Welcome to the Clinical Center Grand Rounds, a weekly series of educational lectures for physicians and health care professionals broadcast from the Clinical Center at the National Institutes of Health in Bethesda, MD. The NIH Clinical Center is the world's largest hospital totally dedicated to investigational research and leads the global effort in training today's investigators and discovering tomorrow's cures. Learn more by visiting us online https://clinicalcenter.nih.gov WE WELCOME TWO COLLEAGUES FROM THE NATIONAL INSTITUTE ON DEAFNESS AND OTHER COMMUNICATION DISORDERS ADDRESSING WHO CONDITIONS, CLINICALLY IMPORTANT, RELATIVELY COMMON IN MEDICAL PRACTICE, SPECIFICALLY CHEMOTHERAPY-INDUCED HEARING LOSS AND STUTTERING. OUR FIRST SPEAKER IS DR. LISA CUNNINGHAM, SENIOR INVESTIGATOR AND CHIEF OF SECTION ON SENSORY CELL BIOLOGY, CLEATED TRAINING AS CLINICAL AUDIOLOGIST BEFORE OBTAINING Ph.D. IN UNIVERSITY OF VIRGINIA, COMPLETED A POSTDOCTORAL RESEARCH FELLOWSHIP IN AUDITOY NEUROSCIENCE AT THE UNIVERSITY OF WASHINGTON IN SEATTLE. SHE BEGAN HER ACADEMIC CAREER AS ASSISTANT PROFESSOR AT MEDICAL UNIVERSITY OF SOUTH CAROLINA, PRIOR TO JOINING THE NIH AS TENURE-TRACK INVESTIGATOR, IN 2011. CURRENTLY HER LABORATORY CONDUCTED BASIC, TRANSLATIONAL AND CLINICAL STUDIES ON ACQUIRED HEARING LOSS. HER RESEARCH INTERESTS INCLUDE THE ELUCIDATION OF THE CELLULAR AND MOLECULAR MECHANISMS ACTIVATED WHEN SENSORY HAIR CELLS IN THE INNER EAR ARE UNDER STRESS, AND CLINICAL INTERVENTIONS AIMED AT PREVENTING OR REVERSING HEARING LOSS IN HUMANS. DR. CUNNINGHAM SERVES AS A COUNCIL MEMBER AT LARGE FOR ASSOCIATION FOR RESEARCH IN OTOLARYNGOLOGY, AND SHE'S A MEMBER OF THE EDITORIAL BOARD OF THE JOURNAL HEARING RESEARCH. SECOND SPEAKER IS DR. DENNIS DRAYNA, SENIOR INVESTIGATOR, CHIEF OF SECTION ON SYSTEMS BIOLOGY OF COMMUNICATION DISORDERS IN THE LABORATORY OF COMMUNICATION DISORDERS AT NIDCD. DR. Ph.D. FROM HARVARD, FELLOWSHIP AT HOWARD HUGHES MEDICAL INSTITUTE AT UNIVERSITY OF UTAH. AT UTAH HE CONSTRUCTED THE FIRST FULL LENGTH GENETIC MAP OF A HUMAN X CHROMOSOME AND DISEASE-SPECIFIC GENE LINKAGE STUDIES, SUBSEQUENTLY SPENT 15 YEARS IN THE BIOTECHNOLOGY INDUSTRY, WHERE HE WORKED ON GENETIC ASPECTS OF CHOLESTEROL AND LIPID METABOLISM AND IDENTIFIED THE GENE RESPONSIBLE FOR HEREDITARY HEMOCHROMATOSIS. EASY FOR ME TO SAY, RIGHT? IN 1996, HE MOVED TO THE NIH AS A VISITING INVESTIGATOR AT THE NATIONAL HUMAN GENOME INSTITUTE, N OF IN 1997 HE WORKED ON GENETICS OF DISORDERS SUCH AS AUDITORY PITCH PERCEPTION, AND SENSE OF TASTE, AND DISORDERS OF VOICE AND SPEECH. HIS CURRENT RESEARCH IS DIRECTED AT UNDERSTANDING THE GENETICS OF STUTTERING AND IDENTIFICATION OF NEURAL DEFICITS THAT UNDERLIE THIS DISORDER ADJUNCT PROFESSOR OF NEUROSCIENCE AND COGNITIVE SCIENCE, UNIVERSITY OF MARYLAND, 18 U.S. PATENTS, AMERICAN SOCIETY OF HUMAN GENE ETHICS AND ADVANCEMENT OF SCIENCE, VICE PRESIDENT OF STUTTERING FOUNDATION OF AMERICA, AND MEMBER OF THE EDITORIAL BOARD OF THE JOURNAL, CHEMICAL SENSE. LET'S BEGIN BY WELCOMING DR. CUNNINGHAM TO THE PODIUM. >> THANK YOU FOR THE INTRODUCTION AND OPPORTUNITY TO TALK ABOUT STUDIES ON HEARING LOSS CAUSED BY THE ANTI-CANCER DRUG CISPLATIN. IN TERMS OF DISCLOSURES, I INTEND TO DESCRIBE A POTENTIAL OFF LABEL USE OF FDA APPROVED DRUGS. SO, THIS IS THE ANTI-CANCER DRUG CISPLATIN, THE CORE OF THE MOLECULE OF PLATINUM ATOM, AS YOU CAN SEE. HIS PROBABLY THE MOST WIDELY USED AND SUCCESSFUL ANTI-CANCER DRUG IN THE WORLD, CLINICAL USE SINCE THE '60s. IT IS ALSO THE MOST OTOTOXIC DRUG IN CLINICAL USE, EAR AND POISON USE. IT'S TYPICALLY BILATERAL, SYMMETRICAL IN MOST CASES, SENSORY AND IT IS PERMANENT. WE CURRENTLY CANNOT REVERSE CISPLATIN-INDUCED HEARING LOSS. THIS HEARING LOSS APPEARS IN FIRST IN HIGH FREQUENCY, WITH INCREASED DOSED OR CONTINUED USE CAN PROGRESS TO LOWER FREQUENCY. TIME IS GRADUAL, PROGRESSIVE AND CUMULATIVE. SOMETIMES YEARS AFTER DISCONTINUATION OF CISPLATIN THERAPY, ESPECIALLY TRUE IN CHILDREN TREATED WITH CISPLAIN. SO, A LITTLE BIT OF INTRODUCTION ADULTS, INCIDENCE DATA IN VARIOUS CANCERS, YOU CAN SEE THAT FOR EXAMPLE IN HEAD AND NECK CANCER AT LEAST HALF OF ADULTS TREATED WITH CISPLATIN FOR HEAD AND NECK CANCER HAVE A PERMANENT CLINICALLY SIGNIFICANT HEARING LOSS. THE INCIDENCE IS ROUGHLY 60 TO 70% OF PATIENTS WITH TESTICULAR CANCER, 25 TO 50% OF PATIENTS WITH LUNG CANCER TREATED WITH CISPLATIN SO THE INCIDENCE IS PRETTY HIGH AMONG THESE CANCER SURVIVORS. AND VARIOUS FACTORS INFLUENCE SUSCEPTIBILITY OF A GIVEN PATIENT TO CISPLATIN-INDUCED HEARING LOSS. CONCURRENT CRANIAL RADIATION FOR EXAMPLE IN CASE OF HANDY NECK CANCER WILL INCREASE THE SUSCEPTIBILITY TO CISPLATIN-INDUCED HEARING LOSS, AS WELL AS PREVIOUS HEARING LOSS. A THIRD OF CHILDREN WITH CANCER RECEIVE CISPLATIN THERAPY, HALF GET A PERMANENT HEARING LOSS. AGAIN, HERE ARE SOME DATA ON THE INCIDENCE OF CISPLATIN-INDUCED HEARING LOSS IN CHILDREN, 50% OF CHILDREN WITH OSTEOSARCOMA, HIGHER WITH HEPATOBLASS HEPATOBLASSTOMA. FOR ALL CANCERS COMBINED YOU CAN SEE THERE'S A HIGH INCIDENCE OF CISPLATIN-INDUCED HEARING LOSS IN CHILDREN, MORE SEVERE CISPLATIN-INDUCED HEARING LOSS IN CHILDREN. FACTORS THAT INFLUENCE SUSCEPTIBILITY OF CHILDREN TO GET A HEARING LOSS ARE THE AGE, CHILDREN UNDER 5 YEARS OLD ARE MORE SUSCEPTIBLE THAN CHILDREN WHO ARE OLDER THAN 5. THE DOSE CONTRIBUTES TO SUSCEPTIBILITY, CONCURRENT