Krishnan Prasad, Yan Karen J, Windler David, Tubbs Jesse, Grand Robert, Li Benjamin D L, Aldaz C Marcelo, McLarty Jerry, Kleiner-Hancock Heather E
Department of Pharmacology, Toxicology and Neuroscience, LSUHSC-Shreveport, Louisiana, USA.
BMC Cancer. 2009 Jul 29;9:259. doi: 10.1186/1471-2407-9-259.
Breast cancer is a major problem in the United States leading to tens of thousands of deaths each year. Although citrus auraptene suppresses cancer in numerous rodent models, its role in breast cancer prevention previously has not been reported. Thus, our goal was to determine the anticarcinogenic effects of auraptene against breast cancer.
The effects of auraptene on cell proliferation of MCF-7 and MDA-MB-231 human breast carcinoma cells in culture was assessed by measuring metabolism of a substrate to a formazan dye. Dietary effects of auraptene on tumor incidence, multiplicity and latency were studied in the N-methyl nitrosourea (MNU) induced mammary carcinogenesis model in female Sprague Dawley rats. The concentration of auraptene in rat tissues was analyzed by reverse phase HPLC. Cyclin D1 expression in MCF-7 cells and rat tumors was measured by western blot.
Auraptene (500 ppm) significantly delayed median time to tumor by 39 days compared to the MNU only group (p < 0.05, n = 24-26). Auraptene (10 microM) reduced Insulin like Growth Factor-1 (IGF-1, 10 ng/mL)-induced cyclin D1 expression by 40% in MCF-7 cells. In comparison, western blot analysis of rat mammary tumors (n = 10 per group) confirmed that auraptene (500 ppm) significantly reduced (p < 0.05) cyclin D1 expression by 49% compared to the MNU only group. Analysis of rat mammary tissue extract by HPLC with fluorescence detection indicated an average concentration (means +/- S.E.) of 1.4 +/- 0.5 microM and 1.8 +/- 0.3 microM in the normal mammary glands of the auraptene 200 ppm and 500 ppm groups, respectively. The concentration (means +/- S.E.) of auraptene in the mammary tumors of the auraptene 200 ppm group was 0.31 +/- 0.98 microM.
Overall, these observations suggest that the predominant effect of auraptene was to delay the development of tumors possibly through the suppression of cyclin D1 expression. These results point to the potential chemopreventive effects of auraptene in mammary carcinogenesis.
乳腺癌是美国的一个主要问题，每年导致数万人死亡。尽管柑橘奥瑞烯在众多啮齿动物模型中可抑制癌症，但其在乳腺癌预防中的作用此前尚未见报道。因此，我们的目标是确定奥瑞烯对乳腺癌的抗癌作用。
通过测量底物代谢为甲臜染料来评估奥瑞烯对培养的MCF-7和MDA-MB-231人乳腺癌细胞增殖的影响。在雌性斯普拉格-道利大鼠的N-甲基亚硝基脲（MNU）诱导的乳腺癌发生模型中研究奥瑞烯对肿瘤发生率、多发性和潜伏期的饮食影响。通过反相高效液相色谱法分析大鼠组织中奥瑞烯的浓度。通过蛋白质印迹法测量MCF-7细胞和大鼠肿瘤中细胞周期蛋白D1的表达。
与仅使用MNU的组相比，奥瑞烯（500 ppm）显著将肿瘤中位发生时间延迟了39天（p < 0.05，n = 24 - 26）。奥瑞烯（10 microM）使胰岛素样生长因子-1（IGF-1，10 ng/mL）诱导的MCF-7细胞中细胞周期蛋白D1表达降低了40%。相比之下，对大鼠乳腺肿瘤（每组n = 10）的蛋白质印迹分析证实，与仅使用MNU的组相比，奥瑞烯（500 ppm）使细胞周期蛋白D1表达显著降低（p < 0.05）49%。通过带荧光检测的高效液相色谱法分析大鼠乳腺组织提取物表明，奥瑞烯200 ppm组和500 ppm组正常乳腺中的平均浓度（均值±标准误）分别为1.4 ± 0.5 microM和1.8 ± 0.3 microM。奥瑞烯200 ppm组乳腺肿瘤中奥瑞烯的浓度（均值±标准误）为0.31 ± 0.98 microM。
总体而言，这些观察结果表明奥瑞烯的主要作用可能是通过抑制细胞周期蛋白D1的表达来延迟肿瘤的发展。这些结果表明奥瑞烯在乳腺癌发生中具有潜在的化学预防作用。
