Pathology Grand Rounds, Sept. 18, 2025 - Joshua Warrick, MD
February 20, 2026Pathology Grand Rounds, Sept. 18, 2025, Joshua Warrick, MD, professor of pathology, director, genitourinary pathology, Yale School of Medicine.
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- 00:02Good afternoon. Welcome to pathology
- 00:05ground runs.
- 00:06And,
- 00:08we have today's speaker, doctor
- 00:11Joshua
- 00:12Warwick.
- 00:14And,
- 00:15doctor Warwick graduated from
- 00:19the, West Wayne State University
- 00:21for her medical educations.
- 00:24After that, he he did
- 00:25his residency
- 00:27at initially, actually, it's a
- 00:29Lou,
- 00:32Saint Louis or Saint Louis
- 00:34University, Saint Litton,
- 00:36WashU,
- 00:37and complete his residency. And
- 00:39then which is followed by
- 00:41the fellowship training in Geo
- 00:43Passage
- 00:44as well as surgical massage
- 00:47at University of Michigan.
- 00:49So,
- 00:51he joined,
- 00:53Pennsylvania
- 00:54State University
- 00:56and, starting his career and,
- 00:58risk his ranking
- 01:00for initial assistant professor
- 01:02to full professor.
- 01:04So he,
- 01:06was the
- 01:08vice chair for clinical operation
- 01:12and director of
- 01:14the anatomic massage
- 01:16and also director of the
- 01:18GU Pathology Services
- 01:20there.
- 01:21We're fortunate
- 01:22to have him,
- 01:24you know, join the Yale
- 01:26and he just started his
- 01:27faculty
- 01:29here as director of the
- 01:31GU Passage.
- 01:32So
- 01:34Dodd Warrick did extensive
- 01:37research on
- 01:38the bladder cancers.
- 01:40His research funding was,
- 01:42supported by the NIH
- 01:45and cancer
- 01:46American Cancer Society and also
- 01:49DODs.
- 01:51He,
- 01:53has been invited to give
- 01:54many talks
- 01:56and, at national and international,
- 02:00conference.
- 02:01He path bridge extensively
- 02:03and has more than around
- 02:05the one hundred publications
- 02:08and peer reviewed,
- 02:10journal articles,
- 02:11book chapters.
- 02:13And,
- 02:14so today he gonna share
- 02:16his experience
- 02:17in the breast cancer with
- 02:19us. His topic the the
- 02:22title of his talk is
- 02:23the lineage praxisity
- 02:24of the blood cancer.
- 02:26So without further ado, I
- 02:28will hand over to doctor
- 02:30Warrick. Thank you.
- 02:35Okay. Thank you, Doctor. Kai.
- 02:39So, yeah, so we're going
- 02:39to talk about bladder cancer.
- 02:42So I have I have
- 02:43no conflicts of interest right
- 02:44now.
- 02:48So there's there's two themes
- 02:49to the talk today.
- 02:50The first is gonna be
- 02:51that, bladder cancer demonstrates remarkable
- 02:54lineage plasticity,
- 02:55even without selective pressure from
- 02:57treatment. A lot of cancer
- 02:58types, you know, lung cancer,
- 03:00prostate cancer, they undergo lineage
- 03:02plasticity, but they generally require
- 03:03treatment pressure like prostate cancer
- 03:04and androgen deprivation therapy. Whereas
- 03:06bladder cancer is just plastic.
- 03:08It just does it on
- 03:09its own.
- 03:11And this is key, in
- 03:12in part driven by key
- 03:14transcription factors and interferon gamma
- 03:16signal.
- 03:17So these two statements are
- 03:18are gonna really, you know,
- 03:19like, be the frame from
- 03:20which
- 03:21yeah.
- 03:21So these are the these
- 03:23will be the the ideas
- 03:24that we frame the entire,
- 03:25talk through.
- 03:29Can you guys see the
- 03:30mouse? Good.
- 03:31So
- 03:32transcription factors, like so what
- 03:34are transcription factors? Let's all
- 03:35get on the same page
- 03:36here. So
- 03:37transcription factors are proteins that
- 03:39regulate gene expression. So we
- 03:40have about fifteen hundred of
- 03:42these named, in the human
- 03:44genome. And what they do
- 03:45is they're small proteins or
- 03:46they're proteins that bind gene
- 03:48promoters
- 03:49or enhancers
- 03:50or silencers
- 03:51to alter gene expression.
- 03:53They they recruit, you know,
- 03:54different proteins and stuff. But
- 03:55by and large, what they
- 03:56do is they bind what
- 03:58we call cis regulatory elements
- 04:00to
- 04:01alter expression of a given
- 04:02gene.
- 04:04And these can be extremely
- 04:05powerful in in their So,
- 04:08this is Shinya,
- 04:10Yamanaka. He won the Nobel
- 04:11Prize in twenty twelve. He's
- 04:13kind of a hero to
- 04:14many of us.
- 04:15So he showed something really
- 04:17amazing,
- 04:18that he got the Nobel
- 04:19Prize for. He showed that
- 04:20you could take an adult
- 04:21dermal fibroblast,
- 04:22add four transcription factors, and
- 04:24turn it into an induced
- 04:25pluripotent stem cell.
- 04:27Those four transcription factors are
- 04:29SOX2, WAC4, KLF4,
- 04:31and and MYC.
- 04:33And so him and and
- 04:34others who worked in this
- 04:36space kinda bulldozer an old
- 04:37idea. The old idea was
- 04:39this this idea of Waddington's
- 04:40canals. This idea that that
- 04:42embryologic tissue was,
- 04:44was, destined to become one
- 04:46thing, and it couldn't really
- 04:46back up. It was like
- 04:47once you got to a
- 04:48certain degree of differentiation, you
- 04:50didn't reverse it. And he
- 04:51showed that four transcription factors
- 04:53can reverse it, which is
- 04:54kind of amazing. And that's
- 04:55why I won the Nobel
- 04:56Prize. And it it also
- 04:57goes to show the the
- 04:58incredible power
- 05:00of even a few,
- 05:02small proteins. A few transcription
- 05:03factors can drive tremendous phenotypic
- 05:06change,
- 05:07in in in a cell.
- 05:11And so one of the
- 05:12things that, makes some a
- 05:14subset of these transcription factors
- 05:16so powerful
- 05:18is they're called pioneer facts,
- 05:20pioneer transcription factors. And so
- 05:22as whereas many factors can
- 05:23only bind chromatin that's opened
- 05:25and has their their response
- 05:26elements or the areas they
- 05:27bind, open, pioneer factors can
- 05:30open close chromatin.
- 05:31And they can change the
- 05:33the the epigenomic landscape,
- 05:35truly
- 05:36of of, DNA that they're
- 05:37they're exposed to. And so
- 05:39three of these I've named
- 05:40because they're important in in
- 05:41bladder cancer. So one is
- 05:42Fox a one.
- 05:44That's a pioneer factor that's
- 05:45known to be important in
- 05:46in breast cancer, for example,
- 05:47in ER and AR binding.
- 05:49This one's particularly well studied.
- 05:51It it mimics a link
- 05:52or histone. That's how it's
- 05:53able to open up, close
- 05:55chromatin.
- 05:56Two other ones, GATA3 p,
- 05:57PAR gamma, these are probably
- 05:59also pioneer factors.
- 06:01So these these are,
- 06:02transcription factors, again, that can
- 06:04bind closed chromatin fundamentally on
- 06:06their own, change the the
- 06:08epigenomic landscape,
- 06:10is just a few a
- 06:11few of these these transcription
- 06:13factors.
- 06:16So let's talk about bladder
- 06:17cancer. So so bladder cancer
- 06:19has a very well well
- 06:21known progression.
- 06:23Those in the urology world
- 06:24and the the geopathology world
- 06:25know it well.