CRANIAL IRRADIATION. IN CHILDREN WE SEE COMBINED OTOTOXIC EFFECT, PARTICULARLY INCLUDING THE OTHER MAJOR CLASS OF OTOTOXICS DRUG, IMMUNOGLYCOCIDE ANTIBIOTICS. THESE ARE THE CELLS THAT CONVERT SOUND ENERGY INTO NEURAL INPUT TO THE BRAIN. CISPLATIN KILLS THESE CELLS AND SURROUNDING GLIA-LIKE CELLS THAT PROCEED TROPIC SUPPORT TO THE HEARING CELLS AND KILLS NEURONS WHICH WE LAY TO THE BRAIN. WE SEE DEATH OF CELLS ON THE LATERAL WALL OF THE INNER EAR, PROVIDING THE BLOOD SUPPLY AND NUTRIENT SUPPORT TO IT INNER EAR. CISPLATIN DAMAGES ALL THESE CELL TYPES IN THE INNER EAR. WE WANTED TO EXAMINE WHY, SINCE ADMINISTERED SYSTEMICALLY, INNER EAR IS UNIQUELY SUSCEPTIBLE. A STUDENT GRADUATED FROM OUR LAB AND HYPOTHESIZED PHARMACOKINETICS MAY CONTRIBUTE TO CAN CISPLATIN-INDUCED DAMAGE. IN ORDER TO TEST, ANDREW DEVELOPED A MOUSE MODEL, PRIOR TO DEVELOPMENT MOST PEOPLE WHO WERE WERE STUDYING IN RODENTS USED A SINGLE INJECTION OF A HIGH DOSE, IN MICE WHAT YOU USUALLY GET IS INSTEAD OF A HEARING LOSS IS A DEAD MOUSE. THAT PROTOCOL WASN'T USEFUL TO US. ALSO THAT KIND OF SINGLE INJECTION PROTOCOL DOESN'T REFLECT HOW CISPLATIN IS INDUCED CLINICALLY, WITH ROUNDS, SEPARATED BY PERIODS OF RECOVERY AND SO WE WANTED TO DEVELOP A MODEL THAT WAS CLINICAL RELEVANT AND SIMILAR IN THAT WAY. SO THE WAY WE DO THESE EXPERIMENTS IS WE TEST THE HEARING OF THE MOUSE USING AUDITORY BRAIN RESPONSE, ADMINISTER THREE CYCLES, FOUR DAYS FOLLOWED BY TEN DAYS OF RECOVERY IN A SINGLE CYCLE. MICE GET THREE CYCLES OF THIS CISPLATIN ADMINISTRATION AND WE TEST HEARING USING AUDITORY ABRAHAM -- BRAINSTEM RESPONSE, THE SAME USED IN THE NEONATAL INTENSIVE CARE UNIT. WHEN WE GIVE THIS PROTOCOL TO MICE THEY GET A SIGNIFICANT PERMANENT HEARING LOSS, SIMILAR TO HUMANS. THIS GRAPH SHOWS THE FREQUENCY RANGE OF NORMAL MOUSE HEARING WHICH IS HIGHER THAN FREQUENCY RANGE OF HUMAN HEARING, THIS IS THRESHOLD SHIFT, HOW MUCH WORSE HEARING WAS IN THE SECOND TEST THAN THE FIRST. SO AS YOU GO UP ON THE GRAPH HEARING LOSS GETS WORSE. SO WHAT YOU CAN SEE IS THAT MICE TREATED WITH SALINE, CONTROL MICE DO NOT GET HEARING LOSS. DEPENDING ON DOSE OF CISPLATIN WE GIVE WE GET INCREASING HIGH FREQUENCY HEARING LOSS THAT GETS WORSE IF WE INCREASE DOSE OF CISPLATIN AND SPREAD TO LOWER FREQUENCIES, CHARACTERISTICS ARE SIMILAR TO THE CISPLATIN OTOTOXIN IN HUMANS THAT RECEIVE CISPLATIN. IN ORDER TO MEASURE CISPLATIN PHARMACOKINETICS ANDREW CORROBORATED WITH LAUREN, EXPERTISE IS METAL OMICS, EFFECTS OF METALS IN THE BODY. THE CORE OF CISPLATIN MOLECULE IS A PLATINUM ATOM, SO LAUREN WAS ABLE TO MEASURE THE AMOUNT OF PLATINUM IN TISSUES AND IT GAVE US A SENSITIVE METHOD TO LOOK AT THIS, BECAUSE NORMAL TISSUES DON'T CONTAIN PLATINUM. THE METHOD LAUREN AND ANDREW USED IS INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY, IN THIS METHOD ARGON IS USED TO GENERATE A PLASMA THAT IS ABOUT THE TEMPERATURE OF THE SUN, AND SO LAUREN EXPLAINS THIS TO ME, SHE NEBULIZES, USES MASS SPECTROMETRY METHOD TO MEASURE HOW MUCH PLATINUM IS IN THE TISSUE. THIS IS A SENSITIVE METHOD TO DETECT AT PARTS PER QUADRILLION. WHAT ANDREW IS IS ADMINISTERED CISPLATIN TO MICE AND COLLECTED TISSUES, HOW MANY PLATINUM WAS IN THE TISSUES. THIS SLIDE REMINDS ME TO TELL YOU NORMAL TISSUES DON'T CONTAIN ANY PLATINUM. SO IN ALL OF THESE VARIOUS TISSUES WE DIDN'T SEE ANY PLATINUM IN MICE THAT DIDN'T RECEIVE ANY CISPLATIN. IN MICE THAT DID RECEIVE CISPLATIN, WE SAW A VERY TYPICAL PATTERN FOR MOST TISSUES. THAT IS WHEN WE WERE ADMINISTERING CISPLATIN LEVELS WENT UP, WHEN WE STOPPED THE PLATINUM LEVELS IN THE TISSUE RAPIDLY DECLINED, INDICATING MOST ARE CAPABLE OF TAKING UP CISPLATIN AND RAPIDLY CLEARING THE CISPLATIN. THIS WAS TRUE OF LIVER AND KIDNEY AND LUNG AND HEART. WE WERE NOT SURPRISED THAT WE DIDN'T SEE CISPLATIN ACCUMULATION IN BRAIN. CISPLATIN DOES NOT READILY CROSS THE BLOOD-BRAIN BARRIER. IT IS TAKEN UP AND RAPIDLY CLEARED FOR MOST TISSUES. WHEN WE LOOKED AT INNER EAR SAW A DIFFERENT PATTERN, CISPLATIN ACCUMULATED IN INNER EAR BUT WHEN STOPPED IT REMAINED STEADY IN INNER EAR AND PROGRESSIVELY ACCUMULATED WITH WITH ADDITIONAL CYCLES, IT ENTERS AND IS POORLY CLEARED. IN WHEN ANDREW LOOKED FOR 60 DAYS BEYOND THE LAST TIME POINT HERE THESE OTHER TISSUES HAD ALL RETURNED TO BASELINE LEVELS OF PLATINUM AND COCHLEA REMAINED STEADY, SUGGESTING IT REMAINS IN THE INNER EAR INDEFINITELY. TO DETERMINE IF TRUE IN HUMANS COLLABORATED WITH NIDCD TEMPORAL BONE BANK, AT THE MASSACHUSETTS EYE AND EAR INFIRM ANY IN BOSTON, PROVIDING SECTIONS OF HUMAN TEMPORAL BONES FROM PATIENTS WHO RECEIVED CISPLATIN THERAPY. AND LAUREN AND ANDREW USED THE SAME MASS SPECTROMETRY METHOD I SHOWED, LAUREN SCRAPED SLIDES INTO THE MASS SPEC MACHINE AND WHAT YOU SEE ON THIS GRAPH IS TIME THAT ELAPSED BETWEEN THE LAST CISPLATIN INFUSION AND TIME OF DEATH. THIS IS THE AMOUNT NORMALIZED TO AMOUNT OF SULPHUR IN THE TISSUE. THE TEMPORAL BONE BANK PROVIDED A FEW PATIENTS' BONE, YOU SEE THREE SECTIONS FROM THE TEMPORAL BONE IN EACH INNER EAR. YOU CAN SEE THAT THE CISPLATIN REMAINED IN THE HUMAN INNER EAR AS LEAST OUT TO 18 MONTHS, THE LATEST PERIOD OF TIME THE TEMPORAL BONE BANK WAS ABLE TO PROVIDE US. SAMPLES HERE ARE FROM ADULT PATIENTS, THE BANK HAD SAMPLES FROM ONE PEDIATRIC PATIENT WHO WAS TREATED WITH CISPLATIN, YOU CAN SEE THOSE DATA HERE. WE KNOW THAT THIS CHILD RECEIVED LESS CISPLATIN THAN