:57having to undergo a surgery so.
• 13:01I think this technique,
• 13:03if the patient qualifies for it,
• 13:06will be highly beneficial from
• 13:08reducing anxiety perspective,
• 13:09and obviously this is
• 13:11percutaneous needle poke.
• 13:13There won't be a long.
• 13:17Scarred that will be left behind.
• 13:19Of course,
• 13:20in thyroid treatment world there
• 13:23has been a couple of modalities
• 13:27where we're taking out thyroid
• 13:31through the armpit axilla incision
• 13:34through the mouth transoral.
• 13:38Method,
• 13:38but each one of those scarless or
• 13:42scar hiding surgeries come with
• 13:45either an increased cost of robot
• 13:49deployment or longer surgery,
• 13:52longer recovery, etc.
• 13:54So those are.
• 13:57They probably have a role in
• 14:01the world of Barry.
• 14:03Treatment,
• 14:04but they're still not as optimal
• 14:07if the patient is truly aiming for
• 14:10the best cosmetic cosmetic outcome,
• 14:13and it's a needle poke,
• 14:16minimally invasive.
• 14:17There is no hospital admission for some
• 14:21of the thyroid surgeries that we do,
• 14:24of course, are outpatient, but.
• 14:28There is still recovery involved
• 14:30after general anesthesia.
• 14:32There is pain involved.
• 14:34But with this for Catania's technique of RFA,
• 14:37there is no general anesthesia.
• 14:39There is only one institution
• 14:41in the US currently.
• 14:43Who's doing this RFA under
• 14:45general anesthesia in Korea?
• 14:47This RFA is actually done in a
• 14:51clinic setting with no Mac sedation
• 14:54just under local anesthesia.
• 14:56It's a relatively short procedure,
• 14:59obviously is volume of the thyroid
• 15:01nodule dependent bigger to nodule,
• 15:03longer to procedure,
• 15:05but it's a relatively short procedure.
• 15:07I would say anywhere from 10
• 15:10minutes to 30 minutes per nodule.
• 15:13And repeat ablation is a possibility,
• 15:16so you're not burning any
• 15:19bridges if the first go.
• 15:22Does not workout for the patient.
• 15:25No hyper para no hypothyroidism,
• 15:28which is remarkable because we are
• 15:31only ablating the nodule in preserving
• 15:34the normal parenchyma of the thyroid.
• 15:37Is virtually unheard of to
• 15:40get hypothyroidism after RFA.
• 15:42Treatment in also because
• 15:45it's nodule specific.
• 15:47There's no hypoparathyroidism either,
• 15:49so minimal complication risk.
• 15:51There could be voice changes
• 15:54and temporary discomfort,
• 15:56but compared to surgery I would say
• 16:01it's either equivalent or less and
• 16:05overall lower cost and that comes from.
• 16:10Not admitting the patient no
• 16:13prolonged or time or anesthesia,
• 16:16etc.
• 16:18So what are the downsides to RFA the risks?
• 16:22There are several.
• 16:25I just mentioned that repeat
• 16:27procedure is a possibility,
• 16:29but sometimes it's a necessity.
• 16:31So just one go around.
• 16:34It may not be enough to achieve
• 16:37therapeutic effect,
• 16:37so obviously having to do a repeat
• 16:40procedure is a risk an I would also
• 16:44say that is operator dependent.
• 16:46Many procedures are operator dependent
• 16:48surgeries or operator independent and
• 16:51that's why we advocate for.
• 16:55High volume Endocrine Surgeons to be doing
• 16:59endocrine procedures just the same with RFA.
• 17:02The more fast I'll the operator is
• 17:05with ultrasound and needle guidance,
• 17:08the better the outcome will be in.
• 17:11Some patients may not be able to
• 17:14tolerate a procedure without sedation,
• 17:17whether it's related to pain or anxiety is.
• 17:21Quite interesting to see them stoic nature
• 17:24of these Korean patients that I observed
• 17:27that Awesome Medical Center last year.
• 17:30I know that 18 gauge needle that's
• 17:33almost looking like a harpoon hurts,
• 17:35but they were very stoic.
• 17:37They said that they're not having any
• 17:40pain and they tolerate it just fine,
• 17:43but when I have been doing fine
• 17:46needle aspiration, thyroid nodule,
• 17:48biopsies in clinic setting although
• 17:50is 27 gauge needle much finer.
• 17:52Many of the patients complain of pain,
• 17:54so it will be interesting to see how
• 17:57many patients can actually tolerate this
• 17:59kind of a procedure without sedation.
• 18:02Complications when there is something
• 18:04being done to any part of the body.
• 18:07There could be associated complications.
• 18:09Overall rate is pretty smaller 2 to 3%,
• 18:12which is probably equivalent
• 18:14to a surgical treatment.
• 18:16There could be dis phonia which is
• 18:19about 1% in this data is coming.
• 18:22This data is coming from multi
• 18:24institutional pulled data so about
• 18:261% and none of it was permanent.
• 18:29It was all temporary resolved after.
• 18:322 three months hematoma.
• 18:34Thyroid is very vascular Schimborn.
• 18:37That's probably a little bit more prevalent
• 18:40in RFA setting rather than a surgery.
• 18:43There are a couple of lower incident
• 18:47complications such as tumor rupture,
• 18:49which is unheard of in surgery,
• 18:52hypothyroidism, Abscess,
• 18:53Anna couple of anecdotal not
• 18:55reported in this study.
• 18:57Complications such as tracheal injury
• 19:00and brachial plexus injury when a
• 19:03new technique is being deployed.
• 19:05In multiple people are just trying it out.
• 19:08I think that there will be wide.
• 19:13A variety of complications that may arise,
• 19:15as well as the outcome.
• 19:18So RFA in thyroid.
• 19:20There are guidelines and indications,
• 19:23and most of it is based on
• 19:262017 revised Korean guideline.
• 19:28So these are indications that
• 19:30most experts agree that we should
• 19:33be doing this for benign thyroid
• 19:36nodules causing compressive symptoms.
• 19:38If the patient has cosmetic concern
• 19:42and the nodule should be of size
• 19:46at least 2 centimeter or so.
• 19:48An if it's enlarging but has benign cytology,
• 19:52but.
• 19:53We have not set any definitive
• 19:56maximum thyroid nodule size for
• 19:58the treatment and Rica.
• 20:00Insist after failure of ethanol.