- 06:27Starts off as noninvasive disease,
- 06:29like like all cancers
- 06:30do. Either t, TIS or
- 06:32flat carcinoma in situ or
- 06:34TA, which is this noninvasive
- 06:36papillary tumor. It's kinda like
- 06:37a like a bush growing
- 06:39on the surface or like
- 06:39a cauliflower.
- 06:41It invades the lamina propria.
- 06:42That's the superficial connective tissue
- 06:44underneath the urothelium,
- 06:46continues to progress into the
- 06:47the the muscular layer, the
- 06:49muscularis propria of the bladder
- 06:50extends outside of it, and
- 06:52then eventually extends into other
- 06:53organs. So we generally call
- 06:55this non invasive tumor. We
- 06:57call it non muscle invasive
- 06:58if it's up to a
- 06:59t one because it's not
- 07:00quite in muscle. And then
- 07:01we've got muscle invasive bladder
- 07:02cancer whenever it's beyond that.
- 07:04And this is used to
- 07:05to classify,
- 07:06you know, treatments and and
- 07:07and breakdown,
- 07:08you know, different prognostic tests
- 07:11and things. So let's keep
- 07:12this in mind as we
- 07:13as we keep chatting about
- 07:14the rest of the of
- 07:14the talk.
- 07:16And so this is the
- 07:17histology of of most bladder
- 07:18cancers. So this is urothelial
- 07:20carcinoma. This is the stage
- 07:21TA, the non invasive papillary
- 07:23tumor that we talked about.
- 07:24It's got these fibro vascular
- 07:25cores. It's got these this
- 07:27urothelial
- 07:27thickening. There's fusion. It's really
- 07:29just kinda confused cauliflower thing
- 07:31growing off the surface of
- 07:32the urothelium.
- 07:34You've got stage TIS or
- 07:35flat carcinoma in situ. It's
- 07:36these malignant cells sitting on
- 07:38the surface.
- 07:39Then you've got invasive urothelial
- 07:40carcinoma.
- 07:41Kinda looks like urothelial. It's
- 07:43not really as, you know,
- 07:44easy to describe as a
- 07:45lot of cancer types like
- 07:46colon cancer and stuff. But
- 07:48it's these jagged, you know,
- 07:49infiltrative nests of cancer that
- 07:50looks kinda like urothelial. And
- 07:52this is the astrology of
- 07:53t one. So the lamina
- 07:54appropriate invasive stuff, and then
- 07:56anything beyond that.
- 08:00So we can also classify
- 08:02bladder cancers into this, this
- 08:03luminal versus basal,
- 08:06dichotomy.
- 08:07And this got a lot
- 08:07of attention, about ten years
- 08:09ago. And so the luminal
- 08:11cancers tend to express, urothelial
- 08:13genes. So FOXA one, you
- 08:14know, get a three, PPAR
- 08:16gamma, uroplacants.
- 08:17They're enriched in FGFR three
- 08:18mutations. Then there's the basal
- 08:19cancers. Those express basal genes.
- 08:22They're enriched in high molecular
- 08:23weight keratins, TFAPs. They're also
- 08:25enriched in t p TB
- 08:26fifty three gene mutations.
- 08:28And so there was an
- 08:29idea about ten, eleven years
- 08:31ago when they this this,
- 08:32I think, first came out
- 08:33in bladder cancer, and this
- 08:34idea was that we have
- 08:35intrinsic subtypes. We've identified intrinsic
- 08:38molecular subtypes of bladder cancer,
- 08:39and we can start tailoring
- 08:41our treatments to these two
- 08:42different
- 08:43molecular subtypes. And a lot
- 08:44of attention, a lot of
- 08:45money, and a lot of
- 08:46effort went into coming up
- 08:48with ways to to treat
- 08:49these these different molecular subtypes.
- 08:53And I submit to you
- 08:54that that is not the
- 08:55case. They are not intrinsic.
- 08:57This is not a story
- 08:57of intrinsic molecular subtypes that
- 08:59are born basal or born
- 09:00luminal.
- 09:01The story of bladder cancer,
- 09:03the story of luminal and
- 09:04basal is a story of
- 09:05lineage plasticity.
- 09:07And
- 09:08the utility of the luminal
- 09:10and basal is really not
- 09:11in naming them a luminal
- 09:12cancer or basal cancer, but
- 09:14rather the utility is understanding
- 09:16the drivers of luminal differentiation,
- 09:18the drivers of basal differentiation,
- 09:20and how we can exploit
- 09:21those in the future
- 09:22to treat patients with bladder
- 09:24cancer.
- 09:28So so here's some relevant
- 09:29signatures whenever you break these
- 09:31these tumors down. So,
- 09:33what these data are are
- 09:34from the Cancer Genome Atlas,
- 09:36bladder cancer data, which is
- 09:37a nice repository if you
- 09:38wanna just look at stuff.
- 09:41And so what we did
- 09:42is we we took the
- 09:43cancer genome atlas,
- 09:45invasive bladder cancers, divided them
- 09:46into luminal versus basal based
- 09:48on, you know, just the
- 09:49standard, you know, dichotomous, you
- 09:51know, change. And then we
- 09:52looked at single sample gene
- 09:53set enrichment analysis scores,
- 09:55and then compared them, in
- 09:57these different scores. So as
- 09:58expected, luminal cancers tend to
- 10:00have, you know, high expression
- 10:01of luminal genes.
- 10:03Basal cancers tend to have
- 10:04higher expression of basal genes.
- 10:05This is obvious. But there's
- 10:07some things that that pop
- 10:08out that are
- 10:09also of of of value.
- 10:11One is cell cycle activity.
- 10:12It's a little bit higher
- 10:13in basal versus luminal. Another
- 10:15is inflammatory signature. So this
- 10:16is just, you know, our
- 10:17standard hallmark inflammation
- 10:19kinda signature.
- 10:20And it shows that the
- 10:21basal cancers are
- 10:23enriched largely in in an
- 10:25inflammatory signature.
- 10:27And perhaps more importantly,
- 10:29basal tumors are heavily enriched
- 10:31at interferon gamma activity.
- 10:33So we name them after
- 10:34the epithelial cell that they're
- 10:36differentiating toward more basal, more
- 10:37squamous.
- 10:38But whenever we break it
- 10:40down and look at the
- 10:41signatures, interferon gamma is extremely
- 10:43strong in the basal squamous
- 10:45or the basal type of
- 10:46bladder cancer.
- 10:51And molecular subtype also associates
- 10:53strongly with stage.
- 10:54And so to my mind,
- 10:56if these were intrinsic and
- 10:57they were either born basilar,
- 10:58they were born luminal,
- 11:00you would see precursors that
- 11:02are basal. You would see
- 11:04precursors that are luminal and
- 11:05they would be in roughly
- 11:06equal proportion, but that's not
- 11:08the case at all.
- 11:10It turns out that the
- 11:11vast majority of non invasive
- 11:12and even early stage invasive
- 11:14cancers are luminal.
- 11:15Whereas the basal nist, the
- 11:17basal phenotype doesn't really show
- 11:18up until you're in the
- 11:19muscle invasive stage.
- 11:21And so these data are,
- 11:23combined,
- 11:25cancer genome at least data
- 11:26for muscle invasive tumors. And
- 11:28then there's this large European
- 11:29study,
- 11:31Linsgrogg et al. They had
- 11:32the TA and t one
- 11:33cancers. So we the the
- 11:35analysis we're looking at here,
- 11:36was one of my group,
- 11:37we we lumped the cases,
- 11:38normalized them, and then used
- 11:40a UNC classifier that's published
- 11:41at University of North Carolina
- 11:42into either luminal or basal.
- 11:44And as expected,
- 11:45based on some prior studies,
- 11:46the TA were vast majority,
- 11:48ninety five percent plus for
- 11:49luminal.