ANY ADULTS AND YET WE SEE MORE PLATINUM IN THE INNER EAR THAN WE DO IN ANY OF THE ADULT SAMPLES, CONSISTENT WITH CHILDREN ARE MORE SUSCEPTIBLE TO CISPLATIN INDUCED HEARING LOSS THAN ADULTS. THESE DATA INDICATE THAT CISPLATIN ACCUMULATES IN THE INNER EAR AND IS NOT CLEARED AND IN FACT AS LATE AS WE'VE BEEN ABLE TO LOOK THE PLATINUM LEVELS APPEAR TO REMAIN STABLE SUGGESTING NO WAY TO REMOVE CISPLATIN ONCE IT'S THERE. TRANSLATIONAL INTERPRETATION OF THESE DATA ARE THAT AN APPEALING THERAPEUTIC APPROACH MIGHT BE TO REDUCE UPTAKE IN THE FIRST PLACE. THE INNER EAR NEVER NEEDS CISPLATIN SO THE APPROACH IS TO REDUCE CISPLATIN UPTAKE IN INNER EAR, CURRENTLY WE'RE UNDERTAKING A SCREEN IN COLLABORATION ARE MATTHEW HALL AT NCATS TO LOOK FOR DRUGS THAT DO THAT. I'LL TELL YOU ABOUT ANOTHER TACK WE'VE BEEN TAKING, ARE THERE FDA-APPROVED DRUGS THAT MIGHT PREVENT CISPLATIN-INDUCED HEARING LOSS. IF THERE IS A DRUG THAT HAS A GOOD SAFETY PROFILE IN HUMANS AND THAT DRUG REDUCES CISPLATIN-INDUCED HEARING LOSS WE MIGHT BE ABLE TO HAVE SOME RAPID TRANSLATION OF OF THAT DRUG INTO CLINICAL USE TO PROTECT THE HEARING OF CANCER PATIENTS UNDERGOING CISPLATIN THERAPY. SO, THE CLASS OF DRUGS WE'RE INTERESTED IN ARE THESE CHOLESTEROL LOWERING DRUGS, STATINS, THE REASONS ARE THAT STATINS ARE KNOWN INDUCERS OF HEME OXYGENASE 1, IN ADDITION THERE IS OTHER EVIDENCE IN THE LITERATURE THIS IS NOT DATA FROM OUR LAB THAT THESE ARE STUDIES THAT SUGGEST THAT STATINS ARE PROTECTIVE IN OTHER MODELS OF HEARING LOSS IN ANIMALS. SO OUR HYPOTHESIS WAS STATINS WOULD BE PROTECTIVE AGAINST CISPLATIN-INDUCED HEARING LOSS IN BOTH RODENTS AND HUMANS. SO KATE FERNANDEZ, STAFF SCIENTIST IN OUR LAB, SPENT TWO YEARS LOOKING FOR DATA ON AUDIOGRAMS OF PATIENTS WHO HAD UNDERGONE CISPLATIN THERAPY AND THIS IS WHERE WE RAN INTO A HUGE ROAD BLOCK. THE CHALLENGE THAT WE HAD IS THAT WHILE MOST -- VIRTUALLY ALL CHILDREN GOING TO UNDERGO CISPLATIN THERAPY RECEIVE A BASELINE HEARING TEST, VIRTUALLY NO ADULTS DO, WHEN THEY ARE ABOUT TO UNDERGO CISPLATIN THERAPY. SO ADULTS USUALLY DON'T RECEIVE A HEARING TEST UNLESS THEY SAY I'M GETTING A HEARING LOSS, FOR US THAT MAKES IT HARD TO MEASURE A CISPLATIN INDUCED HEARING LOSS BECAUSE OF EXISTING LOSS. KATE LOOKED AT DATABASES, AND FOUND A FEW POCKETS OF RELEVANT DATA. SHE HAS COLLABORATED WITH THE UNIVERSITY OF ROCHESTER MEDICAL CENTER, WITH A ROBUST OTOTOXICITY MONITORING PROGRAM FOR THEIR PATIENTS WITH HEAD AND NECK CANCER, AND WALTER REED NATIONAL MILITARY MEDICAL CENTER WHICH HAS A ROBUST MONITORING PROGRAM. WORKING WITH THESE TWO ORGANIZATIONS KATE HAS CONDUCTED A RETROSPECTIVE STUDY OF DATA THEY PROVIDED US. THOSE DATA ARE SUMMARIZED HERE. SO, SO FAR WE HAVE RELEVANT DATA, PRE AND POST, ON 118 ADULTS WITH HEAD AND NECK CANCER. 50% OF THEM ARE STATIN USERS, IN THIS AREA, ABOUT 50 PHYSICAL OF ADULTS WITH HEAD AND NECK CANCER IN THIS AGE GROUP, A GOOD AGE GROUP TO LOOK FOR STATIN USERS, COMMON AMONG 60 TO 70-YEAR-OLD MALES WHO TEND TO BE STATIN USERS. SO, THESE ARE THE DEMOGRAPHIC DATA FROM THE RETROSPECTIVE STUDY THAT KATE IS CONDUCTING, AND THESE ARE SOME DATA ON DIFFERENT METHODS OF MEASURING A CLINICAL RELEVANT HEARING LOSS, THE SPEECH ASSOCIATION AND GROUP WHO GENERATED AN OTOTOXICITY MONITORING PROGRAM HAVE DEVELOPED METHODS OF DETERMINING IF HEARING LOSS IS CLINICAL RELEVANT. SO THIS IS OUR METRIC FOR CLINICAL RELEVANCE, CLINICALLY IMPORTANT. THE STUDY WITH THIS HEARINGIN LOSS. YOU CAN SEE THAT THE NON-STATIN USERS HAVE HIGHER INCIDENCE OF HEARING LOSS THAN DO THE STATIN USERS BY BOTH OF THESE METRICS. AND WHEN WE LOOK ACROSS THE FREQUENCIES BEING MEASURED, WE CAN SEE THAT FOR MOST FREQUENCIES THE STATIN USERS HAVE LESS HEARING LOSS THAN NON-STATIN USERS IN THIS RETROSPECTIVE STUDY. I'VE MARKED THIS AS WORK IN PROGRESS BECAUSE WE'RE 118 RELEVANT RECORDS IN THIS RETROSPECTIVE STUDY, STATISTICALLY WE NEED 300 PATIENT RECORDS, IN ORDER TO DETERMINE IF STATINS REDUCE CISPLATIN-INDUCED HEARING LOSS AND AS I INDICATED EARLIER WE'RE HAVING TROUBLE FINDING RELEVANT RECORDS. IN THE MEANTIME, KATE HAS INITIATE A PROSPECTIVE STUDY WITH DR. NIKKI SCHMIDT, A HEAD AND NECK SURGEON HERE AT HOPKINS, AND KATE FERNANDEZ, A SCIENTIST WHO WORKS IN OUR LAB. AND SO DR. SCHMIDT'S PATIENTS SLATED TO UNDERGO CISPLATIN THERAPY ARE HAVING HEARING TESTS PRIOR TO THE ONSET OF CISPLATIN THEIR AND AFTER THE CESSATION USING A SELF- ADMINISTERED HEARING TEST ON AN iPAD, WE CAN ADMINISTER THIS IN ANY QUIET ROOM AND DOESN'T REQUIRE AUDIOLOGY APPOINTMENT, CONVENIENT FOR CLINICIANS AND FOR OUR PATIENTS. SO IF ANYONE IS INTERESTED IN THIS STUDY OR YOU HAVE PATIENTS INTERESTED IN PARTICIPATING IN THIS STUDY CONTACT ME OR KATE, OR DR. SCHMIDT AND CLINICAL TRIALS IDENTIFIER IS HERE. SO, THAT IS WHAT I WANTED TO TELL YOU ABOUT WORK IN OUR LAB. TWO IMPORTANT STUDIES FROM OTHER GROUPS ARE IMPORTANT IN ANY DISCUSSION OF CISPLATIN-INDUCED HEARING LOSS, FIRST STUDIES PUBLISHED IN 2017 BY THE CHILDREN'S ONCOLOGY GROUP, A CONSORTIUM THAT UNDERTAKES MOST STUDIES OF CANCER IN CHILDREN, IN THE UNITED STATES. IN THIS PARTICULAR STUDY THEY HAD 104 PARTICIPANTS AT 38 SITES IN THE U.S., ALL NEWLY DIAGNOSED WITH CANCER IN THIS STUDY ALL CANCERS, NOT A PARTICULAR CANCER THEY WERE LOOKING FOR. CHILDREN RANDOMIZED TO STS OR OBSERVATION, AND SO STS IS A THIOL-CONTAINING DRUG TO TREAT CYANIDE POISONING, SHOWN IN ANIMALS