摘要目的 探讨二十二碳六烯酸(DHA)复合物的抗癌作用及其作用机制.方法 建立H22小鼠肝癌细胞的移植瘤动物模型,观察DHA复合物的体内抑瘤作用,采用体外细胞培养的方法 ,观察DHA复合物对宫颈癌HeLa细胞和胶质瘤U251细胞的体外抑瘤作用.采用电镜和荧光显微镜观察细胞形态的变化.Western blot法测定移植瘤组织中caspase-3蛋白的表达,逆转录聚合酶链反应(RT-PCR)检测HeLa细胞和U251细胞中Bel-2和Bax mRNA的表达.结果 DHA复合物对小鼠H22细胞移植瘤有明显的抑瘤作用,其低、中、高剂量组的抑瘤率分别为37.62%、48.55%和58.63%.在体外,随着剂量的增加,DHA复合物对HeLa细胞和U251的生长抑制率逐渐增高,Hela细胞的IC50为0.9814 μg/ml,U251细胞的IC50为0.3746 μg/ml.DHA复合物处理后,移植瘤细胞的细胞核呈分叶状,可见大小不等、致密的凋亡小体;HeLa细胞的细胞核内可见致密浓染的黄绿色荧光和碎片,分布在核周边,呈肾形或者半月形,核固缩,趋于碎裂.与CMC组比较,DHA复合物能明显促进caspase-3蛋白的表达,且DHA复合物剂最越高,caspase-3蛋白的表达升高越明显.DHA复合物能下调U251细胞中Bcl-2 mRNA的表达,上调Bax mRNA的表达,与CMC组比较,差异均有统计学意义(均P<0.01).结论 DHA复合物在体内外对多种肿瘤细胞有抑制作用,其抑瘤作用可能是通过抑制Bcl-2的表达、促进Bax和caspase-3的表达实现的.

abstractsObjective To study the anticancer effect in vitro and in vivo and mechanism of DHA compound. Methods Cervical cancer cell line HeLa cells, glioma cell line U251 cells and mouse hepatoma H22 tumor were used in this study. Transmission electron microscopy and flurescence microscopy were used to observe the morphological changes of cell apoptosis. Western blot was used to detect the expression of caspase-3. RT-PCR was used to determine the effect on Bcl-2 and Bax mRNA transcription in U251. Results Antitumor effect was observed in vivo and in vitro. Typical morphological changes were seen in cancer cells. The level of caspase-3 was significantly increased and the content of Bcl-2 mRNA was decreasd significantly, while the content of Bax mRNA was significantly increased in the U251 cells after treatment with DHA compound. Conclusion DHA compound can inhibit the growth of some types of tumors and the increase of caspase-3 and Bax mRNA and decrease of Bcl-2 mRNA may be involved in its mechamism of action.