{"id":255275,"date":"2022-06-03T17:55:27","date_gmt":"2022-06-03T16:55:27","guid":{"rendered":"https:\/\/zakrasnejsivimperk.cz\/?p=255275"},"modified":"2022-06-04T10:48:20","modified_gmt":"2022-06-04T09:48:20","slug":"veda-a-zdravi-sebeposkozeni-vlastni-dna-zvysuje-odolnost-rakovinnych-bunek-vuci-radiacni-terapii","status":"publish","type":"post","link":"https:\/\/zakrasnejsivimperk.cz\/?p=255275","title":{"rendered":"V\u011aDA A ZDRAV\u00cd: Odolnost rakovinn\u00fdch bun\u011bk v\u016f\u010di radia\u010dn\u00ed terapii se zvy\u0161uje po\u0161kozen\u00edm vlastn\u00ed DNA"},"content":{"rendered":"
\"\"
lustrace ukazuje funkci enzymu CAD, kter\u00fd specificky po\u0161kozuje DNA. (Autor: J. Benada)<\/figcaption><\/figure>\n
\n

 <\/p>\n

B\u011b\u017en\u011b pou\u017e\u00edvan\u00e1 radia\u010dn\u00ed terapie zab\u00edj\u00ed rakovinn\u00e9 bu\u0148ky t\u00edm, \u017ee zp\u016fsobuje rozs\u00e1hl\u00e9 po\u0161kozen\u00ed DNA v oza\u0159ovan\u00e9 tk\u00e1ni. Mezin\u00e1rodn\u00ed t\u00fdm v\u010detn\u011b n\u011bkolika v\u00fdzkumn\u00edk\u016f z \u00dastavu molekul\u00e1rn\u00ed genetiky Akademie v\u011bd \u010cR nyn\u00ed odhalil neo\u010dek\u00e1vanou strategii, jak se rakovinn\u00e9 bu\u0148ky smrti vyvolan\u00e9 radiac\u00ed vyh\u00fdbaj\u00ed \u2013 samy se d\u00e1le po\u0161kod\u00ed. Studii zve\u0159ejnil Science, jeden z nejpresti\u017en\u011bj\u0161\u00edch v\u011bdeck\u00fdch \u010dasopis\u016f.<\/h6>\n

\"\"Po\u0161kozen\u00ed DNA v lidsk\u00fdch bu\u0148k\u00e1ch se vyskytuje p\u0159irozen\u011b a je \u00fa\u010dinn\u011b opravov\u00e1no velk\u00fdm po\u010dtem opravn\u00fdch drah DNA. Tento proces v\u0161ak vy\u017eaduje \u010das. Z\u00e1vislost rakovinn\u00fdch bun\u011bk na rychl\u00e9m nekontrolovan\u00e9m bun\u011b\u010dn\u00e9m d\u011blen\u00ed je proto \u010din\u00ed neschopn\u00fdmi vypo\u0159\u00e1dat se s velk\u00fdm po\u0161kozen\u00edm DNA, kter\u00e9 zp\u016fsobuj\u00ed vysok\u00e9 d\u00e1vky z\u00e1\u0159en\u00ed. Radia\u010dn\u00ed terapie tak \u00fa\u010dinn\u011b zab\u00edj\u00ed n\u00e1dorov\u00e9 bu\u0148ky.<\/p>\n

I p\u0159es obecnou \u00fasp\u011b\u0161nost radiace se n\u00e1dory \u010dasto vracej\u00ed. Mechanismy, jimi\u017e se n\u00e1dorov\u00fdm bu\u0148k\u00e1m da\u0159\u00ed vyh\u00fdbat se bun\u011b\u010dn\u00e9 smrti po let\u00e1ln\u00edch d\u00e1vk\u00e1ch oz\u00e1\u0159en\u00ed, nejsou dob\u0159e zn\u00e1my, a proto rezistence v\u016f\u010di radia\u010dn\u00ed terapii z\u016fst\u00e1v\u00e1 zna\u010dnou v\u00fdzvou pro \u00fa\u010dinnou klinickou kontrolu n\u00e1dor\u016f.<\/p>\n