TO REDUCE CISPLATIN-INDUCED HEARING LOSS. SO, THE ENDPOINT, THE CHILDREN WERE ADMINISTERED STS 6 HOURS AFTER CISPLATIN, WE KNOW STS WILL INACTIVATE CISPLATIN, THEY NEEDED TO SEPARATE IN TIME THE ADMINISTRATION OF THE CISPLATIN AND ADMINISTRATION OF DRUG THEY WERE GOING TO USE TO PROTECT THE INNER EAR. SO THEY HAVE SHOWN IN ANIMALS THAT IF THEY SEPARATE THIS BY 6 HOURS IN TIME, THERE'S NO REJECTION IN THE THERAPEUTIC EFFICACY OF CISPLATIN, A CRITICAL CONSIDERATION IN THESE STUDIES. SO, HEARING LOSS IN CHILDREN TAKING STS WAS 28%, AND 56% IN OBSERVATION GROUP. SO THIS WAS A STATISTICALLY SIGNIFICANT DIFFERENCE. THEY DIDN'T SEE ANY DIFFERENCE IN EVENT-FREE OR OVERALL SURVIVAL, CONDUCTED ANALYSIS THAT SUGGESTED STS MIGHT REDUCE EVENT-FREE SURVIVAL AND OVERALL SURVIVAL IN PATIENTS WITH DISSEMINATED DISEASE BUT DID NOT SEE WITH LOCALIZED DISEASE, PROMISING IN THAT IT SUGGESTED THAT CISPLATIN-INDUCED HEARING LOSS CAN BE REDUCE THE BY USING STS BUT ALSO RAISED A RED FLAG IS THERE A POSSIBILITY THAT THE STS REDUCES THE THERAPEUTIC EFFICACY OF CISPLATIN. SO, A MORE RECENT STUDY THAT CAME OUT OF THE EUROPEAN EQUIVALENT OF THE CHILDREN'S ONCOLOGY GROUP WAS PUBLISHED LAST YEAR IN NEW ENGLAND JOURNAL OF MEDICINE, 116 PATIENTS AT 52 SITES, CAME CANCER. RANDOMIZED TO STS OR OBSERVATION. THEY RECEIVED THE STS 6 HOURS AFTER EACH CISPLATIN DOSE. IN THIS STUDY, THEY HAD HEARING LOSS, 33% IN CHILDREN WHO RECEIVED STS, AND 63% IN CHILDREN WHO DID NOT RECEIVE STS SO HIGHLY STATISTICALLY SIGNIFICAT, AND A NUMBER OF THESE CHILDREN WERE ABLE TO GO ON AND HAVE NORMAL HEARING AFTER THEIR LIVES WERE SAVED BY THIS CISPLATIN DRUG. IMPORTANTLY, THEY SAW NO DIFFERENCE IN SURVIVAL. THIS IS, AGAIN, PROMISING STUDY THAT WE MIGHT BE ABLE TO ADDRESS THIS SIDE EFFECT THAT CAN AFFECT THE LANGUAGE LEARNING ABILITY AND SOCIAL DEVELOPMENT OF THESE CHILDREN WHO ARE UNDERGOING CISPLATIN THERAPY. SO, TO SUMMARIZE, I TOLD YOU THAT CISPLATIN IS THE MOST OTOTOXIC DRUG IN CLINICAL USE, RESULTING IN HAVE PRELIMINARY DATA INDICATING. [APPLAUSE] DISCLOSURES, I SERVE ON THE BOARD OF DIRECTORS OF THE STUTTERING FOUNDATION OF AMERICA, A NON-PROFIT ORGANIZATION, I AM SCIENTIFIC COLLABORATOR WITH A CONTRACT FUNDED BY NIH WITH ORGANIZATION KNOWN AS THE HOLLINS COMMUNICATIONS RESEARCH INSTITUTE, AND THERE'S NO DISCUSSION OF ANY DRUGS IN MY TALK. THE OBJECTIVES HERE, I HOPE TO DESCRIBE THE UNIQUE AND REALLY REMARKABLE NEUROLOGICAL DEFICITS IN THIS DISORDER, EVIDENCE FOR GENETIC ETIOLOGY AND DISCOVERY OF CAUSATIVE GENES AND GO TO EXPLAIN HOW ANIMAL MODELS CAN HELP REVEAL UNDERLYING NEUROPATHOLOGY IN STUTTERING. SO, STUTTERING IS COMMON NEURODEVELOPMENTAL DISORDERS, INCIDENCE OF 5% BEFORE SCHOOL AGE, RECOVER SPONTANEOUSLY OR HELP OF SPEECH THERAPY. BUT ABOUT 25% DO NOT. LEADING TO CONDITION KNOWN AS PERSISTENT STUTTERING AT ABOUT 1% OF THE POPULATION, AND THAT IS TRUE WORLDWIDE. IN ALL KNOWN LANGUAGE GROUPS, ALL CONTINENTS, ALL POPULATIONS. THE DISORDER IS CHARACTERIZED BY INTERRUPTION IN THE FLOW OF SPEECH THAT CAN OTHERWISE BE QUITE NORMAL. ONE OF THE REMARKABLE FEATURES IS THAT EVEN PEOPLE WHO STUTTER RELATIVELY SEVERELY CAN SPEAK PERFECTLY FLUENTLY UNDER SOME CIRCUMSTANCES. THERE ARE MANY THINGS NOT WRONG WITH THEIR SPEECH. THEY DON'T HAVE PROBLEMS WITH MEMORY OR WHAT WOULD BE CALLED WORD FINDING. THEY DON'T HAVE PROBLEMS WITH GRAMMAR. THEY DON'T HAVE PROBLEMS WITH SYNTAX. THEY DON'T HAVE AN ARTICULATION DISORDER LIKE A LISP. " THEY KNOW WHAT THEY WANT TO SAY BUT CAN'T AT THE RATE THEY WOULD LIKE. IT HAS PUZZLING CLINICAL FEATURES, IN ADDITION HAS A LOT OF DIFFERENT ASPECTS IN CLINICAL PRESENTATION, PEOPLE EXPERIENCE GAPS IN SPEECH, RESPEED THINGS, I I, I, I, I WENT TO THE STORE. PEOPLE WHO PRIMARILY GENERATE PROLONGATIONS. I-I-I WENT TO THE STORE. THESE DON'T SEEM TO BE NECESSARILY FIXED IN ANY ONE INDIVIDUAL. SYMPTOMS CAN WAX AND WANE. AND CHANGE FROM PREDOMINANTLY ONE TYPE TO ANOTHER. A JOKE I LEARNED FROM THE STUTTERING COMMUNITY IS THAT NO ONE STUTTERS WHEN THEY TALK TO THEIR DOG. TURNS OUT THIS IS LARGELY TRUE. YOU ASK YOURSELF WHAT KIND OF NEUROLOGIC DISORDER IS THIS? I WILL SAY THERE HAVE BEEN MANY HYPOTHESES ABOUT THE CAUSE OF THE DISORDER, OVER THE YEARS. OVER THE YEARS. THERE WE GO. THIS SORT OF RUNS THE GAMUT OF I'D SAY THE PAST CENTURY OF SUGGESTED CAUSES. BAD PARENTING WAS BIG. THERE STILL IS A SORT OF NEOBAD PARENTING HYPOTHESIS THAT ONE CAN HEAR THAT SOMEHOW CHILDREN, THEIR STUTTERING IS CREATED OR MADE WORSE BY SOMEHOW LISTENING -- WATCHING THE REACTION OF THEIR PARENTS. OVERLY STRICT TOILET TRAINING WAS VERY BIG FOR A LONG TIME. AND THERE IS A CORRELATION, STUTTERING TYPICALLY APPEARS AT AGE, OH, MAYBE 3 OR SOMETHING LIKE THAT. ABOUT THE TIME KIDS ARE GETTING TOILET TRAINED. SO ANXIETY IS ANOTHER MAJOR SUGGESTED CAUSE. THERE'S NO DOUBT THERE IS SOME CONNECTION BETWEEN ANXIETY AND THE SEVERITY OF STUTTERING. YOU CAN TAKE A RELATIVELY MILD STUTTERER AND TURN THEM INTO A SEVERE STUTTERER BY ASKING THEM TO GIVE AN OFF THE CUFF SPEECH TO 500 PEOPLE, SOMETHING LIKE THAT. HOWEVER, IT'S CLEAR THAT ANXIETY ITSELF IS NOT CAUSATIVE OF STUTTERING. POPULAR HYPOTHESIS, PEOPLE WITH STUTTERING HAVE PROBLEMS WITH AUDITORY FEEDBACK, DON'T PERCEIVE THEIR OWN SPEECH PROPERLY, AND THAT'S WHAT CAUSES THIS DISORDER. ANOTHER IS THAT WE KNOW THAT SPEECH FUNCTIONS ARE LEFT HEMISPHERIC LOCALIZED, HEAVILY LEFT