Xu Pingping, Ye Weiping, Li Hong, Lin Shu-Hong, Kuo Chieh-Ti, Feng Eric, Lin Young C
Jinhua College of Profession and Technology, Jinhua, Zhejiang 321017, P.R. China.
Mol Med Rep. 2010 Sep-Oct;3(5):795-800. doi: 10.3892/mmr.2010.342. Epub 2010 Jul 26.
Breast cancer is the leading type of cancer in women in the United States. One of the known risk factors of breast cancer is obesity. Leptin is a product of the obese (ob) gene and plays an important role in breast cancer development. Its expression is up-regulated in obesity and it promotes breast cancer cell growth. Exposure to environmental estrogenic disruptors has been found to be directly related to the increase in the incidence of breast cancer. Zeranol (Z) is a non-steroidal anabolic growth promoter with potent estrogenic activity that is widely used in the US beef industry. The objective of this study was to determine the mechanisms of Z- and leptin-induced proliferation of primary cultured human breast cancer epithelial cells (HBCECs). A cell proliferation assay was used to determine the extent to which Z is capable of enhancing the mitogenic activity of leptin in HBCECs. RT-PCR was used to explore the possible mechanisms by quantifying the transcription of cyclin D1 and ObR genes. Our results demonstrated that when the HBCECs were pre-treated with 3 nM leptin for 24 h, the sensitivity to Z exposure greatly enhanced the mitogenic action of leptin. The experimental data observed show that there is interaction between leptin and Z in HBCEC growth.
乳腺癌是美国女性中最主要的癌症类型。肥胖是已知的乳腺癌风险因素之一。瘦素是肥胖（ob）基因的产物，在乳腺癌发展中起重要作用。其表达在肥胖状态下上调，并促进乳腺癌细胞生长。已发现接触环境雌激素干扰物与乳腺癌发病率增加直接相关。玉米赤霉醇（Z）是一种具有强大雌激素活性的非甾体类合成代谢生长促进剂，在美国牛肉行业广泛使用。本研究的目的是确定Z和瘦素诱导原代培养的人乳腺癌上皮细胞（HBCECs）增殖的机制。采用细胞增殖试验来确定Z增强瘦素在HBCECs中促有丝分裂活性的程度。利用逆转录聚合酶链反应（RT-PCR）通过定量细胞周期蛋白D1和ObR基因的转录来探索可能的机制。我们的结果表明，当HBCECs用3 nM瘦素预处理24小时后，对Z暴露的敏感性极大地增强了瘦素的促有丝分裂作用。观察到的实验数据表明，在HBCEC生长过程中瘦素与Z之间存在相互作用。
