CAJ | 학술논문

背景与目的:放射治疗在结直肠腺癌综合治疗中发挥着重要的作用,与非肿瘤干细胞(non-cancer stem cells,non-CSCs)相比,肿瘤干细胞(cancer stemcells,CSCs)更具放射抵抗性,并且是影响放射治疗效果的重要因素之一.本研究旨在探讨人结直肠腺癌CSCs特征性染色体结构及组蛋白修饰方式对肿瘤放射抵抗效应的作用.方法:收集人结直肠癌手术标本并建立裸鼠皮下移植瘤模型.免疫组化检测人手术标本和异种移植动物肿瘤的组织来源.流式细胞仪分选人结直肠腺癌标本与移植瘤模型中放射干预前后CSCs(CD133~+)与non-CSCs(CD133~-),并检测CSCs表面标志物CD133的表达,利用免疫荧光染色检测CD133~+及CD133~-细胞核中异染色质标记物(H3K9me3,HP1-α,H3K4me1)和常染色质标志物(H3K4me3)的表达情况.结果:人手术标本和异种移植动物肿瘤的组织来源相同.人结直肠腺癌中CSCs与non-CSCs染色质结构存在明显差异.CD133~+细胞染色质为致密斑块状结构,CD133~-细胞染色质结构则明显呈疏松片状或网格状,免疫荧光染色显示CSCs细胞核中存在的致密斑块状结构为异染色质成分.行10 Gy单次大剂量放射干预1h和24 h后发现,结直肠腺癌CSCs异染色质区域出现明显空泡状缺损现象,non-CSCs染色质除结构稍疏松外无其他明显改变;放射后96 h和144 h CSCs异染色质空泡状缺损普遍得到修复,并逐渐恢复至放射干预前的致密斑块状结构.结论:CSCs在人结直肠腺癌放射抵抗效应中发挥作用,其机制可能与异染色质形成及组蛋白的甲基化修饰紧密相关.
배경여목적:방사치료재결직장선암종합치료중발휘착중요적작용,여비종류간세포(non-cancer stem cells,non-CSCs)상비,종류간세포(cancer stemcells,CSCs)경구방사저항성,병차시영향방사치료효과적중요인소지일.본연구지재탐토인결직장선암CSCs특정성염색체결구급조단백수식방식대종류방사저항효응적작용.방법:수집인결직장암수술표본병건립라서피하이식류모형.면역조화검측인수술표본화이충이식동물종류적조직래원.류식세포의분선인결직장선암표본여이식류모형중방사간예전후CSCs(CD133~+)여non-CSCs(CD133~-),병검측CSCs표면표지물CD133적표체,이용면역형광염색검측CD133~+급CD133~-세포핵중이염색질표기물(H3K9me3,HP1-α,H3K4me1)화상염색질표지물(H3K4me3)적표체정황.결과:인수술표본화이충이식동물종류적조직래원상동.인결직장선암중CSCs여non-CSCs염색질결구존재명현차이.CD133~+세포염색질위치밀반괴상결구,CD133~-세포염색질결구칙명현정소송편상혹망격상,면역형광염색현시CSCs세포핵중존재적치밀반괴상결구위이염색질성분.행10 Gy단차대제량방사간예1h화24 h후발현,결직장선암CSCs이염색질구역출현명현공포상결손현상,non-CSCs염색질제결구초소송외무기타명현개변;방사후96 h화144 h CSCs이염색질공포상결손보편득도수복,병축점회복지방사간예전적치밀반괴상결구.결론:CSCs재인결직장선암방사저항효응중발휘작용,기궤제가능여이염색질형성급조단백적갑기화수식긴밀상관.
Background and Objective:Radiotherapy(RT)is a major nonsurgical modality in the comprehensive treatment for colorectal adenocarcinoma.The radioresistance of cancer stem cells(CSCs)is a key factor that influences therapeutic effectiveness.This study was to investigate the effects of specific chromosome structure and histone modification in CSCs in colorectal adenocarcinoma radioresistance.Methods:Samples were collected from resected human colorectaI adenocarcinomas.Subcutaneous colorectal cancer model was established in nude mice.Immunohistochemistry showed that xenografts generated from bulk colorectaI cancer cells resembled the original tumor specimen.Flow cytometry was performed to sort CSCs (CD133~+)and non-CSCs(CD133~-)from both resected samples of colorectal adenocarcinoma and xenograft before and after high single-dose radiation.The markers labeling heterochromatin(H3K9me3,HP1-α,and H3K4me1)and euchromatin(H3K4me3)in CD133~+ and CD133-nucleus were detected by immunoflurescence.Results:There was distinct difference in chromatin structure between colorectaI CSCs(CD133~+)and non-CSCs (CD133~-).The chromatin displayed compact patches in CD133~+ nucleus,but loosely latticed structure in CD133-nucleus:immunoflurescence verified that the compact patches existing in CSCs was generated from heterochromatin construction.In addition.the vacuole-like defect in heterochromatin regions of CSCs was observed within 24 h after exposure to 10 gray(Gy)single-dose RT.Interestingly.this phenomenon was repaired from 96 h.and recovered to dense plaque structure in heterochromatin regions of CSCs after 144 h.However,no significant difference in non-CSCs was observed after RT exception for a loose chromatin structure.Conclusions:CSCs play a role in radiosensitivity in colorectal cancer.The mechanism may be related to heterchromatin formation and histone methylation.