HEMISPHERIC LOCALIZED BUT NOT EXCLUSIVELY, THERE HAS TO BE A CONNECTION BETWEEN THE CEREBRAL HEMISPHERE TO PRODUCE SPEECH, AND THAT MAYBE THERE'S SOMETHING WRONG THERE. ANOTHER POPULAR HYPOTHESIS WAS BASAL GANGLIA. THE DEFICITS IN THEIR SPEECH ARE OFTEN AT THE BEGINNING OF WORDS OR BEGINNING OF PHRASES OR SENTENCES. I, I, I, I WENT TO THE STORE. ONCE THEY GET STARTED, THEN THEY CAN PROCEED FLUENTLY. THIS SOUNDS LIKE TARDIVE DYSKENESIA, A DISORDER OF THE BASAL GANGLIA. MOTOR FUNCTION, SPEECH HAS HIGH REQUIREMENTS MOTOR FUNCTION DEMANDS, THE FASTEST MOTOR FUNCTION THAT HUMANS DO, MILLISECOND TIMING, SPEECH SOUNDS ARE ORDERED WITH MILLISECOND TIMING. SO MAYBE SOMETHING LIKE THE MOTOR CORTEX OR CEREBELLUM IS THE SITE OF THE PROBLEM IN THIS DISORDER. THERE HAVE BEEN MANY BRAIN IMAGING STUDIES OF STUTTERING.& I THINK 28 TO DATE OF A VARIETY OF TYPES, MRIs, fMRIs, PET STUDIES. ALMOST ALL SHOW LEFT TEMPORAL CORTICAL ALTERATIONS TIPALLY IN BROCA'S AREA OR POSTERIOR. THERE'S NO WAY TO TELL IF THEY ARE THE CAUSE OR RESULT OF STUTTERING. SPEECH IS KNOWN TO BE LOCALIZE THE LEFT HEMISPHERIC SINCE THE TIME OF -- SORRY. SINCE THE TIME OF PAUL BROCA WHO FAMOUSLY DESCRIBED A PATIENT WITH A FOCAL STROKE, AND WHO HAD NO OTHER NEUROLOGIC DEFICITS. AND AT THE TIME OF AUTOPSY HE FOUND THIS VERY SPECIFIC INFARCT IN WHAT IS NOW KNOWN AS BROCA'S AREA. IF ONE WANTED TO BE CYNICAL ABOUT THIS YOU COULD WONDER WHETHER IMAGING STUDIES HAVE GOTTEN US MUCH BEYOND THAT LEVEL OF UNDERSTANDING OF WHAT'S WRONG. ONE THING CLEAR IS GENETIC FACTORS ARE INVOLVED IN THE DISORDER. THE DISORDER IS KNOWN FROM A TOTAL OF NINE INDEPENDENT TWIN STUDIES, AND TWO ADOPTION STUDIES TO HAVE VERY HIGH HERITIBILITY, EXCEEDING .8, IN OTHER WORDS HERITABILITY AS A STATISTICAL CONSTRUCT BUT ONE CAN ROUGHLY THINK ABOUT IT AS MORE THAN 80% OF THE ATTRIBUTABLE PHENOTYPE IS DUE TO GENETIC RATHER THAN NON-GENETIC FACTORS, OKAY? HOWEVER, UNLIKE MANY DISORDERS, THIS DISORDER IS NOT TRANSLATED -- TRANSMITTED IN A MENDELIAN FASHION IN FAMILIES, CLUSTERS IN FAMILIES BUT NO CLEAR CONSISTENT PROOF IT IS TRANSMITTED IN A DOMINANT FASHION OR RECESSIVE FASHION OR ANY OTHER FASHION. AND GENETIC LINKAGE STUDIES USED TO IDENTIFY LOCATION OF CAUSATIVE GENES IN FAMILIES THAT CARRY SUCH GENES, OURS INCLUDED, WERE A DISASTER, FAILED TO REPLICATE EACH OTHER, DIDN'T PRODUCE HIGHLY STATISTICALLY SIGNIFCANT RESULTS, SO WE MOVED TO UNUSUAL FAMILIES IN EXOTIC PLACES AND ADVANTAGEOUS POPULATION ALSO TO IDENTIFY GENETIC LINKAGES THAT REVEAL NOW EXISTENCE OF CAUSATIVE ALLELES OF LARGE EFFECT AT MANY LOCI. SO THERE'S CLEAR STRONG EVIDENCE FOR GENETIC LINKAGE TO STUTTERING, AT LOCI ON ALL THESE CHROMOSOMES. SO THERE ARE A FAIR NUMBER OF GENES THAT WHEN MUTATED CAUSE THIS SAME DISORDER. OKAY? AND WE'VE USED THESE LINKAGE STUDIES TO IDENTIFY FIRST GENES IN A CAUSE STUTTERING WHICH I CAN TELL YOU ABOUT HERE. SO THE FIRST THREE ARE GENES THAT HAVE EXTREMELY LONG NAMES. WE ABBREVIATE THEM. THE FOURTH IS AP 4E1, ANOTHER LONG NAME. WHAT THEY HAVE IN COMMON IS THEY ALL ENCODE COMPONENTS OF THE INTRACELLULAR TRAFFICKING MECHANISM, WHICH IS UNIVERSAL ACROSS EUKARYOTIC CELLS, OKAY? THIS INCLUDES THINGS LIKE ENDOCYTOSIS, ENDOSOMES, THE TRANSGOLGI NETWORK, ULTIMATELY THE LYSOSOME, SOMETIMES KNOWN AS THE CELL'S RECYCLING BIN. SO THESE GENES -- SO WHAT DOES A DEFICIT IN INTRACELLULAR TRAFFICKING WHICH EXISTS IN ALL CELLS IN THE BODY WITH EXCEPTION OF RED BLOOD CELLS HAVE TO DO WITH STUTTERING? HOW DOES IT PRODUCE SUCH A SPECIFIC MOTOR DEFICIT? BECAUSE WE BROUGHT PATIENTS WITH MUTATIONS IN THESE GENES HERE TO THE NIH CLINICAL CENTER AND GAVE THEM EXTREMELY DETAILED MEDICAL AND PARTICULARLY NEUROLOGICAL WORKUPS, THERE'S NOTHING ELSE WRONG WITH THESE PATIENTS OTHER THAN THEIR SPEECH DISORDER, OKAY? SO, THE SHORT ANSWER IS WE DON'T KNOW HOW A MODEST DEFICIT IN INTRACELLULAR TRAFFICKING SPECIFICALLY CAUSES A PROBLEM OF SPEECH FLUENCY SO IN ORDER TO DIG DEEPER INTO THIS WHAT WE REALLY NEED IS AN ANIMAL MODEL. AND THE PROBLEM HERE OF COURSE IS THAT ANIMALS DON'T TALK. BUT MICE HAVE SOME INTERESTING FEATURES. THEY HAVE EXTREMELY RICH VOCAL COMMUNICATION, MUCH OR MOST IS ULTRASONIC, NOT IN FACT EVEN FULLY CHARACTERIZED, CLEARLY CONTEXT SPECIFIC. ONE PARTICULAR CLASS OF MOUSE ULTRASONIC VOCALIZATION ARE EVOKED IN THE LABORATORY, PUP ISOLATION CALLS, DIFFERENT INBRED STRAINS HAVE DIFFERENT UP ISOLATION CELLS. THE YOUNG MICE HAVE THE EXPRESSLY VOCALIZATION OF BIOLOGICAL PARENTS, NOT ADOPTIVE PARENTS. IT'S A SIMPLE ASSAY. YOU TAKE THE MOUSE OUT OF THE NEST AND LEAVE IT. AFTER, OH, ABOUT A MINUTE, THESE MICE START EMITTING THESE, IT PROVOKES A STRONG RESPONSE FROM THE MOTHER, COMES AND FINDS AND RETRIEVES THEM AND BRINGS THEM BACK TO THE NEST. NOW OF COURSE MOUSE VOCALIZATION IS NOT A MODEL FOR HUMAN SPEECH. THE QUESTION IS, COULD MICE BE A MODEL FOR THE VOLITIONAL CONTROL OF VOCALIZATION? OKAY. SO THE DESIRE TO SPEAK. SO, IT TURNS OUT THAT COMPLETE LOSS OF FUNCTION MUTATIONS IN ALL THESE FOUR GENES ARE KNOWN TO MEDICAL GENETICISTS, ASSOCIATED WITH SEVERE FATAL MENDELIAN RECESSIVE DISORDERS, METABOLIC DISORDERS, USUALLY FATAL IN CHILDHOOD. SO, IF YOU JUST KNOCK OUT THESE GENES IN THE MOUSE, YOU GET THE MURINE EQUIVALENT OF THOSE FATAL HUMAN DISORDERS, THE MOUSE DIES AT A VERY YOUNG AGE, YOU CAN'T DO MUCH WITH IT. YOU HAVE TO ENGINEER THE HUMAN STUTTERING MUTATIONS INTO