• 20:03Ablation of experts will agree that
• 20:06ethanol revelation is more studied,
• 20:09more tridan,
• 20:10better method for recurrent cyst or.
• 20:14Cyst of the thyroid treatment
• 20:17rather than rfa.
• 20:19Autonomously functioning thyroid nodule.
• 20:21This is toxic nodule indication.
• 20:24I personally have tried.
• 20:27Rfa in toxic nodule.
• 20:30It works beautifully and.
• 20:33That's sort of made me a believer
• 20:36of RFA technique.
• 20:37Entirety of nodule should be visible
• 20:40on ultrasound for safety concerns.
• 20:42It should not have any substernal
• 20:44component in.
• 20:45Nodule should be sufficiently away
• 20:47from the vital structures in the neck.
• 20:50As you all know,
• 20:52there are nerves and.
• 20:55Vital blood vessels in the neck and.
• 20:59Since the Heat can transmit,
• 21:02it is important that the structures are
• 21:06constantly being observed and monitored so.
• 21:10We don't cause any.
• 21:14Undesirable damages.
• 21:16RFA is most effective in solid nodules and
• 21:19if the nodule contains macro calcifications,
• 21:23the RFA will not be as effective.
• 21:26Ideal candidate.
• 21:27The pathologic criteria we want to.
• 21:30Be 100% sure that it is benign
• 21:33by either 2 repeated ultrasound
• 21:36guided F na's and in Korea.
• 21:39What they do is core needle biopsy.
• 21:43This is not universally practiced.
• 21:46Way of establishing benign
• 21:48status of the thyroid nodule.
• 21:51But core needle biopsy is an alternative
• 21:56to a fine needle aspiration and
• 21:58we want to make sure that there
• 22:01isn't any sonographic features or
• 22:04malignancy seen prior to deploying RFA.
• 22:07And again,
• 22:08we want to make sure that surrounding
• 22:11critical structures are away from harm.
• 22:14Or if a guidelines so multiple
• 22:18different countries are coming up with.
• 22:21Guiding this RFA treatment to be deployed.
• 22:25Obviously,
• 22:26Korean guideline is the most comprehensive
• 22:29Italians Australians aace American
• 22:32Association of clinical endocrinologists.
• 22:34We have a little bit of more conservative.
• 22:41Recommendations for RFA.
• 22:43So we are currently only recommending
• 22:46RFA to be used for benign thyroid
• 22:49nodules that are causing cosmetic
• 22:51or cosmetic concerns or symptoms and
• 22:54should be biopsy proven to be benign.
• 22:58Contraindications who cannot
• 23:00undergo this procedure.
• 23:02Pregnant females if the patient
• 23:04has contralateral vocal cord palsy
• 23:07if the nodule is not seen in its
• 23:10entire T but the patient has
• 23:13cardiac implanted cardiac device.
• 23:16We can switch over to bipolar mode
• 23:19instead of regular monopolar electrode
• 23:22or deploy it in shorter bursts in
• 23:26lower energy or if the patient has.
• 23:29Anticoagulation onboard is should be
• 23:31stopped prior to RFA the indeterminate
• 23:34thyroid nodule is a Gray area.
• 23:37There has been a study published
• 23:40in Europe but it's just a limited
• 23:43number of patients and the Efficacy
• 23:46and the long term outcome of.
• 23:49Doing Arefeen indeterminate
• 23:50thyroid nodule has not been
• 23:52quite established and malignancy.
• 23:54We are pushing a little bit of
• 23:57the boundary on this malignancy.
• 24:00A territory, so I'll discuss that briefly,
• 24:03since we are under the umbrella of
• 24:06Smilow Cancer Center, RFA and thyroid.
• 24:09When we are dealing with toxic Nodules,
• 24:12Orix beautifully.
• 24:14If we can achieve at least 50
• 24:17to 80% volume reduction of TSH
• 24:20normalizes an by 12 months.
• 24:22Most people are euthyroid, but again.
• 24:26If your desire is to achieve immediate
• 24:29reversal of thyrotoxicosis or hyperthyroidism
• 24:31than RFA is not the way to go.
• 24:35An it may take a one more
• 24:37than one ablation session.
• 24:40Depending on the size,
• 24:42and oftentimes these toxic nodules
• 24:44tend to be a little bit on the larger
• 24:48side greater than 4 centimeter,
• 24:50so in that case combination of
• 24:52RF NRA I can be entertained.
• 24:56Or large toxic goiters.
• 24:58This is how the electrode of rfa works, and.
• 25:05And how the picture shows you how fine it is.
• 25:10This is much finer than then liver
• 25:15RFA electrode an this just purely.
• 25:19Equipment optimization is what has taken
• 25:24the RFA deployment in thyroid lag behind.
• 25:30Compared to the liver world,
• 25:32so this electrode is internally cooled,
• 25:35is about 18 gauge.
• 25:37Big and seven centimeter in length.
• 25:40So if we're dealing with a.
• 25:43Very big patient that comes into play.
• 25:48So liver has deployment of times whereas.
• 25:55Rfa in thyroid. We are actually
• 25:59introducing the electrode and.
• 26:01Pulling it out,
• 26:03which is called a moving shot technique.
• 26:06To ablate units, these are
• 26:10circles of ablation zone inside.
• 26:14The thyroid nodule.
• 26:16And you see the triangle containing recurrent
• 26:19laryngeal nerve and esophagus below.
• 26:21So those are the vital structures
• 26:24that we want to be avoiding.
• 26:28This is a brief video of mixed
• 26:32thyroid nodule that is undergoing.
• 26:35Radiofrequency ablation you see from the S
• 26:40make side introduction of the electrode.
• 26:43We want to be able to see the entire
• 26:47length of the catheter an it is.
• 26:50Introduced and.
• 26:55Treated ablated from posterior.
• 26:59To anterior and.
• 27:05Inferior to superior,
• 27:07so we actually ablate the
• 27:11entire ellipsoid thyroid nodule.
• 27:14Follow up, we do serial ultrasound
• 27:16to make sure there is and there is
• 27:20an adequate resolution of whatever
• 27:23the pathology said is being treated.
• 27:26In there is a concern for regrowth
• 27:29and that is partially due to
• 27:32inadequate ablation at the periphery.
• 27:35So incomplete evolution of the
• 27:39thyroid nodule is being advocated.
• 27:42I'll touch briefly on the Barid
• 27:45malignancy and RFA currently in the US.
