目的 探讨根皮素对人小细胞肺癌H446细胞增殖和凋亡的影响及可能的机制.方法 采用20、30、40μg/ml根皮素分别处理人小细胞肺癌H446细胞,并设不加药对照组.采用MTT法检测不同浓度根皮素对H446细胞作用24、48及72 h的细胞增殖率;采用流式细胞术检测不同浓度根皮素作用24h的H446细胞凋亡数量;采用Western blotting检测不同浓度根皮素对细胞浆中细胞色素C含量的影响;采用实时定量PCR(QPCR)检测不同浓度根皮素作用于H446细胞24 h pro-caspase-3、Bax和Bcl-2基因的表达.结果 20、30、40 μg/ml根皮素均能抑制H446细胞的增殖,且呈时间和剂量依赖性(P＜0.05);流式细胞术检测显示,对照组细胞的凋亡比例为(4.23±0.25)％,经20、30、40 μg/ml根皮素处理后细胞的凋亡比例分别增加到(12.97±0.21)％、(18.48±0.24)％、(33.61±0.27)％,与对照组比较,差异有统计学意义(P＜0.05);此外,根皮素剂量依赖性地增加细胞浆中细胞色素C的含量和pro-caspase-3 mRNA和BaxmRNA的表达,同时抑制Bcl-2 mRNA的表达(P＜0.05).结论 根皮素能够抑制H446细胞的增殖,其机制可能为通过调节线粒体中细胞色素C的释放和凋亡相关分子的表达促进H446细胞的凋亡.%Objective To investigate the effects and mechanisms of phloretin on the proliferation and apoptosis of human small cell lung cancer H446 cells.Methods H446 cells were treated with 20,30 or 40 μg/ml phloretin,and cells untreated were set as control.The proliferative rate of H446 cells treated with phloretin for 24,48 and 72 h was detected by MTT assay;Apoptosis of cells treated with varied doses of phloretin was evaluated by flow cytometry method;The content of cytochrome C in cytosol was assessed by Western blotting method;Besides,mRNA expression of pro-caspase-3,Bax and Bcl-2 were examined by real-time PCR(QPCR).Re sults The dose of 20,30 or 40 μg/ml phloretin could inhibite the proliferation of H446 cells in a dose and time dependent manner(P ＜0.05).Flow cytometry method showed that the apoptotic ratio of control group was (4.23 ±0.25)％,much lower than (12.97± 0.21) ％,(18.48±0.24) ％ and(33.61±0.27) ％ treated by 20,30 or 40 μg/ml phloretin.Besides,the protein content of cytochrome C in cytosol was up-regulated by phloretin in a dose-dependent manner(P＜0.05).Phloretin could dose-dependently decrease the expression of Bcl-2 mRNA(P＜0.05) and increase the mRNA expression of pro-caspase-3 and Bax(P＜0.05).Conclusion Phloretin can inhibit the proliferation of H446 cells and induce apoptosis by interfering the release of cytochrome C from mitochondria to cytosol and the mRNA expression of pro-caspase-3,Bax and Bcl-2.
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