THE MOUSE, WHICH WAS DONE BY THIS TALENTED POSTDOCTORAL FELLOW IN MY LAB. THE ANIMALS ARE BORN IN NORMAL NUMBERS, WITH DISTRIBUTION OF SEX AND GENOTYPE, ANIMALS GROW AND REPRODUCE NORMALLY, EXHIBIT NORMAL BEHAVIOR ON A WIDE VARIETY OF BEHAVIORAL ASSAYS, AND MUCH ABOUT THEIR ULTRASONIC VOCALIZATIONS IS NORMAL. HOWEVER, NOT EVERYTHING. SO, THEY DISPLAY LESS VOCALIZATION. AND THE OVERALL DURATION OF THEIR SORT OF BOUTS OF VOCALIZATION IS THE SAME. THE REASON THEY VOCALIZE LESS IS BECAUSE THERE ARE MORE GAPS AND PAUSES IN THEIR STREAM OF VOCALIZATION, OKAY? AND THIS IS TRUE WITH A NUMBER OF DIFFERENT HUMAN STUTTERING MUTATIONS, TRUE ACROSS DIFFERENT STRAINS OF MICE, IT'S TRUE SORT OF NO MATTER HOW YOU DO THE EXPERIMENT. IT'S VERY REPRODUCIBLE FINDING BUT MORE IMPORTANTLY IF YOU TAKE THE SPEECH OF THE HUMANS WHO CARRY THESE SAME MUTATIONS, AND YOU TAKE THE ACOUSTIC STRUCTURE, GIVE IT TO THE COMPUTER PROGRAM, IT FINDS THE EXACT SAME PHENOTYPE. INCREASED PAUSES AND GAPS IN OTHERWISE FLUENT FLOW OF SPEECH. WE CAN'T CALL THESE STUTTERING MICE BUT MAYBE, QUOTE, STUTTERING MICE. OKAY. SO NOW WE'RE ABLE TO CAREFULLY LOOK AT THESE ANIMALS IN SEARCH FOR SPECIFIC ABNORMALITIES, TRADITIONAL TYPICAL ANIMAL-WIDE H&E PATHOLOGY STAINING, REVEALED NOTHING. WE COULDN'T FIND ANYTHING. BUT DR. HAN, WHOSE PHOTOGRAPH I SHOWED YOU, SAID WE'RE NOT GOING TO STOP. THERE HE DID MORE DETAILED STUDIES WITH BRAIN CELL TYPE SPECIFIC ANTIBODIES, HE THEN USED WITH IMMUNOHISTOCHEMISTRY TO LOOK AT CELL CLASSES IN THE BRAIN AND WENT THROUGH MANY ANTIBODIES, œTYPES IN THE BRAIN AND FOUND NOTHING, UNTIL HE TRIED -- UNTIL HE TRIED AN ANTIBODY KNOWN AS ANTI-GFAP, WHICH IS THE CLASSIC MARKER OF ESTROCYTES, THOUGHT OF SUPPORTING ACTORS IN THE BRAIN, EVIDENCE ACCUMULATING SIGNIFICANTLY ASTROCYTES PLAY MORE ACTIVE ROLE IN THE BRAIN THAN PREVIOUSLY THOUGHT TO PLAY. THEY ARE PARTICULARLY RICH IN WHITE MATTER TRACKS IN THE BRAIN, WHICH DO NOT CONTAIN NEURONAL CELL BODIES, PRIMARILY COMPOSED OF LONG AXONAL PROCESSES. AND HERE'S SORT OF WHAT THIS DATA LOOKS LIKE. THIS IS A CORONAL SECTION OF THE MOUSE BRAIN, THE CORPUS CALLOSUM IN WHITE, AND ANTI-GFAP IN GREEN. WILDTYPE HAS PLENTY. BLUE STAINS NUCLEI, WHERE THE CELLS ARE, REDUCED IN 8 DAY OLD PUPS, MORE REDUCED IN OLDER MICE, SO THERE'S CLEARLY SOMETHING NOT RIGHT WITH THE ASTROCYTES IN THE BRAINS OF THESE ANIMALS. SO, HAN TOOK A COMPLETELY ORTHOGONAL APPROACH, WHICH WAS TO INTRODUCE THESE MUTATIONS, MUTATIONS IN THESE GENES, JUST IN SPECIFIC CELL TYPES OR CELL LINEAGES WITHIN THE MOUSE BRAIN. AND THAT CAN BE DONE, THANKS TO THE AVAILABILITY OF ALL OF THESE NEURONAL CRE DRIVER LINES, MAINTAINED AT ROCKEFELLER UNIVERSITY. HERE'S AN EXAMPLE. THIS IS THE EXPRESSION JUST OF ACTUALLY GFP, ANTIBODY STAINED, EXAMPLE OF HOW SPECIFIC CRE DRIVER LINES CAN CONTROL GENE EXPRESSION. HERE IS, FOR INSTANCE, A GFP UNDER THE CONTROL OF A ADORA2, CLASSIC BASAL GANGLIA. HERE IS PCP 2, THIS IS THE CEREBELLUM, MOTOR CONTROL. HERE IS GFAP, PLP, ANOTHER ASTROCYTE TYPE. THESE ARE LARGE EXPERIMENTS THAT REQUIRE A GREAT DEAL OF BREEDING BUT HE SHOWED EXPRESSION OF THE MUTATION JUST IN GFAP CELLS REPRODUCES THE VOCALIZATION DEFICITS SEEN IN THE WHOLE ANIMAL KNOCK-IN MOUSE, BUT IN NO OTHER CELL TYPES YET TESTED. SO NOT ONLY DOES PUTTING HUMAN STUTTERING MUTATIONS INTO THE MOUSE RESULT IN ASTROCYTE DEFICITS, WHEN YOU EXPRESS MUTATIONS IN THESE GENES JUST IN ASTROCYTES THOSE MICE ACQUIRE THE SAME VOCALIZATION DEFICIT. OKAY. SO, IN ADDITION, WE WANTED TO TAKE A LOOK AT JUST THE PHYSICAL STRUCTURE OF THE BRAIN, SORT OF DO OUR OWN VERSION OF IMAGING. AND WE WERE ABLE TO DO THIS IN P8 MICE IN THE NIH MOUSE IMAGING FACILITY, WHICH IS AT THE FAR END OF THIS BUILDING, WHICH I CAN'T RECOMMEND HIGHLY ENOUGH TO ANYONE WHO MIGHT HAVE AN INTEREST IN SUCH A THING. THEY HAVE 14 TESLA SCANNER, AND A GREAT DEAL OF PROFESSIONAL EXPERTISE IN HOW TO USE IT. WE SO FAR SCANNED THREE MUTANT ANIMALS AND THREE WILD TYPE LITTERMATES, SCORED MORPHOLOGY BLINDING. MUTANT MICE DISPLAY SUBTLE DIFFERENCE IN CORPUS CALLOSUM AND ANTERIOR. THIS IS THE CORONAL FRONT-ON VIEW, THIS IS AN OLD MEDICAL TEXT BOOK DRAWING OF THE CORPUS CALLOSUM. THEY CONNECT THE TWO HEMISPHERE OF THE BRAIN, OKAY? WE FOUND FOUR STUTTERING GENES TO DATE, HAVE TO DO WITH INTRACELLULAR TRAFFICKING. IN MICE THEY DEVELOP A VOCALIZATION DEFICIT THAT RESEMBLES SALIENT FUTURES OF HUMAN DISORDER. WE HAVE MORE GENES TO FIND, DON'T KNOW WHAT THEY WILL CODE FOR. THEY MAY BE SOMETHING IN INTRACELLULAR TRAFFICKING OR MAYBE NOT. BUT WE HAVE RECENT RESULTS, I LIKE TO TALK ABOUT A LITTLE BIT OF UNPUBLISHED RESULTS WHICH I'LL TALK ABOUT NOW. WE HAVE THIS FAMILY WHICH WE ENROLLED IN PAKISTAN, A CONSANGUINEOUS FAMILY, STUTTERING IN THE BOYS IN GENERATIONS. CAUSATIVE GENE ON LONG ARM OF CHROMOSOME 3, WE FOUND ONE CHANGE, SEEMED LIKE A SUBTLE CHANGE, IN PLACE OF NORMAL VALE NEXT, AMINO ACID 719 IN ZBTB THERE - 20, WE INCIDENT FIND MUTATIONS IN ZBTB20, OUTSIDE THIS FAMILY, OKAY? THERE WE GO. BUT WE STARTED LOOKING MORE CLOSELY AND FOUND OUT IN FACT THE NORMAL VALENE AT THIS POSITION IS COULD BE SERVED IN ALL SPECIES THAT ARE KNOWN, GENOMES OF OVER 100 SPECIES HAVE BEEN SEQUENCED, VALENE IN ALL EXCEPT ONE, SEALOCANTH, A LIVING FLOW OF SPEECHEL, A FISH THIS IS IS EXTREMELY RARE IN ALL HUMAN GENETIC DATABASES, THERE ARE ABOUT 40 OF THEM IN 120 THIS TO EXOMES, 