- 11:51Most of the t ones,
- 11:52which is somewhat surprising, were
- 11:53also luminal, whereas the,
- 11:55the muscle invasive cancers, those
- 11:57that were in the muscular
- 11:58as appropriate or deeper were
- 11:59about half luminal, about half
- 12:00base. So this this to
- 12:02me even, like, looking at
- 12:03it says that this is
- 12:04a a story of these
- 12:05things changing as they develop
- 12:06higher stage disease.
- 12:12Okay.
- 12:13Did I break it? There
- 12:14we go. Okay.
- 12:15And so, there's another piece
- 12:17to the story in the
- 12:18histology that really starts to
- 12:20argue for lineage plasticity playing
- 12:22an important role in this
- 12:24phenotypic evolution. So,
- 12:26in
- 12:27bladder cancer world and the
- 12:28residents, we talked about these
- 12:29this morning and Tuesday morning,
- 12:31they're probably tired of me
- 12:32at this point.
- 12:35So the bladder cancer has
- 12:36many,
- 12:37histologic variants or
- 12:39divergent differentiation or histologic subtypes.
- 12:40There's a bunch of ways
- 12:41to describe these, but they're
- 12:43named histomorphologies
- 12:44that have specific,
- 12:46clinical correlations and complete and
- 12:48specific prognostic, you know, implications.
- 12:50You know, one of those
- 12:51is micropapillary. That's these tiny
- 12:53little, you know, micropapillary nest
- 12:55with attraction clefts. We've got
- 12:56plasmacytoid that's infiltrative single cells.
- 12:58We've got glandular, that means
- 12:59it's it's making glands.
- 13:01Nested, that means it's little
- 13:02tiny blend nest that are
- 13:03easy to to miss. Got
- 13:04small cell that looks like
- 13:05small cell lung cancer. You've
- 13:06got squamous carcinoma that's making
- 13:08keratin, not to be confused
- 13:10with with basal or basal
- 13:11squamous, which is usually what
- 13:12we use to describe, you
- 13:13know, the molecular subtypes. But
- 13:15rather, it's histologic squamous differentiation
- 13:17where it's making making keratin.
- 13:19You have lymphopodeal leoma like,
- 13:21that looks like nasopharyngeal carcinoma,
- 13:23which is an EBV mediated
- 13:25phenomenon with an intense inflammatory
- 13:26infiltrate.
- 13:27This actually isn't EBV mediated.
- 13:29It just looks like a
- 13:30nasopharyngeal tumor that, that is.
- 13:33Then there's sarcomatoid,
- 13:34which is relatively common, but
- 13:36it's differentiating towards a sarcoma.
- 13:38And so this is the
- 13:40the the diversity of, you
- 13:41know, of of bladder cancer
- 13:43for the large part.
- 13:46And these things tend to
- 13:47have, consistent
- 13:49molecular subtypes.
- 13:51Not perfect, but there's a
- 13:53strong tendency here. So, the
- 13:54plasmacytoid, the micropapillary, the nested,
- 13:56they tend to be luminal.
- 13:59The lymphopithelium
- 14:00alike, the squamous, histologically squamous
- 14:02tend to be basal.
- 14:03The sarcomatoid kinda do whatever
- 14:05they wanna do. They're turning
- 14:06into sarcomas, so they're a
- 14:07little wild.
- 14:09The glandular,
- 14:10you know, they make glands.
- 14:11They can be variable as
- 14:12well.
- 14:13You know, in neuroendocrine,
- 14:15the small cell, they have
- 14:16neuroendocrine phenotype, you know, they're
- 14:17not really getting, you know,
- 14:18you're the only one anymore.
- 14:20And so there's, you know,
- 14:22not only and my phone
- 14:23is just buzzing. Hold on.
- 14:25Spam. Do you guys get
- 14:26spammed constantly? It's making me
- 14:27crazy. It's, like, half ninety
- 14:29percent of my calls.
- 14:31Okay. So, so back to
- 14:32this. So,
- 14:35these histologic variants
- 14:37strongly associate with these specific
- 14:39molecular subtypes.
- 14:43And so, you know, back
- 14:45in twenty nineteen, we had
- 14:46a study published in European
- 14:48urology that got a lot
- 14:49of attention.
- 14:50Because
- 14:51before the study came out,
- 14:52there was this, like I
- 14:53said, there was this
- 14:54intense interest in intrinsicness
- 14:57of of these molecular subtypes.
- 14:59And there have been clinical
- 15:00trials that were being developed,
- 15:01putting people in these different
- 15:02subtypes and then treating them
- 15:03differently based on the the
- 15:05the classifications.
- 15:07And this study was one
- 15:07of the first to really
- 15:08kind of, you know, shoot
- 15:09a hole on that idea.
- 15:10And so what we did
- 15:11is we took about three
- 15:12hundred,
- 15:14consecutive,
- 15:15cystectomy cases. We mapped them
- 15:16out.
- 15:17We identified all the different
- 15:19areas of histologically distinct invasive
- 15:20carcinoma. We,
- 15:22named them. We identified areas
- 15:23of non invasive carcinoma,
- 15:25and we performed molecular subtyping
- 15:27on them using, the,
- 15:30a group or a a
- 15:31schema developed by the Lund
- 15:32University,
- 15:35in,
- 15:36in in Switzerland. No. Sweden.
- 15:38In Sweden. They would make
- 15:39they would be angry if
- 15:40I said they were Swiss.
- 15:41But they're, they developed this,
- 15:44system for for molecular classification.
- 15:47And so they have a,
- 15:48you know, this kind of
- 15:49type where they call them
- 15:50urothelial like and genomically unstable,
- 15:51but really practically speaking, those
- 15:53are those are luminal. They
- 15:54have a basal squamous equivalent
- 15:56to a basal on the
- 15:56other systems. They have mesenchymal
- 15:58like that is really rare,
- 15:59kind of like sarcoma, and
- 16:00then they have non type.
- 16:01What we did is we
- 16:02performed molecular subtyping on all
- 16:04the different areas from these
- 16:05bladders that we mapped out.
- 16:07And this is how we
- 16:08demonstrated those that had,
- 16:10you know, histologic diversity.
- 16:12And so each column is
- 16:14a histology, we've got conventional
- 16:15urothelial, squamous, micropapillary, glandular, etcetera.
- 16:18Each row is a patient,
- 16:20and then each color is
- 16:22a a molecular subtype.
- 16:24So what we we see
- 16:25here is that if we
- 16:27go along each row, we
- 16:28can see the different histologies
- 16:29each patient had. Gray means
- 16:31they didn't have it. Then
- 16:32we can see what molecular
- 16:33subtype they were assigned to.
- 16:35And what we can see
- 16:35here is that there's diversity.
- 16:37They're not all the same.
- 16:39They're not intrinsic.
- 16:40They differ. So for example,
- 16:42this first row of the
- 16:43conventional urothelial was a luminal
- 16:45subtype and associated histologically squamous
- 16:47was basal squamous.
- 16:49Same thing with these guys.
- 16:51Here, this was also luminal.
- 16:52These are basal squamous. The
- 16:53conventional was urothelial. The histologically
- 16:56squamous was a basal subtype.
- 16:58And then it gets even
- 16:58more interesting. Some have, you
- 17:00know, like
- 17:01a, you know, basal conventional
- 17:03urothelial, basal squamous, then there's
- 17:04a micropapillary in a different
- 17:05area that was luminal.
- 17:07So this
- 17:08really is one of the
- 17:09first indications that, like, no.
- 17:10These things are not just
- 17:11born one way and they
- 17:13stay that way. There's plasticity
- 17:14going on. These are changing
- 17:15as they evolve from different
- 17:17to different,
- 17:18histologies.
- 17:19And in fact, thirty nine
- 17:20percent of cases
- 17:22in which there was histologic
- 17:23diversity also demonstrated a difference
- 17:25in molecular subtype, and it's
- 17:27extremely common in those that
- 17:28had a basal squamous component.
- 17:30There was even one basal
- 17:31squamous component. Nearly eighty percent
- 17:33had another area that was
- 17:34luminal.