• 27:47Not many centers are doing
• 27:49RFA for thyroid malignancy,
• 27:51however it has been done in other
• 27:54countries and more and more folks are
• 27:56pushing the envelope especially in
• 27:58the world of Micropapillary Carcinoma
• 28:01which is less than one centimeter if
• 28:04the micro papillary thyroid carcinoma
• 28:06is intra fire Riddle and there is no
• 28:10clinical or ultrasound evidence of.
• 28:12Lymph nodes spread the current American
• 28:15Thyroid Association guidelines say
• 28:18that you can either observe it with
• 28:21active surveillance or have the patient
• 28:23undergo a thyroid lobectomy overtime.
• 28:26We have found that even the patients
• 28:29who undergo active surveillance,
• 28:31there is about 13% operation rates.
• 28:34So instead of.
• 28:36Having these patients undergo an operation,
• 28:40why not RFA so?
• 28:44Clinicians overseas have published
• 28:47their data on Micro PTC,
• 28:50and the data is knew and not.
• 28:55Has garnered wider.
• 28:58Adaptation just yet,
• 28:59but I think it is coming in
• 29:02recurrent thyroid cancer.
• 29:04As a surgeon, you know redo reop
• 29:07neck or cancer is a bear territory.
• 29:10So if we can safely treat patient with
• 29:13percutaneous method it will be fantastic.
• 29:16Indeterminate Nodules as I briefly mentioned.
• 29:18There is lack of data on whether
• 29:21we should be using this technique
• 29:23for Bethesda three and four,
• 29:26so currently not recommended and
• 29:28this is to be determined.
• 29:31Briefly, just wanted to show
• 29:33you a little graph of how five
• 29:36year followup of 84 low risk.
• 29:38Micro papillary thyroid carcinoma
• 29:41had achieved 100%.
• 29:44Regression over five years and
• 29:46this is just showing that there's
• 29:50no neoplastic change secondary to
• 29:53radiofrequency ablation of thyroid nodule.
• 29:57It's mostly just a spin.
• 30:00Ion cellular change.
• 30:01And because RFA does not alter the
• 30:04thyroid capsule or cause neoplastic change,
• 30:08it is.
• 30:09OK to redeploy RFA if needed or have
• 30:13the patient undergo a surgery if needed.
• 30:18So I'm going to just wrap up my talk
• 30:21by saying that RFA availability an
• 30:24indications will continue to evolve,
• 30:27and I think this is not a fad,
• 30:30but this is a treatment method that
• 30:33will probably stay and management
• 30:35decision really should involve
• 30:37multidisciplinary team of experts and
• 30:40include the patient in the decision making.
• 30:43And I think this technique,
• 30:45given that it's relatively new to the US.
• 30:49May involve specialists from the
• 30:53Interventional radiology surgery in
• 30:55endocrinology and multiple host of pathology,
• 30:58etc.
• 30:59It is fitting for us to be
• 31:03introducing this technique.
• 31:06As Smilow and I am a strong
• 31:09proponent of inviting the patient
• 31:12into making what is best for them,
• 31:16so it is important for us clinicians
• 31:19to not introduce our own clinician
• 31:22bias just because I'm a surgeon,
• 31:25I'm not going to advocate a surgery.
• 31:29Ann,
• 31:30this is not a technique that I
• 31:33currently subscribe to 100%,
• 31:34but I do believe that it has
• 31:37a role and I'll be.
• 31:40I'll do my best to be impartial and
• 31:44introduced this technique to Yale,
• 31:46so more research obviously is needed
• 31:50and we are actively doing project
• 31:53looking at our own institutional data.
• 31:57So I'm just going to wrap up by
• 31:59showing you this quote by Hippocrates,
• 32:01those diseases that medicines do
• 32:03not cure or cure by the knife,
• 32:06those that the knife does not
• 32:08cure or cure by fire,
• 32:09those that fire does not cure
• 32:12it must be incurable.
• 32:13But this.
• 32:16Philosopher also said first do no harm,
• 32:19so it is really a responsibility,
• 32:21and it's imperative that we
• 32:24deploy this technique safely.
• 32:26And I'll take any questions and
• 32:28thank you for your attention.
• 32:31Or Grace, thank you.
• 32:32That was a really terrific summary
• 32:34and it's really wonderful that you're
• 32:37bringing this technology and technique
• 32:39to bear for our patients at Yale.
• 32:41Just because we're running a little late.
• 32:43I'm gonna. I'm going to suggest that
• 32:46anyone has questions should probably
• 32:48reach out to grace directly and and turn
• 32:51now to our next speaker. And really,
• 32:53our next speaker needs no introduction.
• 32:55Doctor hyphen Lin Lin, as you know,
• 32:58is the Eugene Higgins Professor of
• 33:00cell biology, professor of genetics.
• 33:02Obstetrics, gynecology,
• 33:03and Reproductive Sciences and he is the
• 33:05director of the Yale Stem Cell Center.
• 33:08His work since joining Yellen 06
• 33:10to launch the center has really
• 33:12taken this center to national
• 33:15and international prominence,
• 33:16his own work focusing on self renewing
• 33:19mechanisms of stem cells is really informed
• 33:21cell biology and cancer in multiple ways,
• 33:24and I think he's going to share
• 33:27with us the work that he's done in
• 33:30terms of a gene family that.
• 33:32He and his lab have discovered
• 33:34and its relevance to cancer,
• 33:35so hyphen thank you very
• 33:37much for speaking today.
• 33:39Well, thank you much Charlie
• 33:40for a very kind introduction.
• 33:42I'm delighted to have this opportunity
• 33:44to give a progress report on my own to my
• 33:48own colleagues and your Cancer Center.
• 33:50Although I've worked for many years
• 33:52on stem cells and developmental
• 33:54biology regarding Cancer Research,
• 33:56I'm completed a new kid on the block.
• 33:59So in the past few years or research
• 34:02on gene regulation or stem cells,
• 34:04let us to the cancer field.
• 34:06So today, instead of talking about
• 34:08my usual type of stem cell research,
• 34:11I'm actually going to share with
• 34:14you some preliminary results
• 34:15of our recent cancer work.
• 34:17And this actually is my first
• 34:19time talking about these results.
• 34:21I hope to get your expert input
• 34:24advice and potential collaboration.
• 34:26So to begin, let me share my.
• 34:31Slice
• 34:36screen sharing.