120,000 PEOPLE, ALL 40 OF THESE PEOPLE IN THE DATABASES ARE FROM SOUTH ASIA, ALL HETEROZYGOTES. THE ONLY PEOPLE IN THE WORLD œISOLUCINE VARIATION ARE THES PEOPLE IN THIS FAMILY, PKSD77 AND THEY ALL STUTTER. ENCODES ZINC FINGER TRANSCRIPTION FACTOR, POSITION 719 RESIDES IN ONE OF THE DNA BINDING DOMAINS SO TRANSCRIPTION FACTORS OF COURSE CONTROL A DEVELOPMENTAL PROGRAM WITHIN CELLS, SO WHAT DOES ZBPB20 CONTROL? YOU CAN IMAGINE OUR INTEREST WHEN WE SAW THIS PAPER, PROMOTES ASTROCYTE GENESIS DURING NEOCORTICAL DEVELOPMENT. SO THIS, WE KNOW SOMETHING INTERESTING WHEN WE SEE IT, SO WE HAVE TAKEN TO PURSUING THIS. AT THE SAME TIME, ACTUALLY A FORMER ALUM OF THE NIDCD HAS BEEN DOING MORE DETAILED NEURO IMAGING STUDY IN YOUNG CHILDREN, TYPICALLY THEY HAVE NOT BEEN SUBJECTS FOR BRAIN IMAGE STUDIES OF STUTTERING BECAUSE IT'S HARD TO GET THEM TO HOLD STILL IN THE SCANNER, BUT WHAT THEY ARE NOW FINDING IS IN FACT SUGGESTIONS OF DEFICITS IN THE CORPUS CALLOSUM IN THESE KIDS. SO THIS IS ALL SOUNDING VERY SUGGESTIVE TO US, WHERE IS THE NEUROPATHOLOGY OF STUTTERING NOW? THERE ARE PERHAPS MANY MORE GENES TO BE FOUND FOR THIS DISORDER, ALL THE GENES IDENTIFIED TO DATE POINT TO A DISORDER OF INTRACELLULAR TRAFFICKING. TURNS OUT A LOT OF NEUROLOGIC DISEASES ULTIMATELY HAVE TRAFFICKING DEFICITS AS THEIR THE FIRST ONES TO BE FOUND WERE RARE MENDELIAN DISORDERS BUT NOW THESE DEFICITS ARE BEGINNING TO BE FOUND IN MUCH MORE COMMON NEUROLOGIC DISORDERS, FOR INSTANCE THERE'S A LOT OF DISCUSSION THAT ALZHEIMER'S DISEASE IS AT ITS FOUNDATION A TRAFFICKING DISORDER. THE NEUROFIBROLARRY PLAQUES AND TANGLES ARE END STAGE DISEASE, APPEAR AT AUTOPSY. AT EARLY STAGES IN THE RARE INSTANCES WHERE PEOPLE HAVE BEEN ABLE TO GET A BRAIN BIOPSY, THEY DON'T SEE THOSE. WHAT THEY SEE ARE SWOLLEN ENDOSOMES, THEY SEE -- OF COURSE THE REASON THEY ARE SWOLLEN IS BECAUSE THINGS ARE TRAFFICKED IN BUT DON'T GET TRAFFICKED. DISORDERS OF TRAFFICKING MAY BE MORE COMMON IN NEUROLOGIC DISEASES, DISEASE IN GENERAL, THAN WAS PREVIOUSLY APPRECIATED. OUR NEXT CONCLUSION IS THAT ASTROCYTES APPEAR TO BE A PRIMARY CELL TYPE IN WHICH THIS PATHOLOGY IS EXPRESSED. PARTICULARLY IMPORTANT IN WHITE MATTER TRACKS, TRACKS THAT CONNECT HEMISPHERE OF THE BRAIN, MAY REPRESENT THE MAJOR PATHOLOGY, SITE OF THE MAIN PATHOLOGY IN STUTTERING. OF COURSE, I'LL GO BACK TO -- OOPS. SO HERE ARE THE ORIGINAL -- MY ORIGINAL LIST OF POSSIBLE CAUSES SUGGESTED OVER THE MANY DECADES. AND I'LL JUST TELL YOU, I WAS NEVER A FAN OF THIS ONE. I WAS PUTTING MY MONEY ON THIS ONE, FOR A BUNCH OF REASONS. BUT IT LOOKS LIKE I WOULD SAY AT THE MOMENT WE CERTAINLY DON'T HAVE ALL OF THE DISORDER EXPLAINED BY THE GENETIC FINDINGS WE'VE HAD TO DATE. BUT I WOULD SAY THAT THE EVIDENCE WE FOUND SO FAR IS MORE SUPPORTIVE OF THIS HYPOTHESIS, FAR MORE SUPPORTIVE THAN ANY OF THE OTHERS. OKAY. SO, IN THE FUTURE WE ARE WORKING AND TESTING THE HYPOTHESIS THIS MUTATION DISTURBS ASTROCYTE DEVELOPMENT, WE WANT TO TEST THE HYPOTHESIS THAT THIS PARTICULAR MUTATION IN THIS GENE RESULTS IN VOCALIZATION DEFICITS IN MICE, WE'RE PUTTING THAT GENE INTO MISS. THEN WHAT ABOUT ALL THESE OTHER GENES? I TOLD YOU WE FOUND FOUR. THERE ARE AT LEAST ANOTHER SIX REMAINING TO BE FOUND. WE DON'T KNOW WHAT THOSE ARE. BUT THE POWER OF GENETICS IS IT CAN FIND THEM. AND TELL US MORE ABOUT THE UNDERLYING PATHOLOGY OF THE DISORDER. FINALLY I'D LIKE TO SAY THAT THE LONG-TERM GOAL OF OUR RESEARCH HAS BEEN IN WHAT I SOMETIMES CALL THE MEDICALIZATION OF THIS DISORDER. PEOPLE WHO STUTTER ARE NOT SEEN BY PHYSICIANS. THEY ARE SEEN BY SPEECH LANGUAGE PATHOLOGISTS WHO ARE VERY HELPFUL BUT WORK EMPIRICALLY. TREATMENTS ARE BASED ON TRIAL AND ERROR, AND ARE USED JUST BECAUSE EMPIRICALLY THEY TEND TO IMPROVE FLUENCY. THEY HAVE NOT BEEN BASED ON A FUNDAMENTAL UNDERSTANDING OF THE UNDERLYING CAUSES OF THE DISORDER. I THINK IT'S CLEAR THAT STUTTERING IS MOVING INTO THE WORLD OF NEUROLOGY, AND WE PERSONALLY THINK, I PERSONALLY THINK, THAT GREATER MEDICAL ATTENTION TO THIS DISORDER IS ULTIMATELY WARRANTED. OKAY. AND THEN FINALLY, THIS IS 20 YEARS OF WORK BASED ON THE EXCEPTIONAL EFFORTS OF A VERY LARGE NUMBER OF PEOPLE AND ORGANIZATIONS, I DON'T HAVE TIME TO MENTION THEM ALL BUT WILL TAKE THE TIME TO SAY THAT NONE OF THIS WOULD HAVE BEEN POSSIBLE WITHOUT THE THOUSANDS OF STUTTERING SUBJECT WHO IS PARTICIPATED IN GENETIC STUDIES, AND TO THEM PARTICULARLY WE GIVE OUR THANKS. WITH THAT I'LL STOP AND THANK YOU ALL FOR YOUR ATTENTION. [APPLAUSE] >> ALL RIGHT. SO, OPPORTUNITIES NOW TO ASK QUESTIONS AND HOPEFULLY GET SOME ANSWERS. LET'S START. >> WELL, DR. CUNNINGHAM, SO I WAS LOOKING AT THE CANDIDATES OF INTERACTION BETWEEN SODIUM THIOSULFATE, CISPLATIN COMPLEX, WITH THE AMINO ACID GROUP REALLY, SO BASICALLY DISTRIBUTION OF CHELATING PARTNERS, THE POSSIBILITY OF THE GROUP WITH THE THIOSULFATE GROUP, STUDIES EASILY IN A CHEMICAL REACTION. DID ANYBODY TRY TO SEE WHAT IS THIS POSSIBILITY OF TRANSLATION REACTION? >> WELL, AM I ON? CLEARLY YOU'RE A MUCH BETTER CHEMIST THAN I AM. YEAH, I THINK YOU'RE RIGHT. THE CHEMICAL REACTION BETWEEN CISPLATIN AND SODIUM THIOSULFATE IS UNDERSTOOD, AND THAT BINDING OF THE CISPLATIN DIRECTLY OF IS THIOSULFATE IS THE REASON THE THERAPY WORKS AND ALSO THE REASON YOU HAVE TO SEPARATE IN TIME ADMINISTRATION OF THE CISPLATIN FROM ADMINISTRATION OF THE SODIUM THIOSULFATE. IF YOU ADMINISTER