- 17:35It could have been the
- 17:36non invasive component, could have
- 17:37been another, but it really
- 17:38demonstrated that there's a a
- 17:39tremendous amount of,
- 17:41diversity in terms of the
- 17:42luminal versus basal,
- 17:44dichotomy in these things.
- 17:46And so that led to
- 17:47a different framework than they're
- 17:48born luminal or they're born
- 17:50basal, but rather they're mostly,
- 17:51if not all born, luminal.
- 17:53And certainly we can't be
- 17:54absolute here. This is
- 17:56this is cancer. It kind
- 17:56of does what it wants.
- 17:57We've seen squamous displays in
- 17:59the bladder, but by and
- 18:00large,
- 18:01most of these things start
- 18:02off, we think is not
- 18:03invasive. You're of the ileal
- 18:04carcinoma that's luminal. It invades
- 18:06like we see with the
- 18:07t one cancers that are
- 18:08luminal And early on, it's
- 18:10the invasive cancers also luminal.
- 18:11And then from there, it
- 18:13it undergoes lineage plasticity
- 18:15to a basal subtype.
- 18:16And those can turn into
- 18:17histologic,
- 18:19basal variance. And then the
- 18:20urothelial conventional can turn into
- 18:22invasive histologic luminal,
- 18:24variance.
- 18:25So this is the framework
- 18:26that we're working from now.
- 18:27And so,
- 18:29you know, the one of
- 18:30the questions as well, how
- 18:31do you know that it's
- 18:32not just, like, you know,
- 18:33collision tumors? Why aren't the
- 18:34why were the luminal micropapularies
- 18:36and the histologically squamous basal
- 18:38ones? Are they two separate
- 18:39tumors
- 18:40that just collided? And it's
- 18:42just a coincidence, and I
- 18:43think the answer is no.
- 18:44And we we answered that
- 18:46with, the paper, in nature
- 18:47communications a few years back.
- 18:49This was a collaboration with,
- 18:52Memorial Sloan Kettering, Hikma Del
- 18:53Amadi, and,
- 18:54Wenohu,
- 18:55were two of the main
- 18:56collaborators there. And so what
- 18:58we did in in this
- 18:59study is we,
- 19:01gathered
- 19:02a number of patients, twelve
- 19:04in total, who had invasive
- 19:06urothelial carcinomas with a clearly
- 19:08conventional urothelial carcinoma component
- 19:10and a clearly squamous invasive
- 19:12squamous carcinoma component. And we
- 19:14did,
- 19:16you know, comprehensive genomic evaluation
- 19:18on them or at least
- 19:19what was called comprehensive at
- 19:20the time. So we did,
- 19:21whole exome sequencing. We did
- 19:23RNA sequencing.
- 19:25We did this on a
- 19:25lot more than twelve, but
- 19:26the we only kept the
- 19:28twelve that had high quality
- 19:29RNA. It's difficult to get
- 19:30high quality RNA out of
- 19:31tissue blocks.
- 19:33So we we performed RNA
- 19:35sequencing,
- 19:35sequencing.
- 19:37And then we we, you
- 19:38know, saw the results. And
- 19:39this is the first thing
- 19:40we saw
- 19:42was the the the pair
- 19:43urothelial carcinomas and squamous carcinomas,
- 19:46were clonally related, but subclonally
- 19:48distinct.
- 19:49And so they were all,
- 19:50all twelve of them had
- 19:52multiple,
- 19:54cancer driver genes that were
- 19:55identical between the two different
- 19:56histologies. So for example, we've
- 19:58got, you know, we're demonstrating
- 19:59here, we've got the urothelial
- 20:00component, the squamous component
- 20:02Here, we've got,
- 20:05you know, like, the common
- 20:06precursor presumed common precursor.
- 20:08Here's the common mutations between
- 20:10the two. Here's common or
- 20:12here's mutations exclusive to the
- 20:13squamous component. Here's, mutations unique
- 20:16to the erythema component. And
- 20:17so these are just three
- 20:18example cases.
- 20:20So in this one, they're
- 20:22identical.
- 20:23You know, cancer driver mutations
- 20:25in Fgfr3, TP53, PIK3CA, and
- 20:27then thirty one more that
- 20:28were common to both. They
- 20:29were unique mutations in both
- 20:31the squamous and urothelial components.
- 20:33Same with this one, also
- 20:34f g f r three
- 20:35mutations. And remember, f g
- 20:36f r three is more
- 20:37associated with luminal cancer, and
- 20:38these developed histologically squamous disease.
- 20:40So
- 20:41this is really screaming lineage
- 20:43plasticity to my mind. So
- 20:44you've got f g f
- 20:45r three, you've got ATM,
- 20:47we've got PIK3CA.
- 20:48Again, there's some unique mutations
- 20:50in the squamous component including
- 20:51TP53.
- 20:53And then the same with
- 20:53this one, it's not an
- 20:54FGFR3 mutant cancer, but it's
- 20:57got,
- 20:58multiple
- 20:59known cancer driver genes between
- 21:01both the urothelial component and
- 21:03the paired histologically squamous component.
- 21:05Really, I think
- 21:07proving that these things iterize
- 21:09from a common precursor despite
- 21:10their distinct
- 21:11histology.
- 21:15So what about, your molecular
- 21:17subtype, this luminal versus bathel
- 21:20dichotomy? So we have the
- 21:21RNA Seq data. We only
- 21:22selected cases that had, you
- 21:24know, high quality RNA sequencing
- 21:25data.
- 21:26Anew did a few things.
- 21:28First, we put them into
- 21:29categorical,
- 21:30luminal versus basal subtypes
- 21:32based on the TCGA system
- 21:34and and centroid analysis. So
- 21:35that's shown here.
- 21:37Each column is a patient.
- 21:39Each row is a histology.
- 21:40So this is the urothelial
- 21:41part. This is the squamous
- 21:43part. The color is the
- 21:44subtype.
- 21:45So that's kinda orange salmon
- 21:47color is basal.
- 21:48Then the blue and the
- 21:49green are both luminol subtypes.
- 21:51There are a lot of
- 21:51different systems. The TCGA has
- 21:53one that's subclassified as liminal,
- 21:54but we'll pull them, for
- 21:56the sake of, you know,
- 21:56simplicity in the discussion.
- 21:58And four of the twelve,
- 22:01switched subtype,
- 22:02whenever we use the centroid
- 22:03analysis.
- 22:04So using the subtype as
- 22:06a categorical variable centroid analysis,
- 22:09we saw that, you know,
- 22:10a third of them were
- 22:11different between the two. This
- 22:12is consistent with what we
- 22:13found earlier.
- 22:15And and
- 22:16I think more interestingly, we
- 22:17found that it it it
- 22:19was went beyond that. So,
- 22:22we performed, you know, single
- 22:24sample gene set of enrichment
- 22:25analysis with gene lists of
- 22:26basal genes and and luminal
- 22:28genes to give a quantified
- 22:29or quantitative score of baseness
- 22:32and luminous.
- 22:34In every single case, the
- 22:35squamous component had a higher
- 22:37basal score than the luminal
- 22:39than the urothelial component.
- 22:41And in every single case,
- 22:42the squamous component had a
- 22:43lower luminal score than the
- 22:45urothelial component.
- 22:47Really showing that this it
- 22:49it's really, I think, putting
- 22:50more and more cracks in
- 22:51this idea of luminal versus
- 22:52basal dichotomy. That that we
- 22:54we have not only that
- 22:55a third of them change
- 22:57subtype,
- 22:58but that all of them
- 22:59are more basal, and all
- 23:00of them are less liminal.
- 23:02So this is looking more
- 23:03like a continuous variable than
- 23:04it is like a categorical
- 23:05variable.
- 23:08How about, you know, we
- 23:09talked about that,
- 23:11immunity,
- 23:12before.
