| Objectives To investigate the antitumor effect of S-allylmercaptocysteine(SAMC)in vivo and to improve the efficacy of liver injury induced by chemotherapy by human breast cancer MCF-7 cell line xenograft nude mice model.Methods The human breast cancer MCF-7 cells were cultured and then transplanted into nude mice by subcutaneous injection of single cell suspension.In the first chapter,40 nude mice were randomly divided into four groups: normal saline group,paclitaxel group,low dose SAMC group and high dose SAMC group.In the second chapter,20 nude mice with successful modeling were randomly divided into two groups: low-dose SAMC combined with paclitaxel and high-dose SAMC combined with paclitaxel.The saline group and the paclitaxel group were used as the common control group in the second chapter.Paclitaxel group was injected intraperitoneally with paclitaxel 10 mg · kg-1,low dose of SAMC group was intraperitoneally injected with SAMC 150 mg · kg-1,high dose of SAMC group was given intraperitoneal injection of SAMC 300 mg · kg-1,Saline saline group given saline 0.2ml / times.The combination groups were administered at intervals of 6 hours.The body weight was measured before each administration,and administered three times a week for two days and for a total of 3 weeks.During the intervention to observe the general situation of nude mice,after the completion of anesthesia completely peel the tumor tissue and blood collection,and then all the nude mice were sacrificed.Histopathological examination was performed to observe the morphology of the transplanted tumor tissue by HE staining.The expression of VEGF and caspase-3 protein was detected by immunohistochemistry.Blood samples of nude mice were used to measure the biochemical indices of alanine aminotransferase(ALT),aspartate aminotransferase(ALT),alkaline phosphatase(SOD)and glutathione peroxidase(GSH).Liver tissue samples were stained with HE for pathological observation of cell morphology,and then were observed the ultrastructural changes under scanning electron microscope.SPSS17.0 was used to analyze the data.The data were expressed as mean ± standard deviation(x?±s).One-way ANOVA was used to compare the differences between the groups.LSD was used to compare the variance between the two groups.Dunnett’s T3 test was used to test the variance.P <0.05 was considered statistically significant.Results The first part: About 9 days later of breast cancer MCF-7 cell single-cell suspension subcutaneous injection,the transplanted tumor grew under skin.Its shape was irregular and the boundary was clear.Besides the tissue was hard and poor mobility.When the diameter of the subcutaneous nodules is greater than 5mm,the model is constructed successfully.The tumor inhibition rates of low dose group,high dose group and paclitaxel group were 22.62%,31.48% and 37.05% respectively,which were statistically significant compared with the normal saline group.There was significant difference between the low dose group and the high dose group and the paclitaxel group(P <0.05),but there was no significant difference between the high dose group and the paclitaxel group(P> 0.05).The results of HE staining showed that the tumor cells in the saline group were closely arranged and the cell volume was irregular.In the low dose group and the high dose group,there were also different degree of cell necrosis,and the tumor tissue of the paclitaxel group showed a large area of cell necrosis,the cell structure disappeared and the necrotic area was homogeneous red dye.The expression of caspase-3 protein was detected by immunohistochemistry in the cytoplasm and the partial membrane.The positive expression product of caspase-3 was brown and yellow.The expression level of caspase-3 was higher than that of saline group(P <0.05)The The expression of high dose group was higher than that of low dose group,but lower than that of paclitaxel group,the difference was statistically significant(P <0.05).VEGF expression in the cytoplasm of breast cancer cells,stained cells can be seen after the brown particles,was lumps or flaky distribution,compared with the saline group,the remaining groups of VEGF expression was significantly reduced,the difference was statistically significant(P <0.05).The expression of high dose group was lower than that of low dose group,but higher than that of paclitaxel group,the difference was statistically significant(P <0.05).The second part:: SAMC combined with paclitaxel significantly reduced the levels of ALT,AST and ALP caused by paclitaxel-induced liver injury(P <0.05),and showed a dose-dependent relationship.Compared with the saline control group,the level of MDA in the paclitaxel group was significantly increased,and the levels of GSH and SOD were significantly decreased(P <0.05).Compared with the paclitaxel group,the low dose combined with the paclitaxel group and the high dose combined with the paclitaxel group decreased by 28%(P <0.05)and 49%(P <0.05).Compared with the GSH level in the paclitaxel group,the low and high dose combined with the paclitaxel group increased by 29.83%(P <0.05)and 67.41%(P <0.05),respectively.Compared with the SOD level in the paclitaxel group,the low and high dose combined with the paclitaxel group increased by 25.37%(P <0.05)and 48.52%(P <0.05).The results of HE staining showed that the structure of hepatic lobules was clear and complete in the liver tissue of nude mice in saline group,and the hepatic cords were arranged radially in the central vein of lobular vein.Paclitaxel group microscopic hepatocellular dysplasia,cytoplasm loose,sinusoidal structure blurred.After treatment with SAMC,the degree of liver cell degeneration was improved with different degrees.The results of liver electron microscopy showed that the nuclei of the hepatocytes in the saline group were elliptic or round,the nucleus membrane was continuous and smooth,and a large number of mitochondria were found in the cells.The mitochondrial membrane structure was clear.The nuclear membrane of the paclitaxel group was rough and blurred,the number of intracellular mitochondria was significantly reduced,the rough endoplasmic reticulum arranged more dispersed disorder,and the cell matrix appeared more obvious cavitation.Compared with the paclitaxel group,the nuclear and nuclear lesions of the low and high doses combined with the paclitaxel group were reduced and the number of mitochondria increased.Conclusions 1 SAMC has a significant inhibitory effect on the growth of nude mice breast cancer subcutaneous transplanted tumor.2 In human breast cancer MCF-7 cells of nude mice,SAMC can up-regulate the expression of caspase-3 protein and down-regulates the expression of VEGF protein in transplanted tumor tissue.3 SAMC can increase the level of GSH and SOD in liver,decrease the level of MDA and improve the damage of liver function caused by paclitaxel,suggesting that its mechanism may be related to its own antioxidant function. |
PDF Full Text Request