Abstract: Objective To study the effect of human β-globin matrix attachment region (MAR) on transgene expression in stably transfected CHO cells. Methods The eapression vector was constructed , which contained the β-globin MAR in both sides of Chloramphenicol acetyltransferase (CAT) reporter gene expression cassette in cis, then transfected into CHO cells and screened under G418 selection. The CAT reporter gene expression was analyzed through ELISA method. Results It has showed that theβ-globin MAR could enhance the CAT gene expression 5.5-fold in stably transformed CHO cells, while the transgene expression variation among individuals of transformants was decreased. Conclusion MAR could increase transgene expression in stably transfected CHO cells.

Key words: matrix attachment region, transgene, gene engineering, CHO Cells