Son d\u00f6nemde St. Jude \u00c7ocuk Ara\u015ft\u0131rma Hastanesi\u2019nde ger\u00e7ekle\u015ftirilen \u00f6nc\u00fc bir \u00e7al\u0131\u015fma, y\u00fcksek riskli pediatrik beyin t\u00fcm\u00f6r\u00fc t\u00fcrlerinden biri olan SHH-medulloblastoma\u2019n\u0131n molek\u00fcler temellerini ayd\u0131nlatarak, hedefe y\u00f6nelik umut vadeden bir tedavi yakla\u015f\u0131m\u0131n\u0131 g\u00fcndeme getirdi. Bu \u00e7al\u0131\u015fmada \u00f6zellikle ELP1 geninde kal\u0131tsal mutasyonlar\u0131 bulunan \u00e7ocuklarda ortaya \u00e7\u0131kan bu agresif t\u00fcm\u00f6r\u00fcn geli\u015fim mekanizmas\u0131 incelendi. Ara\u015ft\u0131rmac\u0131lar, ELP1 eksikli\u011finin olu\u015fturdu\u011fu biyokimyasal yollar\u0131 \u00e7\u00f6z\u00fcmleyerek, potansiyel bir farmakolojik stratejiyi tan\u0131mlad\u0131 ve bu yakla\u015f\u0131mla tedavi paradigmas\u0131n\u0131n de\u011fi\u015ftirilebilece\u011fi, hayatta kal\u0131m oranlar\u0131n\u0131n art\u0131r\u0131labilece\u011fi belirtildi.<\/p>\n
Medulloblastoma, \u00f6zellikle sonic hedgehog (SHH) sinyal yolundaki bozukluklarla karakterize olan bir beyin t\u00fcm\u00f6r\u00fc olup, \u00e7ocukluk \u00e7a\u011f\u0131 kanser \u00f6l\u00fcmlerinde \u00f6nemli bir yer tutmaktad\u0131r. Klinik \u00f6nemi b\u00fcy\u00fck olmas\u0131na ra\u011fmen, kal\u0131tsal genetik varyantlar\u0131n hastal\u0131k duyarl\u0131l\u0131\u011f\u0131na katk\u0131s\u0131 uzun zamand\u0131r tam olarak anla\u015f\u0131lamam\u0131\u015ft\u0131. St. Jude\u2019daki ara\u015ft\u0131rma ekibi bu zorlu\u011fun \u00fcstesinden gelmek i\u00e7in ELP1 genine odakland\u0131. \u00d6nceden kanser yatk\u0131nl\u0131\u011f\u0131 ile ili\u015fkilendirilmi\u015f olan ancak t\u00fcm\u00f6r geli\u015fimindeki rol\u00fc belirsiz kalan bu genin, medulloblastoma patogenezindeki etkileri ara\u015ft\u0131r\u0131ld\u0131.<\/p>\n
ELP1 geni v\u00fccutta pek \u00e7ok dokuda ifade edilirken, \u0130\u015fin ilgin\u00e7 k\u0131sm\u0131, bu genin i\u015flev kayb\u0131 \u00e7ocuklarda sadece SHH-medulloblastoma geli\u015fme riskini art\u0131rmaktad\u0131r. Bu \u00f6zg\u00fcll\u00fck ara\u015ft\u0131rmac\u0131lar\u0131 \u015fa\u015f\u0131rtarak, fonksiyonel ELP1 geninden yoksun geli\u015fmi\u015f fare modelleri olu\u015fturularak \u00f6zellikle serebellumdaki gran\u00fcl n\u00f6ron progenit\u00f6r h\u00fccreleri \u00fczerinde bu genin etkileri derinlemesine incelendi. B\u00f6ylece ELP1 kayb\u0131n\u0131n t\u00fcm\u00f6r s\u00fcrecinde p53 t\u00fcm\u00f6r bask\u0131lay\u0131c\u0131 proteinin aktivitesinin azalmas\u0131yla ba\u011flant\u0131s\u0131 ba\u015far\u0131yla tespit edildi.<\/p>\n
\u201cGenomun koruyucusu\u201d olarak an\u0131lan p53 proteini, zarar g\u00f6rm\u00fc\u015f h\u00fccrelerde \u00e7o\u011falmay\u0131 durdurarak apoptozu tetikleyen ve b\u00f6ylece kanser geli\u015fimini engelleyen kritik bir molek\u00fcld\u00fcr. \u00c7o\u011fu kanserde p53\u2019\u00fcn i\u015flev kayb\u0131 do\u011frudan mutasyonlarla ger\u00e7ekle\u015firken, SHH-medulloblastoma ba\u011flam\u0131nda ELP1 kayb\u0131 p53\u2019\u00fcn genetik mutasyona u\u011framadan fonksiyonunun dolayl\u0131 yoldan bask\u0131lanmas\u0131na neden olmaktad\u0131r. Bu durum, geli\u015fmekte olan serebellar n\u00f6ronlarda t\u00fcm\u00f6r olu\u015fumunu kolayla\u015ft\u0131rmaktad\u0131r.<\/p>\n