• 34:43OK can you see my slides?
• 34:45Yes OK, great wonderful yeah.
• 34:48So you know as Charlie mentioned.
• 34:51I will first give a bit background
• 34:54about some of our earlier work to
• 34:57pave the way for my cancer results.
• 35:01So in 2000.
• 35:041998 we discovered the Argonauts gene
• 35:07family as the first in family that's
• 35:10highly conserved during evolution.
• 35:13For its stem cell function and this Infirmary
• 35:16encodes a highly conserved group of proteins,
• 35:21called argument proteins that
• 35:23contains 4 functional domains,
• 35:25among them the PhD domain.
• 35:27Mydomain mines too small Agnes whereas
• 35:31period of mine actually resembles SH.
• 35:34And this gene or protein family
• 35:37has been subdivided into two
• 35:39subfamilies and you probably know
• 35:41very well about Argonaut subfamily.
• 35:44Which plays a central role in
• 35:46the micro angle and the angle
• 35:48iron mechanism and these proteins
• 35:51directly bind to sin is micro honest,
• 35:54which are in general 21 nucleotides long.
• 35:58And Becausw are gonna suffer.
• 35:59My proteins are expressed in
• 36:01most type of sales.
• 36:02That's why I mean I mechanism and
• 36:05microrna regulation works for all of us
• 36:07who are doing this type of experiments.
• 36:10However,
• 36:10I said stem cell person I was more
• 36:13interested in the other sub family.
• 36:15The piece of family cause it's
• 36:17mostly expressed in the German in
• 36:20the most primitive stem cells.
• 36:22So in 2006 my lap and almost simultaneously
• 36:26three other labs discovered that the
• 36:29piwi subfamily proteins bind to yet
• 36:32another class of non small coding,
• 36:35honest that we named Piwi
• 36:38interacting organisms.
• 36:39Or paying it for short so paying
• 36:42is just like PV proteins.
• 36:44They're mostly expressing that you're mine,
• 36:46and they're somewhat longer
• 36:48than Micro RNAs or Sir is.
• 36:51So in this slide,
• 36:52just just wanna share with you
• 36:54some salient features of Python
• 36:56is versus Micron is,
• 36:58which are better known in
• 36:59addition to being a bit longer,
• 37:02pang is a very complex,
• 37:03so in my lab we they have cloned
• 37:06over 16 Millions of these pioneers,
• 37:09which is in sharp contrast to
• 37:11the 1000 species or Micron is
• 37:13that's known in any Organism.
• 37:15And in addition, the pairing is target.
• 37:18All type of Genomic sequences,
• 37:21again in sharp contrast to microarrays,
• 37:23which mostly target the three point
• 37:26you TR or mature Messenger RNA is.
• 37:30And finally,
• 37:31the Biogenesis is very different.
• 37:33Hanges are mostly produced from
• 37:35long single stranded RNA's in
• 37:36conscious to Micro Arnie's feature.
• 37:39From here penari precursors.
• 37:42So this discovery is very interesting
• 37:44to us because as you all know
• 37:47that the molecule biology field
• 37:48relies on very important principle
• 37:51called the central dogma.
• 37:53Which tells us that genetic
• 37:55information in DNA is transcribed
• 37:57into Messenger RNA's and then
• 37:59further translated into proteins.
• 38:01And that's how life process starts.
• 38:04The discovery of Micro Arnesen small
• 38:07Angus like S Ion is further enriched
• 38:10this dogma by telling us that now
• 38:13there are two new mechanisms regulating
• 38:16the stability or the translational
• 38:19efficiency of micro earnings.
• 38:21However,
• 38:22when we looked into where these genes
• 38:25encoding pioneers reside in the genome,
• 38:27it to our big surprise they do not reside
• 38:31in this known gene coding region which
• 38:34only represents 1 to 2% of a genome.
• 38:38Instead, they mostly result in this
• 38:41junk DNA we call useful junk represent
• 38:44the vast majority of what you know.
• 38:47And it is those genes they produce
• 38:51these enormous number of Pioneers.
• 38:54So we were you following about
• 38:57this discovery, because if you
• 38:58likens our genome as the world,
• 39:00then the traditional jeans
• 39:02are like the Old World, The.
• 39:05Asia, Europe, continent.
• 39:06And somehow our research let us lend
• 39:10it to assure of a computer New World.
• 39:13We spy on agents now many other genes.
• 39:16So this actually was a pie I baked for my
• 39:20lab to celebrate the discovery of honey,
• 39:24and it's my first breaking product.
• 39:26And also this discovery was
• 39:28selected by science as one of
• 39:31the 10 breakthroughs in 2006.
• 39:33The only biology breakthrough
• 39:35that was selected.
• 39:37So, this excitement aside,
• 39:39the key question really is.
• 39:42Does any of these peyronies
• 39:44have any functions?
• 39:45So in past several years my lap is in
• 39:48focusing on these pioneers functions.
• 39:51It turns out these pioneers
• 39:53and their partner PV proteins.
• 39:55They can be present sometimes in the
• 39:58nucleus and sometimes in the cytoplasm.
• 40:00So we wanted to 1st know when these
• 40:04peripatric complexes in the nucleus.
• 40:05What's their function?
• 40:08To address the question,
• 40:10I'd like to bring your attention
• 40:12to a field called epigenetics.
• 40:14You probably know that epigenetic is
• 40:17a very exciting field that started
• 40:19gene regulation and the focus or
• 40:21current epigenetic studies focus on
• 40:24identifying epigenetic factors and
• 40:26illustrating how they modify the
• 40:28histone ordinate modification status.
• 40:29Therefore,
• 40:30turning on and off the expression of genes.
• 40:34However, to me this epigenetic
• 40:36factors there are so called down molecules.
• 40:39They mostly don't bind DNA,
• 40:41let alone recognize specific DNA sequences,
• 40:44but somehow they had to be guided
• 40:47precisely to specific genes in the genome.
• 40:49For example here,
• 40:51but not here or here.
• 40:53In order for epigenetic programming to work,
• 40:55and for the life process to unfold.
• 40:59So to me ascential question in genetics
• 41:01is what are the mechanisms inside the
• 41:04nucleus that can guide these enzymes to
• 41:07the right sites in the genome at the
• 41:09right time in the right type of cells?
• 41:13When we started our work a few
• 41:16epigenetic factors were illustrated
• 41:17to be guided by a few transcriptional
• 41:21factors to the promoters of a few genes.
