Influence of antiestrogens on EGF- and IGF-I-mediated proliferation of human breast cancer cells.
Influence of antiestrogens on EGF- and IGF-I-mediated proliferation of human breast cancer cells.
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抗雌激素对 EGF 和 IGF-I 介导的人乳腺癌细胞增殖的影响。
DOI：
10.1007/s11626-999-0039-z
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Pento,JT
中科院分区：
文献类型：
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作者：
Tong,GM;Rajah,TT;Pento,JT
尊敬的编辑：据报道，抗雌激素通过拮抗雌二醇的促有丝分裂作用来抑制雌激素受体（ER）阳性MCF-7细胞的生长，因此不应抑制无雌激素培养基中的增殖。然而，已经证明，抗雌激素药物在没有雌二醇的情况下抑制MCF-7细胞生长，这表明它们部分地通过ER的雌二醇拮抗作用以外的机制起作用（15）。此外，某些生长因子对细胞增殖的活性受到雌激素和抗雌激素的影响（4，5）。为了更完整地定义抗雌激素的抗增殖作用机制，本研究的目的是比较三种抗雌激素[他莫昔芬（TAM），ICI-182，780（ICI）和类似物（AII）]，它们在胰岛素样生长因子-1（IGF-1）或表皮生长因子（EGF）诱导的MCF-7细胞增殖的化学结构和生物学机制上不同。7人乳腺癌细胞在无血清条件下。MCF-7细胞获自Michigan Cancer Foundation，并如前所述在RPMI 1640培养基中作为单层培养物生长（8）。收获后，将细胞以104个细胞/孔的浓度接种到96孔组织培养板中的含有5%小牛血清的RPMI中，并使其贴壁过夜。在处理前24小时，用RPMI+5%TCH（确定的血清替代物，Celox Corporation，霍普金斯，MN）替换培养基。在第1天开始用生长因子（10 - 10 M）、抗雌激素（10-6 M）、雌二醇（10-9 M）或其组合进行实验处理，并且隔日更换含有处理的培养基。根据先前剂量相关观察结果，使用10至M EGF或IGF-I进行这些实验（13）。如前所述，用中性红染料法测定细胞增殖（2）。在处理第7天定量细胞增殖，并报告为对照处理细胞的百分比。为了统计学目的，每个实验中包括每个处理的三份样品，并且三个实验的组合结果被视为在处理组合内具有独立观察结果的双因素方差分析。此外，All和ICI可逆转IGF-I的作用（P< 0.05）。最后，图1显示ICI和TAM，而不是All，在雌二醇不存在的情况下降低MCF-7细胞的基础增殖（P< 0.05）。EGF+雌二醇或IGF-I+雌二醇的组合不产生MCF-7细胞增殖的累加刺激（图2）。3种抗雌激素均能逆转雌二醇单独作用的MCF-7细胞增殖抑制作用（P< 0.05）。TAM可抑制EGF+雌二醇联合诱导的细胞增殖。AII和TAM对IGF-1 + E2的促增殖作用有明显的抑制作用（P< 0.05）。添加雌二醇
Dear Editor: It has been reported that antiestrogens inhibit the growth of estrogen receptor (ER)-positive MCF-7 cell growth by antagonizing the mitogenic effects of estradiol, and thus should not inhibit proliferation in estrogen-free media. However, it has been demonstrated that antiestrogens inhibit MCF-7 cell growth in the absence of estradiol, suggesting that they operate in part through mechanisms other than estradiol antagonism at the ER (15). Further, the activity of certain growth factors on cell proliferation is influenced by both estrogens and antiestrogens (4, 5). To more completely define the antiproliferative mechanisms of action of antiestrogens, the objective of the present study was to compare the antiproliferative activities of three an-tiestrogens [tamoxifen (TAM), ICI-182,780 (ICI) and Analog (AII)] which differ in chemical structure and biological mechanism on insulin-like growth factor-1 (IGF-1) or epidermal growth factor (EGF)-induced proliferation of MCF-7 human breast cancer cells under serum-free conditions. The MCF-7 cells were obtained from the Michigan Cancer Foundation and grown as monolayer cultures in RPMI 1640 media as previously described (8). After harvesting, cells were seeded into 96-well tissue culture plates at a concentration of 104 cells/well in RPMI containing 5% calf serum and allowed to attach overnight. The medium was replaced with RPMI+ 5% TCH (defined serum replacement, Celox Corporation, Hopkins, MN) 24 h before treatment. Experimental treatment with growth factor (10-'0 M), antiestrogen (10-6 M), estradiol (10-9 M) or a combination was initiated on Day 1 and medium containing treatments was replaced on alternate days. These experiments were conducted with 10-to M EGF or IGF-I, based on results of previous dose-related observations (13). Cell proliferation was determined with the neutral red dye method as previously described (2). Cell proliferation was quanti-tated on treatment Day 7 and reported as a percentage of control-treated cells. For statistical purposes, triplicate samples of each treatment were included in each experiment and the combined results of three experiments were viewed as a two-factor analysis of variance having independent observations within treatment combi-nations.All three antiestrogens inhibited EGF-induced proliferation of MCF-7 cells (P< 0.05)(Fig. 1). Additionally, All and ICI reversed the effects of IGF-I (P< 0.05). Finally, Fig. 1 shows that ICI and TAM, but not All, reduced basal proliferation of MCF-7 cells in the absence of estradiol (P< 0.05). The combination of either EGF+ estradiol or IGF-I+ estradiol did not produce an additive stimulation of MCF-7 cell proliferation (Fig. 2). All three antiestrogens reversed the effect of estradiol alone on MCF-7 cell proliferation (P< 0.05). Cell proliferation produced by the combination of EGF+ estradiol was inhibited by TAM. Pro-liferation produced by the combination of IGF-I+ estradiol was inhibited by AII and TAM (P< 0.05). The addition of estradiol