- 23:13We talked about how they're
- 23:14the interferon gamma,
- 23:17and just looking at these
- 23:18subtypes is higher in the
- 23:19basal subtype, and it's pretty
- 23:20significantly higher. So what about
- 23:22immune
- 23:24subtype,
- 23:25between the urothelial and the
- 23:26histologically squamous components?
- 23:28So, we handle this in
- 23:30a few ways. One of
- 23:31them is we assign them
- 23:33what was called an immune
- 23:34subtype. So this group, you
- 23:35know, Thorson et al published
- 23:37a nice paper in immunity
- 23:38in twenty eighteen,
- 23:39that I found is really
- 23:40useful where they assigned six
- 23:41different inflammatory
- 23:43subtypes,
- 23:44to cancers, you know, based
- 23:46on on, you know, the
- 23:47TCGA data.
- 23:48They named them c one
- 23:49to c six.
- 23:51C two is an interferon
- 23:52gamma dominant
- 23:53in, inflammatory subtype. And then
- 23:56there's a number of other
- 23:56ones. C one's wound healing.
- 23:58C three is inflamed.
- 23:59They have a number of
- 24:00other named ones.
- 24:01And so we used our
- 24:03RNA sequencing data to put
- 24:04the the tumors into,
- 24:07these thorasin immune subtypes.
- 24:09And not surprisingly, we found
- 24:10all the histologically squamous areas,
- 24:13where the c two interferon
- 24:15gamma dominant
- 24:17subtype. We similarly found that,
- 24:20nine of the twelve,
- 24:21urothelials were also, you know,
- 24:23the c two interferon,
- 24:25dominant, but three of them
- 24:26were not. So there was
- 24:27some heterogeneity,
- 24:29in the immune subtype
- 24:31in in these tumors.
- 24:33PDL one also differed. And
- 24:34so,
- 24:36PDL one is a a
- 24:37target of interferon gamma. So
- 24:39interferon
- 24:40gamma signaling induces higher PDL
- 24:42one expression. This is pretty
- 24:43well well known. And the
- 24:44squamous component on average had
- 24:46higher PDL1 expression of the
- 24:47urothelial.
- 24:49So
- 24:50not only are they histologically
- 24:52different,
- 24:53and they're different in their
- 24:54immune sub their their molecular
- 24:55subject, their immune subtype seems
- 24:56to be different as well.
- 24:58So So this lineage plasticity
- 24:59is taking on a kind
- 25:00of a life of its
- 25:01own.
- 25:04And so what does it
- 25:05matter at this point? Right?
- 25:07That's always the question I
- 25:08like to ask myself. Why
- 25:09is this important?
- 25:10And so,
- 25:12Hikmat Elhamdi,
- 25:13from Sloan Kettering, he's a
- 25:14pathologist out there. So he
- 25:16was part of, one of
- 25:17the clinical trials that looked
- 25:19at at atezolizumab
- 25:20in metastatic and locally invasive
- 25:22bladder cancer.
- 25:23And so he was one
- 25:24of the guys who reviewed
- 25:25the slides and confirmed its
- 25:26bladder cancer and all that
- 25:27kind of stuff. And so
- 25:29he he he had an
- 25:30idea. He's like, alright. So
- 25:31we see this immune heterogeneity
- 25:33in our tumors. So I'm
- 25:35gonna
- 25:36grab the the tumors from
- 25:37Sloan Kettering that were part
- 25:38of this this clinical trial.
- 25:40I'm just gonna look at
- 25:41them blinded, and I'm gonna
- 25:42break down, is there histologic
- 25:44heterogeneity or not? Or is
- 25:46there morphologic heterogeneity?
- 25:47And he defined this precisely.
- 25:49He said, is it a
- 25:50named are there more than
- 25:51one named histology
- 25:53in this in this tumor?
- 25:55Yes or no? Just kinda,
- 25:56you know, made us hash
- 25:57marks. And then we did
- 25:58the statistics in terms of,
- 26:01response or no response.
- 26:03And it turned out those
- 26:04with,
- 26:05morphologic heterogeneity
- 26:08were enriched in the non
- 26:09responder group.
- 26:11Whereas those who
- 26:13lacked morphologic heterogeneity
- 26:15were enriched in the responder
- 26:17group. Certainly a small n,
- 26:18but it was significant and
- 26:19it was it was impressive.
- 26:21And so one of the
- 26:22thoughts here is that maybe
- 26:24we know there's this immune
- 26:26heterogeneity or we've seen this
- 26:27immune heterogeneity.
- 26:29Are these tumors with immune
- 26:30heterogeneity in spatially distinct areas
- 26:32better able to adapt
- 26:34to immune checkpoint inhibitor because
- 26:35they have
- 26:37this greater diversity to
- 26:39get around it. And so
- 26:41this is likely clinically important.
- 26:44So what about the experimental
- 26:46data?
- 26:46You know, this is all
- 26:47observational. You know, we've we're
- 26:49looking at human tumors. This
- 26:50is really pointing at,
- 26:52lineage plasticity as being being
- 26:53important here.
- 26:57Being the driver of, you
- 26:58know, the luminal versus basal
- 27:00dichotomy.
- 27:01What about experimental data? So
- 27:04I'll give it away, the
- 27:05experimental data is pretty good
- 27:07and we I think we've
- 27:08identified some main drivers
- 27:10of both luminal differentiation
- 27:12and of basal differentiation. And
- 27:14I think the luminal differentiation
- 27:16is driven by a few
- 27:17transcription factors and basal
- 27:19differentiation appears driven heavily by
- 27:21interferon gamma signaling. So I'll
- 27:23tell you the evidence we've
- 27:24got right now. So this
- 27:25is an older paper, we
- 27:26published twenty sixteen,
- 27:29where we,
- 27:31asked the question, can we
- 27:32change the molecular subtype
- 27:34of bladder cancer cell lines?
- 27:36So what we did is
- 27:37we,
- 27:39took the cancer cell line
- 27:40encyclopedia data, which is, you
- 27:41know, publicly available expression data
- 27:43for cell lines. We put
- 27:44them into two categories, either
- 27:45basal cell lines, luminous or
- 27:47luminal cell lines. We threw
- 27:48away a bunch of them
- 27:49because they didn't really, you
- 27:50know, have the expression pattern
- 27:51of either.
- 27:53Then we picked one of
- 27:53the basal cell lines, five
- 27:55six three seven. This is
- 27:57the CCLE one. This is
- 27:58ours.
- 27:59And we
- 28:01saw if we could push
- 28:02it from basal to luminal
- 28:03using transient transfection with,
- 28:07Foxy one, get a three,
- 28:08and then use rosaglitazone
- 28:10to is a PPAR gamma
- 28:12agonist to see if activation
- 28:13of these three transcription factors
- 28:15could push
- 28:16it. And and they did,
- 28:17and they impressively so. So
- 28:19here's our,
- 28:21five six three seven controls.
- 28:23This is FOXA one alone.
- 28:25This is got a three
- 28:25alone. This is FOXA one
- 28:26and got a three. Together
- 28:27you kinda get the picture.
- 28:29This is a centroid plot,
- 28:30so this is a basal
- 28:31centroid correlation.
- 28:33The higher it is, the
- 28:34more basal,
- 28:35the cell line is. Here's
- 28:37the luminal centroid correlation, the
- 28:38higher it is, the more
- 28:39luminal,
- 28:40the cell line is. And
- 28:42as we add more transcription
- 28:43factors, we we push them
- 28:45more in the liminal direction.
- 28:47To the point where when
- 28:47we've added all three transcription
- 28:49factors,
- 28:50we consistently, and at least
- 28:51two replicates, and this is
- 28:52we've seen beyond this, we
- 28:54push them to a a
- 28:55luminal phenotype.
- 28:56And
- 28:58so, go back to Yamanaka
- 28:59factors, we can turn a
- 29:00fibroblast
- 29:01into an induced pluripotent stem
- 29:03cell with four transcription factors.
- 29:05It looks like we can
- 29:06turn a bladder cancer cell
- 29:07line from a basal type
- 29:08to a luminal
- 29:10type with three.