Ara\u015ft\u0131rman\u0131n \u00f6nemli bir \u00e7\u0131kt\u0131s\u0131 olarak, ELP1 eksikli\u011finin p53\u2019\u00fcn biyolojik etkisini ortadan kald\u0131ran MDM2 adl\u0131 E3 ubiquitin ligaz enzim aktivitesinin artmas\u0131na yol a\u00e7t\u0131\u011f\u0131 belirlendi. MDM2, p53\u2019\u00fc hedef al\u0131p y\u0131k\u0131lmas\u0131n\u0131 sa\u011flad\u0131\u011f\u0131 i\u00e7in, bu mekanizman\u0131n engellenmesi p53 i\u015flevinin tekrar kazan\u0131lmas\u0131 ad\u0131na kritik bir hedef olu\u015fturuyor. B\u00f6ylelikle, MDM2 aktivitesini durduracak terap\u00f6tik yakla\u015f\u0131mlar \u00fczerinde yo\u011funla\u015fma ba\u015flad\u0131.<\/p>\n
Ara\u015ft\u0131rmac\u0131lar, ELP1 fonksiyon kaybunu yans\u0131tan genetik fare modellerinde MDM2 inhibit\u00f6rleri uygulad\u0131klar\u0131nda p53 aktivitesinde \u00f6nemli bir geri d\u00f6n\u00fc\u015f g\u00f6zlemlediler. Aktif p53 proteini t\u00fcm\u00f6r b\u00fcy\u00fcmesini kontroll\u00fc hale getirip, hayatta kalma s\u00fcresini anlaml\u0131 \u00f6l\u00e7\u00fcde art\u0131rd\u0131. Bu sonu\u00e7, p53\u2019\u00fcn bask\u0131lanmas\u0131n\u0131n ELP1 eksikli\u011fi ba\u011flam\u0131nda t\u00fcm\u00f6r geli\u015fimi i\u00e7in kritik oldu\u011funu do\u011frularken, MDM2 inhibisyonunun hedefe y\u00f6nelik etkili bir tedavi alternatifi oldu\u011funu da kan\u0131tlad\u0131.<\/p>\n
Klinik a\u00e7\u0131dan \u00f6nem ta\u015f\u0131yan bu bulgular\u0131n de\u011ferini art\u0131ran bir di\u011fer fakt\u00f6r, hali haz\u0131rda pek \u00e7ok kanser t\u00fcr\u00fcnde MDM2 inhibit\u00f6rlerinin klinik denemelerde kullan\u0131l\u0131yor olmas\u0131d\u0131r. Bu da s\u00f6z konusu ajanlar\u0131n pediatrik beyin t\u00fcm\u00f6rlerinde, \u00f6zellikle ELP1 eksikli\u011fi bulunan SHH-medulloblastoma hastalar\u0131nda daha k\u0131sa s\u00fcrede uygulanabilir hale gelmesi anlam\u0131na gelmektedir. B\u00f6ylece hedefe y\u00f6nelik tedavide \u00f6nemli bir h\u0131z kazan\u0131lm\u0131\u015ft\u0131r.<\/p>\n
\u00c7al\u0131\u015fman\u0131n \u00f6nemi terap\u00f6tik etkilerinin \u00f6tesinde tedavinin g\u00fcvenlik profiline olan katk\u0131lar\u0131nda da kendini g\u00f6stermektedir. G\u00fcn\u00fcm\u00fczde radyasyon ve kemoterapi esas\u0131yla uygulanan medulloblastoma tedavileri, uzun vadede n\u00f6rokognitif bozukluklar gibi ciddi yan etkilere yol a\u00e7abilmektedir. MDM2 inhibit\u00f6rleri gibi hedefe y\u00f6nelik ajanlar ise \u00f6zellikle \u00e7ocuklarda geli\u015fimi olumsuz etkileme potansiyeli d\u00fc\u015f\u00fck, daha spesifik ve yan etkileri s\u0131n\u0131rl\u0131 tedavi se\u00e7enekleri sunmaktad\u0131r.<\/p>\n
Bu kapsaml\u0131 ara\u015ft\u0131rma, n\u00f6ro-onkoloji, geli\u015fimsel n\u00f6robiyoloji, kanser geneti\u011fi ve farmakoloji alanlar\u0131n\u0131n uluslararas\u0131 d\u00fczeyde i\u015f birli\u011fi yapt\u0131\u011f\u0131 disiplinleraras\u0131 \u00e7aban\u0131n \u00fcr\u00fcn\u00fc olarak St. Jude ekibi taraf\u0131ndan ger\u00e7ekle\u015ftirildi. \u00c7al\u0131\u015fmada Avustralya\u2019daki Queensland \u00dcniversitesi, Almanya\u2019daki Kanser Ara\u015ft\u0131rma Merkezi (DKFZ) ve \u0130svi\u00e7re\u2019deki EPFL gibi d\u00fcnyan\u0131n sayg\u0131n ara\u015ft\u0131rma kurumlar\u0131ndan bilim insanlar\u0131 da yer ald\u0131. Bu i\u015f birli\u011fi, \u00e7ocukluk d\u00f6nemi beyin t\u00fcm\u00f6rlerinin \u00e7\u00f6z\u00fcm\u00fcne y\u00f6nelik k\u00fcresel bilimsel dayan\u0131\u015fmay\u0131 g\u00f6stermektedir.<\/p>\n
