桦褐孔菌提取物体外抗肿瘤活性及对细胞周期的影响

目的 研究桦褐孔菌提取物的抗肿瘤活性及对人乳腺癌MCF-7 细胞周期的影响及其可能机制。方法 使用细胞计数试剂盒(cell counting kit-8,CCK-8)检测桦褐孔菌提取物对HepG2、A549、SGC-7901、HeLa和MCF-7细胞增殖的抑制作用并计算半数抑制浓度(half maximal inhibitory concentration,IC₅₀);选择抑制效果最好的MCF-7细胞株,观察其作用后细胞的形态学改变、细胞凋亡率和细胞周期的变化;并通过Western Blot实验检测细胞周期相关蛋白Cyclin D1、CDK4、PCNA和NUSAP1的表达。结果 桦褐孔菌提取物可有效抑制HepG2、A549、SGC-7901、HeLa和MCF-7细胞增殖,作用48 h后的IC₅₀分别为2.34、3.71、2.24、2.27、0.59 mg/ml;桦褐孔菌提取物可引起MCF-7细胞显著的形态学改变;可诱导MCF-7细胞凋亡,与对照组相比,差异有统计学意义(P<0.05或P<0.01);并明显影响MCF-7细胞的细胞周期分布,使细胞阻滞于S期(P＜0.01);桦褐孔菌提取物可抑制MCF-7细胞中Cyclin D1、CDK4、PCNA、NUSAP1蛋白的表达,与对照组比较,差异均有统计学意义(P<0.05)。结论 桦褐孔菌提取物可抑制多种组织来源的肿瘤细胞增殖,其中对MCF-7细胞抑制效果最好,可以诱导细胞凋亡,阻滞细胞周期达到抗肿瘤作用,可能是通过下调Cyclin D1、CDK4、PCNA和NUSAP1的蛋白表达来调控细胞周期,从而抑制肿瘤细胞过度增殖。本实验为桦褐孔菌提取物的药用开发提供新的方法和思路。

Anti-tumor activity of inonotus obliquus extracts and its effect on cell cycle in vitro

Objective To study the anti-tumor activity of inonotus obliquus extracts, its effect on human breast cancer MCF-7 cell cycle and the probable mechanism. Methods Cell counting kit-8 (CCK-8) was used to determine the inhibitory effect of inonotus obliquus extracts on the proliferation of HepG2, A549, SGC-7901, HeLa and MCF-7 cells and to calculate the half-maximal inhibitory concentration (IC₅₀). MCF-7 cells most sensitive to inonotus obliquus extracts were selected to observe morphological changes of the cells after treatment and the changes in cell apoptosis rate and cell cycle. The protein expression of Cyclin D1, CDK4, PCNA and NUSAP1 was detected by Western blot. Results Inonotus obliquus extracts could effectively inhibit the proliferation of HepG2, A549, SGC-7901, HeLa and MCF-7 cells with IC₅₀ (48 h) of 2.34 mg/ml, 3.71 mg/ml, 2.24 mg/ml, 2.27 mg/ml and 0.59 mg/ml, respectively. Inonotus obliquus extracts could cause obvious morphological changes of MCF-7 cells, and also could induce apoptosis in MCF-7 cells, and the difference was statistically significant as compared with the control group (P<0.05 or P<0.01). Inonotus obliquus extracts could significantly affect cell cycle distribution of MCF-7 cells, and lead to cell block in the S phase (P<0.01). Inonotus obliquus extracts could inhibit the protein expression of Cyclin D1, CDK4, PCNA and NUSAP1 in MCF-7 cells, showing statistically significant differences as compared with the control group (all P<0.05). Conclusions Inonotus obliquus extracts can significantly inhibit the proliferation of tumor cells from a variety of tissue sources, of which MCF-7 cells are the most sensitive to the extracts. Inonotus obliquus extracts can induce cell apoptosis and affect cell cycle by down-regulating the protein expression of Cyclin D1, CDK4, PCNA and NUSAP1. These findings provide novel information for clinical application of inonotus obliquus extracts.