Effects of the grub extract on apoptosis of MCF-7 human breast cancer cell line

AIM:To investigate the apoptotic pathway of MCF-7 breast cancer induced by the grub extract in vitro.METHODS:MTT assay was used to determine the effect of the grub extract on proliferation of MCF-7 human breast cancer cell line and cell toxicity.Morphological changes of the apoptosis in cancer cells were observed by HE staining through invert microscope,light microscope,AO/EB double fluorescent staining under fluorescent microscope.FCM was used to assay the change of apoptotic rate.The expression of Bcl-2,Fas,caspase-9,caspase-3 in apoptotic pathway was detected with immunocytochemical method before and after exposure to the grub extract,and the effect of that on apoptotic pathway was explored.RESULTS:(1)The MTT test showed that the growth of MCF-7 human breast cancer cell line was significantly inhibited by the grub extract in dose and time dependent manners.The inhibitory rate in exposure group was significantly different from that in control group(P0.01).(2)Morphological changes of apoptosis including nuclear condensation,fragment and apoptosis body formation were observed by invert microscope.(3)The MCF-7 human breast cancer cells in experimental group by HE staining showed nuclear condensation and blue-black,cytoplasm slight red,nuclear chromatin condensation and fragment shape,apoptosis body formations.(4)Apoptosis in the experimental group was observed by AO/EB double fluorescent staining under fluorescent microscope.(5)FCM assay indicated that apoptotic rate increased significantly in time dependent manner in experimental group.(6)The expression of Bcl-2 was down-regulated,while that of Fas,caspase-3,caspase-9 was up-regulated,compared with control group(P0.01).CONCLUSION:(1)The proliferation of MCF-7 human breast cancer cell line can be inhibited significantly by the grub extract in vitro.(2)The mechanism of effect of the grub extract on MCF-7 human breast cancer cell line might be mediated by down-regulation of Bcl-2 and up-regulation of Fas,caspase-3,caspase-9.This type of apoptosis' starting and performing is through death receptor pathway and mitochondrial pathway.