• 41:24And that was exciting by small an exception.
• 41:27Becausw for soil represents
• 41:29a feedback mechanism,
• 41:30and Secondly,
• 41:31it was only accountable for very
• 41:34small number of genes in Arduino.
• 41:36So the big question to me existed and
• 41:39still in a way exist is that what's the
• 41:42mechanism that guides these epigenetic
• 41:45factors to their target sites?
• 41:47So,
• 41:48Fast forward to today after
• 41:50several years old research,
• 41:51we discovered that the PV panel
• 41:54complex it should play a central role,
• 41:56at least in the June sales to guide the
• 42:00epigenetic factors to their target sites.
• 42:03So this is how it works.
• 42:05So the peewee protein and its partner
• 42:07apparently will form a complex.
• 42:09And this complex will bind to Genomic
• 42:13sequences with complementary sequences.
• 42:15Actually, by binding to Nathan RNA
• 42:19That's tethered still to the genome.
• 42:23This then leads to the
• 42:25recruitment of this complex.
• 42:27Two other epigenetic factors,
• 42:29such as histone here to competent protein,
• 42:33one to this site,
• 42:35which initiated a bit genetic programming
• 42:37and this complex will further recruit
• 42:40other epigenetic factors such as
• 42:43Houston Metro transfers to the site,
• 42:46which further then further
• 42:48elaborate epigenetic programming
• 42:49by methylate in this case,
• 42:51Houston H3K9 Residue.
• 42:53So this is what we initially
• 42:56discovered into software and now
• 42:59in human and mammalian systems we
• 43:02found that this complex can also
• 43:05recruit DNA methods to the target
• 43:08size to achieve demethylation.
• 43:11So I'm happy to report that you know,
• 43:14up to now epigenetics study allowed
• 43:16us to discover a major mechanism
• 43:18in the germline cells that will
• 43:20recruit epigenetic factors.
• 43:22Too many sites in the genome to
• 43:25achieve epigenetic programming.
• 43:26And as you all know,
• 43:28such programming is very important
• 43:30for stem cell self renewal for
• 43:33German development for transposon
• 43:35silencing and so on.
• 43:37So then you might wonder
• 43:39what's the function of this P.
• 43:41We empowering molecules when
• 43:43they're in the cytoplasm.
• 43:45So again,
• 43:46just to briefly review what we
• 43:48found in the past few years,
• 43:50we found that they actually play a
• 43:53very important role in mediating the
• 43:56regulation of transposons and pseudo genes.
• 43:59Thoards protein coding genes.
• 44:01You all know that transposons
• 44:04are viewed as selfish parasites.
• 44:07That invaded our genome and
• 44:09traditionally and still today.
• 44:11Many textbooks regarding.
• 44:14Self is the element without any
• 44:16active function except for potential
• 44:18advantage during evolution.
• 44:20Pseudogenes are viewed as the
• 44:22default caucus of our active genes
• 44:24on their way out during evolution,
• 44:27but we found that transposons,
• 44:29pseudogenes actually play a very
• 44:31important role in regulating the
• 44:33regular protein coding genes
• 44:35that we know very well,
• 44:37and this regulation actually is
• 44:39mediated by the preparing complex.
• 44:41So, back to the central dogma, again, DNA.
• 44:44For protein coding,
• 44:46gene is transcribed into a pre
• 44:48Messenger RNA which is then.
• 44:50Kept tailed and the entrance prized
• 44:53become a mature Messenger RNA.
• 44:55It got exported into the cytoplasm.
• 44:59About two years ago,
• 45:00we discovered that about 50%
• 45:02of genes in human genome.
• 45:04It should contain transposon
• 45:06sequences in the three point beauty,
• 45:08our or their Messenger on is.
• 45:11That was very surprising finding to us
• 45:14and after that we found that actually,
• 45:17transposons actually actually
• 45:18expressed a low level,
• 45:20at least in germ cells and primitive
• 45:22and some primitive stem cells,
• 45:25and the transposon expressed transcript
• 45:27will be processed into mature.
• 45:29Long is and bound by peewee proteins too.
• 45:33From this peripera complexes.
• 45:35These complexes can then,
• 45:38as you can imagine,
• 45:40beautifully target their corresponding
• 45:42or complementary transposon sequences.
• 45:44That's hiding in the three point
• 45:47beauty of material Messenger
• 45:49is to regulate the expression
• 45:51of this Messenger RNA.
• 45:53In addition, we found that the so called
• 45:55the so called that you know pseudogenes,
• 45:57that that copies of our active
• 45:59genes are actually not quite dead.
• 46:01They also have a very important role.
• 46:03They are often expressed into
• 46:05Messenger on is in antisense,
• 46:08and those antisense Messenger honest
• 46:10will be processed by TV proteins.
• 46:13To become pioneers again and
• 46:15form complex with PV protein.
• 46:17And as you can imagine,
• 46:19this antisense RNA will be very
• 46:22capable or targeting the cognitive
• 46:24active genes of the sudo gene.
• 46:27So now we know the gene regulation actually
• 46:29is not a linear way like what's stated
• 46:32by central dogma is very complicated,
• 46:34and Pironi Imperial proteins
• 46:36play essential role there.
• 46:38Likewise, if you are aware of new discoveries
• 46:41on some other non coding on is such as long,
• 46:45noncoding,
• 46:45honest or called Lincoln for short,
• 46:48even the expression of these thousands
• 46:51of Lincoln is regulated by Python is.
• 46:54And this regulation
• 46:56originates from transposons.
• 46:57Because we found that many linkon is
• 47:00again content transporting sequences.
• 47:03So these sequences,
• 47:04like Trojans horse inside their
• 47:07enemies and the transposon.
• 47:10Derived piony,
• 47:11we're together with people holding
• 47:13bind to these target armies and
• 47:15regulate this target armies.
• 47:17So, just to summarize this part of my
• 47:20talk as a background for the cancer site.
• 47:23Again, if you like his argeneau as the world,
• 47:27then the traditional jeans that
• 47:29we studied most of the time.
• 47:32About 23 thousand of them apart of
• 47:34the small world at the Old World,
• 47:37and even in the Old World we often
• 47:40forget the presence of pseudogenes.
• 47:43In human there are over 14,000 pseudogenes,
• 47:46and the transposons over a million,
• 47:49so transposons.
• 47:50And apparently work.
