ABSTRACT
Objective To investigate the effect of different promoters on the expression level of transgene containing MAR expression vector in recombinant CHO cells.Methods The CMV promoter and 3-globin MAR were amplified by PCR,then CMV promoter was replaced the SV40 promoter in pCAT1 for constructing the expression vector droved by CMV promoter.The control vectors of pCAT1 and pCAT2 without containing MAR were simultaneously transfected into the CHO cells.Then the stably transfected cell line was screened by G418.The CAT gene expression level was analyzed by ELISA.Results The expression level of CAT enzyme in the cells transfected with MAR-containing vectors was increased compared with the cells transfected by pCATG and pCAT3 vectors without containing MAR,which were increased by 1.75 and 1.25 times respectively(P＜0.05);but CAT enzyme expression level in the pCAT1 transfected cells droved by SV40 promotor with the MAR-containing expression vectors was 1.4 times higher than that in the pCAT2 vector droved by the CMV promoter(P＜0.05).Conclusion MAR can enhance the transgene expression level in stably recombinant CHO cells,and the promoting efficiency of SV40 promoter and MAR combination is superior to that of CMV promoter and MAR combination.