摘要目的 探讨抗坏血酸(Asc)对胰腺癌PANC1细胞的生物学影响及其作用机制.方法 PANC1细胞用不同浓度(0～40 nmol/L) Asc处理24、48、72 h.采用四甲基偶氮唑蓝(MTT)法观察Asc对胰腺癌PANC1细胞增殖的影响,流式细胞仪检测细胞周期及凋亡率,倒置显微镜和透射电镜观察细胞形态,应用JC-1染色流式细胞仪检测线粒体膜电位.同时,观察Asc对抗氧化剂过氧化氢酶(catalase)及红细胞(RBC)预处理的PANC1细胞形态及线粒体膜电位的影响.结果 药理浓度Asc选择性抑制PANC1细胞增殖,并呈浓度、时间依赖性.5 mmol/L Asc处理后PANC1细胞被阻滞在G2/M期[ (32.55±7.14)％ 比(22.00±1.27)％,t=5.808,P＜0.05],但凋亡率未见增加[(1.98±1.80)％比(1.09±0.16)％].≥5 mmol/L Asc诱导PANC1细胞发生胀亡性死亡,细胞线粒体膜电位呈浓度依赖性明显降低.catalase及RBC预处理能明显抑制细胞线粒体膜电位的下降,减轻细胞发生胀亡的程度.结论 Asc在体外对胰腺癌PANC1细胞有明显的增殖抑制作用.Asc诱导PANC1细胞发生胀亡性死亡,而不是凋亡,其机制可能与线粒体膜电位下降有关.

abstractsObjective To investigate the biological effects and its mechanisms of ascorbic acid on pancreatic cancer PANC1 cells. Methods PANC1 cells were treated by ascorbic acid of different concentrations (0 ～40 mmol/L) for 24,48,72 hours.The proliferation of PANC1 cells was analyzed by MTT method; cell cycle and apoptosis were assessed by flow cytometry (FCM); inverted microscopy and transmission electron microscopy were used to observe cell morphology. The membrane potential of mitochondria were mearured by with JC-1 staining and FCM.Meanwhile,the changes of cell morphology and mitochondrial membrane potential induced by ascorbic acid after pretreatment with hydrogen peroxidescavenging enzyme (catalase) and red blood cells were also detected. Results Ascorbic acid in pharmacologic concentrations selectively inhibited the proliferation of PANC1 cells in a dose and time dependent manner.PANC1 cells were arrested in G2/M phase after treatment with 5 mmol/L ascorbic acid [ (32.55 ± 7.14)％ vs (22.00 ±1.27)％,t =5.808,P＜0.05],but there was no changes on apoptosis rate [ (1.98 ± 1.80)％ vs (1.09 ±0.16)％ ].Inverted microscope and transmission electron microscopy showed that oncosislike cell death of PANC1 cells was induced after treatment with ≥5 mmol/L ascorbic acid.Mitochondrial membrane potential of PANC1 cells was significantly lower than that of the control group in a dose dependent manner.The descent of mitochondrial membrane potential was significantly inhibited by pretreatment with catalase and red blood cells,and the degree of cell oncosis was attenuated.Conclusions Ascorbic acid significantly inhibited the proliferation of pancreatic cancer PANC1 cells in vitro.Ascorbic acid induced PANC1 cell oncosis,but not apoptosis.The possible mechanisms of inducing oncosis may be related to the descent of mitochondrial membrane potential.