Title Epigenetske promjene u mišjim modelima Ruijs-Aalfsovog sindroma i raka mokraćnog mjehura
Title (english) Epigenetics alterations in mouse models of Ruijs-Aalfs syndrome and bladder cancer
Author Maria Bošković
Mentor Janoš Terzić (mentor)
Committee member Tatijana Zemunik (predsjednik povjerenstva)
Committee member Ivana Novak (član povjerenstva)
Committee member Ana Marušić (član povjerenstva)
Granter University of Split School of Medicine Split
Defense date and country 2022, Croatia
Scientific / art field, discipline and subdiscipline BIOMEDICINE AND HEALTHCARE Basic Medical Sciences Human Genetics, Genomics and Proteomics
Universal decimal classification (UDC ) 61 - Medical sciences
Abstract Epigenetske, genomske i proteomske promjene obilježja su razvoja raka, kao i sindroma starenja. S naglaskom na te procese proučavani su mišji modeli Ruijs-Aalfsovog sindroma i raka mokraćnog mjehura.
Naša istraživačka skupina otkrila je mutacije u genu SPRTN kao uzrok progeroidnog poremećaja poznatog kao Ruijs-Aalfsov sindrom (RAS), rijetke bolesti karakterizirane preranim starenjem i razvojem hepatocelularnog karcinoma u adolescentskoj dobi. Da bismo proučavali RAS, generirali smo Sprtn knock-in miševe (Sprtnki/ki) s mutacijom pronađenom u pacijenata. Ti miševi rekapituliraju RAS-fenotip te imaju smanjeno kondenzirani kromatin, jezgrene atipije i kraće telomere. Stoga smo profilirali epigenom miševa Sprtnki/ki analizirajući njihov metilom, kao i dostupnost kromatina, korištenjem metoda sekvenciranja i različitih molekularnih pristupa. Pronašli smo globalnu hipometilaciju i različitu dostupnost kromatina, s prekomjernom regulacijom mRNA koja utječe na promjene u metabolizmu lipida. Molekularno testiranje identificiralo je interakciju proteina SPRTN s ključnim epigenetičkim proteinima - DNMT1 i UHRF1, otkrivajući mehanističku poveznicu s uočenim promjenama metiloma. Ovi podaci podupiru ideju da deregulacija epigenoma može biti temeljni mehanizam teškog fenotipa uočenog u bolesnika s RAS-om, kao i u miševa s mutacijom. Budući da je epigenetika, posebice metilacija DNA, nedavno prepoznata kao jedna od osnova starenja i karcinogeneze, stečeni uvid u ulogu proteina SPRTN u epigenetici od iznimne je važnosti.
Dodatno smo proučavali potpise metilacije DNA i njihov utjecaj na ekspresiju gena u mišjem modelu raka mokraćnog mjehura (RMM) nakon primjene N-butil-N-(4-hidroksibutil)-nitrozamina. Budući da je deregulirana metilacija DNA praćena promjenama u izražaju gena važan element patogeneze raka, profilirali smo metilom i transkriptom RMM-a koristeći metode sekvenciranja. Hipo- i hipermetilacija su izmjerene u neinvazivnom RMM, u CpG-ovima gena uključenih u mišićne i živčane procese, ali se nisu odrazili na ekspresiju odgovarajućih gena. Međutim, invazivni tumori su pokazali promjene hipermetilacije u istim procesima s refleksijom na ekspresiju gena. Naši nalazi upućuju na to da bi se progresija i potencijal RMM-a mogli otkriti profiliranjem metilacije u predinvazivnoj fazi, što bi moglo pomoći u boljem praćenju bolesnika s ovom bolešću.
Abstract (english) Epigenetic, genomic, and proteomic changes are hallmarks of cancer development as well as of the aging syndromes. With an emphasis on those processes’ mice models of Ruijs-Aalfs syndrome and bladder cancer were studied.
Our research group has identified mutations in the SPRTN gene as a cause of progeroid disorder known as Ruijs-Aalfs syndrome (RAS), a rare disease characterized by premature aging and the development of early-onset hepatocellular carcinoma. To study RAS more deeply we generated Sprtn knock-in mice (Sprtnki/ki) harboring the mutation found in RAS patients. These mice display phenotypes reminiscent of RAS but also abnormal nuclei, less condensed chromatin, and shorter telomeres. Thus, we profiled the epigenome of Sprtnki/ki mice by analyzing their methylome as well as chromatin landscape using sequencing and different molecular approaches. Global hypomethylation was observed and different chromatin accessibility, with global upregulation of mRNA affecting changes in lipid metabolism. Molecular testing identified the interaction of SPRTN with key epigenetics players - DNMT1 and UHRF1 revealing mechanistic insight into observed methylome changes. These data support the notion that the epigenome deregulation may be an underlying mechanism of the severe phenotype observed in RAS patients as well as in mutant mice. Because epigenetics, in particular DNA methylation, has recently been recognized as one of the pillars of aging and carcinogenesis, gaining insight into Spartan's role in epigenetics is of primary importance.
We additionally studied DNA methylation signatures and its impacts on gene expression in mouse models of urinary bladder cancer (BC) following N-butyl-N-(4-hydroxybutyl)-nitrosamine administration. Because aberrant DNA methylation accompanied by changes in gene expression is an important element of cancer pathogenesis, we profiled the methylome and transcriptome of BC using sequencing approaches. Hypo- and hypermethylation were present in non-invasive BC, across CpGs of the genes involved in muscle- and neuronal-related pathways, but were not reflected in the expression of the respective genes. However, invasive tumors displayed only hypermethylation changes with alterations in gene expression in these genes. Our findings suggest that BC progression could be revealed through methylation profiling at its pre-invasive stage, which could assist in better monitoring of BC patients.
Keywords
metilacija DNA
progerija
rak jetre
rak mokraćnog mjehura
kromatin
izražaj gena
Keywords (english)
DNA methylation
progeria
liver cancer
bladder cancer
chromatin
gene expression
Language croatian
URN:NBN urn:nbn:hr:171:438147
Promotion 2022
Study programme Title: Biology of Neoplasms Study programme type: university Study level: postgraduate Academic / professional title: doktor/doktorica znanosti, područje biomedicine i zdravstvo (doktor/doktorica znanosti, područje biomedicine i zdravstvo)
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Access conditions Open access Embargo expiration date: 2024-07-22
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Created on 2022-09-07 10:18:38