| ObjectiveRS was administered in vitro to observe its antitumor activity in human breast carcinoma cell line MCF-7 and colon carcinoma cell line LOVO,and in vivo to observe its antitumor activity in human colon carcinoma cell line LOVO. The experiment was also try to clarify its antitumor mechanisms and observe its cardiotoxicity.MethodsAs the most useful and efficient anthracycline,epirubicin(EPI) was contrasted as the positive chemical treatment. MTT colorimetric assay was applied to detect cytotoxicity of RS in MCF-7 and LOVO cells. Apoptosis rate of cells double marked with Annexin V-FITC and PI was examined by flow cytometry. And,the alteration of wild type(WT) p53,bax and bcl-2 proteins expression was also observed. Ultrastructure change of MCF-7 and LOVO cell was observed under transmission electron microscope. Nude mice with colon carcinoma were established to conduct interference treatment. The mice were divided into three groups in random,the group of control,RS and EPI. RS and EPI was administered intraperitoneal injection to observe its antitumor activity in vivo. The heart,liver,kidney and spleen were conducted by pathological examination to observe its toxic effect of RS and EPI.Results1. Cytotoxicity in vitroGrowth restrain was observed in MCF-7 and LOVO cell when administered with different dose of R5 or EPI,and it was much more stronger when the dose was 10-4. 10-5 or 10-6mol/l. The effect was increased concomitant with the increasing of compound concentration and culture time.Apoptosis was observed since 6 hours after the MCF-7 and LOVO cell cultured with RS or EPI,and the effect was increased with the culture time extending and reached the highest peak in about 48 hours. The apoptotic rate decreased when the culture time was 72 hours. Different dose of R5 and EPI can all induced apoptosis of MCF-7 cell,and the apoptotic rate increased with compound concentration,but decreased when the concentration was higher than 5X 10-6 mol/1. It can also be observed in LOVO cell that the apoptotic rate began to decreased when the compound concentration was more than 1 X 10-6 mol/1. The decrease of protein bcl-2 and increase of protein bax and WT p53 were observed after MCF-7 and LOVO cell cultured with 10-6 mol/1 R5 or EPI for 48 hours. Ultrastructure of apoptotic MCF-7 and LOVO cells,observed by transmission electron microscope,had classic morphologic changes of apoptosis,cells shrinkage,chromatin condensation and concentration beside nuclear membrane,hyalomere emerging inside nuclear,membrane blebbing,microvillus decreasing. On the whole,the shape of cell wasintegra. 2. Therapeutic efficacy in vivoRS and EPI showed clear inhibitory activity against nude mice bearing human colon carcinoma cell line LOVO. Tumor-inhibition rate of R5 and EPI were 63.38% and 74.65% separately. Routine pathological section observation revealed a large area of necrosis associated with leukocyte infiltration in the normal surrounding tissues in EPI group,and many small area of necrosis associated with leukocyte infiltration in the normal surrounding tissues in R5 group. Part of myocardium cells disvolution was observed in R5 group,and no fragmentation in it. And much more myocardium cells disvolution were observed in EPI group. The cardiotoxicity of R5 is weaker than that of EPI. And mild suppression to leucocyte was observed both in R5 and EPI groups. None toxicity was observed in liver,kidney and spleen tissues.ConclusionsR5 had a clear ability of surpressing MCF-7 and LOVO cell in vitro,and its antitumor activity increased concomitant with the increasing of compound concentration and culture time. It affect phase S of LOVO and MCF-7 cells mainly. Its antitumor activity was associated with inducing apoptosis,which was up-regulated by expression of WT P53 and bax,and down-regulated by expression of bcl-2. RS showed clear inhibitory activity against nude mice bearing human colon carcinoma cell line LOVO. The cardiotoxicity of RS is weaker than that of EPI. It had mild suppression to leucocyt... |
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