AT THE SAME TIME OF COURSE YOU'LL REDUCE OR ELIMINATE THE THERAPEUTIC EFFICACY OF THE CISPLATIN ITSELF BECAUSE OF THE KIND OF BINDING YOU'RE TALKING ABOUT. >> IS IT PROVEN IF YOU DON'T WAIT TILL 6 HOURS YOU MIGHT INACTIVATE THE CISPLATIN? >> IN ANIMALS, YES. >> SO THAT'S A GOOD VALIDATED THAT THIS IS HAPPENING IN REAL LIFE. >> YES. >> OKAY. >> IT WASN'T OUR STUDY. >> THANK YOU. ANY OTHER BETTER DRUGS COMING OUT OR -- >> I'M SORRY? >> ANY OTHER BETTER DRUGS THAT MIGHT BE -- >> OH, BETTER DRUGS. I'D LOVE TO KEEP YOU POSTED ON OUR SCREEN IN COLLABORATION WITH NCATS. THANKS. >> FOR DR. DRAYNA, DID YOU MEASURE THICKNESS OF CORPUS CALLOSUM, INCREASING OR DECREASING IN STUTTERING PATIENTS? >> THAT'S A TERRIFIC QUESTION. THERE HAVE BEEN NO LONGITUDINAL STUDIES. THESE ARE ALL SINGLE TIME POINT STUDIES AND THEY HAVE ALL BEEN SORT OF POPULATION-BASED, UNRELATED TO INDIVIDUALS, CASES VERSUS CONTROLS.& THAT'S THE KIND OF DATA THERE IS FOR ALL THOSE STUDIES. >> ALL RIGHT. GOOD LUCK. THANK YOU. >> THANK YOU. >> CAN YOU SPECULATE ON HOW STATINS MIGHT BE EFFECTIVE IN REDUCING THE TOXICITY OF CISPLATIN? >> IF I CAN START WITH ADMITTING THAT IT'S PURE SPECULATION. SO, IN OUR LAB WE HAVE FOR 15 YEARS NOW STUDIED PROTECTION OF THE INNER EAR BY A CLASS OF PROTECTIVE MOLECULES CALLED HEAT SHOCK PROTEINS, WELL KNOWN UBIQUITOUS RESPONSES. IF WE USE OTHER DRUGS THAT INDUCE HEME OXYGENASE 1, HSP 32, WE CAN GET PROTECTION AGAINST CISPLATIN INDUCED HAIR CELL DEATH, SENSORY HAIR CELL DEATH IN THE INNER HERE. SO WHEN WE HAD SHOWN THAT TWO DIFFERENT INDUCERS OF THE HEAT SHOCK PROTEIN REDUCED CISPLATIN INDUCED PLAT UM WE LOOKED FOR FDA DRUGS THAT MIGHT BE INDUCERS SO WE DON'T KNOW IF THE PROTECTIVE EFFECTS WE SEE IS RELATED TO CHOLESTEROL MANAGEMENT AND WE'RE ACTUALLY TRYING TO WORK ON STUDIES TO DETERMINE THAT. WE DO KNOW THAT WHEN WE GIVE SYSTEMIC STATINS TO MICE, WE DO SEE INDUCTION OF HO 1 IN THE COCHLEA, IT'S POSSIBLE IT'S SOME PLEIOTROPIC EFFECT OF STATINS UNRELATED TO THE MANAGEMENT OF CHOLESTEROL, BUT TRUTH IS WE DON'T HAVE ANY DATA ON IT. >> OKAY. YES, SIR. >> THE LAST THING THAT YOU MENTIONED IN YOUR TALK WAS A SHIFT AWAY, A SHIFT OF TREATING STUTTERING AS A MEDICAL DISORDER. AND ONE OF THE THINGS YOU SAID IS THAT SPEECH LANGUAG PATHOLOGISTS KIND OF TREAT BASED ON TRIAL AND ERROR, AND PROVIDE STRATEGIES, BUT THEY ARE NOT REALLY ADDRESSING STUTTERING AS A MEDICAL DISORDER. DO YOU SEE A FUTURE WHERE STUTTERING IS TREATED AS A MEDICAL DISORDER? BECAUSE FOR MY UNDERSTANDING OF LANGUAGE AND ARTICULATION, THAT KIND OF IS THE BEST STRATEGY OUT THERE. WHAT DO YOU THINK IS THE GOAL OF THE TREATING STUTTERING AS A MEDICAL DISORDER IF THERE'S ANYTHING MORE THAN JUST GETTING A BETTER BASIC SCIENCE UNDERSTANDING? >> RIGHT. RIGHT. SO THIS IS A VERY IMPORTANT POINT. FIRST THERE ARE PEOPLE WHO ARE ALREADY WORKING ON IT. THERE'S DR. GERALD MAGUIRE AT U C RIVERSIDE, A PSYCHIATRIST, AND HE'S VERY INTERESTED IN TRYING BASIC PSYCHIATRIC KINDS OF APPROACHES. AND THE GOAL THERE I THINK A LOT OF IT IS IS TO TRY AND INTERSECT THE PROBLEM AT THE ANXIETY, THE ANXIETY PHASE, SORT OF. SO HE'S BEEN WORKING ON THIS FOR A LONG TIME. AND THE PROBLEM HAS BEEN MANY, MANY DRUGS WILL IMPROVE FLUENCY AT THE BEGINNING BUT THEN THAT EFFECT TENDS TO SORT OF GO AWAY OVER TIME. BUT I'LL POINT OUT THAT A PAPER CAME OUT A COUPLE MONTHS AGO, THERE WAS A DRUG SCREEN THAT WAS AIMED AT ALZHEIMER'S DISEASE THAT STARTED LOOKING AT THINGS THAT WOULD CORRECT THE INTRACELLULAR TRAFFICKING DEFICIT SEEN IN ALZHEIMER'S NEURONS IN VITRO, AND THEY GOT A CANDIDATE. THEY HAVE A DRUG HIT. AND OF COURSE THAT'S A LONG WAY AWAY FROM A DEVELOPMENT PROJECT, AND THAT'S A LONG WAY FROM A CLINICAL TRIAL, THAT'S A LONG WAY FROM A DRUG AVAILABLE TO TREATING PHYSICIANS. BUTFUL-- I CAME TO THE NIH FROM THE PHARMACEUTICAL INDUSTRY. AND ONE THING I KNOW IS THAT THE PHARMACEUTICAL INDUSTRY IS EXTREMELY GOOD AT DEVELOPING A DRUG IF THEY HAVE THE RIGHT TARGET. AND SO THE PROBLEM IS HISTORICALLY MAKING SURE YOU'VE GOT THE RIGHT TARGET. SO, THE ADVANTAGE OF GENETIC APPROACHES IS IT GETS US TO MOLECULES. AND THAT'S THE LEVEL AT WHICH DRUGS WORK. THEY WORK AT THE MOLECULAR LEVEL. SO, WE ARE HOPEFUL AT MOLECULAR CAUSES ARE ELUCIDATED TARGETS WILL PRESENT THEM SEVENTY. >> COOL. THANK YOU. >> SURE. >> OKAY. SO I WANTED TO ASK ONE FINAL QUESTION. I KNOW WE'RE A LITTLE BIT BEYOND TIME. BUT DENNIS, CAN YOU SPECULATE, MAYBE, LIKES LIKE THE EVIDENCE SHOWS THE ASTROCYTE IS THE TARGET HERE. BUT IS IT THE CAUSE? OR IS IT THE INTERACTION BETWEEN THE ASTROCYTE AND THE NEURON? AND DO YOU HAVE ANY INSIGHTS INTO THAT? > RIGHT. SO WHAT'S GOING ON IN THE ASTROCYTES HERE? I MEAN, THERE MAY BE A NOT QUITE I THINK WHAT ATHAT'S- NEUROPATHOLOGIST WOULD WANT TO KNOW. THE ANSWER IS WE DON'T KNOW YET. I THINK THE ADVANTAGE IS THE ADVANTAGE OF AN ANIMAL MODEL IS THAT THERE'S A LOT WE WILL BE ABLE TO DO. I SHOULD POINT OUT THAT THERE'S A LOT -- ASTROCYTES ARE BEGINNING TO COME INTO THEIR OWN NOW I THINK, GETTING TO BE MORE UNDERSTOOD, AND WE'RE HOPE THAT CAN AS MORE ATTENTION GETS PAID TO ASTROCYTES WE'LL BE ABLE TO RIDE THAT WAVE AND LEARN MORE ABOUT WHAT MIGHT ACTUALLY BE GOING ON IN OUR PARTICULAR DISORDER. >> ALL RIGHT. WE WANT TO THANK BOTH PRESENTERS FOR AN EXTREMELY WELL-DESERVED SESSION FOR TODAY. AND WE HOPE TO SEE YOU BACK AGAIN NEXT WEEK. THANKS VERY MUCH. [APPLAUSE]