\u00c7al\u0131\u015fman\u0131n finansal destek\u00e7isi olarak St. Baldrick\u2019s Vakf\u0131, Ulusal Kanser Enstit\u00fcs\u00fc (NCI), Deutsche Forschungsgemeinschaft (DFG) ve ALSAC gibi kurumlar kritik rol oynad\u0131. Bu kurulu\u015flar, \u00e7ocukluk \u00e7a\u011f\u0131 kanserlerinde hem ya\u015fam s\u00fcresini art\u0131rmaya hem de ya\u015fam kalitesini y\u00fckseltmeye y\u00f6nelik yenilik\u00e7i ara\u015ft\u0131rmalar\u0131n \u00f6n\u00fcn\u00fc a\u00e7makta, bilim insanlar\u0131n\u0131n cesur ve yarat\u0131c\u0131 projelerine olanak sa\u011flamaktad\u0131r.<\/p>\n
Gelece\u011fe y\u00f6nelik planlar aras\u0131nda, laboratuvardaki bu heyecan verici bulgular\u0131n klinik deneme a\u015famalar\u0131na aktar\u0131lmas\u0131 yer al\u0131yor. MDM2 inhibit\u00f6rlerinin ba\u015fka kanser t\u00fcrlerinde halihaz\u0131rda test edilmekte oldu\u011fu g\u00f6z \u00f6n\u00fcne al\u0131nd\u0131\u011f\u0131nda, bu ajanlar\u0131n SHH-medulloblastoma hastalar\u0131nda de\u011ferlendirilmesi beklenenden daha h\u0131zl\u0131 bir \u015fekilde m\u00fcmk\u00fcn olacak. Bu geli\u015fme, pediatrik beyin t\u00fcm\u00f6rlerinde tedavi se\u00e7eneklerini \u00f6nemli \u00f6l\u00e7\u00fcde geni\u015fletecek, hastalar i\u00e7in yeni umutlar yaratacakt\u0131r.<\/p>\n
Bilimsel a\u00e7\u0131dan da ara\u015ft\u0131rma, t\u00fcm v\u00fccutta ifade edilen bir genin neden sadece belirli bir doku ve hastal\u0131k ba\u011flam\u0131nda kanser geli\u015fimine katk\u0131da bulundu\u011funun karma\u015f\u0131k molek\u00fcler etkile\u015fimlerle a\u00e7\u0131klanmas\u0131na katk\u0131 sa\u011flad\u0131. Bu durum, kanser geneti\u011finin inceliklerini ortaya koymakta ve t\u00fcm\u00f6r bask\u0131lay\u0131c\u0131 genlerin mutasyon d\u0131\u015f\u0131nda farkl\u0131 d\u00fczenleyici mekanizmalarla ne denli etkilenebilece\u011fini g\u00f6stermektedir.<\/p>\n
Sonu\u00e7 olarak, St. Jude\u2019dan gelen bu \u00f6nc\u00fc \u00e7al\u0131\u015fma temel bilim ile hassas t\u0131bb\u0131 birle\u015ftirerek, pediatrik bir hastal\u0131kta kritik genetik yatk\u0131nl\u0131k fakt\u00f6r\u00fcn\u00fc anlamak ve terap\u00f6tik olarak de\u011ferlendirmek a\u00e7\u0131s\u0131ndan b\u00fcy\u00fck bir ad\u0131m att\u0131. Ara\u015ft\u0131rmac\u0131lar, \u00e7ocukluk \u00e7a\u011f\u0131 beyin kanserlerinde daha g\u00fcvenli, etkili ve ki\u015fiye \u00f6zel tedavi olanaklar\u0131 yarat\u0131lmas\u0131n\u0131 hedefleyerek, her etkilenen k\u00fc\u00e7\u00fck hayat\u0131n gelece\u011fini koruma yolunda umut verici bir geli\u015fmenin alt\u0131n\u0131 \u00e7izdi.<\/p>\n
—<\/p>\n
**Ara\u015ft\u0131rma Konusu**: Pediatrik SHH-medulloblastoma; ELP1 geni eksikli\u011fi; t\u00fcm\u00f6r bask\u0131lay\u0131c\u0131 p53 d\u00fczenlenmesi; MDM2 inhibisyonu ile hedefe y\u00f6nelik terapi.