• 47:51Let us landed ashore of a new world.
• 47:54Now the New World also contained
• 47:56another big class of non coding
• 47:59on is called Inca armies.
• 48:00Implying is actually serve a very important
• 48:03function to connect these two words.
• 48:06I've shown you very quickly in the
• 48:08Schematic Summary Paris can regulate
• 48:10the expression of traditional jeans.
• 48:13Panic and regulate expression of
• 48:15Lincoln engines powering it can
• 48:17regulate the expression of traditional
• 48:19jeans through information from
• 48:21transposon and even pseudo genes.
• 48:23Can you spy on its pathway to regulate the
• 48:27expression of the cognat active genes?
• 48:30So now for this audience you might
• 48:33be very curious about does any of
• 48:35these basic discoveries have anything
• 48:37to do with the clinical side?
• 48:40We reasoned that because all these jeans
• 48:42are so important for stem cell division,
• 48:45if you delete any of these genes,
• 48:47stem cell with differential
• 48:48into ordinary cell,
• 48:49we wondered if we overexpress
• 48:51these jeans wear that cause
• 48:53malignant professional stem cells.
• 48:55And will there be possibly A cause of cancer?
• 48:58So the question we really ask is is
• 49:00preparing a function related to cancer.
• 49:03So a number of years ago we took
• 49:06some human seminoma cancer patients.
• 49:10Their testicular samples versus
• 49:12testicular samples from normal males
• 49:15and other kinds of testicular cancers
• 49:18derived from non stem cell based malignancy.
• 49:21And we found that a human gene that
• 49:25we named he means human pee wee is
• 49:30just the overexpressed in seminoma.
• 49:33Which is known to be a stem
• 49:35cell derived testicular cancer.
• 49:37This in fact was the first thing to show such
• 49:40a high correlation to this type of cancer,
• 49:44so encouraged by that in the past few years,
• 49:47we decided to look into other forms of
• 49:50cancer to see if any of these P regions
• 49:53are over expressed in these cancers and
• 49:56we first took M at the breast cancer,
• 49:59especially triple negative breast cancer.
• 50:00For reasons you all know.
• 50:02And we first screened through six most
• 50:05representative lines of human breast cancer,
• 50:08and this is the normal human breasts tissue.
• 50:12And this is the mouse one.
• 50:15And we looked for the expression of peewee
• 50:18proteins or genes in this cancer tissues.
• 50:22There are four human genes
• 50:24encoding period proteins.
• 50:25They're called peewee like 123 and four.
• 50:29And we found out all four
• 50:32overexpressed and especially IPV 4.
• 50:34In all six breast cancer cell
• 50:37lines before becomes detectable,
• 50:39expressed and in five out of 6 lines period.
• 50:424 become expressed at least 50 times
• 50:46higher than what's in the normal tissue.
• 50:49So encouraged by this cell line based study,
• 50:53we decided to approach patients
• 50:56directly and we randomly sampled 20
• 50:59breast cancer patients for the appeal
• 51:01wise tissue between the Nonmalignant
• 51:04was tissue versus their own molecular
• 51:07breast tissue and to our delight,
• 51:09we saw that 10 out of 20 patients
• 51:13indeed showed version overexpression
• 51:16of the provisions.
• 51:18And to further confirm this correlation
• 51:20we went to NCI database and two screens
• 51:24through over 1000 cancer patients whose
• 51:26period expression pattern was known.
• 51:29And indeed we found that for those cancer
• 51:32patients with higher level or PV four
• 51:36expression there much worse prognosis.
• 51:38So based on this very solid correlation,
• 51:41then we wanted to know what's
• 51:43the role of PV 4IN.
• 51:44Breast cancer.
• 51:45Is this just a passive consequence of cancer
• 51:48development or it could be an active role in
• 51:51promoting cancer formation and development?
• 51:53So in that, to address the question,
• 51:56we first did the cell based experiment.
• 51:59This you probably a very familiar is the
• 52:02triple negative breast cancer cell line.
• 52:05Highly aggressive.
• 52:06When we did the wound healing assay.
• 52:09Normally if you remove this part of the
• 52:12breast cancer cells just within 36 hours,
• 52:15the residual cells will highly proliferate,
• 52:18highly proliferative and migrate into
• 52:20the central region to see all the void.
• 52:24However, if you just need to knock
• 52:27down the expression of P V4, then.
• 52:29For long time,
• 52:31much beyond actually 36 hours,
• 52:33these cancer cells fail to proliferate
• 52:35at high speed and they fail to migrate.
• 52:38And we've,
• 52:39you know,
• 52:40confirm this asset by chance
• 52:42will essay also indicate that
• 52:44PVL for knockdown affects cancer
• 52:47cell proliferation and migration?
• 52:49Then we wondered through what kind
• 52:52of molecular mechanism period 4
• 52:54achieve such a amazing function.
• 52:57And it turns out TV four is very important.
• 53:01In promoting the epithelial tamanika,
• 53:04more transition of this breast cancer cells.
• 53:08Because when we reduce the PV four expression
• 53:10in this triple negative cancer cells.
• 53:13Actually, that alone can revert
• 53:15this cell fate for mesenchyme all
• 53:18state back to epithelial state.
• 53:20So Soon as example here,
• 53:22ecad hearing is a typical epithelial
• 53:25marker and incoherent is Amazon Co
• 53:28marker and this is a loading control.
• 53:31The regular,
• 53:32a triple negative breast cancer cells
• 53:34are competing between carmalized.
• 53:36This express very high level,
• 53:39incoherent, but no expressional.
• 53:41Equal hearing is detectable now if
• 53:44we just knock down PV L4 to 70% or
• 53:47be higher efficiency and the three
• 53:50independent markdown conditions.
• 53:52Desales, I guess you know,
• 53:53revert back to the procedure failed.
• 53:56So that was very exciting to us
• 53:57because very few in the cancer
• 53:59literature as you know better than me,
• 54:01people can see that kind of Revolution.
• 54:03Then we say,
• 54:04why is peewee so important in controlling
• 54:07the wholesale faith transformation?
• 54:09And we looked into the molecular
• 54:11pathway to not pee wee.
• 54:13Four promotes the TGF beta and FDF data
• 54:16signaling pathways in cancer cells.
• 54:18So these signaling pathways are all
• 54:20highly expressed in breast cancer cells.
• 54:23But you knock down peewee expression.
