The indole-3-carbinol cyclic tetrameric derivative CTet inhibits cell proliferation via overexpression of p21/CDKN1A in both estrogen receptor-positive and triple-negative breast cancer cell lines
The indole-3-carbinol cyclic tetrameric derivative CTet inhibits cell proliferation via overexpression of p21/CDKN1A in both estrogen receptor-positive and triple-negative breast cancer cell lines
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DOI：
10.1186/bcr2855
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发表时间：
2011-01-01
影响因子：
7.4
通讯作者：
Magnani, Mauro
中科院分区：
文献类型：
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作者：
De Santi, Mauro;Galluzzi, Luca;Magnani, Mauro
摘要：吲哚-3-甲醇（I3C）是十字花科蔬菜中硫代葡萄糖苷的自溶产物，其二聚体衍生物（3,3′-DIM）已被认为是预防乳腺癌发生发展的有前景的药物。我们最近表明，在γ -环糊精（γ - cd）中配制的I3C环四聚体衍生物CTet有效地抑制了乳腺癌细胞系的细胞增殖。本研究旨在分析体外抑制细胞增殖的机制，并在异种移植研究中评估CTet的体内抗肿瘤活性。方法：将雌激素受体阳性的MCF-7和三阴性的MDA-MB-231乳腺癌细胞株暴露于CTet中，以评估细胞周期扰动（碘化丙烯染色和细胞荧光法获取）、自噬形态学特征的诱导（免疫荧光法检测LC3b自噬体标志物和LAMP2a溶酶体标志物的共定位）和蛋白质表达的变化（免疫印迹和基于微阵列的基因表达分析）。为了检验CTet在体内的作用，将MCF-7细胞接种的雌性胸腺裸鼠以5 mg/kg/天的CTet灌胃治疗，连续5天/周，连续2周，并对肿瘤肿块进行体外监测。结果：CTet诱导两种细胞系在G2/M期积累，但没有诱导凋亡反应的证据。在三阴性MDA-MB-231细胞中，4 μ M的CTet作用8小时后，MCF-7细胞的自噬溶酶体活性显著上调，而观察MCF-7细胞的自噬特征需要达到最高的CTet浓度。在MCF-7和p53突变体MDA-MB-231细胞中，Akt活性和p53非依赖性p21/CDKN1A和GADD45A过表达的抑制被确定为CTet活性的主要分子事件。在体内，CTet能够显著抑制MCF-7异种移植到裸鼠体内的生长，而不会对体重或血液学参数产生不利影响。结论：我们的数据支持CTet与γ - cd联合配制，作为激素反应性和三阴性乳腺肿瘤的一种有前景的可注射抗癌药物。
Introduction: Indole-3-carbinol (I3C), an autolysis product of glucosinolates present in cruciferous vegetables, and its dimeric derivative (3,3'-DIM) have been indicated as promising agents in preventing the development and progression of breast cancer. We have recently shown that I3C cyclic tetrameric derivative CTet formulated in gamma-cyclodextrin (gamma-CD) efficiently inhibited cellular proliferation in breast cancer cell lines. This study aims to analyze the mechanisms involved in the in vitro inhibition of cell proliferation and to evaluate the in vivo antitumor activity of CTet in a xenograft study.Methods: Estrogen receptor-positive MCF-7 and triple-negative MDA-MB-231 breast cancer cell lines were exposed to CTet to evaluate cell cycle perturbation (propidium iodide staining and cytofluorimetric acquisition), induction of autophagic morphological features (co-localization of LC3b autophagosome marker and LAMP2a lysosome marker by immunofluorescence) and changes in protein expression (immunoblot and microarray-based gene expression analyses). To test the in vivo efficacy of CTet, female athymic nude mice inoculated with MCF-7 cells were i.p. treated with 5 mg/kg/day of CTet for five days/week for two weeks and the tumor mass was externally monitored.Results: CTet induced accumulation in G2/M phase without evidence of apoptotic response induction in both cell lines tested. In triple-negative MDA-MB-231 the autophagic lysosomal activity was significantly up-regulated after exposure to 4 mu M of CTet for 8 hours, while the highest CTet concentration was necessary to observe autophagic features in MCF-7 cells. The inhibition of Akt activity and p53-independent p21/CDKN1A and GADD45A overexpression were identified as the main molecular events responsible for CTet activity in MCF-7 and p53-mutant MDA-MB-231 cells. In vivo, CTet administration was able to significantly inhibit the growth of MCF-7 xenotransplanted into nude mice, without adverse effect on body weight or on haematological parameters.Conclusions: Our data support CTet formulated with gamma-CD as a promising and injectable anticancer agent for both hormone-responsive and triple-negative breast tumors.