Sebepo\u0161kozen\u00edm proti smrti<\/h6>\n

T\u00fdm v\u011bdc\u016f p\u016fsob\u00edc\u00edch v D\u00e1nsku, \u010cesk\u00e9 republice, \u0160v\u00e9dsku, Kanad\u011b a \u0160v\u00fdcarsku, jen\u017e koordinuje Claus Storgaard S\u00f8rensen z Biotech Research and Innovation Centre, University of Copenhagen v D\u00e1nsku, zjistil, \u017ee v reakci na z\u00e1\u0159en\u00ed mohou n\u00e1dorov\u00e9 bu\u0148ky aktivovat endogenn\u00ed nukle\u00e1zu CAD \u2013 enzym, kter\u00fd rozkl\u00e1d\u00e1 nukleov\u00e9 kyseliny (v\u010detn\u011b DNA) v cel\u00e9m genomu. Zat\u00edmco p\u0159etrv\u00e1vaj\u00edc\u00ed po\u0161kozen\u00ed DNA je pro bu\u0148ku obecn\u011b \u0161patn\u00e9, mezin\u00e1rodn\u00ed v\u00fdzkumn\u00fd t\u00fdm uk\u00e1zal, \u017ee pot\u00e9, co radia\u010dn\u00ed terapie zp\u016fsob\u00ed po\u010d\u00e1te\u010dn\u00ed po\u0161kozen\u00ed DNA, si rakovinn\u00e9 bu\u0148ky zp\u016fsob\u00ed dal\u0161\u00ed zlomy DNA samy. T\u00edm \u00fa\u010dinn\u011b pozastav\u00ed sv\u016fj program d\u011blen\u00ed a bun\u011b\u010dn\u00fd cyklus v takzvan\u00e9m kontroln\u00edm bod\u011b G2 p\u0159ed za\u010d\u00e1tkem bun\u011b\u010dn\u00e9ho d\u011blen\u00ed, co\u017e jim poskytne \u010das na opravu zb\u00fdvaj\u00edc\u00edho po\u0161kozen\u00ed DNA.<\/p>\n

Tato velmi p\u0159ekvapiv\u00e1 a pon\u011bkud neintuitivn\u00ed strategie p\u0159id\u00e1v\u00e1n\u00ed c\u00edlen\u00fdch zlom\u016f DNA zlep\u0161uje \u0161anci rakovinn\u00fdch bun\u011bk smrteln\u00e9 d\u00e1vky z\u00e1\u0159en\u00ed p\u0159e\u017e\u00edt. Lze je p\u0159irovnat nap\u0159. k voj\u00e1k\u016fm ve v\u00e1lce, kte\u0159\u00ed se sami zran\u00ed, aby nemohli b\u00fdt posl\u00e1ni do boje.<\/p>\n

Konkr\u00e9tn\u011bji mechanismus vysv\u011btluje Ji\u0159\u00ed B\u00e1rtek z \u00dastavu molekul\u00e1rn\u00ed genetiky AV \u010cR (\u00daMG AV \u010cR), jeden z vedouc\u00edch autor\u016f v\u00fdzkumu: \u201eZat\u00edmco norm\u00e1ln\u00ed bu\u0148ky obvykle p\u0159eru\u0161\u00ed sv\u00e9 cykly d\u011blen\u00ed v tzv. kontroln\u00edm bod\u011b G1 f\u00e1ze, je tento mechanismus v\u011bt\u0161inou u rakovinn\u00fdch bun\u011bk defektn\u00ed. Proto hlavn\u00ed mo\u017enost\u00ed, jak zabr\u00e1nit katastrofick\u00e9mu bun\u011b\u010dn\u00e9mu d\u011blen\u00ed s po\u0161kozen\u00fdmi chromozomy, kter\u00e9 by d\u011bl\u00edc\u00ed se bu\u0148ky zabilo, je z\u016fstat v druh\u00e9m kontroln\u00edm bod\u011b G2 f\u00e1ze t\u011bsn\u011b p\u0159edt\u00edm, ne\u017e se bu\u0148ky za\u010dnou d\u011blit. Mnoho defekt\u016f zp\u016fsoben\u00fdch CAD \u201e\u0159\u00edk\u00e1\u201c n\u00e1dorov\u00fdm bu\u0148k\u00e1m, aby po\u010dkaly, dokud neoprav\u00ed nebezpe\u010dn\u011bj\u0161\u00ed zlomy DNA vyvolan\u00e9 radioterapi\u00ed.\u201c<\/em><\/p>\n

