Indole-3-carbinol and diindolylmethane induce apoptosis of human cervical cancer cells and in murine HPV16-transgenic preneoplastic cervical epithelium
Indole-3-carbinol and diindolylmethane induce apoptosis of human cervical cancer cells and in murine HPV16-transgenic preneoplastic cervical epithelium
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DOI：
10.1093/jn/131.12.3294
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发表时间：
2001-12-01
影响因子：
4.2
通讯作者：
Carter, TH
中科院分区：
文献类型：
--
作者：
Chen, DZ;Qi, M;Carter, TH
饮食吲哚-3-甲醇（I3 C）对宫颈癌和喉乳头状瘤病都有临床益处，并在体外引起乳腺癌细胞凋亡。我们问是否I3 C和它的主要酸催化缩合产物二吲哚甲烷（DIM），这是在胃中产生的十字花科蔬菜消费后，可以诱导宫颈癌细胞系的凋亡。我们还询问是否可以在体内观察到这种效果。在体外实验中，I3 C和DIM均引起三种宫颈癌细胞系中DNA链断裂的积累。细胞凋亡的诱导证实了核形态，核小体渗漏，改变细胞质膜通透性和半胱天冬酶3激活。I3 C和DIM均未引起正常人角质形成细胞凋亡。在C33 A宫颈癌细胞中，DIM比I3 C更有效[在线粒体功能测定中，活细胞数为未处理培养物中活细胞数的50%的剂量（LD 50）= DIM为50-60 μ mol/L，I3 C为200 μ mol/L]，并且作用更快。此外，I3 C以时间和剂量依赖性方式降低Bcl-2蛋白。在HPV 16转基因小鼠中，在慢性雌二醇暴露后发生宫颈癌，通过TdT介导的dUTP缺口末端标记染色和仅在暴露于17 β-雌二醇（E-2）并喂食I3 C的小鼠中通过活性半胱天冬酶3的免疫组织化学染色在宫颈上皮中检测到凋亡细胞。在对照组和转基因小鼠的子宫颈上皮棘层中，苏木精和伊红染色也观察到罕见的凋亡细胞。在转基因、E-2处理的小鼠的宫颈上皮中，雌二醇降低了这些晚期凋亡细胞的百分比，但I3 C阻止了这种降低。这些数据证实了I3 C在体外对转化细胞的促凋亡作用，将观察结果扩展到宫颈癌细胞和DIM，并首次表明饮食I3 C导致体内靶组织细胞凋亡增加。
Dietary indole-3-carbinol (I3C) has clinical benefits for both cervical cancer and laryngeal papillomatosis, and causes apoptosis of breast cancer cells in vitro. We asked whether I3C and its major acid-catalyzed condensation product diindolylmethane (DIM), which is produced in the stomach after consumption of cruciferous vegetables, could induce apoptosis of cervical cancer cell lines. We also asked whether this effect could be observed in vivo. In vitro, both I3C and DIM caused accumulation of DNA strand breaks in three cervical cancer cell lines. Induction of apoptosis was confirmed by nuclear morphology, nucleosome leakage, altered cytoplasmic membrane permeability and caspase 3 activation. Neither I3C nor DIM caused apoptotic changes in normal human keratinocytes. In C33A cervical cancer cells, DIM was more potent than I3C [dose at which the number of viable cells was 50% of that in untreated cultures (LD50) = 50-60 mu mol/L for DIM and 200 mu mol/L for I3C in a mitochondrial function assay] and faster acting. Furthermore, I3C reduced Bcl-2 protein in a time- and dose-dependent manner. In HPV16-transgenic mice, which develop cervical cancer after chronic estradiol exposure, apoptotic cells were detected in cervical epithelium by TdT-mediated dUTP nick-end labeling staining and by immunohistochemical staining of active caspase 3 only in mice exposed to 17 beta -estradiol (E-2) and fed I3C. Rare apoptotic cells were also observed by hematoxylin and eosin staining in the spinous layer of the cervical epithelium in both control and transgenic mice. Estradiol reduced the percentage of these late-stage apoptotic cells in the cervical epithelium of transgenic, E-2-treated mice, but this reduction was prevented by I3C. These data confirm the proapoptotic action of I3C on transformed cells in vitro, extend the observations to cervical cancer cells and to DIM and show for the first time that dietary I3C results in increased apoptosis in target tissues in vivo.