Results of recent studies in animal models of mammary carcinogenesis showed that the soybean isoflavone genistein is a chemopreventive agent. The objective of the present study was to determine whether soybean isoflavones can be used for the prevention of human breast carcinogenesis.Human adenocarcinoma cells that are either estrogen-receptor positive (such as MCF-7) or estrogen-receptor negative (such as MDA-MB-468) were used as our model system. Treatment of these cells with genistein concentrations of 15, 30, and 45 micromol/L resulted in cell growth inhibition, which was accompanied by the expression of maturation markers. Maturation was monitored by the induction of intracytoplasmic casein and lipids and the membrane protein intercellular adhesion molecule-1. These maturation markers were optimally expressed after 9 d of treatment with 30 mmol/L genistein. Both estrogen receptor-positive and -negative cells became differentiated in response to genistein treatments, suggesting that the antiestrogenic function of genistein is unrelated to the mechanism of cell differentiation. Daidzein, the other major isoflavone component of soybeans, did not induce differentiation in either MCF-7 or MDA-MB-468 cells.To explore the potential applications of this result, we used the nude mouse xenograft model of carcinogenesis. Treatment of either cell line with genistein before implantation into nude mice diminished the cells' tumorigenic potential. These data suggest that initiation of the differentiation program provides a protective effect against tumor growth in mouse xenografts.

最近，乳腺致癌的动物模型研究结果表明大豆异黄酮是化学防癌剂。目前的研究目的是确定大豆异黄酮是否可以用于防止人乳腺致癌。 
我们采用的模式系统中人腺癌细胞包括雌激素受体阳性细胞（如MCF-7）和雌激素受体阴性细胞（如MDA-MB-468）。用15, 30, 和45微摩尔/升不同浓度的金雀异黄素处理这些细胞，结果导致细胞生长抑制，并伴随着成熟标志的表达。成熟是通过诱导胞质内的酪蛋白，脂类，膜蛋白质胞间粘附分子1监控。这些最佳的成熟标记是在用金雀异黄素30毫摩尔/升处理 9天之后得到的。经金雀异黄素处理后，雌激素受体阳性细胞和雌激素受体阴性细胞都发生分化，这说明它的抗雌激素作用是和细胞分化机制无关的。黄豆苷元，和大豆异黄酮的其他成分，都不可能引起MCF-7 或 MDA-MB-468细胞分化。 
为了探讨它潜在的应用，我们采用裸鼠异种移植物模型，在植入裸鼠之前先用金雀异黄素处理两种中任一细胞系，结果减少了细胞发生肿瘤的可能性，这些结果均表明引导细胞程序化分化保护了裸鼠异种移植物模型对抗肿瘤生