【摘要】 目的探讨¹³¹I-17-丙烯胺基-17-去甲氧基格尔德霉素（17-AAG）对人乳腺癌细胞生长的影响及其相关机制。方法采用过氧化氢标记法制备¹³¹I-17-AAG。细胞杀伤实验分为5组:二甲基亚砜（DMSO）对照（A）组,Na¹³¹I 370 kBq（B）组,17-AAG 2.5 mg/L（C）组,¹³¹I-17-AAG 370 kBq（D）组,¹³¹I-17-AAG 370 kBq+17-AAG 2.5 mg/L（E）组。用四甲基偶氮唑蓝（MTT）法检测各种药物对人乳腺癌细胞 MCF-7的生长抑制作用,流式细胞术分析细胞凋亡及细胞周期变化,RT-PCR 检测药物处理前后 MCF-7细胞中 Akt2基因的 mRNA 表达情况。结果 ¹³¹I-17-AAG 的标记率为83%,放化纯为96.6%,比活度为1.48×10⁵MBq/μmol。各组药物对细胞的杀伤呈时间效应,随着时间的延长,细胞的抑制率都呈明显上升趋势,尤以 E 组趋势明显。A～E组药物作用48 h 后,通过亚 G1峰检测 MCF-7细胞凋亡率分别为（1.54±0.13）%,（5.72±1.05）%,（12.97±1.44）%,（20.65±1.36）%,（35.39±4.15）%,各组细胞凋亡率差异有统计学意义（P 均<0.05）。C 组,D 组及 E 组Akt2基因的 mRNA 表达均比 A 组降低,其中 E 组降低尤为明显。结论 ¹³¹I-17AAG 能够抑制 MCF-7细胞的生长并促进其凋亡,且能有效抑制 Akt2基因的 mRNA 表达,和17-AAG 联合应用能够增强肿瘤细胞对放疗的敏感性。更多还原

【Abstract】 Objective 17-allylamino-17-demethoxygeldanamyein（17-AAG）is a less toxic analogue of geldanamycin（GA）that retains the tumoricidal features of GA.Same as its parent compound,17-AAG in- hibits several signaling pathways through binding to heat shock protein（HSP）90,which results in destabili- zation of signaling complexes and degradation of client proteins in a variety of tumor cell growth.Treatment with 17-AAG was effective to inhibit tumor growth and induce apoptosis in colon cancer,glioblastoma,and breast cancer cell lines.This study aimed at exploring the anti-proliferation effects and mechanism of ¹³¹I la- beled 17-AAG on human breast cancer cell line MCF-7.Methods ¹³¹I-17-AAG was prepared by the reaction of 17-AAG with Na¹³¹I in the presence of hydrogen peroxide.The MCF-7 cells were divided into 5 groups with different additional drugs:group A,dimethyl sulfoxide（DMSO）;group B,370 kBq Na¹³¹I;group C,2.5 mg/L 17-AAG;group D,370 kBq ¹³¹I-AAG;group E,370 kBq¹³¹I-17-AAG+2.5 mg/L 17-AAG.3- （4,5-dimethylthiazol-2-yl）-2,5,diphenylte-trazolium bromide（MTF）assay was used to evaluate the effect of growth inhibition of MCF-7 cells.Cell cycle and apoptosis were analyzed by flow cytometry.The change of the expression of Akt2 mRNA in MCF-7 cells was examined by RT-PCR.Results The labeling yield of ¹³¹I-17-AAG was 83%.The radiochemical purity of ¹³¹I-17-AAG after purification was 96.6%.The specific activity was 1.48 x 10⁵ MBq/μmol.All drugs could significantly inhibit the growth of MCF-7 cells in vitro as the duration lasts longer,especially for group E.After 48 h,sub-G1 peaks detected by flow cytometry were（1.54±0.13）%,（5.72±1.05）%,（12.97±1.44）%,（20.65±1.36）%,（35.39±4.15）% for group A,B,C,D and E,respectively.The experimental groups（B～E）were all significantly higher than the control group（A,all P<0.05）.The expression of Akt2 mRNA in treated MCF-7 cells（groups C～E） were all lower than that of the control group（A）,especially for group E.Conclusions ¹³¹I-17-AAG could suppress the growth of human breast cancer cell line MCF-7 and hasten the apoptosis.It could significantly suppress the expression of Akt2 mRNA.Combined with 17-AAG,¹³¹I-17-AAG could improve the effect of radiotherapy.更多还原