Linsalata Michele, Russo Francesco, Notarnicola Maria, Guerra Vito, Cavallini Aldo, Clemente Caterina, Messa Caterina
Laboratory of Biochemistry, Scientific Institute for Digestive Diseases, IRCCS Saverio de Bellis, Castellana G, (BA), Italy.
Nutr Cancer. 2005;52(1):84-93. doi: 10.1207/s15327914nc5201_11.
Polyamines and their rate-limiting enzyme, ornithine decarboxylase (ODC), are actively involved in cell growth and differentiation. The phytoestrogen genistein has been demonstrated to possess antitumor properties by influencing proliferation, differentiation, and apoptosis. The aim of this study was to investigate the effects of genistein at concentrations ranging from 0.01 to 100 microM on the polyamine biosynthesis, cell proliferation, and apoptosis in the estrogen receptor-positive DLD-1 human colon cancer cell line. Polyamine levels and ODC activity were evaluated by high performance liquid chromatography and radiometric technique, respectively. The proliferative response was estimated by [3H]-thymidine incorporation and the colorimetric 3-(4,5 di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Apoptosis was investigated by DNA fragmentation. Bax and Bcl-2 gene expressions were evaluated by multiplex-polymerase chain reaction. At concentration >or=1 microM, genistein decreased significantly the ODC activity and the polyamine levels. At the same concentration, genistein also increased significantly Bax mRNA expression, but not Bcl-2 mRNA expression. Higher concentrations (>or=10 microM) were needed to obtain a significant inhibition of cell proliferation and DNA fragmentation. The results of this study suggest that genistein can affect growth of DLD-1 cells by both decreasing polyamine biosynthesis and inducing apoptosis. However, further studies are required to assess the true ability of a soy rich diet in modifying colon cancer risk.
多胺及其限速酶鸟氨酸脱羧酶（ODC）积极参与细胞生长和分化。植物雌激素染料木黄酮已被证明可通过影响增殖、分化和凋亡而具有抗肿瘤特性。本研究的目的是调查浓度范围为0.01至100微摩尔的染料木黄酮对雌激素受体阳性的人结肠癌细胞系DLD-1中多胺生物合成、细胞增殖和凋亡的影响。分别通过高效液相色谱法和放射技术评估多胺水平和ODC活性。通过[3H] - 胸腺嘧啶核苷掺入和比色法3 - （4,5 - 二甲基噻唑 - 2 - 基） - 2,5 - 二苯基溴化四氮唑试验估计增殖反应。通过DNA片段化研究凋亡。通过多重聚合酶链反应评估Bax和Bcl - 2基因表达。在浓度≥1微摩尔时，染料木黄酮显著降低ODC活性和多胺水平。在相同浓度下，染料木黄酮还显著增加Bax mRNA表达，但不增加Bcl - 2 mRNA表达。需要更高浓度（≥10微摩尔）才能获得对细胞增殖和DNA片段化的显著抑制。本研究结果表明，染料木黄酮可通过降低多胺生物合成和诱导凋亡来影响DLD - 1细胞的生长。然而，需要进一步研究来评估富含大豆的饮食在改变结肠癌风险方面的真正能力。
