High Productivity of t-PA in CHO Cells Using Hypoxia Response Element

Abstract

The disolved oxygen level of any cell cultureenvironment has a critical effect on cellular metabolism.Specifically, hypoxia condition decreases cell viability andrecombinant protein productivity. In this work, to developCHO cells producing recombinant protein with high productivity,mamalian expresion vectors containing a human tissue-typeplasminogen activator (t-PA) gene with hypoxia responseelement (HRE) were constructed and stably transfected intoCHO cels. CHO/2HRE-t-PA cells produced 2-folds higherrecombinant t-PA production than CHO/t-PA cells in a Ba2+-alginate imobilized culture, and 16.8-folds in a repeatedbatch culture. In a non-aerated batch culture of suspension-adapted cels, t-PA productivity of CHO/2HRE/t-PA cels was4.2-folds higher than that of CHO/t-PA cells. Our resultsindicate that HRE is a useful tool for the enhancement ofprotein productivity in mamalian cell cultures.