\n**Makale Ba\u015fl\u0131\u011f\u0131**: Study reveals targetable mechanism behind high-risk predisposition gene in pediatric medulloblastoma
\n**Haberin Yay\u0131n Tarihi**: May\u0131s 15, 2025
\n**Web References**:
\n– St. Jude Center of Excellence in Neuro-Oncology Sciences (CENOS): https:\/\/www.stjude.org\/research\/centers-of-excellence\/cenos.html
\n– Paul Northcott Lab: https:\/\/www.stjude.org\/research\/labs\/northcott-lab.html
\n– St. Jude Progress digital magazine: https:\/\/blogs.stjude.org\/progress.html
\n– St. Jude official website: https:\/\/www.stjude.org\/
\n**Doi Referans**: 10.1016\/j.ccell.2025.04.014
\n**Resim Credits**: St. Jude Children\u2019s Research Hospital
\n**Anahtar Kelimeler**: Medulloblastoma, T\u00fcm\u00f6r bask\u0131lay\u0131c\u0131lar, Pediatrik beyin t\u00fcm\u00f6rleri, ELP1 geni, p53, MDM2, Hedefe y\u00f6nelik tedavi, Kanser geneti\u011fi<\/p>\n","protected":false},"excerpt":{"rendered":"
Son d\u00f6nemde St. Jude \u00c7ocuk Ara\u015ft\u0131rma Hastanesi\u2019nde ger\u00e7ekle\u015ftirilen \u00f6nc\u00fc bir \u00e7al\u0131\u015fma, y\u00fcksek riskli pediatrik beyin t\u00fcm\u00f6r\u00fc t\u00fcrlerinden biri olan SHH-medulloblastoma\u2019n\u0131n molek\u00fcler temellerini ayd\u0131nlatarak, hedefe y\u00f6nelik umut vadeden bir tedavi yakla\u015f\u0131m\u0131n\u0131 g\u00fcndeme getirdi. Bu \u00e7al\u0131\u015fmada \u00f6zellikle ELP1 geninde kal\u0131tsal mutasyonlar\u0131 bulunan \u00e7ocuklarda ortaya \u00e7\u0131kan bu agresif t\u00fcm\u00f6r\u00fcn geli\u015fim mekanizmas\u0131 incelendi. Ara\u015ft\u0131rmac\u0131lar, ELP1 eksikli\u011finin olu\u015fturdu\u011fu biyokimyasal yollar\u0131…<\/p>\n","protected":false},"author":1,"featured_media":6081,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[28],"tags":[8500,8502,8501,8498,8499],"tmauthors":[],"class_list":{"0":"post-6080","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-kanser","8":"tag-elp1-gen-mutasyonlari-ve-beyin-tumorleri","9":"tag-mdm2-inhibitorleri-ile-kanser-tedavisi","10":"tag-p53-tumor-baskilayici-proteini-rolu","11":"tag-pediatrik-medulloblastom-tedavi-stratejileri","12":"tag-shh-medulloblastoma-genetik-mekanizmalari"},"jetpack_featured_media_url":"https:\/\/haber360.com\/wp-content\/uploads\/2025\/05\/Pediatrik-Medulloblastomda-Hedeflenebilir-Gen-Mekanizmasi-1747335637.jpg","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/posts\/6080","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/comments?post=6080"}],"version-history":[{"count":0,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/posts\/6080\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/media\/6081"}],"wp:attachment":[{"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/media?parent=6080"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/categories?post=6080"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/tags?post=6080"},{"taxonomy":"tmauthors","embeddable":true,"href":"https:\/\/haber360.com\/index.php\/wp-json\/wp\/v2\/tmauthors?post=6080"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}