ABSTRACT
Objective To study the expression and interactions of DNA methyltransferase 1 (DNMT1),enhancer of zeste homolog 2 (EZH2) and histone deacetylase 1 (HDAC1) in gastric cancer cell lines and tissue specimens.Methods The expression of DNMT1,EZH2 and HDAC1 was detected at mRNA and protein level in gastric cancer lines MKN28,SGC7901,BGC823,AGS,normal gastric epithelium cell line GES-1 and 10 pairs of fresh gastric cancer tissues and corresponding normal gastric tissues by real-time polymerase chain reaction and Western blot.Whether DNMT1,EZH2 and HDAC1 forming complex or not was detected by co-immunoprecipitation (Co-IP) in well-differentiated gastric cancer cell line MKN28,medium-differentiated gastric cancer cell line SGC7901,lowdifferentiated gastric cancer cell line BCG823,normal gastric epithelium cell line GES-1,mediumdifferentiated,medium to low-differentiated,low-differentiated gastric cancer tissues and corresponding normal gastric tissues.Results Compared with that of normal gastric epithelium cell and gastric tissue,the expression of DNMT1,EZH2 and HDAC1 in gastric cancer cell lines and gastric tissue was higher.The results of Co-IP indicated that DNMT1,EZH2 and HDAC1 formed complex in the high,medium,and poor differentiated gastric cancer cells and the medium,mediumlow,poor differentiated gastric cancer tissues,but not in normal gastric epithelium cell and tissue.Conclusion DNMT1,EZH2 and HDAC1 highly expressed in gastric cancer and there was interaction effects among them,which might be an important mechanism in the correlation between DNA methylation and histone modifications in gastric cancer.
ABSTRACT
Objective To investigate the effect of recombinant plasmid pshRNA-DNMT3b on expression of DNMT3b mRNA and protein and on the proliferation of bladder cancer T24 cells,and research the function of DNMT3b in the process of bladder tumor formation.Methods There were three groups in this study,which are blank controller,HK and pshRNA-DNMT3b(24h,48h,72h),respectively.T24 cells were cultured routinely and transfected by the recombinant plasmids with lipfectamine 2000.The cells were detected by methods of RT-PCR,western blot and MTT.The varying level of DNMT3b mRNA and expression protein,and the conditions of cellular survival rate were observed.Results The recombinant plasmids were successfully transfected into T24 cell lines.The grey valHe of RT-PCR elctrophoretogram was analyzed by the software of Gel-pro analyzer,the rate of blank controller,HK and pshRNA-DNMT3b(24h,48h,72h),was (99.56±1.24)%,(99.12±1.35)%,(75.77±1.42)%,(44.69±1.05)%and(20.52±0.89)%,respectively.The analytical resuit of western blot image was(99.43±1.28)%,(98.90±1.31)%,(67.83±1.02)%,(43.43±1.05)%and(21.92±0.89)%.There was no statistically difference in survival between blank control and HK(P＞0.05).The group of pshRNA-DNMT3b and other two groups had statistical difference only at the 72th hour and the cell inhibitory growth rate only increase 0.45%.Conclusions The recombinant ptasmid pshRNA-DNMT3b can inhibit the expression of mRNA and protein of DNMT3b effectively.However,it has slight function on inhibiting cell proliferation.