- 29:16And so what are the
- 29:17opposite direction?
- 29:18So
- 29:19the next thought is we
- 29:20FOXA1 seems like the best
- 29:22established. We knew more about
- 29:23FOXA1
- 29:24than any of these other
- 29:25factors.
- 29:27So we're like, what happens
- 29:28if we knock out FOXA1?
- 29:29So we knocked out FOXA1
- 29:31in a couple of luminal
- 29:31cell lines,
- 29:33and it doesn't just turn
- 29:34into basal.
- 29:35It doesn't just you know,
- 29:36you knock out FOXA1, they
- 29:37become basal. That doesn't happen
- 29:38at all. There's buffering in
- 29:40there.
- 29:41Just kinda like they're not
- 29:42even that much more more
- 29:43basal really when you knock
- 29:44out Fox a one. And
- 29:45we've done this with visa
- 29:46lines,
- 29:47but something else does happen.
- 29:49That's kinda telling, kinda fascinating
- 29:51and probably important.
- 29:53And I think it comes
- 29:54to, you know, what I
- 29:55was saying earlier about,
- 29:57molecular subtypes being not as
- 30:00important as a categorical things.
- 30:01We put things in and
- 30:02treat people differently, but giving
- 30:04us an understanding and insight
- 30:06into where the Achilles
- 30:07heels
- 30:08in bladder cancer. What are
- 30:10the super important
- 30:11little triggers that we can
- 30:12we can work with? And
- 30:13I think Fox a one
- 30:14is one of them. And
- 30:15I think
- 30:16that one of the pieces
- 30:18of data we have that
- 30:18is if you knock out
- 30:19Fox a one in a
- 30:21luminal cell line, it doesn't
- 30:22become basal,
- 30:24but it turns up interfering
- 30:26gamma signal,
- 30:28which is kinda weird. So
- 30:30like these are cell lines,
- 30:31these are not CD eight
- 30:32cells.
- 30:33These these are just epithelial
- 30:34cells,
- 30:36but the the basal cell
- 30:37lines tend to over express,
- 30:40interferon gammas even though they're
- 30:41just cell lines, whereas the
- 30:42luminal ones have lower expression.
- 30:44But if you take a
- 30:44luminal one, you knock out
- 30:46FOXA1, you turn up interferon
- 30:48gamma signaling, you don't do
- 30:49it subtly.
- 30:51So here's the here's the
- 30:52data for that. So,
- 30:53here we used the UMEC
- 30:55one,
- 30:56luminal cell line.
- 30:58There's this is our expression
- 30:59data from RNA sequencing,
- 31:01ROSA genes. These are some,
- 31:02what are called the interferon
- 31:04response genes.
- 31:05Blue is higher, red is
- 31:06lower. Wen Ho did that.
- 31:07Blame him. He's one of
- 31:08our collaborators. I wish we
- 31:09did on the opposite.
- 31:11But what it showed is
- 31:12that on our knockouts, we
- 31:13see this substantial increase in,
- 31:16expression of interferon
- 31:18responsive genes in our knockouts.
- 31:20And and we saw the
- 31:21same with interferon alpha signaling,
- 31:22interferon gamma signaling using, you
- 31:24know, standard GSEA.
- 31:26We also saw that when
- 31:27we knocked out FOXA1 PDL1
- 31:29expression went up, which we
- 31:30know is a a downstream,
- 31:31you know, product of interferon
- 31:33gamma signaling.
- 31:34So so this is, I
- 31:35I think, a potentially important
- 31:37thing, and we're digging into
- 31:38this a lot. We talked
- 31:38a little bit about this
- 31:39on on Tuesday at the,
- 31:41the the rip talk. But,
- 31:43this is, I think, an
- 31:44important thing
- 31:45in developing, you know, customized
- 31:46treatments for for, for bladder
- 31:49cancer. And we're we're continuing
- 31:50to work on on what
- 31:51this means.
- 31:54And it, you know, raises
- 31:55another question too. So, okay,
- 31:56we this is this is
- 31:57kind of strange. We knock
- 31:58out FOXA1
- 31:59in epithelial cancer cell lines.
- 32:02We drive interferon gamma signaling
- 32:04even though there's no inflammatory
- 32:05cells to be found.
- 32:07And we know that
- 32:08if through through some other
- 32:09data that, you know, basal
- 32:11squamous bladder cancers not only
- 32:12have higher interferon gamma signaling,
- 32:14but they're inflamed. There are
- 32:15more, you know, immune cells
- 32:16in them.
- 32:18How's it getting there? And
- 32:19the question arose, like, does
- 32:20what does interferon gamma do
- 32:23to luminal cell lines? So
- 32:25we know if we knock
- 32:25out FOXA1 in the luminal
- 32:27cell line, we turn into
- 32:28a basal cell line. What
- 32:29if we take a liminal
- 32:30cell line, we treat it
- 32:31with interferon gamma, what happens?
- 32:33And it turns out they
- 32:34turn basal
- 32:36or they get more basal
- 32:37at least. So what we
- 32:38did, here's three, liminal cell
- 32:40lines, r t one one
- 32:41two,
- 32:44SW seven eighty.
- 32:46These are our genes. These
- 32:47are our luminal genes. These
- 32:49are our basal genes.
- 32:51And so you can see
- 32:52here that, you know, with
- 32:53the knockouts, these are the
- 32:54knockouts here, these are the
- 32:55wild types. We see this
- 32:57increased expression
- 32:58in basal genes consistently. I
- 33:00mean, sorry. These are the,
- 33:01these are interferon gamma treated.
- 33:03I apologize. So control interferon
- 33:05gamma treated. You see this
- 33:06increased expression
- 33:08of the the basal genes,
- 33:10including the molecular the, you
- 33:12know, keratin six, you know,
- 33:13keratin fourteen, these high molecular
- 33:15weight keratin. It's not just
- 33:16the inflammatory things. It's the
- 33:17epithelial things as well that
- 33:19are going up.
- 33:21And so we also, you
- 33:23know, looked at centroid analysis
- 33:24similar to we did in
- 33:25that that,
- 33:26study where we turned luminal
- 33:28cell lines into basal cell
- 33:29lines.
- 33:30So here's control, here's interferon
- 33:32gamma treatment.
- 33:33This is showing the correlation
- 33:34of the basal centroid. So
- 33:36that means with centroid analysis,
- 33:38our sequencing data, the higher
- 33:39it is, the the more
- 33:41the more basalts becoming, the
- 33:42closer it's getting to that
- 33:43basal centroid.
- 33:46And so with each one
- 33:47of them, they got a
- 33:47little they got closer to
- 33:48that basal centroid and two
- 33:49of the threes flipped flipped.
- 33:51Meaning, they got closer to
- 33:53the basal centroid than the
- 33:54they were to the luminal
- 33:55centroid. And those two were,
- 33:57UMBC one and RT one
- 33:59one two, whereas the SW
- 34:00seven eighty cell line didn't
- 34:01flip, but it just got
- 34:02closer.
- 34:04And similarly,
- 34:06you know, the interferon dominant,
- 34:07we also put these in
- 34:08the inflammatory
- 34:09thoresen subtypes. And, you know,
- 34:10totally as you'd expect they'd
- 34:12be. They got much much
- 34:13more of this interferon gamma
- 34:14dominant,
- 34:15subtype.
- 34:16So that was interesting. So
- 34:17interferon gamma appeared to be
- 34:19driving the basal. It wasn't
- 34:20just that if you knock
- 34:21out FOXA1, it becomes more
- 34:22interferon gamma dominant. There's there's
- 34:24a loop here. There's some
- 34:25kind of a feedback mechanism
- 34:27going on.
- 34:29Then we thought, well, maybe
- 34:30we could do the opposite.
- 34:32So,
- 34:33what if we take basal
- 34:34cell lines and we inhibit
- 34:36interferon gamma signaling?
