Construction of a CHO cell expression vector carrying coamplification gene
LIU Guo qi,CHEN Xiao mi,XU Jing,SONG Hong bin,YU Chang ming,TONG Yi gang, WANG Hai taoInstitute of Microbiology and Epidemiology, Academy of MilitaryMedical Sciences, Beijing 100071,China
Aim To construct a CHO cell expression vector carrying coamplification gene. Methods Based on the mammalian expression vector pCI neo, a new mammalian expression vector pCdhfrl was constructed with dihydrofolate reductase(dhfr) gene as selection and coamplification marker. To evaluate its applied value, the enhanced green fluorescent protein(EGFP) gene was subcloned into pCdhfr l and the recombinant expression plasmid pFP was transfected into Chinese hamster ovary(CHO) cells mediated via liposome. Results After one cycle of amplification by methotrexate(Mtx), the CHO cell colonies stably expressed green fluorescent protein. Conclusion A model for the construction of engineered CHO cell line producing recombinant protein with CHO/DHFR system is established.