纳豆脂肽诱导人乳腺癌细胞MCF-7凋亡的机制研究

目的:初步探讨纳豆脂肽诱导人乳腺癌细胞MCF-7凋亡的可能作用机制。方法:取对数生长期的MCF-7细胞,实验设4组,分别加入不同浓度(0、1、2、4μg/mL)的纳豆脂肽,于37℃培养箱中继续培养12 h后,收集细胞,采用流式细胞术检测纳豆脂肽对MCF-7细胞凋亡的影响;单细胞凝胶电泳检测纳豆脂肽对MCF-7细胞DNA损伤的影响;Western blot法检测纳豆脂肽对雌激素受体ERα和ERβ蛋白表达的影响。结果:与对照组比较,各浓度纳豆脂肽处理组均可诱导MCF-7细胞凋亡(P均<0.05);Olive尾矩和尾部DNA含量均明显增加(P<0.05或P<0.01),且4μg/mL纳豆脂肽组尾长亦明显增加(P<0.01)。纳豆脂肽浓度为4μg/mL时,ERα表达水平明显下降,ERβ表达水平明显上升,差异均具有统计学意义(P均<0.05)。结论:纳豆脂肽可能是通过影响MCF-7细胞内雌激素受体表达水平和引起DNA损伤来诱导MCF-7细胞发生凋亡。

Mechanisms of natto lipopeptide-induced apoptosis in MCF-7 cells

OBJECTIVE: To investigate the mechanisms of apoptosis induced by natto lipopeptide in MCF-7 cells. METHODS: Logarithmic growth phase of MCF-7 cells were treated with natto lipopeptide at different concentration(0,1,2,4μg/mL) in vitro and cultuerd at 37℃ incubator. Cells were collected after 12 h. Flow cytometry was used to detect apoptosis;single cell gel electrophoresis was used to detect DNA damage and Western blot for detection of estrogen receptors α and β expression levels. RESULTS: Natto lipopeptide could induce apoptosis in MCF-7 cells(P<0.05). Olive tail moment and tail DNA levels increased significantly(P<0.05 or P<0.01),and 4μg/mL natto lipopeptide group significantly increased tail length compared wie control group(P<0.01). Compared wie control group,natto lipopeptide of 4μg/mL also had significant effects on the expressions of ERα and ERβ(P<0.05). CONCLUSION: Natto lipopeptide exposure could change the expression levels of ERα and ERβ and damage DNA of MCF-7 cells,contributing to apoptosis.