β-紫罗兰酮诱导人乳腺癌细胞(ER^+)凋亡作用

Effect of β-ionone on apoptosis induction in MCF-7 human mammary cancer Er^+ cells

目的为了研究β-紫罗兰酮对雌激素阳性的人乳腺癌细胞(MCF-7)凋亡诱导作用的影响。方法采用细胞生长曲线,凋亡细胞的荧光显微镜和电镜观察,TUNEL方法及流式细胞光度术以及Western blot的检测方法,观察了用不同浓度β-紫罗兰酮(25、50、100和200μmol/L)对MCF-7细胞的抑制作用及诱导该细胞产生凋亡情况。结果β-紫罗兰酮可明显抑制MCF-7细胞生长,抑制率分别为6.57%、34.58%、65.22%和81.87%。通过荧光显微镜和电镜技术观察到了MCF-7细胞有凋亡的形态特征;TUNEL(末端脱氧核苷酸转移酶缺口末端标记)方法和流式细胞光度术均检测到β-紫罗兰酮可诱导MCF-7细胞产生凋亡,并随着β-紫罗兰酮浓度的增加,细胞凋亡率逐渐增加。TUNEL凋亡指数(AI)分别为20.74%(24h)和33.15%(48h);流式细胞光度术的凋亡指数(AI)分别为27.96%(24h)和38.59%(48h)。通过Western blotting方法观察到β-紫罗兰酮可对MCF-7的细胞增殖相关蛋白PCNA及bcl-2蛋白表达有明显地抑制作用,呈现明显地剂量-反应关系。结论β-紫罗兰酮可明显地抑制雌激素阳性(ER+)人乳腺癌MCF-7细胞的增殖,并诱导该细胞产生凋亡,其作用机制需要进一步探讨。

Objective To investigate the effect of β-ionone on cell apoptosis induction in Michigan Cancer Founda- tion-7 （ MCF-7 ） human mammary cancer cells positive to estrogens （ Er^＋ ）. Methods The MCF-7 cells were treated with various concentrations （25,50,100, and 200 μmol/L）of β-ionone and a negative control group was set. The growth curve of the cells was calculated; the morphological changes of apoptotic cells were observed with fluorescent and electronic mi- croscope ;terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL）assay, flow cytometry, and Western blot were employed to assess the inhibition and apoptosis of MCF-7 cells. Results The growth of MCF-7 cells was inhibited by β-ionone with the inhibitive rates of 6.57%, 34.58%, 65.22%, and 81.87% at the doses of 25,50,100, and 200 pumol/L, respectively, after 7 days＇ treatment. The morphological changes of apoptotic MCF-7 cells treated with different concentrations of β-ionone were observed. The frequency of apoptosis ascertained by TUNEL assay and flow cytometry showed an increasing trend with the increment of β-ionone concentration. The aoptosis index （AI）was 20. 74% （24 hours after the treatment）and 33.15 % （48 hours after the treatment）with TUNEL assay, and 27.96% （24 hours after the treat- ment） and 38.59% （48 hours after the treatment）with flow cytometry. The expressions of proliferating cell nuclear anti- gen （PCNA）and bcl-2 protein were inhibited in a dose-dependent manner. Conclusion β-ionone could inhibit the cell proliferation and induce apoptosis in MCF-7 cells and its exact mechanism needs to be studied further.