Demethylation effect of emodin combined with 5AzA-cdR on tumor suppressor gene p16, RASSF1A and ppENK in subcutaneous xenografts of pancreatic cancer nude mice model / 中华胰腺病杂志

ABSTRACT

Objective To investigate whether emodin combined with 5AzA-cdR can enhance the demethylation of tumor suppressor genes p16,RASSF1A and ppENK in nude mice with subcutaneously transplanted pancreatic cancer.Methods Pancreatic cancer cells Panc1 burdened subcutaneous xenograft nude mice model was established,which were randomly divided into control group,emodin group,5AzA-cdR group and emodin combined 5AzA-cdR group (combined group).The growth of transplanted tumors wasobserved in each group.Methylation specific PCR (MSP) was used to detect the methylation levels of p16,RASSF1A and ppENK in the xenograft tumor tissue among three groups.The mRNA and protein expression of three tumor suppressor genes were detected by FQ-PCR and Western blotting,respectively.Results The weight of xenografts in the control group,emodin group,5AzA-cdR group,and combination group were (0.28 ±0.01),(0.17 ± 0.01),(0.12 ± 0.02),(0.08 ± 0.01)g,respectively.The tumor volume was (517 ±0.02),(382 ± 0.01),(232 ± 0.03),(169 ± 0.01) mm3.The methylation levels of p16 were 1.00 ± 0.00,0.89 ± 0.02,0.63 ± 0.02,and 0.19 ± 0.01;the methylation levels of RASSF1A were 1.00 ± 0.00,0.88 ± 0.02,0.51 ± 0.01,and 0.32 ± 0.01;the methylation degree of ppENK was 1.00 ± 0.00,0.92 ± 0.02,0.77 ± 0.02 and 0.31 ± 0.01,respectively.The expression of p16 mRNA was 1.00 ± 0.00,1.71 ±0.02,2.67 ± 0.02,3.81 ± 0.01.The expression of RASSF1A mRNA was 1.00 ± 0.00,1.92 ±0.02,2.73 ± 0.03,3.77 ± 0.01.The expression of ppENK mRNA was 1.00 ± 0.00,1.69 ± 0.03,2.17 ± 0.02 and 4.28 ± 0.01.The expression of p16 protein was 1.00 ± 0.00,1.71 ± 0.02,2.67 ± 0.02,3.81 ± 0.01;the expression of RASSF1A protein was 1.00 ± 0.00,1.92 ± 0.02,2.73 ± 0.03.3.77 ± 0.01;ppENK protein expression levels were 1.00 ±0.00,1.69 ±0.03,2.17 ±0.02,4.28 ±0.01.The weight and volume of xenografts in the three treatment groups were significantly smaller than those in the control group.The methylation of three tumor suppressor genes was lower than that of the control group,and the expression of tumor suppressor mRNA and protein was all significantly higher than the control group,which the combination drug group was also significantly stronger than that in emodin group and 5AzA-cdR group,and the differences were statistically significant (P ＜ 0.05 or ＜ 0.01).Conclusions The combination of emodin and 5AzA-cdR can enhance the demethylation effect of 5A6A-cdR on the tumor suppressor genes p16,RASSF1A and ppENK in the tumor tissue of pancreatic cancer xenograft model.