125I粒子植入对人肝癌细胞裸鼠HepG2 移植瘤的杀伤作用及其分子机制

目的探讨不同剂量^125I粒子组织间植入对人肝癌细胞裸鼠HepG2移植瘤的杀伤作用及其分子机制。方法构建20个人肝癌细胞HepG2的裸鼠移植瘤模型,随机分为4组,每组5只。3个治疗组分别接受18.5 MBq、29.6 MBq、37.0 MBq的^125I粒子治疗,对照组不接受治疗。采用经皮肿瘤组织直接植入的方式分别将不同剂量^125I粒子植入各治疗组小鼠的瘤体内,每只小鼠瘤体内植入1粒^125I粒子。至治疗第28天处死小鼠,取肿瘤组织行常规病理学和免疫组织化学检查检测Bcl-2和Bax的表达情况。结果光镜下各治疗组肿瘤细胞呈不同程度凝固性坏死,周围广泛纤维化;对照组肿瘤细胞丰富,呈增殖样生长。免疫组织化学结果显示各治疗组中Bax的表达均高于对照组,并随^125I粒子剂量的增加而逐渐增加;各治疗组中Bcl-2的表达及Bcl-2/Bax比值均低于对照组,并随^125I粒子剂量的增加而逐渐减少。Bcl-2、Bax阳性率及Bcl-2/Bax比值在各治疗组与对照组间及各治疗组间的差异均有统计学意义（P均〈0.05）。结论^125I粒子组织间植入治疗可通过下调Bcl-2/Bax的比值促进裸鼠HepG2肝癌细胞凋亡,从而抑制肿瘤的生长;其诱导肝癌细胞凋亡的程度及抑制肿瘤生长的效果均在一定剂量范围内与剂量成正比。

Killing effect and molecular mechanism of 125I seeds interstitial brachytherapy on human hepatocarcinoma cell HepG2 of transplanted tumor in nude mice

Objective To investigate the killing effect and molecular mechanism of different doses of 125I seed interstitial brachytherapy for human hepatoma HepG2 cells in nude mice transplanted tumor.Methods Twenty nude mice bearing human hepatoma HepG2 cells were randomly divided into 4 groups(each n=5) and given 125I seed interstitial brachytherapy at different doses including 18.5 MBq 125I,29.6 MBq 125I,37.0 MBq125I and 0(the control group),respectively.125I seeds were percutaneously implanted into tumors,each mou...