- 34:38So we did, we took,
- 34:40the basal cell line stabber,
- 34:42which is a well established
- 34:43bladder cancer basal cell line,
- 34:45and we treated it with
- 34:46the the JAK inhibitor ruxolitinib.
- 34:48Ruxolitinib is it's a relatively
- 34:50new drug. It's used to
- 34:51treat myelofibrosis,
- 34:52a couple other heme diseases.
- 34:54It's a pan JAK inhibitor
- 34:56and it's JAK one and
- 34:56JAK two, and those are
- 34:58the receptor tyrosine kinases that
- 34:59carry out interfering gamma signaling.
- 35:02So we can treat it
- 35:03as an interfering gamma inhibitor.
- 35:05And so whenever we treated
- 35:06the basal cell lines GABA
- 35:07with the JAK inhibitor,
- 35:09it didn't flip all the
- 35:10way to luminol, but it
- 35:12became more luminol.
- 35:13So it it lowered expression
- 35:15of basal genes and it
- 35:16increased expression of of, luminal
- 35:18genes. So we've got here
- 35:19is our ruxolitinib treated group,
- 35:22our,
- 35:23control group. Here are our
- 35:25genes. Here are our basal
- 35:26genes. Here are our luminal
- 35:27genes. And you can see
- 35:29that whenever you're treated with
- 35:30ruxolitinib,
- 35:32the ex
- 35:33expression of the
- 35:35the the luminal genes went
- 35:36up pretty substantially.
- 35:38Not only to flip it
- 35:39because these SCABER cell lines,
- 35:41they're whenever you grow these
- 35:42things in xenografts, they're making
- 35:43keratin. They are very, very
- 35:45basal bladder cancers. Even those,
- 35:47we are able to to
- 35:48push more in in the
- 35:50luminal direction with ruxolitinib.
- 35:53And you'll notice among these
- 35:54luminal genes, FOXA1 went up,
- 35:57GATA3 went up, and PPAR
- 35:58gamma largely went up. And
- 36:00you'll recall those are the
- 36:01three that we used to
- 36:03drive the basal cell line
- 36:05to a liminal liminal type.
- 36:08And, you know, as expected,
- 36:09we we also looked at
- 36:11this, these these inflammatory
- 36:13subtypes, the thoras and ones,
- 36:14and we really diminished the
- 36:16the the, probability of a
- 36:18interferon gamma, you know, inflammatory
- 36:20subtype.
- 36:25So, so in summary,
- 36:27you know, I think that
- 36:29with the evidence we've collected,
- 36:30you know, bladder cancer is
- 36:32phenotypically diverse, we can know
- 36:33this, and it's likely a
- 36:35result of lineage plasticity. It's
- 36:36not that they're just born
- 36:37one way or the other.
- 36:38It's a plastic process that
- 36:39starts off probably from stuff
- 36:41that's differentiated toward urothelium.
- 36:44And then that lineage plasticity
- 36:45toward the basal phenotype appears
- 36:46driven by interferons
- 36:48or interferon gamma, whereas,
- 36:50differentiation toward the liminal phenotype
- 36:52appears to be driven by
- 36:53by these these key transcription
- 36:55factors.
- 36:57And that is all I
- 36:58have to say.
- 36:59Thank you. Happy to take
- 37:01questions.
- 37:09Yeah. Go ahead. I have
- 37:11two questions. Yes.
- 37:29Yes. No. So it was
- 37:31it's just kind of a
- 37:31theoretical,
- 37:32you know, precursor, so I
- 37:34can I can go back?
- 37:38Yeah. So it was like
- 37:41Yes. Yeah. So this one.
- 37:42So,
- 37:43you know, we we sequence
- 37:44both. These are part of
- 37:45the same tumor. So think
- 37:46of this as a tumor.
- 37:47You know, one area squamous,
- 37:48one area is epithelial.
- 37:50And so spatially distinct parts
- 37:51of the same physical mass,
- 37:54and we sequenced them. And
- 37:55so this dot here indicates,
- 37:58the the common precursor. You
- 38:00know, think of this like
- 38:01an evolutionary phylogeny.
- 38:03This would be the the
- 38:04the common ancestor of the
- 38:05two, and we can say
- 38:06it's the common ancestor because
- 38:07it shares the key driver
- 38:08mutations. And then this thing
- 38:10is, we just added that
- 38:11so you'd have, like, you
- 38:12know, some idea of, like,
- 38:13you know, the cell from
- 38:14which they both arose. It's
- 38:15more like eye candy. It
- 38:16really doesn't, you know, add
- 38:18much to the meaning of
- 38:19the figure.
- 38:33So this this was the
- 38:34biopsy. So those were, either
- 38:36metastatic or locally advanced, urothelial
- 38:39carcinoma that that we were
- 38:40looking at. So these would
- 38:41have been biopsies from
- 38:43it it they weren't super
- 38:45strict in terms of the
- 38:46histology that was required,
- 38:48but it was just some
- 38:49kind of biopsy demonstrating that
- 38:50was either locally advanced or
- 38:52or a metastatic disease.
- 38:54And you can't file with
- 38:55the GHAH and E even
- 38:57for our own Even from
- 38:58that. Yep.
- 39:04Anyone else?
- 39:06Excellent.
- 39:07Okay.
- 39:09So I have a question
- 39:09about your diagram.
- 39:19There is, but you you
- 39:20gotta draw the line somewhere.
- 39:23Yeah. So it's
- 39:24we we just pick these
- 39:25as kinda like to illustrate
- 39:26because their genes that that
- 39:27are important or are well
- 39:29known.
- 39:30But it was it's kind
- 39:31of amazing. Like, some of
- 39:32these cases, they were they
- 39:33were more different than they
- 39:34were similar.
- 39:36In some cases, they were
- 39:37more similar than they were
- 39:37different. But, yeah, we just
- 39:39kinda had to, you know,
- 39:39start somewhere, so that's why
- 39:41we we limited it. It's
- 39:42easy to find the current
- 39:44Mhmm. And then being on
- 39:45as one week.
- 39:51Yeah. Yeah. I mean and,
- 39:51well, I think, you know,
- 39:52it it
- 39:53possibly informing new biology.
- 39:56Because, you know, like, for
- 39:57example, this one, the TP
- 39:58fifty three, gene mutation was
- 40:00was private to the squamous
- 40:01part. And, you know, squamous
- 40:03is thought to be more
- 40:03aggressive, and I guess that
- 40:04makes sense.
- 40:06But, you know, in this
- 40:06one, the TP fifty three
- 40:08gene mutation and in this
- 40:09one, it was it was
- 40:10common to both. So it's
- 40:11it's really hard. I I
- 40:12think one of the things
- 40:13we've learned from the past
- 40:14ten years is that it's
- 40:15very hard to identify, you
- 40:17know, key driver mutations
- 40:19that are responsible
- 40:20or relate to squamous histology.
- 40:22It really seems to be
- 40:23more of a, you know,
- 40:24a transcriptional
- 40:25process than it is a
- 40:26mutation driven process, if you
- 40:28will.
- 40:31So I have a question.
- 40:33You know, why we we
- 40:35validate
- 40:36that
- 41:31Yeah. So it's it's a
- 41:32great question and much,
- 41:34there's been a lot of
- 41:34conversation about this in the
- 41:35bladder cancer world, a lot
- 41:37of lot of ink spilled
- 41:38or, you know, virtual ink
- 41:39spilled out on the topic.
- 41:40And so,
- 41:42one of the things that's
- 41:43popped out is that
- 41:45it's very difficult to create
- 41:47reliable
- 41:48categorical
- 41:49tests
- 41:50for basal versus luminal.