Zablokov\u00e1n\u00edm k pos\u00edlen\u00ed l\u00e9\u010dby<\/h6>\n

Auto\u0159i nav\u00edc zjistili, \u017ee tento jev je specifick\u00fd pro rakovinn\u00e9 bu\u0148ky. Ztr\u00e1ta aktivity CAD toti\u017e zp\u016fsob\u00ed, \u017ee rakovinn\u00e9 bu\u0148ky (proti norm\u00e1ln\u00edm bu\u0148k\u00e1m) jsou n\u00e1chyln\u00e9 k po\u0161kozen\u00ed, kter\u00e9 zp\u016fsobuje z\u00e1\u0159en\u00ed. \u201eTento neo\u010dek\u00e1van\u00fd nov\u00fd mechanismus skute\u010dn\u011b nazna\u010duje, jak se rakovinn\u00e9 bu\u0148ky mohou p\u0159izp\u016fsobit po\u0161kozen\u00ed DNA vyvolan\u00e9mu oz\u00e1\u0159en\u00edm, a t\u00edm se st\u00e1t odoln\u011bj\u0161\u00edmi v\u016f\u010di radioterapii,\u201c<\/em> vysv\u011btluj\u00ed Pavel Jan\u0161\u010d\u00e1k a V\u00e1clav Urban z \u00daMG AV \u010cR, kte\u0159\u00ed se na tomto objevu pod\u00edleli a jsou spoluautory nov\u00e9ho v\u011bdeck\u00e9ho \u010dl\u00e1nku.<\/p>\n

Souhrnn\u011b tyto poznatky oz\u0159ejmuj\u00ed mechanismus p\u0159e\u017eit\u00ed specifick\u00fd pro rakovinu. Ten by se dal v budoucnu zam\u011b\u0159it a vyu\u017e\u00edt ke zv\u00fd\u0161en\u00ed zranitelnosti n\u00e1dorov\u00fdch bun\u011bk v\u016f\u010di genotoxick\u00e9 l\u00e9\u010db\u011b rakoviny. Studie tak\u00e9 uk\u00e1zala, \u017ee experiment\u00e1ln\u00ed blokov\u00e1n\u00ed funkce CAD zp\u016fsobilo, \u017ee n\u00e1dorov\u00e9 bu\u0148ky (na rozd\u00edl od norm\u00e1ln\u00edch, zdrav\u00fdch bun\u011bk) byly v\u016f\u010di z\u00e1\u0159en\u00ed citliv\u011bj\u0161\u00ed, co\u017e nazna\u010duje, jak by tyto nov\u00e9 poznatky mohly b\u00fdt vyu\u017eity ke zlep\u0161en\u00ed v\u00fdsledk\u016f radioterapie v budoucnu.<\/p>\n

(tzav\u010dr)<\/strong><\/p>\n

\n

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 <\/p>\n","protected":false},"excerpt":{"rendered":"

  B\u011b\u017en\u011b <\/p>\n","protected":false},"author":2,"featured_media":255276,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"gallery","meta":{"footnotes":""},"categories":[128,174],"tags":[],"jetpack_featured_media_url":"https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/05\/28\/CAD.png","_links":{"self":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts\/255275"}],"collection":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=255275"}],"version-history":[{"count":4,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts\/255275\/revisions"}],"predecessor-version":[{"id":255710,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts\/255275\/revisions\/255710"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/media\/255276"}],"wp:attachment":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=255275"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=255275"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=255275"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}