• 54:25The expression is just a compromised.
• 54:29In addition to this,
• 54:30we were surprised to find that three or
• 54:34four also inhibit the expression of MHC
• 54:37two complex components in cancer cells.
• 54:40So this analysis allowed us to
• 54:43propose a model that actually PL-4
• 54:46is a very assume key regulator
• 54:49that promotes breast cancer.
• 54:51Uncle Genesis,
• 54:52it does so by promoting these typical
• 54:55and Progenics signaling pathways.
• 54:58Activities within promotes
• 55:00the cancer cell survival,
• 55:02increase their proliferation and.
• 55:04Cause them to have EMT.
• 55:07Meanwhile,
• 55:08the pee wee molecule will suppress
• 55:10the host immune system surveillance
• 55:13allow these cancer cells to
• 55:15escape the immune surveillance.
• 55:17So this was the first somatic
• 55:20and major cancer type that we
• 55:22looked encouraged by that.
• 55:23We wondered whether any other piwi protein
• 55:26expression is correlated and possibly
• 55:28A cause of other major type of cancers.
• 55:31Then we looked into a second
• 55:33major type of somatic cancers,
• 55:35namely gastric cancers.
• 55:37And here, as you can see,
• 55:39you probably are very
• 55:40familiar with this Histology.
• 55:42In the.
• 55:43Left panel this is just a chemical
• 55:46standing with another PV protein
• 55:49called PV L1 now standing Brown.
• 55:52You see,
• 55:53in this adenocarcinoma sections
• 55:55from either the gastric body or the
• 55:58gastric cardia or the gastric trap.
• 56:01And in turn regions.
• 56:03There are robust overexpression of PL-1.
• 56:07And in chronic gastritis,
• 56:09which is a milder form pre cancer condition,
• 56:12you see also a topic expression of PDL one,
• 56:16but at much lower level.
• 56:18P1L1 expression is not there
• 56:21in the normal gastric tissues.
• 56:23When we quantify that this expression
• 56:26level is nicely correlates to the
• 56:29advancement of the gastric cancer
• 56:31stages from stage one to four,
• 56:33you see increased expression of
• 56:35period one and also nicely correlate
• 56:38with the distant metastatic
• 56:39ability of these cancer cells.
• 56:42For you know not to not to
• 56:45multiple distant, not you see.
• 56:47Again these cells show higher level
• 56:49PV one expression and Interestingly
• 56:52its expression level is inversely
• 56:55correlated to the Differentiation State
• 56:57of these cancer tissues or cells.
• 57:00So based on that, we decided that
• 57:03the PO1 must likely also play a role
• 57:06in promoting gastric cancer and two.
• 57:09A test that question in also in
• 57:12addition to the cell biology and cell
• 57:16based assets as I showed you earlier,
• 57:19we also did the cancelled
• 57:22Genographic transform essay.
• 57:23So when we transplant these gastric
• 57:26cancer cells into nude mice.
• 57:29It growth, robust tumors,
• 57:31and if you introduce the
• 57:33negative control for knockdown,
• 57:35it does not affect tumor growth.
• 57:37However, if you introduce S Ioni,
• 57:40the specific knockdown,
• 57:42the expression of P V1.
• 57:44In this cancer tissues,
• 57:46you just reduce the tumor formation
• 57:49and when you looked into these
• 57:52two more tissue sections by,
• 57:54for example,
• 57:55the cell proliferation markers such as PCA,
• 57:58that's indicating Brown here or Ki 67
• 58:01you see in the wild type situation.
• 58:06The cells are highly mitotic and prolific.
• 58:09In the controller down you don't
• 58:12see any big difference.
• 58:14But in the period one knockdown
• 58:16you greatly reduced.
• 58:18The proliferation of these cells and
• 58:20that's a duplicate sure is the same thing.
• 58:24So based on that?
• 58:26You know we wanted to know.
• 58:29Weather Pang is appeared role in this period.
• 58:32Proteins function in cancers.
• 58:34We expected to see pioneers and
• 58:36cancer specific powers to show up,
• 58:38but to our surprise,
• 58:39when we did deep sequencing for the
• 58:42small non coding RNA population,
• 58:44we could not detect any pianese we detected
• 58:47lots of micro honest which is normally
• 58:49a smaller population than pioneers.
• 58:52But now even with this big presence
• 58:55of microrna population we cannot see
• 58:57any or if any just very few pennies.
• 59:01That's where a matching to the high
• 59:03level of heavy protein expression
• 59:05and let us too.
• 59:06Conclude or to hypothesize that
• 59:09piwi proteins function in cancer
• 59:12might be independent of Pianese.
• 59:15To really demonstrate that's the case,
• 59:18we generated this mutant PV proteins
• 59:20by mutating three of its residue
• 59:23in the PV domain that you might
• 59:26remember from my introductory slides.
• 59:29That's possessing the only cleavage
• 59:32activity and pioneer binding activity so.
• 59:35When you mutate these three residues,
• 59:37the resulting engineered mutant
• 59:39protein can no longer bind to pioneer.
• 59:41Then we wanted to see if this.
• 59:44Pilot Binding Deficient Mutant Perior
• 59:47one proteins are still oncogenic
• 59:49and turn out that's the case.
• 59:51So normally in these gastric cancer cells,
• 59:55if you do transfer your essay
• 59:58for their migratory ability.
• 01:00:00Highly migratory.
• 01:00:01Now if you knock down the P1 is question,
• 01:00:07you greatly reduced its migratory ability.
• 01:00:11But if you in this knockdown cell
• 01:00:13now reintroduce into these cells,
• 01:00:15that mutant PV protein that
• 01:00:16cannot bind to pay on it,
• 01:00:18but that's alone is sufficient.
• 01:00:21To restore the majority
• 01:00:22ability of these cells,
• 01:00:24so this analysis tells us
• 01:00:26that this pee wee function
• 01:00:28in gastric cancer,
• 01:00:29at least in gastric cancer,
• 01:00:32is actually very independent.
• 01:00:34So our latest results showed that
• 01:00:37pee wee actually in gastric cancer
• 01:00:39they do not interact with piramis,
• 01:00:42but they interact with the nonsense mediated
• 01:00:46decay immediate regulatory mechanism.
• 01:00:48An empty to regulate the cancer genome
• 01:00:51or cancer transcript on what we think
• 01:00:54what's happening is that the piwi protein,
• 01:00:57when it's highly expressed
• 01:00:59in these cancer cells.