- 41:52And I think it relates
- 41:53to, you know, us showing
- 41:54this as a, a it's
- 41:56not a categorical variable. Truly,
- 41:57it's a it's a continuous
- 41:59variable. And so I think
- 42:00one of the the best
- 42:01stories well, not best stories,
- 42:02but one of the most
- 42:03telling stories,
- 42:04is with the DECIPHER bladder
- 42:06cancer test. So decipher bladder
- 42:08cancer test was something that
- 42:09was, marketed,
- 42:12I believe it was even
- 42:13FDA approved.
- 42:14I don't remember. I have
- 42:15to look that up, but
- 42:16it was marketed,
- 42:17to to assign molecular subtypes
- 42:19to muscle invasive bladder cancer
- 42:21to to decide if it's
- 42:23going to be,
- 42:24responsive to neoadjuvant cisplatin based
- 42:26chemotherapy, which is the standard.
- 42:28And they showed that,
- 42:31the their their basal subtype
- 42:33had better response than their
- 42:34non basal sub subtype. So
- 42:36they were they were advocating
- 42:37using this to make this
- 42:38key clinical decision, and that
- 42:40was the decipher group.
- 42:42Then the the Lund group
- 42:43I told you about came
- 42:44out with another project that
- 42:46was very large and very
- 42:47well done.
- 42:49It showed the opposite. They
- 42:50said that the basal group
- 42:52was resistant to neoadjuvant chemotherapy
- 42:54and their genomically unstable group
- 42:56was more sensitive.
- 42:58And so then there's another,
- 43:00then someone's like, what is
- 43:01going on here? So,
- 43:03forget what the what group
- 43:04it was, but they basically,
- 43:05they took some cancers and
- 43:06they sent them out for
- 43:07decipher and got them profiled.
- 43:09Then they did the lung
- 43:10classification,
- 43:11and they were all over
- 43:12the place. So there was
- 43:13there was an overlap.
- 43:15The basils from one didn't
- 43:16overlap with the the basils
- 43:17from the other.
- 43:19And so the I think
- 43:21that goes to the tell
- 43:22the story, like, whenever we
- 43:23say basilar, we say luminal,
- 43:24we're saying something that's somewhat
- 43:26arbitrary.
- 43:27Who's basal? Who's luminal?
- 43:29There's there's
- 43:31there really, I think that
- 43:32the way to do this
- 43:32isn't to say this is
- 43:33a luminal cancer or basal
- 43:34cancer, but rather, what are
- 43:36the processes?
- 43:37What are the signatures that
- 43:38are active and how can
- 43:39we use those to inform
- 43:41therapy?
- 43:42So at this point, I'm
- 43:43I really am not an
- 43:44advocate at all of the
- 43:45descending molecular subtypes,
- 43:47in the clinical setting. I
- 43:47think there's no we don't
- 43:49know how to do it,
- 43:50basically, and we don't know
- 43:51what to do with the
- 43:51information once we get it.
- 44:04Yeah.
- 44:06So with those
- 44:08with the base of our
- 44:23Yeah.
- 44:31So I don't know if
- 44:32anyone who's looked at the
- 44:33basal phenotype of noninvasive papillary
- 44:35cancers. I would assume they're
- 44:36high grade, but I I
- 44:37don't know that.
- 44:38But people have looked at
- 44:40the subtype of these, the
- 44:41flat carcinoma in situ, and
- 44:42there is a subset of
- 44:43those. There's a small subset
- 44:44of flat carcinoma in situ
- 44:45that has a basal phenotype,
- 44:47and that's more aggressive. That's
- 44:48associated with higher risk of
- 44:49progression to muscle invasion, etcetera.
- 44:51So, so it's not completely
- 44:53false that there's like this
- 44:54subset that start off basal.
- 44:55I just think it's a
- 44:56minority of them that do.
- 45:00Anyone else?
- 45:01Oh, yes. So the, a
- 45:03lot of us working on,
- 45:05cell lines. Yes. And and
- 45:06the,
- 45:07the prototypical aluminum cell lines
- 45:10and for physical
- 45:12cell lines,
- 45:22Yeah. They do. It it's
- 45:24kind of amazing, actually. Oh,
- 45:25did you have more? Go
- 45:26ahead. Go ahead. I can
- 45:27explain.
- 45:39So we haven't done the
- 45:40latter yet, but but the
- 45:42the former question, yes. So
- 45:43some of these
- 45:44do have similar histologies.
- 45:47It's it's difficult to to
- 45:48really compare them. And the
- 45:50way that we've done it
- 45:51historically is is with xenograft.
- 45:53So if you grow, like,
- 45:54the the cell in r
- 45:54t four, for example, which
- 45:55is a liminal cell line
- 45:57in a subcapsular,
- 45:59you know, kidney xenograft
- 46:01in skin mice. It looks
- 46:02like a papillary carcinoma, classic,
- 46:04you know, papillary or theeloid
- 46:06carcinoma. You grow a SCABER
- 46:07cell line. It's a basal
- 46:08one in the same model.
- 46:09Even a subcutaneous xenograft, it's
- 46:11keratinizing squamous cell cancer. So
- 46:12the the histology does mirror
- 46:14the molecular subtype very well.
- 46:17But they're they're hard to
- 46:18grow. Like, not every all
- 46:19all these cell lines grow
- 46:20easily in xenograft, some just
- 46:22don't.
- 46:23And so we've we've not
- 46:24done that experiment, but that's
- 46:25it's a
- 46:27yeah, that's it's something I
- 46:28thought about, but I've not
- 46:29done it. They don't have
- 46:30the state. It it's not
- 46:32that impressive. So in culture,
- 46:33yeah, like, the the r
- 46:34t fours are kinda like
- 46:35little little dots. They're little
- 46:36papillary looking things, but nothing
- 46:38is impressive as the xenografts.
- 46:39But it really doesn't change
- 46:41the just, like, the
- 46:42the, you know,
- 46:44the look of the cell
- 46:45lines. So it suggests that
- 46:46maybe some
- 46:47of
- 46:48the morphologic,
- 46:49histologic
- 46:50Mhmm. Is
- 46:51derived from interactions from the
- 46:53others. Yeah.
- 46:55Yes. Yeah.
- 46:56For sure.
- 46:59Yeah. Go ahead.
- 47:16Yes. So,
- 47:17we
- 47:18actually, I've I Andrew, I
- 47:19just analyzed your data he
- 47:20gave me, and so we
- 47:21actually have some of this
- 47:22we're looking at right now.
- 47:24They're they appear to be
- 47:25more basal in our hands
- 47:26at least.
- 47:27But in the hands of
- 47:28others who have published on
- 47:29this,
- 47:30it it's it's
- 47:32inconsistent. And it's it's a
- 47:33similar kind of story that
- 47:34if you look at spatially
- 47:35distinct parts of a tumor,
- 47:36you get different subtypes. If
- 47:38you also look at the
- 47:38lymph node metastasis or distant
- 47:40metastasis, it it can differ,
- 47:42from the primary as well.
- 47:43So it really it's what
- 47:44part of the main tumor,
- 47:45you know, gave rise to
- 47:46the MET.
- 47:52Alright. No one else?
- 47:54Oh oh, yeah. Go ahead.
- 47:56Just in general, you found
- 47:58lung classification that was reproducible.
- 48:01I I don't think any
- 48:02of them are that reproducible.
- 48:03I think that it just
- 48:04I mean, they're reproducible on
- 48:06their own.
- 48:07In the lung classification is
- 48:08nice because they have got
- 48:09some some biological,
- 48:11you know
- 48:13you know, consistency to it.
- 48:14So, you know, like, their
- 48:15lumenal types, there's two of
- 48:16them and they're they classify
- 48:17them based on the cell
- 48:18cycle gene that's been knocked
- 48:19out.
- 48:21But I don't I don't
- 48:22wanna use the word consistent.
- 48:23I think they're all consistent
- 48:23with themselves, but they're just
- 48:24not consistent with each other
- 48:25because it depends on the
- 48:26genes you pick to put
- 48:28them in the different groups,
- 48:29and they can be, a
- 48:30little inconsistent based on that.
- 48:35Alright. Well, thank you all.