• 01:01:01It directly target tumor suppressor cells,
• 01:01:03army and degree design is so that
• 01:01:05allowed the uncle genic alarm is
• 01:01:08to promote her ankle Genesis.
• 01:01:10And Meanwhile as you know,
• 01:01:12some tumor suppressor anger is
• 01:01:13themselves with directly supports.
• 01:01:15Cancer grows in the squashing function is
• 01:01:18not knock down because of PV overexpression.
• 01:01:21So we're very excited
• 01:01:23about these discoveries.
• 01:01:24In fact,
• 01:01:25this discovery started from to
• 01:01:27Safra and now we can always see the
• 01:01:30hope of approaching clinical site.
• 01:01:33Of course,
• 01:01:33I wanted to know whether you know
• 01:01:36we can use this as a therapeutic
• 01:01:39target and we have some preliminary
• 01:01:41results show that's quite possible.
• 01:01:44So shown here is a new method
• 01:01:47that's being developed in my lab.
• 01:01:50Is nanoparticles loaded with?
• 01:01:51This song is against these proteins.
• 01:01:54In this case,
• 01:01:55it's against another under binding
• 01:01:57protein called familiar that we
• 01:01:59also worked on and has also has a
• 01:02:01tumor function promoting function.
• 01:02:03You can inject these.
• 01:02:06Nanoparticles through Kelvin into
• 01:02:08the mice that contains human cancer.
• 01:02:11In this case, colorectal cancer graph.
• 01:02:15And 28 days after that.
• 01:02:18After they closed due to the injection
• 01:02:20and after four times or injection
• 01:02:23then you use city to visualize
• 01:02:25the tumor growth and the web micro
• 01:02:27angle is and sin is localized.
• 01:02:29So we label this as an every
• 01:02:32sci-fi and tumor with luciferase,
• 01:02:35so by city image Ng just 4024
• 01:02:37hours after the first injection.
• 01:02:40You can see these nanoparticles become
• 01:02:43highly enriched in the tumor cells.
• 01:02:46And then if you let these mice continue
• 01:02:49to grow and you can see normally.
• 01:02:53If you just in the ceiling
• 01:02:55control or randomize this,
• 01:02:57I only control this grafted tumor tissue.
• 01:03:00Grow quite robust in this new mice and
• 01:03:03also will start to undergo metastasis.
• 01:03:06See other spots within 28 days.
• 01:03:09But if you do tell,
• 01:03:11then injection of these nanoparticles
• 01:03:14loaded with anti this particular
• 01:03:16proteins are as I only you can
• 01:03:18really control the tumor growth.
• 01:03:20So you know,
• 01:03:22we really feel like basic research
• 01:03:24allows us to potentially found the
• 01:03:27computer novel oncogenic mechanism.
• 01:03:28That's not specific to a particular
• 01:03:31type of cancer,
• 01:03:32but probably is to multiple type of cancers.
• 01:03:36Through our own data,
• 01:03:38we've shown that in breast cancer,
• 01:03:40in gastric cancer.
• 01:03:42In seminoma and in prostate cancer.
• 01:03:44In skin cancer,
• 01:03:46in liver cancer and in colorectal cancer.
• 01:03:49At least subtypes of these cancers.
• 01:03:52They have high level of period
• 01:03:54overexpression and period appeared to be
• 01:03:57a driving mechanism for this type of cancers.
• 01:03:59So my stream is to use these
• 01:04:02TV proteins as target.
• 01:04:04To treat cancer,
• 01:04:05to develop new treatment for cancer becausw
• 01:04:08PV proteins. As I mentioned earlier,
• 01:04:10there only needed in the germline
• 01:04:13and come to adult states.
• 01:04:14They only needed in the male germ
• 01:04:17line because female germline,
• 01:04:19namely over does not have stem cells.
• 01:04:22Only spermatogonia stem cells active here.
• 01:04:24So basically you can completely
• 01:04:26knockout these proteins.
• 01:04:27The normal self development
• 01:04:29will not be affected.
• 01:04:30We've done so now called
• 01:04:32entire period family in mice,
• 01:04:34mice happily surviving.
• 01:04:35The only problem is the male
• 01:04:38mice and we predict them.
• 01:04:39Male patient in human,
• 01:04:41they will temporary loss fertility but
• 01:04:44that easily can be solved by stores
• 01:04:46and sperm right before the treatment.
• 01:04:49So this is my dream and I hope you
• 01:04:52know with potential collaboration
• 01:04:54with all of you in the future
• 01:04:57or some of you we can take,
• 01:05:00you know steps forwards and hopefully
• 01:05:03there will be a 2 new cancer.
• 01:05:06Treatment message will emerge from this,
• 01:05:08so I'd like to thank my lab
• 01:05:11members who did work and since
• 01:05:13I'm running over our stuff here.
• 01:05:17Hyphen that was fabulous body of work.
• 01:05:19And congratulations on all of it.
• 01:05:22And really, as you point out,
• 01:05:24it really does Availa bold new
• 01:05:27approach of cancer therapy.
• 01:05:28I know we're essentially out of time,
• 01:05:31but let me just ask one question beyond
• 01:05:35potentially targeting through SI RNA,
• 01:05:37are there other potential
• 01:05:38approaches to target these genes
• 01:05:40in terms of future Therapeutics?
• 01:05:42No, that's
• 01:05:43a very good question into it.
• 01:05:46The answer is yes.
• 01:05:47Because these proteins,
• 01:05:49not the atomic structure,
• 01:05:50have been resolved, so we know exactly
• 01:05:53how the active side looks like.
• 01:05:56And so we're also starting to
• 01:05:58use a small molecule based
• 01:06:01screen to find these mimics.
• 01:06:03Of this active site binding substrate,
• 01:06:05and hopefully those will be specific to
• 01:06:08target and knock down these molecules
• 01:06:10too well. That's exciting,
• 01:06:11and it sounds like a potentially
• 01:06:14new area for Therapeutics.
• 01:06:15Well, I know we're out of time.
• 01:06:18I want to thank those who joined
• 01:06:20us and thank hyphen and Grace
• 01:06:22for two really superb talks.
• 01:06:24Great work and thank you everyone
• 01:06:27and enjoy the rest of your day.
• 01:06:29Well, thank
• 01:06:30you very much for your
• 01:06:32invitation. Bye bye bye bye.